micro-ECC for mbed, ported from GCC version from Github,
Dependents: mbed_microECC Wallet_v1
Revision 0:b6fdeddc0bc9, committed 2017-09-07
- Comitter:
- allankliu
- Date:
- Thu Sep 07 12:10:11 2017 +0000
- Commit message:
- Init version, ported from GCC version of uECC of Github. Assembly optimization for thumb2 is disabled.
Changed in this revision
diff -r 000000000000 -r b6fdeddc0bc9 asm_arm.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/asm_arm.h Thu Sep 07 12:10:11 2017 +0000 @@ -0,0 +1,820 @@ +/* Copyright 2015, Kenneth MacKay. Licensed under the BSD 2-clause license. */ + +#ifndef _UECC_ASM_ARM_H_ +#define _UECC_ASM_ARM_H_ + +#if (uECC_SUPPORTS_secp256r1 || uECC_SUPPORTS_secp256k1) + #define uECC_MIN_WORDS 8 +#endif +#if uECC_SUPPORTS_secp224r1 + #undef uECC_MIN_WORDS + #define uECC_MIN_WORDS 7 +#endif +#if uECC_SUPPORTS_secp192r1 + #undef uECC_MIN_WORDS + #define uECC_MIN_WORDS 6 +#endif +#if uECC_SUPPORTS_secp160r1 + #undef uECC_MIN_WORDS + #define uECC_MIN_WORDS 5 +#endif + +#if (uECC_PLATFORM == uECC_arm_thumb) + #define REG_RW "+l" + #define REG_WRITE "=l" +#else + #define REG_RW "+r" + #define REG_WRITE "=r" +#endif + +#if (uECC_PLATFORM == uECC_arm_thumb || uECC_PLATFORM == uECC_arm_thumb2) + #define REG_RW_LO "+l" + #define REG_WRITE_LO "=l" +#else + #define REG_RW_LO "+r" + #define REG_WRITE_LO "=r" +#endif + +#if (uECC_PLATFORM == uECC_arm_thumb2) + #define RESUME_SYNTAX +#else + #define RESUME_SYNTAX ".syntax divided \n\t" +#endif + +#if (uECC_OPTIMIZATION_LEVEL >= 2) + +uECC_VLI_API uECC_word_t uECC_vli_add(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + wordcount_t num_words) { +#if (uECC_MAX_WORDS != uECC_MIN_WORDS) + #if (uECC_PLATFORM == uECC_arm_thumb) || (uECC_PLATFORM == uECC_arm_thumb2) + uint32_t jump = (uECC_MAX_WORDS - num_words) * 4 * 2 + 1; + #else /* ARM */ + uint32_t jump = (uECC_MAX_WORDS - num_words) * 4 * 4; + #endif +#endif + uint32_t carry; + uint32_t left_word; + uint32_t right_word; + + __asm__ volatile ( + ".syntax unified \n\t" + "movs %[carry], #0 \n\t" + #if (uECC_MAX_WORDS != uECC_MIN_WORDS) + "adr %[left], 1f \n\t" + ".align 4 \n\t" + "adds %[jump], %[left] \n\t" + #endif + + "ldmia %[lptr]!, {%[left]} \n\t" + "ldmia %[rptr]!, {%[right]} \n\t" + "adds %[left], %[right] \n\t" + "stmia %[dptr]!, {%[left]} \n\t" + + #if (uECC_MAX_WORDS != uECC_MIN_WORDS) + "bx %[jump] \n\t" + #endif + "1: \n\t" + REPEAT(DEC(uECC_MAX_WORDS), + "ldmia %[lptr]!, {%[left]} \n\t" + "ldmia %[rptr]!, {%[right]} \n\t" + "adcs %[left], %[right] \n\t" + "stmia %[dptr]!, {%[left]} \n\t") + + "adcs %[carry], %[carry] \n\t" + RESUME_SYNTAX + : [dptr] REG_RW_LO (result), [lptr] REG_RW_LO (left), [rptr] REG_RW_LO (right), + #if (uECC_MAX_WORDS != uECC_MIN_WORDS) + [jump] REG_RW_LO (jump), + #endif + [carry] REG_WRITE_LO (carry), [left] REG_WRITE_LO (left_word), + [right] REG_WRITE_LO (right_word) + : + : "cc", "memory" + ); + return carry; +} +#define asm_add 1 + +uECC_VLI_API uECC_word_t uECC_vli_sub(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + wordcount_t num_words) { +#if (uECC_MAX_WORDS != uECC_MIN_WORDS) + #if (uECC_PLATFORM == uECC_arm_thumb) || (uECC_PLATFORM == uECC_arm_thumb2) + uint32_t jump = (uECC_MAX_WORDS - num_words) * 4 * 2 + 1; + #else /* ARM */ + uint32_t jump = (uECC_MAX_WORDS - num_words) * 4 * 4; + #endif +#endif + uint32_t carry; + uint32_t left_word; + uint32_t right_word; + + __asm__ volatile ( + ".syntax unified \n\t" + "movs %[carry], #0 \n\t" + #if (uECC_MAX_WORDS != uECC_MIN_WORDS) + "adr %[left], 1f \n\t" + ".align 4 \n\t" + "adds %[jump], %[left] \n\t" + #endif + + "ldmia %[lptr]!, {%[left]} \n\t" + "ldmia %[rptr]!, {%[right]} \n\t" + "subs %[left], %[right] \n\t" + "stmia %[dptr]!, {%[left]} \n\t" + + #if (uECC_MAX_WORDS != uECC_MIN_WORDS) + "bx %[jump] \n\t" + #endif + "1: \n\t" + REPEAT(DEC(uECC_MAX_WORDS), + "ldmia %[lptr]!, {%[left]} \n\t" + "ldmia %[rptr]!, {%[right]} \n\t" + "sbcs %[left], %[right] \n\t" + "stmia %[dptr]!, {%[left]} \n\t") + + "adcs %[carry], %[carry] \n\t" + RESUME_SYNTAX + : [dptr] REG_RW_LO (result), [lptr] REG_RW_LO (left), [rptr] REG_RW_LO (right), + #if (uECC_MAX_WORDS != uECC_MIN_WORDS) + [jump] REG_RW_LO (jump), + #endif + [carry] REG_WRITE_LO (carry), [left] REG_WRITE_LO (left_word), + [right] REG_WRITE_LO (right_word) + : + : "cc", "memory" + ); + return !carry; /* Note that on ARM, carry flag set means "no borrow" when subtracting + (for some reason...) */ +} +#define asm_sub 1 + +#endif /* (uECC_OPTIMIZATION_LEVEL >= 2) */ + +#if (uECC_OPTIMIZATION_LEVEL >= 3) + +#if (uECC_PLATFORM != uECC_arm_thumb) + +#if uECC_ARM_USE_UMAAL + #include "asm_arm_mult_square_umaal.inc" +#else + #include "asm_arm_mult_square.inc" +#endif + +#if (uECC_OPTIMIZATION_LEVEL == 3) + +uECC_VLI_API void uECC_vli_mult(uint32_t *result, + const uint32_t *left, + const uint32_t *right, + wordcount_t num_words) { + register uint32_t *r0 __asm__("r0") = result; + register const uint32_t *r1 __asm__("r1") = left; + register const uint32_t *r2 __asm__("r2") = right; + register uint32_t r3 __asm__("r3") = num_words; + + __asm__ volatile ( + ".syntax unified \n\t" +#if (uECC_MIN_WORDS == 5) + FAST_MULT_ASM_5 + #if (uECC_MAX_WORDS > 5) + FAST_MULT_ASM_5_TO_6 + #endif + #if (uECC_MAX_WORDS > 6) + FAST_MULT_ASM_6_TO_7 + #endif + #if (uECC_MAX_WORDS > 7) + FAST_MULT_ASM_7_TO_8 + #endif +#elif (uECC_MIN_WORDS == 6) + FAST_MULT_ASM_6 + #if (uECC_MAX_WORDS > 6) + FAST_MULT_ASM_6_TO_7 + #endif + #if (uECC_MAX_WORDS > 7) + FAST_MULT_ASM_7_TO_8 + #endif +#elif (uECC_MIN_WORDS == 7) + FAST_MULT_ASM_7 + #if (uECC_MAX_WORDS > 7) + FAST_MULT_ASM_7_TO_8 + #endif +#elif (uECC_MIN_WORDS == 8) + FAST_MULT_ASM_8 +#endif + "1: \n\t" + RESUME_SYNTAX + : "+r" (r0), "+r" (r1), "+r" (r2) + : "r" (r3) + : "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory" + ); +} +#define asm_mult 1 + +#if uECC_SQUARE_FUNC +uECC_VLI_API void uECC_vli_square(uECC_word_t *result, + const uECC_word_t *left, + wordcount_t num_words) { + register uint32_t *r0 __asm__("r0") = result; + register const uint32_t *r1 __asm__("r1") = left; + register uint32_t r2 __asm__("r2") = num_words; + + __asm__ volatile ( + ".syntax unified \n\t" +#if (uECC_MIN_WORDS == 5) + FAST_SQUARE_ASM_5 + #if (uECC_MAX_WORDS > 5) + FAST_SQUARE_ASM_5_TO_6 + #endif + #if (uECC_MAX_WORDS > 6) + FAST_SQUARE_ASM_6_TO_7 + #endif + #if (uECC_MAX_WORDS > 7) + FAST_SQUARE_ASM_7_TO_8 + #endif +#elif (uECC_MIN_WORDS == 6) + FAST_SQUARE_ASM_6 + #if (uECC_MAX_WORDS > 6) + FAST_SQUARE_ASM_6_TO_7 + #endif + #if (uECC_MAX_WORDS > 7) + FAST_SQUARE_ASM_7_TO_8 + #endif +#elif (uECC_MIN_WORDS == 7) + FAST_SQUARE_ASM_7 + #if (uECC_MAX_WORDS > 7) + FAST_SQUARE_ASM_7_TO_8 + #endif +#elif (uECC_MIN_WORDS == 8) + FAST_SQUARE_ASM_8 +#endif + + "1: \n\t" + RESUME_SYNTAX + : "+r" (r0), "+r" (r1) + : "r" (r2) + : "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory" + ); +} +#define asm_square 1 +#endif /* uECC_SQUARE_FUNC */ + +#else /* (uECC_OPTIMIZATION_LEVEL > 3) */ + +uECC_VLI_API void uECC_vli_mult(uint32_t *result, + const uint32_t *left, + const uint32_t *right, + wordcount_t num_words) { + register uint32_t *r0 __asm__("r0") = result; + register const uint32_t *r1 __asm__("r1") = left; + register const uint32_t *r2 __asm__("r2") = right; + register uint32_t r3 __asm__("r3") = num_words; + +#if uECC_SUPPORTS_secp160r1 + if (num_words == 5) { + __asm__ volatile ( + ".syntax unified \n\t" + FAST_MULT_ASM_5 + RESUME_SYNTAX + : "+r" (r0), "+r" (r1), "+r" (r2) + : "r" (r3) + : "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory" + ); + return; + } +#endif +#if uECC_SUPPORTS_secp192r1 + if (num_words == 6) { + __asm__ volatile ( + ".syntax unified \n\t" + FAST_MULT_ASM_6 + RESUME_SYNTAX + : "+r" (r0), "+r" (r1), "+r" (r2) + : "r" (r3) + : "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory" + ); + return; + } +#endif +#if uECC_SUPPORTS_secp224r1 + if (num_words == 7) { + __asm__ volatile ( + ".syntax unified \n\t" + FAST_MULT_ASM_7 + RESUME_SYNTAX + : "+r" (r0), "+r" (r1), "+r" (r2) + : "r" (r3) + : "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory" + ); + return; + } +#endif +#if (uECC_SUPPORTS_secp256r1 || uECC_SUPPORTS_secp256k1) + if (num_words == 8) { + __asm__ volatile ( + ".syntax unified \n\t" + FAST_MULT_ASM_8 + RESUME_SYNTAX + : "+r" (r0), "+r" (r1), "+r" (r2) + : "r" (r3) + : "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory" + ); + return; + } +#endif +} +#define asm_mult 1 + +#if uECC_SQUARE_FUNC +uECC_VLI_API void uECC_vli_square(uECC_word_t *result, + const uECC_word_t *left, + wordcount_t num_words) { + register uint32_t *r0 __asm__("r0") = result; + register const uint32_t *r1 __asm__("r1") = left; + register uint32_t r2 __asm__("r2") = num_words; + +#if uECC_SUPPORTS_secp160r1 + if (num_words == 5) { + __asm__ volatile ( + ".syntax unified \n\t" + FAST_SQUARE_ASM_5 + RESUME_SYNTAX + : "+r" (r0), "+r" (r1) + : "r" (r2) + : "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory" + ); + return; + } +#endif +#if uECC_SUPPORTS_secp192r1 + if (num_words == 6) { + __asm__ volatile ( + ".syntax unified \n\t" + FAST_SQUARE_ASM_6 + RESUME_SYNTAX + : "+r" (r0), "+r" (r1) + : "r" (r2) + : "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory" + ); + return; + } +#endif +#if uECC_SUPPORTS_secp224r1 + if (num_words == 7) { + __asm__ volatile ( + ".syntax unified \n\t" + FAST_SQUARE_ASM_7 + RESUME_SYNTAX + : "+r" (r0), "+r" (r1) + : "r" (r2) + : "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory" + ); + return; + } +#endif +#if (uECC_SUPPORTS_secp256r1 || uECC_SUPPORTS_secp256k1) + if (num_words == 8) { + __asm__ volatile ( + ".syntax unified \n\t" + FAST_SQUARE_ASM_8 + RESUME_SYNTAX + : "+r" (r0), "+r" (r1) + : "r" (r2) + : "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory" + ); + return; + } +#endif +} +#define asm_square 1 +#endif /* uECC_SQUARE_FUNC */ + +#endif /* (uECC_OPTIMIZATION_LEVEL > 3) */ + +#endif /* uECC_PLATFORM != uECC_arm_thumb */ + +#endif /* (uECC_OPTIMIZATION_LEVEL >= 3) */ + +/* ---- "Small" implementations ---- */ + +#if !asm_add +uECC_VLI_API uECC_word_t uECC_vli_add(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + wordcount_t num_words) { + uint32_t carry = 0; + uint32_t left_word; + uint32_t right_word; + + __asm__ volatile ( + ".syntax unified \n\t" + "1: \n\t" + "ldmia %[lptr]!, {%[left]} \n\t" /* Load left word. */ + "ldmia %[rptr]!, {%[right]} \n\t" /* Load right word. */ + "lsrs %[carry], #1 \n\t" /* Set up carry flag (carry = 0 after this). */ + "adcs %[left], %[left], %[right] \n\t" /* Add with carry. */ + "adcs %[carry], %[carry], %[carry] \n\t" /* Store carry bit. */ + "stmia %[dptr]!, {%[left]} \n\t" /* Store result word. */ + "subs %[ctr], #1 \n\t" /* Decrement counter. */ + "bne 1b \n\t" /* Loop until counter == 0. */ + RESUME_SYNTAX + : [dptr] REG_RW (result), [lptr] REG_RW (left), [rptr] REG_RW (right), + [ctr] REG_RW (num_words), [carry] REG_RW (carry), + [left] REG_WRITE (left_word), [right] REG_WRITE (right_word) + : + : "cc", "memory" + ); + return carry; +} +#define asm_add 1 +#endif + +#if !asm_sub +uECC_VLI_API uECC_word_t uECC_vli_sub(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + wordcount_t num_words) { + uint32_t carry = 1; /* carry = 1 initially (means don't borrow) */ + uint32_t left_word; + uint32_t right_word; + + __asm__ volatile ( + ".syntax unified \n\t" + "1: \n\t" + "ldmia %[lptr]!, {%[left]} \n\t" /* Load left word. */ + "ldmia %[rptr]!, {%[right]} \n\t" /* Load right word. */ + "lsrs %[carry], #1 \n\t" /* Set up carry flag (carry = 0 after this). */ + "sbcs %[left], %[left], %[right] \n\t" /* Subtract with borrow. */ + "adcs %[carry], %[carry], %[carry] \n\t" /* Store carry bit. */ + "stmia %[dptr]!, {%[left]} \n\t" /* Store result word. */ + "subs %[ctr], #1 \n\t" /* Decrement counter. */ + "bne 1b \n\t" /* Loop until counter == 0. */ + RESUME_SYNTAX + : [dptr] REG_RW (result), [lptr] REG_RW (left), [rptr] REG_RW (right), + [ctr] REG_RW (num_words), [carry] REG_RW (carry), + [left] REG_WRITE (left_word), [right] REG_WRITE (right_word) + : + : "cc", "memory" + ); + return !carry; +} +#define asm_sub 1 +#endif + +#if !asm_mult +uECC_VLI_API void uECC_vli_mult(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + wordcount_t num_words) { +#if (uECC_PLATFORM != uECC_arm_thumb) + uint32_t c0 = 0; + uint32_t c1 = 0; + uint32_t c2 = 0; + uint32_t k = 0; + uint32_t i; + uint32_t t0, t1; + + __asm__ volatile ( + ".syntax unified \n\t" + + "1: \n\t" /* outer loop (k < num_words) */ + "movs %[i], #0 \n\t" /* i = 0 */ + "b 3f \n\t" + + "2: \n\t" /* outer loop (k >= num_words) */ + "movs %[i], %[k] \n\t" /* i = k */ + "subs %[i], %[last_word] \n\t" /* i = k - (num_words - 1) (times 4) */ + + "3: \n\t" /* inner loop */ + "subs %[t0], %[k], %[i] \n\t" /* t0 = k-i */ + + "ldr %[t1], [%[right], %[t0]] \n\t" /* t1 = right[k - i] */ + "ldr %[t0], [%[left], %[i]] \n\t" /* t0 = left[i] */ + + "umull %[t0], %[t1], %[t0], %[t1] \n\t" /* (t0, t1) = left[i] * right[k - i] */ + + "adds %[c0], %[c0], %[t0] \n\t" /* add low word to c0 */ + "adcs %[c1], %[c1], %[t1] \n\t" /* add high word to c1, including carry */ + "adcs %[c2], %[c2], #0 \n\t" /* add carry to c2 */ + + "adds %[i], #4 \n\t" /* i += 4 */ + "cmp %[i], %[last_word] \n\t" /* i > (num_words - 1) (times 4)? */ + "bgt 4f \n\t" /* if so, exit the loop */ + "cmp %[i], %[k] \n\t" /* i <= k? */ + "ble 3b \n\t" /* if so, continue looping */ + + "4: \n\t" /* end inner loop */ + + "str %[c0], [%[result], %[k]] \n\t" /* result[k] = c0 */ + "mov %[c0], %[c1] \n\t" /* c0 = c1 */ + "mov %[c1], %[c2] \n\t" /* c1 = c2 */ + "movs %[c2], #0 \n\t" /* c2 = 0 */ + "adds %[k], #4 \n\t" /* k += 4 */ + "cmp %[k], %[last_word] \n\t" /* k <= (num_words - 1) (times 4) ? */ + "ble 1b \n\t" /* if so, loop back, start with i = 0 */ + "cmp %[k], %[last_word], lsl #1 \n\t" /* k <= (num_words * 2 - 2) (times 4) ? */ + "ble 2b \n\t" /* if so, loop back, start with i = (k + 1) - num_words */ + /* end outer loop */ + + "str %[c0], [%[result], %[k]] \n\t" /* result[num_words * 2 - 1] = c0 */ + RESUME_SYNTAX + : [c0] "+r" (c0), [c1] "+r" (c1), [c2] "+r" (c2), + [k] "+r" (k), [i] "=&r" (i), [t0] "=&r" (t0), [t1] "=&r" (t1) + : [result] "r" (result), [left] "r" (left), [right] "r" (right), + [last_word] "r" ((num_words - 1) * 4) + : "cc", "memory" + ); + +#else /* Thumb-1 */ + uint32_t r4, r5, r6, r7; + + __asm__ volatile ( + ".syntax unified \n\t" + "subs %[r3], #1 \n\t" /* r3 = num_words - 1 */ + "lsls %[r3], #2 \n\t" /* r3 = (num_words - 1) * 4 */ + "mov r8, %[r3] \n\t" /* r8 = (num_words - 1) * 4 */ + "lsls %[r3], #1 \n\t" /* r3 = (num_words - 1) * 8 */ + "mov r9, %[r3] \n\t" /* r9 = (num_words - 1) * 8 */ + "movs %[r3], #0 \n\t" /* c0 = 0 */ + "movs %[r4], #0 \n\t" /* c1 = 0 */ + "movs %[r5], #0 \n\t" /* c2 = 0 */ + "movs %[r6], #0 \n\t" /* k = 0 */ + + "push {%[r0]} \n\t" /* keep result on the stack */ + + "1: \n\t" /* outer loop (k < num_words) */ + "movs %[r7], #0 \n\t" /* r7 = i = 0 */ + "b 3f \n\t" + + "2: \n\t" /* outer loop (k >= num_words) */ + "movs %[r7], %[r6] \n\t" /* r7 = k */ + "mov %[r0], r8 \n\t" /* r0 = (num_words - 1) * 4 */ + "subs %[r7], %[r0] \n\t" /* r7 = i = k - (num_words - 1) (times 4) */ + + "3: \n\t" /* inner loop */ + "mov r10, %[r3] \n\t" + "mov r11, %[r4] \n\t" + "mov r12, %[r5] \n\t" + "mov r14, %[r6] \n\t" + "subs %[r0], %[r6], %[r7] \n\t" /* r0 = k - i */ + + "ldr %[r4], [%[r2], %[r0]] \n\t" /* r4 = right[k - i] */ + "ldr %[r0], [%[r1], %[r7]] \n\t" /* r0 = left[i] */ + + "lsrs %[r3], %[r0], #16 \n\t" /* r3 = a1 */ + "uxth %[r0], %[r0] \n\t" /* r0 = a0 */ + + "lsrs %[r5], %[r4], #16 \n\t" /* r5 = b1 */ + "uxth %[r4], %[r4] \n\t" /* r4 = b0 */ + + "movs %[r6], %[r3] \n\t" /* r6 = a1 */ + "muls %[r6], %[r5], %[r6] \n\t" /* r6 = a1 * b1 */ + "muls %[r3], %[r4], %[r3] \n\t" /* r3 = b0 * a1 */ + "muls %[r5], %[r0], %[r5] \n\t" /* r5 = a0 * b1 */ + "muls %[r0], %[r4], %[r0] \n\t" /* r0 = a0 * b0 */ + + /* Add middle terms */ + "lsls %[r4], %[r3], #16 \n\t" + "lsrs %[r3], %[r3], #16 \n\t" + "adds %[r0], %[r4] \n\t" + "adcs %[r6], %[r3] \n\t" + + "lsls %[r4], %[r5], #16 \n\t" + "lsrs %[r5], %[r5], #16 \n\t" + "adds %[r0], %[r4] \n\t" + "adcs %[r6], %[r5] \n\t" + + "mov %[r3], r10\n\t" + "mov %[r4], r11\n\t" + "mov %[r5], r12\n\t" + "adds %[r3], %[r0] \n\t" /* add low word to c0 */ + "adcs %[r4], %[r6] \n\t" /* add high word to c1, including carry */ + "movs %[r0], #0 \n\t" /* r0 = 0 (does not affect carry bit) */ + "adcs %[r5], %[r0] \n\t" /* add carry to c2 */ + + "mov %[r6], r14\n\t" /* r6 = k */ + + "adds %[r7], #4 \n\t" /* i += 4 */ + "cmp %[r7], r8 \n\t" /* i > (num_words - 1) (times 4)? */ + "bgt 4f \n\t" /* if so, exit the loop */ + "cmp %[r7], %[r6] \n\t" /* i <= k? */ + "ble 3b \n\t" /* if so, continue looping */ + + "4: \n\t" /* end inner loop */ + + "ldr %[r0], [sp, #0] \n\t" /* r0 = result */ + + "str %[r3], [%[r0], %[r6]] \n\t" /* result[k] = c0 */ + "mov %[r3], %[r4] \n\t" /* c0 = c1 */ + "mov %[r4], %[r5] \n\t" /* c1 = c2 */ + "movs %[r5], #0 \n\t" /* c2 = 0 */ + "adds %[r6], #4 \n\t" /* k += 4 */ + "cmp %[r6], r8 \n\t" /* k <= (num_words - 1) (times 4) ? */ + "ble 1b \n\t" /* if so, loop back, start with i = 0 */ + "cmp %[r6], r9 \n\t" /* k <= (num_words * 2 - 2) (times 4) ? */ + "ble 2b \n\t" /* if so, loop back, with i = (k + 1) - num_words */ + /* end outer loop */ + + "str %[r3], [%[r0], %[r6]] \n\t" /* result[num_words * 2 - 1] = c0 */ + "pop {%[r0]} \n\t" /* pop result off the stack */ + + ".syntax divided \n\t" + : [r3] "+l" (num_words), [r4] "=&l" (r4), + [r5] "=&l" (r5), [r6] "=&l" (r6), [r7] "=&l" (r7) + : [r0] "l" (result), [r1] "l" (left), [r2] "l" (right) + : "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory" + ); +#endif +} +#define asm_mult 1 +#endif + +#if uECC_SQUARE_FUNC +#if !asm_square +uECC_VLI_API void uECC_vli_square(uECC_word_t *result, + const uECC_word_t *left, + wordcount_t num_words) { +#if (uECC_PLATFORM != uECC_arm_thumb) + uint32_t c0 = 0; + uint32_t c1 = 0; + uint32_t c2 = 0; + uint32_t k = 0; + uint32_t i, tt; + uint32_t t0, t1; + + __asm__ volatile ( + ".syntax unified \n\t" + + "1: \n\t" /* outer loop (k < num_words) */ + "movs %[i], #0 \n\t" /* i = 0 */ + "b 3f \n\t" + + "2: \n\t" /* outer loop (k >= num_words) */ + "movs %[i], %[k] \n\t" /* i = k */ + "subs %[i], %[last_word] \n\t" /* i = k - (num_words - 1) (times 4) */ + + "3: \n\t" /* inner loop */ + "subs %[tt], %[k], %[i] \n\t" /* tt = k-i */ + + "ldr %[t1], [%[left], %[tt]] \n\t" /* t1 = left[k - i] */ + "ldr %[t0], [%[left], %[i]] \n\t" /* t0 = left[i] */ + + "umull %[t0], %[t1], %[t0], %[t1] \n\t" /* (t0, t1) = left[i] * right[k - i] */ + + "cmp %[i], %[tt] \n\t" /* (i < k - i) ? */ + "bge 4f \n\t" /* if i >= k - i, skip */ + "adds %[c0], %[c0], %[t0] \n\t" /* add low word to c0 */ + "adcs %[c1], %[c1], %[t1] \n\t" /* add high word to c1, including carry */ + "adcs %[c2], %[c2], #0 \n\t" /* add carry to c2 */ + + "4: \n\t" + "adds %[c0], %[c0], %[t0] \n\t" /* add low word to c0 */ + "adcs %[c1], %[c1], %[t1] \n\t" /* add high word to c1, including carry */ + "adcs %[c2], %[c2], #0 \n\t" /* add carry to c2 */ + + "adds %[i], #4 \n\t" /* i += 4 */ + "cmp %[i], %[k] \n\t" /* i >= k? */ + "bge 5f \n\t" /* if so, exit the loop */ + "subs %[tt], %[k], %[i] \n\t" /* tt = k - i */ + "cmp %[i], %[tt] \n\t" /* i <= k - i? */ + "ble 3b \n\t" /* if so, continue looping */ + + "5: \n\t" /* end inner loop */ + + "str %[c0], [%[result], %[k]] \n\t" /* result[k] = c0 */ + "mov %[c0], %[c1] \n\t" /* c0 = c1 */ + "mov %[c1], %[c2] \n\t" /* c1 = c2 */ + "movs %[c2], #0 \n\t" /* c2 = 0 */ + "adds %[k], #4 \n\t" /* k += 4 */ + "cmp %[k], %[last_word] \n\t" /* k <= (num_words - 1) (times 4) ? */ + "ble 1b \n\t" /* if so, loop back, start with i = 0 */ + "cmp %[k], %[last_word], lsl #1 \n\t" /* k <= (num_words * 2 - 2) (times 4) ? */ + "ble 2b \n\t" /* if so, loop back, start with i = (k + 1) - num_words */ + /* end outer loop */ + + "str %[c0], [%[result], %[k]] \n\t" /* result[num_words * 2 - 1] = c0 */ + RESUME_SYNTAX + : [c0] "+r" (c0), [c1] "+r" (c1), [c2] "+r" (c2), + [k] "+r" (k), [i] "=&r" (i), [tt] "=&r" (tt), [t0] "=&r" (t0), [t1] "=&r" (t1) + : [result] "r" (result), [left] "r" (left), [last_word] "r" ((num_words - 1) * 4) + : "cc", "memory" + ); + +#else + uint32_t r3, r4, r5, r6, r7; + + __asm__ volatile ( + ".syntax unified \n\t" + "subs %[r2], #1 \n\t" /* r2 = num_words - 1 */ + "lsls %[r2], #2 \n\t" /* r2 = (num_words - 1) * 4 */ + "mov r8, %[r2] \n\t" /* r8 = (num_words - 1) * 4 */ + "lsls %[r2], #1 \n\t" /* r2 = (num_words - 1) * 8 */ + "mov r9, %[r2] \n\t" /* r9 = (num_words - 1) * 8 */ + "movs %[r2], #0 \n\t" /* c0 = 0 */ + "movs %[r3], #0 \n\t" /* c1 = 0 */ + "movs %[r4], #0 \n\t" /* c2 = 0 */ + "movs %[r5], #0 \n\t" /* k = 0 */ + + "push {%[r0]} \n\t" /* keep result on the stack */ + + "1: \n\t" /* outer loop (k < num_words) */ + "movs %[r6], #0 \n\t" /* r6 = i = 0 */ + "b 3f \n\t" + + "2: \n\t" /* outer loop (k >= num_words) */ + "movs %[r6], %[r5] \n\t" /* r6 = k */ + "mov %[r0], r8 \n\t" /* r0 = (num_words - 1) * 4 */ + "subs %[r6], %[r0] \n\t" /* r6 = i = k - (num_words - 1) (times 4) */ + + "3: \n\t" /* inner loop */ + "mov r10, %[r2] \n\t" + "mov r11, %[r3] \n\t" + "mov r12, %[r4] \n\t" + "mov r14, %[r5] \n\t" + "subs %[r7], %[r5], %[r6] \n\t" /* r7 = k - i */ + + "ldr %[r3], [%[r1], %[r7]] \n\t" /* r3 = left[k - i] */ + "ldr %[r0], [%[r1], %[r6]] \n\t" /* r0 = left[i] */ + + "lsrs %[r2], %[r0], #16 \n\t" /* r2 = a1 */ + "uxth %[r0], %[r0] \n\t" /* r0 = a0 */ + + "lsrs %[r4], %[r3], #16 \n\t" /* r4 = b1 */ + "uxth %[r3], %[r3] \n\t" /* r3 = b0 */ + + "movs %[r5], %[r2] \n\t" /* r5 = a1 */ + "muls %[r5], %[r4], %[r5] \n\t" /* r5 = a1 * b1 */ + "muls %[r2], %[r3], %[r2] \n\t" /* r2 = b0 * a1 */ + "muls %[r4], %[r0], %[r4] \n\t" /* r4 = a0 * b1 */ + "muls %[r0], %[r3], %[r0] \n\t" /* r0 = a0 * b0 */ + + /* Add middle terms */ + "lsls %[r3], %[r2], #16 \n\t" + "lsrs %[r2], %[r2], #16 \n\t" + "adds %[r0], %[r3] \n\t" + "adcs %[r5], %[r2] \n\t" + + "lsls %[r3], %[r4], #16 \n\t" + "lsrs %[r4], %[r4], #16 \n\t" + "adds %[r0], %[r3] \n\t" + "adcs %[r5], %[r4] \n\t" + + /* Add to acc, doubling if necessary */ + "mov %[r2], r10\n\t" + "mov %[r3], r11\n\t" + "mov %[r4], r12\n\t" + + "cmp %[r6], %[r7] \n\t" /* (i < k - i) ? */ + "bge 4f \n\t" /* if i >= k - i, skip */ + "movs %[r7], #0 \n\t" /* r7 = 0 */ + "adds %[r2], %[r0] \n\t" /* add low word to c0 */ + "adcs %[r3], %[r5] \n\t" /* add high word to c1, including carry */ + "adcs %[r4], %[r7] \n\t" /* add carry to c2 */ + "4: \n\t" + "movs %[r7], #0 \n\t" /* r7 = 0 */ + "adds %[r2], %[r0] \n\t" /* add low word to c0 */ + "adcs %[r3], %[r5] \n\t" /* add high word to c1, including carry */ + "adcs %[r4], %[r7] \n\t" /* add carry to c2 */ + + "mov %[r5], r14\n\t" /* r5 = k */ + + "adds %[r6], #4 \n\t" /* i += 4 */ + "cmp %[r6], %[r5] \n\t" /* i >= k? */ + "bge 5f \n\t" /* if so, exit the loop */ + "subs %[r7], %[r5], %[r6] \n\t" /* r7 = k - i */ + "cmp %[r6], %[r7] \n\t" /* i <= k - i? */ + "ble 3b \n\t" /* if so, continue looping */ + + "5: \n\t" /* end inner loop */ + + "ldr %[r0], [sp, #0] \n\t" /* r0 = result */ + + "str %[r2], [%[r0], %[r5]] \n\t" /* result[k] = c0 */ + "mov %[r2], %[r3] \n\t" /* c0 = c1 */ + "mov %[r3], %[r4] \n\t" /* c1 = c2 */ + "movs %[r4], #0 \n\t" /* c2 = 0 */ + "adds %[r5], #4 \n\t" /* k += 4 */ + "cmp %[r5], r8 \n\t" /* k <= (num_words - 1) (times 4) ? */ + "ble 1b \n\t" /* if so, loop back, start with i = 0 */ + "cmp %[r5], r9 \n\t" /* k <= (num_words * 2 - 2) (times 4) ? */ + "ble 2b \n\t" /* if so, loop back, with i = (k + 1) - num_words */ + /* end outer loop */ + + "str %[r2], [%[r0], %[r5]] \n\t" /* result[num_words * 2 - 1] = c0 */ + "pop {%[r0]} \n\t" /* pop result off the stack */ + + ".syntax divided \n\t" + : [r2] "+l" (num_words), [r3] "=&l" (r3), [r4] "=&l" (r4), + [r5] "=&l" (r5), [r6] "=&l" (r6), [r7] "=&l" (r7) + : [r0] "l" (result), [r1] "l" (left) + : "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory" + ); +#endif +} +#define asm_square 1 +#endif +#endif /* uECC_SQUARE_FUNC */ + +#endif /* _UECC_ASM_ARM_H_ */
diff -r 000000000000 -r b6fdeddc0bc9 curve-specific.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/curve-specific.h Thu Sep 07 12:10:11 2017 +0000 @@ -0,0 +1,1248 @@ +/* Copyright 2015, Kenneth MacKay. Licensed under the BSD 2-clause license. */ + +#ifndef _UECC_CURVE_SPECIFIC_H_ +#define _UECC_CURVE_SPECIFIC_H_ + +#define num_bytes_secp160r1 20 +#define num_bytes_secp192r1 24 +#define num_bytes_secp224r1 28 +#define num_bytes_secp256r1 32 +#define num_bytes_secp256k1 32 + +#if (uECC_WORD_SIZE == 1) + +#define num_words_secp160r1 20 +#define num_words_secp192r1 24 +#define num_words_secp224r1 28 +#define num_words_secp256r1 32 +#define num_words_secp256k1 32 + +#define BYTES_TO_WORDS_8(a, b, c, d, e, f, g, h) \ + 0x##a, 0x##b, 0x##c, 0x##d, 0x##e, 0x##f, 0x##g, 0x##h +#define BYTES_TO_WORDS_4(a, b, c, d) 0x##a, 0x##b, 0x##c, 0x##d + +#elif (uECC_WORD_SIZE == 4) + +#define num_words_secp160r1 5 +#define num_words_secp192r1 6 +#define num_words_secp224r1 7 +#define num_words_secp256r1 8 +#define num_words_secp256k1 8 + +#define BYTES_TO_WORDS_8(a, b, c, d, e, f, g, h) 0x##d##c##b##a, 0x##h##g##f##e +#define BYTES_TO_WORDS_4(a, b, c, d) 0x##d##c##b##a + +#elif (uECC_WORD_SIZE == 8) + +#define num_words_secp160r1 3 +#define num_words_secp192r1 3 +#define num_words_secp224r1 4 +#define num_words_secp256r1 4 +#define num_words_secp256k1 4 + +#define BYTES_TO_WORDS_8(a, b, c, d, e, f, g, h) 0x##h##g##f##e##d##c##b##a##ull +#define BYTES_TO_WORDS_4(a, b, c, d) 0x##d##c##b##a##ull + +#endif /* uECC_WORD_SIZE */ + +#if uECC_SUPPORTS_secp160r1 || uECC_SUPPORTS_secp192r1 || \ + uECC_SUPPORTS_secp224r1 || uECC_SUPPORTS_secp256r1 +static void double_jacobian_default(uECC_word_t * X1, + uECC_word_t * Y1, + uECC_word_t * Z1, + uECC_Curve curve) { + /* t1 = X, t2 = Y, t3 = Z */ + uECC_word_t t4[uECC_MAX_WORDS]; + uECC_word_t t5[uECC_MAX_WORDS]; + wordcount_t num_words = curve->num_words; + + if (uECC_vli_isZero(Z1, num_words)) { + return; + } + + uECC_vli_modSquare_fast(t4, Y1, curve); /* t4 = y1^2 */ + uECC_vli_modMult_fast(t5, X1, t4, curve); /* t5 = x1*y1^2 = A */ + uECC_vli_modSquare_fast(t4, t4, curve); /* t4 = y1^4 */ + uECC_vli_modMult_fast(Y1, Y1, Z1, curve); /* t2 = y1*z1 = z3 */ + uECC_vli_modSquare_fast(Z1, Z1, curve); /* t3 = z1^2 */ + + uECC_vli_modAdd(X1, X1, Z1, curve->p, num_words); /* t1 = x1 + z1^2 */ + uECC_vli_modAdd(Z1, Z1, Z1, curve->p, num_words); /* t3 = 2*z1^2 */ + uECC_vli_modSub(Z1, X1, Z1, curve->p, num_words); /* t3 = x1 - z1^2 */ + uECC_vli_modMult_fast(X1, X1, Z1, curve); /* t1 = x1^2 - z1^4 */ + + uECC_vli_modAdd(Z1, X1, X1, curve->p, num_words); /* t3 = 2*(x1^2 - z1^4) */ + uECC_vli_modAdd(X1, X1, Z1, curve->p, num_words); /* t1 = 3*(x1^2 - z1^4) */ + if (uECC_vli_testBit(X1, 0)) { + uECC_word_t l_carry = uECC_vli_add(X1, X1, curve->p, num_words); + uECC_vli_rshift1(X1, num_words); + X1[num_words - 1] |= l_carry << (uECC_WORD_BITS - 1); + } else { + uECC_vli_rshift1(X1, num_words); + } + /* t1 = 3/2*(x1^2 - z1^4) = B */ + + uECC_vli_modSquare_fast(Z1, X1, curve); /* t3 = B^2 */ + uECC_vli_modSub(Z1, Z1, t5, curve->p, num_words); /* t3 = B^2 - A */ + uECC_vli_modSub(Z1, Z1, t5, curve->p, num_words); /* t3 = B^2 - 2A = x3 */ + uECC_vli_modSub(t5, t5, Z1, curve->p, num_words); /* t5 = A - x3 */ + uECC_vli_modMult_fast(X1, X1, t5, curve); /* t1 = B * (A - x3) */ + uECC_vli_modSub(t4, X1, t4, curve->p, num_words); /* t4 = B * (A - x3) - y1^4 = y3 */ + + uECC_vli_set(X1, Z1, num_words); + uECC_vli_set(Z1, Y1, num_words); + uECC_vli_set(Y1, t4, num_words); +} + +/* Computes result = x^3 + ax + b. result must not overlap x. */ +static void x_side_default(uECC_word_t *result, const uECC_word_t *x, uECC_Curve curve) { + uECC_word_t _3[uECC_MAX_WORDS] = {3}; /* -a = 3 */ + wordcount_t num_words = curve->num_words; + + uECC_vli_modSquare_fast(result, x, curve); /* r = x^2 */ + uECC_vli_modSub(result, result, _3, curve->p, num_words); /* r = x^2 - 3 */ + uECC_vli_modMult_fast(result, result, x, curve); /* r = x^3 - 3x */ + uECC_vli_modAdd(result, result, curve->b, curve->p, num_words); /* r = x^3 - 3x + b */ +} +#endif /* uECC_SUPPORTS_secp... */ + +#if uECC_SUPPORT_COMPRESSED_POINT +#if uECC_SUPPORTS_secp160r1 || uECC_SUPPORTS_secp192r1 || \ + uECC_SUPPORTS_secp256r1 || uECC_SUPPORTS_secp256k1 +/* Compute a = sqrt(a) (mod curve_p). */ +static void mod_sqrt_default(uECC_word_t *a, uECC_Curve curve) { + bitcount_t i; + uECC_word_t p1[uECC_MAX_WORDS] = {1}; + uECC_word_t l_result[uECC_MAX_WORDS] = {1}; + wordcount_t num_words = curve->num_words; + + /* When curve->p == 3 (mod 4), we can compute + sqrt(a) = a^((curve->p + 1) / 4) (mod curve->p). */ + uECC_vli_add(p1, curve->p, p1, num_words); /* p1 = curve_p + 1 */ + for (i = uECC_vli_numBits(p1, num_words) - 1; i > 1; --i) { + uECC_vli_modSquare_fast(l_result, l_result, curve); + if (uECC_vli_testBit(p1, i)) { + uECC_vli_modMult_fast(l_result, l_result, a, curve); + } + } + uECC_vli_set(a, l_result, num_words); +} +#endif /* uECC_SUPPORTS_secp... */ +#endif /* uECC_SUPPORT_COMPRESSED_POINT */ + +#if uECC_SUPPORTS_secp160r1 + +#if (uECC_OPTIMIZATION_LEVEL > 0) +static void vli_mmod_fast_secp160r1(uECC_word_t *result, uECC_word_t *product); +#endif + +static const struct uECC_Curve_t curve_secp160r1 = { + num_words_secp160r1, + num_bytes_secp160r1, + 161, /* num_n_bits */ + { BYTES_TO_WORDS_8(FF, FF, FF, 7F, FF, FF, FF, FF), + BYTES_TO_WORDS_8(FF, FF, FF, FF, FF, FF, FF, FF), + BYTES_TO_WORDS_4(FF, FF, FF, FF) }, + { BYTES_TO_WORDS_8(57, 22, 75, CA, D3, AE, 27, F9), + BYTES_TO_WORDS_8(C8, F4, 01, 00, 00, 00, 00, 00), + BYTES_TO_WORDS_8(00, 00, 00, 00, 01, 00, 00, 00) }, + { BYTES_TO_WORDS_8(82, FC, CB, 13, B9, 8B, C3, 68), + BYTES_TO_WORDS_8(89, 69, 64, 46, 28, 73, F5, 8E), + BYTES_TO_WORDS_4(68, B5, 96, 4A), + + BYTES_TO_WORDS_8(32, FB, C5, 7A, 37, 51, 23, 04), + BYTES_TO_WORDS_8(12, C9, DC, 59, 7D, 94, 68, 31), + BYTES_TO_WORDS_4(55, 28, A6, 23) }, + { BYTES_TO_WORDS_8(45, FA, 65, C5, AD, D4, D4, 81), + BYTES_TO_WORDS_8(9F, F8, AC, 65, 8B, 7A, BD, 54), + BYTES_TO_WORDS_4(FC, BE, 97, 1C) }, + &double_jacobian_default, +#if uECC_SUPPORT_COMPRESSED_POINT + &mod_sqrt_default, +#endif + &x_side_default, +#if (uECC_OPTIMIZATION_LEVEL > 0) + &vli_mmod_fast_secp160r1 +#endif +}; + +uECC_Curve uECC_secp160r1(void) { return &curve_secp160r1; } + +#if (uECC_OPTIMIZATION_LEVEL > 0 && !asm_mmod_fast_secp160r1) +/* Computes result = product % curve_p + see http://www.isys.uni-klu.ac.at/PDF/2001-0126-MT.pdf page 354 + + Note that this only works if log2(omega) < log2(p) / 2 */ +static void omega_mult_secp160r1(uECC_word_t *result, const uECC_word_t *right); +#if uECC_WORD_SIZE == 8 +static void vli_mmod_fast_secp160r1(uECC_word_t *result, uECC_word_t *product) { + uECC_word_t tmp[2 * num_words_secp160r1]; + uECC_word_t copy; + + uECC_vli_clear(tmp, num_words_secp160r1); + uECC_vli_clear(tmp + num_words_secp160r1, num_words_secp160r1); + + omega_mult_secp160r1(tmp, product + num_words_secp160r1 - 1); /* (Rq, q) = q * c */ + + product[num_words_secp160r1 - 1] &= 0xffffffff; + copy = tmp[num_words_secp160r1 - 1]; + tmp[num_words_secp160r1 - 1] &= 0xffffffff; + uECC_vli_add(result, product, tmp, num_words_secp160r1); /* (C, r) = r + q */ + uECC_vli_clear(product, num_words_secp160r1); + tmp[num_words_secp160r1 - 1] = copy; + omega_mult_secp160r1(product, tmp + num_words_secp160r1 - 1); /* Rq*c */ + uECC_vli_add(result, result, product, num_words_secp160r1); /* (C1, r) = r + Rq*c */ + + while (uECC_vli_cmp_unsafe(result, curve_secp160r1.p, num_words_secp160r1) > 0) { + uECC_vli_sub(result, result, curve_secp160r1.p, num_words_secp160r1); + } +} + +static void omega_mult_secp160r1(uint64_t *result, const uint64_t *right) { + uint32_t carry; + unsigned i; + + /* Multiply by (2^31 + 1). */ + carry = 0; + for (i = 0; i < num_words_secp160r1; ++i) { + uint64_t tmp = (right[i] >> 32) | (right[i + 1] << 32); + result[i] = (tmp << 31) + tmp + carry; + carry = (tmp >> 33) + (result[i] < tmp || (carry && result[i] == tmp)); + } + result[i] = carry; +} +#else +static void vli_mmod_fast_secp160r1(uECC_word_t *result, uECC_word_t *product) { + uECC_word_t tmp[2 * num_words_secp160r1]; + uECC_word_t carry; + + uECC_vli_clear(tmp, num_words_secp160r1); + uECC_vli_clear(tmp + num_words_secp160r1, num_words_secp160r1); + + omega_mult_secp160r1(tmp, product + num_words_secp160r1); /* (Rq, q) = q * c */ + + carry = uECC_vli_add(result, product, tmp, num_words_secp160r1); /* (C, r) = r + q */ + uECC_vli_clear(product, num_words_secp160r1); + omega_mult_secp160r1(product, tmp + num_words_secp160r1); /* Rq*c */ + carry += uECC_vli_add(result, result, product, num_words_secp160r1); /* (C1, r) = r + Rq*c */ + + while (carry > 0) { + --carry; + uECC_vli_sub(result, result, curve_secp160r1.p, num_words_secp160r1); + } + if (uECC_vli_cmp_unsafe(result, curve_secp160r1.p, num_words_secp160r1) > 0) { + uECC_vli_sub(result, result, curve_secp160r1.p, num_words_secp160r1); + } +} +#endif + +#if uECC_WORD_SIZE == 1 +static void omega_mult_secp160r1(uint8_t *result, const uint8_t *right) { + uint8_t carry; + uint8_t i; + + /* Multiply by (2^31 + 1). */ + uECC_vli_set(result + 4, right, num_words_secp160r1); /* 2^32 */ + uECC_vli_rshift1(result + 4, num_words_secp160r1); /* 2^31 */ + result[3] = right[0] << 7; /* get last bit from shift */ + + carry = uECC_vli_add(result, result, right, num_words_secp160r1); /* 2^31 + 1 */ + for (i = num_words_secp160r1; carry; ++i) { + uint16_t sum = (uint16_t)result[i] + carry; + result[i] = (uint8_t)sum; + carry = sum >> 8; + } +} +#elif uECC_WORD_SIZE == 4 +static void omega_mult_secp160r1(uint32_t *result, const uint32_t *right) { + uint32_t carry; + unsigned i; + + /* Multiply by (2^31 + 1). */ + uECC_vli_set(result + 1, right, num_words_secp160r1); /* 2^32 */ + uECC_vli_rshift1(result + 1, num_words_secp160r1); /* 2^31 */ + result[0] = right[0] << 31; /* get last bit from shift */ + + carry = uECC_vli_add(result, result, right, num_words_secp160r1); /* 2^31 + 1 */ + for (i = num_words_secp160r1; carry; ++i) { + uint64_t sum = (uint64_t)result[i] + carry; + result[i] = (uint32_t)sum; + carry = sum >> 32; + } +} +#endif /* uECC_WORD_SIZE */ +#endif /* (uECC_OPTIMIZATION_LEVEL > 0 && !asm_mmod_fast_secp160r1) */ + +#endif /* uECC_SUPPORTS_secp160r1 */ + +#if uECC_SUPPORTS_secp192r1 + +#if (uECC_OPTIMIZATION_LEVEL > 0) +static void vli_mmod_fast_secp192r1(uECC_word_t *result, uECC_word_t *product); +#endif + +static const struct uECC_Curve_t curve_secp192r1 = { + num_words_secp192r1, + num_bytes_secp192r1, + 192, /* num_n_bits */ + { BYTES_TO_WORDS_8(FF, FF, FF, FF, FF, FF, FF, FF), + BYTES_TO_WORDS_8(FE, FF, FF, FF, FF, FF, FF, FF), + BYTES_TO_WORDS_8(FF, FF, FF, FF, FF, FF, FF, FF) }, + { BYTES_TO_WORDS_8(31, 28, D2, B4, B1, C9, 6B, 14), + BYTES_TO_WORDS_8(36, F8, DE, 99, FF, FF, FF, FF), + BYTES_TO_WORDS_8(FF, FF, FF, FF, FF, FF, FF, FF) }, + { BYTES_TO_WORDS_8(12, 10, FF, 82, FD, 0A, FF, F4), + BYTES_TO_WORDS_8(00, 88, A1, 43, EB, 20, BF, 7C), + BYTES_TO_WORDS_8(F6, 90, 30, B0, 0E, A8, 8D, 18), + + BYTES_TO_WORDS_8(11, 48, 79, 1E, A1, 77, F9, 73), + BYTES_TO_WORDS_8(D5, CD, 24, 6B, ED, 11, 10, 63), + BYTES_TO_WORDS_8(78, DA, C8, FF, 95, 2B, 19, 07) }, + { BYTES_TO_WORDS_8(B1, B9, 46, C1, EC, DE, B8, FE), + BYTES_TO_WORDS_8(49, 30, 24, 72, AB, E9, A7, 0F), + BYTES_TO_WORDS_8(E7, 80, 9C, E5, 19, 05, 21, 64) }, + &double_jacobian_default, +#if uECC_SUPPORT_COMPRESSED_POINT + &mod_sqrt_default, +#endif + &x_side_default, +#if (uECC_OPTIMIZATION_LEVEL > 0) + &vli_mmod_fast_secp192r1 +#endif +}; + +uECC_Curve uECC_secp192r1(void) { return &curve_secp192r1; } + +#if (uECC_OPTIMIZATION_LEVEL > 0) +/* Computes result = product % curve_p. + See algorithm 5 and 6 from http://www.isys.uni-klu.ac.at/PDF/2001-0126-MT.pdf */ +#if uECC_WORD_SIZE == 1 +static void vli_mmod_fast_secp192r1(uint8_t *result, uint8_t *product) { + uint8_t tmp[num_words_secp192r1]; + uint8_t carry; + + uECC_vli_set(result, product, num_words_secp192r1); + + uECC_vli_set(tmp, &product[24], num_words_secp192r1); + carry = uECC_vli_add(result, result, tmp, num_words_secp192r1); + + tmp[0] = tmp[1] = tmp[2] = tmp[3] = tmp[4] = tmp[5] = tmp[6] = tmp[7] = 0; + tmp[8] = product[24]; tmp[9] = product[25]; tmp[10] = product[26]; tmp[11] = product[27]; + tmp[12] = product[28]; tmp[13] = product[29]; tmp[14] = product[30]; tmp[15] = product[31]; + tmp[16] = product[32]; tmp[17] = product[33]; tmp[18] = product[34]; tmp[19] = product[35]; + tmp[20] = product[36]; tmp[21] = product[37]; tmp[22] = product[38]; tmp[23] = product[39]; + carry += uECC_vli_add(result, result, tmp, num_words_secp192r1); + + tmp[0] = tmp[8] = product[40]; + tmp[1] = tmp[9] = product[41]; + tmp[2] = tmp[10] = product[42]; + tmp[3] = tmp[11] = product[43]; + tmp[4] = tmp[12] = product[44]; + tmp[5] = tmp[13] = product[45]; + tmp[6] = tmp[14] = product[46]; + tmp[7] = tmp[15] = product[47]; + tmp[16] = tmp[17] = tmp[18] = tmp[19] = tmp[20] = tmp[21] = tmp[22] = tmp[23] = 0; + carry += uECC_vli_add(result, result, tmp, num_words_secp192r1); + + while (carry || uECC_vli_cmp_unsafe(curve_secp192r1.p, result, num_words_secp192r1) != 1) { + carry -= uECC_vli_sub(result, result, curve_secp192r1.p, num_words_secp192r1); + } +} +#elif uECC_WORD_SIZE == 4 +static void vli_mmod_fast_secp192r1(uint32_t *result, uint32_t *product) { + uint32_t tmp[num_words_secp192r1]; + int carry; + + uECC_vli_set(result, product, num_words_secp192r1); + + uECC_vli_set(tmp, &product[6], num_words_secp192r1); + carry = uECC_vli_add(result, result, tmp, num_words_secp192r1); + + tmp[0] = tmp[1] = 0; + tmp[2] = product[6]; + tmp[3] = product[7]; + tmp[4] = product[8]; + tmp[5] = product[9]; + carry += uECC_vli_add(result, result, tmp, num_words_secp192r1); + + tmp[0] = tmp[2] = product[10]; + tmp[1] = tmp[3] = product[11]; + tmp[4] = tmp[5] = 0; + carry += uECC_vli_add(result, result, tmp, num_words_secp192r1); + + while (carry || uECC_vli_cmp_unsafe(curve_secp192r1.p, result, num_words_secp192r1) != 1) { + carry -= uECC_vli_sub(result, result, curve_secp192r1.p, num_words_secp192r1); + } +} +#else +static void vli_mmod_fast_secp192r1(uint64_t *result, uint64_t *product) { + uint64_t tmp[num_words_secp192r1]; + int carry; + + uECC_vli_set(result, product, num_words_secp192r1); + + uECC_vli_set(tmp, &product[3], num_words_secp192r1); + carry = (int)uECC_vli_add(result, result, tmp, num_words_secp192r1); + + tmp[0] = 0; + tmp[1] = product[3]; + tmp[2] = product[4]; + carry += uECC_vli_add(result, result, tmp, num_words_secp192r1); + + tmp[0] = tmp[1] = product[5]; + tmp[2] = 0; + carry += uECC_vli_add(result, result, tmp, num_words_secp192r1); + + while (carry || uECC_vli_cmp_unsafe(curve_secp192r1.p, result, num_words_secp192r1) != 1) { + carry -= uECC_vli_sub(result, result, curve_secp192r1.p, num_words_secp192r1); + } +} +#endif /* uECC_WORD_SIZE */ +#endif /* (uECC_OPTIMIZATION_LEVEL > 0) */ + +#endif /* uECC_SUPPORTS_secp192r1 */ + +#if uECC_SUPPORTS_secp224r1 + +#if uECC_SUPPORT_COMPRESSED_POINT +static void mod_sqrt_secp224r1(uECC_word_t *a, uECC_Curve curve); +#endif +#if (uECC_OPTIMIZATION_LEVEL > 0) +static void vli_mmod_fast_secp224r1(uECC_word_t *result, uECC_word_t *product); +#endif + +static const struct uECC_Curve_t curve_secp224r1 = { + num_words_secp224r1, + num_bytes_secp224r1, + 224, /* num_n_bits */ + { BYTES_TO_WORDS_8(01, 00, 00, 00, 00, 00, 00, 00), + BYTES_TO_WORDS_8(00, 00, 00, 00, FF, FF, FF, FF), + BYTES_TO_WORDS_8(FF, FF, FF, FF, FF, FF, FF, FF), + BYTES_TO_WORDS_4(FF, FF, FF, FF) }, + { BYTES_TO_WORDS_8(3D, 2A, 5C, 5C, 45, 29, DD, 13), + BYTES_TO_WORDS_8(3E, F0, B8, E0, A2, 16, FF, FF), + BYTES_TO_WORDS_8(FF, FF, FF, FF, FF, FF, FF, FF), + BYTES_TO_WORDS_4(FF, FF, FF, FF) }, + { BYTES_TO_WORDS_8(21, 1D, 5C, 11, D6, 80, 32, 34), + BYTES_TO_WORDS_8(22, 11, C2, 56, D3, C1, 03, 4A), + BYTES_TO_WORDS_8(B9, 90, 13, 32, 7F, BF, B4, 6B), + BYTES_TO_WORDS_4(BD, 0C, 0E, B7), + + BYTES_TO_WORDS_8(34, 7E, 00, 85, 99, 81, D5, 44), + BYTES_TO_WORDS_8(64, 47, 07, 5A, A0, 75, 43, CD), + BYTES_TO_WORDS_8(E6, DF, 22, 4C, FB, 23, F7, B5), + BYTES_TO_WORDS_4(88, 63, 37, BD) }, + { BYTES_TO_WORDS_8(B4, FF, 55, 23, 43, 39, 0B, 27), + BYTES_TO_WORDS_8(BA, D8, BF, D7, B7, B0, 44, 50), + BYTES_TO_WORDS_8(56, 32, 41, F5, AB, B3, 04, 0C), + BYTES_TO_WORDS_4(85, 0A, 05, B4) }, + &double_jacobian_default, +#if uECC_SUPPORT_COMPRESSED_POINT + &mod_sqrt_secp224r1, +#endif + &x_side_default, +#if (uECC_OPTIMIZATION_LEVEL > 0) + &vli_mmod_fast_secp224r1 +#endif +}; + +uECC_Curve uECC_secp224r1(void) { return &curve_secp224r1; } + + +#if uECC_SUPPORT_COMPRESSED_POINT +/* Routine 3.2.4 RS; from http://www.nsa.gov/ia/_files/nist-routines.pdf */ +static void mod_sqrt_secp224r1_rs(uECC_word_t *d1, + uECC_word_t *e1, + uECC_word_t *f1, + const uECC_word_t *d0, + const uECC_word_t *e0, + const uECC_word_t *f0) { + uECC_word_t t[num_words_secp224r1]; + + uECC_vli_modSquare_fast(t, d0, &curve_secp224r1); /* t <-- d0 ^ 2 */ + uECC_vli_modMult_fast(e1, d0, e0, &curve_secp224r1); /* e1 <-- d0 * e0 */ + uECC_vli_modAdd(d1, t, f0, curve_secp224r1.p, num_words_secp224r1); /* d1 <-- t + f0 */ + uECC_vli_modAdd(e1, e1, e1, curve_secp224r1.p, num_words_secp224r1); /* e1 <-- e1 + e1 */ + uECC_vli_modMult_fast(f1, t, f0, &curve_secp224r1); /* f1 <-- t * f0 */ + uECC_vli_modAdd(f1, f1, f1, curve_secp224r1.p, num_words_secp224r1); /* f1 <-- f1 + f1 */ + uECC_vli_modAdd(f1, f1, f1, curve_secp224r1.p, num_words_secp224r1); /* f1 <-- f1 + f1 */ +} + +/* Routine 3.2.5 RSS; from http://www.nsa.gov/ia/_files/nist-routines.pdf */ +static void mod_sqrt_secp224r1_rss(uECC_word_t *d1, + uECC_word_t *e1, + uECC_word_t *f1, + const uECC_word_t *d0, + const uECC_word_t *e0, + const uECC_word_t *f0, + const bitcount_t j) { + bitcount_t i; + + uECC_vli_set(d1, d0, num_words_secp224r1); /* d1 <-- d0 */ + uECC_vli_set(e1, e0, num_words_secp224r1); /* e1 <-- e0 */ + uECC_vli_set(f1, f0, num_words_secp224r1); /* f1 <-- f0 */ + for (i = 1; i <= j; i++) { + mod_sqrt_secp224r1_rs(d1, e1, f1, d1, e1, f1); /* RS (d1,e1,f1,d1,e1,f1) */ + } +} + +/* Routine 3.2.6 RM; from http://www.nsa.gov/ia/_files/nist-routines.pdf */ +static void mod_sqrt_secp224r1_rm(uECC_word_t *d2, + uECC_word_t *e2, + uECC_word_t *f2, + const uECC_word_t *c, + const uECC_word_t *d0, + const uECC_word_t *e0, + const uECC_word_t *d1, + const uECC_word_t *e1) { + uECC_word_t t1[num_words_secp224r1]; + uECC_word_t t2[num_words_secp224r1]; + + uECC_vli_modMult_fast(t1, e0, e1, &curve_secp224r1); /* t1 <-- e0 * e1 */ + uECC_vli_modMult_fast(t1, t1, c, &curve_secp224r1); /* t1 <-- t1 * c */ + /* t1 <-- p - t1 */ + uECC_vli_modSub(t1, curve_secp224r1.p, t1, curve_secp224r1.p, num_words_secp224r1); + uECC_vli_modMult_fast(t2, d0, d1, &curve_secp224r1); /* t2 <-- d0 * d1 */ + uECC_vli_modAdd(t2, t2, t1, curve_secp224r1.p, num_words_secp224r1); /* t2 <-- t2 + t1 */ + uECC_vli_modMult_fast(t1, d0, e1, &curve_secp224r1); /* t1 <-- d0 * e1 */ + uECC_vli_modMult_fast(e2, d1, e0, &curve_secp224r1); /* e2 <-- d1 * e0 */ + uECC_vli_modAdd(e2, e2, t1, curve_secp224r1.p, num_words_secp224r1); /* e2 <-- e2 + t1 */ + uECC_vli_modSquare_fast(f2, e2, &curve_secp224r1); /* f2 <-- e2^2 */ + uECC_vli_modMult_fast(f2, f2, c, &curve_secp224r1); /* f2 <-- f2 * c */ + /* f2 <-- p - f2 */ + uECC_vli_modSub(f2, curve_secp224r1.p, f2, curve_secp224r1.p, num_words_secp224r1); + uECC_vli_set(d2, t2, num_words_secp224r1); /* d2 <-- t2 */ +} + +/* Routine 3.2.7 RP; from http://www.nsa.gov/ia/_files/nist-routines.pdf */ +static void mod_sqrt_secp224r1_rp(uECC_word_t *d1, + uECC_word_t *e1, + uECC_word_t *f1, + const uECC_word_t *c, + const uECC_word_t *r) { + wordcount_t i; + wordcount_t pow2i = 1; + uECC_word_t d0[num_words_secp224r1]; + uECC_word_t e0[num_words_secp224r1] = {1}; /* e0 <-- 1 */ + uECC_word_t f0[num_words_secp224r1]; + + uECC_vli_set(d0, r, num_words_secp224r1); /* d0 <-- r */ + /* f0 <-- p - c */ + uECC_vli_modSub(f0, curve_secp224r1.p, c, curve_secp224r1.p, num_words_secp224r1); + for (i = 0; i <= 6; i++) { + mod_sqrt_secp224r1_rss(d1, e1, f1, d0, e0, f0, pow2i); /* RSS (d1,e1,f1,d0,e0,f0,2^i) */ + mod_sqrt_secp224r1_rm(d1, e1, f1, c, d1, e1, d0, e0); /* RM (d1,e1,f1,c,d1,e1,d0,e0) */ + uECC_vli_set(d0, d1, num_words_secp224r1); /* d0 <-- d1 */ + uECC_vli_set(e0, e1, num_words_secp224r1); /* e0 <-- e1 */ + uECC_vli_set(f0, f1, num_words_secp224r1); /* f0 <-- f1 */ + pow2i *= 2; + } +} + +/* Compute a = sqrt(a) (mod curve_p). */ +/* Routine 3.2.8 mp_mod_sqrt_224; from http://www.nsa.gov/ia/_files/nist-routines.pdf */ +static void mod_sqrt_secp224r1(uECC_word_t *a, uECC_Curve curve) { + bitcount_t i; + uECC_word_t e1[num_words_secp224r1]; + uECC_word_t f1[num_words_secp224r1]; + uECC_word_t d0[num_words_secp224r1]; + uECC_word_t e0[num_words_secp224r1]; + uECC_word_t f0[num_words_secp224r1]; + uECC_word_t d1[num_words_secp224r1]; + + /* s = a; using constant instead of random value */ + mod_sqrt_secp224r1_rp(d0, e0, f0, a, a); /* RP (d0, e0, f0, c, s) */ + mod_sqrt_secp224r1_rs(d1, e1, f1, d0, e0, f0); /* RS (d1, e1, f1, d0, e0, f0) */ + for (i = 1; i <= 95; i++) { + uECC_vli_set(d0, d1, num_words_secp224r1); /* d0 <-- d1 */ + uECC_vli_set(e0, e1, num_words_secp224r1); /* e0 <-- e1 */ + uECC_vli_set(f0, f1, num_words_secp224r1); /* f0 <-- f1 */ + mod_sqrt_secp224r1_rs(d1, e1, f1, d0, e0, f0); /* RS (d1, e1, f1, d0, e0, f0) */ + if (uECC_vli_isZero(d1, num_words_secp224r1)) { /* if d1 == 0 */ + break; + } + } + uECC_vli_modInv(f1, e0, curve_secp224r1.p, num_words_secp224r1); /* f1 <-- 1 / e0 */ + uECC_vli_modMult_fast(a, d0, f1, &curve_secp224r1); /* a <-- d0 / e0 */ +} +#endif /* uECC_SUPPORT_COMPRESSED_POINT */ + +#if (uECC_OPTIMIZATION_LEVEL > 0) +/* Computes result = product % curve_p + from http://www.nsa.gov/ia/_files/nist-routines.pdf */ +#if uECC_WORD_SIZE == 1 +static void vli_mmod_fast_secp224r1(uint8_t *result, uint8_t *product) { + uint8_t tmp[num_words_secp224r1]; + int8_t carry; + + /* t */ + uECC_vli_set(result, product, num_words_secp224r1); + + /* s1 */ + tmp[0] = tmp[1] = tmp[2] = tmp[3] = 0; + tmp[4] = tmp[5] = tmp[6] = tmp[7] = 0; + tmp[8] = tmp[9] = tmp[10] = tmp[11] = 0; + tmp[12] = product[28]; tmp[13] = product[29]; tmp[14] = product[30]; tmp[15] = product[31]; + tmp[16] = product[32]; tmp[17] = product[33]; tmp[18] = product[34]; tmp[19] = product[35]; + tmp[20] = product[36]; tmp[21] = product[37]; tmp[22] = product[38]; tmp[23] = product[39]; + tmp[24] = product[40]; tmp[25] = product[41]; tmp[26] = product[42]; tmp[27] = product[43]; + carry = uECC_vli_add(result, result, tmp, num_words_secp224r1); + + /* s2 */ + tmp[12] = product[44]; tmp[13] = product[45]; tmp[14] = product[46]; tmp[15] = product[47]; + tmp[16] = product[48]; tmp[17] = product[49]; tmp[18] = product[50]; tmp[19] = product[51]; + tmp[20] = product[52]; tmp[21] = product[53]; tmp[22] = product[54]; tmp[23] = product[55]; + tmp[24] = tmp[25] = tmp[26] = tmp[27] = 0; + carry += uECC_vli_add(result, result, tmp, num_words_secp224r1); + + /* d1 */ + tmp[0] = product[28]; tmp[1] = product[29]; tmp[2] = product[30]; tmp[3] = product[31]; + tmp[4] = product[32]; tmp[5] = product[33]; tmp[6] = product[34]; tmp[7] = product[35]; + tmp[8] = product[36]; tmp[9] = product[37]; tmp[10] = product[38]; tmp[11] = product[39]; + tmp[12] = product[40]; tmp[13] = product[41]; tmp[14] = product[42]; tmp[15] = product[43]; + tmp[16] = product[44]; tmp[17] = product[45]; tmp[18] = product[46]; tmp[19] = product[47]; + tmp[20] = product[48]; tmp[21] = product[49]; tmp[22] = product[50]; tmp[23] = product[51]; + tmp[24] = product[52]; tmp[25] = product[53]; tmp[26] = product[54]; tmp[27] = product[55]; + carry -= uECC_vli_sub(result, result, tmp, num_words_secp224r1); + + /* d2 */ + tmp[0] = product[44]; tmp[1] = product[45]; tmp[2] = product[46]; tmp[3] = product[47]; + tmp[4] = product[48]; tmp[5] = product[49]; tmp[6] = product[50]; tmp[7] = product[51]; + tmp[8] = product[52]; tmp[9] = product[53]; tmp[10] = product[54]; tmp[11] = product[55]; + tmp[12] = tmp[13] = tmp[14] = tmp[15] = 0; + tmp[16] = tmp[17] = tmp[18] = tmp[19] = 0; + tmp[20] = tmp[21] = tmp[22] = tmp[23] = 0; + tmp[24] = tmp[25] = tmp[26] = tmp[27] = 0; + carry -= uECC_vli_sub(result, result, tmp, num_words_secp224r1); + + if (carry < 0) { + do { + carry += uECC_vli_add(result, result, curve_secp224r1.p, num_words_secp224r1); + } while (carry < 0); + } else { + while (carry || uECC_vli_cmp_unsafe(curve_secp224r1.p, result, num_words_secp224r1) != 1) { + carry -= uECC_vli_sub(result, result, curve_secp224r1.p, num_words_secp224r1); + } + } +} +#elif uECC_WORD_SIZE == 4 +static void vli_mmod_fast_secp224r1(uint32_t *result, uint32_t *product) +{ + uint32_t tmp[num_words_secp224r1]; + int carry; + + /* t */ + uECC_vli_set(result, product, num_words_secp224r1); + + /* s1 */ + tmp[0] = tmp[1] = tmp[2] = 0; + tmp[3] = product[7]; + tmp[4] = product[8]; + tmp[5] = product[9]; + tmp[6] = product[10]; + carry = uECC_vli_add(result, result, tmp, num_words_secp224r1); + + /* s2 */ + tmp[3] = product[11]; + tmp[4] = product[12]; + tmp[5] = product[13]; + tmp[6] = 0; + carry += uECC_vli_add(result, result, tmp, num_words_secp224r1); + + /* d1 */ + tmp[0] = product[7]; + tmp[1] = product[8]; + tmp[2] = product[9]; + tmp[3] = product[10]; + tmp[4] = product[11]; + tmp[5] = product[12]; + tmp[6] = product[13]; + carry -= uECC_vli_sub(result, result, tmp, num_words_secp224r1); + + /* d2 */ + tmp[0] = product[11]; + tmp[1] = product[12]; + tmp[2] = product[13]; + tmp[3] = tmp[4] = tmp[5] = tmp[6] = 0; + carry -= uECC_vli_sub(result, result, tmp, num_words_secp224r1); + + if (carry < 0) { + do { + carry += uECC_vli_add(result, result, curve_secp224r1.p, num_words_secp224r1); + } while (carry < 0); + } else { + while (carry || uECC_vli_cmp_unsafe(curve_secp224r1.p, result, num_words_secp224r1) != 1) { + carry -= uECC_vli_sub(result, result, curve_secp224r1.p, num_words_secp224r1); + } + } +} +#else +static void vli_mmod_fast_secp224r1(uint64_t *result, uint64_t *product) +{ + uint64_t tmp[num_words_secp224r1]; + int carry = 0; + + /* t */ + uECC_vli_set(result, product, num_words_secp224r1); + result[num_words_secp224r1 - 1] &= 0xffffffff; + + /* s1 */ + tmp[0] = 0; + tmp[1] = product[3] & 0xffffffff00000000ull; + tmp[2] = product[4]; + tmp[3] = product[5] & 0xffffffff; + uECC_vli_add(result, result, tmp, num_words_secp224r1); + + /* s2 */ + tmp[1] = product[5] & 0xffffffff00000000ull; + tmp[2] = product[6]; + tmp[3] = 0; + uECC_vli_add(result, result, tmp, num_words_secp224r1); + + /* d1 */ + tmp[0] = (product[3] >> 32) | (product[4] << 32); + tmp[1] = (product[4] >> 32) | (product[5] << 32); + tmp[2] = (product[5] >> 32) | (product[6] << 32); + tmp[3] = product[6] >> 32; + carry -= uECC_vli_sub(result, result, tmp, num_words_secp224r1); + + /* d2 */ + tmp[0] = (product[5] >> 32) | (product[6] << 32); + tmp[1] = product[6] >> 32; + tmp[2] = tmp[3] = 0; + carry -= uECC_vli_sub(result, result, tmp, num_words_secp224r1); + + if (carry < 0) { + do { + carry += uECC_vli_add(result, result, curve_secp224r1.p, num_words_secp224r1); + } while (carry < 0); + } else { + while (uECC_vli_cmp_unsafe(curve_secp224r1.p, result, num_words_secp224r1) != 1) { + uECC_vli_sub(result, result, curve_secp224r1.p, num_words_secp224r1); + } + } +} +#endif /* uECC_WORD_SIZE */ +#endif /* (uECC_OPTIMIZATION_LEVEL > 0) */ + +#endif /* uECC_SUPPORTS_secp224r1 */ + +#if uECC_SUPPORTS_secp256r1 + +#if (uECC_OPTIMIZATION_LEVEL > 0) +static void vli_mmod_fast_secp256r1(uECC_word_t *result, uECC_word_t *product); +#endif + +static const struct uECC_Curve_t curve_secp256r1 = { + num_words_secp256r1, + num_bytes_secp256r1, + 256, /* num_n_bits */ + { BYTES_TO_WORDS_8(FF, FF, FF, FF, FF, FF, FF, FF), + BYTES_TO_WORDS_8(FF, FF, FF, FF, 00, 00, 00, 00), + BYTES_TO_WORDS_8(00, 00, 00, 00, 00, 00, 00, 00), + BYTES_TO_WORDS_8(01, 00, 00, 00, FF, FF, FF, FF) }, + { BYTES_TO_WORDS_8(51, 25, 63, FC, C2, CA, B9, F3), + BYTES_TO_WORDS_8(84, 9E, 17, A7, AD, FA, E6, BC), + BYTES_TO_WORDS_8(FF, FF, FF, FF, FF, FF, FF, FF), + BYTES_TO_WORDS_8(00, 00, 00, 00, FF, FF, FF, FF) }, + { BYTES_TO_WORDS_8(96, C2, 98, D8, 45, 39, A1, F4), + BYTES_TO_WORDS_8(A0, 33, EB, 2D, 81, 7D, 03, 77), + BYTES_TO_WORDS_8(F2, 40, A4, 63, E5, E6, BC, F8), + BYTES_TO_WORDS_8(47, 42, 2C, E1, F2, D1, 17, 6B), + + BYTES_TO_WORDS_8(F5, 51, BF, 37, 68, 40, B6, CB), + BYTES_TO_WORDS_8(CE, 5E, 31, 6B, 57, 33, CE, 2B), + BYTES_TO_WORDS_8(16, 9E, 0F, 7C, 4A, EB, E7, 8E), + BYTES_TO_WORDS_8(9B, 7F, 1A, FE, E2, 42, E3, 4F) }, + { BYTES_TO_WORDS_8(4B, 60, D2, 27, 3E, 3C, CE, 3B), + BYTES_TO_WORDS_8(F6, B0, 53, CC, B0, 06, 1D, 65), + BYTES_TO_WORDS_8(BC, 86, 98, 76, 55, BD, EB, B3), + BYTES_TO_WORDS_8(E7, 93, 3A, AA, D8, 35, C6, 5A) }, + &double_jacobian_default, +#if uECC_SUPPORT_COMPRESSED_POINT + &mod_sqrt_default, +#endif + &x_side_default, +#if (uECC_OPTIMIZATION_LEVEL > 0) + &vli_mmod_fast_secp256r1 +#endif +}; + +uECC_Curve uECC_secp256r1(void) { return &curve_secp256r1; } + + +#if (uECC_OPTIMIZATION_LEVEL > 0 && !asm_mmod_fast_secp256r1) +/* Computes result = product % curve_p + from http://www.nsa.gov/ia/_files/nist-routines.pdf */ +#if uECC_WORD_SIZE == 1 +static void vli_mmod_fast_secp256r1(uint8_t *result, uint8_t *product) { + uint8_t tmp[num_words_secp256r1]; + int8_t carry; + + /* t */ + uECC_vli_set(result, product, num_words_secp256r1); + + /* s1 */ + tmp[0] = tmp[1] = tmp[2] = tmp[3] = 0; + tmp[4] = tmp[5] = tmp[6] = tmp[7] = 0; + tmp[8] = tmp[9] = tmp[10] = tmp[11] = 0; + tmp[12] = product[44]; tmp[13] = product[45]; tmp[14] = product[46]; tmp[15] = product[47]; + tmp[16] = product[48]; tmp[17] = product[49]; tmp[18] = product[50]; tmp[19] = product[51]; + tmp[20] = product[52]; tmp[21] = product[53]; tmp[22] = product[54]; tmp[23] = product[55]; + tmp[24] = product[56]; tmp[25] = product[57]; tmp[26] = product[58]; tmp[27] = product[59]; + tmp[28] = product[60]; tmp[29] = product[61]; tmp[30] = product[62]; tmp[31] = product[63]; + carry = uECC_vli_add(tmp, tmp, tmp, num_words_secp256r1); + carry += uECC_vli_add(result, result, tmp, num_words_secp256r1); + + /* s2 */ + tmp[12] = product[48]; tmp[13] = product[49]; tmp[14] = product[50]; tmp[15] = product[51]; + tmp[16] = product[52]; tmp[17] = product[53]; tmp[18] = product[54]; tmp[19] = product[55]; + tmp[20] = product[56]; tmp[21] = product[57]; tmp[22] = product[58]; tmp[23] = product[59]; + tmp[24] = product[60]; tmp[25] = product[61]; tmp[26] = product[62]; tmp[27] = product[63]; + tmp[28] = tmp[29] = tmp[30] = tmp[31] = 0; + carry += uECC_vli_add(tmp, tmp, tmp, num_words_secp256r1); + carry += uECC_vli_add(result, result, tmp, num_words_secp256r1); + + /* s3 */ + tmp[0] = product[32]; tmp[1] = product[33]; tmp[2] = product[34]; tmp[3] = product[35]; + tmp[4] = product[36]; tmp[5] = product[37]; tmp[6] = product[38]; tmp[7] = product[39]; + tmp[8] = product[40]; tmp[9] = product[41]; tmp[10] = product[42]; tmp[11] = product[43]; + tmp[12] = tmp[13] = tmp[14] = tmp[15] = 0; + tmp[16] = tmp[17] = tmp[18] = tmp[19] = 0; + tmp[20] = tmp[21] = tmp[22] = tmp[23] = 0; + tmp[24] = product[56]; tmp[25] = product[57]; tmp[26] = product[58]; tmp[27] = product[59]; + tmp[28] = product[60]; tmp[29] = product[61]; tmp[30] = product[62]; tmp[31] = product[63]; + carry += uECC_vli_add(result, result, tmp, num_words_secp256r1); + + /* s4 */ + tmp[0] = product[36]; tmp[1] = product[37]; tmp[2] = product[38]; tmp[3] = product[39]; + tmp[4] = product[40]; tmp[5] = product[41]; tmp[6] = product[42]; tmp[7] = product[43]; + tmp[8] = product[44]; tmp[9] = product[45]; tmp[10] = product[46]; tmp[11] = product[47]; + tmp[12] = product[52]; tmp[13] = product[53]; tmp[14] = product[54]; tmp[15] = product[55]; + tmp[16] = product[56]; tmp[17] = product[57]; tmp[18] = product[58]; tmp[19] = product[59]; + tmp[20] = product[60]; tmp[21] = product[61]; tmp[22] = product[62]; tmp[23] = product[63]; + tmp[24] = product[52]; tmp[25] = product[53]; tmp[26] = product[54]; tmp[27] = product[55]; + tmp[28] = product[32]; tmp[29] = product[33]; tmp[30] = product[34]; tmp[31] = product[35]; + carry += uECC_vli_add(result, result, tmp, num_words_secp256r1); + + /* d1 */ + tmp[0] = product[44]; tmp[1] = product[45]; tmp[2] = product[46]; tmp[3] = product[47]; + tmp[4] = product[48]; tmp[5] = product[49]; tmp[6] = product[50]; tmp[7] = product[51]; + tmp[8] = product[52]; tmp[9] = product[53]; tmp[10] = product[54]; tmp[11] = product[55]; + tmp[12] = tmp[13] = tmp[14] = tmp[15] = 0; + tmp[16] = tmp[17] = tmp[18] = tmp[19] = 0; + tmp[20] = tmp[21] = tmp[22] = tmp[23] = 0; + tmp[24] = product[32]; tmp[25] = product[33]; tmp[26] = product[34]; tmp[27] = product[35]; + tmp[28] = product[40]; tmp[29] = product[41]; tmp[30] = product[42]; tmp[31] = product[43]; + carry -= uECC_vli_sub(result, result, tmp, num_words_secp256r1); + + /* d2 */ + tmp[0] = product[48]; tmp[1] = product[49]; tmp[2] = product[50]; tmp[3] = product[51]; + tmp[4] = product[52]; tmp[5] = product[53]; tmp[6] = product[54]; tmp[7] = product[55]; + tmp[8] = product[56]; tmp[9] = product[57]; tmp[10] = product[58]; tmp[11] = product[59]; + tmp[12] = product[60]; tmp[13] = product[61]; tmp[14] = product[62]; tmp[15] = product[63]; + tmp[16] = tmp[17] = tmp[18] = tmp[19] = 0; + tmp[20] = tmp[21] = tmp[22] = tmp[23] = 0; + tmp[24] = product[36]; tmp[25] = product[37]; tmp[26] = product[38]; tmp[27] = product[39]; + tmp[28] = product[44]; tmp[29] = product[45]; tmp[30] = product[46]; tmp[31] = product[47]; + carry -= uECC_vli_sub(result, result, tmp, num_words_secp256r1); + + /* d3 */ + tmp[0] = product[52]; tmp[1] = product[53]; tmp[2] = product[54]; tmp[3] = product[55]; + tmp[4] = product[56]; tmp[5] = product[57]; tmp[6] = product[58]; tmp[7] = product[59]; + tmp[8] = product[60]; tmp[9] = product[61]; tmp[10] = product[62]; tmp[11] = product[63]; + tmp[12] = product[32]; tmp[13] = product[33]; tmp[14] = product[34]; tmp[15] = product[35]; + tmp[16] = product[36]; tmp[17] = product[37]; tmp[18] = product[38]; tmp[19] = product[39]; + tmp[20] = product[40]; tmp[21] = product[41]; tmp[22] = product[42]; tmp[23] = product[43]; + tmp[24] = tmp[25] = tmp[26] = tmp[27] = 0; + tmp[28] = product[48]; tmp[29] = product[49]; tmp[30] = product[50]; tmp[31] = product[51]; + carry -= uECC_vli_sub(result, result, tmp, num_words_secp256r1); + + /* d4 */ + tmp[0] = product[56]; tmp[1] = product[57]; tmp[2] = product[58]; tmp[3] = product[59]; + tmp[4] = product[60]; tmp[5] = product[61]; tmp[6] = product[62]; tmp[7] = product[63]; + tmp[8] = tmp[9] = tmp[10] = tmp[11] = 0; + tmp[12] = product[36]; tmp[13] = product[37]; tmp[14] = product[38]; tmp[15] = product[39]; + tmp[16] = product[40]; tmp[17] = product[41]; tmp[18] = product[42]; tmp[19] = product[43]; + tmp[20] = product[44]; tmp[21] = product[45]; tmp[22] = product[46]; tmp[23] = product[47]; + tmp[24] = tmp[25] = tmp[26] = tmp[27] = 0; + tmp[28] = product[52]; tmp[29] = product[53]; tmp[30] = product[54]; tmp[31] = product[55]; + carry -= uECC_vli_sub(result, result, tmp, num_words_secp256r1); + + if (carry < 0) { + do { + carry += uECC_vli_add(result, result, curve_secp256r1.p, num_words_secp256r1); + } while (carry < 0); + } else { + while (carry || uECC_vli_cmp_unsafe(curve_secp256r1.p, result, num_words_secp256r1) != 1) { + carry -= uECC_vli_sub(result, result, curve_secp256r1.p, num_words_secp256r1); + } + } +} +#elif uECC_WORD_SIZE == 4 +static void vli_mmod_fast_secp256r1(uint32_t *result, uint32_t *product) { + uint32_t tmp[num_words_secp256r1]; + int carry; + + /* t */ + uECC_vli_set(result, product, num_words_secp256r1); + + /* s1 */ + tmp[0] = tmp[1] = tmp[2] = 0; + tmp[3] = product[11]; + tmp[4] = product[12]; + tmp[5] = product[13]; + tmp[6] = product[14]; + tmp[7] = product[15]; + carry = uECC_vli_add(tmp, tmp, tmp, num_words_secp256r1); + carry += uECC_vli_add(result, result, tmp, num_words_secp256r1); + + /* s2 */ + tmp[3] = product[12]; + tmp[4] = product[13]; + tmp[5] = product[14]; + tmp[6] = product[15]; + tmp[7] = 0; + carry += uECC_vli_add(tmp, tmp, tmp, num_words_secp256r1); + carry += uECC_vli_add(result, result, tmp, num_words_secp256r1); + + /* s3 */ + tmp[0] = product[8]; + tmp[1] = product[9]; + tmp[2] = product[10]; + tmp[3] = tmp[4] = tmp[5] = 0; + tmp[6] = product[14]; + tmp[7] = product[15]; + carry += uECC_vli_add(result, result, tmp, num_words_secp256r1); + + /* s4 */ + tmp[0] = product[9]; + tmp[1] = product[10]; + tmp[2] = product[11]; + tmp[3] = product[13]; + tmp[4] = product[14]; + tmp[5] = product[15]; + tmp[6] = product[13]; + tmp[7] = product[8]; + carry += uECC_vli_add(result, result, tmp, num_words_secp256r1); + + /* d1 */ + tmp[0] = product[11]; + tmp[1] = product[12]; + tmp[2] = product[13]; + tmp[3] = tmp[4] = tmp[5] = 0; + tmp[6] = product[8]; + tmp[7] = product[10]; + carry -= uECC_vli_sub(result, result, tmp, num_words_secp256r1); + + /* d2 */ + tmp[0] = product[12]; + tmp[1] = product[13]; + tmp[2] = product[14]; + tmp[3] = product[15]; + tmp[4] = tmp[5] = 0; + tmp[6] = product[9]; + tmp[7] = product[11]; + carry -= uECC_vli_sub(result, result, tmp, num_words_secp256r1); + + /* d3 */ + tmp[0] = product[13]; + tmp[1] = product[14]; + tmp[2] = product[15]; + tmp[3] = product[8]; + tmp[4] = product[9]; + tmp[5] = product[10]; + tmp[6] = 0; + tmp[7] = product[12]; + carry -= uECC_vli_sub(result, result, tmp, num_words_secp256r1); + + /* d4 */ + tmp[0] = product[14]; + tmp[1] = product[15]; + tmp[2] = 0; + tmp[3] = product[9]; + tmp[4] = product[10]; + tmp[5] = product[11]; + tmp[6] = 0; + tmp[7] = product[13]; + carry -= uECC_vli_sub(result, result, tmp, num_words_secp256r1); + + if (carry < 0) { + do { + carry += uECC_vli_add(result, result, curve_secp256r1.p, num_words_secp256r1); + } while (carry < 0); + } else { + while (carry || uECC_vli_cmp_unsafe(curve_secp256r1.p, result, num_words_secp256r1) != 1) { + carry -= uECC_vli_sub(result, result, curve_secp256r1.p, num_words_secp256r1); + } + } +} +#else +static void vli_mmod_fast_secp256r1(uint64_t *result, uint64_t *product) { + uint64_t tmp[num_words_secp256r1]; + int carry; + + /* t */ + uECC_vli_set(result, product, num_words_secp256r1); + + /* s1 */ + tmp[0] = 0; + tmp[1] = product[5] & 0xffffffff00000000ull; + tmp[2] = product[6]; + tmp[3] = product[7]; + carry = (int)uECC_vli_add(tmp, tmp, tmp, num_words_secp256r1); + carry += uECC_vli_add(result, result, tmp, num_words_secp256r1); + + /* s2 */ + tmp[1] = product[6] << 32; + tmp[2] = (product[6] >> 32) | (product[7] << 32); + tmp[3] = product[7] >> 32; + carry += uECC_vli_add(tmp, tmp, tmp, num_words_secp256r1); + carry += uECC_vli_add(result, result, tmp, num_words_secp256r1); + + /* s3 */ + tmp[0] = product[4]; + tmp[1] = product[5] & 0xffffffff; + tmp[2] = 0; + tmp[3] = product[7]; + carry += uECC_vli_add(result, result, tmp, num_words_secp256r1); + + /* s4 */ + tmp[0] = (product[4] >> 32) | (product[5] << 32); + tmp[1] = (product[5] >> 32) | (product[6] & 0xffffffff00000000ull); + tmp[2] = product[7]; + tmp[3] = (product[6] >> 32) | (product[4] << 32); + carry += uECC_vli_add(result, result, tmp, num_words_secp256r1); + + /* d1 */ + tmp[0] = (product[5] >> 32) | (product[6] << 32); + tmp[1] = (product[6] >> 32); + tmp[2] = 0; + tmp[3] = (product[4] & 0xffffffff) | (product[5] << 32); + carry -= uECC_vli_sub(result, result, tmp, num_words_secp256r1); + + /* d2 */ + tmp[0] = product[6]; + tmp[1] = product[7]; + tmp[2] = 0; + tmp[3] = (product[4] >> 32) | (product[5] & 0xffffffff00000000ull); + carry -= uECC_vli_sub(result, result, tmp, num_words_secp256r1); + + /* d3 */ + tmp[0] = (product[6] >> 32) | (product[7] << 32); + tmp[1] = (product[7] >> 32) | (product[4] << 32); + tmp[2] = (product[4] >> 32) | (product[5] << 32); + tmp[3] = (product[6] << 32); + carry -= uECC_vli_sub(result, result, tmp, num_words_secp256r1); + + /* d4 */ + tmp[0] = product[7]; + tmp[1] = product[4] & 0xffffffff00000000ull; + tmp[2] = product[5]; + tmp[3] = product[6] & 0xffffffff00000000ull; + carry -= uECC_vli_sub(result, result, tmp, num_words_secp256r1); + + if (carry < 0) { + do { + carry += uECC_vli_add(result, result, curve_secp256r1.p, num_words_secp256r1); + } while (carry < 0); + } else { + while (carry || uECC_vli_cmp_unsafe(curve_secp256r1.p, result, num_words_secp256r1) != 1) { + carry -= uECC_vli_sub(result, result, curve_secp256r1.p, num_words_secp256r1); + } + } +} +#endif /* uECC_WORD_SIZE */ +#endif /* (uECC_OPTIMIZATION_LEVEL > 0 && !asm_mmod_fast_secp256r1) */ + +#endif /* uECC_SUPPORTS_secp256r1 */ + +#if uECC_SUPPORTS_secp256k1 + +static void double_jacobian_secp256k1(uECC_word_t * X1, + uECC_word_t * Y1, + uECC_word_t * Z1, + uECC_Curve curve); +static void x_side_secp256k1(uECC_word_t *result, const uECC_word_t *x, uECC_Curve curve); +#if (uECC_OPTIMIZATION_LEVEL > 0) +static void vli_mmod_fast_secp256k1(uECC_word_t *result, uECC_word_t *product); +#endif + +static const struct uECC_Curve_t curve_secp256k1 = { + num_words_secp256k1, + num_bytes_secp256k1, + 256, /* num_n_bits */ + { BYTES_TO_WORDS_8(2F, FC, FF, FF, FE, FF, FF, FF), + BYTES_TO_WORDS_8(FF, FF, FF, FF, FF, FF, FF, FF), + BYTES_TO_WORDS_8(FF, FF, FF, FF, FF, FF, FF, FF), + BYTES_TO_WORDS_8(FF, FF, FF, FF, FF, FF, FF, FF) }, + { BYTES_TO_WORDS_8(41, 41, 36, D0, 8C, 5E, D2, BF), + BYTES_TO_WORDS_8(3B, A0, 48, AF, E6, DC, AE, BA), + BYTES_TO_WORDS_8(FE, FF, FF, FF, FF, FF, FF, FF), + BYTES_TO_WORDS_8(FF, FF, FF, FF, FF, FF, FF, FF) }, + { BYTES_TO_WORDS_8(98, 17, F8, 16, 5B, 81, F2, 59), + BYTES_TO_WORDS_8(D9, 28, CE, 2D, DB, FC, 9B, 02), + BYTES_TO_WORDS_8(07, 0B, 87, CE, 95, 62, A0, 55), + BYTES_TO_WORDS_8(AC, BB, DC, F9, 7E, 66, BE, 79), + + BYTES_TO_WORDS_8(B8, D4, 10, FB, 8F, D0, 47, 9C), + BYTES_TO_WORDS_8(19, 54, 85, A6, 48, B4, 17, FD), + BYTES_TO_WORDS_8(A8, 08, 11, 0E, FC, FB, A4, 5D), + BYTES_TO_WORDS_8(65, C4, A3, 26, 77, DA, 3A, 48) }, + { BYTES_TO_WORDS_8(07, 00, 00, 00, 00, 00, 00, 00), + BYTES_TO_WORDS_8(00, 00, 00, 00, 00, 00, 00, 00), + BYTES_TO_WORDS_8(00, 00, 00, 00, 00, 00, 00, 00), + BYTES_TO_WORDS_8(00, 00, 00, 00, 00, 00, 00, 00) }, + &double_jacobian_secp256k1, +#if uECC_SUPPORT_COMPRESSED_POINT + &mod_sqrt_default, +#endif + &x_side_secp256k1, +#if (uECC_OPTIMIZATION_LEVEL > 0) + &vli_mmod_fast_secp256k1 +#endif +}; + +uECC_Curve uECC_secp256k1(void) { return &curve_secp256k1; } + + +/* Double in place */ +static void double_jacobian_secp256k1(uECC_word_t * X1, + uECC_word_t * Y1, + uECC_word_t * Z1, + uECC_Curve curve) { + /* t1 = X, t2 = Y, t3 = Z */ + uECC_word_t t4[num_words_secp256k1]; + uECC_word_t t5[num_words_secp256k1]; + + if (uECC_vli_isZero(Z1, num_words_secp256k1)) { + return; + } + + uECC_vli_modSquare_fast(t5, Y1, curve); /* t5 = y1^2 */ + uECC_vli_modMult_fast(t4, X1, t5, curve); /* t4 = x1*y1^2 = A */ + uECC_vli_modSquare_fast(X1, X1, curve); /* t1 = x1^2 */ + uECC_vli_modSquare_fast(t5, t5, curve); /* t5 = y1^4 */ + uECC_vli_modMult_fast(Z1, Y1, Z1, curve); /* t3 = y1*z1 = z3 */ + + uECC_vli_modAdd(Y1, X1, X1, curve->p, num_words_secp256k1); /* t2 = 2*x1^2 */ + uECC_vli_modAdd(Y1, Y1, X1, curve->p, num_words_secp256k1); /* t2 = 3*x1^2 */ + if (uECC_vli_testBit(Y1, 0)) { + uECC_word_t carry = uECC_vli_add(Y1, Y1, curve->p, num_words_secp256k1); + uECC_vli_rshift1(Y1, num_words_secp256k1); + Y1[num_words_secp256k1 - 1] |= carry << (uECC_WORD_BITS - 1); + } else { + uECC_vli_rshift1(Y1, num_words_secp256k1); + } + /* t2 = 3/2*(x1^2) = B */ + + uECC_vli_modSquare_fast(X1, Y1, curve); /* t1 = B^2 */ + uECC_vli_modSub(X1, X1, t4, curve->p, num_words_secp256k1); /* t1 = B^2 - A */ + uECC_vli_modSub(X1, X1, t4, curve->p, num_words_secp256k1); /* t1 = B^2 - 2A = x3 */ + + uECC_vli_modSub(t4, t4, X1, curve->p, num_words_secp256k1); /* t4 = A - x3 */ + uECC_vli_modMult_fast(Y1, Y1, t4, curve); /* t2 = B * (A - x3) */ + uECC_vli_modSub(Y1, Y1, t5, curve->p, num_words_secp256k1); /* t2 = B * (A - x3) - y1^4 = y3 */ +} + +/* Computes result = x^3 + b. result must not overlap x. */ +static void x_side_secp256k1(uECC_word_t *result, const uECC_word_t *x, uECC_Curve curve) { + uECC_vli_modSquare_fast(result, x, curve); /* r = x^2 */ + uECC_vli_modMult_fast(result, result, x, curve); /* r = x^3 */ + uECC_vli_modAdd(result, result, curve->b, curve->p, num_words_secp256k1); /* r = x^3 + b */ +} + +#if (uECC_OPTIMIZATION_LEVEL > 0 && !asm_mmod_fast_secp256k1) +static void omega_mult_secp256k1(uECC_word_t *result, const uECC_word_t *right); +static void vli_mmod_fast_secp256k1(uECC_word_t *result, uECC_word_t *product) { + uECC_word_t tmp[2 * num_words_secp256k1]; + uECC_word_t carry; + + uECC_vli_clear(tmp, num_words_secp256k1); + uECC_vli_clear(tmp + num_words_secp256k1, num_words_secp256k1); + + omega_mult_secp256k1(tmp, product + num_words_secp256k1); /* (Rq, q) = q * c */ + + carry = uECC_vli_add(result, product, tmp, num_words_secp256k1); /* (C, r) = r + q */ + uECC_vli_clear(product, num_words_secp256k1); + omega_mult_secp256k1(product, tmp + num_words_secp256k1); /* Rq*c */ + carry += uECC_vli_add(result, result, product, num_words_secp256k1); /* (C1, r) = r + Rq*c */ + + while (carry > 0) { + --carry; + uECC_vli_sub(result, result, curve_secp256k1.p, num_words_secp256k1); + } + if (uECC_vli_cmp_unsafe(result, curve_secp256k1.p, num_words_secp256k1) > 0) { + uECC_vli_sub(result, result, curve_secp256k1.p, num_words_secp256k1); + } +} + +#if uECC_WORD_SIZE == 1 +static void omega_mult_secp256k1(uint8_t * result, const uint8_t * right) { + /* Multiply by (2^32 + 2^9 + 2^8 + 2^7 + 2^6 + 2^4 + 1). */ + uECC_word_t r0 = 0; + uECC_word_t r1 = 0; + uECC_word_t r2 = 0; + wordcount_t k; + + /* Multiply by (2^9 + 2^8 + 2^7 + 2^6 + 2^4 + 1). */ + muladd(0xD1, right[0], &r0, &r1, &r2); + result[0] = r0; + r0 = r1; + r1 = r2; + /* r2 is still 0 */ + + for (k = 1; k < num_words_secp256k1; ++k) { + muladd(0x03, right[k - 1], &r0, &r1, &r2); + muladd(0xD1, right[k], &r0, &r1, &r2); + result[k] = r0; + r0 = r1; + r1 = r2; + r2 = 0; + } + muladd(0x03, right[num_words_secp256k1 - 1], &r0, &r1, &r2); + result[num_words_secp256k1] = r0; + result[num_words_secp256k1 + 1] = r1; + /* add the 2^32 multiple */ + result[4 + num_words_secp256k1] = + uECC_vli_add(result + 4, result + 4, right, num_words_secp256k1); +} +#elif uECC_WORD_SIZE == 4 +static void omega_mult_secp256k1(uint32_t * result, const uint32_t * right) { + /* Multiply by (2^9 + 2^8 + 2^7 + 2^6 + 2^4 + 1). */ + uint32_t carry = 0; + wordcount_t k; + + for (k = 0; k < num_words_secp256k1; ++k) { + uint64_t p = (uint64_t)0x3D1 * right[k] + carry; + result[k] = (uint32_t) p; + carry = p >> 32; + } + result[num_words_secp256k1] = carry; + /* add the 2^32 multiple */ + result[1 + num_words_secp256k1] = + uECC_vli_add(result + 1, result + 1, right, num_words_secp256k1); +} +#else +static void omega_mult_secp256k1(uint64_t * result, const uint64_t * right) { + uECC_word_t r0 = 0; + uECC_word_t r1 = 0; + uECC_word_t r2 = 0; + wordcount_t k; + + /* Multiply by (2^32 + 2^9 + 2^8 + 2^7 + 2^6 + 2^4 + 1). */ + for (k = 0; k < num_words_secp256k1; ++k) { + muladd(0x1000003D1ull, right[k], &r0, &r1, &r2); + result[k] = r0; + r0 = r1; + r1 = r2; + r2 = 0; + } + result[num_words_secp256k1] = r0; +} +#endif /* uECC_WORD_SIZE */ +#endif /* (uECC_OPTIMIZATION_LEVEL > 0 && && !asm_mmod_fast_secp256k1) */ + +#endif /* uECC_SUPPORTS_secp256k1 */ + +#endif /* _UECC_CURVE_SPECIFIC_H_ */
diff -r 000000000000 -r b6fdeddc0bc9 platform-specific.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/platform-specific.h Thu Sep 07 12:10:11 2017 +0000 @@ -0,0 +1,71 @@ +/* Copyright 2015, Kenneth MacKay. Licensed under the BSD 2-clause license. */ + +#ifndef _UECC_PLATFORM_SPECIFIC_H_ +#define _UECC_PLATFORM_SPECIFIC_H_ + +#include "types.h" + +#if (defined(_WIN32) || defined(_WIN64)) +/* Windows */ + +// use pragma syntax to prevent tweaking the linker script for getting CryptXYZ function +#pragma comment(lib, "crypt32.lib") +#pragma comment(lib, "advapi32.lib") + +#define WIN32_LEAN_AND_MEAN +#include <windows.h> +#include <wincrypt.h> + +static int default_RNG(uint8_t *dest, unsigned size) { + HCRYPTPROV prov; + if (!CryptAcquireContext(&prov, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT)) { + return 0; + } + + CryptGenRandom(prov, size, (BYTE *)dest); + CryptReleaseContext(prov, 0); + return 1; +} +#define default_RNG_defined 1 + +#elif defined(unix) || defined(__linux__) || defined(__unix__) || defined(__unix) || \ + (defined(__APPLE__) && defined(__MACH__)) || defined(uECC_POSIX) + +/* Some POSIX-like system with /dev/urandom or /dev/random. */ +#include <sys/types.h> +#include <fcntl.h> +#include <unistd.h> + +#ifndef O_CLOEXEC + #define O_CLOEXEC 0 +#endif + +static int default_RNG(uint8_t *dest, unsigned size) { + int fd = open("/dev/urandom", O_RDONLY | O_CLOEXEC); + if (fd == -1) { + fd = open("/dev/random", O_RDONLY | O_CLOEXEC); + if (fd == -1) { + return 0; + } + } + + char *ptr = (char *)dest; + size_t left = size; + while (left > 0) { + ssize_t bytes_read = read(fd, ptr, left); + if (bytes_read <= 0) { // read failed + close(fd); + return 0; + } + left -= bytes_read; + ptr += bytes_read; + } + + close(fd); + return 1; +} +#define default_RNG_defined 1 + +#endif /* platform */ + +#endif /* _UECC_PLATFORM_SPECIFIC_H_ */
diff -r 000000000000 -r b6fdeddc0bc9 types.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/types.h Thu Sep 07 12:10:11 2017 +0000 @@ -0,0 +1,108 @@ +/* Copyright 2015, Kenneth MacKay. Licensed under the BSD 2-clause license. */ + +#ifndef _UECC_TYPES_H_ +#define _UECC_TYPES_H_ + +#ifndef uECC_PLATFORM + #if __AVR__ + #define uECC_PLATFORM uECC_avr + #elif defined(__thumb2__) || defined(_M_ARMT) /* I think MSVC only supports Thumb-2 targets */ + #define uECC_PLATFORM uECC_arm_thumb2 + #elif defined(__thumb__) + #define uECC_PLATFORM uECC_arm_thumb + #elif defined(__arm__) || defined(_M_ARM) + #define uECC_PLATFORM uECC_arm + #elif defined(__aarch64__) + #define uECC_PLATFORM uECC_arm64 + #elif defined(__i386__) || defined(_M_IX86) || defined(_X86_) || defined(__I86__) + #define uECC_PLATFORM uECC_x86 + #elif defined(__amd64__) || defined(_M_X64) + #define uECC_PLATFORM uECC_x86_64 + #else + #define uECC_PLATFORM uECC_arch_other + #endif +#endif + +#ifndef uECC_ARM_USE_UMAAL + #if (uECC_PLATFORM == uECC_arm) && (__ARM_ARCH >= 6) + #define uECC_ARM_USE_UMAAL 1 + #elif (uECC_PLATFORM == uECC_arm_thumb2) && (__ARM_ARCH >= 6) && !__ARM_ARCH_7M__ + #define uECC_ARM_USE_UMAAL 1 + #else + #define uECC_ARM_USE_UMAAL 0 + #endif +#endif + +#ifndef uECC_WORD_SIZE + #if uECC_PLATFORM == uECC_avr + #define uECC_WORD_SIZE 1 + #elif (uECC_PLATFORM == uECC_x86_64 || uECC_PLATFORM == uECC_arm64) + #define uECC_WORD_SIZE 8 + #else + #define uECC_WORD_SIZE 4 + #endif +#endif + +#if (uECC_WORD_SIZE != 1) && (uECC_WORD_SIZE != 4) && (uECC_WORD_SIZE != 8) + #error "Unsupported value for uECC_WORD_SIZE" +#endif + +#if ((uECC_PLATFORM == uECC_avr) && (uECC_WORD_SIZE != 1)) + #pragma message ("uECC_WORD_SIZE must be 1 for AVR") + #undef uECC_WORD_SIZE + #define uECC_WORD_SIZE 1 +#endif + +#if ((uECC_PLATFORM == uECC_arm || uECC_PLATFORM == uECC_arm_thumb || \ + uECC_PLATFORM == uECC_arm_thumb2) && \ + (uECC_WORD_SIZE != 4)) + #pragma message ("uECC_WORD_SIZE must be 4 for ARM") + #undef uECC_WORD_SIZE + #define uECC_WORD_SIZE 4 +#endif + +#if defined(__SIZEOF_INT128__) || ((__clang_major__ * 100 + __clang_minor__) >= 302) + #define SUPPORTS_INT128 1 +#else + #define SUPPORTS_INT128 0 +#endif + +typedef int8_t wordcount_t; +typedef int16_t bitcount_t; +typedef int8_t cmpresult_t; + +#if (uECC_WORD_SIZE == 1) + +typedef uint8_t uECC_word_t; +typedef uint16_t uECC_dword_t; + +#define HIGH_BIT_SET 0x80 +#define uECC_WORD_BITS 8 +#define uECC_WORD_BITS_SHIFT 3 +#define uECC_WORD_BITS_MASK 0x07 + +#elif (uECC_WORD_SIZE == 4) + +typedef uint32_t uECC_word_t; +typedef uint64_t uECC_dword_t; + +#define HIGH_BIT_SET 0x80000000 +#define uECC_WORD_BITS 32 +#define uECC_WORD_BITS_SHIFT 5 +#define uECC_WORD_BITS_MASK 0x01F + +#elif (uECC_WORD_SIZE == 8) + +typedef uint64_t uECC_word_t; +#if SUPPORTS_INT128 +typedef unsigned __int128 uECC_dword_t; +#endif + +#define HIGH_BIT_SET 0x8000000000000000ull +#define uECC_WORD_BITS 64 +#define uECC_WORD_BITS_SHIFT 6 +#define uECC_WORD_BITS_MASK 0x03F + +#endif /* uECC_WORD_SIZE */ + +#endif /* _UECC_TYPES_H_ */
diff -r 000000000000 -r b6fdeddc0bc9 uECC.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/uECC.cpp Thu Sep 07 12:10:11 2017 +0000 @@ -0,0 +1,1644 @@ +/* Copyright 2014, Kenneth MacKay. Licensed under the BSD 2-clause license. */ + +#include "uECC.h" +#include "uECC_vli.h" + +#ifndef uECC_RNG_MAX_TRIES + #define uECC_RNG_MAX_TRIES 64 +#endif + +#if uECC_ENABLE_VLI_API + #define uECC_VLI_API +#else + #define uECC_VLI_API static +#endif + +#define CONCATX(a, ...) a ## __VA_ARGS__ +#define CONCAT(a, ...) CONCATX(a, __VA_ARGS__) + +#define STRX(a) #a +#define STR(a) STRX(a) + +#define EVAL(...) EVAL1(EVAL1(EVAL1(EVAL1(__VA_ARGS__)))) +#define EVAL1(...) EVAL2(EVAL2(EVAL2(EVAL2(__VA_ARGS__)))) +#define EVAL2(...) EVAL3(EVAL3(EVAL3(EVAL3(__VA_ARGS__)))) +#define EVAL3(...) EVAL4(EVAL4(EVAL4(EVAL4(__VA_ARGS__)))) +#define EVAL4(...) __VA_ARGS__ + +#define DEC_1 0 +#define DEC_2 1 +#define DEC_3 2 +#define DEC_4 3 +#define DEC_5 4 +#define DEC_6 5 +#define DEC_7 6 +#define DEC_8 7 +#define DEC_9 8 +#define DEC_10 9 +#define DEC_11 10 +#define DEC_12 11 +#define DEC_13 12 +#define DEC_14 13 +#define DEC_15 14 +#define DEC_16 15 +#define DEC_17 16 +#define DEC_18 17 +#define DEC_19 18 +#define DEC_20 19 +#define DEC_21 20 +#define DEC_22 21 +#define DEC_23 22 +#define DEC_24 23 +#define DEC_25 24 +#define DEC_26 25 +#define DEC_27 26 +#define DEC_28 27 +#define DEC_29 28 +#define DEC_30 29 +#define DEC_31 30 +#define DEC_32 31 + +#define DEC(N) CONCAT(DEC_, N) + +#define SECOND_ARG(_, val, ...) val +#define SOME_CHECK_0 ~, 0 +#define GET_SECOND_ARG(...) SECOND_ARG(__VA_ARGS__, SOME,) +#define SOME_OR_0(N) GET_SECOND_ARG(CONCAT(SOME_CHECK_, N)) + +#define EMPTY(...) +#define DEFER(...) __VA_ARGS__ EMPTY() + +#define REPEAT_NAME_0() REPEAT_0 +#define REPEAT_NAME_SOME() REPEAT_SOME +#define REPEAT_0(...) +#define REPEAT_SOME(N, stuff) DEFER(CONCAT(REPEAT_NAME_, SOME_OR_0(DEC(N))))()(DEC(N), stuff) stuff +#define REPEAT(N, stuff) EVAL(REPEAT_SOME(N, stuff)) + +#define REPEATM_NAME_0() REPEATM_0 +#define REPEATM_NAME_SOME() REPEATM_SOME +#define REPEATM_0(...) +#define REPEATM_SOME(N, macro) macro(N) \ + DEFER(CONCAT(REPEATM_NAME_, SOME_OR_0(DEC(N))))()(DEC(N), macro) +#define REPEATM(N, macro) EVAL(REPEATM_SOME(N, macro)) + +//#include "platform-specific.inc" +#include "platform-specific.h" + +#if (uECC_WORD_SIZE == 1) + #if uECC_SUPPORTS_secp160r1 + #define uECC_MAX_WORDS 21 /* Due to the size of curve_n. */ + #endif + #if uECC_SUPPORTS_secp192r1 + #undef uECC_MAX_WORDS + #define uECC_MAX_WORDS 24 + #endif + #if uECC_SUPPORTS_secp224r1 + #undef uECC_MAX_WORDS + #define uECC_MAX_WORDS 28 + #endif + #if (uECC_SUPPORTS_secp256r1 || uECC_SUPPORTS_secp256k1) + #undef uECC_MAX_WORDS + #define uECC_MAX_WORDS 32 + #endif +#elif (uECC_WORD_SIZE == 4) + #if uECC_SUPPORTS_secp160r1 + #define uECC_MAX_WORDS 6 /* Due to the size of curve_n. */ + #endif + #if uECC_SUPPORTS_secp192r1 + #undef uECC_MAX_WORDS + #define uECC_MAX_WORDS 6 + #endif + #if uECC_SUPPORTS_secp224r1 + #undef uECC_MAX_WORDS + #define uECC_MAX_WORDS 7 + #endif + #if (uECC_SUPPORTS_secp256r1 || uECC_SUPPORTS_secp256k1) + #undef uECC_MAX_WORDS + #define uECC_MAX_WORDS 8 + #endif +#elif (uECC_WORD_SIZE == 8) + #if uECC_SUPPORTS_secp160r1 + #define uECC_MAX_WORDS 3 + #endif + #if uECC_SUPPORTS_secp192r1 + #undef uECC_MAX_WORDS + #define uECC_MAX_WORDS 3 + #endif + #if uECC_SUPPORTS_secp224r1 + #undef uECC_MAX_WORDS + #define uECC_MAX_WORDS 4 + #endif + #if (uECC_SUPPORTS_secp256r1 || uECC_SUPPORTS_secp256k1) + #undef uECC_MAX_WORDS + #define uECC_MAX_WORDS 4 + #endif +#endif /* uECC_WORD_SIZE */ + +#define BITS_TO_WORDS(num_bits) ((num_bits + ((uECC_WORD_SIZE * 8) - 1)) / (uECC_WORD_SIZE * 8)) +#define BITS_TO_BYTES(num_bits) ((num_bits + 7) / 8) + +struct uECC_Curve_t { + wordcount_t num_words; + wordcount_t num_bytes; + bitcount_t num_n_bits; + uECC_word_t p[uECC_MAX_WORDS]; + uECC_word_t n[uECC_MAX_WORDS]; + uECC_word_t G[uECC_MAX_WORDS * 2]; + uECC_word_t b[uECC_MAX_WORDS]; + void (*double_jacobian)(uECC_word_t * X1, + uECC_word_t * Y1, + uECC_word_t * Z1, + uECC_Curve curve); +#if uECC_SUPPORT_COMPRESSED_POINT + void (*mod_sqrt)(uECC_word_t *a, uECC_Curve curve); +#endif + void (*x_side)(uECC_word_t *result, const uECC_word_t *x, uECC_Curve curve); +#if (uECC_OPTIMIZATION_LEVEL > 0) + void (*mmod_fast)(uECC_word_t *result, uECC_word_t *product); +#endif +}; + +#if uECC_VLI_NATIVE_LITTLE_ENDIAN +static void bcopy(uint8_t *dst, + const uint8_t *src, + unsigned num_bytes) { + while (0 != num_bytes) { + num_bytes--; + dst[num_bytes] = src[num_bytes]; + } +} +#endif + +static cmpresult_t uECC_vli_cmp_unsafe(const uECC_word_t *left, + const uECC_word_t *right, + wordcount_t num_words); + +#if (uECC_PLATFORM == uECC_arm || uECC_PLATFORM == uECC_arm_thumb || \ + uECC_PLATFORM == uECC_arm_thumb2) + //#include "asm_arm.inc" + #include "asm_arm.h" +#if (uECC_PLATFORM == uECC_arm) + #warning uECC_arm +#elif (uECC_PLATFORM == uECC_arm_thumb) + #warning uECC_arm_thumb +#elif (uECC_PLATFORM == uECC_arm_thumb2) + #warning uECC_arm_thumb2 +#endif +#endif + +#if (uECC_PLATFORM == uECC_avr) + #include "asm_avr.inc" +#endif + +#if default_RNG_defined +static uECC_RNG_Function g_rng_function = &default_RNG; +#else +static uECC_RNG_Function g_rng_function = 0; +#endif + +void uECC_set_rng(uECC_RNG_Function rng_function) { + g_rng_function = rng_function; +} + +uECC_RNG_Function uECC_get_rng(void) { + return g_rng_function; +} + +int uECC_curve_private_key_size(uECC_Curve curve) { + return BITS_TO_BYTES(curve->num_n_bits); +} + +int uECC_curve_public_key_size(uECC_Curve curve) { + return 2 * curve->num_bytes; +} + +#if !asm_clear +uECC_VLI_API void uECC_vli_clear(uECC_word_t *vli, wordcount_t num_words) { + wordcount_t i; + for (i = 0; i < num_words; ++i) { + vli[i] = 0; + } +} +#endif /* !asm_clear */ + +/* Constant-time comparison to zero - secure way to compare long integers */ +/* Returns 1 if vli == 0, 0 otherwise. */ +uECC_VLI_API uECC_word_t uECC_vli_isZero(const uECC_word_t *vli, wordcount_t num_words) { + uECC_word_t bits = 0; + wordcount_t i; + for (i = 0; i < num_words; ++i) { + bits |= vli[i]; + } + return (bits == 0); +} + +/* Returns nonzero if bit 'bit' of vli is set. */ +uECC_VLI_API uECC_word_t uECC_vli_testBit(const uECC_word_t *vli, bitcount_t bit) { + return (vli[bit >> uECC_WORD_BITS_SHIFT] & ((uECC_word_t)1 << (bit & uECC_WORD_BITS_MASK))); +} + +/* Counts the number of words in vli. */ +static wordcount_t vli_numDigits(const uECC_word_t *vli, const wordcount_t max_words) { + wordcount_t i; + /* Search from the end until we find a non-zero digit. + We do it in reverse because we expect that most digits will be nonzero. */ + for (i = max_words - 1; i >= 0 && vli[i] == 0; --i) { + } + + return (i + 1); +} + +/* Counts the number of bits required to represent vli. */ +uECC_VLI_API bitcount_t uECC_vli_numBits(const uECC_word_t *vli, const wordcount_t max_words) { + uECC_word_t i; + uECC_word_t digit; + + wordcount_t num_digits = vli_numDigits(vli, max_words); + if (num_digits == 0) { + return 0; + } + + digit = vli[num_digits - 1]; + for (i = 0; digit; ++i) { + digit >>= 1; + } + + return (((bitcount_t)(num_digits - 1) << uECC_WORD_BITS_SHIFT) + i); +} + +/* Sets dest = src. */ +#if !asm_set +uECC_VLI_API void uECC_vli_set(uECC_word_t *dest, const uECC_word_t *src, wordcount_t num_words) { + wordcount_t i; + for (i = 0; i < num_words; ++i) { + dest[i] = src[i]; + } +} +#endif /* !asm_set */ + +/* Returns sign of left - right. */ +static cmpresult_t uECC_vli_cmp_unsafe(const uECC_word_t *left, + const uECC_word_t *right, + wordcount_t num_words) { + wordcount_t i; + for (i = num_words - 1; i >= 0; --i) { + if (left[i] > right[i]) { + return 1; + } else if (left[i] < right[i]) { + return -1; + } + } + return 0; +} + +/* Constant-time comparison function - secure way to compare long integers */ +/* Returns one if left == right, zero otherwise. */ +uECC_VLI_API uECC_word_t uECC_vli_equal(const uECC_word_t *left, + const uECC_word_t *right, + wordcount_t num_words) { + uECC_word_t diff = 0; + wordcount_t i; + for (i = num_words - 1; i >= 0; --i) { + diff |= (left[i] ^ right[i]); + } + return (diff == 0); +} + +uECC_VLI_API uECC_word_t uECC_vli_sub(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + wordcount_t num_words); + +/* Returns sign of left - right, in constant time. */ +uECC_VLI_API cmpresult_t uECC_vli_cmp(const uECC_word_t *left, + const uECC_word_t *right, + wordcount_t num_words) { + uECC_word_t tmp[uECC_MAX_WORDS]; + uECC_word_t neg = !!uECC_vli_sub(tmp, left, right, num_words); + uECC_word_t equal = uECC_vli_isZero(tmp, num_words); + return (!equal - 2 * neg); +} + +/* Computes vli = vli >> 1. */ +#if !asm_rshift1 +uECC_VLI_API void uECC_vli_rshift1(uECC_word_t *vli, wordcount_t num_words) { + uECC_word_t *end = vli; + uECC_word_t carry = 0; + + vli += num_words; + while (vli-- > end) { + uECC_word_t temp = *vli; + *vli = (temp >> 1) | carry; + carry = temp << (uECC_WORD_BITS - 1); + } +} +#endif /* !asm_rshift1 */ + +/* Computes result = left + right, returning carry. Can modify in place. */ +#if !asm_add +uECC_VLI_API uECC_word_t uECC_vli_add(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + wordcount_t num_words) { + uECC_word_t carry = 0; + wordcount_t i; + for (i = 0; i < num_words; ++i) { + uECC_word_t sum = left[i] + right[i] + carry; + if (sum != left[i]) { + carry = (sum < left[i]); + } + result[i] = sum; + } + return carry; +} +#endif /* !asm_add */ + +/* Computes result = left - right, returning borrow. Can modify in place. */ +#if !asm_sub +uECC_VLI_API uECC_word_t uECC_vli_sub(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + wordcount_t num_words) { + uECC_word_t borrow = 0; + wordcount_t i; + for (i = 0; i < num_words; ++i) { + uECC_word_t diff = left[i] - right[i] - borrow; + if (diff != left[i]) { + borrow = (diff > left[i]); + } + result[i] = diff; + } + return borrow; +} +#endif /* !asm_sub */ + +#if !asm_mult || (uECC_SQUARE_FUNC && !asm_square) || \ + (uECC_SUPPORTS_secp256k1 && (uECC_OPTIMIZATION_LEVEL > 0) && \ + ((uECC_WORD_SIZE == 1) || (uECC_WORD_SIZE == 8))) +static void muladd(uECC_word_t a, + uECC_word_t b, + uECC_word_t *r0, + uECC_word_t *r1, + uECC_word_t *r2) { +#if uECC_WORD_SIZE == 8 && !SUPPORTS_INT128 + uint64_t a0 = a & 0xffffffffull; + uint64_t a1 = a >> 32; + uint64_t b0 = b & 0xffffffffull; + uint64_t b1 = b >> 32; + + uint64_t i0 = a0 * b0; + uint64_t i1 = a0 * b1; + uint64_t i2 = a1 * b0; + uint64_t i3 = a1 * b1; + + uint64_t p0, p1; + + i2 += (i0 >> 32); + i2 += i1; + if (i2 < i1) { /* overflow */ + i3 += 0x100000000ull; + } + + p0 = (i0 & 0xffffffffull) | (i2 << 32); + p1 = i3 + (i2 >> 32); + + *r0 += p0; + *r1 += (p1 + (*r0 < p0)); + *r2 += ((*r1 < p1) || (*r1 == p1 && *r0 < p0)); +#else + uECC_dword_t p = (uECC_dword_t)a * b; + uECC_dword_t r01 = ((uECC_dword_t)(*r1) << uECC_WORD_BITS) | *r0; + r01 += p; + *r2 += (r01 < p); + *r1 = r01 >> uECC_WORD_BITS; + *r0 = (uECC_word_t)r01; +#endif +} +#endif /* muladd needed */ + +#if !asm_mult +uECC_VLI_API void uECC_vli_mult(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + wordcount_t num_words) { + uECC_word_t r0 = 0; + uECC_word_t r1 = 0; + uECC_word_t r2 = 0; + wordcount_t i, k; + + /* Compute each digit of result in sequence, maintaining the carries. */ + for (k = 0; k < num_words; ++k) { + for (i = 0; i <= k; ++i) { + muladd(left[i], right[k - i], &r0, &r1, &r2); + } + result[k] = r0; + r0 = r1; + r1 = r2; + r2 = 0; + } + for (k = num_words; k < num_words * 2 - 1; ++k) { + for (i = (k + 1) - num_words; i < num_words; ++i) { + muladd(left[i], right[k - i], &r0, &r1, &r2); + } + result[k] = r0; + r0 = r1; + r1 = r2; + r2 = 0; + } + result[num_words * 2 - 1] = r0; +} +#endif /* !asm_mult */ + +#if uECC_SQUARE_FUNC + +#if !asm_square +static void mul2add(uECC_word_t a, + uECC_word_t b, + uECC_word_t *r0, + uECC_word_t *r1, + uECC_word_t *r2) { +#if uECC_WORD_SIZE == 8 && !SUPPORTS_INT128 + uint64_t a0 = a & 0xffffffffull; + uint64_t a1 = a >> 32; + uint64_t b0 = b & 0xffffffffull; + uint64_t b1 = b >> 32; + + uint64_t i0 = a0 * b0; + uint64_t i1 = a0 * b1; + uint64_t i2 = a1 * b0; + uint64_t i3 = a1 * b1; + + uint64_t p0, p1; + + i2 += (i0 >> 32); + i2 += i1; + if (i2 < i1) + { /* overflow */ + i3 += 0x100000000ull; + } + + p0 = (i0 & 0xffffffffull) | (i2 << 32); + p1 = i3 + (i2 >> 32); + + *r2 += (p1 >> 63); + p1 = (p1 << 1) | (p0 >> 63); + p0 <<= 1; + + *r0 += p0; + *r1 += (p1 + (*r0 < p0)); + *r2 += ((*r1 < p1) || (*r1 == p1 && *r0 < p0)); +#else + uECC_dword_t p = (uECC_dword_t)a * b; + uECC_dword_t r01 = ((uECC_dword_t)(*r1) << uECC_WORD_BITS) | *r0; + *r2 += (p >> (uECC_WORD_BITS * 2 - 1)); + p *= 2; + r01 += p; + *r2 += (r01 < p); + *r1 = r01 >> uECC_WORD_BITS; + *r0 = (uECC_word_t)r01; +#endif +} + +uECC_VLI_API void uECC_vli_square(uECC_word_t *result, + const uECC_word_t *left, + wordcount_t num_words) { + uECC_word_t r0 = 0; + uECC_word_t r1 = 0; + uECC_word_t r2 = 0; + + wordcount_t i, k; + + for (k = 0; k < num_words * 2 - 1; ++k) { + uECC_word_t min = (k < num_words ? 0 : (k + 1) - num_words); + for (i = min; i <= k && i <= k - i; ++i) { + if (i < k-i) { + mul2add(left[i], left[k - i], &r0, &r1, &r2); + } else { + muladd(left[i], left[k - i], &r0, &r1, &r2); + } + } + result[k] = r0; + r0 = r1; + r1 = r2; + r2 = 0; + } + + result[num_words * 2 - 1] = r0; +} +#endif /* !asm_square */ + +#else /* uECC_SQUARE_FUNC */ + +#if uECC_ENABLE_VLI_API +uECC_VLI_API void uECC_vli_square(uECC_word_t *result, + const uECC_word_t *left, + wordcount_t num_words) { + uECC_vli_mult(result, left, left, num_words); +} +#endif /* uECC_ENABLE_VLI_API */ + +#endif /* uECC_SQUARE_FUNC */ + +/* Computes result = (left + right) % mod. + Assumes that left < mod and right < mod, and that result does not overlap mod. */ +uECC_VLI_API void uECC_vli_modAdd(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + const uECC_word_t *mod, + wordcount_t num_words) { + uECC_word_t carry = uECC_vli_add(result, left, right, num_words); + if (carry || uECC_vli_cmp_unsafe(mod, result, num_words) != 1) { + /* result > mod (result = mod + remainder), so subtract mod to get remainder. */ + uECC_vli_sub(result, result, mod, num_words); + } +} + +/* Computes result = (left - right) % mod. + Assumes that left < mod and right < mod, and that result does not overlap mod. */ +uECC_VLI_API void uECC_vli_modSub(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + const uECC_word_t *mod, + wordcount_t num_words) { + uECC_word_t l_borrow = uECC_vli_sub(result, left, right, num_words); + if (l_borrow) { + /* In this case, result == -diff == (max int) - diff. Since -x % d == d - x, + we can get the correct result from result + mod (with overflow). */ + uECC_vli_add(result, result, mod, num_words); + } +} + +/* Computes result = product % mod, where product is 2N words long. */ +/* Currently only designed to work for curve_p or curve_n. */ +uECC_VLI_API void uECC_vli_mmod(uECC_word_t *result, + uECC_word_t *product, + const uECC_word_t *mod, + wordcount_t num_words) { + uECC_word_t mod_multiple[2 * uECC_MAX_WORDS]; + uECC_word_t tmp[2 * uECC_MAX_WORDS]; + uECC_word_t *v[2] = {tmp, product}; + uECC_word_t index; + + /* Shift mod so its highest set bit is at the maximum position. */ + bitcount_t shift = (num_words * 2 * uECC_WORD_BITS) - uECC_vli_numBits(mod, num_words); + wordcount_t word_shift = shift / uECC_WORD_BITS; + wordcount_t bit_shift = shift % uECC_WORD_BITS; + uECC_word_t carry = 0; + uECC_vli_clear(mod_multiple, word_shift); + if (bit_shift > 0) { + for(index = 0; index < (uECC_word_t)num_words; ++index) { + mod_multiple[word_shift + index] = (mod[index] << bit_shift) | carry; + carry = mod[index] >> (uECC_WORD_BITS - bit_shift); + } + } else { + uECC_vli_set(mod_multiple + word_shift, mod, num_words); + } + + for (index = 1; shift >= 0; --shift) { + uECC_word_t borrow = 0; + wordcount_t i; + for (i = 0; i < num_words * 2; ++i) { + uECC_word_t diff = v[index][i] - mod_multiple[i] - borrow; + if (diff != v[index][i]) { + borrow = (diff > v[index][i]); + } + v[1 - index][i] = diff; + } + index = !(index ^ borrow); /* Swap the index if there was no borrow */ + uECC_vli_rshift1(mod_multiple, num_words); + mod_multiple[num_words - 1] |= mod_multiple[num_words] << (uECC_WORD_BITS - 1); + uECC_vli_rshift1(mod_multiple + num_words, num_words); + } + uECC_vli_set(result, v[index], num_words); +} + +/* Computes result = (left * right) % mod. */ +uECC_VLI_API void uECC_vli_modMult(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + const uECC_word_t *mod, + wordcount_t num_words) { + uECC_word_t product[2 * uECC_MAX_WORDS]; + uECC_vli_mult(product, left, right, num_words); + uECC_vli_mmod(result, product, mod, num_words); +} + +uECC_VLI_API void uECC_vli_modMult_fast(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + uECC_Curve curve) { + uECC_word_t product[2 * uECC_MAX_WORDS]; + uECC_vli_mult(product, left, right, curve->num_words); +#if (uECC_OPTIMIZATION_LEVEL > 0) + curve->mmod_fast(result, product); +#else + uECC_vli_mmod(result, product, curve->p, curve->num_words); +#endif +} + +#if uECC_SQUARE_FUNC + +#if uECC_ENABLE_VLI_API +/* Computes result = left^2 % mod. */ +uECC_VLI_API void uECC_vli_modSquare(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *mod, + wordcount_t num_words) { + uECC_word_t product[2 * uECC_MAX_WORDS]; + uECC_vli_square(product, left, num_words); + uECC_vli_mmod(result, product, mod, num_words); +} +#endif /* uECC_ENABLE_VLI_API */ + +uECC_VLI_API void uECC_vli_modSquare_fast(uECC_word_t *result, + const uECC_word_t *left, + uECC_Curve curve) { + uECC_word_t product[2 * uECC_MAX_WORDS]; + uECC_vli_square(product, left, curve->num_words); +#if (uECC_OPTIMIZATION_LEVEL > 0) + curve->mmod_fast(result, product); +#else + uECC_vli_mmod(result, product, curve->p, curve->num_words); +#endif +} + +#else /* uECC_SQUARE_FUNC */ + +#if uECC_ENABLE_VLI_API +uECC_VLI_API void uECC_vli_modSquare(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *mod, + wordcount_t num_words) { + uECC_vli_modMult(result, left, left, mod, num_words); +} +#endif /* uECC_ENABLE_VLI_API */ + +uECC_VLI_API void uECC_vli_modSquare_fast(uECC_word_t *result, + const uECC_word_t *left, + uECC_Curve curve) { + uECC_vli_modMult_fast(result, left, left, curve); +} + +#endif /* uECC_SQUARE_FUNC */ + +#define EVEN(vli) (!(vli[0] & 1)) +static void vli_modInv_update(uECC_word_t *uv, + const uECC_word_t *mod, + wordcount_t num_words) { + uECC_word_t carry = 0; + if (!EVEN(uv)) { + carry = uECC_vli_add(uv, uv, mod, num_words); + } + uECC_vli_rshift1(uv, num_words); + if (carry) { + uv[num_words - 1] |= HIGH_BIT_SET; + } +} + +/* Computes result = (1 / input) % mod. All VLIs are the same size. + See "From Euclid's GCD to Montgomery Multiplication to the Great Divide" */ +uECC_VLI_API void uECC_vli_modInv(uECC_word_t *result, + const uECC_word_t *input, + const uECC_word_t *mod, + wordcount_t num_words) { + uECC_word_t a[uECC_MAX_WORDS], b[uECC_MAX_WORDS], u[uECC_MAX_WORDS], v[uECC_MAX_WORDS]; + cmpresult_t cmpResult; + + if (uECC_vli_isZero(input, num_words)) { + uECC_vli_clear(result, num_words); + return; + } + + uECC_vli_set(a, input, num_words); + uECC_vli_set(b, mod, num_words); + uECC_vli_clear(u, num_words); + u[0] = 1; + uECC_vli_clear(v, num_words); + while ((cmpResult = uECC_vli_cmp_unsafe(a, b, num_words)) != 0) { + if (EVEN(a)) { + uECC_vli_rshift1(a, num_words); + vli_modInv_update(u, mod, num_words); + } else if (EVEN(b)) { + uECC_vli_rshift1(b, num_words); + vli_modInv_update(v, mod, num_words); + } else if (cmpResult > 0) { + uECC_vli_sub(a, a, b, num_words); + uECC_vli_rshift1(a, num_words); + if (uECC_vli_cmp_unsafe(u, v, num_words) < 0) { + uECC_vli_add(u, u, mod, num_words); + } + uECC_vli_sub(u, u, v, num_words); + vli_modInv_update(u, mod, num_words); + } else { + uECC_vli_sub(b, b, a, num_words); + uECC_vli_rshift1(b, num_words); + if (uECC_vli_cmp_unsafe(v, u, num_words) < 0) { + uECC_vli_add(v, v, mod, num_words); + } + uECC_vli_sub(v, v, u, num_words); + vli_modInv_update(v, mod, num_words); + } + } + uECC_vli_set(result, u, num_words); +} + +/* ------ Point operations ------ */ + +//#include "curve-specific.inc" +#include "curve-specific.h" + +/* Returns 1 if 'point' is the point at infinity, 0 otherwise. */ +#define EccPoint_isZero(point, curve) uECC_vli_isZero((point), (curve)->num_words * 2) + +/* Point multiplication algorithm using Montgomery's ladder with co-Z coordinates. +From http://eprint.iacr.org/2011/338.pdf +*/ + +/* Modify (x1, y1) => (x1 * z^2, y1 * z^3) */ +static void apply_z(uECC_word_t * X1, + uECC_word_t * Y1, + const uECC_word_t * const Z, + uECC_Curve curve) { + uECC_word_t t1[uECC_MAX_WORDS]; + + uECC_vli_modSquare_fast(t1, Z, curve); /* z^2 */ + uECC_vli_modMult_fast(X1, X1, t1, curve); /* x1 * z^2 */ + uECC_vli_modMult_fast(t1, t1, Z, curve); /* z^3 */ + uECC_vli_modMult_fast(Y1, Y1, t1, curve); /* y1 * z^3 */ +} + +/* P = (x1, y1) => 2P, (x2, y2) => P' */ +static void XYcZ_initial_double(uECC_word_t * X1, + uECC_word_t * Y1, + uECC_word_t * X2, + uECC_word_t * Y2, + const uECC_word_t * const initial_Z, + uECC_Curve curve) { + uECC_word_t z[uECC_MAX_WORDS]; + wordcount_t num_words = curve->num_words; + if (initial_Z) { + uECC_vli_set(z, initial_Z, num_words); + } else { + uECC_vli_clear(z, num_words); + z[0] = 1; + } + + uECC_vli_set(X2, X1, num_words); + uECC_vli_set(Y2, Y1, num_words); + + apply_z(X1, Y1, z, curve); + curve->double_jacobian(X1, Y1, z, curve); + apply_z(X2, Y2, z, curve); +} + +/* Input P = (x1, y1, Z), Q = (x2, y2, Z) + Output P' = (x1', y1', Z3), P + Q = (x3, y3, Z3) + or P => P', Q => P + Q +*/ +static void XYcZ_add(uECC_word_t * X1, + uECC_word_t * Y1, + uECC_word_t * X2, + uECC_word_t * Y2, + uECC_Curve curve) { + /* t1 = X1, t2 = Y1, t3 = X2, t4 = Y2 */ + uECC_word_t t5[uECC_MAX_WORDS]; + wordcount_t num_words = curve->num_words; + + uECC_vli_modSub(t5, X2, X1, curve->p, num_words); /* t5 = x2 - x1 */ + uECC_vli_modSquare_fast(t5, t5, curve); /* t5 = (x2 - x1)^2 = A */ + uECC_vli_modMult_fast(X1, X1, t5, curve); /* t1 = x1*A = B */ + uECC_vli_modMult_fast(X2, X2, t5, curve); /* t3 = x2*A = C */ + uECC_vli_modSub(Y2, Y2, Y1, curve->p, num_words); /* t4 = y2 - y1 */ + uECC_vli_modSquare_fast(t5, Y2, curve); /* t5 = (y2 - y1)^2 = D */ + + uECC_vli_modSub(t5, t5, X1, curve->p, num_words); /* t5 = D - B */ + uECC_vli_modSub(t5, t5, X2, curve->p, num_words); /* t5 = D - B - C = x3 */ + uECC_vli_modSub(X2, X2, X1, curve->p, num_words); /* t3 = C - B */ + uECC_vli_modMult_fast(Y1, Y1, X2, curve); /* t2 = y1*(C - B) */ + uECC_vli_modSub(X2, X1, t5, curve->p, num_words); /* t3 = B - x3 */ + uECC_vli_modMult_fast(Y2, Y2, X2, curve); /* t4 = (y2 - y1)*(B - x3) */ + uECC_vli_modSub(Y2, Y2, Y1, curve->p, num_words); /* t4 = y3 */ + + uECC_vli_set(X2, t5, num_words); +} + +/* Input P = (x1, y1, Z), Q = (x2, y2, Z) + Output P + Q = (x3, y3, Z3), P - Q = (x3', y3', Z3) + or P => P - Q, Q => P + Q +*/ +static void XYcZ_addC(uECC_word_t * X1, + uECC_word_t * Y1, + uECC_word_t * X2, + uECC_word_t * Y2, + uECC_Curve curve) { + /* t1 = X1, t2 = Y1, t3 = X2, t4 = Y2 */ + uECC_word_t t5[uECC_MAX_WORDS]; + uECC_word_t t6[uECC_MAX_WORDS]; + uECC_word_t t7[uECC_MAX_WORDS]; + wordcount_t num_words = curve->num_words; + + uECC_vli_modSub(t5, X2, X1, curve->p, num_words); /* t5 = x2 - x1 */ + uECC_vli_modSquare_fast(t5, t5, curve); /* t5 = (x2 - x1)^2 = A */ + uECC_vli_modMult_fast(X1, X1, t5, curve); /* t1 = x1*A = B */ + uECC_vli_modMult_fast(X2, X2, t5, curve); /* t3 = x2*A = C */ + uECC_vli_modAdd(t5, Y2, Y1, curve->p, num_words); /* t5 = y2 + y1 */ + uECC_vli_modSub(Y2, Y2, Y1, curve->p, num_words); /* t4 = y2 - y1 */ + + uECC_vli_modSub(t6, X2, X1, curve->p, num_words); /* t6 = C - B */ + uECC_vli_modMult_fast(Y1, Y1, t6, curve); /* t2 = y1 * (C - B) = E */ + uECC_vli_modAdd(t6, X1, X2, curve->p, num_words); /* t6 = B + C */ + uECC_vli_modSquare_fast(X2, Y2, curve); /* t3 = (y2 - y1)^2 = D */ + uECC_vli_modSub(X2, X2, t6, curve->p, num_words); /* t3 = D - (B + C) = x3 */ + + uECC_vli_modSub(t7, X1, X2, curve->p, num_words); /* t7 = B - x3 */ + uECC_vli_modMult_fast(Y2, Y2, t7, curve); /* t4 = (y2 - y1)*(B - x3) */ + uECC_vli_modSub(Y2, Y2, Y1, curve->p, num_words); /* t4 = (y2 - y1)*(B - x3) - E = y3 */ + + uECC_vli_modSquare_fast(t7, t5, curve); /* t7 = (y2 + y1)^2 = F */ + uECC_vli_modSub(t7, t7, t6, curve->p, num_words); /* t7 = F - (B + C) = x3' */ + uECC_vli_modSub(t6, t7, X1, curve->p, num_words); /* t6 = x3' - B */ + uECC_vli_modMult_fast(t6, t6, t5, curve); /* t6 = (y2+y1)*(x3' - B) */ + uECC_vli_modSub(Y1, t6, Y1, curve->p, num_words); /* t2 = (y2+y1)*(x3' - B) - E = y3' */ + + uECC_vli_set(X1, t7, num_words); +} + +/* result may overlap point. */ +static void EccPoint_mult(uECC_word_t * result, + const uECC_word_t * point, + const uECC_word_t * scalar, + const uECC_word_t * initial_Z, + bitcount_t num_bits, + uECC_Curve curve) { + /* R0 and R1 */ + uECC_word_t Rx[2][uECC_MAX_WORDS]; + uECC_word_t Ry[2][uECC_MAX_WORDS]; + uECC_word_t z[uECC_MAX_WORDS]; + bitcount_t i; + uECC_word_t nb; + wordcount_t num_words = curve->num_words; + + uECC_vli_set(Rx[1], point, num_words); + uECC_vli_set(Ry[1], point + num_words, num_words); + + XYcZ_initial_double(Rx[1], Ry[1], Rx[0], Ry[0], initial_Z, curve); + + for (i = num_bits - 2; i > 0; --i) { + nb = !uECC_vli_testBit(scalar, i); + XYcZ_addC(Rx[1 - nb], Ry[1 - nb], Rx[nb], Ry[nb], curve); + XYcZ_add(Rx[nb], Ry[nb], Rx[1 - nb], Ry[1 - nb], curve); + } + + nb = !uECC_vli_testBit(scalar, 0); + XYcZ_addC(Rx[1 - nb], Ry[1 - nb], Rx[nb], Ry[nb], curve); + + /* Find final 1/Z value. */ + uECC_vli_modSub(z, Rx[1], Rx[0], curve->p, num_words); /* X1 - X0 */ + uECC_vli_modMult_fast(z, z, Ry[1 - nb], curve); /* Yb * (X1 - X0) */ + uECC_vli_modMult_fast(z, z, point, curve); /* xP * Yb * (X1 - X0) */ + uECC_vli_modInv(z, z, curve->p, num_words); /* 1 / (xP * Yb * (X1 - X0)) */ + /* yP / (xP * Yb * (X1 - X0)) */ + uECC_vli_modMult_fast(z, z, point + num_words, curve); + uECC_vli_modMult_fast(z, z, Rx[1 - nb], curve); /* Xb * yP / (xP * Yb * (X1 - X0)) */ + /* End 1/Z calculation */ + + XYcZ_add(Rx[nb], Ry[nb], Rx[1 - nb], Ry[1 - nb], curve); + apply_z(Rx[0], Ry[0], z, curve); + + uECC_vli_set(result, Rx[0], num_words); + uECC_vli_set(result + num_words, Ry[0], num_words); +} + +static uECC_word_t regularize_k(const uECC_word_t * const k, + uECC_word_t *k0, + uECC_word_t *k1, + uECC_Curve curve) { + wordcount_t num_n_words = BITS_TO_WORDS(curve->num_n_bits); + bitcount_t num_n_bits = curve->num_n_bits; + uECC_word_t carry = uECC_vli_add(k0, k, curve->n, num_n_words) || + (num_n_bits < ((bitcount_t)num_n_words * uECC_WORD_SIZE * 8) && + uECC_vli_testBit(k0, num_n_bits)); + uECC_vli_add(k1, k0, curve->n, num_n_words); + return carry; +} + +static uECC_word_t EccPoint_compute_public_key(uECC_word_t *result, + uECC_word_t *private_key, + uECC_Curve curve) { + uECC_word_t tmp1[uECC_MAX_WORDS]; + uECC_word_t tmp2[uECC_MAX_WORDS]; + uECC_word_t *p2[2] = {tmp1, tmp2}; + uECC_word_t carry; + + /* Regularize the bitcount for the private key so that attackers cannot use a side channel + attack to learn the number of leading zeros. */ + carry = regularize_k(private_key, tmp1, tmp2, curve); + + EccPoint_mult(result, curve->G, p2[!carry], 0, curve->num_n_bits + 1, curve); + + if (EccPoint_isZero(result, curve)) { + return 0; + } + return 1; +} + +#if uECC_WORD_SIZE == 1 + +uECC_VLI_API void uECC_vli_nativeToBytes(uint8_t *bytes, + int num_bytes, + const uint8_t *native) { + wordcount_t i; + for (i = 0; i < num_bytes; ++i) { + bytes[i] = native[(num_bytes - 1) - i]; + } +} + +uECC_VLI_API void uECC_vli_bytesToNative(uint8_t *native, + const uint8_t *bytes, + int num_bytes) { + uECC_vli_nativeToBytes(native, num_bytes, bytes); +} + +#else + +uECC_VLI_API void uECC_vli_nativeToBytes(uint8_t *bytes, + int num_bytes, + const uECC_word_t *native) { + wordcount_t i; + for (i = 0; i < num_bytes; ++i) { + unsigned b = num_bytes - 1 - i; + bytes[i] = native[b / uECC_WORD_SIZE] >> (8 * (b % uECC_WORD_SIZE)); + } +} + +uECC_VLI_API void uECC_vli_bytesToNative(uECC_word_t *native, + const uint8_t *bytes, + int num_bytes) { + wordcount_t i; + uECC_vli_clear(native, (num_bytes + (uECC_WORD_SIZE - 1)) / uECC_WORD_SIZE); + for (i = 0; i < num_bytes; ++i) { + unsigned b = num_bytes - 1 - i; + native[b / uECC_WORD_SIZE] |= + (uECC_word_t)bytes[i] << (8 * (b % uECC_WORD_SIZE)); + } +} + +#endif /* uECC_WORD_SIZE */ + +/* Generates a random integer in the range 0 < random < top. + Both random and top have num_words words. */ +uECC_VLI_API int uECC_generate_random_int(uECC_word_t *random, + const uECC_word_t *top, + wordcount_t num_words) { + uECC_word_t mask = (uECC_word_t)-1; + uECC_word_t tries; + bitcount_t num_bits = uECC_vli_numBits(top, num_words); + + if (!g_rng_function) { + return 0; + } + + for (tries = 0; tries < uECC_RNG_MAX_TRIES; ++tries) { + if (!g_rng_function((uint8_t *)random, num_words * uECC_WORD_SIZE)) { + return 0; + } + random[num_words - 1] &= mask >> ((bitcount_t)(num_words * uECC_WORD_SIZE * 8 - num_bits)); + if (!uECC_vli_isZero(random, num_words) && + uECC_vli_cmp(top, random, num_words) == 1) { + return 1; + } + } + return 0; +} + +int uECC_make_key(uint8_t *public_key, + uint8_t *private_key, + uECC_Curve curve) { +#if uECC_VLI_NATIVE_LITTLE_ENDIAN + uECC_word_t *_private = (uECC_word_t *)private_key; + uECC_word_t *_public = (uECC_word_t *)public_key; +#else + uECC_word_t _private[uECC_MAX_WORDS]; + uECC_word_t _public[uECC_MAX_WORDS * 2]; +#endif + uECC_word_t tries; + + for (tries = 0; tries < uECC_RNG_MAX_TRIES; ++tries) { + if (!uECC_generate_random_int(_private, curve->n, BITS_TO_WORDS(curve->num_n_bits))) { + return 0; + } + + if (EccPoint_compute_public_key(_public, _private, curve)) { +#if uECC_VLI_NATIVE_LITTLE_ENDIAN == 0 + uECC_vli_nativeToBytes(private_key, BITS_TO_BYTES(curve->num_n_bits), _private); + uECC_vli_nativeToBytes(public_key, curve->num_bytes, _public); + uECC_vli_nativeToBytes( + public_key + curve->num_bytes, curve->num_bytes, _public + curve->num_words); +#endif + return 1; + } + } + return 0; +} + +int uECC_shared_secret(const uint8_t *public_key, + const uint8_t *private_key, + uint8_t *secret, + uECC_Curve curve) { + uECC_word_t _public[uECC_MAX_WORDS * 2]; + uECC_word_t _private[uECC_MAX_WORDS]; + + uECC_word_t tmp[uECC_MAX_WORDS]; + uECC_word_t *p2[2] = {_private, tmp}; + uECC_word_t *initial_Z = 0; + uECC_word_t carry; + wordcount_t num_words = curve->num_words; + wordcount_t num_bytes = curve->num_bytes; + +#if uECC_VLI_NATIVE_LITTLE_ENDIAN + bcopy((uint8_t *) _private, private_key, num_bytes); + bcopy((uint8_t *) _public, public_key, num_bytes*2); +#else + uECC_vli_bytesToNative(_private, private_key, BITS_TO_BYTES(curve->num_n_bits)); + uECC_vli_bytesToNative(_public, public_key, num_bytes); + uECC_vli_bytesToNative(_public + num_words, public_key + num_bytes, num_bytes); +#endif + + /* Regularize the bitcount for the private key so that attackers cannot use a side channel + attack to learn the number of leading zeros. */ + carry = regularize_k(_private, _private, tmp, curve); + + /* If an RNG function was specified, try to get a random initial Z value to improve + protection against side-channel attacks. */ + if (g_rng_function) { + if (!uECC_generate_random_int(p2[carry], curve->p, num_words)) { + return 0; + } + initial_Z = p2[carry]; + } + + EccPoint_mult(_public, _public, p2[!carry], initial_Z, curve->num_n_bits + 1, curve); +#if uECC_VLI_NATIVE_LITTLE_ENDIAN + bcopy((uint8_t *) secret, (uint8_t *) _public, num_bytes); +#else + uECC_vli_nativeToBytes(secret, num_bytes, _public); +#endif + return !EccPoint_isZero(_public, curve); +} + +#if uECC_SUPPORT_COMPRESSED_POINT +void uECC_compress(const uint8_t *public_key, uint8_t *compressed, uECC_Curve curve) { + wordcount_t i; + for (i = 0; i < curve->num_bytes; ++i) { + compressed[i+1] = public_key[i]; + } +#if uECC_VLI_NATIVE_LITTLE_ENDIAN + compressed[0] = 2 + (public_key[curve->num_bytes] & 0x01); +#else + compressed[0] = 2 + (public_key[curve->num_bytes * 2 - 1] & 0x01); +#endif +} + +void uECC_decompress(const uint8_t *compressed, uint8_t *public_key, uECC_Curve curve) { +#if uECC_VLI_NATIVE_LITTLE_ENDIAN + uECC_word_t *point = (uECC_word_t *)public_key; +#else + uECC_word_t point[uECC_MAX_WORDS * 2]; +#endif + uECC_word_t *y = point + curve->num_words; +#if uECC_VLI_NATIVE_LITTLE_ENDIAN + bcopy(public_key, compressed+1, curve->num_bytes); +#else + uECC_vli_bytesToNative(point, compressed + 1, curve->num_bytes); +#endif + curve->x_side(y, point, curve); + curve->mod_sqrt(y, curve); + + if ((y[0] & 0x01) != (compressed[0] & 0x01)) { + uECC_vli_sub(y, curve->p, y, curve->num_words); + } + +#if uECC_VLI_NATIVE_LITTLE_ENDIAN == 0 + uECC_vli_nativeToBytes(public_key, curve->num_bytes, point); + uECC_vli_nativeToBytes(public_key + curve->num_bytes, curve->num_bytes, y); +#endif +} +#endif /* uECC_SUPPORT_COMPRESSED_POINT */ + +int uECC_valid_point(const uECC_word_t *point, uECC_Curve curve) { + uECC_word_t tmp1[uECC_MAX_WORDS]; + uECC_word_t tmp2[uECC_MAX_WORDS]; + wordcount_t num_words = curve->num_words; + + /* The point at infinity is invalid. */ + if (EccPoint_isZero(point, curve)) { + return 0; + } + + /* x and y must be smaller than p. */ + if (uECC_vli_cmp_unsafe(curve->p, point, num_words) != 1 || + uECC_vli_cmp_unsafe(curve->p, point + num_words, num_words) != 1) { + return 0; + } + + uECC_vli_modSquare_fast(tmp1, point + num_words, curve); + curve->x_side(tmp2, point, curve); /* tmp2 = x^3 + ax + b */ + + /* Make sure that y^2 == x^3 + ax + b */ + return (int)(uECC_vli_equal(tmp1, tmp2, num_words)); +} + +int uECC_valid_public_key(const uint8_t *public_key, uECC_Curve curve) { +#if uECC_VLI_NATIVE_LITTLE_ENDIAN + uECC_word_t *_public = (uECC_word_t *)public_key; +#else + uECC_word_t _public[uECC_MAX_WORDS * 2]; +#endif + +#if uECC_VLI_NATIVE_LITTLE_ENDIAN == 0 + uECC_vli_bytesToNative(_public, public_key, curve->num_bytes); + uECC_vli_bytesToNative( + _public + curve->num_words, public_key + curve->num_bytes, curve->num_bytes); +#endif + return uECC_valid_point(_public, curve); +} + +int uECC_compute_public_key(const uint8_t *private_key, uint8_t *public_key, uECC_Curve curve) { +#if uECC_VLI_NATIVE_LITTLE_ENDIAN + uECC_word_t *_private = (uECC_word_t *)private_key; + uECC_word_t *_public = (uECC_word_t *)public_key; +#else + uECC_word_t _private[uECC_MAX_WORDS]; + uECC_word_t _public[uECC_MAX_WORDS * 2]; +#endif + +#if uECC_VLI_NATIVE_LITTLE_ENDIAN == 0 + uECC_vli_bytesToNative(_private, private_key, BITS_TO_BYTES(curve->num_n_bits)); +#endif + + /* Make sure the private key is in the range [1, n-1]. */ + if (uECC_vli_isZero(_private, BITS_TO_WORDS(curve->num_n_bits))) { + return 0; + } + + if (uECC_vli_cmp(curve->n, _private, BITS_TO_WORDS(curve->num_n_bits)) != 1) { + return 0; + } + + /* Compute public key. */ + if (!EccPoint_compute_public_key(_public, _private, curve)) { + return 0; + } + +#if uECC_VLI_NATIVE_LITTLE_ENDIAN == 0 + uECC_vli_nativeToBytes(public_key, curve->num_bytes, _public); + uECC_vli_nativeToBytes( + public_key + curve->num_bytes, curve->num_bytes, _public + curve->num_words); +#endif + return 1; +} + + +/* -------- ECDSA code -------- */ + +static void bits2int(uECC_word_t *native, + const uint8_t *bits, + unsigned bits_size, + uECC_Curve curve) { + unsigned num_n_bytes = BITS_TO_BYTES(curve->num_n_bits); + unsigned num_n_words = BITS_TO_WORDS(curve->num_n_bits); + int shift; + uECC_word_t carry; + uECC_word_t *ptr; + + if (bits_size > num_n_bytes) { + bits_size = num_n_bytes; + } + + uECC_vli_clear(native, num_n_words); +#if uECC_VLI_NATIVE_LITTLE_ENDIAN + bcopy((uint8_t *) native, bits, bits_size); +#else + uECC_vli_bytesToNative(native, bits, bits_size); +#endif + if (bits_size * 8 <= (unsigned)curve->num_n_bits) { + return; + } + shift = bits_size * 8 - curve->num_n_bits; + carry = 0; + ptr = native + num_n_words; + while (ptr-- > native) { + uECC_word_t temp = *ptr; + *ptr = (temp >> shift) | carry; + carry = temp << (uECC_WORD_BITS - shift); + } + + /* Reduce mod curve_n */ + if (uECC_vli_cmp_unsafe(curve->n, native, num_n_words) != 1) { + uECC_vli_sub(native, native, curve->n, num_n_words); + } +} + +static int uECC_sign_with_k(const uint8_t *private_key, + const uint8_t *message_hash, + unsigned hash_size, + uECC_word_t *k, + uint8_t *signature, + uECC_Curve curve) { + + uECC_word_t tmp[uECC_MAX_WORDS]; + uECC_word_t s[uECC_MAX_WORDS]; + uECC_word_t *k2[2] = {tmp, s}; +#if uECC_VLI_NATIVE_LITTLE_ENDIAN + uECC_word_t *p = (uECC_word_t *)signature; +#else + uECC_word_t p[uECC_MAX_WORDS * 2]; +#endif + uECC_word_t carry; + wordcount_t num_words = curve->num_words; + wordcount_t num_n_words = BITS_TO_WORDS(curve->num_n_bits); + bitcount_t num_n_bits = curve->num_n_bits; + + /* Make sure 0 < k < curve_n */ + if (uECC_vli_isZero(k, num_words) || uECC_vli_cmp(curve->n, k, num_n_words) != 1) { + return 0; + } + + carry = regularize_k(k, tmp, s, curve); + EccPoint_mult(p, curve->G, k2[!carry], 0, num_n_bits + 1, curve); + if (uECC_vli_isZero(p, num_words)) { + return 0; + } + + /* If an RNG function was specified, get a random number + to prevent side channel analysis of k. */ + if (!g_rng_function) { + uECC_vli_clear(tmp, num_n_words); + tmp[0] = 1; + } else if (!uECC_generate_random_int(tmp, curve->n, num_n_words)) { + return 0; + } + + /* Prevent side channel analysis of uECC_vli_modInv() to determine + bits of k / the private key by premultiplying by a random number */ + uECC_vli_modMult(k, k, tmp, curve->n, num_n_words); /* k' = rand * k */ + uECC_vli_modInv(k, k, curve->n, num_n_words); /* k = 1 / k' */ + uECC_vli_modMult(k, k, tmp, curve->n, num_n_words); /* k = 1 / k */ + +#if uECC_VLI_NATIVE_LITTLE_ENDIAN == 0 + uECC_vli_nativeToBytes(signature, curve->num_bytes, p); /* store r */ +#endif + +#if uECC_VLI_NATIVE_LITTLE_ENDIAN + bcopy((uint8_t *) tmp, private_key, BITS_TO_BYTES(curve->num_n_bits)); +#else + uECC_vli_bytesToNative(tmp, private_key, BITS_TO_BYTES(curve->num_n_bits)); /* tmp = d */ +#endif + + s[num_n_words - 1] = 0; + uECC_vli_set(s, p, num_words); + uECC_vli_modMult(s, tmp, s, curve->n, num_n_words); /* s = r*d */ + + bits2int(tmp, message_hash, hash_size, curve); + uECC_vli_modAdd(s, tmp, s, curve->n, num_n_words); /* s = e + r*d */ + uECC_vli_modMult(s, s, k, curve->n, num_n_words); /* s = (e + r*d) / k */ + if (uECC_vli_numBits(s, num_n_words) > (bitcount_t)curve->num_bytes * 8) { + return 0; + } +#if uECC_VLI_NATIVE_LITTLE_ENDIAN + bcopy((uint8_t *) signature + curve->num_bytes, (uint8_t *) s, curve->num_bytes); +#else + uECC_vli_nativeToBytes(signature + curve->num_bytes, curve->num_bytes, s); +#endif + return 1; +} + +int uECC_sign(const uint8_t *private_key, + const uint8_t *message_hash, + unsigned hash_size, + uint8_t *signature, + uECC_Curve curve) { + uECC_word_t k[uECC_MAX_WORDS]; + uECC_word_t tries; + + for (tries = 0; tries < uECC_RNG_MAX_TRIES; ++tries) { + if (!uECC_generate_random_int(k, curve->n, BITS_TO_WORDS(curve->num_n_bits))) { + return 0; + } + + if (uECC_sign_with_k(private_key, message_hash, hash_size, k, signature, curve)) { + return 1; + } + } + return 0; +} + +/* Compute an HMAC using K as a key (as in RFC 6979). Note that K is always + the same size as the hash result size. */ +static void HMAC_init(const uECC_HashContext *hash_context, const uint8_t *K) { + uint8_t *pad = hash_context->tmp + 2 * hash_context->result_size; + unsigned i; + for (i = 0; i < hash_context->result_size; ++i) + pad[i] = K[i] ^ 0x36; + for (; i < hash_context->block_size; ++i) + pad[i] = 0x36; + + hash_context->init_hash(hash_context); + hash_context->update_hash(hash_context, pad, hash_context->block_size); +} + +static void HMAC_update(const uECC_HashContext *hash_context, + const uint8_t *message, + unsigned message_size) { + hash_context->update_hash(hash_context, message, message_size); +} + +static void HMAC_finish(const uECC_HashContext *hash_context, + const uint8_t *K, + uint8_t *result) { + uint8_t *pad = hash_context->tmp + 2 * hash_context->result_size; + unsigned i; + for (i = 0; i < hash_context->result_size; ++i) + pad[i] = K[i] ^ 0x5c; + for (; i < hash_context->block_size; ++i) + pad[i] = 0x5c; + + hash_context->finish_hash(hash_context, result); + + hash_context->init_hash(hash_context); + hash_context->update_hash(hash_context, pad, hash_context->block_size); + hash_context->update_hash(hash_context, result, hash_context->result_size); + hash_context->finish_hash(hash_context, result); +} + +/* V = HMAC_K(V) */ +static void update_V(const uECC_HashContext *hash_context, uint8_t *K, uint8_t *V) { + HMAC_init(hash_context, K); + HMAC_update(hash_context, V, hash_context->result_size); + HMAC_finish(hash_context, K, V); +} + +/* Deterministic signing, similar to RFC 6979. Differences are: + * We just use H(m) directly rather than bits2octets(H(m)) + (it is not reduced modulo curve_n). + * We generate a value for k (aka T) directly rather than converting endianness. + + Layout of hash_context->tmp: <K> | <V> | (1 byte overlapped 0x00 or 0x01) / <HMAC pad> */ +int uECC_sign_deterministic(const uint8_t *private_key, + const uint8_t *message_hash, + unsigned hash_size, + const uECC_HashContext *hash_context, + uint8_t *signature, + uECC_Curve curve) { + uint8_t *K = hash_context->tmp; + uint8_t *V = K + hash_context->result_size; + wordcount_t num_bytes = curve->num_bytes; + wordcount_t num_n_words = BITS_TO_WORDS(curve->num_n_bits); + bitcount_t num_n_bits = curve->num_n_bits; + uECC_word_t tries; + unsigned i; + for (i = 0; i < hash_context->result_size; ++i) { + V[i] = 0x01; + K[i] = 0; + } + + /* K = HMAC_K(V || 0x00 || int2octets(x) || h(m)) */ + HMAC_init(hash_context, K); + V[hash_context->result_size] = 0x00; + HMAC_update(hash_context, V, hash_context->result_size + 1); + HMAC_update(hash_context, private_key, num_bytes); + HMAC_update(hash_context, message_hash, hash_size); + HMAC_finish(hash_context, K, K); + + update_V(hash_context, K, V); + + /* K = HMAC_K(V || 0x01 || int2octets(x) || h(m)) */ + HMAC_init(hash_context, K); + V[hash_context->result_size] = 0x01; + HMAC_update(hash_context, V, hash_context->result_size + 1); + HMAC_update(hash_context, private_key, num_bytes); + HMAC_update(hash_context, message_hash, hash_size); + HMAC_finish(hash_context, K, K); + + update_V(hash_context, K, V); + + for (tries = 0; tries < uECC_RNG_MAX_TRIES; ++tries) { + uECC_word_t T[uECC_MAX_WORDS]; + uint8_t *T_ptr = (uint8_t *)T; + wordcount_t T_bytes = 0; + for (;;) { + update_V(hash_context, K, V); + for (i = 0; i < hash_context->result_size; ++i) { + T_ptr[T_bytes++] = V[i]; + if (T_bytes >= num_n_words * uECC_WORD_SIZE) { + goto filled; + } + } + } + filled: + if ((bitcount_t)num_n_words * uECC_WORD_SIZE * 8 > num_n_bits) { + uECC_word_t mask = (uECC_word_t)-1; + T[num_n_words - 1] &= + mask >> ((bitcount_t)(num_n_words * uECC_WORD_SIZE * 8 - num_n_bits)); + } + + if (uECC_sign_with_k(private_key, message_hash, hash_size, T, signature, curve)) { + return 1; + } + + /* K = HMAC_K(V || 0x00) */ + HMAC_init(hash_context, K); + V[hash_context->result_size] = 0x00; + HMAC_update(hash_context, V, hash_context->result_size + 1); + HMAC_finish(hash_context, K, K); + + update_V(hash_context, K, V); + } + return 0; +} + +static bitcount_t smax(bitcount_t a, bitcount_t b) { + return (a > b ? a : b); +} + +int uECC_verify(const uint8_t *public_key, + const uint8_t *message_hash, + unsigned hash_size, + const uint8_t *signature, + uECC_Curve curve) { + uECC_word_t u1[uECC_MAX_WORDS], u2[uECC_MAX_WORDS]; + uECC_word_t z[uECC_MAX_WORDS]; + uECC_word_t sum[uECC_MAX_WORDS * 2]; + uECC_word_t rx[uECC_MAX_WORDS]; + uECC_word_t ry[uECC_MAX_WORDS]; + uECC_word_t tx[uECC_MAX_WORDS]; + uECC_word_t ty[uECC_MAX_WORDS]; + uECC_word_t tz[uECC_MAX_WORDS]; + const uECC_word_t *points[4]; + const uECC_word_t *point; + bitcount_t num_bits; + bitcount_t i; +#if uECC_VLI_NATIVE_LITTLE_ENDIAN + uECC_word_t *_public = (uECC_word_t *)public_key; +#else + uECC_word_t _public[uECC_MAX_WORDS * 2]; +#endif + uECC_word_t r[uECC_MAX_WORDS], s[uECC_MAX_WORDS]; + wordcount_t num_words = curve->num_words; + wordcount_t num_n_words = BITS_TO_WORDS(curve->num_n_bits); + + rx[num_n_words - 1] = 0; + r[num_n_words - 1] = 0; + s[num_n_words - 1] = 0; + +#if uECC_VLI_NATIVE_LITTLE_ENDIAN + bcopy((uint8_t *) r, signature, curve->num_bytes); + bcopy((uint8_t *) s, signature + curve->num_bytes, curve->num_bytes); +#else + uECC_vli_bytesToNative(_public, public_key, curve->num_bytes); + uECC_vli_bytesToNative( + _public + num_words, public_key + curve->num_bytes, curve->num_bytes); + uECC_vli_bytesToNative(r, signature, curve->num_bytes); + uECC_vli_bytesToNative(s, signature + curve->num_bytes, curve->num_bytes); +#endif + + /* r, s must not be 0. */ + if (uECC_vli_isZero(r, num_words) || uECC_vli_isZero(s, num_words)) { + return 0; + } + + /* r, s must be < n. */ + if (uECC_vli_cmp_unsafe(curve->n, r, num_n_words) != 1 || + uECC_vli_cmp_unsafe(curve->n, s, num_n_words) != 1) { + return 0; + } + + /* Calculate u1 and u2. */ + uECC_vli_modInv(z, s, curve->n, num_n_words); /* z = 1/s */ + u1[num_n_words - 1] = 0; + bits2int(u1, message_hash, hash_size, curve); + uECC_vli_modMult(u1, u1, z, curve->n, num_n_words); /* u1 = e/s */ + uECC_vli_modMult(u2, r, z, curve->n, num_n_words); /* u2 = r/s */ + + /* Calculate sum = G + Q. */ + uECC_vli_set(sum, _public, num_words); + uECC_vli_set(sum + num_words, _public + num_words, num_words); + uECC_vli_set(tx, curve->G, num_words); + uECC_vli_set(ty, curve->G + num_words, num_words); + uECC_vli_modSub(z, sum, tx, curve->p, num_words); /* z = x2 - x1 */ + XYcZ_add(tx, ty, sum, sum + num_words, curve); + uECC_vli_modInv(z, z, curve->p, num_words); /* z = 1/z */ + apply_z(sum, sum + num_words, z, curve); + + /* Use Shamir's trick to calculate u1*G + u2*Q */ + points[0] = 0; + points[1] = curve->G; + points[2] = _public; + points[3] = sum; + num_bits = smax(uECC_vli_numBits(u1, num_n_words), + uECC_vli_numBits(u2, num_n_words)); + + point = points[(!!uECC_vli_testBit(u1, num_bits - 1)) | + ((!!uECC_vli_testBit(u2, num_bits - 1)) << 1)]; + uECC_vli_set(rx, point, num_words); + uECC_vli_set(ry, point + num_words, num_words); + uECC_vli_clear(z, num_words); + z[0] = 1; + + for (i = num_bits - 2; i >= 0; --i) { + uECC_word_t index; + curve->double_jacobian(rx, ry, z, curve); + + index = (!!uECC_vli_testBit(u1, i)) | ((!!uECC_vli_testBit(u2, i)) << 1); + point = points[index]; + if (point) { + uECC_vli_set(tx, point, num_words); + uECC_vli_set(ty, point + num_words, num_words); + apply_z(tx, ty, z, curve); + uECC_vli_modSub(tz, rx, tx, curve->p, num_words); /* Z = x2 - x1 */ + XYcZ_add(tx, ty, rx, ry, curve); + uECC_vli_modMult_fast(z, z, tz, curve); + } + } + + uECC_vli_modInv(z, z, curve->p, num_words); /* Z = 1/Z */ + apply_z(rx, ry, z, curve); + + /* v = x1 (mod n) */ + if (uECC_vli_cmp_unsafe(curve->n, rx, num_n_words) != 1) { + uECC_vli_sub(rx, rx, curve->n, num_n_words); + } + + /* Accept only if v == r. */ + return (int)(uECC_vli_equal(rx, r, num_words)); +} + +#if uECC_ENABLE_VLI_API + +unsigned uECC_curve_num_words(uECC_Curve curve) { + return curve->num_words; +} + +unsigned uECC_curve_num_bytes(uECC_Curve curve) { + return curve->num_bytes; +} + +unsigned uECC_curve_num_bits(uECC_Curve curve) { + return curve->num_bytes * 8; +} + +unsigned uECC_curve_num_n_words(uECC_Curve curve) { + return BITS_TO_WORDS(curve->num_n_bits); +} + +unsigned uECC_curve_num_n_bytes(uECC_Curve curve) { + return BITS_TO_BYTES(curve->num_n_bits); +} + +unsigned uECC_curve_num_n_bits(uECC_Curve curve) { + return curve->num_n_bits; +} + +const uECC_word_t *uECC_curve_p(uECC_Curve curve) { + return curve->p; +} + +const uECC_word_t *uECC_curve_n(uECC_Curve curve) { + return curve->n; +} + +const uECC_word_t *uECC_curve_G(uECC_Curve curve) { + return curve->G; +} + +const uECC_word_t *uECC_curve_b(uECC_Curve curve) { + return curve->b; +} + +#if uECC_SUPPORT_COMPRESSED_POINT +void uECC_vli_mod_sqrt(uECC_word_t *a, uECC_Curve curve) { + curve->mod_sqrt(a, curve); +} +#endif + +void uECC_vli_mmod_fast(uECC_word_t *result, uECC_word_t *product, uECC_Curve curve) { +#if (uECC_OPTIMIZATION_LEVEL > 0) + curve->mmod_fast(result, product); +#else + uECC_vli_mmod(result, product, curve->p, curve->num_words); +#endif +} + +void uECC_point_mult(uECC_word_t *result, + const uECC_word_t *point, + const uECC_word_t *scalar, + uECC_Curve curve) { + uECC_word_t tmp1[uECC_MAX_WORDS]; + uECC_word_t tmp2[uECC_MAX_WORDS]; + uECC_word_t *p2[2] = {tmp1, tmp2}; + uECC_word_t carry = regularize_k(scalar, tmp1, tmp2, curve); + + EccPoint_mult(result, point, p2[!carry], 0, curve->num_n_bits + 1, curve); +} + +#endif /* uECC_ENABLE_VLI_API */
diff -r 000000000000 -r b6fdeddc0bc9 uECC.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/uECC.h Thu Sep 07 12:10:11 2017 +0000 @@ -0,0 +1,368 @@ +/* Copyright 2014, Kenneth MacKay. Licensed under the BSD 2-clause license. */ + +#ifndef _UECC_H_ +#define _UECC_H_ + +#include <stdint.h> + +/* Platform selection options. +If uECC_PLATFORM is not defined, the code will try to guess it based on compiler macros. +Possible values for uECC_PLATFORM are defined below: */ +#define uECC_arch_other 0 +#define uECC_x86 1 +#define uECC_x86_64 2 +#define uECC_arm 3 +#define uECC_arm_thumb 4 +#define uECC_arm_thumb2 5 +#define uECC_arm64 6 +#define uECC_avr 7 + +/* Defined arch to others to allow mbed compiler go through building first */ +#define uECC_PLATFORM uECC_arch_other + +/* If desired, you can define uECC_WORD_SIZE as appropriate for your platform (1, 4, or 8 bytes). +If uECC_WORD_SIZE is not explicitly defined then it will be automatically set based on your +platform. */ + +/* Optimization level; trade speed for code size. + Larger values produce code that is faster but larger. + Currently supported values are 0 - 4; 0 is unusably slow for most applications. + Optimization level 4 currently only has an effect ARM platforms where more than one + curve is enabled. */ +#ifndef uECC_OPTIMIZATION_LEVEL + #define uECC_OPTIMIZATION_LEVEL 2 +#endif + +/* uECC_SQUARE_FUNC - If enabled (defined as nonzero), this will cause a specific function to be +used for (scalar) squaring instead of the generic multiplication function. This can make things +faster somewhat faster, but increases the code size. */ +#ifndef uECC_SQUARE_FUNC + #define uECC_SQUARE_FUNC 0 +#endif + +/* uECC_VLI_NATIVE_LITTLE_ENDIAN - If enabled (defined as nonzero), this will switch to native +little-endian format for *all* arrays passed in and out of the public API. This includes public +and private keys, shared secrets, signatures and message hashes. +Using this switch reduces the amount of call stack memory used by uECC, since less intermediate +translations are required. +Note that this will *only* work on native little-endian processors and it will treat the uint8_t +arrays passed into the public API as word arrays, therefore requiring the provided byte arrays +to be word aligned on architectures that do not support unaligned accesses. +IMPORTANT: Keys and signatures generated with uECC_VLI_NATIVE_LITTLE_ENDIAN=1 are incompatible +with keys and signatures generated with uECC_VLI_NATIVE_LITTLE_ENDIAN=0; all parties must use +the same endianness. */ +#ifndef uECC_VLI_NATIVE_LITTLE_ENDIAN + #define uECC_VLI_NATIVE_LITTLE_ENDIAN 0 +#endif + +/* Curve support selection. Set to 0 to remove that curve. */ +#ifndef uECC_SUPPORTS_secp160r1 + #define uECC_SUPPORTS_secp160r1 1 +#endif +#ifndef uECC_SUPPORTS_secp192r1 + #define uECC_SUPPORTS_secp192r1 1 +#endif +#ifndef uECC_SUPPORTS_secp224r1 + #define uECC_SUPPORTS_secp224r1 1 +#endif +#ifndef uECC_SUPPORTS_secp256r1 + #define uECC_SUPPORTS_secp256r1 1 +#endif +#ifndef uECC_SUPPORTS_secp256k1 + #define uECC_SUPPORTS_secp256k1 1 +#endif + +/* Specifies whether compressed point format is supported. + Set to 0 to disable point compression/decompression functions. */ +#ifndef uECC_SUPPORT_COMPRESSED_POINT + #define uECC_SUPPORT_COMPRESSED_POINT 1 +#endif + +struct uECC_Curve_t; +typedef const struct uECC_Curve_t * uECC_Curve; + +#ifdef __cplusplus +extern "C" +{ +#endif + +#if uECC_SUPPORTS_secp160r1 +uECC_Curve uECC_secp160r1(void); +#endif +#if uECC_SUPPORTS_secp192r1 +uECC_Curve uECC_secp192r1(void); +#endif +#if uECC_SUPPORTS_secp224r1 +uECC_Curve uECC_secp224r1(void); +#endif +#if uECC_SUPPORTS_secp256r1 +uECC_Curve uECC_secp256r1(void); +#endif +#if uECC_SUPPORTS_secp256k1 +uECC_Curve uECC_secp256k1(void); +#endif + +/* uECC_RNG_Function type +The RNG function should fill 'size' random bytes into 'dest'. It should return 1 if +'dest' was filled with random data, or 0 if the random data could not be generated. +The filled-in values should be either truly random, or from a cryptographically-secure PRNG. + +A correctly functioning RNG function must be set (using uECC_set_rng()) before calling +uECC_make_key() or uECC_sign(). + +Setting a correctly functioning RNG function improves the resistance to side-channel attacks +for uECC_shared_secret() and uECC_sign_deterministic(). + +A correct RNG function is set by default when building for Windows, Linux, or OS X. +If you are building on another POSIX-compliant system that supports /dev/random or /dev/urandom, +you can define uECC_POSIX to use the predefined RNG. For embedded platforms there is no predefined +RNG function; you must provide your own. +*/ +typedef int (*uECC_RNG_Function)(uint8_t *dest, unsigned size); + +/* uECC_set_rng() function. +Set the function that will be used to generate random bytes. The RNG function should +return 1 if the random data was generated, or 0 if the random data could not be generated. + +On platforms where there is no predefined RNG function (eg embedded platforms), this must +be called before uECC_make_key() or uECC_sign() are used. + +Inputs: + rng_function - The function that will be used to generate random bytes. +*/ +void uECC_set_rng(uECC_RNG_Function rng_function); + +/* uECC_get_rng() function. + +Returns the function that will be used to generate random bytes. +*/ +uECC_RNG_Function uECC_get_rng(void); + +/* uECC_curve_private_key_size() function. + +Returns the size of a private key for the curve in bytes. +*/ +int uECC_curve_private_key_size(uECC_Curve curve); + +/* uECC_curve_public_key_size() function. + +Returns the size of a public key for the curve in bytes. +*/ +int uECC_curve_public_key_size(uECC_Curve curve); + +/* uECC_make_key() function. +Create a public/private key pair. + +Outputs: + public_key - Will be filled in with the public key. Must be at least 2 * the curve size + (in bytes) long. For example, if the curve is secp256r1, public_key must be 64 + bytes long. + private_key - Will be filled in with the private key. Must be as long as the curve order; this + is typically the same as the curve size, except for secp160r1. For example, if the + curve is secp256r1, private_key must be 32 bytes long. + + For secp160r1, private_key must be 21 bytes long! Note that the first byte will + almost always be 0 (there is about a 1 in 2^80 chance of it being non-zero). + +Returns 1 if the key pair was generated successfully, 0 if an error occurred. +*/ +int uECC_make_key(uint8_t *public_key, uint8_t *private_key, uECC_Curve curve); + +/* uECC_shared_secret() function. +Compute a shared secret given your secret key and someone else's public key. +Note: It is recommended that you hash the result of uECC_shared_secret() before using it for +symmetric encryption or HMAC. + +Inputs: + public_key - The public key of the remote party. + private_key - Your private key. + +Outputs: + secret - Will be filled in with the shared secret value. Must be the same size as the + curve size; for example, if the curve is secp256r1, secret must be 32 bytes long. + +Returns 1 if the shared secret was generated successfully, 0 if an error occurred. +*/ +int uECC_shared_secret(const uint8_t *public_key, + const uint8_t *private_key, + uint8_t *secret, + uECC_Curve curve); + +#if uECC_SUPPORT_COMPRESSED_POINT +/* uECC_compress() function. +Compress a public key. + +Inputs: + public_key - The public key to compress. + +Outputs: + compressed - Will be filled in with the compressed public key. Must be at least + (curve size + 1) bytes long; for example, if the curve is secp256r1, + compressed must be 33 bytes long. +*/ +void uECC_compress(const uint8_t *public_key, uint8_t *compressed, uECC_Curve curve); + +/* uECC_decompress() function. +Decompress a compressed public key. + +Inputs: + compressed - The compressed public key. + +Outputs: + public_key - Will be filled in with the decompressed public key. +*/ +void uECC_decompress(const uint8_t *compressed, uint8_t *public_key, uECC_Curve curve); +#endif /* uECC_SUPPORT_COMPRESSED_POINT */ + +/* uECC_valid_public_key() function. +Check to see if a public key is valid. + +Note that you are not required to check for a valid public key before using any other uECC +functions. However, you may wish to avoid spending CPU time computing a shared secret or +verifying a signature using an invalid public key. + +Inputs: + public_key - The public key to check. + +Returns 1 if the public key is valid, 0 if it is invalid. +*/ +int uECC_valid_public_key(const uint8_t *public_key, uECC_Curve curve); + +/* uECC_compute_public_key() function. +Compute the corresponding public key for a private key. + +Inputs: + private_key - The private key to compute the public key for + +Outputs: + public_key - Will be filled in with the corresponding public key + +Returns 1 if the key was computed successfully, 0 if an error occurred. +*/ +int uECC_compute_public_key(const uint8_t *private_key, uint8_t *public_key, uECC_Curve curve); + +/* uECC_sign() function. +Generate an ECDSA signature for a given hash value. + +Usage: Compute a hash of the data you wish to sign (SHA-2 is recommended) and pass it in to +this function along with your private key. + +Inputs: + private_key - Your private key. + message_hash - The hash of the message to sign. + hash_size - The size of message_hash in bytes. + +Outputs: + signature - Will be filled in with the signature value. Must be at least 2 * curve size long. + For example, if the curve is secp256r1, signature must be 64 bytes long. + +Returns 1 if the signature generated successfully, 0 if an error occurred. +*/ +int uECC_sign(const uint8_t *private_key, + const uint8_t *message_hash, + unsigned hash_size, + uint8_t *signature, + uECC_Curve curve); + +/* uECC_HashContext structure. +This is used to pass in an arbitrary hash function to uECC_sign_deterministic(). +The structure will be used for multiple hash computations; each time a new hash +is computed, init_hash() will be called, followed by one or more calls to +update_hash(), and finally a call to finish_hash() to produce the resulting hash. + +The intention is that you will create a structure that includes uECC_HashContext +followed by any hash-specific data. For example: + +typedef struct SHA256_HashContext { + uECC_HashContext uECC; + SHA256_CTX ctx; +} SHA256_HashContext; + +void init_SHA256(uECC_HashContext *base) { + SHA256_HashContext *context = (SHA256_HashContext *)base; + SHA256_Init(&context->ctx); +} + +void update_SHA256(uECC_HashContext *base, + const uint8_t *message, + unsigned message_size) { + SHA256_HashContext *context = (SHA256_HashContext *)base; + SHA256_Update(&context->ctx, message, message_size); +} + +void finish_SHA256(uECC_HashContext *base, uint8_t *hash_result) { + SHA256_HashContext *context = (SHA256_HashContext *)base; + SHA256_Final(hash_result, &context->ctx); +} + +... when signing ... +{ + uint8_t tmp[32 + 32 + 64]; + SHA256_HashContext ctx = {{&init_SHA256, &update_SHA256, &finish_SHA256, 64, 32, tmp}}; + uECC_sign_deterministic(key, message_hash, &ctx.uECC, signature); +} +*/ +typedef struct uECC_HashContext { + void (*init_hash)(const struct uECC_HashContext *context); + void (*update_hash)(const struct uECC_HashContext *context, + const uint8_t *message, + unsigned message_size); + void (*finish_hash)(const struct uECC_HashContext *context, uint8_t *hash_result); + unsigned block_size; /* Hash function block size in bytes, eg 64 for SHA-256. */ + unsigned result_size; /* Hash function result size in bytes, eg 32 for SHA-256. */ + uint8_t *tmp; /* Must point to a buffer of at least (2 * result_size + block_size) bytes. */ +} uECC_HashContext; + +/* uECC_sign_deterministic() function. +Generate an ECDSA signature for a given hash value, using a deterministic algorithm +(see RFC 6979). You do not need to set the RNG using uECC_set_rng() before calling +this function; however, if the RNG is defined it will improve resistance to side-channel +attacks. + +Usage: Compute a hash of the data you wish to sign (SHA-2 is recommended) and pass it to +this function along with your private key and a hash context. Note that the message_hash +does not need to be computed with the same hash function used by hash_context. + +Inputs: + private_key - Your private key. + message_hash - The hash of the message to sign. + hash_size - The size of message_hash in bytes. + hash_context - A hash context to use. + +Outputs: + signature - Will be filled in with the signature value. + +Returns 1 if the signature generated successfully, 0 if an error occurred. +*/ +int uECC_sign_deterministic(const uint8_t *private_key, + const uint8_t *message_hash, + unsigned hash_size, + const uECC_HashContext *hash_context, + uint8_t *signature, + uECC_Curve curve); + +/* uECC_verify() function. +Verify an ECDSA signature. + +Usage: Compute the hash of the signed data using the same hash as the signer and +pass it to this function along with the signer's public key and the signature values (r and s). + +Inputs: + public_key - The signer's public key. + message_hash - The hash of the signed data. + hash_size - The size of message_hash in bytes. + signature - The signature value. + +Returns 1 if the signature is valid, 0 if it is invalid. +*/ +int uECC_verify(const uint8_t *public_key, + const uint8_t *message_hash, + unsigned hash_size, + const uint8_t *signature, + uECC_Curve curve); + +#ifdef __cplusplus +} /* end of extern "C" */ +#endif + +#endif /* _UECC_H_ */
diff -r 000000000000 -r b6fdeddc0bc9 uECC_vli.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/uECC_vli.h Thu Sep 07 12:10:11 2017 +0000 @@ -0,0 +1,172 @@ +/* Copyright 2015, Kenneth MacKay. Licensed under the BSD 2-clause license. */ + +#ifndef _UECC_VLI_H_ +#define _UECC_VLI_H_ + +#include "uECC.h" +#include "types.h" + +/* Functions for raw large-integer manipulation. These are only available + if uECC.c is compiled with uECC_ENABLE_VLI_API defined to 1. */ +#ifndef uECC_ENABLE_VLI_API + #define uECC_ENABLE_VLI_API 0 +#endif + +#ifdef __cplusplus +extern "C" +{ +#endif + +#if uECC_ENABLE_VLI_API + +void uECC_vli_clear(uECC_word_t *vli, wordcount_t num_words); + +/* Constant-time comparison to zero - secure way to compare long integers */ +/* Returns 1 if vli == 0, 0 otherwise. */ +uECC_word_t uECC_vli_isZero(const uECC_word_t *vli, wordcount_t num_words); + +/* Returns nonzero if bit 'bit' of vli is set. */ +uECC_word_t uECC_vli_testBit(const uECC_word_t *vli, bitcount_t bit); + +/* Counts the number of bits required to represent vli. */ +bitcount_t uECC_vli_numBits(const uECC_word_t *vli, const wordcount_t max_words); + +/* Sets dest = src. */ +void uECC_vli_set(uECC_word_t *dest, const uECC_word_t *src, wordcount_t num_words); + +/* Constant-time comparison function - secure way to compare long integers */ +/* Returns one if left == right, zero otherwise */ +uECC_word_t uECC_vli_equal(const uECC_word_t *left, + const uECC_word_t *right, + wordcount_t num_words); + +/* Constant-time comparison function - secure way to compare long integers */ +/* Returns sign of left - right, in constant time. */ +cmpresult_t uECC_vli_cmp(const uECC_word_t *left, const uECC_word_t *right, wordcount_t num_words); + +/* Computes vli = vli >> 1. */ +void uECC_vli_rshift1(uECC_word_t *vli, wordcount_t num_words); + +/* Computes result = left + right, returning carry. Can modify in place. */ +uECC_word_t uECC_vli_add(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + wordcount_t num_words); + +/* Computes result = left - right, returning borrow. Can modify in place. */ +uECC_word_t uECC_vli_sub(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + wordcount_t num_words); + +/* Computes result = left * right. Result must be 2 * num_words long. */ +void uECC_vli_mult(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + wordcount_t num_words); + +/* Computes result = left^2. Result must be 2 * num_words long. */ +void uECC_vli_square(uECC_word_t *result, const uECC_word_t *left, wordcount_t num_words); + +/* Computes result = (left + right) % mod. + Assumes that left < mod and right < mod, and that result does not overlap mod. */ +void uECC_vli_modAdd(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + const uECC_word_t *mod, + wordcount_t num_words); + +/* Computes result = (left - right) % mod. + Assumes that left < mod and right < mod, and that result does not overlap mod. */ +void uECC_vli_modSub(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + const uECC_word_t *mod, + wordcount_t num_words); + +/* Computes result = product % mod, where product is 2N words long. + Currently only designed to work for mod == curve->p or curve_n. */ +void uECC_vli_mmod(uECC_word_t *result, + uECC_word_t *product, + const uECC_word_t *mod, + wordcount_t num_words); + +/* Calculates result = product (mod curve->p), where product is up to + 2 * curve->num_words long. */ +void uECC_vli_mmod_fast(uECC_word_t *result, uECC_word_t *product, uECC_Curve curve); + +/* Computes result = (left * right) % mod. + Currently only designed to work for mod == curve->p or curve_n. */ +void uECC_vli_modMult(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + const uECC_word_t *mod, + wordcount_t num_words); + +/* Computes result = (left * right) % curve->p. */ +void uECC_vli_modMult_fast(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *right, + uECC_Curve curve); + +/* Computes result = left^2 % mod. + Currently only designed to work for mod == curve->p or curve_n. */ +void uECC_vli_modSquare(uECC_word_t *result, + const uECC_word_t *left, + const uECC_word_t *mod, + wordcount_t num_words); + +/* Computes result = left^2 % curve->p. */ +void uECC_vli_modSquare_fast(uECC_word_t *result, const uECC_word_t *left, uECC_Curve curve); + +/* Computes result = (1 / input) % mod.*/ +void uECC_vli_modInv(uECC_word_t *result, + const uECC_word_t *input, + const uECC_word_t *mod, + wordcount_t num_words); + +#if uECC_SUPPORT_COMPRESSED_POINT +/* Calculates a = sqrt(a) (mod curve->p) */ +void uECC_vli_mod_sqrt(uECC_word_t *a, uECC_Curve curve); +#endif + +/* Converts an integer in uECC native format to big-endian bytes. */ +void uECC_vli_nativeToBytes(uint8_t *bytes, int num_bytes, const uECC_word_t *native); +/* Converts big-endian bytes to an integer in uECC native format. */ +void uECC_vli_bytesToNative(uECC_word_t *native, const uint8_t *bytes, int num_bytes); + +unsigned uECC_curve_num_words(uECC_Curve curve); +unsigned uECC_curve_num_bytes(uECC_Curve curve); +unsigned uECC_curve_num_bits(uECC_Curve curve); +unsigned uECC_curve_num_n_words(uECC_Curve curve); +unsigned uECC_curve_num_n_bytes(uECC_Curve curve); +unsigned uECC_curve_num_n_bits(uECC_Curve curve); + +const uECC_word_t *uECC_curve_p(uECC_Curve curve); +const uECC_word_t *uECC_curve_n(uECC_Curve curve); +const uECC_word_t *uECC_curve_G(uECC_Curve curve); +const uECC_word_t *uECC_curve_b(uECC_Curve curve); + +int uECC_valid_point(const uECC_word_t *point, uECC_Curve curve); + +/* Multiplies a point by a scalar. Points are represented by the X coordinate followed by + the Y coordinate in the same array, both coordinates are curve->num_words long. Note + that scalar must be curve->num_n_words long (NOT curve->num_words). */ +void uECC_point_mult(uECC_word_t *result, + const uECC_word_t *point, + const uECC_word_t *scalar, + uECC_Curve curve); + +/* Generates a random integer in the range 0 < random < top. + Both random and top have num_words words. */ +int uECC_generate_random_int(uECC_word_t *random, + const uECC_word_t *top, + wordcount_t num_words); + +#endif /* uECC_ENABLE_VLI_API */ + +#ifdef __cplusplus +} /* end of extern "C" */ +#endif + +#endif /* _UECC_VLI_H_ */