Hannes Tschofenig
Example program to test AES-GCM functionality. Used for a workshop
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aesni.c
00001 /* 00002 * AES-NI support functions 00003 * 00004 * Copyright (C) 2013, Brainspark B.V. 00005 * 00006 * This file is part of PolarSSL (http://www.polarssl.org) 00007 * Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org> 00008 * 00009 * All rights reserved. 00010 * 00011 * This program is free software; you can redistribute it and/or modify 00012 * it under the terms of the GNU General Public License as published by 00013 * the Free Software Foundation; either version 2 of the License, or 00014 * (at your option) any later version. 00015 * 00016 * This program is distributed in the hope that it will be useful, 00017 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00018 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00019 * GNU General Public License for more details. 00020 * 00021 * You should have received a copy of the GNU General Public License along 00022 * with this program; if not, write to the Free Software Foundation, Inc., 00023 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 00024 */ 00025 00026 /* 00027 * [AES-WP] http://software.intel.com/en-us/articles/intel-advanced-encryption-standard-aes-instructions-set 00028 * [CLMUL-WP] http://software.intel.com/en-us/articles/intel-carry-less-multiplication-instruction-and-its-usage-for-computing-the-gcm-mode/ 00029 */ 00030 00031 #if !defined(POLARSSL_CONFIG_FILE) 00032 #include "polarssl/config.h" 00033 #else 00034 #include POLARSSL_CONFIG_FILE 00035 #endif 00036 00037 #if defined(POLARSSL_AESNI_C) 00038 00039 #include "polarssl/aesni.h" 00040 #include <stdio.h> 00041 00042 #if defined(POLARSSL_HAVE_X86_64) 00043 00044 /* 00045 * AES-NI support detection routine 00046 */ 00047 int aesni_supports( unsigned int what ) 00048 { 00049 static int done = 0; 00050 static unsigned int c = 0; 00051 00052 if( ! done ) 00053 { 00054 asm( "movl $1, %%eax \n" 00055 "cpuid \n" 00056 : "=c" (c) 00057 : 00058 : "eax", "ebx", "edx" ); 00059 done = 1; 00060 } 00061 00062 return( ( c & what ) != 0 ); 00063 } 00064 00065 /* 00066 * Binutils needs to be at least 2.19 to support AES-NI instructions. 00067 * Unfortunately, a lot of users have a lower version now (2014-04). 00068 * Emit bytecode directly in order to support "old" version of gas. 00069 * 00070 * Opcodes from the Intel architecture reference manual, vol. 3. 00071 * We always use registers, so we don't need prefixes for memory operands. 00072 * Operand macros are in gas order (src, dst) as opposed to Intel order 00073 * (dst, src) in order to blend better into the surrounding assembly code. 00074 */ 00075 #define AESDEC ".byte 0x66,0x0F,0x38,0xDE," 00076 #define AESDECLAST ".byte 0x66,0x0F,0x38,0xDF," 00077 #define AESENC ".byte 0x66,0x0F,0x38,0xDC," 00078 #define AESENCLAST ".byte 0x66,0x0F,0x38,0xDD," 00079 #define AESIMC ".byte 0x66,0x0F,0x38,0xDB," 00080 #define AESKEYGENA ".byte 0x66,0x0F,0x3A,0xDF," 00081 #define PCLMULQDQ ".byte 0x66,0x0F,0x3A,0x44," 00082 00083 #define xmm0_xmm0 "0xC0" 00084 #define xmm0_xmm1 "0xC8" 00085 #define xmm0_xmm2 "0xD0" 00086 #define xmm0_xmm3 "0xD8" 00087 #define xmm0_xmm4 "0xE0" 00088 #define xmm1_xmm0 "0xC1" 00089 #define xmm1_xmm2 "0xD1" 00090 00091 /* 00092 * AES-NI AES-ECB block en(de)cryption 00093 */ 00094 int aesni_crypt_ecb( aes_context *ctx, 00095 int mode, 00096 const unsigned char input[16], 00097 unsigned char output[16] ) 00098 { 00099 asm( "movdqu (%3), %%xmm0 \n" // load input 00100 "movdqu (%1), %%xmm1 \n" // load round key 0 00101 "pxor %%xmm1, %%xmm0 \n" // round 0 00102 "addq $16, %1 \n" // point to next round key 00103 "subl $1, %0 \n" // normal rounds = nr - 1 00104 "test %2, %2 \n" // mode? 00105 "jz 2f \n" // 0 = decrypt 00106 00107 "1: \n" // encryption loop 00108 "movdqu (%1), %%xmm1 \n" // load round key 00109 AESENC xmm1_xmm0 "\n" // do round 00110 "addq $16, %1 \n" // point to next round key 00111 "subl $1, %0 \n" // loop 00112 "jnz 1b \n" 00113 "movdqu (%1), %%xmm1 \n" // load round key 00114 AESENCLAST xmm1_xmm0 "\n" // last round 00115 "jmp 3f \n" 00116 00117 "2: \n" // decryption loop 00118 "movdqu (%1), %%xmm1 \n" 00119 AESDEC xmm1_xmm0 "\n" // do round 00120 "addq $16, %1 \n" 00121 "subl $1, %0 \n" 00122 "jnz 2b \n" 00123 "movdqu (%1), %%xmm1 \n" // load round key 00124 AESDECLAST xmm1_xmm0 "\n" // last round 00125 00126 "3: \n" 00127 "movdqu %%xmm0, (%4) \n" // export output 00128 : 00129 : "r" (ctx->nr ), "r" (ctx->rk ), "r" (mode), "r" (input), "r" (output) 00130 : "memory", "cc", "xmm0", "xmm1" ); 00131 00132 00133 return( 0 ); 00134 } 00135 00136 /* 00137 * GCM multiplication: c = a times b in GF(2^128) 00138 * Based on [CLMUL-WP] algorithms 1 (with equation 27) and 5. 00139 */ 00140 void aesni_gcm_mult( unsigned char c[16], 00141 const unsigned char a[16], 00142 const unsigned char b[16] ) 00143 { 00144 unsigned char aa[16], bb[16], cc[16]; 00145 size_t i; 00146 00147 /* The inputs are in big-endian order, so byte-reverse them */ 00148 for( i = 0; i < 16; i++ ) 00149 { 00150 aa[i] = a[15 - i]; 00151 bb[i] = b[15 - i]; 00152 } 00153 00154 asm( "movdqu (%0), %%xmm0 \n" // a1:a0 00155 "movdqu (%1), %%xmm1 \n" // b1:b0 00156 00157 /* 00158 * Caryless multiplication xmm2:xmm1 = xmm0 * xmm1 00159 * using [CLMUL-WP] algorithm 1 (p. 13). 00160 */ 00161 "movdqa %%xmm1, %%xmm2 \n" // copy of b1:b0 00162 "movdqa %%xmm1, %%xmm3 \n" // same 00163 "movdqa %%xmm1, %%xmm4 \n" // same 00164 PCLMULQDQ xmm0_xmm1 ",0x00 \n" // a0*b0 = c1:c0 00165 PCLMULQDQ xmm0_xmm2 ",0x11 \n" // a1*b1 = d1:d0 00166 PCLMULQDQ xmm0_xmm3 ",0x10 \n" // a0*b1 = e1:e0 00167 PCLMULQDQ xmm0_xmm4 ",0x01 \n" // a1*b0 = f1:f0 00168 "pxor %%xmm3, %%xmm4 \n" // e1+f1:e0+f0 00169 "movdqa %%xmm4, %%xmm3 \n" // same 00170 "psrldq $8, %%xmm4 \n" // 0:e1+f1 00171 "pslldq $8, %%xmm3 \n" // e0+f0:0 00172 "pxor %%xmm4, %%xmm2 \n" // d1:d0+e1+f1 00173 "pxor %%xmm3, %%xmm1 \n" // c1+e0+f1:c0 00174 00175 /* 00176 * Now shift the result one bit to the left, 00177 * taking advantage of [CLMUL-WP] eq 27 (p. 20) 00178 */ 00179 "movdqa %%xmm1, %%xmm3 \n" // r1:r0 00180 "movdqa %%xmm2, %%xmm4 \n" // r3:r2 00181 "psllq $1, %%xmm1 \n" // r1<<1:r0<<1 00182 "psllq $1, %%xmm2 \n" // r3<<1:r2<<1 00183 "psrlq $63, %%xmm3 \n" // r1>>63:r0>>63 00184 "psrlq $63, %%xmm4 \n" // r3>>63:r2>>63 00185 "movdqa %%xmm3, %%xmm5 \n" // r1>>63:r0>>63 00186 "pslldq $8, %%xmm3 \n" // r0>>63:0 00187 "pslldq $8, %%xmm4 \n" // r2>>63:0 00188 "psrldq $8, %%xmm5 \n" // 0:r1>>63 00189 "por %%xmm3, %%xmm1 \n" // r1<<1|r0>>63:r0<<1 00190 "por %%xmm4, %%xmm2 \n" // r3<<1|r2>>62:r2<<1 00191 "por %%xmm5, %%xmm2 \n" // r3<<1|r2>>62:r2<<1|r1>>63 00192 00193 /* 00194 * Now reduce modulo the GCM polynomial x^128 + x^7 + x^2 + x + 1 00195 * using [CLMUL-WP] algorithm 5 (p. 20). 00196 * Currently xmm2:xmm1 holds x3:x2:x1:x0 (already shifted). 00197 */ 00198 /* Step 2 (1) */ 00199 "movdqa %%xmm1, %%xmm3 \n" // x1:x0 00200 "movdqa %%xmm1, %%xmm4 \n" // same 00201 "movdqa %%xmm1, %%xmm5 \n" // same 00202 "psllq $63, %%xmm3 \n" // x1<<63:x0<<63 = stuff:a 00203 "psllq $62, %%xmm4 \n" // x1<<62:x0<<62 = stuff:b 00204 "psllq $57, %%xmm5 \n" // x1<<57:x0<<57 = stuff:c 00205 00206 /* Step 2 (2) */ 00207 "pxor %%xmm4, %%xmm3 \n" // stuff:a+b 00208 "pxor %%xmm5, %%xmm3 \n" // stuff:a+b+c 00209 "pslldq $8, %%xmm3 \n" // a+b+c:0 00210 "pxor %%xmm3, %%xmm1 \n" // x1+a+b+c:x0 = d:x0 00211 00212 /* Steps 3 and 4 */ 00213 "movdqa %%xmm1,%%xmm0 \n" // d:x0 00214 "movdqa %%xmm1,%%xmm4 \n" // same 00215 "movdqa %%xmm1,%%xmm5 \n" // same 00216 "psrlq $1, %%xmm0 \n" // e1:x0>>1 = e1:e0' 00217 "psrlq $2, %%xmm4 \n" // f1:x0>>2 = f1:f0' 00218 "psrlq $7, %%xmm5 \n" // g1:x0>>7 = g1:g0' 00219 "pxor %%xmm4, %%xmm0 \n" // e1+f1:e0'+f0' 00220 "pxor %%xmm5, %%xmm0 \n" // e1+f1+g1:e0'+f0'+g0' 00221 // e0'+f0'+g0' is almost e0+f0+g0, except for some missing 00222 // bits carried from d. Now get those bits back in. 00223 "movdqa %%xmm1,%%xmm3 \n" // d:x0 00224 "movdqa %%xmm1,%%xmm4 \n" // same 00225 "movdqa %%xmm1,%%xmm5 \n" // same 00226 "psllq $63, %%xmm3 \n" // d<<63:stuff 00227 "psllq $62, %%xmm4 \n" // d<<62:stuff 00228 "psllq $57, %%xmm5 \n" // d<<57:stuff 00229 "pxor %%xmm4, %%xmm3 \n" // d<<63+d<<62:stuff 00230 "pxor %%xmm5, %%xmm3 \n" // missing bits of d:stuff 00231 "psrldq $8, %%xmm3 \n" // 0:missing bits of d 00232 "pxor %%xmm3, %%xmm0 \n" // e1+f1+g1:e0+f0+g0 00233 "pxor %%xmm1, %%xmm0 \n" // h1:h0 00234 "pxor %%xmm2, %%xmm0 \n" // x3+h1:x2+h0 00235 00236 "movdqu %%xmm0, (%2) \n" // done 00237 : 00238 : "r" (aa), "r" (bb), "r" (cc) 00239 : "memory", "cc", "xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5" ); 00240 00241 /* Now byte-reverse the outputs */ 00242 for( i = 0; i < 16; i++ ) 00243 c[i] = cc[15 - i]; 00244 00245 return; 00246 } 00247 00248 /* 00249 * Compute decryption round keys from encryption round keys 00250 */ 00251 void aesni_inverse_key( unsigned char *invkey, 00252 const unsigned char *fwdkey, int nr ) 00253 { 00254 unsigned char *ik = invkey; 00255 const unsigned char *fk = fwdkey + 16 * nr; 00256 00257 memcpy( ik, fk, 16 ); 00258 00259 for( fk -= 16, ik += 16; fk > fwdkey; fk -= 16, ik += 16 ) 00260 asm( "movdqu (%0), %%xmm0 \n" 00261 AESIMC xmm0_xmm0 "\n" 00262 "movdqu %%xmm0, (%1) \n" 00263 : 00264 : "r" (fk), "r" (ik) 00265 : "memory", "xmm0" ); 00266 00267 memcpy( ik, fk, 16 ); 00268 } 00269 00270 /* 00271 * Key expansion, 128-bit case 00272 */ 00273 static void aesni_setkey_enc_128( unsigned char *rk, 00274 const unsigned char *key ) 00275 { 00276 asm( "movdqu (%1), %%xmm0 \n" // copy the original key 00277 "movdqu %%xmm0, (%0) \n" // as round key 0 00278 "jmp 2f \n" // skip auxiliary routine 00279 00280 /* 00281 * Finish generating the next round key. 00282 * 00283 * On entry xmm0 is r3:r2:r1:r0 and xmm1 is X:stuff:stuff:stuff 00284 * with X = rot( sub( r3 ) ) ^ RCON. 00285 * 00286 * On exit, xmm0 is r7:r6:r5:r4 00287 * with r4 = X + r0, r5 = r4 + r1, r6 = r5 + r2, r7 = r6 + r3 00288 * and those are written to the round key buffer. 00289 */ 00290 "1: \n" 00291 "pshufd $0xff, %%xmm1, %%xmm1 \n" // X:X:X:X 00292 "pxor %%xmm0, %%xmm1 \n" // X+r3:X+r2:X+r1:r4 00293 "pslldq $4, %%xmm0 \n" // r2:r1:r0:0 00294 "pxor %%xmm0, %%xmm1 \n" // X+r3+r2:X+r2+r1:r5:r4 00295 "pslldq $4, %%xmm0 \n" // etc 00296 "pxor %%xmm0, %%xmm1 \n" 00297 "pslldq $4, %%xmm0 \n" 00298 "pxor %%xmm1, %%xmm0 \n" // update xmm0 for next time! 00299 "add $16, %0 \n" // point to next round key 00300 "movdqu %%xmm0, (%0) \n" // write it 00301 "ret \n" 00302 00303 /* Main "loop" */ 00304 "2: \n" 00305 AESKEYGENA xmm0_xmm1 ",0x01 \ncall 1b \n" 00306 AESKEYGENA xmm0_xmm1 ",0x02 \ncall 1b \n" 00307 AESKEYGENA xmm0_xmm1 ",0x04 \ncall 1b \n" 00308 AESKEYGENA xmm0_xmm1 ",0x08 \ncall 1b \n" 00309 AESKEYGENA xmm0_xmm1 ",0x10 \ncall 1b \n" 00310 AESKEYGENA xmm0_xmm1 ",0x20 \ncall 1b \n" 00311 AESKEYGENA xmm0_xmm1 ",0x40 \ncall 1b \n" 00312 AESKEYGENA xmm0_xmm1 ",0x80 \ncall 1b \n" 00313 AESKEYGENA xmm0_xmm1 ",0x1B \ncall 1b \n" 00314 AESKEYGENA xmm0_xmm1 ",0x36 \ncall 1b \n" 00315 : 00316 : "r" (rk), "r" (key) 00317 : "memory", "cc", "0" ); 00318 } 00319 00320 /* 00321 * Key expansion, 192-bit case 00322 */ 00323 static void aesni_setkey_enc_192( unsigned char *rk, 00324 const unsigned char *key ) 00325 { 00326 asm( "movdqu (%1), %%xmm0 \n" // copy original round key 00327 "movdqu %%xmm0, (%0) \n" 00328 "add $16, %0 \n" 00329 "movq 16(%1), %%xmm1 \n" 00330 "movq %%xmm1, (%0) \n" 00331 "add $8, %0 \n" 00332 "jmp 2f \n" // skip auxiliary routine 00333 00334 /* 00335 * Finish generating the next 6 quarter-keys. 00336 * 00337 * On entry xmm0 is r3:r2:r1:r0, xmm1 is stuff:stuff:r5:r4 00338 * and xmm2 is stuff:stuff:X:stuff with X = rot( sub( r3 ) ) ^ RCON. 00339 * 00340 * On exit, xmm0 is r9:r8:r7:r6 and xmm1 is stuff:stuff:r11:r10 00341 * and those are written to the round key buffer. 00342 */ 00343 "1: \n" 00344 "pshufd $0x55, %%xmm2, %%xmm2 \n" // X:X:X:X 00345 "pxor %%xmm0, %%xmm2 \n" // X+r3:X+r2:X+r1:r4 00346 "pslldq $4, %%xmm0 \n" // etc 00347 "pxor %%xmm0, %%xmm2 \n" 00348 "pslldq $4, %%xmm0 \n" 00349 "pxor %%xmm0, %%xmm2 \n" 00350 "pslldq $4, %%xmm0 \n" 00351 "pxor %%xmm2, %%xmm0 \n" // update xmm0 = r9:r8:r7:r6 00352 "movdqu %%xmm0, (%0) \n" 00353 "add $16, %0 \n" 00354 "pshufd $0xff, %%xmm0, %%xmm2 \n" // r9:r9:r9:r9 00355 "pxor %%xmm1, %%xmm2 \n" // stuff:stuff:r9+r5:r10 00356 "pslldq $4, %%xmm1 \n" // r2:r1:r0:0 00357 "pxor %%xmm2, %%xmm1 \n" // update xmm1 = stuff:stuff:r11:r10 00358 "movq %%xmm1, (%0) \n" 00359 "add $8, %0 \n" 00360 "ret \n" 00361 00362 "2: \n" 00363 AESKEYGENA xmm1_xmm2 ",0x01 \ncall 1b \n" 00364 AESKEYGENA xmm1_xmm2 ",0x02 \ncall 1b \n" 00365 AESKEYGENA xmm1_xmm2 ",0x04 \ncall 1b \n" 00366 AESKEYGENA xmm1_xmm2 ",0x08 \ncall 1b \n" 00367 AESKEYGENA xmm1_xmm2 ",0x10 \ncall 1b \n" 00368 AESKEYGENA xmm1_xmm2 ",0x20 \ncall 1b \n" 00369 AESKEYGENA xmm1_xmm2 ",0x40 \ncall 1b \n" 00370 AESKEYGENA xmm1_xmm2 ",0x80 \ncall 1b \n" 00371 00372 : 00373 : "r" (rk), "r" (key) 00374 : "memory", "cc", "0" ); 00375 } 00376 00377 /* 00378 * Key expansion, 256-bit case 00379 */ 00380 static void aesni_setkey_enc_256( unsigned char *rk, 00381 const unsigned char *key ) 00382 { 00383 asm( "movdqu (%1), %%xmm0 \n" 00384 "movdqu %%xmm0, (%0) \n" 00385 "add $16, %0 \n" 00386 "movdqu 16(%1), %%xmm1 \n" 00387 "movdqu %%xmm1, (%0) \n" 00388 "jmp 2f \n" // skip auxiliary routine 00389 00390 /* 00391 * Finish generating the next two round keys. 00392 * 00393 * On entry xmm0 is r3:r2:r1:r0, xmm1 is r7:r6:r5:r4 and 00394 * xmm2 is X:stuff:stuff:stuff with X = rot( sub( r7 )) ^ RCON 00395 * 00396 * On exit, xmm0 is r11:r10:r9:r8 and xmm1 is r15:r14:r13:r12 00397 * and those have been written to the output buffer. 00398 */ 00399 "1: \n" 00400 "pshufd $0xff, %%xmm2, %%xmm2 \n" 00401 "pxor %%xmm0, %%xmm2 \n" 00402 "pslldq $4, %%xmm0 \n" 00403 "pxor %%xmm0, %%xmm2 \n" 00404 "pslldq $4, %%xmm0 \n" 00405 "pxor %%xmm0, %%xmm2 \n" 00406 "pslldq $4, %%xmm0 \n" 00407 "pxor %%xmm2, %%xmm0 \n" 00408 "add $16, %0 \n" 00409 "movdqu %%xmm0, (%0) \n" 00410 00411 /* Set xmm2 to stuff:Y:stuff:stuff with Y = subword( r11 ) 00412 * and proceed to generate next round key from there */ 00413 AESKEYGENA xmm0_xmm2 ",0x00 \n" 00414 "pshufd $0xaa, %%xmm2, %%xmm2 \n" 00415 "pxor %%xmm1, %%xmm2 \n" 00416 "pslldq $4, %%xmm1 \n" 00417 "pxor %%xmm1, %%xmm2 \n" 00418 "pslldq $4, %%xmm1 \n" 00419 "pxor %%xmm1, %%xmm2 \n" 00420 "pslldq $4, %%xmm1 \n" 00421 "pxor %%xmm2, %%xmm1 \n" 00422 "add $16, %0 \n" 00423 "movdqu %%xmm1, (%0) \n" 00424 "ret \n" 00425 00426 /* 00427 * Main "loop" - Generating one more key than necessary, 00428 * see definition of aes_context.buf 00429 */ 00430 "2: \n" 00431 AESKEYGENA xmm1_xmm2 ",0x01 \ncall 1b \n" 00432 AESKEYGENA xmm1_xmm2 ",0x02 \ncall 1b \n" 00433 AESKEYGENA xmm1_xmm2 ",0x04 \ncall 1b \n" 00434 AESKEYGENA xmm1_xmm2 ",0x08 \ncall 1b \n" 00435 AESKEYGENA xmm1_xmm2 ",0x10 \ncall 1b \n" 00436 AESKEYGENA xmm1_xmm2 ",0x20 \ncall 1b \n" 00437 AESKEYGENA xmm1_xmm2 ",0x40 \ncall 1b \n" 00438 : 00439 : "r" (rk), "r" (key) 00440 : "memory", "cc", "0" ); 00441 } 00442 00443 /* 00444 * Key expansion, wrapper 00445 */ 00446 int aesni_setkey_enc( unsigned char *rk, 00447 const unsigned char *key, 00448 size_t bits ) 00449 { 00450 switch( bits ) 00451 { 00452 case 128: aesni_setkey_enc_128( rk, key ); break; 00453 case 192: aesni_setkey_enc_192( rk, key ); break; 00454 case 256: aesni_setkey_enc_256( rk, key ); break; 00455 default : return( POLARSSL_ERR_AES_INVALID_KEY_LENGTH ); 00456 } 00457 00458 return( 0 ); 00459 } 00460 00461 #endif /* POLARSSL_HAVE_X86_64 */ 00462 00463 #endif /* POLARSSL_AESNI_C */ 00464 00465
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