misc.c

00001 /* misc.c
00002  *
00003  * Copyright (C) 2006-2017 wolfSSL Inc.
00004  *
00005  * This file is part of wolfSSL.
00006  *
00007  * wolfSSL is free software; you can redistribute it and/or modify
00008  * it under the terms of the GNU General Public License as published by
00009  * the Free Software Foundation; either version 2 of the License, or
00010  * (at your option) any later version.
00011  *
00012  * wolfSSL is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015  * GNU General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU General Public License
00018  * along with this program; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
00020  */
00021 
00022 
00023 #ifdef HAVE_CONFIG_H
00024     #include <config.h>
00025 #endif
00026 
00027 #include <wolfcrypt/settings.h>
00028 
00029 #ifndef WOLF_CRYPT_MISC_C
00030 #define WOLF_CRYPT_MISC_C
00031 
00032 #include <wolfcrypt/misc.h>
00033 
00034 /* inlining these functions is a huge speed increase and a small size decrease,
00035    because the functions are smaller than function call setup/cleanup, e.g.,
00036    md5 benchmark is twice as fast with inline.  If you don't want it, then
00037    define NO_INLINE and compile this file into wolfssl, otherwise it's used as
00038    a source header
00039  */
00040 
00041 #ifdef NO_INLINE
00042     #define STATIC
00043 #else
00044     #define STATIC static
00045 #endif
00046 
00047 /* Check for if compiling misc.c when not needed. */
00048 #if !defined(WOLFSSL_MISC_INCLUDED) && !defined(NO_INLINE)
00049     #ifndef WOLFSSL_IGNORE_FILE_WARN
00050         #warning misc.c does not need to be compiled when using inline (NO_INLINE not defined)
00051     #endif
00052 
00053 #else
00054 
00055 
00056 #if defined(__ICCARM__)
00057     #include <intrinsics.h>
00058 #endif
00059 
00060 
00061 #ifdef INTEL_INTRINSICS
00062 
00063     #include <stdlib.h>      /* get intrinsic definitions */
00064 
00065     /* for non visual studio probably need no long version, 32 bit only
00066      * i.e., _rotl and _rotr */
00067     #pragma intrinsic(_lrotl, _lrotr)
00068 
00069     STATIC WC_INLINE word32 rotlFixed(word32 x, word32 y)
00070     {
00071         return y ? _lrotl(x, y) : x;
00072     }
00073 
00074     STATIC WC_INLINE word32 rotrFixed(word32 x, word32 y)
00075     {
00076         return y ? _lrotr(x, y) : x;
00077     }
00078 
00079 #else /* generic */
00080 
00081     STATIC WC_INLINE word32 rotlFixed(word32 x, word32 y)
00082     {
00083         return (x << y) | (x >> (sizeof(y) * 8 - y));
00084     }
00085 
00086 
00087     STATIC WC_INLINE word32 rotrFixed(word32 x, word32 y)
00088     {
00089         return (x >> y) | (x << (sizeof(y) * 8 - y));
00090     }
00091 
00092 #endif
00093 
00094 
00095 STATIC WC_INLINE word32 ByteReverseWord32(word32 value)
00096 {
00097 #ifdef PPC_INTRINSICS
00098     /* PPC: load reverse indexed instruction */
00099     return (word32)__lwbrx(&value,0);
00100 #elif defined(__ICCARM__)
00101     return (word32)__REV(value);
00102 #elif defined(KEIL_INTRINSICS)
00103     return (word32)__rev(value);
00104 #elif defined(WOLF_ALLOW_BUILTIN) && \
00105         defined(__GNUC_PREREQ) && __GNUC_PREREQ(4, 3)
00106     return (word32)__builtin_bswap32(value);
00107 #elif defined(FAST_ROTATE)
00108     /* 5 instructions with rotate instruction, 9 without */
00109     return (rotrFixed(value, 8U) & 0xff00ff00) |
00110            (rotlFixed(value, 8U) & 0x00ff00ff);
00111 #else
00112     /* 6 instructions with rotate instruction, 8 without */
00113     value = ((value & 0xFF00FF00) >> 8) | ((value & 0x00FF00FF) << 8);
00114     return rotlFixed(value, 16U);
00115 #endif
00116 }
00117 
00118 
00119 STATIC WC_INLINE void ByteReverseWords(word32* out, const word32* in,
00120                                     word32 byteCount)
00121 {
00122     word32 count = byteCount/(word32)sizeof(word32), i;
00123 
00124     for (i = 0; i < count; i++)
00125         out[i] = ByteReverseWord32(in[i]);
00126 
00127 }
00128 
00129 
00130 #ifdef WORD64_AVAILABLE
00131 
00132 
00133 STATIC WC_INLINE word64 rotlFixed64(word64 x, word64 y)
00134 {
00135     return (x << y) | (x >> (sizeof(y) * 8 - y));
00136 }
00137 
00138 
00139 STATIC WC_INLINE word64 rotrFixed64(word64 x, word64 y)
00140 {
00141     return (x >> y) | (x << (sizeof(y) * 8 - y));
00142 }
00143 
00144 
00145 STATIC WC_INLINE word64 ByteReverseWord64(word64 value)
00146 {
00147 #if defined(WOLF_ALLOW_BUILTIN) && defined(__GNUC_PREREQ) && __GNUC_PREREQ(4, 3)
00148     return (word64)__builtin_bswap64(value);
00149 #elif defined(WOLFCRYPT_SLOW_WORD64)
00150     return (word64)((word64)ByteReverseWord32((word32) value)) << 32 |
00151                     (word64)ByteReverseWord32((word32)(value   >> 32));
00152 #else
00153     value = ((value & W64LIT(0xFF00FF00FF00FF00)) >> 8) |
00154             ((value & W64LIT(0x00FF00FF00FF00FF)) << 8);
00155     value = ((value & W64LIT(0xFFFF0000FFFF0000)) >> 16) |
00156             ((value & W64LIT(0x0000FFFF0000FFFF)) << 16);
00157     return rotlFixed64(value, 32U);
00158 #endif
00159 }
00160 
00161 
00162 STATIC WC_INLINE void ByteReverseWords64(word64* out, const word64* in,
00163                                       word32 byteCount)
00164 {
00165     word32 count = byteCount/(word32)sizeof(word64), i;
00166 
00167     for (i = 0; i < count; i++)
00168         out[i] = ByteReverseWord64(in[i]);
00169 
00170 }
00171 
00172 #endif /* WORD64_AVAILABLE */
00173 
00174 
00175 STATIC WC_INLINE void XorWords(wolfssl_word* r, const wolfssl_word* a, word32 n)
00176 {
00177     word32 i;
00178 
00179     for (i = 0; i < n; i++) r[i] ^= a[i];
00180 }
00181 
00182 
00183 STATIC WC_INLINE void xorbuf(void* buf, const void* mask, word32 count)
00184 {
00185     if (((wolfssl_word)buf | (wolfssl_word)mask | count) % WOLFSSL_WORD_SIZE == 0)
00186         XorWords( (wolfssl_word*)buf,
00187                   (const wolfssl_word*)mask, count / WOLFSSL_WORD_SIZE);
00188     else {
00189         word32 i;
00190         byte*       b = (byte*)buf;
00191         const byte* m = (const byte*)mask;
00192 
00193         for (i = 0; i < count; i++) b[i] ^= m[i];
00194     }
00195 }
00196 
00197 
00198 /* Make sure compiler doesn't skip */
00199 STATIC WC_INLINE void ForceZero(const void* mem, word32 len)
00200 {
00201     volatile byte* z = (volatile byte*)mem;
00202 
00203 #if defined(WOLFSSL_X86_64_BUILD) && defined(WORD64_AVAILABLE)
00204     volatile word64* w;
00205     #ifndef WOLFSSL_UNALIGNED_64BIT_ACCESS
00206         word32 l = (sizeof(word64) - ((size_t)z & (sizeof(word64)-1))) &
00207                                                              (sizeof(word64)-1);
00208 
00209         if (len < l) l = len;
00210         len -= l;
00211         while (l--) *z++ = 0;
00212     #endif
00213     for (w = (volatile word64*)z; len >= sizeof(*w); len -= sizeof(*w))
00214         *w++ = 0;
00215     z = (volatile byte*)w;
00216 #endif
00217 
00218     while (len--) *z++ = 0;
00219 }
00220 
00221 
00222 /* check all length bytes for equality, return 0 on success */
00223 STATIC WC_INLINE int ConstantCompare(const byte* a, const byte* b, int length)
00224 {
00225     int i;
00226     int compareSum = 0;
00227 
00228     for (i = 0; i < length; i++) {
00229         compareSum |= a[i] ^ b[i];
00230     }
00231 
00232     return compareSum;
00233 }
00234 
00235 
00236 #ifndef WOLFSSL_HAVE_MIN
00237     #define WOLFSSL_HAVE_MIN
00238     #if defined(HAVE_FIPS) && !defined(min) /* so ifdef check passes */
00239         #define min min
00240     #endif
00241     STATIC WC_INLINE word32 min(word32 a, word32 b)
00242     {
00243         return a > b ? b : a;
00244     }
00245 #endif /* !WOLFSSL_HAVE_MIN */
00246 
00247 #ifndef WOLFSSL_HAVE_MAX
00248     #define WOLFSSL_HAVE_MAX
00249     #if defined(HAVE_FIPS) && !defined(max) /* so ifdef check passes */
00250         #define max max
00251     #endif
00252     STATIC WC_INLINE word32 max(word32 a, word32 b)
00253     {
00254         return a > b ? a : b;
00255     }
00256 #endif /* !WOLFSSL_HAVE_MAX */
00257 
00258 /* converts a 32 bit integer to 24 bit */
00259 STATIC WC_INLINE void c32to24(word32 in, word24 out)
00260 {
00261     out[0] = (in >> 16) & 0xff;
00262     out[1] = (in >>  8) & 0xff;
00263     out[2] =  in & 0xff;
00264 }
00265 
00266 /* convert 16 bit integer to opaque */
00267 STATIC WC_INLINE void c16toa(word16 wc_u16, byte* c)
00268 {
00269     c[0] = (wc_u16 >> 8) & 0xff;
00270     c[1] =  wc_u16 & 0xff;
00271 }
00272 
00273 /* convert 32 bit integer to opaque */
00274 STATIC WC_INLINE void c32toa(word32 wc_u32, byte* c)
00275 {
00276     c[0] = (wc_u32 >> 24) & 0xff;
00277     c[1] = (wc_u32 >> 16) & 0xff;
00278     c[2] = (wc_u32 >>  8) & 0xff;
00279     c[3] =  wc_u32 & 0xff;
00280 }
00281 
00282 /* convert a 24 bit integer into a 32 bit one */
00283 STATIC WC_INLINE void c24to32(const word24 wc_u24, word32* wc_u32)
00284 {
00285     *wc_u32 = (wc_u24[0] << 16) | (wc_u24[1] << 8) | wc_u24[2];
00286 }
00287 
00288 
00289 /* convert opaque to 24 bit integer */
00290 STATIC WC_INLINE void ato24(const byte* c, word32* wc_u24)
00291 {
00292     *wc_u24 = (c[0] << 16) | (c[1] << 8) | c[2];
00293 }
00294 
00295 /* convert opaque to 16 bit integer */
00296 STATIC WC_INLINE void ato16(const byte* c, word16* wc_u16)
00297 {
00298     *wc_u16 = (word16) ((c[0] << 8) | (c[1]));
00299 }
00300 
00301 /* convert opaque to 32 bit integer */
00302 STATIC WC_INLINE void ato32(const byte* c, word32* wc_u32)
00303 {
00304     *wc_u32 = ((word32)c[0] << 24) | (c[1] << 16) | (c[2] << 8) | c[3];
00305 }
00306 
00307 
00308 STATIC WC_INLINE word32 btoi(byte b)
00309 {
00310     return (word32)(b - 0x30);
00311 }
00312 
00313 
00314 /* Constant time - mask set when a > b. */
00315 STATIC WC_INLINE byte ctMaskGT(int a, int b)
00316 {
00317     return (((word32)a - b - 1) >> 31) - 1;
00318 }
00319 
00320 /* Constant time - mask set when a >= b. */
00321 STATIC WC_INLINE byte ctMaskGTE(int a, int b)
00322 {
00323     return (((word32)a - b    ) >> 31) - 1;
00324 }
00325 
00326 /* Constant time - mask set when a < b. */
00327 STATIC WC_INLINE byte ctMaskLT(int a, int b)
00328 {
00329     return (((word32)b - a - 1) >> 31) - 1;
00330 }
00331 
00332 /* Constant time - mask set when a <= b. */
00333 STATIC WC_INLINE byte ctMaskLTE(int a, int b)
00334 {
00335     return (((word32)b - a    ) >> 31) - 1;
00336 }
00337 
00338 /* Constant time - mask set when a == b. */
00339 STATIC WC_INLINE byte ctMaskEq(int a, int b)
00340 {
00341     return 0 - (a == b);
00342 }
00343 
00344 /* Constant time - select b when mask is set and a otherwise. */
00345 STATIC WC_INLINE byte ctMaskSel(byte m, byte a, byte b)
00346 {
00347     return (a & ((byte)~(word32)m)) | (b & m);
00348 }
00349 
00350 /* Constant time - bit set when a <= b. */
00351 STATIC WC_INLINE byte ctSetLTE(int a, int b)
00352 {
00353     return ((word32)a - b - 1) >> 31;
00354 }
00355 
00356 
00357 #undef STATIC
00358 
00359 #endif /* !WOLFSSL_MISC_INCLUDED && !NO_INLINE */
00360 
00361 #endif /* WOLF_CRYPT_MISC_C */
00362