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glibc  2.9
sha512.c
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00001 /* Functions to compute SHA512 message digest of files or memory blocks.
00002    according to the definition of SHA512 in FIPS 180-2.
00003    Copyright (C) 2007 Free Software Foundation, Inc.
00004    This file is part of the GNU C Library.
00005 
00006    The GNU C Library is free software; you can redistribute it and/or
00007    modify it under the terms of the GNU Lesser General Public
00008    License as published by the Free Software Foundation; either
00009    version 2.1 of the License, or (at your option) any later version.
00010 
00011    The GNU C Library is distributed in the hope that it will be useful,
00012    but WITHOUT ANY WARRANTY; without even the implied warranty of
00013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014    Lesser General Public License for more details.
00015 
00016    You should have received a copy of the GNU Lesser General Public
00017    License along with the GNU C Library; if not, write to the Free
00018    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00019    02111-1307 USA.  */
00020 
00021 /* Written by Ulrich Drepper <drepper@redhat.com>, 2007.  */
00022 
00023 #ifdef HAVE_CONFIG_H
00024 # include <config.h>
00025 #endif
00026 
00027 #include <endian.h>
00028 #include <stdlib.h>
00029 #include <string.h>
00030 #include <sys/types.h>
00031 
00032 #include "sha512.h"
00033 
00034 #if __BYTE_ORDER == __LITTLE_ENDIAN
00035 # ifdef _LIBC
00036 #  include <byteswap.h>
00037 #  define SWAP(n) bswap_64 (n)
00038 # else
00039 #  define SWAP(n) \
00040   (((n) << 56)                                   \
00041    | (((n) & 0xff00) << 40)               \
00042    | (((n) & 0xff0000) << 24)                    \
00043    | (((n) & 0xff000000) << 8)                   \
00044    | (((n) >> 8) & 0xff000000)                   \
00045    | (((n) >> 24) & 0xff0000)                    \
00046    | (((n) >> 40) & 0xff00)               \
00047    | ((n) >> 56))
00048 # endif
00049 #else
00050 # define SWAP(n) (n)
00051 #endif
00052 
00053 
00054 /* This array contains the bytes used to pad the buffer to the next
00055    64-byte boundary.  (FIPS 180-2:5.1.2)  */
00056 static const unsigned char fillbuf[128] = { 0x80, 0 /* , 0, 0, ...  */ };
00057 
00058 
00059 /* Constants for SHA512 from FIPS 180-2:4.2.3.  */
00060 static const uint64_t K[80] =
00061   {
00062     UINT64_C (0x428a2f98d728ae22), UINT64_C (0x7137449123ef65cd),
00063     UINT64_C (0xb5c0fbcfec4d3b2f), UINT64_C (0xe9b5dba58189dbbc),
00064     UINT64_C (0x3956c25bf348b538), UINT64_C (0x59f111f1b605d019),
00065     UINT64_C (0x923f82a4af194f9b), UINT64_C (0xab1c5ed5da6d8118),
00066     UINT64_C (0xd807aa98a3030242), UINT64_C (0x12835b0145706fbe),
00067     UINT64_C (0x243185be4ee4b28c), UINT64_C (0x550c7dc3d5ffb4e2),
00068     UINT64_C (0x72be5d74f27b896f), UINT64_C (0x80deb1fe3b1696b1),
00069     UINT64_C (0x9bdc06a725c71235), UINT64_C (0xc19bf174cf692694),
00070     UINT64_C (0xe49b69c19ef14ad2), UINT64_C (0xefbe4786384f25e3),
00071     UINT64_C (0x0fc19dc68b8cd5b5), UINT64_C (0x240ca1cc77ac9c65),
00072     UINT64_C (0x2de92c6f592b0275), UINT64_C (0x4a7484aa6ea6e483),
00073     UINT64_C (0x5cb0a9dcbd41fbd4), UINT64_C (0x76f988da831153b5),
00074     UINT64_C (0x983e5152ee66dfab), UINT64_C (0xa831c66d2db43210),
00075     UINT64_C (0xb00327c898fb213f), UINT64_C (0xbf597fc7beef0ee4),
00076     UINT64_C (0xc6e00bf33da88fc2), UINT64_C (0xd5a79147930aa725),
00077     UINT64_C (0x06ca6351e003826f), UINT64_C (0x142929670a0e6e70),
00078     UINT64_C (0x27b70a8546d22ffc), UINT64_C (0x2e1b21385c26c926),
00079     UINT64_C (0x4d2c6dfc5ac42aed), UINT64_C (0x53380d139d95b3df),
00080     UINT64_C (0x650a73548baf63de), UINT64_C (0x766a0abb3c77b2a8),
00081     UINT64_C (0x81c2c92e47edaee6), UINT64_C (0x92722c851482353b),
00082     UINT64_C (0xa2bfe8a14cf10364), UINT64_C (0xa81a664bbc423001),
00083     UINT64_C (0xc24b8b70d0f89791), UINT64_C (0xc76c51a30654be30),
00084     UINT64_C (0xd192e819d6ef5218), UINT64_C (0xd69906245565a910),
00085     UINT64_C (0xf40e35855771202a), UINT64_C (0x106aa07032bbd1b8),
00086     UINT64_C (0x19a4c116b8d2d0c8), UINT64_C (0x1e376c085141ab53),
00087     UINT64_C (0x2748774cdf8eeb99), UINT64_C (0x34b0bcb5e19b48a8),
00088     UINT64_C (0x391c0cb3c5c95a63), UINT64_C (0x4ed8aa4ae3418acb),
00089     UINT64_C (0x5b9cca4f7763e373), UINT64_C (0x682e6ff3d6b2b8a3),
00090     UINT64_C (0x748f82ee5defb2fc), UINT64_C (0x78a5636f43172f60),
00091     UINT64_C (0x84c87814a1f0ab72), UINT64_C (0x8cc702081a6439ec),
00092     UINT64_C (0x90befffa23631e28), UINT64_C (0xa4506cebde82bde9),
00093     UINT64_C (0xbef9a3f7b2c67915), UINT64_C (0xc67178f2e372532b),
00094     UINT64_C (0xca273eceea26619c), UINT64_C (0xd186b8c721c0c207),
00095     UINT64_C (0xeada7dd6cde0eb1e), UINT64_C (0xf57d4f7fee6ed178),
00096     UINT64_C (0x06f067aa72176fba), UINT64_C (0x0a637dc5a2c898a6),
00097     UINT64_C (0x113f9804bef90dae), UINT64_C (0x1b710b35131c471b),
00098     UINT64_C (0x28db77f523047d84), UINT64_C (0x32caab7b40c72493),
00099     UINT64_C (0x3c9ebe0a15c9bebc), UINT64_C (0x431d67c49c100d4c),
00100     UINT64_C (0x4cc5d4becb3e42b6), UINT64_C (0x597f299cfc657e2a),
00101     UINT64_C (0x5fcb6fab3ad6faec), UINT64_C (0x6c44198c4a475817)
00102   };
00103 
00104 
00105 /* Process LEN bytes of BUFFER, accumulating context into CTX.
00106    It is assumed that LEN % 128 == 0.  */
00107 static void
00108 sha512_process_block (const void *buffer, size_t len, struct sha512_ctx *ctx)
00109 {
00110   const uint64_t *words = buffer;
00111   size_t nwords = len / sizeof (uint64_t);
00112   uint64_t a = ctx->H[0];
00113   uint64_t b = ctx->H[1];
00114   uint64_t c = ctx->H[2];
00115   uint64_t d = ctx->H[3];
00116   uint64_t e = ctx->H[4];
00117   uint64_t f = ctx->H[5];
00118   uint64_t g = ctx->H[6];
00119   uint64_t h = ctx->H[7];
00120 
00121   /* First increment the byte count.  FIPS 180-2 specifies the possible
00122      length of the file up to 2^128 bits.  Here we only compute the
00123      number of bytes.  Do a double word increment.  */
00124   ctx->total[0] += len;
00125   if (ctx->total[0] < len)
00126     ++ctx->total[1];
00127 
00128   /* Process all bytes in the buffer with 128 bytes in each round of
00129      the loop.  */
00130   while (nwords > 0)
00131     {
00132       uint64_t W[80];
00133       uint64_t a_save = a;
00134       uint64_t b_save = b;
00135       uint64_t c_save = c;
00136       uint64_t d_save = d;
00137       uint64_t e_save = e;
00138       uint64_t f_save = f;
00139       uint64_t g_save = g;
00140       uint64_t h_save = h;
00141 
00142       /* Operators defined in FIPS 180-2:4.1.2.  */
00143 #define Ch(x, y, z) ((x & y) ^ (~x & z))
00144 #define Maj(x, y, z) ((x & y) ^ (x & z) ^ (y & z))
00145 #define S0(x) (CYCLIC (x, 28) ^ CYCLIC (x, 34) ^ CYCLIC (x, 39))
00146 #define S1(x) (CYCLIC (x, 14) ^ CYCLIC (x, 18) ^ CYCLIC (x, 41))
00147 #define R0(x) (CYCLIC (x, 1) ^ CYCLIC (x, 8) ^ (x >> 7))
00148 #define R1(x) (CYCLIC (x, 19) ^ CYCLIC (x, 61) ^ (x >> 6))
00149 
00150       /* It is unfortunate that C does not provide an operator for
00151         cyclic rotation.  Hope the C compiler is smart enough.  */
00152 #define CYCLIC(w, s) ((w >> s) | (w << (64 - s)))
00153 
00154       /* Compute the message schedule according to FIPS 180-2:6.3.2 step 2.  */
00155       for (unsigned int t = 0; t < 16; ++t)
00156        {
00157          W[t] = SWAP (*words);
00158          ++words;
00159        }
00160       for (unsigned int t = 16; t < 80; ++t)
00161        W[t] = R1 (W[t - 2]) + W[t - 7] + R0 (W[t - 15]) + W[t - 16];
00162 
00163       /* The actual computation according to FIPS 180-2:6.3.2 step 3.  */
00164       for (unsigned int t = 0; t < 80; ++t)
00165        {
00166          uint64_t T1 = h + S1 (e) + Ch (e, f, g) + K[t] + W[t];
00167          uint64_t T2 = S0 (a) + Maj (a, b, c);
00168          h = g;
00169          g = f;
00170          f = e;
00171          e = d + T1;
00172          d = c;
00173          c = b;
00174          b = a;
00175          a = T1 + T2;
00176        }
00177 
00178       /* Add the starting values of the context according to FIPS 180-2:6.3.2
00179         step 4.  */
00180       a += a_save;
00181       b += b_save;
00182       c += c_save;
00183       d += d_save;
00184       e += e_save;
00185       f += f_save;
00186       g += g_save;
00187       h += h_save;
00188 
00189       /* Prepare for the next round.  */
00190       nwords -= 16;
00191     }
00192 
00193   /* Put checksum in context given as argument.  */
00194   ctx->H[0] = a;
00195   ctx->H[1] = b;
00196   ctx->H[2] = c;
00197   ctx->H[3] = d;
00198   ctx->H[4] = e;
00199   ctx->H[5] = f;
00200   ctx->H[6] = g;
00201   ctx->H[7] = h;
00202 }
00203 
00204 
00205 /* Initialize structure containing state of computation.
00206    (FIPS 180-2:5.3.3)  */
00207 void
00208 __sha512_init_ctx (ctx)
00209      struct sha512_ctx *ctx;
00210 {
00211   ctx->H[0] = UINT64_C (0x6a09e667f3bcc908);
00212   ctx->H[1] = UINT64_C (0xbb67ae8584caa73b);
00213   ctx->H[2] = UINT64_C (0x3c6ef372fe94f82b);
00214   ctx->H[3] = UINT64_C (0xa54ff53a5f1d36f1);
00215   ctx->H[4] = UINT64_C (0x510e527fade682d1);
00216   ctx->H[5] = UINT64_C (0x9b05688c2b3e6c1f);
00217   ctx->H[6] = UINT64_C (0x1f83d9abfb41bd6b);
00218   ctx->H[7] = UINT64_C (0x5be0cd19137e2179);
00219 
00220   ctx->total[0] = ctx->total[1] = 0;
00221   ctx->buflen = 0;
00222 }
00223 
00224 
00225 /* Process the remaining bytes in the internal buffer and the usual
00226    prolog according to the standard and write the result to RESBUF.
00227 
00228    IMPORTANT: On some systems it is required that RESBUF is correctly
00229    aligned for a 32 bits value.  */
00230 void *
00231 __sha512_finish_ctx (ctx, resbuf)
00232      struct sha512_ctx *ctx;
00233      void *resbuf;
00234 {
00235   /* Take yet unprocessed bytes into account.  */
00236   uint64_t bytes = ctx->buflen;
00237   size_t pad;
00238 
00239   /* Now count remaining bytes.  */
00240   ctx->total[0] += bytes;
00241   if (ctx->total[0] < bytes)
00242     ++ctx->total[1];
00243 
00244   pad = bytes >= 112 ? 128 + 112 - bytes : 112 - bytes;
00245   memcpy (&ctx->buffer[bytes], fillbuf, pad);
00246 
00247   /* Put the 128-bit file length in *bits* at the end of the buffer.  */
00248   *(uint64_t *) &ctx->buffer[bytes + pad + 8] = SWAP (ctx->total[0] << 3);
00249   *(uint64_t *) &ctx->buffer[bytes + pad] = SWAP ((ctx->total[1] << 3) |
00250                                             (ctx->total[0] >> 61));
00251 
00252   /* Process last bytes.  */
00253   sha512_process_block (ctx->buffer, bytes + pad + 16, ctx);
00254 
00255   /* Put result from CTX in first 64 bytes following RESBUF.  */
00256   for (unsigned int i = 0; i < 8; ++i)
00257     ((uint64_t *) resbuf)[i] = SWAP (ctx->H[i]);
00258 
00259   return resbuf;
00260 }
00261 
00262 
00263 void
00264 __sha512_process_bytes (buffer, len, ctx)
00265      const void *buffer;
00266      size_t len;
00267      struct sha512_ctx *ctx;
00268 {
00269   /* When we already have some bits in our internal buffer concatenate
00270      both inputs first.  */
00271   if (ctx->buflen != 0)
00272     {
00273       size_t left_over = ctx->buflen;
00274       size_t add = 256 - left_over > len ? len : 256 - left_over;
00275 
00276       memcpy (&ctx->buffer[left_over], buffer, add);
00277       ctx->buflen += add;
00278 
00279       if (ctx->buflen > 128)
00280        {
00281          sha512_process_block (ctx->buffer, ctx->buflen & ~127, ctx);
00282 
00283          ctx->buflen &= 127;
00284          /* The regions in the following copy operation cannot overlap.  */
00285          memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~127],
00286                 ctx->buflen);
00287        }
00288 
00289       buffer = (const char *) buffer + add;
00290       len -= add;
00291     }
00292 
00293   /* Process available complete blocks.  */
00294   if (len >= 128)
00295     {
00296 #if !_STRING_ARCH_unaligned
00297 /* To check alignment gcc has an appropriate operator.  Other
00298    compilers don't.  */
00299 # if __GNUC__ >= 2
00300 #  define UNALIGNED_P(p) (((uintptr_t) p) % __alignof__ (uint64_t) != 0)
00301 # else
00302 #  define UNALIGNED_P(p) (((uintptr_t) p) % sizeof (uint64_t) != 0)
00303 # endif
00304       if (UNALIGNED_P (buffer))
00305        while (len > 128)
00306          {
00307            sha512_process_block (memcpy (ctx->buffer, buffer, 128), 128,
00308                                 ctx);
00309            buffer = (const char *) buffer + 128;
00310            len -= 128;
00311          }
00312       else
00313 #endif
00314        {
00315          sha512_process_block (buffer, len & ~127, ctx);
00316          buffer = (const char *) buffer + (len & ~127);
00317          len &= 127;
00318        }
00319     }
00320 
00321   /* Move remaining bytes into internal buffer.  */
00322   if (len > 0)
00323     {
00324       size_t left_over = ctx->buflen;
00325 
00326       memcpy (&ctx->buffer[left_over], buffer, len);
00327       left_over += len;
00328       if (left_over >= 128)
00329        {
00330          sha512_process_block (ctx->buffer, 128, ctx);
00331          left_over -= 128;
00332          memcpy (ctx->buffer, &ctx->buffer[128], left_over);
00333        }
00334       ctx->buflen = left_over;
00335     }
00336 }