lib/libmd/sha256c.c

   1 /*-
   2  * Copyright 2005 Colin Percival
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $FreeBSD: src/lib/libmd/sha256c.c,v 1.2 2006/01/17 15:35:56 phk Exp $
  27  */
  28
  29 #include <sys/endian.h>
  30 #include <sys/types.h>
  31
  32 #include <string.h>
  33
  34 #include "sha256.h"
  35
  36 #if BYTE_ORDER == BIG_ENDIAN
  37
  38 /* Copy a vector of big-endian uint32_t into a vector of bytes */
  39 #define be32enc_vect(dst, src, len)     \
  40         memcpy((void *)dst, (const void *)src, (size_t)len)
  41
  42 /* Copy a vector of bytes into a vector of big-endian uint32_t */
  43 #define be32dec_vect(dst, src, len)     \
  44         memcpy((void *)dst, (const void *)src, (size_t)len)
  45
  46 #else /* BYTE_ORDER != BIG_ENDIAN */
  47
  48 /*
  49  * Encode a length len/4 vector of (uint32_t) into a length len vector of
  50  * (unsigned char) in big-endian form.  Assumes len is a multiple of 4.
  51  */
  52 static void
  53 be32enc_vect(unsigned char *dst, const uint32_t *src, size_t len)
  54 {
  55         size_t i;
  56
  57         for (i = 0; i < len / 4; i++)
  58                 be32enc(dst + i * 4, src[i]);
  59 }
  60
  61 /*
  62  * Decode a big-endian length len vector of (unsigned char) into a length
  63  * len/4 vector of (uint32_t).  Assumes len is a multiple of 4.
  64  */
  65 static void
  66 be32dec_vect(uint32_t *dst, const unsigned char *src, size_t len)
  67 {
  68         size_t i;
  69
  70         for (i = 0; i < len / 4; i++)
  71                 dst[i] = be32dec(src + i * 4);
  72 }
  73
  74 #endif /* BYTE_ORDER != BIG_ENDIAN */
  75
  76 /* Elementary functions used by SHA256 */
  77 #define Ch(x, y, z)     ((x & (y ^ z)) ^ z)
  78 #define Maj(x, y, z)    ((x & (y | z)) | (y & z))
  79 #define SHR(x, n)       (x >> n)
  80 #define ROTR(x, n)      ((x >> n) | (x << (32 - n)))
  81 #define S0(x)           (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22))
  82 #define S1(x)           (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25))
  83 #define s0(x)           (ROTR(x, 7) ^ ROTR(x, 18) ^ SHR(x, 3))
  84 #define s1(x)           (ROTR(x, 17) ^ ROTR(x, 19) ^ SHR(x, 10))
  85
  86 /* SHA256 round function */
  87 #define RND(a, b, c, d, e, f, g, h, k)                  \
  88         t0 = h + S1(e) + Ch(e, f, g) + k;               \
  89         t1 = S0(a) + Maj(a, b, c);                      \
  90         d += t0;                                        \
  91         h  = t0 + t1;
  92
  93 /* Adjusted round function for rotating state */
  94 #define RNDr(S, W, i, k)                        \
  95         RND(S[(64 - i) % 8], S[(65 - i) % 8],   \
  96             S[(66 - i) % 8], S[(67 - i) % 8],   \
  97             S[(68 - i) % 8], S[(69 - i) % 8],   \
  98             S[(70 - i) % 8], S[(71 - i) % 8],   \
  99             W[i] + k)
 100
 101 /*
 102  * SHA256 block compression function.  The 256-bit state is transformed via
 103  * the 512-bit input block to produce a new state.
 104  */
 105 static void
 106 SHA256_Transform(uint32_t * state, const unsigned char block[64])
 107 {
 108         uint32_t W[64];
 109         uint32_t S[8];
 110         uint32_t t0, t1;
 111         int i;
 112
 113         /* 1. Prepare message schedule W. */
 114         be32dec_vect(W, block, 64);
 115         for (i = 16; i < 64; i++)
 116                 W[i] = s1(W[i - 2]) + W[i - 7] + s0(W[i - 15]) + W[i - 16];
 117
 118         /* 2. Initialize working variables. */
 119         memcpy(S, state, 32);
 120
 121         /* 3. Mix. */
 122         RNDr(S, W, 0, 0x428a2f98);
 123         RNDr(S, W, 1, 0x71374491);
 124         RNDr(S, W, 2, 0xb5c0fbcf);
 125         RNDr(S, W, 3, 0xe9b5dba5);
 126         RNDr(S, W, 4, 0x3956c25b);
 127         RNDr(S, W, 5, 0x59f111f1);
 128         RNDr(S, W, 6, 0x923f82a4);
 129         RNDr(S, W, 7, 0xab1c5ed5);
 130         RNDr(S, W, 8, 0xd807aa98);
 131         RNDr(S, W, 9, 0x12835b01);
 132         RNDr(S, W, 10, 0x243185be);
 133         RNDr(S, W, 11, 0x550c7dc3);
 134         RNDr(S, W, 12, 0x72be5d74);
 135         RNDr(S, W, 13, 0x80deb1fe);
 136         RNDr(S, W, 14, 0x9bdc06a7);
 137         RNDr(S, W, 15, 0xc19bf174);
 138         RNDr(S, W, 16, 0xe49b69c1);
 139         RNDr(S, W, 17, 0xefbe4786);
 140         RNDr(S, W, 18, 0x0fc19dc6);
 141         RNDr(S, W, 19, 0x240ca1cc);
 142         RNDr(S, W, 20, 0x2de92c6f);
 143         RNDr(S, W, 21, 0x4a7484aa);
 144         RNDr(S, W, 22, 0x5cb0a9dc);
 145         RNDr(S, W, 23, 0x76f988da);
 146         RNDr(S, W, 24, 0x983e5152);
 147         RNDr(S, W, 25, 0xa831c66d);
 148         RNDr(S, W, 26, 0xb00327c8);
 149         RNDr(S, W, 27, 0xbf597fc7);
 150         RNDr(S, W, 28, 0xc6e00bf3);
 151         RNDr(S, W, 29, 0xd5a79147);
 152         RNDr(S, W, 30, 0x06ca6351);
 153         RNDr(S, W, 31, 0x14292967);
 154         RNDr(S, W, 32, 0x27b70a85);
 155         RNDr(S, W, 33, 0x2e1b2138);
 156         RNDr(S, W, 34, 0x4d2c6dfc);
 157         RNDr(S, W, 35, 0x53380d13);
 158         RNDr(S, W, 36, 0x650a7354);
 159         RNDr(S, W, 37, 0x766a0abb);
 160         RNDr(S, W, 38, 0x81c2c92e);
 161         RNDr(S, W, 39, 0x92722c85);
 162         RNDr(S, W, 40, 0xa2bfe8a1);
 163         RNDr(S, W, 41, 0xa81a664b);
 164         RNDr(S, W, 42, 0xc24b8b70);
 165         RNDr(S, W, 43, 0xc76c51a3);
 166         RNDr(S, W, 44, 0xd192e819);
 167         RNDr(S, W, 45, 0xd6990624);
 168         RNDr(S, W, 46, 0xf40e3585);
 169         RNDr(S, W, 47, 0x106aa070);
 170         RNDr(S, W, 48, 0x19a4c116);
 171         RNDr(S, W, 49, 0x1e376c08);
 172         RNDr(S, W, 50, 0x2748774c);
 173         RNDr(S, W, 51, 0x34b0bcb5);
 174         RNDr(S, W, 52, 0x391c0cb3);
 175         RNDr(S, W, 53, 0x4ed8aa4a);
 176         RNDr(S, W, 54, 0x5b9cca4f);
 177         RNDr(S, W, 55, 0x682e6ff3);
 178         RNDr(S, W, 56, 0x748f82ee);
 179         RNDr(S, W, 57, 0x78a5636f);
 180         RNDr(S, W, 58, 0x84c87814);
 181         RNDr(S, W, 59, 0x8cc70208);
 182         RNDr(S, W, 60, 0x90befffa);
 183         RNDr(S, W, 61, 0xa4506ceb);
 184         RNDr(S, W, 62, 0xbef9a3f7);
 185         RNDr(S, W, 63, 0xc67178f2);
 186
 187         /* 4. Mix local working variables into global state */
 188         for (i = 0; i < 8; i++)
 189                 state[i] += S[i];
 190 }
 191
 192 static unsigned char PAD[64] = {
 193         0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 194         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 195         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 196         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
 197 };
 198
 199 /* Add padding and terminating bit-count. */
 200 static void
 201 SHA256_Pad(SHA256_CTX * ctx)
 202 {
 203         unsigned char len[8];
 204         uint32_t r, plen;
 205
 206         /*
 207          * Convert length to a vector of bytes -- we do this now rather
 208          * than later because the length will change after we pad.
 209          */
 210         be32enc_vect(len, ctx->count, 8);
 211
 212         /* Add 1--64 bytes so that the resulting length is 56 mod 64 */
 213         r = (ctx->count[1] >> 3) & 0x3f;
 214         plen = (r < 56) ? (56 - r) : (120 - r);
 215         SHA256_Update(ctx, PAD, (size_t)plen);
 216
 217         /* Add the terminating bit-count */
 218         SHA256_Update(ctx, len, 8);
 219 }
 220
 221 /* SHA-256 initialization.  Begins a SHA-256 operation. */
 222 void
 223 SHA256_Init(SHA256_CTX * ctx)
 224 {
 225
 226         /* Zero bits processed so far */
 227         ctx->count[0] = ctx->count[1] = 0;
 228
 229         /* Magic initialization constants */
 230         ctx->state[0] = 0x6A09E667;
 231         ctx->state[1] = 0xBB67AE85;
 232         ctx->state[2] = 0x3C6EF372;
 233         ctx->state[3] = 0xA54FF53A;
 234         ctx->state[4] = 0x510E527F;
 235         ctx->state[5] = 0x9B05688C;
 236         ctx->state[6] = 0x1F83D9AB;
 237         ctx->state[7] = 0x5BE0CD19;
 238 }
 239
 240 /* Add bytes into the hash */
 241 void
 242 SHA256_Update(SHA256_CTX * ctx, const void *in, size_t len)
 243 {
 244         uint32_t bitlen[2];
 245         uint32_t r;
 246         const unsigned char *src = in;
 247
 248         /* Number of bytes left in the buffer from previous updates */
 249         r = (ctx->count[1] >> 3) & 0x3f;
 250
 251         /* Convert the length into a number of bits */
 252         bitlen[1] = ((uint32_t)len) << 3;
 253         bitlen[0] = (uint32_t)(len >> 29);
 254
 255         /* Update number of bits */
 256         if ((ctx->count[1] += bitlen[1]) < bitlen[1])
 257                 ctx->count[0]++;
 258         ctx->count[0] += bitlen[0];
 259
 260         /* Handle the case where we don't need to perform any transforms */
 261         if (len < 64 - r) {
 262                 memcpy(&ctx->buf[r], src, len);
 263                 return;
 264         }
 265
 266         /* Finish the current block */
 267         memcpy(&ctx->buf[r], src, 64 - r);
 268         SHA256_Transform(ctx->state, ctx->buf);
 269         src += 64 - r;
 270         len -= 64 - r;
 271
 272         /* Perform complete blocks */
 273         while (len >= 64) {
 274                 SHA256_Transform(ctx->state, src);
 275                 src += 64;
 276                 len -= 64;
 277         }
 278
 279         /* Copy left over data into buffer */
 280         memcpy(ctx->buf, src, len);
 281 }
 282
 283 /*
 284  * SHA-256 finalization.  Pads the input data, exports the hash value,
 285  * and clears the context state.
 286  */
 287 void
 288 SHA256_Final(unsigned char digest[32], SHA256_CTX * ctx)
 289 {
 290
 291         /* Add padding */
 292         SHA256_Pad(ctx);
 293
 294         /* Write the hash */
 295         be32enc_vect(digest, ctx->state, 32);
 296
 297         /* Clear the context state */
 298         memset((void *)ctx, 0, sizeof(*ctx));
 299 }