lib/sha1.c

   1 /*
   2  * This file is from the Apache Portable Runtime Library.
   3  * The full upstream copyright and license statement is included below.
   4  * Modifications copyright (c) 2009 Nicira Networks.
   5  */
   6
   7 /* Licensed to the Apache Software Foundation (ASF) under one or more
   8  * contributor license agreements.  See the NOTICE file distributed with
   9  * this work for additional information regarding copyright ownership.
  10  * The ASF licenses this file to You under the Apache License, Version 2.0
  11  * (the "License"); you may not use this file except in compliance with
  12  * the License.  You may obtain a copy of the License at
  13  *
  14  *     http://www.apache.org/licenses/LICENSE-2.0
  15  *
  16  * Unless required by applicable law or agreed to in writing, software
  17  * distributed under the License is distributed on an "AS IS" BASIS,
  18  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  19  * See the License for the specific language governing permissions and
  20  * limitations under the License.
  21  */
  22
  23 /* This software also makes use of the following component:
  24  *
  25  * NIST Secure Hash Algorithm
  26  *      heavily modified by Uwe Hollerbach uh@alumni.caltech edu
  27  *      from Peter C. Gutmann's implementation as found in
  28  *      Applied Cryptography by Bruce Schneier
  29  *      This code is hereby placed in the public domain
  30  */
  31
  32 #include <config.h>
  33 #include "sha1.h"
  34 #include <string.h>
  35
  36 /* a bit faster & bigger, if defined */
  37 #define UNROLL_LOOPS
  38
  39 /* SHA f()-functions */
  40 static inline uint32_t
  41 f1(uint32_t x, uint32_t y, uint32_t z)
  42 {
  43     return (x & y) | (~x & z);
  44 }
  45
  46 static inline uint32_t
  47 f2(uint32_t x, uint32_t y, uint32_t z)
  48 {
  49     return x ^ y ^ z;
  50 }
  51
  52 static inline uint32_t
  53 f3(uint32_t x, uint32_t y, uint32_t z)
  54 {
  55     return (x & y) | (x & z) | (y & z);
  56 }
  57
  58 static inline uint32_t
  59 f4(uint32_t x, uint32_t y, uint32_t z)
  60 {
  61     return x ^ y ^ z;
  62 }
  63
  64 /* SHA constants */
  65 #define CONST1          0x5a827999L
  66 #define CONST2          0x6ed9eba1L
  67 #define CONST3          0x8f1bbcdcL
  68 #define CONST4          0xca62c1d6L
  69
  70 /* 32-bit rotate */
  71 static inline uint32_t
  72 rotate32(uint32_t x, int n)
  73 {
  74     return ((x << n) | (x >> (32 - n)));
  75 }
  76
  77 #define FUNC(n, i)                                                      \
  78     do {                                                                \
  79         temp = rotate32(A, 5) + f##n(B, C, D) + E + W[i] + CONST##n;    \
  80         E = D;                                                          \
  81         D = C;                                                          \
  82         C = rotate32(B, 30);                                            \
  83         B = A;                                                          \
  84         A = temp;                                                       \
  85     } while (0)
  86
  87 #define SHA_BLOCK_SIZE           64
  88
  89 /* Do SHA transformation. */
  90 static void
  91 sha_transform(struct sha1_ctx *sha_info)
  92 {
  93     int i;
  94     uint32_t temp, A, B, C, D, E, W[80];
  95
  96     for (i = 0; i < 16; ++i) {
  97         W[i] = sha_info->data[i];
  98     }
  99     for (i = 16; i < 80; ++i) {
 100         W[i] = W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16];
 101         W[i] = rotate32(W[i], 1);
 102     }
 103     A = sha_info->digest[0];
 104     B = sha_info->digest[1];
 105     C = sha_info->digest[2];
 106     D = sha_info->digest[3];
 107     E = sha_info->digest[4];
 108 #ifdef UNROLL_LOOPS
 109     FUNC(1, 0);  FUNC(1, 1);  FUNC(1, 2);  FUNC(1, 3);  FUNC(1, 4);
 110     FUNC(1, 5);  FUNC(1, 6);  FUNC(1, 7);  FUNC(1, 8);  FUNC(1, 9);
 111     FUNC(1,10);  FUNC(1,11);  FUNC(1,12);  FUNC(1,13);  FUNC(1,14);
 112     FUNC(1,15);  FUNC(1,16);  FUNC(1,17);  FUNC(1,18);  FUNC(1,19);
 113
 114     FUNC(2,20);  FUNC(2,21);  FUNC(2,22);  FUNC(2,23);  FUNC(2,24);
 115     FUNC(2,25);  FUNC(2,26);  FUNC(2,27);  FUNC(2,28);  FUNC(2,29);
 116     FUNC(2,30);  FUNC(2,31);  FUNC(2,32);  FUNC(2,33);  FUNC(2,34);
 117     FUNC(2,35);  FUNC(2,36);  FUNC(2,37);  FUNC(2,38);  FUNC(2,39);
 118
 119     FUNC(3,40);  FUNC(3,41);  FUNC(3,42);  FUNC(3,43);  FUNC(3,44);
 120     FUNC(3,45);  FUNC(3,46);  FUNC(3,47);  FUNC(3,48);  FUNC(3,49);
 121     FUNC(3,50);  FUNC(3,51);  FUNC(3,52);  FUNC(3,53);  FUNC(3,54);
 122     FUNC(3,55);  FUNC(3,56);  FUNC(3,57);  FUNC(3,58);  FUNC(3,59);
 123
 124     FUNC(4,60);  FUNC(4,61);  FUNC(4,62);  FUNC(4,63);  FUNC(4,64);
 125     FUNC(4,65);  FUNC(4,66);  FUNC(4,67);  FUNC(4,68);  FUNC(4,69);
 126     FUNC(4,70);  FUNC(4,71);  FUNC(4,72);  FUNC(4,73);  FUNC(4,74);
 127     FUNC(4,75);  FUNC(4,76);  FUNC(4,77);  FUNC(4,78);  FUNC(4,79);
 128 #else /* !UNROLL_LOOPS */
 129     for (i = 0; i < 20; ++i) {
 130         FUNC(1,i);
 131     }
 132     for (i = 20; i < 40; ++i) {
 133         FUNC(2,i);
 134     }
 135     for (i = 40; i < 60; ++i) {
 136         FUNC(3,i);
 137     }
 138     for (i = 60; i < 80; ++i) {
 139         FUNC(4,i);
 140     }
 141 #endif /* !UNROLL_LOOPS */
 142     sha_info->digest[0] += A;
 143     sha_info->digest[1] += B;
 144     sha_info->digest[2] += C;
 145     sha_info->digest[3] += D;
 146     sha_info->digest[4] += E;
 147 }
 148
 149 /* 'count' is the number of bytes to do an endian flip. */
 150 static void
 151 maybe_byte_reverse(uint32_t *buffer, int count)
 152 {
 153     int i;
 154     uint8_t ct[4], *cp;
 155
 156 #if !WORDS_BIGENDIAN
 157         count /= sizeof(uint32_t);
 158         cp = (uint8_t *) buffer;
 159         for (i = 0; i < count; i++) {
 160             ct[0] = cp[0];
 161             ct[1] = cp[1];
 162             ct[2] = cp[2];
 163             ct[3] = cp[3];
 164             cp[0] = ct[3];
 165             cp[1] = ct[2];
 166             cp[2] = ct[1];
 167             cp[3] = ct[0];
 168             cp += sizeof(uint32_t);
 169         }
 170 #endif
 171 }
 172
 173 /*
 174  * Initialize the SHA digest.
 175  * context: The SHA context to initialize
 176  */
 177 void
 178 sha1_init(struct sha1_ctx *sha_info)
 179 {
 180     sha_info->digest[0] = 0x67452301L;
 181     sha_info->digest[1] = 0xefcdab89L;
 182     sha_info->digest[2] = 0x98badcfeL;
 183     sha_info->digest[3] = 0x10325476L;
 184     sha_info->digest[4] = 0xc3d2e1f0L;
 185     sha_info->count_lo = 0L;
 186     sha_info->count_hi = 0L;
 187     sha_info->local = 0;
 188 }
 189
 190 /*
 191  * Update the SHA digest.
 192  * context: The SHA1 context to update.
 193  * input: The buffer to add to the SHA digest.
 194  * inputLen: The length of the input buffer.
 195  */
 196 void
 197 sha1_update(struct sha1_ctx *ctx, const void *buffer_, size_t count)
 198 {
 199     const uint8_t *buffer = buffer_;
 200     unsigned int i;
 201
 202     if ((ctx->count_lo + (count << 3)) < ctx->count_lo) {
 203         ctx->count_hi++;
 204     }
 205     ctx->count_lo += count << 3;
 206     ctx->count_hi += count >> 29;
 207     if (ctx->local) {
 208         i = SHA_BLOCK_SIZE - ctx->local;
 209         if (i > count) {
 210             i = count;
 211         }
 212         memcpy(((uint8_t *) ctx->data) + ctx->local, buffer, i);
 213         count -= i;
 214         buffer += i;
 215         ctx->local += i;
 216         if (ctx->local == SHA_BLOCK_SIZE) {
 217             maybe_byte_reverse(ctx->data, SHA_BLOCK_SIZE);
 218             sha_transform(ctx);
 219         } else {
 220             return;
 221         }
 222     }
 223     while (count >= SHA_BLOCK_SIZE) {
 224         memcpy(ctx->data, buffer, SHA_BLOCK_SIZE);
 225         buffer += SHA_BLOCK_SIZE;
 226         count -= SHA_BLOCK_SIZE;
 227         maybe_byte_reverse(ctx->data, SHA_BLOCK_SIZE);
 228         sha_transform(ctx);
 229     }
 230     memcpy(ctx->data, buffer, count);
 231     ctx->local = count;
 232 }
 233
 234 /*
 235  * Finish computing the SHA digest.
 236  * digest: the output buffer in which to store the digest.
 237  * context: The context to finalize.
 238  */
 239 void
 240 sha1_final(struct sha1_ctx *ctx, uint8_t digest[SHA1_DIGEST_SIZE])
 241 {
 242     int count, i, j;
 243     uint32_t lo_bit_count, hi_bit_count, k;
 244
 245     lo_bit_count = ctx->count_lo;
 246     hi_bit_count = ctx->count_hi;
 247     count = (int) ((lo_bit_count >> 3) & 0x3f);
 248     ((uint8_t *) ctx->data)[count++] = 0x80;
 249     if (count > SHA_BLOCK_SIZE - 8) {
 250         memset(((uint8_t *) ctx->data) + count, 0, SHA_BLOCK_SIZE - count);
 251         maybe_byte_reverse(ctx->data, SHA_BLOCK_SIZE);
 252         sha_transform(ctx);
 253         memset((uint8_t *) ctx->data, 0, SHA_BLOCK_SIZE - 8);
 254     } else {
 255         memset(((uint8_t *) ctx->data) + count, 0,
 256                SHA_BLOCK_SIZE - 8 - count);
 257     }
 258     maybe_byte_reverse(ctx->data, SHA_BLOCK_SIZE);
 259     ctx->data[14] = hi_bit_count;
 260     ctx->data[15] = lo_bit_count;
 261     sha_transform(ctx);
 262
 263     for (i = j = 0; j < SHA1_DIGEST_SIZE; i++) {
 264         k = ctx->digest[i];
 265         digest[j++] = k >> 24;
 266         digest[j++] = k >> 16;
 267         digest[j++] = k >> 8;
 268         digest[j++] = k;
 269     }
 270 }
 271
 272 /* Computes the hash of 'n' bytes in 'data' into 'digest'. */
 273 void
 274 sha1_bytes(const void *data, size_t n, uint8_t digest[SHA1_DIGEST_SIZE])
 275 {
 276     struct sha1_ctx ctx;
 277
 278     sha1_init(&ctx);
 279     sha1_update(&ctx, data, n);
 280     sha1_final(&ctx, digest);
 281 }