src/crypto/sha256-internal.c

   1 /*
   2  * SHA-256 hash implementation and interface functions
   3  * Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #include "includes.h"
  16
  17 #include "common.h"
  18 #include "sha256.h"
  19 #include "crypto.h"
  20
  21 struct sha256_state {
  22         u64 length;
  23         u32 state[8], curlen;
  24         u8 buf[64];
  25 };
  26
  27 static void sha256_init(struct sha256_state *md);
  28 static int sha256_process(struct sha256_state *md, const unsigned char *in,
  29                           unsigned long inlen);
  30 static int sha256_done(struct sha256_state *md, unsigned char *out);
  31
  32
  33 /**
  34  * sha256_vector - SHA256 hash for data vector
  35  * @num_elem: Number of elements in the data vector
  36  * @addr: Pointers to the data areas
  37  * @len: Lengths of the data blocks
  38  * @mac: Buffer for the hash
  39  * Returns: 0 on success, -1 of failure
  40  */
  41 int sha256_vector(size_t num_elem, const u8 *addr[], const size_t *len,
  42                   u8 *mac)
  43 {
  44         struct sha256_state ctx;
  45         size_t i;
  46
  47         sha256_init(&ctx);
  48         for (i = 0; i < num_elem; i++)
  49                 if (sha256_process(&ctx, addr[i], len[i]))
  50                         return -1;
  51         if (sha256_done(&ctx, mac))
  52                 return -1;
  53         return 0;
  54 }
  55
  56
  57 /* ===== start - public domain SHA256 implementation ===== */
  58
  59 /* This is based on SHA256 implementation in LibTomCrypt that was released into
  60  * public domain by Tom St Denis. */
  61
  62 /* the K array */
  63 static const unsigned long K[64] = {
  64         0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL, 0x3956c25bUL,
  65         0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL, 0xd807aa98UL, 0x12835b01UL,
  66         0x243185beUL, 0x550c7dc3UL, 0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL,
  67         0xc19bf174UL, 0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
  68         0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL, 0x983e5152UL,
  69         0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL, 0xc6e00bf3UL, 0xd5a79147UL,
  70         0x06ca6351UL, 0x14292967UL, 0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL,
  71         0x53380d13UL, 0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
  72         0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL, 0xd192e819UL,
  73         0xd6990624UL, 0xf40e3585UL, 0x106aa070UL, 0x19a4c116UL, 0x1e376c08UL,
  74         0x2748774cUL, 0x34b0bcb5UL, 0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL,
  75         0x682e6ff3UL, 0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
  76         0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL
  77 };
  78
  79
  80 /* Various logical functions */
  81 #define RORc(x, y) \
  82 ( ((((unsigned long) (x) & 0xFFFFFFFFUL) >> (unsigned long) ((y) & 31)) | \
  83    ((unsigned long) (x) << (unsigned long) (32 - ((y) & 31)))) & 0xFFFFFFFFUL)
  84 #define Ch(x,y,z)       (z ^ (x & (y ^ z)))
  85 #define Maj(x,y,z)      (((x | y) & z) | (x & y))
  86 #define S(x, n)         RORc((x), (n))
  87 #define R(x, n)         (((x)&0xFFFFFFFFUL)>>(n))
  88 #define Sigma0(x)       (S(x, 2) ^ S(x, 13) ^ S(x, 22))
  89 #define Sigma1(x)       (S(x, 6) ^ S(x, 11) ^ S(x, 25))
  90 #define Gamma0(x)       (S(x, 7) ^ S(x, 18) ^ R(x, 3))
  91 #define Gamma1(x)       (S(x, 17) ^ S(x, 19) ^ R(x, 10))
  92 #ifndef MIN
  93 #define MIN(x, y) (((x) < (y)) ? (x) : (y))
  94 #endif
  95
  96 /* compress 512-bits */
  97 static int sha256_compress(struct sha256_state *md, unsigned char *buf)
  98 {
  99         u32 S[8], W[64], t0, t1;
 100         u32 t;
 101         int i;
 102
 103         /* copy state into S */
 104         for (i = 0; i < 8; i++) {
 105                 S[i] = md->state[i];
 106         }
 107
 108         /* copy the state into 512-bits into W[0..15] */
 109         for (i = 0; i < 16; i++)
 110                 W[i] = WPA_GET_BE32(buf + (4 * i));
 111
 112         /* fill W[16..63] */
 113         for (i = 16; i < 64; i++) {
 114                 W[i] = Gamma1(W[i - 2]) + W[i - 7] + Gamma0(W[i - 15]) +
 115                         W[i - 16];
 116         }
 117
 118         /* Compress */
 119 #define RND(a,b,c,d,e,f,g,h,i)                          \
 120         t0 = h + Sigma1(e) + Ch(e, f, g) + K[i] + W[i]; \
 121         t1 = Sigma0(a) + Maj(a, b, c);                  \
 122         d += t0;                                        \
 123         h  = t0 + t1;
 124
 125         for (i = 0; i < 64; ++i) {
 126                 RND(S[0], S[1], S[2], S[3], S[4], S[5], S[6], S[7], i);
 127                 t = S[7]; S[7] = S[6]; S[6] = S[5]; S[5] = S[4];
 128                 S[4] = S[3]; S[3] = S[2]; S[2] = S[1]; S[1] = S[0]; S[0] = t;
 129         }
 130
 131         /* feedback */
 132         for (i = 0; i < 8; i++) {
 133                 md->state[i] = md->state[i] + S[i];
 134         }
 135         return 0;
 136 }
 137
 138
 139 /* Initialize the hash state */
 140 static void sha256_init(struct sha256_state *md)
 141 {
 142         md->curlen = 0;
 143         md->length = 0;
 144         md->state[0] = 0x6A09E667UL;
 145         md->state[1] = 0xBB67AE85UL;
 146         md->state[2] = 0x3C6EF372UL;
 147         md->state[3] = 0xA54FF53AUL;
 148         md->state[4] = 0x510E527FUL;
 149         md->state[5] = 0x9B05688CUL;
 150         md->state[6] = 0x1F83D9ABUL;
 151         md->state[7] = 0x5BE0CD19UL;
 152 }
 153
 154 /**
 155    Process a block of memory though the hash
 156    @param md     The hash state
 157    @param in     The data to hash
 158    @param inlen  The length of the data (octets)
 159    @return CRYPT_OK if successful
 160 */
 161 static int sha256_process(struct sha256_state *md, const unsigned char *in,
 162                           unsigned long inlen)
 163 {
 164         unsigned long n;
 165 #define block_size 64
 166
 167         if (md->curlen > sizeof(md->buf))
 168                 return -1;
 169
 170         while (inlen > 0) {
 171                 if (md->curlen == 0 && inlen >= block_size) {
 172                         if (sha256_compress(md, (unsigned char *) in) < 0)
 173                                 return -1;
 174                         md->length += block_size * 8;
 175                         in += block_size;
 176                         inlen -= block_size;
 177                 } else {
 178                         n = MIN(inlen, (block_size - md->curlen));
 179                         os_memcpy(md->buf + md->curlen, in, n);
 180                         md->curlen += n;
 181                         in += n;
 182                         inlen -= n;
 183                         if (md->curlen == block_size) {
 184                                 if (sha256_compress(md, md->buf) < 0)
 185                                         return -1;
 186                                 md->length += 8 * block_size;
 187                                 md->curlen = 0;
 188                         }
 189                 }
 190         }
 191
 192         return 0;
 193 }
 194
 195
 196 /**
 197    Terminate the hash to get the digest
 198    @param md  The hash state
 199    @param out [out] The destination of the hash (32 bytes)
 200    @return CRYPT_OK if successful
 201 */
 202 static int sha256_done(struct sha256_state *md, unsigned char *out)
 203 {
 204         int i;
 205
 206         if (md->curlen >= sizeof(md->buf))
 207                 return -1;
 208
 209         /* increase the length of the message */
 210         md->length += md->curlen * 8;
 211
 212         /* append the '1' bit */
 213         md->buf[md->curlen++] = (unsigned char) 0x80;
 214
 215         /* if the length is currently above 56 bytes we append zeros
 216          * then compress.  Then we can fall back to padding zeros and length
 217          * encoding like normal.
 218          */
 219         if (md->curlen > 56) {
 220                 while (md->curlen < 64) {
 221                         md->buf[md->curlen++] = (unsigned char) 0;
 222                 }
 223                 sha256_compress(md, md->buf);
 224                 md->curlen = 0;
 225         }
 226
 227         /* pad upto 56 bytes of zeroes */
 228         while (md->curlen < 56) {
 229                 md->buf[md->curlen++] = (unsigned char) 0;
 230         }
 231
 232         /* store length */
 233         WPA_PUT_BE64(md->buf + 56, md->length);
 234         sha256_compress(md, md->buf);
 235
 236         /* copy output */
 237         for (i = 0; i < 8; i++)
 238                 WPA_PUT_BE32(out + (4 * i), md->state[i]);
 239
 240         return 0;
 241 }
 242
 243 /* ===== end - public domain SHA256 implementation ===== */