2 * SHA1 hash algorithm. Used in SSH-2 as a MAC, and the transform is
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3 * also used as a `stirring' function for the PuTTY random number
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4 * pool. Implemented directly from the specification by Simon
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10 /* ----------------------------------------------------------------------
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11 * Core SHA algorithm: processes 16-word blocks into a message digest.
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14 #define rol(x,y) ( ((x) << (y)) | (((uint32)x) >> (32-y)) )
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16 static void SHA_Core_Init(uint32 h[5])
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25 void SHATransform(word32 * digest, word32 * block)
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28 word32 a, b, c, d, e;
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31 #ifdef RANDOM_DIAGNOSTICS
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33 extern int random_diagnostics;
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34 if (random_diagnostics) {
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36 printf("SHATransform:");
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37 for (i = 0; i < 5; i++)
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38 printf(" %08x", digest[i]);
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40 for (i = 0; i < 16; i++)
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41 printf(" %08x", block[i]);
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46 for (t = 0; t < 16; t++)
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49 for (t = 16; t < 80; t++) {
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50 word32 tmp = w[t - 3] ^ w[t - 8] ^ w[t - 14] ^ w[t - 16];
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60 for (t = 0; t < 20; t++) {
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62 rol(a, 5) + ((b & c) | (d & ~b)) + e + w[t] + 0x5a827999;
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69 for (t = 20; t < 40; t++) {
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70 word32 tmp = rol(a, 5) + (b ^ c ^ d) + e + w[t] + 0x6ed9eba1;
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77 for (t = 40; t < 60; t++) {
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79 5) + ((b & c) | (b & d) | (c & d)) + e + w[t] +
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87 for (t = 60; t < 80; t++) {
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88 word32 tmp = rol(a, 5) + (b ^ c ^ d) + e + w[t] + 0xca62c1d6;
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102 #ifdef RANDOM_DIAGNOSTICS
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104 extern int random_diagnostics;
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105 if (random_diagnostics) {
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108 for (i = 0; i < 5; i++)
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109 printf(" %08x", digest[i]);
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116 /* ----------------------------------------------------------------------
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117 * Outer SHA algorithm: take an arbitrary length byte string,
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118 * convert it into 16-word blocks with the prescribed padding at
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119 * the end, and pass those blocks to the core SHA algorithm.
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122 void SHA_Init(SHA_State * s)
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124 SHA_Core_Init(s->h);
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126 s->lenhi = s->lenlo = 0;
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129 void SHA_Bytes(SHA_State * s, const void *p, int len)
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131 const unsigned char *q = (const unsigned char *) p;
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132 uint32 wordblock[16];
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137 * Update the length field.
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140 s->lenhi += (s->lenlo < lenw);
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142 if (s->blkused && s->blkused + len < 64) {
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144 * Trivial case: just add to the block.
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146 memcpy(s->block + s->blkused, q, len);
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150 * We must complete and process at least one block.
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152 while (s->blkused + len >= 64) {
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153 memcpy(s->block + s->blkused, q, 64 - s->blkused);
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154 q += 64 - s->blkused;
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155 len -= 64 - s->blkused;
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156 /* Now process the block. Gather bytes big-endian into words */
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157 for (i = 0; i < 16; i++) {
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159 (((uint32) s->block[i * 4 + 0]) << 24) |
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160 (((uint32) s->block[i * 4 + 1]) << 16) |
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161 (((uint32) s->block[i * 4 + 2]) << 8) |
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162 (((uint32) s->block[i * 4 + 3]) << 0);
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164 SHATransform(s->h, wordblock);
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167 memcpy(s->block, q, len);
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172 void SHA_Final(SHA_State * s, unsigned char *output)
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176 unsigned char c[64];
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177 uint32 lenhi, lenlo;
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179 if (s->blkused >= 56)
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180 pad = 56 + 64 - s->blkused;
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182 pad = 56 - s->blkused;
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184 lenhi = (s->lenhi << 3) | (s->lenlo >> (32 - 3));
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185 lenlo = (s->lenlo << 3);
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189 SHA_Bytes(s, &c, pad);
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191 c[0] = (lenhi >> 24) & 0xFF;
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192 c[1] = (lenhi >> 16) & 0xFF;
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193 c[2] = (lenhi >> 8) & 0xFF;
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194 c[3] = (lenhi >> 0) & 0xFF;
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195 c[4] = (lenlo >> 24) & 0xFF;
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196 c[5] = (lenlo >> 16) & 0xFF;
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197 c[6] = (lenlo >> 8) & 0xFF;
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198 c[7] = (lenlo >> 0) & 0xFF;
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200 SHA_Bytes(s, &c, 8);
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202 for (i = 0; i < 5; i++) {
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203 output[i * 4] = (s->h[i] >> 24) & 0xFF;
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204 output[i * 4 + 1] = (s->h[i] >> 16) & 0xFF;
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205 output[i * 4 + 2] = (s->h[i] >> 8) & 0xFF;
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206 output[i * 4 + 3] = (s->h[i]) & 0xFF;
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210 void SHA_Simple(const void *p, int len, unsigned char *output)
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215 SHA_Bytes(&s, p, len);
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216 SHA_Final(&s, output);
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220 * Thin abstraction for things where hashes are pluggable.
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223 static void *sha1_init(void)
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227 s = snew(SHA_State);
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232 static void sha1_bytes(void *handle, void *p, int len)
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234 SHA_State *s = handle;
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236 SHA_Bytes(s, p, len);
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239 static void sha1_final(void *handle, unsigned char *output)
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241 SHA_State *s = handle;
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243 SHA_Final(s, output);
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247 const struct ssh_hash ssh_sha1 = {
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248 sha1_init, sha1_bytes, sha1_final, 20, "SHA-1"
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251 /* ----------------------------------------------------------------------
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252 * The above is the SHA-1 algorithm itself. Now we implement the
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253 * HMAC wrapper on it.
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256 static void *sha1_make_context(void)
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258 return snewn(3, SHA_State);
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261 static void sha1_free_context(void *handle)
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266 static void sha1_key_internal(void *handle, unsigned char *key, int len)
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268 SHA_State *keys = (SHA_State *)handle;
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269 unsigned char foo[64];
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272 memset(foo, 0x36, 64);
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273 for (i = 0; i < len && i < 64; i++)
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275 SHA_Init(&keys[0]);
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276 SHA_Bytes(&keys[0], foo, 64);
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278 memset(foo, 0x5C, 64);
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279 for (i = 0; i < len && i < 64; i++)
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281 SHA_Init(&keys[1]);
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282 SHA_Bytes(&keys[1], foo, 64);
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284 smemclr(foo, 64); /* burn the evidence */
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287 static void sha1_key(void *handle, unsigned char *key)
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289 sha1_key_internal(handle, key, 20);
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292 static void sha1_key_buggy(void *handle, unsigned char *key)
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294 sha1_key_internal(handle, key, 16);
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297 static void hmacsha1_start(void *handle)
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299 SHA_State *keys = (SHA_State *)handle;
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301 keys[2] = keys[0]; /* structure copy */
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304 static void hmacsha1_bytes(void *handle, unsigned char const *blk, int len)
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306 SHA_State *keys = (SHA_State *)handle;
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307 SHA_Bytes(&keys[2], (void *)blk, len);
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310 static void hmacsha1_genresult(void *handle, unsigned char *hmac)
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312 SHA_State *keys = (SHA_State *)handle;
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314 unsigned char intermediate[20];
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316 s = keys[2]; /* structure copy */
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317 SHA_Final(&s, intermediate);
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318 s = keys[1]; /* structure copy */
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319 SHA_Bytes(&s, intermediate, 20);
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320 SHA_Final(&s, hmac);
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323 static void sha1_do_hmac(void *handle, unsigned char *blk, int len,
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324 unsigned long seq, unsigned char *hmac)
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326 unsigned char seqbuf[4];
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328 PUT_32BIT_MSB_FIRST(seqbuf, seq);
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329 hmacsha1_start(handle);
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330 hmacsha1_bytes(handle, seqbuf, 4);
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331 hmacsha1_bytes(handle, blk, len);
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332 hmacsha1_genresult(handle, hmac);
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335 static void sha1_generate(void *handle, unsigned char *blk, int len,
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338 sha1_do_hmac(handle, blk, len, seq, blk + len);
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341 static int hmacsha1_verresult(void *handle, unsigned char const *hmac)
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343 unsigned char correct[20];
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344 hmacsha1_genresult(handle, correct);
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345 return !memcmp(correct, hmac, 20);
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348 static int sha1_verify(void *handle, unsigned char *blk, int len,
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351 unsigned char correct[20];
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352 sha1_do_hmac(handle, blk, len, seq, correct);
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353 return !memcmp(correct, blk + len, 20);
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356 static void hmacsha1_96_genresult(void *handle, unsigned char *hmac)
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358 unsigned char full[20];
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359 hmacsha1_genresult(handle, full);
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360 memcpy(hmac, full, 12);
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363 static void sha1_96_generate(void *handle, unsigned char *blk, int len,
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366 unsigned char full[20];
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367 sha1_do_hmac(handle, blk, len, seq, full);
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368 memcpy(blk + len, full, 12);
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371 static int hmacsha1_96_verresult(void *handle, unsigned char const *hmac)
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373 unsigned char correct[20];
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374 hmacsha1_genresult(handle, correct);
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375 return !memcmp(correct, hmac, 12);
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378 static int sha1_96_verify(void *handle, unsigned char *blk, int len,
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381 unsigned char correct[20];
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382 sha1_do_hmac(handle, blk, len, seq, correct);
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383 return !memcmp(correct, blk + len, 12);
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386 void hmac_sha1_simple(void *key, int keylen, void *data, int datalen,
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387 unsigned char *output) {
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388 SHA_State states[2];
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389 unsigned char intermediate[20];
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391 sha1_key_internal(states, key, keylen);
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392 SHA_Bytes(&states[0], data, datalen);
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393 SHA_Final(&states[0], intermediate);
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395 SHA_Bytes(&states[1], intermediate, 20);
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396 SHA_Final(&states[1], output);
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399 const struct ssh_mac ssh_hmac_sha1 = {
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400 sha1_make_context, sha1_free_context, sha1_key,
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401 sha1_generate, sha1_verify,
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402 hmacsha1_start, hmacsha1_bytes, hmacsha1_genresult, hmacsha1_verresult,
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408 const struct ssh_mac ssh_hmac_sha1_96 = {
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409 sha1_make_context, sha1_free_context, sha1_key,
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410 sha1_96_generate, sha1_96_verify,
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411 hmacsha1_start, hmacsha1_bytes,
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412 hmacsha1_96_genresult, hmacsha1_96_verresult,
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418 const struct ssh_mac ssh_hmac_sha1_buggy = {
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419 sha1_make_context, sha1_free_context, sha1_key_buggy,
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420 sha1_generate, sha1_verify,
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421 hmacsha1_start, hmacsha1_bytes, hmacsha1_genresult, hmacsha1_verresult,
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424 "bug-compatible HMAC-SHA1"
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427 const struct ssh_mac ssh_hmac_sha1_96_buggy = {
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428 sha1_make_context, sha1_free_context, sha1_key_buggy,
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429 sha1_96_generate, sha1_96_verify,
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430 hmacsha1_start, hmacsha1_bytes,
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431 hmacsha1_96_genresult, hmacsha1_96_verresult,
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434 "bug-compatible HMAC-SHA1-96"
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