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1 | /*- |
2 | * Copyright 2005,2007,2009 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 | ||
27 | #include <zebra.h> | |
28 | #include "sha256.h" | |
29 | ||
ba0cb3fe | 30 | #if !HAVE_DECL_BE32DEC |
d62a17ae | 31 | static inline uint32_t be32dec(const void *pp) |
7f57883e | 32 | { |
d62a17ae | 33 | const uint8_t *p = (uint8_t const *)pp; |
7f57883e | 34 | |
d62a17ae | 35 | return ((uint32_t)(p[3]) + ((uint32_t)(p[2]) << 8) |
36 | + ((uint32_t)(p[1]) << 16) + ((uint32_t)(p[0]) << 24)); | |
7f57883e | 37 | } |
ba0cb3fe | 38 | #endif |
7f57883e | 39 | |
ba0cb3fe | 40 | #if !HAVE_DECL_BE32ENC |
d62a17ae | 41 | static inline void be32enc(void *pp, uint32_t x) |
7f57883e | 42 | { |
d62a17ae | 43 | uint8_t *p = (uint8_t *)pp; |
7f57883e | 44 | |
d62a17ae | 45 | p[3] = x & 0xff; |
46 | p[2] = (x >> 8) & 0xff; | |
47 | p[1] = (x >> 16) & 0xff; | |
48 | p[0] = (x >> 24) & 0xff; | |
7f57883e | 49 | } |
4f13df62 | 50 | #endif |
7f57883e DS |
51 | |
52 | /* | |
53 | * Encode a length len/4 vector of (uint32_t) into a length len vector of | |
54 | * (unsigned char) in big-endian form. Assumes len is a multiple of 4. | |
55 | */ | |
d62a17ae | 56 | static void be32enc_vect(unsigned char *dst, const uint32_t *src, size_t len) |
7f57883e | 57 | { |
d62a17ae | 58 | size_t i; |
7f57883e | 59 | |
d62a17ae | 60 | for (i = 0; i < len / 4; i++) |
61 | be32enc(dst + i * 4, src[i]); | |
7f57883e DS |
62 | } |
63 | ||
64 | /* | |
65 | * Decode a big-endian length len vector of (unsigned char) into a length | |
66 | * len/4 vector of (uint32_t). Assumes len is a multiple of 4. | |
67 | */ | |
d62a17ae | 68 | static void be32dec_vect(uint32_t *dst, const unsigned char *src, size_t len) |
7f57883e | 69 | { |
d62a17ae | 70 | size_t i; |
7f57883e | 71 | |
d62a17ae | 72 | for (i = 0; i < len / 4; i++) |
73 | dst[i] = be32dec(src + i * 4); | |
7f57883e DS |
74 | } |
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 */ | |
d62a17ae | 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; | |
7f57883e DS |
92 | |
93 | /* Adjusted round function for rotating state */ | |
d62a17ae | 94 | #define RNDr(S, W, i, k) \ |
95 | RND(S[(64 - i) % 8], S[(65 - i) % 8], S[(66 - i) % 8], \ | |
96 | S[(67 - i) % 8], S[(68 - i) % 8], S[(69 - i) % 8], \ | |
97 | S[(70 - i) % 8], S[(71 - i) % 8], W[i] + k) | |
7f57883e DS |
98 | |
99 | /* | |
100 | * SHA256 block compression function. The 256-bit state is transformed via | |
101 | * the 512-bit input block to produce a new state. | |
102 | */ | |
d62a17ae | 103 | static void SHA256_Transform(uint32_t *state, const unsigned char block[64]) |
7f57883e | 104 | { |
d62a17ae | 105 | uint32_t W[64]; |
106 | uint32_t S[8]; | |
107 | uint32_t t0, t1; | |
108 | int i; | |
109 | ||
110 | /* 1. Prepare message schedule W. */ | |
111 | be32dec_vect(W, block, 64); | |
112 | for (i = 16; i < 64; i++) | |
113 | W[i] = s1(W[i - 2]) + W[i - 7] + s0(W[i - 15]) + W[i - 16]; | |
114 | ||
115 | /* 2. Initialize working variables. */ | |
116 | memcpy(S, state, 32); | |
117 | ||
118 | /* 3. Mix. */ | |
119 | RNDr(S, W, 0, 0x428a2f98); | |
120 | RNDr(S, W, 1, 0x71374491); | |
121 | RNDr(S, W, 2, 0xb5c0fbcf); | |
122 | RNDr(S, W, 3, 0xe9b5dba5); | |
123 | RNDr(S, W, 4, 0x3956c25b); | |
124 | RNDr(S, W, 5, 0x59f111f1); | |
125 | RNDr(S, W, 6, 0x923f82a4); | |
126 | RNDr(S, W, 7, 0xab1c5ed5); | |
127 | RNDr(S, W, 8, 0xd807aa98); | |
128 | RNDr(S, W, 9, 0x12835b01); | |
129 | RNDr(S, W, 10, 0x243185be); | |
130 | RNDr(S, W, 11, 0x550c7dc3); | |
131 | RNDr(S, W, 12, 0x72be5d74); | |
132 | RNDr(S, W, 13, 0x80deb1fe); | |
133 | RNDr(S, W, 14, 0x9bdc06a7); | |
134 | RNDr(S, W, 15, 0xc19bf174); | |
135 | RNDr(S, W, 16, 0xe49b69c1); | |
136 | RNDr(S, W, 17, 0xefbe4786); | |
137 | RNDr(S, W, 18, 0x0fc19dc6); | |
138 | RNDr(S, W, 19, 0x240ca1cc); | |
139 | RNDr(S, W, 20, 0x2de92c6f); | |
140 | RNDr(S, W, 21, 0x4a7484aa); | |
141 | RNDr(S, W, 22, 0x5cb0a9dc); | |
142 | RNDr(S, W, 23, 0x76f988da); | |
143 | RNDr(S, W, 24, 0x983e5152); | |
144 | RNDr(S, W, 25, 0xa831c66d); | |
145 | RNDr(S, W, 26, 0xb00327c8); | |
146 | RNDr(S, W, 27, 0xbf597fc7); | |
147 | RNDr(S, W, 28, 0xc6e00bf3); | |
148 | RNDr(S, W, 29, 0xd5a79147); | |
149 | RNDr(S, W, 30, 0x06ca6351); | |
150 | RNDr(S, W, 31, 0x14292967); | |
151 | RNDr(S, W, 32, 0x27b70a85); | |
152 | RNDr(S, W, 33, 0x2e1b2138); | |
153 | RNDr(S, W, 34, 0x4d2c6dfc); | |
154 | RNDr(S, W, 35, 0x53380d13); | |
155 | RNDr(S, W, 36, 0x650a7354); | |
156 | RNDr(S, W, 37, 0x766a0abb); | |
157 | RNDr(S, W, 38, 0x81c2c92e); | |
158 | RNDr(S, W, 39, 0x92722c85); | |
159 | RNDr(S, W, 40, 0xa2bfe8a1); | |
160 | RNDr(S, W, 41, 0xa81a664b); | |
161 | RNDr(S, W, 42, 0xc24b8b70); | |
162 | RNDr(S, W, 43, 0xc76c51a3); | |
163 | RNDr(S, W, 44, 0xd192e819); | |
164 | RNDr(S, W, 45, 0xd6990624); | |
165 | RNDr(S, W, 46, 0xf40e3585); | |
166 | RNDr(S, W, 47, 0x106aa070); | |
167 | RNDr(S, W, 48, 0x19a4c116); | |
168 | RNDr(S, W, 49, 0x1e376c08); | |
169 | RNDr(S, W, 50, 0x2748774c); | |
170 | RNDr(S, W, 51, 0x34b0bcb5); | |
171 | RNDr(S, W, 52, 0x391c0cb3); | |
172 | RNDr(S, W, 53, 0x4ed8aa4a); | |
173 | RNDr(S, W, 54, 0x5b9cca4f); | |
174 | RNDr(S, W, 55, 0x682e6ff3); | |
175 | RNDr(S, W, 56, 0x748f82ee); | |
176 | RNDr(S, W, 57, 0x78a5636f); | |
177 | RNDr(S, W, 58, 0x84c87814); | |
178 | RNDr(S, W, 59, 0x8cc70208); | |
179 | RNDr(S, W, 60, 0x90befffa); | |
180 | RNDr(S, W, 61, 0xa4506ceb); | |
181 | RNDr(S, W, 62, 0xbef9a3f7); | |
182 | RNDr(S, W, 63, 0xc67178f2); | |
183 | ||
184 | /* 4. Mix local working variables into global state */ | |
185 | for (i = 0; i < 8; i++) | |
186 | state[i] += S[i]; | |
187 | ||
188 | /* Clean the stack. */ | |
189 | memset(W, 0, 256); | |
190 | memset(S, 0, 32); | |
7faf667a DS |
191 | memset(&t0, 0, sizeof(t0)); |
192 | memset(&t1, 0, sizeof(t0)); | |
7f57883e DS |
193 | } |
194 | ||
195 | static unsigned char PAD[64] = { | |
d62a17ae | 196 | 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
197 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | |
198 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}; | |
7f57883e DS |
199 | |
200 | /* Add padding and terminating bit-count. */ | |
d62a17ae | 201 | static void SHA256_Pad(SHA256_CTX *ctx) |
7f57883e | 202 | { |
d62a17ae | 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); | |
7f57883e DS |
219 | } |
220 | ||
221 | /* SHA-256 initialization. Begins a SHA-256 operation. */ | |
d62a17ae | 222 | void SHA256_Init(SHA256_CTX *ctx) |
7f57883e DS |
223 | { |
224 | ||
d62a17ae | 225 | /* Zero bits processed so far */ |
226 | ctx->count[0] = ctx->count[1] = 0; | |
227 | ||
228 | /* Magic initialization constants */ | |
229 | ctx->state[0] = 0x6A09E667; | |
230 | ctx->state[1] = 0xBB67AE85; | |
231 | ctx->state[2] = 0x3C6EF372; | |
232 | ctx->state[3] = 0xA54FF53A; | |
233 | ctx->state[4] = 0x510E527F; | |
234 | ctx->state[5] = 0x9B05688C; | |
235 | ctx->state[6] = 0x1F83D9AB; | |
236 | ctx->state[7] = 0x5BE0CD19; | |
7f57883e DS |
237 | } |
238 | ||
239 | /* Add bytes into the hash */ | |
d62a17ae | 240 | void SHA256_Update(SHA256_CTX *ctx, const void *in, size_t len) |
7f57883e | 241 | { |
d62a17ae | 242 | uint32_t bitlen[2]; |
243 | uint32_t r; | |
244 | const unsigned char *src = in; | |
245 | ||
246 | /* Number of bytes left in the buffer from previous updates */ | |
247 | r = (ctx->count[1] >> 3) & 0x3f; | |
248 | ||
249 | /* Convert the length into a number of bits */ | |
250 | bitlen[1] = ((uint32_t)len) << 3; | |
251 | bitlen[0] = (uint32_t)(len >> 29); | |
252 | ||
253 | /* Update number of bits */ | |
254 | if ((ctx->count[1] += bitlen[1]) < bitlen[1]) | |
255 | ctx->count[0]++; | |
256 | ctx->count[0] += bitlen[0]; | |
257 | ||
258 | /* Handle the case where we don't need to perform any transforms */ | |
259 | if (len < 64 - r) { | |
260 | memcpy(&ctx->buf[r], src, len); | |
261 | return; | |
262 | } | |
263 | ||
264 | /* Finish the current block */ | |
265 | memcpy(&ctx->buf[r], src, 64 - r); | |
266 | SHA256_Transform(ctx->state, ctx->buf); | |
267 | src += 64 - r; | |
268 | len -= 64 - r; | |
269 | ||
270 | /* Perform complete blocks */ | |
271 | while (len >= 64) { | |
272 | SHA256_Transform(ctx->state, src); | |
273 | src += 64; | |
274 | len -= 64; | |
275 | } | |
276 | ||
277 | /* Copy left over data into buffer */ | |
278 | memcpy(ctx->buf, src, len); | |
7f57883e DS |
279 | } |
280 | ||
281 | /* | |
282 | * SHA-256 finalization. Pads the input data, exports the hash value, | |
283 | * and clears the context state. | |
284 | */ | |
d62a17ae | 285 | void SHA256_Final(unsigned char digest[32], SHA256_CTX *ctx) |
7f57883e DS |
286 | { |
287 | ||
d62a17ae | 288 | /* Add padding */ |
289 | SHA256_Pad(ctx); | |
7f57883e | 290 | |
d62a17ae | 291 | /* Write the hash */ |
292 | be32enc_vect(digest, ctx->state, 32); | |
7f57883e | 293 | |
d62a17ae | 294 | /* Clear the context state */ |
295 | memset((void *)ctx, 0, sizeof(*ctx)); | |
7f57883e DS |
296 | } |
297 | ||
298 | /* Initialize an HMAC-SHA256 operation with the given key. */ | |
d62a17ae | 299 | void HMAC__SHA256_Init(HMAC_SHA256_CTX *ctx, const void *_K, size_t Klen) |
7f57883e | 300 | { |
d62a17ae | 301 | unsigned char pad[64]; |
302 | unsigned char khash[32]; | |
303 | const unsigned char *K = _K; | |
304 | size_t i; | |
305 | ||
306 | /* If Klen > 64, the key is really SHA256(K). */ | |
307 | if (Klen > 64) { | |
308 | SHA256_Init(&ctx->ictx); | |
309 | SHA256_Update(&ctx->ictx, K, Klen); | |
310 | SHA256_Final(khash, &ctx->ictx); | |
311 | K = khash; | |
312 | Klen = 32; | |
313 | } | |
314 | ||
315 | /* Inner SHA256 operation is SHA256(K xor [block of 0x36] || data). */ | |
316 | SHA256_Init(&ctx->ictx); | |
317 | memset(pad, 0x36, 64); | |
318 | for (i = 0; i < Klen; i++) | |
319 | pad[i] ^= K[i]; | |
320 | SHA256_Update(&ctx->ictx, pad, 64); | |
321 | ||
322 | /* Outer SHA256 operation is SHA256(K xor [block of 0x5c] || hash). */ | |
323 | SHA256_Init(&ctx->octx); | |
324 | memset(pad, 0x5c, 64); | |
325 | for (i = 0; i < Klen; i++) | |
326 | pad[i] ^= K[i]; | |
327 | SHA256_Update(&ctx->octx, pad, 64); | |
328 | ||
329 | /* Clean the stack. */ | |
330 | memset(khash, 0, 32); | |
7f57883e DS |
331 | } |
332 | ||
333 | /* Add bytes to the HMAC-SHA256 operation. */ | |
d62a17ae | 334 | void HMAC__SHA256_Update(HMAC_SHA256_CTX *ctx, const void *in, size_t len) |
7f57883e DS |
335 | { |
336 | ||
d62a17ae | 337 | /* Feed data to the inner SHA256 operation. */ |
338 | SHA256_Update(&ctx->ictx, in, len); | |
7f57883e DS |
339 | } |
340 | ||
341 | /* Finish an HMAC-SHA256 operation. */ | |
d62a17ae | 342 | void HMAC__SHA256_Final(unsigned char digest[32], HMAC_SHA256_CTX *ctx) |
7f57883e | 343 | { |
d62a17ae | 344 | unsigned char ihash[32]; |
7f57883e | 345 | |
d62a17ae | 346 | /* Finish the inner SHA256 operation. */ |
347 | SHA256_Final(ihash, &ctx->ictx); | |
7f57883e | 348 | |
d62a17ae | 349 | /* Feed the inner hash to the outer SHA256 operation. */ |
350 | SHA256_Update(&ctx->octx, ihash, 32); | |
7f57883e | 351 | |
d62a17ae | 352 | /* Finish the outer SHA256 operation. */ |
353 | SHA256_Final(digest, &ctx->octx); | |
7f57883e | 354 | |
d62a17ae | 355 | /* Clean the stack. */ |
356 | memset(ihash, 0, 32); | |
7f57883e DS |
357 | } |
358 | ||
359 | /** | |
360 | * PBKDF2_SHA256(passwd, passwdlen, salt, saltlen, c, buf, dkLen): | |
361 | * Compute PBKDF2(passwd, salt, c, dkLen) using HMAC-SHA256 as the PRF, and | |
362 | * write the output to buf. The value dkLen must be at most 32 * (2^32 - 1). | |
363 | */ | |
d62a17ae | 364 | void PBKDF2_SHA256(const uint8_t *passwd, size_t passwdlen, const uint8_t *salt, |
365 | size_t saltlen, uint64_t c, uint8_t *buf, size_t dkLen) | |
7f57883e | 366 | { |
d62a17ae | 367 | HMAC_SHA256_CTX PShctx, hctx; |
368 | size_t i; | |
369 | uint8_t ivec[4]; | |
370 | uint8_t U[32]; | |
371 | uint8_t T[32]; | |
372 | uint64_t j; | |
373 | int k; | |
374 | size_t clen; | |
375 | ||
376 | /* Compute HMAC state after processing P and S. */ | |
377 | HMAC__SHA256_Init(&PShctx, passwd, passwdlen); | |
378 | HMAC__SHA256_Update(&PShctx, salt, saltlen); | |
379 | ||
380 | /* Iterate through the blocks. */ | |
381 | for (i = 0; i * 32 < dkLen; i++) { | |
382 | /* Generate INT(i + 1). */ | |
383 | be32enc(ivec, (uint32_t)(i + 1)); | |
384 | ||
385 | /* Compute U_1 = PRF(P, S || INT(i)). */ | |
386 | memcpy(&hctx, &PShctx, sizeof(HMAC_SHA256_CTX)); | |
387 | HMAC__SHA256_Update(&hctx, ivec, 4); | |
388 | HMAC__SHA256_Final(U, &hctx); | |
389 | ||
390 | /* T_i = U_1 ... */ | |
391 | memcpy(T, U, 32); | |
392 | ||
393 | for (j = 2; j <= c; j++) { | |
394 | /* Compute U_j. */ | |
395 | HMAC__SHA256_Init(&hctx, passwd, passwdlen); | |
396 | HMAC__SHA256_Update(&hctx, U, 32); | |
397 | HMAC__SHA256_Final(U, &hctx); | |
398 | ||
399 | /* ... xor U_j ... */ | |
400 | for (k = 0; k < 32; k++) | |
401 | T[k] ^= U[k]; | |
402 | } | |
403 | ||
404 | /* Copy as many bytes as necessary into buf. */ | |
405 | clen = dkLen - i * 32; | |
406 | if (clen > 32) | |
407 | clen = 32; | |
408 | memcpy(&buf[i * 32], T, clen); | |
409 | } | |
410 | ||
411 | /* Clean PShctx, since we never called _Final on it. */ | |
412 | memset(&PShctx, 0, sizeof(HMAC_SHA256_CTX)); | |
7f57883e | 413 | } |