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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 | ||
4f13df62 | 30 | #ifdef GNU_LINUX |
7f57883e DS |
31 | static inline uint32_t |
32 | be32dec(const void *pp) | |
33 | { | |
34 | const uint8_t *p = (uint8_t const *)pp; | |
35 | ||
36 | return ((uint32_t)(p[3]) + ((uint32_t)(p[2]) << 8) + | |
37 | ((uint32_t)(p[1]) << 16) + ((uint32_t)(p[0]) << 24)); | |
38 | } | |
39 | ||
40 | static inline void | |
41 | be32enc(void *pp, uint32_t x) | |
42 | { | |
43 | uint8_t * p = (uint8_t *)pp; | |
44 | ||
45 | p[3] = x & 0xff; | |
46 | p[2] = (x >> 8) & 0xff; | |
47 | p[1] = (x >> 16) & 0xff; | |
48 | p[0] = (x >> 24) & 0xff; | |
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 | */ | |
56 | static void | |
57 | be32enc_vect(unsigned char *dst, const uint32_t *src, size_t len) | |
58 | { | |
59 | size_t i; | |
60 | ||
61 | for (i = 0; i < len / 4; i++) | |
62 | be32enc(dst + i * 4, src[i]); | |
63 | } | |
64 | ||
65 | /* | |
66 | * Decode a big-endian length len vector of (unsigned char) into a length | |
67 | * len/4 vector of (uint32_t). Assumes len is a multiple of 4. | |
68 | */ | |
69 | static void | |
70 | be32dec_vect(uint32_t *dst, const unsigned char *src, size_t len) | |
71 | { | |
72 | size_t i; | |
73 | ||
74 | for (i = 0; i < len / 4; i++) | |
75 | dst[i] = be32dec(src + i * 4); | |
76 | } | |
77 | ||
78 | /* Elementary functions used by SHA256 */ | |
79 | #define Ch(x, y, z) ((x & (y ^ z)) ^ z) | |
80 | #define Maj(x, y, z) ((x & (y | z)) | (y & z)) | |
81 | #define SHR(x, n) (x >> n) | |
82 | #define ROTR(x, n) ((x >> n) | (x << (32 - n))) | |
83 | #define S0(x) (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22)) | |
84 | #define S1(x) (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25)) | |
85 | #define s0(x) (ROTR(x, 7) ^ ROTR(x, 18) ^ SHR(x, 3)) | |
86 | #define s1(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHR(x, 10)) | |
87 | ||
88 | /* SHA256 round function */ | |
89 | #define RND(a, b, c, d, e, f, g, h, k) \ | |
90 | t0 = h + S1(e) + Ch(e, f, g) + k; \ | |
91 | t1 = S0(a) + Maj(a, b, c); \ | |
92 | d += t0; \ | |
93 | h = t0 + t1; | |
94 | ||
95 | /* Adjusted round function for rotating state */ | |
96 | #define RNDr(S, W, i, k) \ | |
97 | RND(S[(64 - i) % 8], S[(65 - i) % 8], \ | |
98 | S[(66 - i) % 8], S[(67 - i) % 8], \ | |
99 | S[(68 - i) % 8], S[(69 - i) % 8], \ | |
100 | S[(70 - i) % 8], S[(71 - i) % 8], \ | |
101 | W[i] + k) | |
102 | ||
103 | /* | |
104 | * SHA256 block compression function. The 256-bit state is transformed via | |
105 | * the 512-bit input block to produce a new state. | |
106 | */ | |
107 | static void | |
108 | SHA256_Transform(uint32_t * state, const unsigned char block[64]) | |
109 | { | |
110 | uint32_t W[64]; | |
111 | uint32_t S[8]; | |
112 | uint32_t t0, t1; | |
113 | int i; | |
114 | ||
115 | /* 1. Prepare message schedule W. */ | |
116 | be32dec_vect(W, block, 64); | |
117 | for (i = 16; i < 64; i++) | |
118 | W[i] = s1(W[i - 2]) + W[i - 7] + s0(W[i - 15]) + W[i - 16]; | |
119 | ||
120 | /* 2. Initialize working variables. */ | |
121 | memcpy(S, state, 32); | |
122 | ||
123 | /* 3. Mix. */ | |
124 | RNDr(S, W, 0, 0x428a2f98); | |
125 | RNDr(S, W, 1, 0x71374491); | |
126 | RNDr(S, W, 2, 0xb5c0fbcf); | |
127 | RNDr(S, W, 3, 0xe9b5dba5); | |
128 | RNDr(S, W, 4, 0x3956c25b); | |
129 | RNDr(S, W, 5, 0x59f111f1); | |
130 | RNDr(S, W, 6, 0x923f82a4); | |
131 | RNDr(S, W, 7, 0xab1c5ed5); | |
132 | RNDr(S, W, 8, 0xd807aa98); | |
133 | RNDr(S, W, 9, 0x12835b01); | |
134 | RNDr(S, W, 10, 0x243185be); | |
135 | RNDr(S, W, 11, 0x550c7dc3); | |
136 | RNDr(S, W, 12, 0x72be5d74); | |
137 | RNDr(S, W, 13, 0x80deb1fe); | |
138 | RNDr(S, W, 14, 0x9bdc06a7); | |
139 | RNDr(S, W, 15, 0xc19bf174); | |
140 | RNDr(S, W, 16, 0xe49b69c1); | |
141 | RNDr(S, W, 17, 0xefbe4786); | |
142 | RNDr(S, W, 18, 0x0fc19dc6); | |
143 | RNDr(S, W, 19, 0x240ca1cc); | |
144 | RNDr(S, W, 20, 0x2de92c6f); | |
145 | RNDr(S, W, 21, 0x4a7484aa); | |
146 | RNDr(S, W, 22, 0x5cb0a9dc); | |
147 | RNDr(S, W, 23, 0x76f988da); | |
148 | RNDr(S, W, 24, 0x983e5152); | |
149 | RNDr(S, W, 25, 0xa831c66d); | |
150 | RNDr(S, W, 26, 0xb00327c8); | |
151 | RNDr(S, W, 27, 0xbf597fc7); | |
152 | RNDr(S, W, 28, 0xc6e00bf3); | |
153 | RNDr(S, W, 29, 0xd5a79147); | |
154 | RNDr(S, W, 30, 0x06ca6351); | |
155 | RNDr(S, W, 31, 0x14292967); | |
156 | RNDr(S, W, 32, 0x27b70a85); | |
157 | RNDr(S, W, 33, 0x2e1b2138); | |
158 | RNDr(S, W, 34, 0x4d2c6dfc); | |
159 | RNDr(S, W, 35, 0x53380d13); | |
160 | RNDr(S, W, 36, 0x650a7354); | |
161 | RNDr(S, W, 37, 0x766a0abb); | |
162 | RNDr(S, W, 38, 0x81c2c92e); | |
163 | RNDr(S, W, 39, 0x92722c85); | |
164 | RNDr(S, W, 40, 0xa2bfe8a1); | |
165 | RNDr(S, W, 41, 0xa81a664b); | |
166 | RNDr(S, W, 42, 0xc24b8b70); | |
167 | RNDr(S, W, 43, 0xc76c51a3); | |
168 | RNDr(S, W, 44, 0xd192e819); | |
169 | RNDr(S, W, 45, 0xd6990624); | |
170 | RNDr(S, W, 46, 0xf40e3585); | |
171 | RNDr(S, W, 47, 0x106aa070); | |
172 | RNDr(S, W, 48, 0x19a4c116); | |
173 | RNDr(S, W, 49, 0x1e376c08); | |
174 | RNDr(S, W, 50, 0x2748774c); | |
175 | RNDr(S, W, 51, 0x34b0bcb5); | |
176 | RNDr(S, W, 52, 0x391c0cb3); | |
177 | RNDr(S, W, 53, 0x4ed8aa4a); | |
178 | RNDr(S, W, 54, 0x5b9cca4f); | |
179 | RNDr(S, W, 55, 0x682e6ff3); | |
180 | RNDr(S, W, 56, 0x748f82ee); | |
181 | RNDr(S, W, 57, 0x78a5636f); | |
182 | RNDr(S, W, 58, 0x84c87814); | |
183 | RNDr(S, W, 59, 0x8cc70208); | |
184 | RNDr(S, W, 60, 0x90befffa); | |
185 | RNDr(S, W, 61, 0xa4506ceb); | |
186 | RNDr(S, W, 62, 0xbef9a3f7); | |
187 | RNDr(S, W, 63, 0xc67178f2); | |
188 | ||
189 | /* 4. Mix local working variables into global state */ | |
190 | for (i = 0; i < 8; i++) | |
191 | state[i] += S[i]; | |
192 | ||
193 | /* Clean the stack. */ | |
194 | memset(W, 0, 256); | |
195 | memset(S, 0, 32); | |
196 | t0 = t1 = 0; | |
197 | } | |
198 | ||
199 | static unsigned char PAD[64] = { | |
200 | 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | |
201 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | |
202 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | |
203 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 | |
204 | }; | |
205 | ||
206 | /* Add padding and terminating bit-count. */ | |
207 | static void | |
208 | SHA256_Pad(SHA256_CTX * ctx) | |
209 | { | |
210 | unsigned char len[8]; | |
211 | uint32_t r, plen; | |
212 | ||
213 | /* | |
214 | * Convert length to a vector of bytes -- we do this now rather | |
215 | * than later because the length will change after we pad. | |
216 | */ | |
217 | be32enc_vect(len, ctx->count, 8); | |
218 | ||
219 | /* Add 1--64 bytes so that the resulting length is 56 mod 64 */ | |
220 | r = (ctx->count[1] >> 3) & 0x3f; | |
221 | plen = (r < 56) ? (56 - r) : (120 - r); | |
222 | SHA256_Update(ctx, PAD, (size_t)plen); | |
223 | ||
224 | /* Add the terminating bit-count */ | |
225 | SHA256_Update(ctx, len, 8); | |
226 | } | |
227 | ||
228 | /* SHA-256 initialization. Begins a SHA-256 operation. */ | |
229 | void | |
230 | SHA256_Init(SHA256_CTX * ctx) | |
231 | { | |
232 | ||
233 | /* Zero bits processed so far */ | |
234 | ctx->count[0] = ctx->count[1] = 0; | |
235 | ||
236 | /* Magic initialization constants */ | |
237 | ctx->state[0] = 0x6A09E667; | |
238 | ctx->state[1] = 0xBB67AE85; | |
239 | ctx->state[2] = 0x3C6EF372; | |
240 | ctx->state[3] = 0xA54FF53A; | |
241 | ctx->state[4] = 0x510E527F; | |
242 | ctx->state[5] = 0x9B05688C; | |
243 | ctx->state[6] = 0x1F83D9AB; | |
244 | ctx->state[7] = 0x5BE0CD19; | |
245 | } | |
246 | ||
247 | /* Add bytes into the hash */ | |
248 | void | |
249 | SHA256_Update(SHA256_CTX * ctx, const void *in, size_t len) | |
250 | { | |
251 | uint32_t bitlen[2]; | |
252 | uint32_t r; | |
253 | const unsigned char *src = in; | |
254 | ||
255 | /* Number of bytes left in the buffer from previous updates */ | |
256 | r = (ctx->count[1] >> 3) & 0x3f; | |
257 | ||
258 | /* Convert the length into a number of bits */ | |
259 | bitlen[1] = ((uint32_t)len) << 3; | |
260 | bitlen[0] = (uint32_t)(len >> 29); | |
261 | ||
262 | /* Update number of bits */ | |
263 | if ((ctx->count[1] += bitlen[1]) < bitlen[1]) | |
264 | ctx->count[0]++; | |
265 | ctx->count[0] += bitlen[0]; | |
266 | ||
267 | /* Handle the case where we don't need to perform any transforms */ | |
268 | if (len < 64 - r) { | |
269 | memcpy(&ctx->buf[r], src, len); | |
270 | return; | |
271 | } | |
272 | ||
273 | /* Finish the current block */ | |
274 | memcpy(&ctx->buf[r], src, 64 - r); | |
275 | SHA256_Transform(ctx->state, ctx->buf); | |
276 | src += 64 - r; | |
277 | len -= 64 - r; | |
278 | ||
279 | /* Perform complete blocks */ | |
280 | while (len >= 64) { | |
281 | SHA256_Transform(ctx->state, src); | |
282 | src += 64; | |
283 | len -= 64; | |
284 | } | |
285 | ||
286 | /* Copy left over data into buffer */ | |
287 | memcpy(ctx->buf, src, len); | |
288 | } | |
289 | ||
290 | /* | |
291 | * SHA-256 finalization. Pads the input data, exports the hash value, | |
292 | * and clears the context state. | |
293 | */ | |
294 | void | |
295 | SHA256_Final(unsigned char digest[32], SHA256_CTX * ctx) | |
296 | { | |
297 | ||
298 | /* Add padding */ | |
299 | SHA256_Pad(ctx); | |
300 | ||
301 | /* Write the hash */ | |
302 | be32enc_vect(digest, ctx->state, 32); | |
303 | ||
304 | /* Clear the context state */ | |
305 | memset((void *)ctx, 0, sizeof(*ctx)); | |
306 | } | |
307 | ||
308 | /* Initialize an HMAC-SHA256 operation with the given key. */ | |
309 | void | |
310 | HMAC__SHA256_Init(HMAC_SHA256_CTX * ctx, const void * _K, size_t Klen) | |
311 | { | |
312 | unsigned char pad[64]; | |
313 | unsigned char khash[32]; | |
314 | const unsigned char * K = _K; | |
315 | size_t i; | |
316 | ||
317 | /* If Klen > 64, the key is really SHA256(K). */ | |
318 | if (Klen > 64) { | |
319 | SHA256_Init(&ctx->ictx); | |
320 | SHA256_Update(&ctx->ictx, K, Klen); | |
321 | SHA256_Final(khash, &ctx->ictx); | |
322 | K = khash; | |
323 | Klen = 32; | |
324 | } | |
325 | ||
326 | /* Inner SHA256 operation is SHA256(K xor [block of 0x36] || data). */ | |
327 | SHA256_Init(&ctx->ictx); | |
328 | memset(pad, 0x36, 64); | |
329 | for (i = 0; i < Klen; i++) | |
330 | pad[i] ^= K[i]; | |
331 | SHA256_Update(&ctx->ictx, pad, 64); | |
332 | ||
333 | /* Outer SHA256 operation is SHA256(K xor [block of 0x5c] || hash). */ | |
334 | SHA256_Init(&ctx->octx); | |
335 | memset(pad, 0x5c, 64); | |
336 | for (i = 0; i < Klen; i++) | |
337 | pad[i] ^= K[i]; | |
338 | SHA256_Update(&ctx->octx, pad, 64); | |
339 | ||
340 | /* Clean the stack. */ | |
341 | memset(khash, 0, 32); | |
342 | } | |
343 | ||
344 | /* Add bytes to the HMAC-SHA256 operation. */ | |
345 | void | |
346 | HMAC__SHA256_Update(HMAC_SHA256_CTX * ctx, const void *in, size_t len) | |
347 | { | |
348 | ||
349 | /* Feed data to the inner SHA256 operation. */ | |
350 | SHA256_Update(&ctx->ictx, in, len); | |
351 | } | |
352 | ||
353 | /* Finish an HMAC-SHA256 operation. */ | |
354 | void | |
355 | HMAC__SHA256_Final(unsigned char digest[32], HMAC_SHA256_CTX * ctx) | |
356 | { | |
357 | unsigned char ihash[32]; | |
358 | ||
359 | /* Finish the inner SHA256 operation. */ | |
360 | SHA256_Final(ihash, &ctx->ictx); | |
361 | ||
362 | /* Feed the inner hash to the outer SHA256 operation. */ | |
363 | SHA256_Update(&ctx->octx, ihash, 32); | |
364 | ||
365 | /* Finish the outer SHA256 operation. */ | |
366 | SHA256_Final(digest, &ctx->octx); | |
367 | ||
368 | /* Clean the stack. */ | |
369 | memset(ihash, 0, 32); | |
370 | } | |
371 | ||
372 | /** | |
373 | * PBKDF2_SHA256(passwd, passwdlen, salt, saltlen, c, buf, dkLen): | |
374 | * Compute PBKDF2(passwd, salt, c, dkLen) using HMAC-SHA256 as the PRF, and | |
375 | * write the output to buf. The value dkLen must be at most 32 * (2^32 - 1). | |
376 | */ | |
377 | void | |
378 | PBKDF2_SHA256(const uint8_t * passwd, size_t passwdlen, const uint8_t * salt, | |
379 | size_t saltlen, uint64_t c, uint8_t * buf, size_t dkLen) | |
380 | { | |
381 | HMAC_SHA256_CTX PShctx, hctx; | |
382 | size_t i; | |
383 | uint8_t ivec[4]; | |
384 | uint8_t U[32]; | |
385 | uint8_t T[32]; | |
386 | uint64_t j; | |
387 | int k; | |
388 | size_t clen; | |
389 | ||
390 | /* Compute HMAC state after processing P and S. */ | |
391 | HMAC__SHA256_Init(&PShctx, passwd, passwdlen); | |
392 | HMAC__SHA256_Update(&PShctx, salt, saltlen); | |
393 | ||
394 | /* Iterate through the blocks. */ | |
395 | for (i = 0; i * 32 < dkLen; i++) { | |
396 | /* Generate INT(i + 1). */ | |
397 | be32enc(ivec, (uint32_t)(i + 1)); | |
398 | ||
399 | /* Compute U_1 = PRF(P, S || INT(i)). */ | |
400 | memcpy(&hctx, &PShctx, sizeof(HMAC_SHA256_CTX)); | |
401 | HMAC__SHA256_Update(&hctx, ivec, 4); | |
402 | HMAC__SHA256_Final(U, &hctx); | |
403 | ||
404 | /* T_i = U_1 ... */ | |
405 | memcpy(T, U, 32); | |
406 | ||
407 | for (j = 2; j <= c; j++) { | |
408 | /* Compute U_j. */ | |
409 | HMAC__SHA256_Init(&hctx, passwd, passwdlen); | |
410 | HMAC__SHA256_Update(&hctx, U, 32); | |
411 | HMAC__SHA256_Final(U, &hctx); | |
412 | ||
413 | /* ... xor U_j ... */ | |
414 | for (k = 0; k < 32; k++) | |
415 | T[k] ^= U[k]; | |
416 | } | |
417 | ||
418 | /* Copy as many bytes as necessary into buf. */ | |
419 | clen = dkLen - i * 32; | |
420 | if (clen > 32) | |
421 | clen = 32; | |
422 | memcpy(&buf[i * 32], T, clen); | |
423 | } | |
424 | ||
425 | /* Clean PShctx, since we never called _Final on it. */ | |
426 | memset(&PShctx, 0, sizeof(HMAC_SHA256_CTX)); | |
427 | } |