Line data Source code
1 : // SPDX-License-Identifier: BSD-2-Clause
2 : /*-
3 : * Copyright 2005,2007,2009 Colin Percival
4 : * All rights reserved.
5 : */
6 :
7 : #include <zebra.h>
8 : #include "sha256.h"
9 :
10 : #if !HAVE_DECL_BE32DEC
11 258080 : static inline uint32_t be32dec(const void *pp)
12 : {
13 258080 : const uint8_t *p = (uint8_t const *)pp;
14 :
15 258080 : return ((uint32_t)(p[3]) + ((uint32_t)(p[2]) << 8)
16 258080 : + ((uint32_t)(p[1]) << 16) + ((uint32_t)(p[0]) << 24));
17 : }
18 : #endif
19 :
20 : #if !HAVE_DECL_BE32ENC
21 93000 : static inline void be32enc(void *pp, uint32_t x)
22 : {
23 93000 : uint8_t *p = (uint8_t *)pp;
24 :
25 93000 : p[3] = x & 0xff;
26 93000 : p[2] = (x >> 8) & 0xff;
27 93000 : p[1] = (x >> 16) & 0xff;
28 93000 : p[0] = (x >> 24) & 0xff;
29 : }
30 : #endif
31 :
32 : /*
33 : * Encode a length len/4 vector of (uint32_t) into a length len vector of
34 : * (unsigned char) in big-endian form. Assumes len is a multiple of 4.
35 : */
36 18600 : static void be32enc_vect(unsigned char *dst, const uint32_t *src, size_t len)
37 : {
38 18600 : size_t i;
39 :
40 111600 : for (i = 0; i < len / 4; i++)
41 93000 : be32enc(dst + i * 4, src[i]);
42 18600 : }
43 :
44 : /*
45 : * Decode a big-endian length len vector of (unsigned char) into a length
46 : * len/4 vector of (uint32_t). Assumes len is a multiple of 4.
47 : */
48 16130 : static void be32dec_vect(uint32_t *dst, const unsigned char *src, size_t len)
49 : {
50 16130 : size_t i;
51 :
52 274210 : for (i = 0; i < len / 4; i++)
53 258080 : dst[i] = be32dec(src + i * 4);
54 16130 : }
55 :
56 : /* Elementary functions used by SHA256 */
57 : #define Ch(x, y, z) ((x & (y ^ z)) ^ z)
58 : #define Maj(x, y, z) ((x & (y | z)) | (y & z))
59 : #define SHR(x, n) (x >> n)
60 : #define ROTR(x, n) ((x >> n) | (x << (32 - n)))
61 : #define S0(x) (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22))
62 : #define S1(x) (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25))
63 : #define s0(x) (ROTR(x, 7) ^ ROTR(x, 18) ^ SHR(x, 3))
64 : #define s1(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHR(x, 10))
65 :
66 : /* SHA256 round function */
67 : #define RND(a, b, c, d, e, f, g, h, k) \
68 : t0 = h + S1(e) + Ch(e, f, g) + k; \
69 : t1 = S0(a) + Maj(a, b, c); \
70 : d += t0; \
71 : h = t0 + t1;
72 :
73 : /* Adjusted round function for rotating state */
74 : #define RNDr(S, W, i, k) \
75 : RND(S[(64 - i) % 8], S[(65 - i) % 8], S[(66 - i) % 8], \
76 : S[(67 - i) % 8], S[(68 - i) % 8], S[(69 - i) % 8], \
77 : S[(70 - i) % 8], S[(71 - i) % 8], W[i] + k)
78 :
79 : /*
80 : * SHA256 block compression function. The 256-bit state is transformed via
81 : * the 512-bit input block to produce a new state.
82 : */
83 16130 : static void SHA256_Transform(uint32_t *state, const unsigned char block[64])
84 : {
85 16130 : uint32_t W[64];
86 16130 : uint32_t S[8];
87 16130 : uint32_t t0, t1;
88 16130 : int i;
89 :
90 : /* 1. Prepare message schedule W. */
91 16130 : be32dec_vect(W, block, 64);
92 806500 : for (i = 16; i < 64; i++)
93 774240 : W[i] = s1(W[i - 2]) + W[i - 7] + s0(W[i - 15]) + W[i - 16];
94 :
95 : /* 2. Initialize working variables. */
96 16130 : memcpy(S, state, 32);
97 :
98 : /* 3. Mix. */
99 16130 : RNDr(S, W, 0, 0x428a2f98);
100 16130 : RNDr(S, W, 1, 0x71374491);
101 16130 : RNDr(S, W, 2, 0xb5c0fbcf);
102 16130 : RNDr(S, W, 3, 0xe9b5dba5);
103 16130 : RNDr(S, W, 4, 0x3956c25b);
104 16130 : RNDr(S, W, 5, 0x59f111f1);
105 16130 : RNDr(S, W, 6, 0x923f82a4);
106 16130 : RNDr(S, W, 7, 0xab1c5ed5);
107 16130 : RNDr(S, W, 8, 0xd807aa98);
108 16130 : RNDr(S, W, 9, 0x12835b01);
109 16130 : RNDr(S, W, 10, 0x243185be);
110 16130 : RNDr(S, W, 11, 0x550c7dc3);
111 16130 : RNDr(S, W, 12, 0x72be5d74);
112 16130 : RNDr(S, W, 13, 0x80deb1fe);
113 16130 : RNDr(S, W, 14, 0x9bdc06a7);
114 16130 : RNDr(S, W, 15, 0xc19bf174);
115 16130 : RNDr(S, W, 16, 0xe49b69c1);
116 16130 : RNDr(S, W, 17, 0xefbe4786);
117 16130 : RNDr(S, W, 18, 0x0fc19dc6);
118 16130 : RNDr(S, W, 19, 0x240ca1cc);
119 16130 : RNDr(S, W, 20, 0x2de92c6f);
120 16130 : RNDr(S, W, 21, 0x4a7484aa);
121 16130 : RNDr(S, W, 22, 0x5cb0a9dc);
122 16130 : RNDr(S, W, 23, 0x76f988da);
123 16130 : RNDr(S, W, 24, 0x983e5152);
124 16130 : RNDr(S, W, 25, 0xa831c66d);
125 16130 : RNDr(S, W, 26, 0xb00327c8);
126 16130 : RNDr(S, W, 27, 0xbf597fc7);
127 16130 : RNDr(S, W, 28, 0xc6e00bf3);
128 16130 : RNDr(S, W, 29, 0xd5a79147);
129 16130 : RNDr(S, W, 30, 0x06ca6351);
130 16130 : RNDr(S, W, 31, 0x14292967);
131 16130 : RNDr(S, W, 32, 0x27b70a85);
132 16130 : RNDr(S, W, 33, 0x2e1b2138);
133 16130 : RNDr(S, W, 34, 0x4d2c6dfc);
134 16130 : RNDr(S, W, 35, 0x53380d13);
135 16130 : RNDr(S, W, 36, 0x650a7354);
136 16130 : RNDr(S, W, 37, 0x766a0abb);
137 16130 : RNDr(S, W, 38, 0x81c2c92e);
138 16130 : RNDr(S, W, 39, 0x92722c85);
139 16130 : RNDr(S, W, 40, 0xa2bfe8a1);
140 16130 : RNDr(S, W, 41, 0xa81a664b);
141 16130 : RNDr(S, W, 42, 0xc24b8b70);
142 16130 : RNDr(S, W, 43, 0xc76c51a3);
143 16130 : RNDr(S, W, 44, 0xd192e819);
144 16130 : RNDr(S, W, 45, 0xd6990624);
145 16130 : RNDr(S, W, 46, 0xf40e3585);
146 16130 : RNDr(S, W, 47, 0x106aa070);
147 16130 : RNDr(S, W, 48, 0x19a4c116);
148 16130 : RNDr(S, W, 49, 0x1e376c08);
149 16130 : RNDr(S, W, 50, 0x2748774c);
150 16130 : RNDr(S, W, 51, 0x34b0bcb5);
151 16130 : RNDr(S, W, 52, 0x391c0cb3);
152 16130 : RNDr(S, W, 53, 0x4ed8aa4a);
153 16130 : RNDr(S, W, 54, 0x5b9cca4f);
154 16130 : RNDr(S, W, 55, 0x682e6ff3);
155 16130 : RNDr(S, W, 56, 0x748f82ee);
156 16130 : RNDr(S, W, 57, 0x78a5636f);
157 16130 : RNDr(S, W, 58, 0x84c87814);
158 16130 : RNDr(S, W, 59, 0x8cc70208);
159 16130 : RNDr(S, W, 60, 0x90befffa);
160 16130 : RNDr(S, W, 61, 0xa4506ceb);
161 16130 : RNDr(S, W, 62, 0xbef9a3f7);
162 16130 : RNDr(S, W, 63, 0xc67178f2);
163 :
164 : /* 4. Mix local working variables into global state */
165 145170 : for (i = 0; i < 8; i++)
166 129040 : state[i] += S[i];
167 :
168 : /* Clean the stack. */
169 16130 : explicit_bzero(W, 256);
170 16130 : explicit_bzero(S, 32);
171 16130 : explicit_bzero(&t0, sizeof(t0));
172 16130 : explicit_bzero(&t1, sizeof(t0));
173 16130 : }
174 :
175 : static unsigned char PAD[64] = {
176 : 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
177 : 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
178 : 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
179 :
180 : /* Add padding and terminating bit-count. */
181 9300 : static void SHA256_Pad(SHA256_CTX *ctx)
182 : {
183 9300 : unsigned char len[8];
184 9300 : uint32_t r, plen;
185 :
186 : /*
187 : * Convert length to a vector of bytes -- we do this now rather
188 : * than later because the length will change after we pad.
189 : */
190 9300 : be32enc_vect(len, ctx->count, 8);
191 :
192 : /* Add 1--64 bytes so that the resulting length is 56 mod 64 */
193 9300 : r = (ctx->count[1] >> 3) & 0x3f;
194 9300 : plen = (r < 56) ? (56 - r) : (120 - r);
195 9300 : SHA256_Update(ctx, PAD, (size_t)plen);
196 :
197 : /* Add the terminating bit-count */
198 9300 : SHA256_Update(ctx, len, 8);
199 9300 : }
200 :
201 : /* SHA-256 initialization. Begins a SHA-256 operation. */
202 9300 : void SHA256_Init(SHA256_CTX *ctx)
203 : {
204 :
205 : /* Zero bits processed so far */
206 9300 : ctx->count[0] = ctx->count[1] = 0;
207 :
208 : /* Magic initialization constants */
209 9300 : ctx->state[0] = 0x6A09E667;
210 9300 : ctx->state[1] = 0xBB67AE85;
211 9300 : ctx->state[2] = 0x3C6EF372;
212 9300 : ctx->state[3] = 0xA54FF53A;
213 9300 : ctx->state[4] = 0x510E527F;
214 9300 : ctx->state[5] = 0x9B05688C;
215 9300 : ctx->state[6] = 0x1F83D9AB;
216 9300 : ctx->state[7] = 0x5BE0CD19;
217 9300 : }
218 :
219 : /* Add bytes into the hash */
220 55800 : void SHA256_Update(SHA256_CTX *ctx, const void *in, size_t len)
221 : {
222 55800 : uint32_t bitlen[2];
223 55800 : uint32_t r;
224 55800 : const unsigned char *src = in;
225 :
226 : /* Number of bytes left in the buffer from previous updates */
227 55800 : r = (ctx->count[1] >> 3) & 0x3f;
228 :
229 : /* Convert the length into a number of bits */
230 55800 : bitlen[1] = ((uint32_t)len) << 3;
231 55800 : bitlen[0] = (uint32_t)(len >> 29);
232 :
233 : /* Update number of bits */
234 55800 : if ((ctx->count[1] += bitlen[1]) < bitlen[1])
235 0 : ctx->count[0]++;
236 55800 : ctx->count[0] += bitlen[0];
237 :
238 : /* Handle the case where we don't need to perform any transforms */
239 55800 : if (len < 64 - r) {
240 39722 : memcpy(&ctx->buf[r], src, len);
241 39722 : return;
242 : }
243 :
244 : /* Finish the current block */
245 16078 : memcpy(&ctx->buf[r], src, 64 - r);
246 16078 : SHA256_Transform(ctx->state, ctx->buf);
247 16078 : src += 64 - r;
248 16078 : len -= 64 - r;
249 :
250 : /* Perform complete blocks */
251 16130 : while (len >= 64) {
252 52 : SHA256_Transform(ctx->state, src);
253 52 : src += 64;
254 52 : len -= 64;
255 : }
256 :
257 : /* Copy left over data into buffer */
258 16078 : memcpy(ctx->buf, src, len);
259 : }
260 :
261 : /*
262 : * SHA-256 finalization. Pads the input data, exports the hash value,
263 : * and clears the context state.
264 : */
265 9300 : void SHA256_Final(unsigned char digest[32], SHA256_CTX *ctx)
266 : {
267 :
268 : /* Add padding */
269 9300 : SHA256_Pad(ctx);
270 :
271 : /* Write the hash */
272 9300 : be32enc_vect(digest, ctx->state, 32);
273 :
274 : /* Clear the context state */
275 9300 : explicit_bzero((void *)ctx, sizeof(*ctx));
276 9300 : }
277 :
278 : /* Initialize an HMAC-SHA256 operation with the given key. */
279 0 : void HMAC__SHA256_Init(HMAC_SHA256_CTX *ctx, const void *_K, size_t Klen)
280 : {
281 0 : unsigned char pad[64];
282 0 : unsigned char khash[32];
283 0 : const unsigned char *K = _K;
284 0 : size_t i;
285 :
286 : /* If Klen > 64, the key is really SHA256(K). */
287 0 : if (Klen > 64) {
288 0 : SHA256_Init(&ctx->ictx);
289 0 : SHA256_Update(&ctx->ictx, K, Klen);
290 0 : SHA256_Final(khash, &ctx->ictx);
291 0 : K = khash;
292 0 : Klen = 32;
293 : }
294 :
295 : /* Inner SHA256 operation is SHA256(K xor [block of 0x36] || data). */
296 0 : SHA256_Init(&ctx->ictx);
297 0 : memset(pad, 0x36, 64);
298 0 : for (i = 0; i < Klen; i++)
299 0 : pad[i] ^= K[i];
300 0 : SHA256_Update(&ctx->ictx, pad, 64);
301 :
302 : /* Outer SHA256 operation is SHA256(K xor [block of 0x5c] || hash). */
303 0 : SHA256_Init(&ctx->octx);
304 0 : memset(pad, 0x5c, 64);
305 0 : for (i = 0; i < Klen; i++)
306 0 : pad[i] ^= K[i];
307 0 : SHA256_Update(&ctx->octx, pad, 64);
308 :
309 : /* Clean the stack. */
310 0 : explicit_bzero(khash, 32);
311 0 : }
312 :
313 : /* Add bytes to the HMAC-SHA256 operation. */
314 0 : void HMAC__SHA256_Update(HMAC_SHA256_CTX *ctx, const void *in, size_t len)
315 : {
316 :
317 : /* Feed data to the inner SHA256 operation. */
318 0 : SHA256_Update(&ctx->ictx, in, len);
319 0 : }
320 :
321 : /* Finish an HMAC-SHA256 operation. */
322 0 : void HMAC__SHA256_Final(unsigned char digest[32], HMAC_SHA256_CTX *ctx)
323 : {
324 0 : unsigned char ihash[32];
325 :
326 : /* Finish the inner SHA256 operation. */
327 0 : SHA256_Final(ihash, &ctx->ictx);
328 :
329 : /* Feed the inner hash to the outer SHA256 operation. */
330 0 : SHA256_Update(&ctx->octx, ihash, 32);
331 :
332 : /* Finish the outer SHA256 operation. */
333 0 : SHA256_Final(digest, &ctx->octx);
334 :
335 : /* Clean the stack. */
336 0 : explicit_bzero(ihash, 32);
337 0 : }
338 :
339 : /**
340 : * PBKDF2_SHA256(passwd, passwdlen, salt, saltlen, c, buf, dkLen):
341 : * Compute PBKDF2(passwd, salt, c, dkLen) using HMAC-SHA256 as the PRF, and
342 : * write the output to buf. The value dkLen must be at most 32 * (2^32 - 1).
343 : */
344 0 : void PBKDF2_SHA256(const uint8_t *passwd, size_t passwdlen, const uint8_t *salt,
345 : size_t saltlen, uint64_t c, uint8_t *buf, size_t dkLen)
346 : {
347 0 : HMAC_SHA256_CTX PShctx = {}, hctx;
348 0 : size_t i;
349 0 : uint8_t ivec[4];
350 0 : uint8_t U[32];
351 0 : uint8_t T[32];
352 0 : uint64_t j;
353 0 : int k;
354 0 : size_t clen;
355 :
356 : /* Compute HMAC state after processing P and S. */
357 0 : HMAC__SHA256_Init(&PShctx, passwd, passwdlen);
358 0 : HMAC__SHA256_Update(&PShctx, salt, saltlen);
359 :
360 : /* Iterate through the blocks. */
361 0 : for (i = 0; i * 32 < dkLen; i++) {
362 : /* Generate INT(i + 1). */
363 0 : be32enc(ivec, (uint32_t)(i + 1));
364 :
365 : /* Compute U_1 = PRF(P, S || INT(i)). */
366 0 : memcpy(&hctx, &PShctx, sizeof(HMAC_SHA256_CTX));
367 0 : HMAC__SHA256_Update(&hctx, ivec, 4);
368 0 : HMAC__SHA256_Final(U, &hctx);
369 :
370 : /* T_i = U_1 ... */
371 0 : memcpy(T, U, 32);
372 :
373 0 : for (j = 2; j <= c; j++) {
374 : /* Compute U_j. */
375 0 : HMAC__SHA256_Init(&hctx, passwd, passwdlen);
376 0 : HMAC__SHA256_Update(&hctx, U, 32);
377 0 : HMAC__SHA256_Final(U, &hctx);
378 :
379 : /* ... xor U_j ... */
380 0 : for (k = 0; k < 32; k++)
381 0 : T[k] ^= U[k];
382 : }
383 :
384 : /* Copy as many bytes as necessary into buf. */
385 0 : clen = dkLen - i * 32;
386 0 : if (clen > 32)
387 : clen = 32;
388 0 : memcpy(&buf[i * 32], T, clen);
389 : }
390 :
391 : /* Clean PShctx, since we never called _Final on it. */
392 0 : explicit_bzero(&PShctx, sizeof(HMAC_SHA256_CTX));
393 0 : }
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