1 /*-
2 * Copyright 2005 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 <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29
30 #include <sys/endian.h>
31 #include <sys/types.h>
32
33 #include <string.h>
34
35 #include "sha256.h"
36
37 #if BYTE_ORDER == BIG_ENDIAN
38
39 /* Copy a vector of big-endian uint32_t into a vector of bytes */
40 #define be32enc_vect(dst, src, len) \
41 memcpy((void *)dst, (const void *)src, (size_t)len)
42
43 /* Copy a vector of bytes into a vector of big-endian uint32_t */
44 #define be32dec_vect(dst, src, len) \
45 memcpy((void *)dst, (const void *)src, (size_t)len)
46
47 #else /* BYTE_ORDER != BIG_ENDIAN */
48
49 /*
50 * Encode a length len/4 vector of (uint32_t) into a length len vector of
51 * (unsigned char) in big-endian form. Assumes len is a multiple of 4.
52 */
53 static void
be32enc_vect(unsigned char * dst,const uint32_t * src,size_t len)54 be32enc_vect(unsigned char *dst, const uint32_t *src, size_t len)
55 {
56 size_t i;
57
58 for (i = 0; i < len / 4; i++)
59 be32enc(dst + i * 4, src[i]);
60 }
61
62 /*
63 * Decode a big-endian length len vector of (unsigned char) into a length
64 * len/4 vector of (uint32_t). Assumes len is a multiple of 4.
65 */
66 static void
be32dec_vect(uint32_t * dst,const unsigned char * src,size_t len)67 be32dec_vect(uint32_t *dst, const unsigned char *src, size_t len)
68 {
69 size_t i;
70
71 for (i = 0; i < len / 4; i++)
72 dst[i] = be32dec(src + i * 4);
73 }
74
75 #endif /* BYTE_ORDER != BIG_ENDIAN */
76
77 /* Elementary functions used by SHA256 */
78 #define Ch(x, y, z) ((x & (y ^ z)) ^ z)
79 #define Maj(x, y, z) ((x & (y | z)) | (y & z))
80 #define SHR(x, n) (x >> n)
81 #define ROTR(x, n) ((x >> n) | (x << (32 - n)))
82 #define S0(x) (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22))
83 #define S1(x) (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25))
84 #define s0(x) (ROTR(x, 7) ^ ROTR(x, 18) ^ SHR(x, 3))
85 #define s1(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHR(x, 10))
86
87 /* SHA256 round function */
88 #define RND(a, b, c, d, e, f, g, h, k) \
89 t0 = h + S1(e) + Ch(e, f, g) + k; \
90 t1 = S0(a) + Maj(a, b, c); \
91 d += t0; \
92 h = t0 + t1;
93
94 /* Adjusted round function for rotating state */
95 #define RNDr(S, W, i, k) \
96 RND(S[(64 - i) % 8], S[(65 - i) % 8], \
97 S[(66 - i) % 8], S[(67 - i) % 8], \
98 S[(68 - i) % 8], S[(69 - i) % 8], \
99 S[(70 - i) % 8], S[(71 - i) % 8], \
100 W[i] + k)
101
102 /*
103 * SHA256 block compression function. The 256-bit state is transformed via
104 * the 512-bit input block to produce a new state.
105 */
106 static void
SHA256_Transform(uint32_t * state,const unsigned char block[64])107 SHA256_Transform(uint32_t * state, const unsigned char block[64])
108 {
109 uint32_t W[64];
110 uint32_t S[8];
111 uint32_t t0, t1;
112 int i;
113
114 /* 1. Prepare message schedule W. */
115 be32dec_vect(W, block, 64);
116 for (i = 16; i < 64; i++)
117 W[i] = s1(W[i - 2]) + W[i - 7] + s0(W[i - 15]) + W[i - 16];
118
119 /* 2. Initialize working variables. */
120 memcpy(S, state, 32);
121
122 /* 3. Mix. */
123 RNDr(S, W, 0, 0x428a2f98);
124 RNDr(S, W, 1, 0x71374491);
125 RNDr(S, W, 2, 0xb5c0fbcf);
126 RNDr(S, W, 3, 0xe9b5dba5);
127 RNDr(S, W, 4, 0x3956c25b);
128 RNDr(S, W, 5, 0x59f111f1);
129 RNDr(S, W, 6, 0x923f82a4);
130 RNDr(S, W, 7, 0xab1c5ed5);
131 RNDr(S, W, 8, 0xd807aa98);
132 RNDr(S, W, 9, 0x12835b01);
133 RNDr(S, W, 10, 0x243185be);
134 RNDr(S, W, 11, 0x550c7dc3);
135 RNDr(S, W, 12, 0x72be5d74);
136 RNDr(S, W, 13, 0x80deb1fe);
137 RNDr(S, W, 14, 0x9bdc06a7);
138 RNDr(S, W, 15, 0xc19bf174);
139 RNDr(S, W, 16, 0xe49b69c1);
140 RNDr(S, W, 17, 0xefbe4786);
141 RNDr(S, W, 18, 0x0fc19dc6);
142 RNDr(S, W, 19, 0x240ca1cc);
143 RNDr(S, W, 20, 0x2de92c6f);
144 RNDr(S, W, 21, 0x4a7484aa);
145 RNDr(S, W, 22, 0x5cb0a9dc);
146 RNDr(S, W, 23, 0x76f988da);
147 RNDr(S, W, 24, 0x983e5152);
148 RNDr(S, W, 25, 0xa831c66d);
149 RNDr(S, W, 26, 0xb00327c8);
150 RNDr(S, W, 27, 0xbf597fc7);
151 RNDr(S, W, 28, 0xc6e00bf3);
152 RNDr(S, W, 29, 0xd5a79147);
153 RNDr(S, W, 30, 0x06ca6351);
154 RNDr(S, W, 31, 0x14292967);
155 RNDr(S, W, 32, 0x27b70a85);
156 RNDr(S, W, 33, 0x2e1b2138);
157 RNDr(S, W, 34, 0x4d2c6dfc);
158 RNDr(S, W, 35, 0x53380d13);
159 RNDr(S, W, 36, 0x650a7354);
160 RNDr(S, W, 37, 0x766a0abb);
161 RNDr(S, W, 38, 0x81c2c92e);
162 RNDr(S, W, 39, 0x92722c85);
163 RNDr(S, W, 40, 0xa2bfe8a1);
164 RNDr(S, W, 41, 0xa81a664b);
165 RNDr(S, W, 42, 0xc24b8b70);
166 RNDr(S, W, 43, 0xc76c51a3);
167 RNDr(S, W, 44, 0xd192e819);
168 RNDr(S, W, 45, 0xd6990624);
169 RNDr(S, W, 46, 0xf40e3585);
170 RNDr(S, W, 47, 0x106aa070);
171 RNDr(S, W, 48, 0x19a4c116);
172 RNDr(S, W, 49, 0x1e376c08);
173 RNDr(S, W, 50, 0x2748774c);
174 RNDr(S, W, 51, 0x34b0bcb5);
175 RNDr(S, W, 52, 0x391c0cb3);
176 RNDr(S, W, 53, 0x4ed8aa4a);
177 RNDr(S, W, 54, 0x5b9cca4f);
178 RNDr(S, W, 55, 0x682e6ff3);
179 RNDr(S, W, 56, 0x748f82ee);
180 RNDr(S, W, 57, 0x78a5636f);
181 RNDr(S, W, 58, 0x84c87814);
182 RNDr(S, W, 59, 0x8cc70208);
183 RNDr(S, W, 60, 0x90befffa);
184 RNDr(S, W, 61, 0xa4506ceb);
185 RNDr(S, W, 62, 0xbef9a3f7);
186 RNDr(S, W, 63, 0xc67178f2);
187
188 /* 4. Mix local working variables into global state */
189 for (i = 0; i < 8; i++)
190 state[i] += S[i];
191 }
192
193 static unsigned char PAD[64] = {
194 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
195 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
196 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
198 };
199
200 /* Add padding and terminating bit-count. */
201 static void
SHA256_Pad(SHA256_CTX * ctx)202 SHA256_Pad(SHA256_CTX * ctx)
203 {
204 unsigned char len[8];
205 uint32_t r, plen;
206
207 /*
208 * Convert length to a vector of bytes -- we do this now rather
209 * than later because the length will change after we pad.
210 */
211 be32enc_vect(len, ctx->count, 8);
212
213 /* Add 1--64 bytes so that the resulting length is 56 mod 64 */
214 r = (ctx->count[1] >> 3) & 0x3f;
215 plen = (r < 56) ? (56 - r) : (120 - r);
216 SHA256_Update(ctx, PAD, (size_t)plen);
217
218 /* Add the terminating bit-count */
219 SHA256_Update(ctx, len, 8);
220 }
221
222 /* SHA-256 initialization. Begins a SHA-256 operation. */
223 void
SHA256_Init(SHA256_CTX * ctx)224 SHA256_Init(SHA256_CTX * ctx)
225 {
226
227 /* Zero bits processed so far */
228 ctx->count[0] = ctx->count[1] = 0;
229
230 /* Magic initialization constants */
231 ctx->state[0] = 0x6A09E667;
232 ctx->state[1] = 0xBB67AE85;
233 ctx->state[2] = 0x3C6EF372;
234 ctx->state[3] = 0xA54FF53A;
235 ctx->state[4] = 0x510E527F;
236 ctx->state[5] = 0x9B05688C;
237 ctx->state[6] = 0x1F83D9AB;
238 ctx->state[7] = 0x5BE0CD19;
239 }
240
241 /* Add bytes into the hash */
242 void
SHA256_Update(SHA256_CTX * ctx,const void * in,size_t len)243 SHA256_Update(SHA256_CTX * ctx, const void *in, size_t len)
244 {
245 uint32_t bitlen[2];
246 uint32_t r;
247 const unsigned char *src = in;
248
249 /* Number of bytes left in the buffer from previous updates */
250 r = (ctx->count[1] >> 3) & 0x3f;
251
252 /* Convert the length into a number of bits */
253 bitlen[1] = ((uint32_t)len) << 3;
254 bitlen[0] = (uint32_t)(len >> 29);
255
256 /* Update number of bits */
257 if ((ctx->count[1] += bitlen[1]) < bitlen[1])
258 ctx->count[0]++;
259 ctx->count[0] += bitlen[0];
260
261 /* Handle the case where we don't need to perform any transforms */
262 if (len < 64 - r) {
263 memcpy(&ctx->buf[r], src, len);
264 return;
265 }
266
267 /* Finish the current block */
268 memcpy(&ctx->buf[r], src, 64 - r);
269 SHA256_Transform(ctx->state, ctx->buf);
270 src += 64 - r;
271 len -= 64 - r;
272
273 /* Perform complete blocks */
274 while (len >= 64) {
275 SHA256_Transform(ctx->state, src);
276 src += 64;
277 len -= 64;
278 }
279
280 /* Copy left over data into buffer */
281 memcpy(ctx->buf, src, len);
282 }
283
284 /*
285 * SHA-256 finalization. Pads the input data, exports the hash value,
286 * and clears the context state.
287 */
288 void
SHA256_Final(unsigned char digest[32],SHA256_CTX * ctx)289 SHA256_Final(unsigned char digest[32], SHA256_CTX * ctx)
290 {
291
292 /* Add padding */
293 SHA256_Pad(ctx);
294
295 /* Write the hash */
296 be32enc_vect(digest, ctx->state, 32);
297
298 /* Clear the context state */
299 memset((void *)ctx, 0, sizeof(*ctx));
300 }
301