1 // SPDX-License-Identifier: Unlicense
2 /*
3 * sha256.c --- The sha256 algorithm
4 *
5 * (copied from LibTomCrypt with adaption.)
6 */
7 #include "sha256.h"
8 #include <string.h>
9
10 /* This is based on SHA256 implementation in LibTomCrypt that was released into
11 * public domain by Tom St Denis. */
12 /* the K array */
13 static const unsigned long K[64] = {
14 0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL, 0x3956c25bUL,
15 0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL, 0xd807aa98UL, 0x12835b01UL,
16 0x243185beUL, 0x550c7dc3UL, 0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL,
17 0xc19bf174UL, 0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
18 0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL, 0x983e5152UL,
19 0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL, 0xc6e00bf3UL, 0xd5a79147UL,
20 0x06ca6351UL, 0x14292967UL, 0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL,
21 0x53380d13UL, 0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
22 0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL, 0xd192e819UL,
23 0xd6990624UL, 0xf40e3585UL, 0x106aa070UL, 0x19a4c116UL, 0x1e376c08UL,
24 0x2748774cUL, 0x34b0bcb5UL, 0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL,
25 0x682e6ff3UL, 0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
26 0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL
27 };
28 /* Various logical functions */
29 #define RORc(x, y) \
30 ( ((((unsigned long) (x) & 0xFFFFFFFFUL) >> (unsigned long) ((y) & 31)) | \
31 ((unsigned long) (x) << (unsigned long) (32 - ((y) & 31)))) & 0xFFFFFFFFUL)
32 #define Ch(x,y,z) (z ^ (x & (y ^ z)))
33 #define Maj(x,y,z) (((x | y) & z) | (x & y))
34 #define S(x, n) RORc((x), (n))
35 #define R(x, n) (((x)&0xFFFFFFFFUL)>>(n))
36 #define Sigma0(x) (S(x, 2) ^ S(x, 13) ^ S(x, 22))
37 #define Sigma1(x) (S(x, 6) ^ S(x, 11) ^ S(x, 25))
38 #define Gamma0(x) (S(x, 7) ^ S(x, 18) ^ R(x, 3))
39 #define Gamma1(x) (S(x, 17) ^ S(x, 19) ^ R(x, 10))
40 #ifndef MIN
41 #define MIN(x, y) (((x) < (y)) ? (x) : (y))
42 #endif
43
44 #define STORE64H(x, y) \
45 do { \
46 (y)[0] = (unsigned char)(((x)>>56)&255);\
47 (y)[1] = (unsigned char)(((x)>>48)&255);\
48 (y)[2] = (unsigned char)(((x)>>40)&255);\
49 (y)[3] = (unsigned char)(((x)>>32)&255);\
50 (y)[4] = (unsigned char)(((x)>>24)&255);\
51 (y)[5] = (unsigned char)(((x)>>16)&255);\
52 (y)[6] = (unsigned char)(((x)>>8)&255);\
53 (y)[7] = (unsigned char)((x)&255); } while(0)
54
55 #define STORE32H(x, y) \
56 do { (y)[0] = (unsigned char)(((x)>>24)&255); (y)[1] = (unsigned char)(((x)>>16)&255); \
57 (y)[2] = (unsigned char)(((x)>>8)&255); (y)[3] = (unsigned char)((x)&255); } while(0)
58
59 #define LOAD32H(x, y) \
60 do { x = ((u32)((y)[0] & 255)<<24) | \
61 ((u32)((y)[1] & 255)<<16) | \
62 ((u32)((y)[2] & 255)<<8) | \
63 ((u32)((y)[3] & 255)); } while(0)
64
65 /* compress 512-bits */
sha256_compress(struct sha256_state * md,unsigned char * buf)66 static int sha256_compress(struct sha256_state *md, unsigned char *buf)
67 {
68 u32 S[8], W[64], t0, t1;
69 u32 t;
70 int i;
71 /* copy state into S */
72 for (i = 0; i < 8; i++) {
73 S[i] = md->state[i];
74 }
75 /* copy the state into 512-bits into W[0..15] */
76 for (i = 0; i < 16; i++)
77 LOAD32H(W[i], buf + (4 * i));
78 /* fill W[16..63] */
79 for (i = 16; i < 64; i++) {
80 W[i] = Gamma1(W[i - 2]) + W[i - 7] + Gamma0(W[i - 15]) +
81 W[i - 16];
82 }
83 /* Compress */
84 #define RND(a,b,c,d,e,f,g,h,i) \
85 t0 = h + Sigma1(e) + Ch(e, f, g) + K[i] + W[i]; \
86 t1 = Sigma0(a) + Maj(a, b, c); \
87 d += t0; \
88 h = t0 + t1;
89 for (i = 0; i < 64; ++i) {
90 RND(S[0], S[1], S[2], S[3], S[4], S[5], S[6], S[7], i);
91 t = S[7]; S[7] = S[6]; S[6] = S[5]; S[5] = S[4];
92 S[4] = S[3]; S[3] = S[2]; S[2] = S[1]; S[1] = S[0]; S[0] = t;
93 }
94 /* feedback */
95 for (i = 0; i < 8; i++) {
96 md->state[i] = md->state[i] + S[i];
97 }
98 return 0;
99 }
100 /* Initialize the hash state */
erofs_sha256_init(struct sha256_state * md)101 void erofs_sha256_init(struct sha256_state *md)
102 {
103 md->curlen = 0;
104 md->length = 0;
105 md->state[0] = 0x6A09E667UL;
106 md->state[1] = 0xBB67AE85UL;
107 md->state[2] = 0x3C6EF372UL;
108 md->state[3] = 0xA54FF53AUL;
109 md->state[4] = 0x510E527FUL;
110 md->state[5] = 0x9B05688CUL;
111 md->state[6] = 0x1F83D9ABUL;
112 md->state[7] = 0x5BE0CD19UL;
113 }
114 /**
115 Process a block of memory though the hash
116 @param md The hash state
117 @param in The data to hash
118 @param inlen The length of the data (octets)
119 @return CRYPT_OK if successful
120 */
erofs_sha256_process(struct sha256_state * md,const unsigned char * in,unsigned long inlen)121 int erofs_sha256_process(struct sha256_state *md,
122 const unsigned char *in, unsigned long inlen)
123 {
124 unsigned long n;
125 #define block_size 64
126 if (md->curlen > sizeof(md->buf))
127 return -1;
128 while (inlen > 0) {
129 if (md->curlen == 0 && inlen >= block_size) {
130 if (sha256_compress(md, (unsigned char *) in) < 0)
131 return -1;
132 md->length += block_size * 8;
133 in += block_size;
134 inlen -= block_size;
135 } else {
136 n = MIN(inlen, (block_size - md->curlen));
137 memcpy(md->buf + md->curlen, in, n);
138 md->curlen += n;
139 in += n;
140 inlen -= n;
141 if (md->curlen == block_size) {
142 if (sha256_compress(md, md->buf) < 0)
143 return -1;
144 md->length += 8 * block_size;
145 md->curlen = 0;
146 }
147 }
148 }
149 return 0;
150 }
151 /**
152 Terminate the hash to get the digest
153 @param md The hash state
154 @param out [out] The destination of the hash (32 bytes)
155 @return CRYPT_OK if successful
156 */
erofs_sha256_done(struct sha256_state * md,unsigned char * out)157 int erofs_sha256_done(struct sha256_state *md, unsigned char *out)
158 {
159 int i;
160 if (md->curlen >= sizeof(md->buf))
161 return -1;
162 /* increase the length of the message */
163 md->length += md->curlen * 8;
164 /* append the '1' bit */
165 md->buf[md->curlen++] = (unsigned char) 0x80;
166 /* if the length is currently above 56 bytes we append zeros
167 * then compress. Then we can fall back to padding zeros and length
168 * encoding like normal.
169 */
170 if (md->curlen > 56) {
171 while (md->curlen < 64) {
172 md->buf[md->curlen++] = (unsigned char) 0;
173 }
174 sha256_compress(md, md->buf);
175 md->curlen = 0;
176 }
177 /* pad upto 56 bytes of zeroes */
178 while (md->curlen < 56) {
179 md->buf[md->curlen++] = (unsigned char) 0;
180 }
181 /* store length */
182 STORE64H(md->length, md->buf+56);
183 sha256_compress(md, md->buf);
184 /* copy output */
185 for (i = 0; i < 8; i++)
186 STORE32H(md->state[i], out + (4 * i));
187 return 0;
188 }
189
erofs_sha256(const unsigned char * in,unsigned long in_size,unsigned char out[32])190 void erofs_sha256(const unsigned char *in, unsigned long in_size,
191 unsigned char out[32])
192 {
193 struct sha256_state md;
194
195 erofs_sha256_init(&md);
196 erofs_sha256_process(&md, in, in_size);
197 erofs_sha256_done(&md, out);
198 }
199
200 #ifdef UNITTEST
201 #include <stdio.h>
202
203 static const struct {
204 char *msg;
205 unsigned char hash[32];
206 } tests[] = {
207 { "",
208 { 0xe3, 0xb0, 0xc4, 0x42, 0x98, 0xfc, 0x1c, 0x14,
209 0x9a, 0xfb, 0xf4, 0xc8, 0x99, 0x6f, 0xb9, 0x24,
210 0x27, 0xae, 0x41, 0xe4, 0x64, 0x9b, 0x93, 0x4c,
211 0xa4, 0x95, 0x99, 0x1b, 0x78, 0x52, 0xb8, 0x55 }
212 },
213 { "abc",
214 { 0xba, 0x78, 0x16, 0xbf, 0x8f, 0x01, 0xcf, 0xea,
215 0x41, 0x41, 0x40, 0xde, 0x5d, 0xae, 0x22, 0x23,
216 0xb0, 0x03, 0x61, 0xa3, 0x96, 0x17, 0x7a, 0x9c,
217 0xb4, 0x10, 0xff, 0x61, 0xf2, 0x00, 0x15, 0xad }
218 },
219 { "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq",
220 { 0x24, 0x8d, 0x6a, 0x61, 0xd2, 0x06, 0x38, 0xb8,
221 0xe5, 0xc0, 0x26, 0x93, 0x0c, 0x3e, 0x60, 0x39,
222 0xa3, 0x3c, 0xe4, 0x59, 0x64, 0xff, 0x21, 0x67,
223 0xf6, 0xec, 0xed, 0xd4, 0x19, 0xdb, 0x06, 0xc1 }
224 },
225 };
226
main(int argc,char ** argv)227 int main(int argc, char **argv)
228 {
229 int i;
230 int errors = 0;
231 unsigned char tmp[32];
232
233 for (i = 0; i < (int)(sizeof(tests) / sizeof(tests[0])); i++) {
234 unsigned char *msg = (unsigned char *) tests[i].msg;
235 int len = strlen(tests[i].msg);
236
237 erofs_sha256(msg, len, tmp);
238 printf("SHA256 test message %d: ", i);
239 if (memcmp(tmp, tests[i].hash, 32) != 0) {
240 printf("FAILED\n");
241 errors++;
242 } else
243 printf("OK\n");
244 }
245 return errors;
246 }
247
248 #endif /* UNITTEST */
249