1 #include "sha256.h"
2
3 /**
4 * SHA256 Hashing
5 * @addr: pointers to the data area
6 * @len: Lengths of the data block
7 * @res: Buffer for the digest
8 * Returns: 0 on success, -1 of failure
9 */
sha256(const unsigned char * addr,const size_t len,unsigned char * res)10 int sha256(const unsigned char *addr, const size_t len,
11 unsigned char *res)
12 {
13 struct sha256_state ctx;
14
15 sha256_init(&ctx);
16
17 if (sha256_process(&ctx, addr, len) || sha256_done(&ctx, res))
18 return -1;
19
20 return 0;
21 }
22
23 /** ===== start - public domain SHA256 implementation ===== */
24
25 /** This is based on SHA256 implementation in LibTomCrypt that was released into
26 * public domain by Tom St Denis.
27 */
28
29 /** the K array */
30 static const unsigned long K[64] = {
31 0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL, 0x3956c25bUL,
32 0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL, 0xd807aa98UL, 0x12835b01UL,
33 0x243185beUL, 0x550c7dc3UL, 0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL,
34 0xc19bf174UL, 0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
35 0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL, 0x983e5152UL,
36 0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL, 0xc6e00bf3UL, 0xd5a79147UL,
37 0x06ca6351UL, 0x14292967UL, 0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL,
38 0x53380d13UL, 0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
39 0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL, 0xd192e819UL,
40 0xd6990624UL, 0xf40e3585UL, 0x106aa070UL, 0x19a4c116UL, 0x1e376c08UL,
41 0x2748774cUL, 0x34b0bcb5UL, 0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL,
42 0x682e6ff3UL, 0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
43 0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL
44 };
45
46
47 /** Various logical functions */
48 #define RORc(x, y) \
49 (((((unsigned long) (x) & 0xFFFFFFFFUL) >> (unsigned long) ((y) & 31)) | \
50 ((unsigned long) (x) << (unsigned long) (32 - ((y) & 31)))) & 0xFFFFFFFFUL)
51 #define Ch(x, y, z) (z ^ (x & (y ^ z)))
52 #define Maj(x, y, z) (((x | y) & z) | (x & y))
53 #define S(x, n) RORc((x), (n))
54 #define R(x, n) (((x)&0xFFFFFFFFUL)>>(n))
55 #define Sigma0(x) (S(x, 2) ^ S(x, 13) ^ S(x, 22))
56 #define Sigma1(x) (S(x, 6) ^ S(x, 11) ^ S(x, 25))
57 #define Gamma0(x) (S(x, 7) ^ S(x, 18) ^ R(x, 3))
58 #define Gamma1(x) (S(x, 17) ^ S(x, 19) ^ R(x, 10))
59 #ifndef MIN
60 #define MIN(x, y) (((x) < (y)) ? (x) : (y))
61 #endif
62
63 /* compress 512-bits */
sha256_compress(struct sha256_state * md,const unsigned char * buf)64 static int sha256_compress(struct sha256_state *md, const unsigned char *buf)
65 {
66 __u32 S[8], W[64], t0, t1;
67 __u32 t;
68 int i;
69
70 /* copy state into S */
71 for (i = 0; i < 8; i++)
72 S[i] = md->state[i];
73
74 /* copy the state into 512-bits into W[0..15] */
75 for (i = 0; i < 16; i++)
76 W[i] = LOAD32B(buf + (4 * i));
77
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]) + W[i - 16];
81
82 /* Compress */
83 #define RND(a, b, c, d, e, f, g, h, i) \
84 t0 = h + Sigma1(e) + Ch(e, f, g) + K[i] + W[i]; \
85 t1 = Sigma0(a) + Maj(a, b, c); \
86 d += t0; \
87 h = t0 + t1;
88
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
95 /* feedback */
96 for (i = 0; i < 8; i++)
97 md->state[i] = md->state[i] + S[i];
98
99 return 0;
100 }
101
102
103 /* Initialize the hash state */
sha256_init(struct sha256_state * md)104 void sha256_init(struct sha256_state *md)
105 {
106 md->curlen = 0;
107 md->length = 0;
108 md->state[0] = 0x6A09E667UL;
109 md->state[1] = 0xBB67AE85UL;
110 md->state[2] = 0x3C6EF372UL;
111 md->state[3] = 0xA54FF53AUL;
112 md->state[4] = 0x510E527FUL;
113 md->state[5] = 0x9B05688CUL;
114 md->state[6] = 0x1F83D9ABUL;
115 md->state[7] = 0x5BE0CD19UL;
116 }
117
118 /**
119 * Process a block of memory though the hash
120 * @param md The hash state
121 * @param in The data to hash
122 * @param inlen The length of the data (octets)
123 * @return CRYPT_OK if successful
124 */
sha256_process(struct sha256_state * md,const unsigned char * in,unsigned long inlen)125 int sha256_process(struct sha256_state *md, const unsigned char *in,
126 unsigned long inlen)
127 {
128 unsigned long n;
129
130 if (md->curlen >= sizeof(md->buf))
131 return -1;
132
133 while (inlen > 0) {
134 if (md->curlen == 0 && inlen >= SHA256_BLOCK_SIZE) {
135 if (sha256_compress(md, (unsigned char *) in) < 0)
136 return -1;
137 md->length += SHA256_BLOCK_SIZE * 8;
138 in += SHA256_BLOCK_SIZE;
139 inlen -= SHA256_BLOCK_SIZE;
140 } else {
141 n = MIN(inlen, (SHA256_BLOCK_SIZE - md->curlen));
142 memcpy(md->buf + md->curlen, in, n);
143 md->curlen += n;
144 in += n;
145 inlen -= n;
146 if (md->curlen == SHA256_BLOCK_SIZE) {
147 if (sha256_compress(md, md->buf) < 0)
148 return -1;
149 md->length += 8 * SHA256_BLOCK_SIZE;
150 md->curlen = 0;
151 }
152 }
153 }
154
155 return 0;
156 }
157
158
159 /**
160 * Terminate the hash to get the digest
161 * @param md The hash state
162 * @param out [out] The destination of the hash (32 bytes)
163 * @return CRYPT_OK if successful
164 */
sha256_done(struct sha256_state * md,unsigned char * out)165 int sha256_done(struct sha256_state *md, unsigned char *out)
166 {
167 int i;
168
169 if (md->curlen >= sizeof(md->buf))
170 return -1;
171
172 /* increase the length of the message */
173 md->length += md->curlen * 8;
174
175 /* append the '1' bit */
176 md->buf[md->curlen++] = (unsigned char) 0x80;
177
178 /* if the length is currently above 56 bytes we append zeros
179 * then compress. Then we can fall back to padding zeros and length
180 * encoding like normal.
181 */
182 if (md->curlen > 56) {
183 while (md->curlen < SHA256_BLOCK_SIZE)
184 md->buf[md->curlen++] = (unsigned char) 0;
185
186 sha256_compress(md, md->buf);
187 md->curlen = 0;
188 }
189
190 /* pad up to 56 bytes of zeroes */
191 while (md->curlen < 56)
192 md->buf[md->curlen++] = (unsigned char) 0;
193
194 /* store length */
195 STORE64B(md->buf + 56, md->length);
196 sha256_compress(md, md->buf);
197
198 /* copy output */
199 for (i = 0; i < 8; i++)
200 STORE32B(out + (4 * i), md->state[i]);
201
202 return 0;
203 }
204
205 /* ===== end - public domain SHA256 implementation ===== */
206