1 /*
2  * SHA-256 hash implementation and interface functions
3  * Copyright (c) 2003-2011, Jouni Malinen <j@w1.fi>
4  *
5  * This software may be distributed under the terms of the BSD license.
6  * See README for more details.
7  */
8 
9 #include "includes.h"
10 
11 #include "common.h"
12 #include "sha256.h"
13 #include "sha256_i.h"
14 #include "crypto.h"
15 
16 
17 /**
18  * sha256_vector - SHA256 hash for data vector
19  * @num_elem: Number of elements in the data vector
20  * @addr: Pointers to the data areas
21  * @len: Lengths of the data blocks
22  * @mac: Buffer for the hash
23  * Returns: 0 on success, -1 of failure
24  */
sha256_vector(size_t num_elem,const u8 * addr[],const size_t * len,u8 * mac)25 int sha256_vector(size_t num_elem, const u8 *addr[], const size_t *len,
26 		  u8 *mac)
27 {
28 	struct sha256_state ctx;
29 	size_t i;
30 
31 	sha256_init(&ctx);
32 	for (i = 0; i < num_elem; i++)
33 		if (sha256_process(&ctx, addr[i], len[i]))
34 			return -1;
35 	if (sha256_done(&ctx, mac))
36 		return -1;
37 	return 0;
38 }
39 
40 
41 /* ===== start - public domain SHA256 implementation ===== */
42 
43 /* This is based on SHA256 implementation in LibTomCrypt that was released into
44  * public domain by Tom St Denis. */
45 
46 /* the K array */
47 static const unsigned long K[64] = {
48 	0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL, 0x3956c25bUL,
49 	0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL, 0xd807aa98UL, 0x12835b01UL,
50 	0x243185beUL, 0x550c7dc3UL, 0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL,
51 	0xc19bf174UL, 0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
52 	0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL, 0x983e5152UL,
53 	0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL, 0xc6e00bf3UL, 0xd5a79147UL,
54 	0x06ca6351UL, 0x14292967UL, 0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL,
55 	0x53380d13UL, 0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
56 	0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL, 0xd192e819UL,
57 	0xd6990624UL, 0xf40e3585UL, 0x106aa070UL, 0x19a4c116UL, 0x1e376c08UL,
58 	0x2748774cUL, 0x34b0bcb5UL, 0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL,
59 	0x682e6ff3UL, 0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
60 	0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL
61 };
62 
63 
64 /* Various logical functions */
65 #define RORc(x, y) \
66 ( ((((unsigned long) (x) & 0xFFFFFFFFUL) >> (unsigned long) ((y) & 31)) | \
67    ((unsigned long) (x) << (unsigned long) (32 - ((y) & 31)))) & 0xFFFFFFFFUL)
68 #define Ch(x,y,z)       (z ^ (x & (y ^ z)))
69 #define Maj(x,y,z)      (((x | y) & z) | (x & y))
70 #define S(x, n)         RORc((x), (n))
71 #define R(x, n)         (((x)&0xFFFFFFFFUL)>>(n))
72 #define Sigma0(x)       (S(x, 2) ^ S(x, 13) ^ S(x, 22))
73 #define Sigma1(x)       (S(x, 6) ^ S(x, 11) ^ S(x, 25))
74 #define Gamma0(x)       (S(x, 7) ^ S(x, 18) ^ R(x, 3))
75 #define Gamma1(x)       (S(x, 17) ^ S(x, 19) ^ R(x, 10))
76 #ifndef MIN
77 #define MIN(x, y) (((x) < (y)) ? (x) : (y))
78 #endif
79 
80 /* compress 512-bits */
sha256_compress(struct sha256_state * md,unsigned char * buf)81 static int sha256_compress(struct sha256_state *md, unsigned char *buf)
82 {
83 	u32 S[8], W[64], t0, t1;
84 	u32 t;
85 	int i;
86 
87 	/* copy state into S */
88 	for (i = 0; i < 8; i++) {
89 		S[i] = md->state[i];
90 	}
91 
92 	/* copy the state into 512-bits into W[0..15] */
93 	for (i = 0; i < 16; i++)
94 		W[i] = WPA_GET_BE32(buf + (4 * i));
95 
96 	/* fill W[16..63] */
97 	for (i = 16; i < 64; i++) {
98 		W[i] = Gamma1(W[i - 2]) + W[i - 7] + Gamma0(W[i - 15]) +
99 			W[i - 16];
100 	}
101 
102 	/* Compress */
103 #define RND(a,b,c,d,e,f,g,h,i)                          \
104 	t0 = h + Sigma1(e) + Ch(e, f, g) + K[i] + W[i];	\
105 	t1 = Sigma0(a) + Maj(a, b, c);			\
106 	d += t0;					\
107 	h  = t0 + t1;
108 
109 	for (i = 0; i < 64; ++i) {
110 		RND(S[0], S[1], S[2], S[3], S[4], S[5], S[6], S[7], i);
111 		t = S[7]; S[7] = S[6]; S[6] = S[5]; S[5] = S[4];
112 		S[4] = S[3]; S[3] = S[2]; S[2] = S[1]; S[1] = S[0]; S[0] = t;
113 	}
114 
115 	/* feedback */
116 	for (i = 0; i < 8; i++) {
117 		md->state[i] = md->state[i] + S[i];
118 	}
119 	return 0;
120 }
121 
122 
123 /* Initialize the hash state */
sha256_init(struct sha256_state * md)124 void sha256_init(struct sha256_state *md)
125 {
126 	md->curlen = 0;
127 	md->length = 0;
128 	md->state[0] = 0x6A09E667UL;
129 	md->state[1] = 0xBB67AE85UL;
130 	md->state[2] = 0x3C6EF372UL;
131 	md->state[3] = 0xA54FF53AUL;
132 	md->state[4] = 0x510E527FUL;
133 	md->state[5] = 0x9B05688CUL;
134 	md->state[6] = 0x1F83D9ABUL;
135 	md->state[7] = 0x5BE0CD19UL;
136 }
137 
138 /**
139    Process a block of memory though the hash
140    @param md     The hash state
141    @param in     The data to hash
142    @param inlen  The length of the data (octets)
143    @return CRYPT_OK if successful
144 */
sha256_process(struct sha256_state * md,const unsigned char * in,unsigned long inlen)145 int sha256_process(struct sha256_state *md, const unsigned char *in,
146 		   unsigned long inlen)
147 {
148 	unsigned long n;
149 
150 	if (md->curlen >= sizeof(md->buf))
151 		return -1;
152 
153 	while (inlen > 0) {
154 		if (md->curlen == 0 && inlen >= SHA256_BLOCK_SIZE) {
155 			if (sha256_compress(md, (unsigned char *) in) < 0)
156 				return -1;
157 			md->length += SHA256_BLOCK_SIZE * 8;
158 			in += SHA256_BLOCK_SIZE;
159 			inlen -= SHA256_BLOCK_SIZE;
160 		} else {
161 			n = MIN(inlen, (SHA256_BLOCK_SIZE - md->curlen));
162 			os_memcpy(md->buf + md->curlen, in, n);
163 			md->curlen += n;
164 			in += n;
165 			inlen -= n;
166 			if (md->curlen == SHA256_BLOCK_SIZE) {
167 				if (sha256_compress(md, md->buf) < 0)
168 					return -1;
169 				md->length += 8 * SHA256_BLOCK_SIZE;
170 				md->curlen = 0;
171 			}
172 		}
173 	}
174 
175 	return 0;
176 }
177 
178 
179 /**
180    Terminate the hash to get the digest
181    @param md  The hash state
182    @param out [out] The destination of the hash (32 bytes)
183    @return CRYPT_OK if successful
184 */
sha256_done(struct sha256_state * md,unsigned char * out)185 int sha256_done(struct sha256_state *md, unsigned char *out)
186 {
187 	int i;
188 
189 	if (md->curlen >= sizeof(md->buf))
190 		return -1;
191 
192 	/* increase the length of the message */
193 	md->length += md->curlen * 8;
194 
195 	/* append the '1' bit */
196 	md->buf[md->curlen++] = (unsigned char) 0x80;
197 
198 	/* if the length is currently above 56 bytes we append zeros
199 	 * then compress.  Then we can fall back to padding zeros and length
200 	 * encoding like normal.
201 	 */
202 	if (md->curlen > 56) {
203 		while (md->curlen < SHA256_BLOCK_SIZE) {
204 			md->buf[md->curlen++] = (unsigned char) 0;
205 		}
206 		sha256_compress(md, md->buf);
207 		md->curlen = 0;
208 	}
209 
210 	/* pad up to 56 bytes of zeroes */
211 	while (md->curlen < 56) {
212 		md->buf[md->curlen++] = (unsigned char) 0;
213 	}
214 
215 	/* store length */
216 	WPA_PUT_BE64(md->buf + 56, md->length);
217 	sha256_compress(md, md->buf);
218 
219 	/* copy output */
220 	for (i = 0; i < 8; i++)
221 		WPA_PUT_BE32(out + (4 * i), md->state[i]);
222 
223 	return 0;
224 }
225 
226 /* ===== end - public domain SHA256 implementation ===== */
227