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      1 /*
      2  * SHA-256 hash implementation and interface functions
      3  * Copyright (c) 2003-2011, Jouni Malinen <j (at) 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  */
     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 */
     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 */
    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 */
    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 */
    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