3 This file is part of the ARM-Crypto-Lib.
4 Copyright (C) 2006-2010 Daniel Otte (daniel.otte@rub.de)
6 This program is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
27 * \brief SHA-256 implementation.
33 #include <string.h> /* for memcpy, memmove, memset */
38 #if defined LITTLE_ENDIAN
39 #elif defined BIG_ENDIAN
41 #error specify endianess!!!
45 /*************************************************************************/
48 uint32_t sha256_init_vector[]={
49 0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A,
50 0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19 };
53 /*************************************************************************/
56 * \brief \c sh256_init initialises a sha256 context for hashing.
57 * \c sh256_init c initialises the given sha256 context for hashing
58 * @param state pointer to a sha256 context
61 void sha256_init(sha256_ctx_t *state){
63 memcpy(state->h, sha256_init_vector, 8*4);
66 /*************************************************************************/
69 * rotate x right by n positions
71 uint32_t rotr32( uint32_t x, uint8_t n){
72 return ((x>>n) | (x<<(32-n)));
76 /*************************************************************************/
78 // #define CHANGE_ENDIAN32(x) (((x)<<24) | ((x)>>24) | (((x)& 0x0000ff00)<<8) | (((x)& 0x00ff0000)>>8))
80 uint32_t change_endian32(uint32_t x){
81 return (((x)<<24) | ((x)>>24) | (((x)& 0x0000ff00)<<8) | (((x)& 0x00ff0000)>>8));
85 /*************************************************************************/
87 /* sha256 functions as macros for speed and size, cause they are called only once */
89 #define CH(x,y,z) (((x)&(y)) ^ ((~(x))&(z)))
90 #define MAJ(x,y,z) (((x)&(y)) ^ ((x)&(z)) ^ ((y)&(z)))
92 #define SIGMA0(x) (rotr32((x),2) ^ rotr32((x),13) ^ rotr32((x),22))
93 #define SIGMA1(x) (rotr32((x),6) ^ rotr32((x),11) ^ rotr32((x),25))
94 #define SIGMA_a(x) (rotr32((x),7) ^ rotr32((x),18) ^ ((x)>>3))
95 #define SIGMA_b(x) (rotr32((x),17) ^ rotr32((x),19) ^ ((x)>>10))
99 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
100 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
101 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
102 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
103 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
104 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
105 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
106 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
110 /*************************************************************************/
113 * block must be, 512, Bit = 64, Byte, long !!!
115 void sha256_nextBlock (sha256_ctx_t *state, const void* block){
116 uint32_t w[64]; /* this is 256, byte, large, */
121 #if defined LITTLE_ENDIAN
122 for (i=0; i<16; ++i){
123 w[i]= change_endian32(((uint32_t*)block)[i]);
125 #elif defined BIG_ENDIAN
126 memcpy((void*)w, block, 64);
128 for (i=16; i<64; ++i){
129 w[i] = SIGMA_b(w[i-2]) + w[i-7] + SIGMA_a(w[i-15]) + w[i-16];
132 /* init working variables */
133 memcpy((void*)a,(void*)(state->h), 8*4);
135 /* do the, fun stuff, */
136 for (i=0; i<64; ++i){
137 t1 = a[7] + SIGMA1(a[4]) + CH(a[4],a[5],a[6]) + k[i] + w[i];
138 t2 = SIGMA0(a[0]) + MAJ(a[0],a[1],a[2]);
139 memmove(&(a[1]), &(a[0]), 7*4); /* a[7]=a[6]; a[6]=a[5]; a[5]=a[4]; a[4]=a[3]; a[3]=a[2]; a[2]=a[1]; a[1]=a[0]; */
144 /* update, the, state, */
148 state->length += 512;
152 /*************************************************************************/
155 * \brief function to process the last block being hashed
156 * @param state Pointer to the context in which this block should be processed.
157 * @param block Pointer to the message wich should be hashed.
158 * @param length is the length of only THIS block in BITS not in bytes!
159 * bits are big endian, meaning high bits come first.
160 * if you have a message with bits at the end, the byte must be padded with zeros
162 void sha256_lastBlock(sha256_ctx_t *state, const void* block, uint16_t length){
163 uint8_t lb[SHA256_BLOCK_BITS/8]; /* local block */
164 while(length>=SHA256_BLOCK_BITS){
165 sha256_nextBlock(state, block);
166 length -= SHA256_BLOCK_BITS;
167 block = (uint8_t*)block+SHA256_BLOCK_BYTES;
170 state->length += length;
171 memcpy (&(lb[0]), block, length/8);
173 /* set the final one bit */
174 if (length & 0x7){ // if we have single bits at the end
175 lb[length/8] = ((uint8_t*)(block))[length/8];
179 lb[length/8] |= 0x80>>(length & 0x7);
180 length =(length >> 3) + 1; /* from now on length contains the number of BYTES in lb*/
182 if (length>64-8){ /* not enouth space for 64bit length value */
183 memset((void*)(&(lb[length])), 0, 64-length);
184 sha256_nextBlock(state, lb);
185 state->length -= 512;
188 memset((void*)(&(lb[length])), 0, 56-length);
189 /* store the 64bit length value */
190 #if defined LITTLE_ENDIAN
191 /* this is now rolled up */
193 for (i=1; i<=8; ++i){
194 lb[55+i] = (uint8_t)(state->length>>(64- 8*i));
196 #elif defined BIG_ENDIAN
197 *((uint64_t)&(lb[56])) = state->length;
199 sha256_nextBlock(state, lb);
203 /*************************************************************************/
208 void sha256(sha256_hash_t *dest, const void* msg, uint32_t length){ /* length could be choosen longer but this is for µC */
211 while(length >= SHA256_BLOCK_BITS){
212 sha256_nextBlock(&s, msg);
213 msg = (uint8_t*)msg + SHA256_BLOCK_BITS/8;
214 length -= SHA256_BLOCK_BITS;
216 sha256_lastBlock(&s, msg, length);
217 sha256_ctx2hash(dest,&s);
222 /*************************************************************************/
224 void sha256_ctx2hash(sha256_hash_t *dest, const sha256_ctx_t *state){
225 #if defined LITTLE_ENDIAN
228 ((uint32_t*)dest)[i] = change_endian32(state->h[i]);
231 if (dest != state->h)
232 memcpy(dest, state->h, SHA256_HASH_BITS/8);
234 # error unsupported endian type!