3 This file is part of the Crypto-avr-lib/microcrypt-lib.
4 Copyright (C) 2008 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/>.
25 * \brief SHA-1 implementation.
29 #include <string.h> /* memcpy & co */
38 /********************************************************************************************************/
41 * \brief initialises given SHA-1 context
44 void sha1_init(sha1_ctx_t *state){
45 DEBUG_S("\r\nSHA1_INIT");
46 state->h[0] = 0x67452301;
47 state->h[1] = 0xefcdab89;
48 state->h[2] = 0x98badcfe;
49 state->h[3] = 0x10325476;
50 state->h[4] = 0xc3d2e1f0;
54 /********************************************************************************************************/
55 /* some helping functions */
56 uint32_t rotl32(uint32_t n, uint8_t bits){
57 return ((n<<bits) | (n>>(32-bits)));
60 uint32_t change_endian32(uint32_t x){
61 return (((x)<<24) | ((x)>>24) | (((x)& 0x0000ff00)<<8) | (((x)& 0x00ff0000)>>8));
65 /* three SHA-1 inner functions */
66 uint32_t ch(uint32_t x, uint32_t y, uint32_t z){
68 return ((x&y)^((~x)&z));
71 uint32_t maj(uint32_t x, uint32_t y, uint32_t z){
73 return ((x&y)^(x&z)^(y&z));
76 uint32_t parity(uint32_t x, uint32_t y, uint32_t z){
77 DEBUG_S("\r\nPARITY");
81 /********************************************************************************************************/
83 * \brief "add" a block to the hash
84 * This is the core function of the hash algorithm. To understand how it's working
85 * and what thoese variables do, take a look at FIPS-182. This is an "alternativ" implementation
88 #define MASK 0x0000000f
90 typedef uint32_t (*pf_t)(uint32_t x, uint32_t y, uint32_t z);
92 void sha1_nextBlock (sha1_ctx_t *state, void* block){
97 pf_t f[] = {ch,parity,maj,parity};
98 uint32_t k[4]={ 0x5a827999,
103 /* load the w array (changing the endian and so) */
105 w[t] = change_endian32(((uint32_t*)block)[t]);
109 for(dbgi=0; dbgi<16; ++dbgi){
110 DEBUG_S("\n\rBlock:");
114 uart_hexdump(&(w[dbgi]) ,4);
120 memcpy(a, state->h, 5*sizeof(uint32_t));
124 for(t=0; t<=79; ++t){
128 DEBUG_S("\r\n ws = "); uart_hexdump(&ws, 4);
130 w[s] = rotl32( w[(s+13)&MASK] ^ w[(s+8)&MASK] ^
131 w[(s+ 2)&MASK] ^ w[s] ,1);
133 DEBUG_S(" --> ws = "); uart_hexdump(&(w[s]), 4);
138 temp = rotl32(a[0],5) + (dtemp=f[t/20](a[1],a[2],a[3])) + a[4] + k[t/20] + w[s];
139 memmove(&(a[1]), &(a[0]), 4*sizeof(uint32_t)); /* e=d; d=c; c=b; b=a; */
141 a[2] = rotl32(a[2],30); /* we might also do rotr32(c,2) */
144 DEBUG_S("\r\nt = "); DEBUG_B(t);
147 uart_hexdump(a, 5*4);
151 uart_hexdump(&(k[t/20]), 4);
153 DEBUG_S("; f(b,c,d) = ");
155 uart_hexdump(&dtemp, 4);
159 /* update the state */
163 state->length += 512;
166 /********************************************************************************************************/
168 void sha1_lastBlock(sha1_ctx_t *state, void* block, uint16_t length){
169 uint8_t lb[SHA1_BLOCK_BITS/8]; /* local block */
170 state->length += length;
171 memcpy (&(lb[0]), block, length/8);
173 /* set the final one bit */
174 if (length & 0x3){ /* if we have single bits at the end */
175 lb[length/8] = ((uint8_t*)(block))[length/8];
179 lb[length/8] |= 0x80>>(length & 0x3);
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 sha1_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 sha1_nextBlock(state, lb);
202 /********************************************************************************************************/
204 void sha1_ctx2hash (sha1_hash_t *dest, sha1_ctx_t *state){
205 #if defined LITTLE_ENDIAN
208 ((uint32_t*)dest)[i] = change_endian32(state->h[i]);
211 if (dest != state->h)
212 memcpy(dest, state->h, SHA256_HASH_BITS/8);
214 # error unsupported endian type!
218 /********************************************************************************************************/
223 void sha1 (sha1_hash_t *dest, void* msg, uint32_t length){
225 DEBUG_S("\r\nBLA BLUB");
227 while(length & (~0x0001ff)){ /* length>=512 */
228 DEBUG_S("\r\none block");
229 sha1_nextBlock(&s, msg);
230 msg += SHA1_BLOCK_BITS/8; /* increment pointer to next block */
231 length -= SHA1_BLOCK_BITS;
233 sha1_lastBlock(&s, msg, length);
234 sha1_ctx2hash(dest, &s);