7 * \brief SHA-1 implementation.
11 #include <string.h> /* memcpy & co */
20 /********************************************************************************************************/
23 * \brief initialises given SHA-1 context
26 void sha1_init(sha1_ctx_t *state){
27 DEBUG_S("\r\nSHA1_INIT");
28 state->h[0] = 0x67452301;
29 state->h[1] = 0xefcdab89;
30 state->h[2] = 0x98badcfe;
31 state->h[3] = 0x10325476;
32 state->h[4] = 0xc3d2e1f0;
36 /********************************************************************************************************/
37 /* some helping functions */
38 uint32_t rotl32(uint32_t n, uint8_t bits){
39 return ((n<<bits) | (n>>(32-bits)));
42 uint32_t change_endian32(uint32_t x){
43 return (((x)<<24) | ((x)>>24) | (((x)& 0x0000ff00)<<8) | (((x)& 0x00ff0000)>>8));
47 /* three SHA-1 inner functions */
48 uint32_t ch(uint32_t x, uint32_t y, uint32_t z){
50 return ((x&y)^((~x)&z));
53 uint32_t maj(uint32_t x, uint32_t y, uint32_t z){
55 return ((x&y)^(x&z)^(y&z));
58 uint32_t parity(uint32_t x, uint32_t y, uint32_t z){
59 DEBUG_S("\r\nPARITY");
63 /********************************************************************************************************/
65 * \brief "add" a block to the hash
66 * This is the core function of the hash algorithm. To understand how it's working
67 * and what thoese variables do, take a look at FIPS-182. This is an "alternativ" implementation
70 #define MASK 0x0000000f
72 typedef uint32_t (*pf_t)(uint32_t x, uint32_t y, uint32_t z);
74 void sha1_nextBlock (sha1_ctx_t *state, void* block){
79 pf_t f[] = {ch,parity,maj,parity};
80 uint32_t k[4]={ 0x5a827999,
85 /* load the w array (changing the endian and so) */
87 w[t] = change_endian32(((uint32_t*)block)[t]);
91 for(dbgi=0; dbgi<16; ++dbgi){
92 DEBUG_S("\n\rBlock:");
96 uart_hexdump(&(w[dbgi]) ,4);
102 memcpy(a, state->h, 5*sizeof(uint32_t));
106 for(t=0; t<=79; ++t){
110 DEBUG_S("\r\n ws = "); uart_hexdump(&ws, 4);
112 w[s] = rotl32( w[(s+13)&MASK] ^ w[(s+8)&MASK] ^
113 w[(s+ 2)&MASK] ^ w[s] ,1);
115 DEBUG_S(" --> ws = "); uart_hexdump(&(w[s]), 4);
120 temp = rotl32(a[0],5) + (dtemp=f[t/20](a[1],a[2],a[3])) + a[4] + k[t/20] + w[s];
121 memmove(&(a[1]), &(a[0]), 4*sizeof(uint32_t)); /* e=d; d=c; c=b; b=a; */
123 a[2] = rotl32(a[2],30); /* we might also do rotr32(c,2) */
126 DEBUG_S("\r\nt = "); DEBUG_B(t);
129 uart_hexdump(a, 5*4);
133 uart_hexdump(&(k[t/20]), 4);
135 DEBUG_S("; f(b,c,d) = ");
137 uart_hexdump(&dtemp, 4);
141 /* update the state */
145 state->length += 512;
148 /********************************************************************************************************/
150 void sha1_lastBlock(sha1_ctx_t *state, void* block, uint16_t length){
151 uint8_t lb[SHA1_BLOCK_BITS/8]; /* local block */
152 state->length += length;
153 memcpy (&(lb[0]), block, length/8);
155 /* set the final one bit */
156 if (length & 0x3){ /* if we have single bits at the end */
157 lb[length/8] = ((uint8_t*)(block))[length/8];
161 lb[length/8] |= 0x80>>(length & 0x3);
162 length =(length >> 3) + 1; /* from now on length contains the number of BYTES in lb*/
164 if (length>64-8){ /* not enouth space for 64bit length value */
165 memset((void*)(&(lb[length])), 0, 64-length);
166 sha1_nextBlock(state, lb);
167 state->length -= 512;
170 memset((void*)(&(lb[length])), 0, 56-length);
171 /* store the 64bit length value */
172 #if defined LITTLE_ENDIAN
173 /* this is now rolled up */
175 for (i=1; i<=8; ++i){
176 lb[55+i] = (uint8_t)(state->length>>(64- 8*i));
178 #elif defined BIG_ENDIAN
179 *((uint64_t)&(lb[56])) = state->length;
181 sha1_nextBlock(state, lb);
184 /********************************************************************************************************/
186 void sha1_ctx2hash (sha1_hash_t *dest, sha1_ctx_t *state){
187 #if defined LITTLE_ENDIAN
190 ((uint32_t*)dest)[i] = change_endian32(state->h[i]);
193 if (dest != state->h)
194 memcpy(dest, state->h, SHA256_HASH_BITS/8);
196 # error unsupported endian type!
200 /********************************************************************************************************/
205 void sha1 (sha1_hash_t *dest, void* msg, uint32_t length){
207 DEBUG_S("\r\nBLA BLUB");
209 while(length & (~0x0001ff)){ /* length>=512 */
210 DEBUG_S("\r\none block");
211 sha1_nextBlock(&s, msg);
212 msg += SHA1_BLOCK_BITS/8; /* increment pointer to next block */
213 length -= SHA1_BLOCK_BITS;
215 sha1_lastBlock(&s, msg, length);
216 sha1_ctx2hash(dest, &s);