2 * SHA1 hash algorithm. Used in SSH2 as a MAC, and the transform is
3 * also used as a `stirring' function for the PuTTY random number
4 * pool. Implemented directly from the specification by Simon
10 /* ----------------------------------------------------------------------
11 * Core SHA algorithm: processes 16-word blocks into a message digest.
14 #define rol(x,y) ( ((x) << (y)) | (((uint32)x) >> (32-y)) )
16 void SHA_Core_Init(uint32 h[5]) {
24 void SHATransform(word32 *digest, word32 *block) {
29 for (t = 0; t < 16; t++)
32 for (t = 16; t < 80; t++) {
33 word32 tmp = w[t-3] ^ w[t-8] ^ w[t-14] ^ w[t-16];
43 for (t = 0; t < 20; t++) {
44 word32 tmp = rol(a, 5) + ( (b&c) | (d&~b) ) + e + w[t] + 0x5a827999;
45 e = d; d = c; c = rol(b, 30); b = a; a = tmp;
47 for (t = 20; t < 40; t++) {
48 word32 tmp = rol(a, 5) + (b^c^d) + e + w[t] + 0x6ed9eba1;
49 e = d; d = c; c = rol(b, 30); b = a; a = tmp;
51 for (t = 40; t < 60; t++) {
52 word32 tmp = rol(a, 5) + ( (b&c) | (b&d) | (c&d) ) + e + w[t] + 0x8f1bbcdc;
53 e = d; d = c; c = rol(b, 30); b = a; a = tmp;
55 for (t = 60; t < 80; t++) {
56 word32 tmp = rol(a, 5) + (b^c^d) + e + w[t] + 0xca62c1d6;
57 e = d; d = c; c = rol(b, 30); b = a; a = tmp;
67 /* ----------------------------------------------------------------------
68 * Outer SHA algorithm: take an arbitrary length byte string,
69 * convert it into 16-word blocks with the prescribed padding at
70 * the end, and pass those blocks to the core SHA algorithm.
73 void SHA_Init(SHA_State *s) {
76 s->lenhi = s->lenlo = 0;
79 void SHA_Bytes(SHA_State *s, void *p, int len) {
80 unsigned char *q = (unsigned char *)p;
86 * Update the length field.
89 s->lenhi += (s->lenlo < lenw);
91 if (s->blkused && s->blkused+len < 64) {
93 * Trivial case: just add to the block.
95 memcpy(s->block + s->blkused, q, len);
99 * We must complete and process at least one block.
101 while (s->blkused + len >= 64) {
102 memcpy(s->block + s->blkused, q, 64 - s->blkused);
103 q += 64 - s->blkused;
104 len -= 64 - s->blkused;
105 /* Now process the block. Gather bytes big-endian into words */
106 for (i = 0; i < 16; i++) {
108 ( ((uint32)s->block[i*4+0]) << 24 ) |
109 ( ((uint32)s->block[i*4+1]) << 16 ) |
110 ( ((uint32)s->block[i*4+2]) << 8 ) |
111 ( ((uint32)s->block[i*4+3]) << 0 );
113 SHATransform(s->h, wordblock);
116 memcpy(s->block, q, len);
121 void SHA_Final(SHA_State *s, unsigned char *output) {
127 if (s->blkused >= 56)
128 pad = 56 + 64 - s->blkused;
130 pad = 56 - s->blkused;
132 lenhi = (s->lenhi << 3) | (s->lenlo >> (32-3));
133 lenlo = (s->lenlo << 3);
137 SHA_Bytes(s, &c, pad);
139 c[0] = (lenhi >> 24) & 0xFF;
140 c[1] = (lenhi >> 16) & 0xFF;
141 c[2] = (lenhi >> 8) & 0xFF;
142 c[3] = (lenhi >> 0) & 0xFF;
143 c[4] = (lenlo >> 24) & 0xFF;
144 c[5] = (lenlo >> 16) & 0xFF;
145 c[6] = (lenlo >> 8) & 0xFF;
146 c[7] = (lenlo >> 0) & 0xFF;
150 for (i = 0; i < 5; i++) {
151 output[i*4 ] = (s->h[i] >> 24) & 0xFF;
152 output[i*4+1] = (s->h[i] >> 16) & 0xFF;
153 output[i*4+2] = (s->h[i] >> 8) & 0xFF;
154 output[i*4+3] = (s->h[i] ) & 0xFF;
158 void SHA_Simple(void *p, int len, unsigned char *output) {
162 SHA_Bytes(&s, p, len);
163 SHA_Final(&s, output);
166 /* ----------------------------------------------------------------------
167 * The above is the SHA-1 algorithm itself. Now we implement the
168 * HMAC wrapper on it.
171 static SHA_State sha1_cs_mac_s1, sha1_cs_mac_s2;
172 static SHA_State sha1_sc_mac_s1, sha1_sc_mac_s2;
174 static void sha1_key(SHA_State *s1, SHA_State *s2,
175 unsigned char *key, int len) {
176 unsigned char foo[64];
179 memset(foo, 0x36, 64);
180 for (i = 0; i < len && i < 64; i++)
183 SHA_Bytes(s1, foo, 64);
185 memset(foo, 0x5C, 64);
186 for (i = 0; i < len && i < 64; i++)
189 SHA_Bytes(s2, foo, 64);
191 memset(foo, 0, 64); /* burn the evidence */
194 static void sha1_cskey(unsigned char *key) {
195 sha1_key(&sha1_cs_mac_s1, &sha1_cs_mac_s2, key, 20);
198 static void sha1_sckey(unsigned char *key) {
199 sha1_key(&sha1_sc_mac_s1, &sha1_sc_mac_s2, key, 20);
202 static void sha1_cskey_buggy(unsigned char *key) {
203 sha1_key(&sha1_cs_mac_s1, &sha1_cs_mac_s2, key, 16);
206 static void sha1_sckey_buggy(unsigned char *key) {
207 sha1_key(&sha1_sc_mac_s1, &sha1_sc_mac_s2, key, 16);
210 static void sha1_do_hmac(SHA_State *s1, SHA_State *s2,
211 unsigned char *blk, int len, unsigned long seq,
212 unsigned char *hmac) {
214 unsigned char intermediate[20];
216 intermediate[0] = (unsigned char)((seq >> 24) & 0xFF);
217 intermediate[1] = (unsigned char)((seq >> 16) & 0xFF);
218 intermediate[2] = (unsigned char)((seq >> 8) & 0xFF);
219 intermediate[3] = (unsigned char)((seq ) & 0xFF);
221 s = *s1; /* structure copy */
222 SHA_Bytes(&s, intermediate, 4);
223 SHA_Bytes(&s, blk, len);
224 SHA_Final(&s, intermediate);
225 s = *s2; /* structure copy */
226 SHA_Bytes(&s, intermediate, 20);
230 static void sha1_generate(unsigned char *blk, int len, unsigned long seq) {
231 sha1_do_hmac(&sha1_cs_mac_s1, &sha1_cs_mac_s2, blk, len, seq, blk+len);
234 static int sha1_verify(unsigned char *blk, int len, unsigned long seq) {
235 unsigned char correct[20];
236 sha1_do_hmac(&sha1_sc_mac_s1, &sha1_sc_mac_s2, blk, len, seq, correct);
237 return !memcmp(correct, blk+len, 20);
240 struct ssh_mac ssh_sha1 = {
241 sha1_cskey, sha1_sckey,
248 struct ssh_mac ssh_sha1_buggy = {
249 sha1_cskey_buggy, sha1_sckey_buggy,