1 #include <stdarg.h> /* FIXME */
2 #include <windows.h> /* FIXME */
3 #include "putty.h" /* FIXME */
6 * SHA1 hash algorithm. Used in SSH2 as a MAC, and the transform is
7 * also used as a `stirring' function for the PuTTY random number
8 * pool. Implemented directly from the specification by Simon
14 typedef unsigned int uint32;
16 /* ----------------------------------------------------------------------
17 * Core SHA algorithm: processes 16-word blocks into a message digest.
20 #define rol(x,y) ( ((x) << (y)) | (((uint32)x) >> (32-y)) )
22 void SHA_Core_Init(uint32 h[5]) {
30 void SHATransform(word32 *digest, word32 *block) {
35 for (t = 0; t < 16; t++)
38 for (t = 16; t < 80; t++) {
39 word32 tmp = w[t-3] ^ w[t-8] ^ w[t-14] ^ w[t-16];
49 for (t = 0; t < 20; t++) {
50 word32 tmp = rol(a, 5) + ( (b&c) | (d&~b) ) + e + w[t] + 0x5a827999;
51 e = d; d = c; c = rol(b, 30); b = a; a = tmp;
53 for (t = 20; t < 40; t++) {
54 word32 tmp = rol(a, 5) + (b^c^d) + e + w[t] + 0x6ed9eba1;
55 e = d; d = c; c = rol(b, 30); b = a; a = tmp;
57 for (t = 40; t < 60; t++) {
58 word32 tmp = rol(a, 5) + ( (b&c) | (b&d) | (c&d) ) + e + w[t] + 0x8f1bbcdc;
59 e = d; d = c; c = rol(b, 30); b = a; a = tmp;
61 for (t = 60; t < 80; t++) {
62 word32 tmp = rol(a, 5) + (b^c^d) + e + w[t] + 0xca62c1d6;
63 e = d; d = c; c = rol(b, 30); b = a; a = tmp;
73 /* ----------------------------------------------------------------------
74 * Outer SHA algorithm: take an arbitrary length byte string,
75 * convert it into 16-word blocks with the prescribed padding at
76 * the end, and pass those blocks to the core SHA algorithm.
79 void SHA_Init(SHA_State *s) {
82 s->lenhi = s->lenlo = 0;
85 void SHA_Bytes(SHA_State *s, void *p, int len) {
86 unsigned char *q = (unsigned char *)p;
92 * Update the length field.
95 s->lenhi += (s->lenlo < lenw);
97 if (s->blkused && s->blkused+len < 64) {
99 * Trivial case: just add to the block.
101 memcpy(s->block + s->blkused, q, len);
105 * We must complete and process at least one block.
107 while (s->blkused + len >= 64) {
108 memcpy(s->block + s->blkused, q, 64 - s->blkused);
109 q += 64 - s->blkused;
110 len -= 64 - s->blkused;
111 /* Now process the block. Gather bytes big-endian into words */
112 for (i = 0; i < 16; i++) {
114 ( ((uint32)s->block[i*4+0]) << 24 ) |
115 ( ((uint32)s->block[i*4+1]) << 16 ) |
116 ( ((uint32)s->block[i*4+2]) << 8 ) |
117 ( ((uint32)s->block[i*4+3]) << 0 );
119 SHATransform(s->h, wordblock);
122 memcpy(s->block, q, len);
127 void SHA_Final(SHA_State *s, unsigned char *output) {
133 if (s->blkused >= 56)
134 pad = 56 + 64 - s->blkused;
136 pad = 56 - s->blkused;
138 lenhi = (s->lenhi << 3) | (s->lenlo >> (32-3));
139 lenlo = (s->lenlo << 3);
143 SHA_Bytes(s, &c, pad);
145 c[0] = (lenhi >> 24) & 0xFF;
146 c[1] = (lenhi >> 16) & 0xFF;
147 c[2] = (lenhi >> 8) & 0xFF;
148 c[3] = (lenhi >> 0) & 0xFF;
149 c[4] = (lenlo >> 24) & 0xFF;
150 c[5] = (lenlo >> 16) & 0xFF;
151 c[6] = (lenlo >> 8) & 0xFF;
152 c[7] = (lenlo >> 0) & 0xFF;
156 for (i = 0; i < 5; i++) {
157 output[i*4 ] = (s->h[i] >> 24) & 0xFF;
158 output[i*4+1] = (s->h[i] >> 16) & 0xFF;
159 output[i*4+2] = (s->h[i] >> 8) & 0xFF;
160 output[i*4+3] = (s->h[i] ) & 0xFF;
164 void SHA_Simple(void *p, int len, unsigned char *output) {
168 SHA_Bytes(&s, p, len);
169 SHA_Final(&s, output);
172 /* ----------------------------------------------------------------------
173 * The above is the SHA-1 algorithm itself. Now we implement the
174 * HMAC wrapper on it.
177 static SHA_State sha1_cs_mac_s1, sha1_cs_mac_s2;
178 static SHA_State sha1_sc_mac_s1, sha1_sc_mac_s2;
180 static void sha1_key(SHA_State *s1, SHA_State *s2,
181 unsigned char *key, int len) {
182 unsigned char foo[64];
185 debug(("Key supplied is:\r\n"));
186 for (j=0; j<len; j++) debug((" %02X", key[j]));
190 memset(foo, 0x36, 64);
191 for (i = 0; i < len && i < 64; i++)
194 SHA_Bytes(s1, foo, 64);
196 memset(foo, 0x5C, 64);
197 for (i = 0; i < len && i < 64; i++)
200 SHA_Bytes(s2, foo, 64);
202 memset(foo, 0, 64); /* burn the evidence */
205 static void sha1_cskey(unsigned char *key) {
206 sha1_key(&sha1_cs_mac_s1, &sha1_cs_mac_s2, key, 20);
209 static void sha1_sckey(unsigned char *key) {
210 sha1_key(&sha1_sc_mac_s1, &sha1_sc_mac_s2, key, 20);
213 static void sha1_do_hmac(SHA_State *s1, SHA_State *s2,
214 unsigned char *blk, int len, unsigned long seq,
215 unsigned char *hmac) {
217 unsigned char intermediate[20];
219 intermediate[0] = (unsigned char)((seq >> 24) & 0xFF);
220 intermediate[1] = (unsigned char)((seq >> 16) & 0xFF);
221 intermediate[2] = (unsigned char)((seq >> 8) & 0xFF);
222 intermediate[3] = (unsigned char)((seq ) & 0xFF);
224 s = *s1; /* structure copy */
225 SHA_Bytes(&s, intermediate, 4);
226 SHA_Bytes(&s, blk, len);
227 SHA_Final(&s, intermediate);
228 s = *s2; /* structure copy */
229 SHA_Bytes(&s, intermediate, 20);
233 static void sha1_generate(unsigned char *blk, int len, unsigned long seq) {
235 debug(("Gen HMAC on block len=%d seq=%d:\r\n", len, seq));
236 for (i=0; i<len; i++) debug((" %02X", blk[i]));
239 sha1_do_hmac(&sha1_cs_mac_s1, &sha1_cs_mac_s2, blk, len, seq, blk+len);
241 debug(("We compute HMAC as:\r\n"));
242 for (i=0; i<20; i++) debug((" %02X", blk[len+i]));
247 static int sha1_verify(unsigned char *blk, int len, unsigned long seq) {
248 unsigned char correct[20];
250 debug(("HMAC on block len=%d seq=%d:\r\n", len, seq));
251 for (i=0; i<len; i++) debug((" %02X", blk[i]));
254 sha1_do_hmac(&sha1_sc_mac_s1, &sha1_sc_mac_s2, blk, len, seq, correct);
256 debug(("We compute HMAC as:\r\n"));
257 for (i=0; i<20; i++) debug((" %02X", correct[i]));
260 return !memcmp(correct, blk+len, 20);
263 struct ssh_mac ssh_sha1 = {
264 sha1_cskey, sha1_sckey,