374330e2 |
1 | /* |
2e85c969 |
2 | * SHA1 hash algorithm. Used in SSH-2 as a MAC, and the transform is |
e5574168 |
3 | * also used as a `stirring' function for the PuTTY random number |
4 | * pool. Implemented directly from the specification by Simon |
5 | * Tatham. |
374330e2 |
6 | */ |
7 | |
8 | #include "ssh.h" |
9 | |
e5574168 |
10 | /* ---------------------------------------------------------------------- |
11 | * Core SHA algorithm: processes 16-word blocks into a message digest. |
12 | */ |
13 | |
14 | #define rol(x,y) ( ((x) << (y)) | (((uint32)x) >> (32-y)) ) |
15 | |
d5696ae5 |
16 | static void SHA_Core_Init(uint32 h[5]) |
32874aea |
17 | { |
e5574168 |
18 | h[0] = 0x67452301; |
19 | h[1] = 0xefcdab89; |
20 | h[2] = 0x98badcfe; |
21 | h[3] = 0x10325476; |
22 | h[4] = 0xc3d2e1f0; |
23 | } |
e9483e66 |
24 | |
32874aea |
25 | void SHATransform(word32 * digest, word32 * block) |
26 | { |
e9483e66 |
27 | word32 w[80]; |
32874aea |
28 | word32 a, b, c, d, e; |
e9483e66 |
29 | int t; |
30 | |
d2be8a43 |
31 | #ifdef RANDOM_DIAGNOSTICS |
32 | { |
33 | extern int random_diagnostics; |
34 | if (random_diagnostics) { |
35 | int i; |
36 | printf("SHATransform:"); |
37 | for (i = 0; i < 5; i++) |
38 | printf(" %08x", digest[i]); |
39 | printf(" +"); |
40 | for (i = 0; i < 16; i++) |
41 | printf(" %08x", block[i]); |
42 | } |
43 | } |
44 | #endif |
45 | |
e9483e66 |
46 | for (t = 0; t < 16; t++) |
32874aea |
47 | w[t] = block[t]; |
e9483e66 |
48 | |
49 | for (t = 16; t < 80; t++) { |
32874aea |
50 | word32 tmp = w[t - 3] ^ w[t - 8] ^ w[t - 14] ^ w[t - 16]; |
51 | w[t] = rol(tmp, 1); |
e9483e66 |
52 | } |
53 | |
54 | a = digest[0]; |
55 | b = digest[1]; |
56 | c = digest[2]; |
57 | d = digest[3]; |
58 | e = digest[4]; |
59 | |
60 | for (t = 0; t < 20; t++) { |
32874aea |
61 | word32 tmp = |
62 | rol(a, 5) + ((b & c) | (d & ~b)) + e + w[t] + 0x5a827999; |
63 | e = d; |
64 | d = c; |
65 | c = rol(b, 30); |
66 | b = a; |
67 | a = tmp; |
e9483e66 |
68 | } |
69 | for (t = 20; t < 40; t++) { |
32874aea |
70 | word32 tmp = rol(a, 5) + (b ^ c ^ d) + e + w[t] + 0x6ed9eba1; |
71 | e = d; |
72 | d = c; |
73 | c = rol(b, 30); |
74 | b = a; |
75 | a = tmp; |
e9483e66 |
76 | } |
77 | for (t = 40; t < 60; t++) { |
32874aea |
78 | word32 tmp = rol(a, |
79 | 5) + ((b & c) | (b & d) | (c & d)) + e + w[t] + |
80 | 0x8f1bbcdc; |
81 | e = d; |
82 | d = c; |
83 | c = rol(b, 30); |
84 | b = a; |
85 | a = tmp; |
e9483e66 |
86 | } |
87 | for (t = 60; t < 80; t++) { |
32874aea |
88 | word32 tmp = rol(a, 5) + (b ^ c ^ d) + e + w[t] + 0xca62c1d6; |
89 | e = d; |
90 | d = c; |
91 | c = rol(b, 30); |
92 | b = a; |
93 | a = tmp; |
e9483e66 |
94 | } |
95 | |
96 | digest[0] += a; |
97 | digest[1] += b; |
98 | digest[2] += c; |
99 | digest[3] += d; |
100 | digest[4] += e; |
d2be8a43 |
101 | |
102 | #ifdef RANDOM_DIAGNOSTICS |
103 | { |
104 | extern int random_diagnostics; |
105 | if (random_diagnostics) { |
106 | int i; |
107 | printf(" ="); |
108 | for (i = 0; i < 5; i++) |
109 | printf(" %08x", digest[i]); |
110 | printf("\n"); |
111 | } |
112 | } |
113 | #endif |
374330e2 |
114 | } |
e5574168 |
115 | |
116 | /* ---------------------------------------------------------------------- |
117 | * Outer SHA algorithm: take an arbitrary length byte string, |
118 | * convert it into 16-word blocks with the prescribed padding at |
119 | * the end, and pass those blocks to the core SHA algorithm. |
120 | */ |
121 | |
32874aea |
122 | void SHA_Init(SHA_State * s) |
123 | { |
e5574168 |
124 | SHA_Core_Init(s->h); |
125 | s->blkused = 0; |
126 | s->lenhi = s->lenlo = 0; |
127 | } |
128 | |
42466758 |
129 | void SHA_Bytes(SHA_State * s, const void *p, int len) |
32874aea |
130 | { |
42466758 |
131 | const unsigned char *q = (const unsigned char *) p; |
e5574168 |
132 | uint32 wordblock[16]; |
133 | uint32 lenw = len; |
134 | int i; |
135 | |
136 | /* |
137 | * Update the length field. |
138 | */ |
139 | s->lenlo += lenw; |
140 | s->lenhi += (s->lenlo < lenw); |
141 | |
32874aea |
142 | if (s->blkused && s->blkused + len < 64) { |
143 | /* |
144 | * Trivial case: just add to the block. |
145 | */ |
146 | memcpy(s->block + s->blkused, q, len); |
147 | s->blkused += len; |
e5574168 |
148 | } else { |
32874aea |
149 | /* |
150 | * We must complete and process at least one block. |
151 | */ |
152 | while (s->blkused + len >= 64) { |
153 | memcpy(s->block + s->blkused, q, 64 - s->blkused); |
154 | q += 64 - s->blkused; |
155 | len -= 64 - s->blkused; |
156 | /* Now process the block. Gather bytes big-endian into words */ |
157 | for (i = 0; i < 16; i++) { |
158 | wordblock[i] = |
159 | (((uint32) s->block[i * 4 + 0]) << 24) | |
160 | (((uint32) s->block[i * 4 + 1]) << 16) | |
161 | (((uint32) s->block[i * 4 + 2]) << 8) | |
162 | (((uint32) s->block[i * 4 + 3]) << 0); |
163 | } |
164 | SHATransform(s->h, wordblock); |
165 | s->blkused = 0; |
166 | } |
167 | memcpy(s->block, q, len); |
168 | s->blkused = len; |
e5574168 |
169 | } |
170 | } |
171 | |
32874aea |
172 | void SHA_Final(SHA_State * s, unsigned char *output) |
173 | { |
e5574168 |
174 | int i; |
175 | int pad; |
176 | unsigned char c[64]; |
177 | uint32 lenhi, lenlo; |
178 | |
179 | if (s->blkused >= 56) |
32874aea |
180 | pad = 56 + 64 - s->blkused; |
e5574168 |
181 | else |
32874aea |
182 | pad = 56 - s->blkused; |
e5574168 |
183 | |
32874aea |
184 | lenhi = (s->lenhi << 3) | (s->lenlo >> (32 - 3)); |
e5574168 |
185 | lenlo = (s->lenlo << 3); |
186 | |
187 | memset(c, 0, pad); |
188 | c[0] = 0x80; |
189 | SHA_Bytes(s, &c, pad); |
190 | |
191 | c[0] = (lenhi >> 24) & 0xFF; |
192 | c[1] = (lenhi >> 16) & 0xFF; |
32874aea |
193 | c[2] = (lenhi >> 8) & 0xFF; |
194 | c[3] = (lenhi >> 0) & 0xFF; |
e5574168 |
195 | c[4] = (lenlo >> 24) & 0xFF; |
196 | c[5] = (lenlo >> 16) & 0xFF; |
32874aea |
197 | c[6] = (lenlo >> 8) & 0xFF; |
198 | c[7] = (lenlo >> 0) & 0xFF; |
e5574168 |
199 | |
200 | SHA_Bytes(s, &c, 8); |
201 | |
202 | for (i = 0; i < 5; i++) { |
32874aea |
203 | output[i * 4] = (s->h[i] >> 24) & 0xFF; |
204 | output[i * 4 + 1] = (s->h[i] >> 16) & 0xFF; |
205 | output[i * 4 + 2] = (s->h[i] >> 8) & 0xFF; |
206 | output[i * 4 + 3] = (s->h[i]) & 0xFF; |
e5574168 |
207 | } |
208 | } |
209 | |
42466758 |
210 | void SHA_Simple(const void *p, int len, unsigned char *output) |
32874aea |
211 | { |
e5574168 |
212 | SHA_State s; |
213 | |
214 | SHA_Init(&s); |
215 | SHA_Bytes(&s, p, len); |
216 | SHA_Final(&s, output); |
217 | } |
218 | |
b672f405 |
219 | /* |
220 | * Thin abstraction for things where hashes are pluggable. |
221 | */ |
222 | |
223 | static void *sha1_init(void) |
224 | { |
225 | SHA_State *s; |
226 | |
227 | s = snew(SHA_State); |
228 | SHA_Init(s); |
229 | return s; |
230 | } |
231 | |
232 | static void sha1_bytes(void *handle, void *p, int len) |
233 | { |
234 | SHA_State *s = handle; |
235 | |
236 | SHA_Bytes(s, p, len); |
237 | } |
238 | |
239 | static void sha1_final(void *handle, unsigned char *output) |
240 | { |
241 | SHA_State *s = handle; |
242 | |
243 | SHA_Final(s, output); |
244 | sfree(s); |
245 | } |
246 | |
247 | const struct ssh_hash ssh_sha1 = { |
c6daaa1a |
248 | sha1_init, sha1_bytes, sha1_final, 20, "SHA-1" |
b672f405 |
249 | }; |
250 | |
e5574168 |
251 | /* ---------------------------------------------------------------------- |
252 | * The above is the SHA-1 algorithm itself. Now we implement the |
253 | * HMAC wrapper on it. |
254 | */ |
255 | |
e0e1a00d |
256 | static void *sha1_make_context(void) |
257 | { |
9916cc1e |
258 | return snewn(3, SHA_State); |
e0e1a00d |
259 | } |
260 | |
261 | static void sha1_free_context(void *handle) |
262 | { |
263 | sfree(handle); |
264 | } |
e5574168 |
265 | |
e0e1a00d |
266 | static void sha1_key_internal(void *handle, unsigned char *key, int len) |
32874aea |
267 | { |
e0e1a00d |
268 | SHA_State *keys = (SHA_State *)handle; |
e5574168 |
269 | unsigned char foo[64]; |
270 | int i; |
271 | |
272 | memset(foo, 0x36, 64); |
273 | for (i = 0; i < len && i < 64; i++) |
32874aea |
274 | foo[i] ^= key[i]; |
e0e1a00d |
275 | SHA_Init(&keys[0]); |
276 | SHA_Bytes(&keys[0], foo, 64); |
e5574168 |
277 | |
278 | memset(foo, 0x5C, 64); |
279 | for (i = 0; i < len && i < 64; i++) |
32874aea |
280 | foo[i] ^= key[i]; |
e0e1a00d |
281 | SHA_Init(&keys[1]); |
282 | SHA_Bytes(&keys[1], foo, 64); |
e5574168 |
283 | |
dfb88efd |
284 | smemclr(foo, 64); /* burn the evidence */ |
e5574168 |
285 | } |
286 | |
e0e1a00d |
287 | static void sha1_key(void *handle, unsigned char *key) |
32874aea |
288 | { |
e0e1a00d |
289 | sha1_key_internal(handle, key, 20); |
7591b9ff |
290 | } |
291 | |
e0e1a00d |
292 | static void sha1_key_buggy(void *handle, unsigned char *key) |
32874aea |
293 | { |
e0e1a00d |
294 | sha1_key_internal(handle, key, 16); |
7591b9ff |
295 | } |
296 | |
9916cc1e |
297 | static void hmacsha1_start(void *handle) |
298 | { |
299 | SHA_State *keys = (SHA_State *)handle; |
300 | |
301 | keys[2] = keys[0]; /* structure copy */ |
302 | } |
303 | |
304 | static void hmacsha1_bytes(void *handle, unsigned char const *blk, int len) |
305 | { |
306 | SHA_State *keys = (SHA_State *)handle; |
307 | SHA_Bytes(&keys[2], (void *)blk, len); |
308 | } |
309 | |
310 | static void hmacsha1_genresult(void *handle, unsigned char *hmac) |
32874aea |
311 | { |
e0e1a00d |
312 | SHA_State *keys = (SHA_State *)handle; |
e5574168 |
313 | SHA_State s; |
314 | unsigned char intermediate[20]; |
315 | |
9916cc1e |
316 | s = keys[2]; /* structure copy */ |
e5574168 |
317 | SHA_Final(&s, intermediate); |
e0e1a00d |
318 | s = keys[1]; /* structure copy */ |
e5574168 |
319 | SHA_Bytes(&s, intermediate, 20); |
320 | SHA_Final(&s, hmac); |
321 | } |
322 | |
9916cc1e |
323 | static void sha1_do_hmac(void *handle, unsigned char *blk, int len, |
324 | unsigned long seq, unsigned char *hmac) |
325 | { |
326 | unsigned char seqbuf[4]; |
327 | |
bb4a3bb6 |
328 | PUT_32BIT_MSB_FIRST(seqbuf, seq); |
9916cc1e |
329 | hmacsha1_start(handle); |
330 | hmacsha1_bytes(handle, seqbuf, 4); |
331 | hmacsha1_bytes(handle, blk, len); |
332 | hmacsha1_genresult(handle, hmac); |
333 | } |
334 | |
e0e1a00d |
335 | static void sha1_generate(void *handle, unsigned char *blk, int len, |
336 | unsigned long seq) |
32874aea |
337 | { |
e0e1a00d |
338 | sha1_do_hmac(handle, blk, len, seq, blk + len); |
e5574168 |
339 | } |
340 | |
9916cc1e |
341 | static int hmacsha1_verresult(void *handle, unsigned char const *hmac) |
342 | { |
343 | unsigned char correct[20]; |
344 | hmacsha1_genresult(handle, correct); |
345 | return !memcmp(correct, hmac, 20); |
346 | } |
347 | |
e0e1a00d |
348 | static int sha1_verify(void *handle, unsigned char *blk, int len, |
349 | unsigned long seq) |
32874aea |
350 | { |
e5574168 |
351 | unsigned char correct[20]; |
e0e1a00d |
352 | sha1_do_hmac(handle, blk, len, seq, correct); |
32874aea |
353 | return !memcmp(correct, blk + len, 20); |
e5574168 |
354 | } |
355 | |
9916cc1e |
356 | static void hmacsha1_96_genresult(void *handle, unsigned char *hmac) |
357 | { |
358 | unsigned char full[20]; |
359 | hmacsha1_genresult(handle, full); |
360 | memcpy(hmac, full, 12); |
361 | } |
362 | |
6668a75e |
363 | static void sha1_96_generate(void *handle, unsigned char *blk, int len, |
364 | unsigned long seq) |
365 | { |
366 | unsigned char full[20]; |
367 | sha1_do_hmac(handle, blk, len, seq, full); |
368 | memcpy(blk + len, full, 12); |
369 | } |
370 | |
9916cc1e |
371 | static int hmacsha1_96_verresult(void *handle, unsigned char const *hmac) |
372 | { |
373 | unsigned char correct[20]; |
374 | hmacsha1_genresult(handle, correct); |
375 | return !memcmp(correct, hmac, 12); |
376 | } |
377 | |
6668a75e |
378 | static int sha1_96_verify(void *handle, unsigned char *blk, int len, |
379 | unsigned long seq) |
380 | { |
381 | unsigned char correct[20]; |
382 | sha1_do_hmac(handle, blk, len, seq, correct); |
383 | return !memcmp(correct, blk + len, 12); |
384 | } |
385 | |
5c72ca61 |
386 | void hmac_sha1_simple(void *key, int keylen, void *data, int datalen, |
387 | unsigned char *output) { |
e0e1a00d |
388 | SHA_State states[2]; |
5c72ca61 |
389 | unsigned char intermediate[20]; |
390 | |
e0e1a00d |
391 | sha1_key_internal(states, key, keylen); |
392 | SHA_Bytes(&states[0], data, datalen); |
393 | SHA_Final(&states[0], intermediate); |
5c72ca61 |
394 | |
e0e1a00d |
395 | SHA_Bytes(&states[1], intermediate, 20); |
396 | SHA_Final(&states[1], output); |
5c72ca61 |
397 | } |
398 | |
1993f323 |
399 | const struct ssh_mac ssh_hmac_sha1 = { |
e0e1a00d |
400 | sha1_make_context, sha1_free_context, sha1_key, |
401 | sha1_generate, sha1_verify, |
9916cc1e |
402 | hmacsha1_start, hmacsha1_bytes, hmacsha1_genresult, hmacsha1_verresult, |
e5574168 |
403 | "hmac-sha1", |
6c135243 |
404 | 20, |
405 | "HMAC-SHA1" |
e5574168 |
406 | }; |
7591b9ff |
407 | |
6668a75e |
408 | const struct ssh_mac ssh_hmac_sha1_96 = { |
409 | sha1_make_context, sha1_free_context, sha1_key, |
410 | sha1_96_generate, sha1_96_verify, |
9916cc1e |
411 | hmacsha1_start, hmacsha1_bytes, |
412 | hmacsha1_96_genresult, hmacsha1_96_verresult, |
6668a75e |
413 | "hmac-sha1-96", |
414 | 12, |
415 | "HMAC-SHA1-96" |
416 | }; |
417 | |
1993f323 |
418 | const struct ssh_mac ssh_hmac_sha1_buggy = { |
e0e1a00d |
419 | sha1_make_context, sha1_free_context, sha1_key_buggy, |
420 | sha1_generate, sha1_verify, |
9916cc1e |
421 | hmacsha1_start, hmacsha1_bytes, hmacsha1_genresult, hmacsha1_verresult, |
7591b9ff |
422 | "hmac-sha1", |
6c135243 |
423 | 20, |
424 | "bug-compatible HMAC-SHA1" |
7591b9ff |
425 | }; |
6668a75e |
426 | |
427 | const struct ssh_mac ssh_hmac_sha1_96_buggy = { |
428 | sha1_make_context, sha1_free_context, sha1_key_buggy, |
429 | sha1_96_generate, sha1_96_verify, |
9916cc1e |
430 | hmacsha1_start, hmacsha1_bytes, |
431 | hmacsha1_96_genresult, hmacsha1_96_verresult, |
6668a75e |
432 | "hmac-sha1-96", |
433 | 12, |
434 | "bug-compatible HMAC-SHA1-96" |
435 | }; |