8f203108 |
1 | #define _WIN32_WINNT 0x0400 |
2 | #include <windows.h> |
3 | #include <stdio.h> |
4 | #include <stdlib.h> |
5 | #include <wincrypt.h> |
6 | #include "ssh.h" |
7 | |
8 | void fatalbox(char *fmt, ...); |
9 | |
10 | static HCRYPTKEY create_des_key(unsigned char *key); |
11 | |
12 | |
13 | HCRYPTPROV hCryptProv; |
14 | HCRYPTKEY hDESKey[2][3] = {{0,0,0},{0,0,0}}; /* global for now */ |
15 | |
16 | |
17 | /* use Microsoft Enhanced Cryptographic Service Provider */ |
18 | #define CSP MS_ENHANCED_PROV |
19 | |
20 | |
21 | static BYTE PrivateKeyWithExponentOfOne[] = |
22 | { |
23 | 0x07, 0x02, 0x00, 0x00, 0x00, 0xA4, 0x00, 0x00, |
24 | 0x52, 0x53, 0x41, 0x32, 0x00, 0x02, 0x00, 0x00, |
25 | 0x01, 0x00, 0x00, 0x00, 0xAB, 0xEF, 0xFA, 0xC6, |
26 | 0x7D, 0xE8, 0xDE, 0xFB, 0x68, 0x38, 0x09, 0x92, |
27 | 0xD9, 0x42, 0x7E, 0x6B, 0x89, 0x9E, 0x21, 0xD7, |
28 | 0x52, 0x1C, 0x99, 0x3C, 0x17, 0x48, 0x4E, 0x3A, |
29 | 0x44, 0x02, 0xF2, 0xFA, 0x74, 0x57, 0xDA, 0xE4, |
30 | 0xD3, 0xC0, 0x35, 0x67, 0xFA, 0x6E, 0xDF, 0x78, |
31 | 0x4C, 0x75, 0x35, 0x1C, 0xA0, 0x74, 0x49, 0xE3, |
32 | 0x20, 0x13, 0x71, 0x35, 0x65, 0xDF, 0x12, 0x20, |
33 | 0xF5, 0xF5, 0xF5, 0xC1, 0xED, 0x5C, 0x91, 0x36, |
34 | 0x75, 0xB0, 0xA9, 0x9C, 0x04, 0xDB, 0x0C, 0x8C, |
35 | 0xBF, 0x99, 0x75, 0x13, 0x7E, 0x87, 0x80, 0x4B, |
36 | 0x71, 0x94, 0xB8, 0x00, 0xA0, 0x7D, 0xB7, 0x53, |
37 | 0xDD, 0x20, 0x63, 0xEE, 0xF7, 0x83, 0x41, 0xFE, |
38 | 0x16, 0xA7, 0x6E, 0xDF, 0x21, 0x7D, 0x76, 0xC0, |
39 | 0x85, 0xD5, 0x65, 0x7F, 0x00, 0x23, 0x57, 0x45, |
40 | 0x52, 0x02, 0x9D, 0xEA, 0x69, 0xAC, 0x1F, 0xFD, |
41 | 0x3F, 0x8C, 0x4A, 0xD0, |
42 | |
43 | 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
44 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
45 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
46 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
47 | |
48 | 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
49 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
50 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
51 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
52 | |
53 | 0x64, 0xD5, 0xAA, 0xB1, |
54 | 0xA6, 0x03, 0x18, 0x92, 0x03, 0xAA, 0x31, 0x2E, |
55 | 0x48, 0x4B, 0x65, 0x20, 0x99, 0xCD, 0xC6, 0x0C, |
56 | 0x15, 0x0C, 0xBF, 0x3E, 0xFF, 0x78, 0x95, 0x67, |
57 | 0xB1, 0x74, 0x5B, 0x60, |
58 | |
59 | 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
60 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
61 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
62 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
63 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
64 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
65 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
66 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
67 | }; |
68 | |
69 | |
70 | |
71 | /* ---------------------------------------------------------* |
72 | * Utility functions * |
73 | * ---------------------------------------------------------*/ |
74 | |
75 | |
76 | int crypto_startup() { |
77 | if(CryptAcquireContext(&hCryptProv, "Putty", CSP, PROV_RSA_FULL, |
78 | CRYPT_NEWKEYSET) == 0) { |
79 | if(GetLastError() == NTE_EXISTS) { |
80 | if(CryptAcquireContext(&hCryptProv, "Putty", CSP, |
81 | PROV_RSA_FULL, 0) == 0) { |
82 | return FALSE; /* failed to acquire context - probably |
83 | * don't have high encryption installed! */ |
84 | } |
85 | } else |
86 | return FALSE; /* failed to acquire context - probably |
87 | * don't have high encryption installed! */ |
88 | } |
89 | return TRUE; |
90 | } |
91 | |
92 | |
93 | void crypto_wrapup() { |
94 | int i, j; |
95 | for(i=0; i<2; i++) { |
96 | for(j=0; j<3; j++) { |
97 | if(hDESKey[i][j]) |
98 | CryptDestroyKey(hDESKey[i][j]); |
99 | hDESKey[i][j] = 0; |
100 | } |
101 | } |
102 | if(hCryptProv) |
103 | CryptReleaseContext(hCryptProv, 0); |
104 | hCryptProv = 0; |
105 | } |
106 | |
107 | |
108 | /* ---------------------------------------------------------* |
109 | * Random number functions * |
110 | * ---------------------------------------------------------*/ |
111 | |
112 | int random_byte(void) { |
113 | unsigned char b; |
114 | if(!CryptGenRandom(hCryptProv, 1, &b)) |
115 | fatalbox("random number generator failure!"); |
116 | return b; |
117 | } |
118 | |
119 | void random_add_noise(void *noise, int length) { |
120 | /* do nothing */ |
121 | } |
122 | void random_init(void) { |
123 | /* do nothing */ |
124 | } |
125 | void random_get_savedata(void **data, int *len) { |
126 | /* do nothing */ |
127 | } |
128 | void noise_get_heavy(void (*func) (void *, int)) { |
129 | /* do nothing */ |
130 | } |
131 | void noise_get_light(void (*func) (void *, int)) { |
132 | /* do nothing */ |
133 | } |
134 | void noise_ultralight(DWORD data) { |
135 | /* do nothing */ |
136 | } |
137 | void random_save_seed(void) { |
138 | /* do nothing */ |
139 | } |
140 | |
141 | |
142 | /* ---------------------------------------------------------* |
143 | * MD5 hash functions * |
144 | * ---------------------------------------------------------*/ |
145 | |
146 | |
147 | void MD5Init(struct MD5Context *ctx) { |
148 | if(!CryptCreateHash(hCryptProv, CALG_MD5, 0, 0, &ctx->hHash)) |
149 | fatalbox("Error during CryptBeginHash!\n"); |
150 | } |
151 | |
152 | |
153 | void MD5Update(struct MD5Context *ctx, |
154 | unsigned char const *buf, unsigned len) { |
155 | if(CryptHashData(ctx->hHash, buf, len, 0) == 0) |
156 | fatalbox("Error during CryptHashSessionKey!\n"); |
157 | } |
158 | |
159 | |
160 | void MD5Final(unsigned char digest[16], struct MD5Context *ctx) { |
161 | DWORD cb = 16; |
162 | if(CryptGetHashParam(ctx->hHash, HP_HASHVAL, digest, &cb, 0) == 0) |
163 | fatalbox("Error during CryptGetHashParam!\n"); |
164 | if(ctx->hHash) |
165 | CryptDestroyHash(ctx->hHash); |
166 | ctx->hHash = 0; |
167 | } |
168 | |
169 | |
170 | /* ---------------------------------------------------------* |
171 | * RSA public key functions * |
172 | * ---------------------------------------------------------*/ |
173 | |
174 | int makekey(unsigned char *data, struct RSAKey *result, |
175 | unsigned char **keystr) { |
176 | |
177 | unsigned char *p = data; |
178 | int i; |
179 | int w, b; |
180 | |
181 | /* get size (bits) of modulus */ |
182 | result->bits = 0; |
183 | for(i=0; i<4; i++) |
184 | result->bits = (result->bits << 8) + *p++; |
185 | |
186 | /* get size (bits) of public exponent */ |
187 | w = 0; |
188 | for (i=0; i<2; i++) |
189 | w = (w << 8) + *p++; |
190 | b = (w+7)/8; /* bits -> bytes */ |
191 | |
192 | /* convert exponent to DWORD */ |
193 | result->exponent = 0; |
194 | for (i=0; i<b; i++) |
195 | result->exponent = (result->exponent << 8) + *p++; |
196 | |
197 | /* get size (bits) of modulus */ |
198 | w = 0; |
199 | for (i=0; i<2; i++) |
200 | w = (w << 8) + *p++; |
201 | result->bytes = b = (w+7)/8; /* bits -> bytes */ |
202 | |
203 | /* allocate buffer for modulus & copy it */ |
204 | result->modulus = malloc(b); |
205 | memcpy(result->modulus, p, b); |
206 | |
207 | /* update callers pointer */ |
208 | if (keystr) *keystr = p; /* point at key string, second time */ |
209 | |
210 | return (p - data) + b; |
211 | } |
212 | |
213 | |
214 | void rsaencrypt(unsigned char *data, int length, struct RSAKey *rsakey) { |
215 | |
216 | int i; |
217 | unsigned char *pKeybuf, *pKeyin; |
218 | HCRYPTKEY hRsaKey; |
219 | PUBLICKEYSTRUC *pBlob; |
220 | RSAPUBKEY *pRPK; |
221 | unsigned char *buf; |
222 | DWORD dlen; |
223 | DWORD bufsize; |
224 | |
225 | /* allocate buffer for public key blob */ |
226 | if((pBlob = malloc(sizeof(PUBLICKEYSTRUC) + sizeof(RSAPUBKEY) + |
227 | rsakey->bytes)) == NULL) |
228 | fatalbox("Out of memory"); |
229 | |
230 | /* allocate buffer for message encryption block */ |
231 | bufsize = (length + rsakey->bytes) << 1; |
232 | if((buf = malloc(bufsize)) == NULL) |
233 | fatalbox("Out of memory"); |
234 | |
235 | /* construct public key blob from host public key */ |
236 | pKeybuf = ((unsigned char*)pBlob) + sizeof(PUBLICKEYSTRUC) + |
237 | sizeof(RSAPUBKEY); |
238 | pKeyin = ((unsigned char*)rsakey->modulus); |
239 | /* change big endian to little endian */ |
240 | for(i=0; i<rsakey->bytes; i++) |
241 | pKeybuf[i] = pKeyin[rsakey->bytes-i-1]; |
242 | pBlob->bType = PUBLICKEYBLOB; |
243 | pBlob->bVersion = 0x02; |
244 | pBlob->reserved = 0; |
245 | pBlob->aiKeyAlg = CALG_RSA_KEYX; |
246 | pRPK = (RSAPUBKEY*)(((unsigned char*)pBlob) + sizeof(PUBLICKEYSTRUC)); |
247 | pRPK->magic = 0x31415352; /* "RSA1" */ |
248 | pRPK->bitlen = rsakey->bits; |
249 | pRPK->pubexp = rsakey->exponent; |
250 | |
251 | /* import public key blob into key container */ |
252 | if(CryptImportKey(hCryptProv, (void*)pBlob, |
253 | sizeof(PUBLICKEYSTRUC)+sizeof(RSAPUBKEY)+rsakey->bytes, |
254 | 0, 0, &hRsaKey) == 0) |
255 | fatalbox("Error importing RSA key!"); |
256 | |
257 | /* copy message into buffer */ |
258 | memcpy(buf, data, length); |
259 | dlen = length; |
260 | |
261 | /* using host public key, encrypt the message */ |
262 | if(CryptEncrypt(hRsaKey, 0, TRUE, 0, buf, &dlen, bufsize) == 0) |
263 | fatalbox("Error encrypting using RSA key!"); |
264 | |
265 | /* |
266 | * For some strange reason, Microsoft CryptEncrypt using public |
267 | * key, returns the cyphertext in backwards (little endian) |
268 | * order, so reverse it! |
269 | */ |
270 | for(i = 0; i < (int)dlen; i++) |
271 | data[i] = buf[dlen - i - 1]; /* make it big endian */ |
272 | |
273 | CryptDestroyKey(hRsaKey); |
274 | free(buf); |
275 | free(pBlob); |
276 | |
277 | } |
278 | |
279 | |
280 | int rsastr_len(struct RSAKey *key) { |
281 | return 2 * (sizeof(DWORD) + key->bytes) + 10; |
282 | } |
283 | |
284 | |
285 | void rsastr_fmt(char *str, struct RSAKey *key) { |
286 | |
287 | int len = 0, i; |
288 | |
289 | sprintf(str+len, "%04x", key->exponent); |
290 | len += strlen(str+len); |
291 | |
292 | str[len++] = '/'; |
293 | for (i=1; i<key->bytes; i++) { |
294 | sprintf(str+len, "%02x", key->modulus[i]); |
295 | len += strlen(str+len); |
296 | } |
297 | str[len] = '\0'; |
298 | } |
299 | |
300 | |
301 | |
302 | /* ---------------------------------------------------------* |
303 | * DES encryption / decryption functions * |
304 | * ---------------------------------------------------------*/ |
305 | |
306 | |
307 | void des3_sesskey(unsigned char *key) { |
308 | int i, j; |
309 | for(i = 0; i < 2; i++) { |
310 | for(j = 0; j < 3; j++) { |
311 | hDESKey[i][j] = create_des_key(key + (j * 8)); |
312 | } |
313 | } |
314 | } |
315 | |
316 | |
317 | void des3_encrypt_blk(unsigned char *blk, int len) { |
318 | |
319 | DWORD dlen; |
320 | dlen = len; |
321 | |
322 | if(CryptEncrypt(hDESKey[0][0], 0, FALSE, 0, blk, &dlen, len + 8) == 0) |
323 | fatalbox("Error encrypting block!\n"); |
324 | if(CryptDecrypt(hDESKey[0][1], 0, FALSE, 0, blk, &dlen) == 0) |
325 | fatalbox("Error encrypting block!\n"); |
326 | if(CryptEncrypt(hDESKey[0][2], 0, FALSE, 0, blk, &dlen, len + 8) == 0) |
327 | fatalbox("Error encrypting block!\n"); |
328 | } |
329 | |
330 | |
331 | void des3_decrypt_blk(unsigned char *blk, int len) { |
332 | DWORD dlen; |
333 | dlen = len; |
334 | |
335 | if(CryptDecrypt(hDESKey[1][2], 0, FALSE, 0, blk, &dlen) == 0) |
336 | fatalbox("Error decrypting block!\n"); |
337 | if(CryptEncrypt(hDESKey[1][1], 0, FALSE, 0, blk, &dlen, len + 8) == 0) |
338 | fatalbox("Error decrypting block!\n"); |
339 | if(CryptDecrypt(hDESKey[1][0], 0, FALSE, 0, blk, &dlen) == 0) |
340 | fatalbox("Error decrypting block!\n"); |
341 | } |
342 | |
343 | |
344 | struct ssh_cipher ssh_3des = { |
345 | des3_sesskey, |
346 | des3_encrypt_blk, |
347 | des3_decrypt_blk |
348 | }; |
349 | |
350 | |
351 | void des_sesskey(unsigned char *key) { |
352 | int i; |
353 | for(i = 0; i < 2; i++) { |
354 | hDESKey[i][0] = create_des_key(key); |
355 | } |
356 | } |
357 | |
358 | |
359 | void des_encrypt_blk(unsigned char *blk, int len) { |
360 | DWORD dlen; |
361 | dlen = len; |
362 | if(CryptEncrypt(hDESKey[0][0], 0, FALSE, 0, blk, &dlen, len + 8) == 0) |
363 | fatalbox("Error encrypting block!\n"); |
364 | } |
365 | |
366 | |
367 | void des_decrypt_blk(unsigned char *blk, int len) { |
368 | DWORD dlen; |
369 | dlen = len; |
370 | if(CryptDecrypt(hDESKey[1][0], 0, FALSE, 0, blk, &dlen) == 0) |
371 | fatalbox("Error decrypting block!\n"); |
372 | } |
373 | |
374 | struct ssh_cipher ssh_des = { |
375 | des_sesskey, |
376 | des_encrypt_blk, |
377 | des_decrypt_blk |
378 | }; |
379 | |
380 | |
381 | static HCRYPTKEY create_des_key(unsigned char *key) { |
382 | |
383 | HCRYPTKEY hSessionKey, hPrivateKey; |
384 | DWORD dlen = 8; |
385 | BLOBHEADER *pbh; |
386 | char buf[sizeof(BLOBHEADER) + sizeof(ALG_ID) + 256]; |
387 | |
388 | /* |
389 | * Need special private key to encrypt session key so we can |
390 | * import session key, since only encrypted session keys can be |
391 | * imported |
392 | */ |
393 | if(CryptImportKey(hCryptProv, PrivateKeyWithExponentOfOne, |
394 | sizeof(PrivateKeyWithExponentOfOne), |
395 | 0, 0, &hPrivateKey) == 0) |
396 | return 0; |
397 | |
398 | /* now encrypt session key using special private key */ |
399 | memcpy(buf + sizeof(BLOBHEADER) + sizeof(ALG_ID), key, 8); |
400 | if(CryptEncrypt(hPrivateKey, 0, TRUE, 0, |
401 | buf + sizeof(BLOBHEADER) + sizeof(ALG_ID), |
402 | &dlen, 256) == 0) |
403 | return 0; |
404 | |
405 | /* build session key blob */ |
406 | pbh = (BLOBHEADER*)buf; |
407 | pbh->bType = SIMPLEBLOB; |
408 | pbh->bVersion = 0x02; |
409 | pbh->reserved = 0; |
410 | pbh->aiKeyAlg = CALG_DES; |
411 | *((ALG_ID*)(buf+sizeof(BLOBHEADER))) = CALG_RSA_KEYX; |
412 | |
413 | /* import session key into key container */ |
414 | if(CryptImportKey(hCryptProv, buf, |
415 | dlen + sizeof(BLOBHEADER) + sizeof(ALG_ID), |
416 | hPrivateKey, 0, &hSessionKey) == 0) |
417 | return 0; |
418 | |
419 | if(hPrivateKey) |
420 | CryptDestroyKey(hPrivateKey); |
421 | |
422 | return hSessionKey; |
423 | |
424 | } |