| 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 | } |