git.distorted.org.uk Git - u/mdw/putty/blob - mscrypto.c

   1 #error "This file is no longer part of PuTTY, it will not compile."
   2 #define _WIN32_WINNT 0x0400
   3 #include <windows.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <wincrypt.h>
   7 #include "ssh.h"
   8
   9 void fatalbox(char *fmt, ...);
  10
  11 static HCRYPTKEY create_des_key(unsigned char *key);
  12
  13
  14 HCRYPTPROV hCryptProv;
  15 HCRYPTKEY hDESKey[2][3] = { {0, 0, 0}, {0, 0, 0} };     /* global for now */
  16
  17
  18 /* use Microsoft Enhanced Cryptographic Service Provider */
  19 #define CSP MS_ENHANCED_PROV
  20
  21
  22 static BYTE PrivateKeyWithExponentOfOne[] = {
  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 {
  78     if (CryptAcquireContext(&hCryptProv, "Putty", CSP, PROV_RSA_FULL,
  79                             CRYPT_NEWKEYSET) == 0) {
  80         if (GetLastError() == NTE_EXISTS) {
  81             if (CryptAcquireContext(&hCryptProv, "Putty", CSP,
  82                                     PROV_RSA_FULL, 0) == 0) {
  83                 return FALSE;          /* failed to acquire context - probably
  84                                         * don't have high encryption installed! */
  85             }
  86         } else
  87             return FALSE;              /* failed to acquire context - probably
  88                                         * don't have high encryption installed! */
  89     }
  90     return TRUE;
  91 }
  92
  93
  94 void crypto_wrapup()
  95 {
  96     int i, j;
  97     for (i = 0; i < 2; i++) {
  98         for (j = 0; j < 3; j++) {
  99             if (hDESKey[i][j])
 100                 CryptDestroyKey(hDESKey[i][j]);
 101             hDESKey[i][j] = 0;
 102         }
 103     }
 104     if (hCryptProv)
 105         CryptReleaseContext(hCryptProv, 0);
 106     hCryptProv = 0;
 107 }
 108
 109
 110 /* ---------------------------------------------------------*
 111  * Random number functions                                  *
 112  * ---------------------------------------------------------*/
 113
 114 int random_byte(void)
 115 {
 116     unsigned char b;
 117     if (!CryptGenRandom(hCryptProv, 1, &b))
 118         fatalbox("random number generator failure!");
 119     return b;
 120 }
 121
 122 void random_add_noise(void *noise, int length)
 123 {
 124     /* do nothing */
 125 }
 126 void random_init(void)
 127 {
 128     /* do nothing */
 129 }
 130 void random_get_savedata(void **data, int *len)
 131 {
 132     /* do nothing */
 133 }
 134 void noise_get_heavy(void (*func) (void *, int))
 135 {
 136     /* do nothing */
 137 }
 138 void noise_get_light(void (*func) (void *, int))
 139 {
 140     /* do nothing */
 141 }
 142 void noise_ultralight(DWORD data)
 143 {
 144     /* do nothing */
 145 }
 146 void random_save_seed(void)
 147 {
 148     /* do nothing */
 149 }
 150
 151
 152 /* ---------------------------------------------------------*
 153  * MD5 hash functions                                       *
 154  * ---------------------------------------------------------*/
 155
 156
 157 void MD5Init(struct MD5Context *ctx)
 158 {
 159     if (!CryptCreateHash(hCryptProv, CALG_MD5, 0, 0, &ctx->hHash))
 160         fatalbox("Error during CryptBeginHash!\n");
 161 }
 162
 163
 164 void MD5Update(struct MD5Context *ctx,
 165                unsigned char const *buf, unsigned len)
 166 {
 167     if (CryptHashData(ctx->hHash, buf, len, 0) == 0)
 168         fatalbox("Error during CryptHashSessionKey!\n");
 169 }
 170
 171
 172 void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
 173 {
 174     DWORD cb = 16;
 175     if (CryptGetHashParam(ctx->hHash, HP_HASHVAL, digest, &cb, 0) == 0)
 176         fatalbox("Error during CryptGetHashParam!\n");
 177     if (ctx->hHash)
 178         CryptDestroyHash(ctx->hHash);
 179     ctx->hHash = 0;
 180 }
 181
 182
 183 /* ---------------------------------------------------------*
 184  * RSA public key functions                                 *
 185  * ---------------------------------------------------------*/
 186
 187 int makekey(unsigned char *data, struct RSAKey *result,
 188             unsigned char **keystr)
 189 {
 190
 191     unsigned char *p = data;
 192     int i;
 193     int w, b;
 194
 195     /* get size (bits) of modulus */
 196     result->bits = 0;
 197     for (i = 0; i < 4; i++)
 198         result->bits = (result->bits << 8) + *p++;
 199
 200     /* get size (bits) of public exponent */
 201     w = 0;
 202     for (i = 0; i < 2; i++)
 203         w = (w << 8) + *p++;
 204     b = (w + 7) / 8;                   /* bits -> bytes */
 205
 206     /* convert exponent to DWORD */
 207     result->exponent = 0;
 208     for (i = 0; i < b; i++)
 209         result->exponent = (result->exponent << 8) + *p++;
 210
 211     /* get size (bits) of modulus */
 212     w = 0;
 213     for (i = 0; i < 2; i++)
 214         w = (w << 8) + *p++;
 215     result->bytes = b = (w + 7) / 8;   /* bits -> bytes */
 216
 217     /* allocate buffer for modulus & copy it */
 218     result->modulus = malloc(b);
 219     memcpy(result->modulus, p, b);
 220
 221     /* update callers pointer */
 222     if (keystr)
 223         *keystr = p;                   /* point at key string, second time */
 224
 225     return (p - data) + b;
 226 }
 227
 228
 229 void rsaencrypt(unsigned char *data, int length, struct RSAKey *rsakey)
 230 {
 231
 232     int i;
 233     unsigned char *pKeybuf, *pKeyin;
 234     HCRYPTKEY hRsaKey;
 235     PUBLICKEYSTRUC *pBlob;
 236     RSAPUBKEY *pRPK;
 237     unsigned char *buf;
 238     DWORD dlen;
 239     DWORD bufsize;
 240
 241     /* allocate buffer for public key blob */
 242     if ((pBlob = malloc(sizeof(PUBLICKEYSTRUC) + sizeof(RSAPUBKEY) +
 243                         rsakey->bytes)) == NULL)
 244         fatalbox("Out of memory");
 245
 246     /* allocate buffer for message encryption block */
 247     bufsize = (length + rsakey->bytes) << 1;
 248     if ((buf = malloc(bufsize)) == NULL)
 249         fatalbox("Out of memory");
 250
 251     /* construct public key blob from host public key */
 252     pKeybuf = ((unsigned char *) pBlob) + sizeof(PUBLICKEYSTRUC) +
 253         sizeof(RSAPUBKEY);
 254     pKeyin = ((unsigned char *) rsakey->modulus);
 255     /* change big endian to little endian */
 256     for (i = 0; i < rsakey->bytes; i++)
 257         pKeybuf[i] = pKeyin[rsakey->bytes - i - 1];
 258     pBlob->bType = PUBLICKEYBLOB;
 259     pBlob->bVersion = 0x02;
 260     pBlob->reserved = 0;
 261     pBlob->aiKeyAlg = CALG_RSA_KEYX;
 262     pRPK =
 263         (RSAPUBKEY *) (((unsigned char *) pBlob) + sizeof(PUBLICKEYSTRUC));
 264     pRPK->magic = 0x31415352;          /* "RSA1" */
 265     pRPK->bitlen = rsakey->bits;
 266     pRPK->pubexp = rsakey->exponent;
 267
 268     /* import public key blob into key container */
 269     if (CryptImportKey(hCryptProv, (void *) pBlob,
 270                        sizeof(PUBLICKEYSTRUC) + sizeof(RSAPUBKEY) +
 271                        rsakey->bytes, 0, 0, &hRsaKey) == 0)
 272         fatalbox("Error importing RSA key!");
 273
 274     /* copy message into buffer */
 275     memcpy(buf, data, length);
 276     dlen = length;
 277
 278     /* using host public key, encrypt the message */
 279     if (CryptEncrypt(hRsaKey, 0, TRUE, 0, buf, &dlen, bufsize) == 0)
 280         fatalbox("Error encrypting using RSA key!");
 281
 282     /*
 283      * For some strange reason, Microsoft CryptEncrypt using public
 284      * key, returns the cyphertext in backwards (little endian)
 285      * order, so reverse it!
 286      */
 287     for (i = 0; i < (int) dlen; i++)
 288         data[i] = buf[dlen - i - 1];   /* make it big endian */
 289
 290     CryptDestroyKey(hRsaKey);
 291     free(buf);
 292     free(pBlob);
 293
 294 }
 295
 296
 297 int rsastr_len(struct RSAKey *key)
 298 {
 299     return 2 * (sizeof(DWORD) + key->bytes) + 10;
 300 }
 301
 302
 303 void rsastr_fmt(char *str, struct RSAKey *key)
 304 {
 305
 306     int len = 0, i;
 307
 308     sprintf(str + len, "%04x", key->exponent);
 309     len += strlen(str + len);
 310
 311     str[len++] = '/';
 312     for (i = 1; i < key->bytes; i++) {
 313         sprintf(str + len, "%02x", key->modulus[i]);
 314         len += strlen(str + len);
 315     }
 316     str[len] = '\0';
 317 }
 318
 319
 320
 321 /* ---------------------------------------------------------*
 322  * DES encryption / decryption functions                    *
 323  * ---------------------------------------------------------*/
 324
 325
 326 void des3_sesskey(unsigned char *key)
 327 {
 328     int i, j;
 329     for (i = 0; i < 2; i++) {
 330         for (j = 0; j < 3; j++) {
 331             hDESKey[i][j] = create_des_key(key + (j * 8));
 332         }
 333     }
 334 }
 335
 336
 337 void des3_encrypt_blk(unsigned char *blk, int len)
 338 {
 339
 340     DWORD dlen;
 341     dlen = len;
 342
 343     if (CryptEncrypt(hDESKey[0][0], 0, FALSE, 0, blk, &dlen, len + 8) == 0)
 344         fatalbox("Error encrypting block!\n");
 345     if (CryptDecrypt(hDESKey[0][1], 0, FALSE, 0, blk, &dlen) == 0)
 346         fatalbox("Error encrypting block!\n");
 347     if (CryptEncrypt(hDESKey[0][2], 0, FALSE, 0, blk, &dlen, len + 8) == 0)
 348         fatalbox("Error encrypting block!\n");
 349 }
 350
 351
 352 void des3_decrypt_blk(unsigned char *blk, int len)
 353 {
 354     DWORD dlen;
 355     dlen = len;
 356
 357     if (CryptDecrypt(hDESKey[1][2], 0, FALSE, 0, blk, &dlen) == 0)
 358         fatalbox("Error decrypting block!\n");
 359     if (CryptEncrypt(hDESKey[1][1], 0, FALSE, 0, blk, &dlen, len + 8) == 0)
 360         fatalbox("Error decrypting block!\n");
 361     if (CryptDecrypt(hDESKey[1][0], 0, FALSE, 0, blk, &dlen) == 0)
 362         fatalbox("Error decrypting block!\n");
 363 }
 364
 365
 366 struct ssh_cipher ssh_3des = {
 367     des3_sesskey,
 368     des3_encrypt_blk,
 369     des3_decrypt_blk
 370 };
 371
 372
 373 void des_sesskey(unsigned char *key)
 374 {
 375     int i;
 376     for (i = 0; i < 2; i++) {
 377         hDESKey[i][0] = create_des_key(key);
 378     }
 379 }
 380
 381
 382 void des_encrypt_blk(unsigned char *blk, int len)
 383 {
 384     DWORD dlen;
 385     dlen = len;
 386     if (CryptEncrypt(hDESKey[0][0], 0, FALSE, 0, blk, &dlen, len + 8) == 0)
 387         fatalbox("Error encrypting block!\n");
 388 }
 389
 390
 391 void des_decrypt_blk(unsigned char *blk, int len)
 392 {
 393     DWORD dlen;
 394     dlen = len;
 395     if (CryptDecrypt(hDESKey[1][0], 0, FALSE, 0, blk, &dlen) == 0)
 396         fatalbox("Error decrypting block!\n");
 397 }
 398
 399 struct ssh_cipher ssh_des = {
 400     des_sesskey,
 401     des_encrypt_blk,
 402     des_decrypt_blk
 403 };
 404
 405
 406 static HCRYPTKEY create_des_key(unsigned char *key)
 407 {
 408
 409     HCRYPTKEY hSessionKey, hPrivateKey;
 410     DWORD dlen = 8;
 411     BLOBHEADER *pbh;
 412     char buf[sizeof(BLOBHEADER) + sizeof(ALG_ID) + 256];
 413
 414     /*
 415      * Need special private key to encrypt session key so we can
 416      * import session key, since only encrypted session keys can be
 417      * imported
 418      */
 419     if (CryptImportKey(hCryptProv, PrivateKeyWithExponentOfOne,
 420                        sizeof(PrivateKeyWithExponentOfOne),
 421                        0, 0, &hPrivateKey) == 0)
 422         return 0;
 423
 424     /* now encrypt session key using special private key */
 425     memcpy(buf + sizeof(BLOBHEADER) + sizeof(ALG_ID), key, 8);
 426     if (CryptEncrypt(hPrivateKey, 0, TRUE, 0,
 427                      buf + sizeof(BLOBHEADER) + sizeof(ALG_ID),
 428                      &dlen, 256) == 0)
 429         return 0;
 430
 431     /* build session key blob */
 432     pbh = (BLOBHEADER *) buf;
 433     pbh->bType = SIMPLEBLOB;
 434     pbh->bVersion = 0x02;
 435     pbh->reserved = 0;
 436     pbh->aiKeyAlg = CALG_DES;
 437     *((ALG_ID *) (buf + sizeof(BLOBHEADER))) = CALG_RSA_KEYX;
 438
 439     /* import session key into key container */
 440     if (CryptImportKey(hCryptProv, buf,
 441                        dlen + sizeof(BLOBHEADER) + sizeof(ALG_ID),
 442                        hPrivateKey, 0, &hSessionKey) == 0)
 443         return 0;
 444
 445     if (hPrivateKey)
 446         CryptDestroyKey(hPrivateKey);
 447
 448     return hSessionKey;
 449
 450 }