crypto/pem/pvkfmt.c

   1 /*
   2  * Copyright 2005-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 /*
  11  * Support for PVK format keys and related structures (such a PUBLICKEYBLOB
  12  * and PRIVATEKEYBLOB).
  13  */
  14
  15 /*
  16  * DSA low level APIs are deprecated for public use, but still ok for
  17  * internal use.
  18  */
  19 #include "internal/deprecated.h"
  20
  21 #include "internal/cryptlib.h"
  22 #include <openssl/pem.h>
  23 #include <openssl/rand.h>
  24 #include <openssl/bn.h>
  25 #if !defined(OPENSSL_NO_RSA) && !defined(OPENSSL_NO_DSA)
  26 # include <openssl/dsa.h>
  27 # include <openssl/rsa.h>
  28
  29 /*
  30  * Utility function: read a DWORD (4 byte unsigned integer) in little endian
  31  * format
  32  */
  33
  34 static unsigned int read_ledword(const unsigned char **in)
  35 {
  36     const unsigned char *p = *in;
  37     unsigned int ret;
  38     ret = *p++;
  39     ret |= (*p++ << 8);
  40     ret |= (*p++ << 16);
  41     ret |= (*p++ << 24);
  42     *in = p;
  43     return ret;
  44 }
  45
  46 /*
  47  * Read a BIGNUM in little endian format. The docs say that this should take
  48  * up bitlen/8 bytes.
  49  */
  50
  51 static int read_lebn(const unsigned char **in, unsigned int nbyte, BIGNUM **r)
  52 {
  53     *r = BN_lebin2bn(*in, nbyte, NULL);
  54     if (*r == NULL)
  55         return 0;
  56     *in += nbyte;
  57     return 1;
  58 }
  59
  60 /* Convert private key blob to EVP_PKEY: RSA and DSA keys supported */
  61
  62 # define MS_PUBLICKEYBLOB        0x6
  63 # define MS_PRIVATEKEYBLOB       0x7
  64 # define MS_RSA1MAGIC            0x31415352L
  65 # define MS_RSA2MAGIC            0x32415352L
  66 # define MS_DSS1MAGIC            0x31535344L
  67 # define MS_DSS2MAGIC            0x32535344L
  68
  69 # define MS_KEYALG_RSA_KEYX      0xa400
  70 # define MS_KEYALG_DSS_SIGN      0x2200
  71
  72 # define MS_KEYTYPE_KEYX         0x1
  73 # define MS_KEYTYPE_SIGN         0x2
  74
  75 /* Maximum length of a blob after header */
  76 # define BLOB_MAX_LENGTH          102400
  77
  78 /* The PVK file magic number: seems to spell out "bobsfile", who is Bob? */
  79 # define MS_PVKMAGIC             0xb0b5f11eL
  80 /* Salt length for PVK files */
  81 # define PVK_SALTLEN             0x10
  82 /* Maximum length in PVK header */
  83 # define PVK_MAX_KEYLEN          102400
  84 /* Maximum salt length */
  85 # define PVK_MAX_SALTLEN         10240
  86
  87 static EVP_PKEY *b2i_rsa(const unsigned char **in,
  88                          unsigned int bitlen, int ispub);
  89 static EVP_PKEY *b2i_dss(const unsigned char **in,
  90                          unsigned int bitlen, int ispub);
  91
  92 static int do_blob_header(const unsigned char **in, unsigned int length,
  93                           unsigned int *pmagic, unsigned int *pbitlen,
  94                           int *pisdss, int *pispub)
  95 {
  96     const unsigned char *p = *in;
  97     if (length < 16)
  98         return 0;
  99     /* bType */
 100     if (*p == MS_PUBLICKEYBLOB) {
 101         if (*pispub == 0) {
 102             PEMerr(PEM_F_DO_BLOB_HEADER, PEM_R_EXPECTING_PRIVATE_KEY_BLOB);
 103             return 0;
 104         }
 105         *pispub = 1;
 106     } else if (*p == MS_PRIVATEKEYBLOB) {
 107         if (*pispub == 1) {
 108             PEMerr(PEM_F_DO_BLOB_HEADER, PEM_R_EXPECTING_PUBLIC_KEY_BLOB);
 109             return 0;
 110         }
 111         *pispub = 0;
 112     } else
 113         return 0;
 114     p++;
 115     /* Version */
 116     if (*p++ != 0x2) {
 117         PEMerr(PEM_F_DO_BLOB_HEADER, PEM_R_BAD_VERSION_NUMBER);
 118         return 0;
 119     }
 120     /* Ignore reserved, aiKeyAlg */
 121     p += 6;
 122     *pmagic = read_ledword(&p);
 123     *pbitlen = read_ledword(&p);
 124     *pisdss = 0;
 125     switch (*pmagic) {
 126
 127     case MS_DSS1MAGIC:
 128         *pisdss = 1;
 129         /* fall thru */
 130     case MS_RSA1MAGIC:
 131         if (*pispub == 0) {
 132             PEMerr(PEM_F_DO_BLOB_HEADER, PEM_R_EXPECTING_PRIVATE_KEY_BLOB);
 133             return 0;
 134         }
 135         break;
 136
 137     case MS_DSS2MAGIC:
 138         *pisdss = 1;
 139         /* fall thru */
 140     case MS_RSA2MAGIC:
 141         if (*pispub == 1) {
 142             PEMerr(PEM_F_DO_BLOB_HEADER, PEM_R_EXPECTING_PUBLIC_KEY_BLOB);
 143             return 0;
 144         }
 145         break;
 146
 147     default:
 148         PEMerr(PEM_F_DO_BLOB_HEADER, PEM_R_BAD_MAGIC_NUMBER);
 149         return -1;
 150     }
 151     *in = p;
 152     return 1;
 153 }
 154
 155 static unsigned int blob_length(unsigned bitlen, int isdss, int ispub)
 156 {
 157     unsigned int nbyte, hnbyte;
 158     nbyte = (bitlen + 7) >> 3;
 159     hnbyte = (bitlen + 15) >> 4;
 160     if (isdss) {
 161
 162         /*
 163          * Expected length: 20 for q + 3 components bitlen each + 24 for seed
 164          * structure.
 165          */
 166         if (ispub)
 167             return 44 + 3 * nbyte;
 168         /*
 169          * Expected length: 20 for q, priv, 2 bitlen components + 24 for seed
 170          * structure.
 171          */
 172         else
 173             return 64 + 2 * nbyte;
 174     } else {
 175         /* Expected length: 4 for 'e' + 'n' */
 176         if (ispub)
 177             return 4 + nbyte;
 178         else
 179             /*
 180              * Expected length: 4 for 'e' and 7 other components. 2
 181              * components are bitlen size, 5 are bitlen/2
 182              */
 183             return 4 + 2 * nbyte + 5 * hnbyte;
 184     }
 185
 186 }
 187
 188 static EVP_PKEY *do_b2i(const unsigned char **in, unsigned int length,
 189                         int ispub)
 190 {
 191     const unsigned char *p = *in;
 192     unsigned int bitlen, magic;
 193     int isdss;
 194     if (do_blob_header(&p, length, &magic, &bitlen, &isdss, &ispub) <= 0) {
 195         PEMerr(PEM_F_DO_B2I, PEM_R_KEYBLOB_HEADER_PARSE_ERROR);
 196         return NULL;
 197     }
 198     length -= 16;
 199     if (length < blob_length(bitlen, isdss, ispub)) {
 200         PEMerr(PEM_F_DO_B2I, PEM_R_KEYBLOB_TOO_SHORT);
 201         return NULL;
 202     }
 203     if (isdss)
 204         return b2i_dss(&p, bitlen, ispub);
 205     else
 206         return b2i_rsa(&p, bitlen, ispub);
 207 }
 208
 209 static EVP_PKEY *do_b2i_bio(BIO *in, int ispub)
 210 {
 211     const unsigned char *p;
 212     unsigned char hdr_buf[16], *buf = NULL;
 213     unsigned int bitlen, magic, length;
 214     int isdss;
 215     EVP_PKEY *ret = NULL;
 216     if (BIO_read(in, hdr_buf, 16) != 16) {
 217         PEMerr(PEM_F_DO_B2I_BIO, PEM_R_KEYBLOB_TOO_SHORT);
 218         return NULL;
 219     }
 220     p = hdr_buf;
 221     if (do_blob_header(&p, 16, &magic, &bitlen, &isdss, &ispub) <= 0)
 222         return NULL;
 223
 224     length = blob_length(bitlen, isdss, ispub);
 225     if (length > BLOB_MAX_LENGTH) {
 226         PEMerr(PEM_F_DO_B2I_BIO, PEM_R_HEADER_TOO_LONG);
 227         return NULL;
 228     }
 229     buf = OPENSSL_malloc(length);
 230     if (buf == NULL) {
 231         PEMerr(PEM_F_DO_B2I_BIO, ERR_R_MALLOC_FAILURE);
 232         goto err;
 233     }
 234     p = buf;
 235     if (BIO_read(in, buf, length) != (int)length) {
 236         PEMerr(PEM_F_DO_B2I_BIO, PEM_R_KEYBLOB_TOO_SHORT);
 237         goto err;
 238     }
 239
 240     if (isdss)
 241         ret = b2i_dss(&p, bitlen, ispub);
 242     else
 243         ret = b2i_rsa(&p, bitlen, ispub);
 244
 245  err:
 246     OPENSSL_free(buf);
 247     return ret;
 248 }
 249
 250 static EVP_PKEY *b2i_dss(const unsigned char **in,
 251                          unsigned int bitlen, int ispub)
 252 {
 253     const unsigned char *p = *in;
 254     EVP_PKEY *ret = NULL;
 255     DSA *dsa = NULL;
 256     BN_CTX *ctx = NULL;
 257     unsigned int nbyte;
 258     BIGNUM *pbn = NULL, *qbn = NULL, *gbn = NULL, *priv_key = NULL;
 259     BIGNUM *pub_key = NULL;
 260
 261     nbyte = (bitlen + 7) >> 3;
 262
 263     dsa = DSA_new();
 264     ret = EVP_PKEY_new();
 265     if (dsa == NULL || ret == NULL)
 266         goto memerr;
 267     if (!read_lebn(&p, nbyte, &pbn))
 268         goto memerr;
 269
 270     if (!read_lebn(&p, 20, &qbn))
 271         goto memerr;
 272
 273     if (!read_lebn(&p, nbyte, &gbn))
 274         goto memerr;
 275
 276     if (ispub) {
 277         if (!read_lebn(&p, nbyte, &pub_key))
 278             goto memerr;
 279     } else {
 280         if (!read_lebn(&p, 20, &priv_key))
 281             goto memerr;
 282
 283         /* Set constant time flag before public key calculation */
 284         BN_set_flags(priv_key, BN_FLG_CONSTTIME);
 285
 286         /* Calculate public key */
 287         pub_key = BN_new();
 288         if (pub_key == NULL)
 289             goto memerr;
 290         if ((ctx = BN_CTX_new()) == NULL)
 291             goto memerr;
 292
 293         if (!BN_mod_exp(pub_key, gbn, priv_key, pbn, ctx))
 294             goto memerr;
 295
 296         BN_CTX_free(ctx);
 297         ctx = NULL;
 298     }
 299     if (!DSA_set0_pqg(dsa, pbn, qbn, gbn))
 300         goto memerr;
 301     pbn = qbn = gbn = NULL;
 302     if (!DSA_set0_key(dsa, pub_key, priv_key))
 303         goto memerr;
 304     pub_key = priv_key = NULL;
 305
 306     if (!EVP_PKEY_set1_DSA(ret, dsa))
 307         goto memerr;
 308     DSA_free(dsa);
 309     *in = p;
 310     return ret;
 311
 312  memerr:
 313     PEMerr(PEM_F_B2I_DSS, ERR_R_MALLOC_FAILURE);
 314     DSA_free(dsa);
 315     BN_free(pbn);
 316     BN_free(qbn);
 317     BN_free(gbn);
 318     BN_free(pub_key);
 319     BN_free(priv_key);
 320     EVP_PKEY_free(ret);
 321     BN_CTX_free(ctx);
 322     return NULL;
 323 }
 324
 325 static EVP_PKEY *b2i_rsa(const unsigned char **in,
 326                          unsigned int bitlen, int ispub)
 327 {
 328     const unsigned char *pin = *in;
 329     EVP_PKEY *ret = NULL;
 330     BIGNUM *e = NULL, *n = NULL, *d = NULL;
 331     BIGNUM *p = NULL, *q = NULL, *dmp1 = NULL, *dmq1 = NULL, *iqmp = NULL;
 332     RSA *rsa = NULL;
 333     unsigned int nbyte, hnbyte;
 334     nbyte = (bitlen + 7) >> 3;
 335     hnbyte = (bitlen + 15) >> 4;
 336     rsa = RSA_new();
 337     ret = EVP_PKEY_new();
 338     if (rsa == NULL || ret == NULL)
 339         goto memerr;
 340     e = BN_new();
 341     if (e == NULL)
 342         goto memerr;
 343     if (!BN_set_word(e, read_ledword(&pin)))
 344         goto memerr;
 345     if (!read_lebn(&pin, nbyte, &n))
 346         goto memerr;
 347     if (!ispub) {
 348         if (!read_lebn(&pin, hnbyte, &p))
 349             goto memerr;
 350         if (!read_lebn(&pin, hnbyte, &q))
 351             goto memerr;
 352         if (!read_lebn(&pin, hnbyte, &dmp1))
 353             goto memerr;
 354         if (!read_lebn(&pin, hnbyte, &dmq1))
 355             goto memerr;
 356         if (!read_lebn(&pin, hnbyte, &iqmp))
 357             goto memerr;
 358         if (!read_lebn(&pin, nbyte, &d))
 359             goto memerr;
 360         if (!RSA_set0_factors(rsa, p, q))
 361             goto memerr;
 362         p = q = NULL;
 363         if (!RSA_set0_crt_params(rsa, dmp1, dmq1, iqmp))
 364             goto memerr;
 365         dmp1 = dmq1 = iqmp = NULL;
 366     }
 367     if (!RSA_set0_key(rsa, n, e, d))
 368         goto memerr;
 369     n = e = d = NULL;
 370
 371     if (!EVP_PKEY_set1_RSA(ret, rsa))
 372         goto memerr;
 373     RSA_free(rsa);
 374     *in = pin;
 375     return ret;
 376  memerr:
 377     PEMerr(PEM_F_B2I_RSA, ERR_R_MALLOC_FAILURE);
 378     BN_free(e);
 379     BN_free(n);
 380     BN_free(p);
 381     BN_free(q);
 382     BN_free(dmp1);
 383     BN_free(dmq1);
 384     BN_free(iqmp);
 385     BN_free(d);
 386     RSA_free(rsa);
 387     EVP_PKEY_free(ret);
 388     return NULL;
 389 }
 390
 391 EVP_PKEY *b2i_PrivateKey(const unsigned char **in, long length)
 392 {
 393     return do_b2i(in, length, 0);
 394 }
 395
 396 EVP_PKEY *b2i_PublicKey(const unsigned char **in, long length)
 397 {
 398     return do_b2i(in, length, 1);
 399 }
 400
 401 EVP_PKEY *b2i_PrivateKey_bio(BIO *in)
 402 {
 403     return do_b2i_bio(in, 0);
 404 }
 405
 406 EVP_PKEY *b2i_PublicKey_bio(BIO *in)
 407 {
 408     return do_b2i_bio(in, 1);
 409 }
 410
 411 static void write_ledword(unsigned char **out, unsigned int dw)
 412 {
 413     unsigned char *p = *out;
 414     *p++ = dw & 0xff;
 415     *p++ = (dw >> 8) & 0xff;
 416     *p++ = (dw >> 16) & 0xff;
 417     *p++ = (dw >> 24) & 0xff;
 418     *out = p;
 419 }
 420
 421 static void write_lebn(unsigned char **out, const BIGNUM *bn, int len)
 422 {
 423     BN_bn2lebinpad(bn, *out, len);
 424     *out += len;
 425 }
 426
 427 static int check_bitlen_rsa(RSA *rsa, int ispub, unsigned int *magic);
 428 static int check_bitlen_dsa(DSA *dsa, int ispub, unsigned int *magic);
 429
 430 static void write_rsa(unsigned char **out, RSA *rsa, int ispub);
 431 static void write_dsa(unsigned char **out, DSA *dsa, int ispub);
 432
 433 static int do_i2b(unsigned char **out, const EVP_PKEY *pk, int ispub)
 434 {
 435     unsigned char *p;
 436     unsigned int bitlen, magic = 0, keyalg;
 437     int outlen, noinc = 0;
 438     int pktype = EVP_PKEY_id(pk);
 439     if (pktype == EVP_PKEY_DSA) {
 440         bitlen = check_bitlen_dsa(EVP_PKEY_get0_DSA(pk), ispub, &magic);
 441         keyalg = MS_KEYALG_DSS_SIGN;
 442     } else if (pktype == EVP_PKEY_RSA) {
 443         bitlen = check_bitlen_rsa(EVP_PKEY_get0_RSA(pk), ispub, &magic);
 444         keyalg = MS_KEYALG_RSA_KEYX;
 445     } else
 446         return -1;
 447     if (bitlen == 0)
 448         return -1;
 449     outlen = 16 + blob_length(bitlen,
 450                               keyalg == MS_KEYALG_DSS_SIGN ? 1 : 0, ispub);
 451     if (out == NULL)
 452         return outlen;
 453     if (*out)
 454         p = *out;
 455     else {
 456         if ((p = OPENSSL_malloc(outlen)) == NULL) {
 457             PEMerr(PEM_F_DO_I2B, ERR_R_MALLOC_FAILURE);
 458             return -1;
 459         }
 460         *out = p;
 461         noinc = 1;
 462     }
 463     if (ispub)
 464         *p++ = MS_PUBLICKEYBLOB;
 465     else
 466         *p++ = MS_PRIVATEKEYBLOB;
 467     *p++ = 0x2;
 468     *p++ = 0;
 469     *p++ = 0;
 470     write_ledword(&p, keyalg);
 471     write_ledword(&p, magic);
 472     write_ledword(&p, bitlen);
 473     if (keyalg == MS_KEYALG_DSS_SIGN)
 474         write_dsa(&p, EVP_PKEY_get0_DSA(pk), ispub);
 475     else
 476         write_rsa(&p, EVP_PKEY_get0_RSA(pk), ispub);
 477     if (!noinc)
 478         *out += outlen;
 479     return outlen;
 480 }
 481
 482 static int do_i2b_bio(BIO *out, const EVP_PKEY *pk, int ispub)
 483 {
 484     unsigned char *tmp = NULL;
 485     int outlen, wrlen;
 486     outlen = do_i2b(&tmp, pk, ispub);
 487     if (outlen < 0)
 488         return -1;
 489     wrlen = BIO_write(out, tmp, outlen);
 490     OPENSSL_free(tmp);
 491     if (wrlen == outlen)
 492         return outlen;
 493     return -1;
 494 }
 495
 496 static int check_bitlen_dsa(DSA *dsa, int ispub, unsigned int *pmagic)
 497 {
 498     int bitlen;
 499     const BIGNUM *p = NULL, *q = NULL, *g = NULL;
 500     const BIGNUM *pub_key = NULL, *priv_key = NULL;
 501
 502     DSA_get0_pqg(dsa, &p, &q, &g);
 503     DSA_get0_key(dsa, &pub_key, &priv_key);
 504     bitlen = BN_num_bits(p);
 505     if ((bitlen & 7) || (BN_num_bits(q) != 160)
 506         || (BN_num_bits(g) > bitlen))
 507         goto badkey;
 508     if (ispub) {
 509         if (BN_num_bits(pub_key) > bitlen)
 510             goto badkey;
 511         *pmagic = MS_DSS1MAGIC;
 512     } else {
 513         if (BN_num_bits(priv_key) > 160)
 514             goto badkey;
 515         *pmagic = MS_DSS2MAGIC;
 516     }
 517
 518     return bitlen;
 519  badkey:
 520     PEMerr(PEM_F_CHECK_BITLEN_DSA, PEM_R_UNSUPPORTED_KEY_COMPONENTS);
 521     return 0;
 522 }
 523
 524 static int check_bitlen_rsa(RSA *rsa, int ispub, unsigned int *pmagic)
 525 {
 526     int nbyte, hnbyte, bitlen;
 527     const BIGNUM *e;
 528
 529     RSA_get0_key(rsa, NULL, &e, NULL);
 530     if (BN_num_bits(e) > 32)
 531         goto badkey;
 532     bitlen = RSA_bits(rsa);
 533     nbyte = RSA_size(rsa);
 534     hnbyte = (bitlen + 15) >> 4;
 535     if (ispub) {
 536         *pmagic = MS_RSA1MAGIC;
 537         return bitlen;
 538     } else {
 539         const BIGNUM *d, *p, *q, *iqmp, *dmp1, *dmq1;
 540
 541         *pmagic = MS_RSA2MAGIC;
 542
 543         /*
 544          * For private key each component must fit within nbyte or hnbyte.
 545          */
 546         RSA_get0_key(rsa, NULL, NULL, &d);
 547         if (BN_num_bytes(d) > nbyte)
 548             goto badkey;
 549         RSA_get0_factors(rsa, &p, &q);
 550         RSA_get0_crt_params(rsa, &dmp1, &dmq1, &iqmp);
 551         if ((BN_num_bytes(iqmp) > hnbyte)
 552             || (BN_num_bytes(p) > hnbyte)
 553             || (BN_num_bytes(q) > hnbyte)
 554             || (BN_num_bytes(dmp1) > hnbyte)
 555             || (BN_num_bytes(dmq1) > hnbyte))
 556             goto badkey;
 557     }
 558     return bitlen;
 559  badkey:
 560     PEMerr(PEM_F_CHECK_BITLEN_RSA, PEM_R_UNSUPPORTED_KEY_COMPONENTS);
 561     return 0;
 562 }
 563
 564 static void write_rsa(unsigned char **out, RSA *rsa, int ispub)
 565 {
 566     int nbyte, hnbyte;
 567     const BIGNUM *n, *d, *e, *p, *q, *iqmp, *dmp1, *dmq1;
 568
 569     nbyte = RSA_size(rsa);
 570     hnbyte = (RSA_bits(rsa) + 15) >> 4;
 571     RSA_get0_key(rsa, &n, &e, &d);
 572     write_lebn(out, e, 4);
 573     write_lebn(out, n, nbyte);
 574     if (ispub)
 575         return;
 576     RSA_get0_factors(rsa, &p, &q);
 577     RSA_get0_crt_params(rsa, &dmp1, &dmq1, &iqmp);
 578     write_lebn(out, p, hnbyte);
 579     write_lebn(out, q, hnbyte);
 580     write_lebn(out, dmp1, hnbyte);
 581     write_lebn(out, dmq1, hnbyte);
 582     write_lebn(out, iqmp, hnbyte);
 583     write_lebn(out, d, nbyte);
 584 }
 585
 586 static void write_dsa(unsigned char **out, DSA *dsa, int ispub)
 587 {
 588     int nbyte;
 589     const BIGNUM *p = NULL, *q = NULL, *g = NULL;
 590     const BIGNUM *pub_key = NULL, *priv_key = NULL;
 591
 592     DSA_get0_pqg(dsa, &p, &q, &g);
 593     DSA_get0_key(dsa, &pub_key, &priv_key);
 594     nbyte = BN_num_bytes(p);
 595     write_lebn(out, p, nbyte);
 596     write_lebn(out, q, 20);
 597     write_lebn(out, g, nbyte);
 598     if (ispub)
 599         write_lebn(out, pub_key, nbyte);
 600     else
 601         write_lebn(out, priv_key, 20);
 602     /* Set "invalid" for seed structure values */
 603     memset(*out, 0xff, 24);
 604     *out += 24;
 605     return;
 606 }
 607
 608 int i2b_PrivateKey_bio(BIO *out, const EVP_PKEY *pk)
 609 {
 610     return do_i2b_bio(out, pk, 0);
 611 }
 612
 613 int i2b_PublicKey_bio(BIO *out, const EVP_PKEY *pk)
 614 {
 615     return do_i2b_bio(out, pk, 1);
 616 }
 617
 618 # ifndef OPENSSL_NO_RC4
 619
 620 static int do_PVK_header(const unsigned char **in, unsigned int length,
 621                          int skip_magic,
 622                          unsigned int *psaltlen, unsigned int *pkeylen)
 623 {
 624     const unsigned char *p = *in;
 625     unsigned int pvk_magic, is_encrypted;
 626
 627     if (skip_magic) {
 628         if (length < 20) {
 629             PEMerr(PEM_F_DO_PVK_HEADER, PEM_R_PVK_TOO_SHORT);
 630             return 0;
 631         }
 632     } else {
 633         if (length < 24) {
 634             PEMerr(PEM_F_DO_PVK_HEADER, PEM_R_PVK_TOO_SHORT);
 635             return 0;
 636         }
 637         pvk_magic = read_ledword(&p);
 638         if (pvk_magic != MS_PVKMAGIC) {
 639             PEMerr(PEM_F_DO_PVK_HEADER, PEM_R_BAD_MAGIC_NUMBER);
 640             return 0;
 641         }
 642     }
 643     /* Skip reserved */
 644     p += 4;
 645     /*
 646      * keytype =
 647      */ read_ledword(&p);
 648     is_encrypted = read_ledword(&p);
 649     *psaltlen = read_ledword(&p);
 650     *pkeylen = read_ledword(&p);
 651
 652     if (*pkeylen > PVK_MAX_KEYLEN || *psaltlen > PVK_MAX_SALTLEN)
 653         return 0;
 654
 655     if (is_encrypted && *psaltlen == 0) {
 656         PEMerr(PEM_F_DO_PVK_HEADER, PEM_R_INCONSISTENT_HEADER);
 657         return 0;
 658     }
 659
 660     *in = p;
 661     return 1;
 662 }
 663
 664 static int derive_pvk_key(unsigned char *key,
 665                           const unsigned char *salt, unsigned int saltlen,
 666                           const unsigned char *pass, int passlen)
 667 {
 668     EVP_MD_CTX *mctx = EVP_MD_CTX_new();
 669     int rv = 1;
 670     if (mctx == NULL
 671         || !EVP_DigestInit_ex(mctx, EVP_sha1(), NULL)
 672         || !EVP_DigestUpdate(mctx, salt, saltlen)
 673         || !EVP_DigestUpdate(mctx, pass, passlen)
 674         || !EVP_DigestFinal_ex(mctx, key, NULL))
 675         rv = 0;
 676
 677     EVP_MD_CTX_free(mctx);
 678     return rv;
 679 }
 680
 681 static EVP_PKEY *do_PVK_body(const unsigned char **in,
 682                              unsigned int saltlen, unsigned int keylen,
 683                              pem_password_cb *cb, void *u)
 684 {
 685     EVP_PKEY *ret = NULL;
 686     const unsigned char *p = *in;
 687     unsigned int magic;
 688     unsigned char *enctmp = NULL, *q;
 689     unsigned char keybuf[20];
 690
 691     EVP_CIPHER_CTX *cctx = EVP_CIPHER_CTX_new();
 692     if (saltlen) {
 693         char psbuf[PEM_BUFSIZE];
 694         int enctmplen, inlen;
 695         if (cb)
 696             inlen = cb(psbuf, PEM_BUFSIZE, 0, u);
 697         else
 698             inlen = PEM_def_callback(psbuf, PEM_BUFSIZE, 0, u);
 699         if (inlen < 0) {
 700             PEMerr(PEM_F_DO_PVK_BODY, PEM_R_BAD_PASSWORD_READ);
 701             goto err;
 702         }
 703         enctmp = OPENSSL_malloc(keylen + 8);
 704         if (enctmp == NULL) {
 705             PEMerr(PEM_F_DO_PVK_BODY, ERR_R_MALLOC_FAILURE);
 706             goto err;
 707         }
 708         if (!derive_pvk_key(keybuf, p, saltlen,
 709                             (unsigned char *)psbuf, inlen))
 710             goto err;
 711         p += saltlen;
 712         /* Copy BLOBHEADER across, decrypt rest */
 713         memcpy(enctmp, p, 8);
 714         p += 8;
 715         if (keylen < 8) {
 716             PEMerr(PEM_F_DO_PVK_BODY, PEM_R_PVK_TOO_SHORT);
 717             goto err;
 718         }
 719         inlen = keylen - 8;
 720         q = enctmp + 8;
 721         if (!EVP_DecryptInit_ex(cctx, EVP_rc4(), NULL, keybuf, NULL))
 722             goto err;
 723         if (!EVP_DecryptUpdate(cctx, q, &enctmplen, p, inlen))
 724             goto err;
 725         if (!EVP_DecryptFinal_ex(cctx, q + enctmplen, &enctmplen))
 726             goto err;
 727         magic = read_ledword((const unsigned char **)&q);
 728         if (magic != MS_RSA2MAGIC && magic != MS_DSS2MAGIC) {
 729             q = enctmp + 8;
 730             memset(keybuf + 5, 0, 11);
 731             if (!EVP_DecryptInit_ex(cctx, EVP_rc4(), NULL, keybuf, NULL))
 732                 goto err;
 733             if (!EVP_DecryptUpdate(cctx, q, &enctmplen, p, inlen))
 734                 goto err;
 735             if (!EVP_DecryptFinal_ex(cctx, q + enctmplen, &enctmplen))
 736                 goto err;
 737             magic = read_ledword((const unsigned char **)&q);
 738             if (magic != MS_RSA2MAGIC && magic != MS_DSS2MAGIC) {
 739                 PEMerr(PEM_F_DO_PVK_BODY, PEM_R_BAD_DECRYPT);
 740                 goto err;
 741             }
 742         }
 743         p = enctmp;
 744     }
 745
 746     ret = b2i_PrivateKey(&p, keylen);
 747  err:
 748     EVP_CIPHER_CTX_free(cctx);
 749     if (enctmp != NULL) {
 750         OPENSSL_cleanse(keybuf, sizeof(keybuf));
 751         OPENSSL_free(enctmp);
 752     }
 753     return ret;
 754 }
 755
 756 EVP_PKEY *b2i_PVK_bio(BIO *in, pem_password_cb *cb, void *u)
 757 {
 758     unsigned char pvk_hdr[24], *buf = NULL;
 759     const unsigned char *p;
 760     int buflen;
 761     EVP_PKEY *ret = NULL;
 762     unsigned int saltlen, keylen;
 763     if (BIO_read(in, pvk_hdr, 24) != 24) {
 764         PEMerr(PEM_F_B2I_PVK_BIO, PEM_R_PVK_DATA_TOO_SHORT);
 765         return NULL;
 766     }
 767     p = pvk_hdr;
 768
 769     if (!do_PVK_header(&p, 24, 0, &saltlen, &keylen))
 770         return 0;
 771     buflen = (int)keylen + saltlen;
 772     buf = OPENSSL_malloc(buflen);
 773     if (buf == NULL) {
 774         PEMerr(PEM_F_B2I_PVK_BIO, ERR_R_MALLOC_FAILURE);
 775         return 0;
 776     }
 777     p = buf;
 778     if (BIO_read(in, buf, buflen) != buflen) {
 779         PEMerr(PEM_F_B2I_PVK_BIO, PEM_R_PVK_DATA_TOO_SHORT);
 780         goto err;
 781     }
 782     ret = do_PVK_body(&p, saltlen, keylen, cb, u);
 783
 784  err:
 785     OPENSSL_clear_free(buf, buflen);
 786     return ret;
 787 }
 788
 789 static int i2b_PVK(unsigned char **out, const EVP_PKEY *pk, int enclevel,
 790                    pem_password_cb *cb, void *u)
 791 {
 792     int outlen = 24, pklen;
 793     unsigned char *p = NULL, *start = NULL, *salt = NULL;
 794     EVP_CIPHER_CTX *cctx = NULL;
 795     if (enclevel)
 796         outlen += PVK_SALTLEN;
 797     pklen = do_i2b(NULL, pk, 0);
 798     if (pklen < 0)
 799         return -1;
 800     outlen += pklen;
 801     if (out == NULL)
 802         return outlen;
 803     if (*out != NULL) {
 804         p = *out;
 805     } else {
 806         start = p = OPENSSL_malloc(outlen);
 807         if (p == NULL) {
 808             PEMerr(PEM_F_I2B_PVK, ERR_R_MALLOC_FAILURE);
 809             return -1;
 810         }
 811     }
 812
 813     cctx = EVP_CIPHER_CTX_new();
 814     if (cctx == NULL)
 815         goto error;
 816
 817     write_ledword(&p, MS_PVKMAGIC);
 818     write_ledword(&p, 0);
 819     if (EVP_PKEY_id(pk) == EVP_PKEY_DSA)
 820         write_ledword(&p, MS_KEYTYPE_SIGN);
 821     else
 822         write_ledword(&p, MS_KEYTYPE_KEYX);
 823     write_ledword(&p, enclevel ? 1 : 0);
 824     write_ledword(&p, enclevel ? PVK_SALTLEN : 0);
 825     write_ledword(&p, pklen);
 826     if (enclevel) {
 827         if (RAND_bytes(p, PVK_SALTLEN) <= 0)
 828             goto error;
 829         salt = p;
 830         p += PVK_SALTLEN;
 831     }
 832     do_i2b(&p, pk, 0);
 833     if (enclevel != 0) {
 834         char psbuf[PEM_BUFSIZE];
 835         unsigned char keybuf[20];
 836         int enctmplen, inlen;
 837         if (cb)
 838             inlen = cb(psbuf, PEM_BUFSIZE, 1, u);
 839         else
 840             inlen = PEM_def_callback(psbuf, PEM_BUFSIZE, 1, u);
 841         if (inlen <= 0) {
 842             PEMerr(PEM_F_I2B_PVK, PEM_R_BAD_PASSWORD_READ);
 843             goto error;
 844         }
 845         if (!derive_pvk_key(keybuf, salt, PVK_SALTLEN,
 846                             (unsigned char *)psbuf, inlen))
 847             goto error;
 848         if (enclevel == 1)
 849             memset(keybuf + 5, 0, 11);
 850         p = salt + PVK_SALTLEN + 8;
 851         if (!EVP_EncryptInit_ex(cctx, EVP_rc4(), NULL, keybuf, NULL))
 852             goto error;
 853         OPENSSL_cleanse(keybuf, 20);
 854         if (!EVP_DecryptUpdate(cctx, p, &enctmplen, p, pklen - 8))
 855             goto error;
 856         if (!EVP_DecryptFinal_ex(cctx, p + enctmplen, &enctmplen))
 857             goto error;
 858     }
 859
 860     EVP_CIPHER_CTX_free(cctx);
 861
 862     if (*out == NULL)
 863         *out = start;
 864
 865     return outlen;
 866
 867  error:
 868     EVP_CIPHER_CTX_free(cctx);
 869     if (*out == NULL)
 870         OPENSSL_free(start);
 871     return -1;
 872 }
 873
 874 int i2b_PVK_bio(BIO *out, const EVP_PKEY *pk, int enclevel,
 875                 pem_password_cb *cb, void *u)
 876 {
 877     unsigned char *tmp = NULL;
 878     int outlen, wrlen;
 879     outlen = i2b_PVK(&tmp, pk, enclevel, cb, u);
 880     if (outlen < 0)
 881         return -1;
 882     wrlen = BIO_write(out, tmp, outlen);
 883     OPENSSL_free(tmp);
 884     if (wrlen == outlen) {
 885         PEMerr(PEM_F_I2B_PVK_BIO, PEM_R_BIO_WRITE_FAILURE);
 886         return outlen;
 887     }
 888     return -1;
 889 }
 890
 891 # endif
 892
 893 #endif