crypto/pem/pvkfmt.c

   1 /*
   2  * Copyright 2005-2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (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 #include "internal/cryptlib.h"
  16 #include <openssl/pem.h>
  17 #include <openssl/rand.h>
  18 #include <openssl/bn.h>
  19 #if !defined(OPENSSL_NO_RSA) && !defined(OPENSSL_NO_DSA)
  20 # include <openssl/dsa.h>
  21 # include <openssl/rsa.h>
  22
  23 /*
  24  * Utility function: read a DWORD (4 byte unsigned integer) in little endian
  25  * format
  26  */
  27
  28 static unsigned int read_ledword(const unsigned char **in)
  29 {
  30     const unsigned char *p = *in;
  31     unsigned int ret;
  32     ret = *p++;
  33     ret |= (*p++ << 8);
  34     ret |= (*p++ << 16);
  35     ret |= (*p++ << 24);
  36     *in = p;
  37     return ret;
  38 }
  39
  40 /*
  41  * Read a BIGNUM in little endian format. The docs say that this should take
  42  * up bitlen/8 bytes.
  43  */
  44
  45 static int read_lebn(const unsigned char **in, unsigned int nbyte, BIGNUM **r)
  46 {
  47     *r = BN_lebin2bn(*in, nbyte, NULL);
  48     if (*r == NULL)
  49         return 0;
  50     *in += nbyte;
  51     return 1;
  52 }
  53
  54 /* Convert private key blob to EVP_PKEY: RSA and DSA keys supported */
  55
  56 # define MS_PUBLICKEYBLOB        0x6
  57 # define MS_PRIVATEKEYBLOB       0x7
  58 # define MS_RSA1MAGIC            0x31415352L
  59 # define MS_RSA2MAGIC            0x32415352L
  60 # define MS_DSS1MAGIC            0x31535344L
  61 # define MS_DSS2MAGIC            0x32535344L
  62
  63 # define MS_KEYALG_RSA_KEYX      0xa400
  64 # define MS_KEYALG_DSS_SIGN      0x2200
  65
  66 # define MS_KEYTYPE_KEYX         0x1
  67 # define MS_KEYTYPE_SIGN         0x2
  68
  69 /* Maximum length of a blob after header */
  70 # define BLOB_MAX_LENGTH          102400
  71
  72 /* The PVK file magic number: seems to spell out "bobsfile", who is Bob? */
  73 # define MS_PVKMAGIC             0xb0b5f11eL
  74 /* Salt length for PVK files */
  75 # define PVK_SALTLEN             0x10
  76 /* Maximum length in PVK header */
  77 # define PVK_MAX_KEYLEN          102400
  78 /* Maximum salt length */
  79 # define PVK_MAX_SALTLEN         10240
  80
  81 static EVP_PKEY *b2i_rsa(const unsigned char **in,
  82                          unsigned int bitlen, int ispub);
  83 static EVP_PKEY *b2i_dss(const unsigned char **in,
  84                          unsigned int bitlen, int ispub);
  85
  86 static int do_blob_header(const unsigned char **in, unsigned int length,
  87                           unsigned int *pmagic, unsigned int *pbitlen,
  88                           int *pisdss, int *pispub)
  89 {
  90     const unsigned char *p = *in;
  91     if (length < 16)
  92         return 0;
  93     /* bType */
  94     if (*p == MS_PUBLICKEYBLOB) {
  95         if (*pispub == 0) {
  96             PEMerr(PEM_F_DO_BLOB_HEADER, PEM_R_EXPECTING_PRIVATE_KEY_BLOB);
  97             return 0;
  98         }
  99         *pispub = 1;
 100     } else if (*p == MS_PRIVATEKEYBLOB) {
 101         if (*pispub == 1) {
 102             PEMerr(PEM_F_DO_BLOB_HEADER, PEM_R_EXPECTING_PUBLIC_KEY_BLOB);
 103             return 0;
 104         }
 105         *pispub = 0;
 106     } else
 107         return 0;
 108     p++;
 109     /* Version */
 110     if (*p++ != 0x2) {
 111         PEMerr(PEM_F_DO_BLOB_HEADER, PEM_R_BAD_VERSION_NUMBER);
 112         return 0;
 113     }
 114     /* Ignore reserved, aiKeyAlg */
 115     p += 6;
 116     *pmagic = read_ledword(&p);
 117     *pbitlen = read_ledword(&p);
 118     *pisdss = 0;
 119     switch (*pmagic) {
 120
 121     case MS_DSS1MAGIC:
 122         *pisdss = 1;
 123         /* fall thru */
 124     case MS_RSA1MAGIC:
 125         if (*pispub == 0) {
 126             PEMerr(PEM_F_DO_BLOB_HEADER, PEM_R_EXPECTING_PRIVATE_KEY_BLOB);
 127             return 0;
 128         }
 129         break;
 130
 131     case MS_DSS2MAGIC:
 132         *pisdss = 1;
 133         /* fall thru */
 134     case MS_RSA2MAGIC:
 135         if (*pispub == 1) {
 136             PEMerr(PEM_F_DO_BLOB_HEADER, PEM_R_EXPECTING_PUBLIC_KEY_BLOB);
 137             return 0;
 138         }
 139         break;
 140
 141     default:
 142         PEMerr(PEM_F_DO_BLOB_HEADER, PEM_R_BAD_MAGIC_NUMBER);
 143         return -1;
 144     }
 145     *in = p;
 146     return 1;
 147 }
 148
 149 static unsigned int blob_length(unsigned bitlen, int isdss, int ispub)
 150 {
 151     unsigned int nbyte, hnbyte;
 152     nbyte = (bitlen + 7) >> 3;
 153     hnbyte = (bitlen + 15) >> 4;
 154     if (isdss) {
 155
 156         /*
 157          * Expected length: 20 for q + 3 components bitlen each + 24 for seed
 158          * structure.
 159          */
 160         if (ispub)
 161             return 44 + 3 * nbyte;
 162         /*
 163          * Expected length: 20 for q, priv, 2 bitlen components + 24 for seed
 164          * structure.
 165          */
 166         else
 167             return 64 + 2 * nbyte;
 168     } else {
 169         /* Expected length: 4 for 'e' + 'n' */
 170         if (ispub)
 171             return 4 + nbyte;
 172         else
 173             /*
 174              * Expected length: 4 for 'e' and 7 other components. 2
 175              * components are bitlen size, 5 are bitlen/2
 176              */
 177             return 4 + 2 * nbyte + 5 * hnbyte;
 178     }
 179
 180 }
 181
 182 static EVP_PKEY *do_b2i(const unsigned char **in, unsigned int length,
 183                         int ispub)
 184 {
 185     const unsigned char *p = *in;
 186     unsigned int bitlen, magic;
 187     int isdss;
 188     if (do_blob_header(&p, length, &magic, &bitlen, &isdss, &ispub) <= 0) {
 189         PEMerr(PEM_F_DO_B2I, PEM_R_KEYBLOB_HEADER_PARSE_ERROR);
 190         return NULL;
 191     }
 192     length -= 16;
 193     if (length < blob_length(bitlen, isdss, ispub)) {
 194         PEMerr(PEM_F_DO_B2I, PEM_R_KEYBLOB_TOO_SHORT);
 195         return NULL;
 196     }
 197     if (isdss)
 198         return b2i_dss(&p, bitlen, ispub);
 199     else
 200         return b2i_rsa(&p, bitlen, ispub);
 201 }
 202
 203 static EVP_PKEY *do_b2i_bio(BIO *in, int ispub)
 204 {
 205     const unsigned char *p;
 206     unsigned char hdr_buf[16], *buf = NULL;
 207     unsigned int bitlen, magic, length;
 208     int isdss;
 209     EVP_PKEY *ret = NULL;
 210     if (BIO_read(in, hdr_buf, 16) != 16) {
 211         PEMerr(PEM_F_DO_B2I_BIO, PEM_R_KEYBLOB_TOO_SHORT);
 212         return NULL;
 213     }
 214     p = hdr_buf;
 215     if (do_blob_header(&p, 16, &magic, &bitlen, &isdss, &ispub) <= 0)
 216         return NULL;
 217
 218     length = blob_length(bitlen, isdss, ispub);
 219     if (length > BLOB_MAX_LENGTH) {
 220         PEMerr(PEM_F_DO_B2I_BIO, PEM_R_HEADER_TOO_LONG);
 221         return NULL;
 222     }
 223     buf = OPENSSL_malloc(length);
 224     if (buf == NULL) {
 225         PEMerr(PEM_F_DO_B2I_BIO, ERR_R_MALLOC_FAILURE);
 226         goto err;
 227     }
 228     p = buf;
 229     if (BIO_read(in, buf, length) != (int)length) {
 230         PEMerr(PEM_F_DO_B2I_BIO, PEM_R_KEYBLOB_TOO_SHORT);
 231         goto err;
 232     }
 233
 234     if (isdss)
 235         ret = b2i_dss(&p, bitlen, ispub);
 236     else
 237         ret = b2i_rsa(&p, bitlen, ispub);
 238
 239  err:
 240     OPENSSL_free(buf);
 241     return ret;
 242 }
 243
 244 static EVP_PKEY *b2i_dss(const unsigned char **in,
 245                          unsigned int bitlen, int ispub)
 246 {
 247     const unsigned char *p = *in;
 248     EVP_PKEY *ret = NULL;
 249     DSA *dsa = NULL;
 250     BN_CTX *ctx = NULL;
 251     unsigned int nbyte;
 252     BIGNUM *pbn = NULL, *qbn = NULL, *gbn = NULL, *priv_key = NULL;
 253     BIGNUM *pub_key = NULL;
 254
 255     nbyte = (bitlen + 7) >> 3;
 256
 257     dsa = DSA_new();
 258     ret = EVP_PKEY_new();
 259     if (dsa == NULL || ret == NULL)
 260         goto memerr;
 261     if (!read_lebn(&p, nbyte, &pbn))
 262         goto memerr;
 263
 264     if (!read_lebn(&p, 20, &qbn))
 265         goto memerr;
 266
 267     if (!read_lebn(&p, nbyte, &gbn))
 268         goto memerr;
 269
 270     if (ispub) {
 271         if (!read_lebn(&p, nbyte, &pub_key))
 272             goto memerr;
 273     } else {
 274         if (!read_lebn(&p, 20, &priv_key))
 275             goto memerr;
 276
 277         /* Calculate public key */
 278         pub_key = BN_new();
 279         if (pub_key == NULL)
 280             goto memerr;
 281         if ((ctx = BN_CTX_new()) == NULL)
 282             goto memerr;
 283
 284         if (!BN_mod_exp(pub_key, gbn, priv_key, pbn, ctx))
 285             goto memerr;
 286
 287         BN_CTX_free(ctx);
 288     }
 289     if (!DSA_set0_pqg(dsa, pbn, qbn, gbn))
 290         goto memerr;
 291     pbn = qbn = gbn = NULL;
 292     if (!DSA_set0_key(dsa, pub_key, priv_key))
 293         goto memerr;
 294
 295     EVP_PKEY_set1_DSA(ret, dsa);
 296     DSA_free(dsa);
 297     *in = p;
 298     return ret;
 299
 300  memerr:
 301     PEMerr(PEM_F_B2I_DSS, ERR_R_MALLOC_FAILURE);
 302     DSA_free(dsa);
 303     BN_free(pbn);
 304     BN_free(qbn);
 305     BN_free(gbn);
 306     BN_free(pub_key);
 307     BN_free(priv_key);
 308     EVP_PKEY_free(ret);
 309     BN_CTX_free(ctx);
 310     return NULL;
 311 }
 312
 313 static EVP_PKEY *b2i_rsa(const unsigned char **in,
 314                          unsigned int bitlen, int ispub)
 315 {
 316     const unsigned char *pin = *in;
 317     EVP_PKEY *ret = NULL;
 318     BIGNUM *e = NULL, *n = NULL, *d = NULL;
 319     BIGNUM *p = NULL, *q = NULL, *dmp1 = NULL, *dmq1 = NULL, *iqmp = NULL;
 320     RSA *rsa = NULL;
 321     unsigned int nbyte, hnbyte;
 322     nbyte = (bitlen + 7) >> 3;
 323     hnbyte = (bitlen + 15) >> 4;
 324     rsa = RSA_new();
 325     ret = EVP_PKEY_new();
 326     if (rsa == NULL || ret == NULL)
 327         goto memerr;
 328     e = BN_new();
 329     if (e == NULL)
 330         goto memerr;
 331     if (!BN_set_word(e, read_ledword(&pin)))
 332         goto memerr;
 333     if (!read_lebn(&pin, nbyte, &n))
 334         goto memerr;
 335     if (!ispub) {
 336         if (!read_lebn(&pin, hnbyte, &p))
 337             goto memerr;
 338         if (!read_lebn(&pin, hnbyte, &q))
 339             goto memerr;
 340         if (!read_lebn(&pin, hnbyte, &dmp1))
 341             goto memerr;
 342         if (!read_lebn(&pin, hnbyte, &dmq1))
 343             goto memerr;
 344         if (!read_lebn(&pin, hnbyte, &iqmp))
 345             goto memerr;
 346         if (!read_lebn(&pin, nbyte, &d))
 347             goto memerr;
 348         RSA_set0_factors(rsa, p, q);
 349         RSA_set0_crt_params(rsa, dmp1, dmq1, iqmp);
 350     }
 351     RSA_set0_key(rsa, n, e, d);
 352
 353     EVP_PKEY_set1_RSA(ret, rsa);
 354     RSA_free(rsa);
 355     *in = pin;
 356     return ret;
 357  memerr:
 358     PEMerr(PEM_F_B2I_RSA, ERR_R_MALLOC_FAILURE);
 359     BN_free(e);
 360     BN_free(n);
 361     BN_free(p);
 362     BN_free(q);
 363     BN_free(dmp1);
 364     BN_free(dmq1);
 365     BN_free(iqmp);
 366     BN_free(d);
 367     RSA_free(rsa);
 368     EVP_PKEY_free(ret);
 369     return NULL;
 370 }
 371
 372 EVP_PKEY *b2i_PrivateKey(const unsigned char **in, long length)
 373 {
 374     return do_b2i(in, length, 0);
 375 }
 376
 377 EVP_PKEY *b2i_PublicKey(const unsigned char **in, long length)
 378 {
 379     return do_b2i(in, length, 1);
 380 }
 381
 382 EVP_PKEY *b2i_PrivateKey_bio(BIO *in)
 383 {
 384     return do_b2i_bio(in, 0);
 385 }
 386
 387 EVP_PKEY *b2i_PublicKey_bio(BIO *in)
 388 {
 389     return do_b2i_bio(in, 1);
 390 }
 391
 392 static void write_ledword(unsigned char **out, unsigned int dw)
 393 {
 394     unsigned char *p = *out;
 395     *p++ = dw & 0xff;
 396     *p++ = (dw >> 8) & 0xff;
 397     *p++ = (dw >> 16) & 0xff;
 398     *p++ = (dw >> 24) & 0xff;
 399     *out = p;
 400 }
 401
 402 static void write_lebn(unsigned char **out, const BIGNUM *bn, int len)
 403 {
 404     BN_bn2lebinpad(bn, *out, len);
 405     *out += len;
 406 }
 407
 408 static int check_bitlen_rsa(RSA *rsa, int ispub, unsigned int *magic);
 409 static int check_bitlen_dsa(DSA *dsa, int ispub, unsigned int *magic);
 410
 411 static void write_rsa(unsigned char **out, RSA *rsa, int ispub);
 412 static void write_dsa(unsigned char **out, DSA *dsa, int ispub);
 413
 414 static int do_i2b(unsigned char **out, EVP_PKEY *pk, int ispub)
 415 {
 416     unsigned char *p;
 417     unsigned int bitlen, magic = 0, keyalg;
 418     int outlen, noinc = 0;
 419     int pktype = EVP_PKEY_id(pk);
 420     if (pktype == EVP_PKEY_DSA) {
 421         bitlen = check_bitlen_dsa(EVP_PKEY_get0_DSA(pk), ispub, &magic);
 422         keyalg = MS_KEYALG_DSS_SIGN;
 423     } else if (pktype == EVP_PKEY_RSA) {
 424         bitlen = check_bitlen_rsa(EVP_PKEY_get0_RSA(pk), ispub, &magic);
 425         keyalg = MS_KEYALG_RSA_KEYX;
 426     } else
 427         return -1;
 428     if (bitlen == 0)
 429         return -1;
 430     outlen = 16 + blob_length(bitlen,
 431                               keyalg == MS_KEYALG_DSS_SIGN ? 1 : 0, ispub);
 432     if (out == NULL)
 433         return outlen;
 434     if (*out)
 435         p = *out;
 436     else {
 437         p = OPENSSL_malloc(outlen);
 438         if (p == NULL)
 439             return -1;
 440         *out = p;
 441         noinc = 1;
 442     }
 443     if (ispub)
 444         *p++ = MS_PUBLICKEYBLOB;
 445     else
 446         *p++ = MS_PRIVATEKEYBLOB;
 447     *p++ = 0x2;
 448     *p++ = 0;
 449     *p++ = 0;
 450     write_ledword(&p, keyalg);
 451     write_ledword(&p, magic);
 452     write_ledword(&p, bitlen);
 453     if (keyalg == MS_KEYALG_DSS_SIGN)
 454         write_dsa(&p, EVP_PKEY_get0_DSA(pk), ispub);
 455     else
 456         write_rsa(&p, EVP_PKEY_get0_RSA(pk), ispub);
 457     if (!noinc)
 458         *out += outlen;
 459     return outlen;
 460 }
 461
 462 static int do_i2b_bio(BIO *out, EVP_PKEY *pk, int ispub)
 463 {
 464     unsigned char *tmp = NULL;
 465     int outlen, wrlen;
 466     outlen = do_i2b(&tmp, pk, ispub);
 467     if (outlen < 0)
 468         return -1;
 469     wrlen = BIO_write(out, tmp, outlen);
 470     OPENSSL_free(tmp);
 471     if (wrlen == outlen)
 472         return outlen;
 473     return -1;
 474 }
 475
 476 static int check_bitlen_dsa(DSA *dsa, int ispub, unsigned int *pmagic)
 477 {
 478     int bitlen;
 479     const BIGNUM *p = NULL, *q = NULL, *g = NULL;
 480     const BIGNUM *pub_key = NULL, *priv_key = NULL;
 481
 482     DSA_get0_pqg(dsa, &p, &q, &g);
 483     DSA_get0_key(dsa, &pub_key, &priv_key);
 484     bitlen = BN_num_bits(p);
 485     if ((bitlen & 7) || (BN_num_bits(q) != 160)
 486         || (BN_num_bits(g) > bitlen))
 487         goto badkey;
 488     if (ispub) {
 489         if (BN_num_bits(pub_key) > bitlen)
 490             goto badkey;
 491         *pmagic = MS_DSS1MAGIC;
 492     } else {
 493         if (BN_num_bits(priv_key) > 160)
 494             goto badkey;
 495         *pmagic = MS_DSS2MAGIC;
 496     }
 497
 498     return bitlen;
 499  badkey:
 500     PEMerr(PEM_F_CHECK_BITLEN_DSA, PEM_R_UNSUPPORTED_KEY_COMPONENTS);
 501     return 0;
 502 }
 503
 504 static int check_bitlen_rsa(RSA *rsa, int ispub, unsigned int *pmagic)
 505 {
 506     int nbyte, hnbyte, bitlen;
 507     const BIGNUM *e;
 508
 509     RSA_get0_key(rsa, NULL, &e, NULL);
 510     if (BN_num_bits(e) > 32)
 511         goto badkey;
 512     bitlen = RSA_bits(rsa);
 513     nbyte = RSA_size(rsa);
 514     hnbyte = (bitlen + 15) >> 4;
 515     if (ispub) {
 516         *pmagic = MS_RSA1MAGIC;
 517         return bitlen;
 518     } else {
 519         const BIGNUM *d, *p, *q, *iqmp, *dmp1, *dmq1;
 520
 521         *pmagic = MS_RSA2MAGIC;
 522
 523         /*
 524          * For private key each component must fit within nbyte or hnbyte.
 525          */
 526         RSA_get0_key(rsa, NULL, NULL, &d);
 527         if (BN_num_bytes(d) > nbyte)
 528             goto badkey;
 529         RSA_get0_factors(rsa, &p, &q);
 530         RSA_get0_crt_params(rsa, &dmp1, &dmq1, &iqmp);
 531         if ((BN_num_bytes(iqmp) > hnbyte)
 532             || (BN_num_bytes(p) > hnbyte)
 533             || (BN_num_bytes(q) > hnbyte)
 534             || (BN_num_bytes(dmp1) > hnbyte)
 535             || (BN_num_bytes(dmq1) > hnbyte))
 536             goto badkey;
 537     }
 538     return bitlen;
 539  badkey:
 540     PEMerr(PEM_F_CHECK_BITLEN_RSA, PEM_R_UNSUPPORTED_KEY_COMPONENTS);
 541     return 0;
 542 }
 543
 544 static void write_rsa(unsigned char **out, RSA *rsa, int ispub)
 545 {
 546     int nbyte, hnbyte;
 547     const BIGNUM *n, *d, *e, *p, *q, *iqmp, *dmp1, *dmq1;
 548
 549     nbyte = RSA_size(rsa);
 550     hnbyte = (RSA_bits(rsa) + 15) >> 4;
 551     RSA_get0_key(rsa, &n, &e, &d);
 552     write_lebn(out, e, 4);
 553     write_lebn(out, n, nbyte);
 554     if (ispub)
 555         return;
 556     RSA_get0_factors(rsa, &p, &q);
 557     RSA_get0_crt_params(rsa, &dmp1, &dmq1, &iqmp);
 558     write_lebn(out, p, hnbyte);
 559     write_lebn(out, q, hnbyte);
 560     write_lebn(out, dmp1, hnbyte);
 561     write_lebn(out, dmq1, hnbyte);
 562     write_lebn(out, iqmp, hnbyte);
 563     write_lebn(out, d, nbyte);
 564 }
 565
 566 static void write_dsa(unsigned char **out, DSA *dsa, int ispub)
 567 {
 568     int nbyte;
 569     const BIGNUM *p = NULL, *q = NULL, *g = NULL;
 570     const BIGNUM *pub_key = NULL, *priv_key = NULL;
 571
 572     DSA_get0_pqg(dsa, &p, &q, &g);
 573     DSA_get0_key(dsa, &pub_key, &priv_key);
 574     nbyte = BN_num_bytes(p);
 575     write_lebn(out, p, nbyte);
 576     write_lebn(out, q, 20);
 577     write_lebn(out, g, nbyte);
 578     if (ispub)
 579         write_lebn(out, pub_key, nbyte);
 580     else
 581         write_lebn(out, priv_key, 20);
 582     /* Set "invalid" for seed structure values */
 583     memset(*out, 0xff, 24);
 584     *out += 24;
 585     return;
 586 }
 587
 588 int i2b_PrivateKey_bio(BIO *out, EVP_PKEY *pk)
 589 {
 590     return do_i2b_bio(out, pk, 0);
 591 }
 592
 593 int i2b_PublicKey_bio(BIO *out, EVP_PKEY *pk)
 594 {
 595     return do_i2b_bio(out, pk, 1);
 596 }
 597
 598 # ifndef OPENSSL_NO_RC4
 599
 600 static int do_PVK_header(const unsigned char **in, unsigned int length,
 601                          int skip_magic,
 602                          unsigned int *psaltlen, unsigned int *pkeylen)
 603 {
 604     const unsigned char *p = *in;
 605     unsigned int pvk_magic, is_encrypted;
 606     if (skip_magic) {
 607         if (length < 20) {
 608             PEMerr(PEM_F_DO_PVK_HEADER, PEM_R_PVK_TOO_SHORT);
 609             return 0;
 610         }
 611     } else {
 612         if (length < 24) {
 613             PEMerr(PEM_F_DO_PVK_HEADER, PEM_R_PVK_TOO_SHORT);
 614             return 0;
 615         }
 616         pvk_magic = read_ledword(&p);
 617         if (pvk_magic != MS_PVKMAGIC) {
 618             PEMerr(PEM_F_DO_PVK_HEADER, PEM_R_BAD_MAGIC_NUMBER);
 619             return 0;
 620         }
 621     }
 622     /* Skip reserved */
 623     p += 4;
 624     /*
 625      * keytype =
 626      */ read_ledword(&p);
 627     is_encrypted = read_ledword(&p);
 628     *psaltlen = read_ledword(&p);
 629     *pkeylen = read_ledword(&p);
 630
 631     if (*pkeylen > PVK_MAX_KEYLEN || *psaltlen > PVK_MAX_SALTLEN)
 632         return 0;
 633
 634     if (is_encrypted && !*psaltlen) {
 635         PEMerr(PEM_F_DO_PVK_HEADER, PEM_R_INCONSISTENT_HEADER);
 636         return 0;
 637     }
 638
 639     *in = p;
 640     return 1;
 641 }
 642
 643 static int derive_pvk_key(unsigned char *key,
 644                           const unsigned char *salt, unsigned int saltlen,
 645                           const unsigned char *pass, int passlen)
 646 {
 647     EVP_MD_CTX *mctx = EVP_MD_CTX_new();
 648     int rv = 1;
 649     if (mctx == NULL
 650         || !EVP_DigestInit_ex(mctx, EVP_sha1(), NULL)
 651         || !EVP_DigestUpdate(mctx, salt, saltlen)
 652         || !EVP_DigestUpdate(mctx, pass, passlen)
 653         || !EVP_DigestFinal_ex(mctx, key, NULL))
 654         rv = 0;
 655
 656     EVP_MD_CTX_free(mctx);
 657     return rv;
 658 }
 659
 660 static EVP_PKEY *do_PVK_body(const unsigned char **in,
 661                              unsigned int saltlen, unsigned int keylen,
 662                              pem_password_cb *cb, void *u)
 663 {
 664     EVP_PKEY *ret = NULL;
 665     const unsigned char *p = *in;
 666     unsigned int magic;
 667     unsigned char *enctmp = NULL, *q;
 668
 669     EVP_CIPHER_CTX *cctx = EVP_CIPHER_CTX_new();
 670     if (saltlen) {
 671         char psbuf[PEM_BUFSIZE];
 672         unsigned char keybuf[20];
 673         int enctmplen, inlen;
 674         if (cb)
 675             inlen = cb(psbuf, PEM_BUFSIZE, 0, u);
 676         else
 677             inlen = PEM_def_callback(psbuf, PEM_BUFSIZE, 0, u);
 678         if (inlen <= 0) {
 679             PEMerr(PEM_F_DO_PVK_BODY, PEM_R_BAD_PASSWORD_READ);
 680             goto err;
 681         }
 682         enctmp = OPENSSL_malloc(keylen + 8);
 683         if (enctmp == NULL) {
 684             PEMerr(PEM_F_DO_PVK_BODY, ERR_R_MALLOC_FAILURE);
 685             goto err;
 686         }
 687         if (!derive_pvk_key(keybuf, p, saltlen,
 688                             (unsigned char *)psbuf, inlen))
 689             goto err;
 690         p += saltlen;
 691         /* Copy BLOBHEADER across, decrypt rest */
 692         memcpy(enctmp, p, 8);
 693         p += 8;
 694         if (keylen < 8) {
 695             PEMerr(PEM_F_DO_PVK_BODY, PEM_R_PVK_TOO_SHORT);
 696             goto err;
 697         }
 698         inlen = keylen - 8;
 699         q = enctmp + 8;
 700         if (!EVP_DecryptInit_ex(cctx, EVP_rc4(), NULL, keybuf, NULL))
 701             goto err;
 702         if (!EVP_DecryptUpdate(cctx, q, &enctmplen, p, inlen))
 703             goto err;
 704         if (!EVP_DecryptFinal_ex(cctx, q + enctmplen, &enctmplen))
 705             goto err;
 706         magic = read_ledword((const unsigned char **)&q);
 707         if (magic != MS_RSA2MAGIC && magic != MS_DSS2MAGIC) {
 708             q = enctmp + 8;
 709             memset(keybuf + 5, 0, 11);
 710             if (!EVP_DecryptInit_ex(cctx, EVP_rc4(), NULL, keybuf, NULL))
 711                 goto err;
 712             OPENSSL_cleanse(keybuf, 20);
 713             if (!EVP_DecryptUpdate(cctx, q, &enctmplen, p, inlen))
 714                 goto err;
 715             if (!EVP_DecryptFinal_ex(cctx, q + enctmplen, &enctmplen))
 716                 goto err;
 717             magic = read_ledword((const unsigned char **)&q);
 718             if (magic != MS_RSA2MAGIC && magic != MS_DSS2MAGIC) {
 719                 PEMerr(PEM_F_DO_PVK_BODY, PEM_R_BAD_DECRYPT);
 720                 goto err;
 721             }
 722         } else
 723             OPENSSL_cleanse(keybuf, 20);
 724         p = enctmp;
 725     }
 726
 727     ret = b2i_PrivateKey(&p, keylen);
 728  err:
 729     EVP_CIPHER_CTX_free(cctx);
 730     OPENSSL_free(enctmp);
 731     return ret;
 732 }
 733
 734 EVP_PKEY *b2i_PVK_bio(BIO *in, pem_password_cb *cb, void *u)
 735 {
 736     unsigned char pvk_hdr[24], *buf = NULL;
 737     const unsigned char *p;
 738     int buflen;
 739     EVP_PKEY *ret = NULL;
 740     unsigned int saltlen, keylen;
 741     if (BIO_read(in, pvk_hdr, 24) != 24) {
 742         PEMerr(PEM_F_B2I_PVK_BIO, PEM_R_PVK_DATA_TOO_SHORT);
 743         return NULL;
 744     }
 745     p = pvk_hdr;
 746
 747     if (!do_PVK_header(&p, 24, 0, &saltlen, &keylen))
 748         return 0;
 749     buflen = (int)keylen + saltlen;
 750     buf = OPENSSL_malloc(buflen);
 751     if (buf == NULL) {
 752         PEMerr(PEM_F_B2I_PVK_BIO, ERR_R_MALLOC_FAILURE);
 753         return 0;
 754     }
 755     p = buf;
 756     if (BIO_read(in, buf, buflen) != buflen) {
 757         PEMerr(PEM_F_B2I_PVK_BIO, PEM_R_PVK_DATA_TOO_SHORT);
 758         goto err;
 759     }
 760     ret = do_PVK_body(&p, saltlen, keylen, cb, u);
 761
 762  err:
 763     OPENSSL_clear_free(buf, buflen);
 764     return ret;
 765 }
 766
 767 static int i2b_PVK(unsigned char **out, EVP_PKEY *pk, int enclevel,
 768                    pem_password_cb *cb, void *u)
 769 {
 770     int outlen = 24, pklen;
 771     unsigned char *p = NULL, *start = NULL, *salt = NULL;
 772     EVP_CIPHER_CTX *cctx = NULL;
 773     if (enclevel)
 774         outlen += PVK_SALTLEN;
 775     pklen = do_i2b(NULL, pk, 0);
 776     if (pklen < 0)
 777         return -1;
 778     outlen += pklen;
 779     if (out == NULL)
 780         return outlen;
 781     if (*out != NULL) {
 782         p = *out;
 783     } else {
 784         start = p = OPENSSL_malloc(outlen);
 785         if (p == NULL) {
 786             PEMerr(PEM_F_I2B_PVK, ERR_R_MALLOC_FAILURE);
 787             return -1;
 788         }
 789     }
 790
 791     cctx = EVP_CIPHER_CTX_new();
 792     if (cctx == NULL)
 793         goto error;
 794
 795     write_ledword(&p, MS_PVKMAGIC);
 796     write_ledword(&p, 0);
 797     if (EVP_PKEY_id(pk) == EVP_PKEY_DSA)
 798         write_ledword(&p, MS_KEYTYPE_SIGN);
 799     else
 800         write_ledword(&p, MS_KEYTYPE_KEYX);
 801     write_ledword(&p, enclevel ? 1 : 0);
 802     write_ledword(&p, enclevel ? PVK_SALTLEN : 0);
 803     write_ledword(&p, pklen);
 804     if (enclevel) {
 805         if (RAND_bytes(p, PVK_SALTLEN) <= 0)
 806             goto error;
 807         salt = p;
 808         p += PVK_SALTLEN;
 809     }
 810     do_i2b(&p, pk, 0);
 811     if (enclevel != 0) {
 812         char psbuf[PEM_BUFSIZE];
 813         unsigned char keybuf[20];
 814         int enctmplen, inlen;
 815         if (cb)
 816             inlen = cb(psbuf, PEM_BUFSIZE, 1, u);
 817         else
 818             inlen = PEM_def_callback(psbuf, PEM_BUFSIZE, 1, u);
 819         if (inlen <= 0) {
 820             PEMerr(PEM_F_I2B_PVK, PEM_R_BAD_PASSWORD_READ);
 821             goto error;
 822         }
 823         if (!derive_pvk_key(keybuf, salt, PVK_SALTLEN,
 824                             (unsigned char *)psbuf, inlen))
 825             goto error;
 826         if (enclevel == 1)
 827             memset(keybuf + 5, 0, 11);
 828         p = salt + PVK_SALTLEN + 8;
 829         if (!EVP_EncryptInit_ex(cctx, EVP_rc4(), NULL, keybuf, NULL))
 830             goto error;
 831         OPENSSL_cleanse(keybuf, 20);
 832         if (!EVP_DecryptUpdate(cctx, p, &enctmplen, p, pklen - 8))
 833             goto error;
 834         if (!EVP_DecryptFinal_ex(cctx, p + enctmplen, &enctmplen))
 835             goto error;
 836     }
 837
 838     EVP_CIPHER_CTX_free(cctx);
 839
 840     if (*out == NULL)
 841         *out = start;
 842
 843     return outlen;
 844
 845  error:
 846     EVP_CIPHER_CTX_free(cctx);
 847     if (*out == NULL)
 848         OPENSSL_free(start);
 849     return -1;
 850 }
 851
 852 int i2b_PVK_bio(BIO *out, EVP_PKEY *pk, int enclevel,
 853                 pem_password_cb *cb, void *u)
 854 {
 855     unsigned char *tmp = NULL;
 856     int outlen, wrlen;
 857     outlen = i2b_PVK(&tmp, pk, enclevel, cb, u);
 858     if (outlen < 0)
 859         return -1;
 860     wrlen = BIO_write(out, tmp, outlen);
 861     OPENSSL_free(tmp);
 862     if (wrlen == outlen) {
 863         PEMerr(PEM_F_I2B_PVK_BIO, PEM_R_BIO_WRITE_FAILURE);
 864         return outlen;
 865     }
 866     return -1;
 867 }
 868
 869 # endif
 870
 871 #endif