crypto/pem/pem_lib.c

   1 /*
   2  * Copyright 1995-2016 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 #include <stdio.h>
  11 #include <ctype.h>
  12 #include <string.h>
  13 #include "internal/cryptlib.h"
  14 #include <openssl/buffer.h>
  15 #include <openssl/objects.h>
  16 #include <openssl/evp.h>
  17 #include <openssl/rand.h>
  18 #include <openssl/x509.h>
  19 #include <openssl/pem.h>
  20 #include <openssl/pkcs12.h>
  21 #include "internal/asn1_int.h"
  22 #include <openssl/des.h>
  23 #include <openssl/engine.h>
  24
  25 #define MIN_LENGTH      4
  26
  27 static int load_iv(char **fromp, unsigned char *to, int num);
  28 static int check_pem(const char *nm, const char *name);
  29 int pem_check_suffix(const char *pem_str, const char *suffix);
  30
  31 int PEM_def_callback(char *buf, int num, int w, void *key)
  32 {
  33     int i, j;
  34     const char *prompt;
  35
  36     if (key) {
  37         i = strlen(key);
  38         i = (i > num) ? num : i;
  39         memcpy(buf, key, i);
  40         return i;
  41     }
  42
  43     prompt = EVP_get_pw_prompt();
  44     if (prompt == NULL)
  45         prompt = "Enter PEM pass phrase:";
  46
  47     for (;;) {
  48         /*
  49          * We assume that w == 0 means decryption,
  50          * while w == 1 means encryption
  51          */
  52         int min_len = w ? MIN_LENGTH : 0;
  53
  54         i = EVP_read_pw_string_min(buf, min_len, num, prompt, w);
  55         if (i != 0) {
  56             PEMerr(PEM_F_PEM_DEF_CALLBACK, PEM_R_PROBLEMS_GETTING_PASSWORD);
  57             memset(buf, 0, (unsigned int)num);
  58             return -1;
  59         }
  60         j = strlen(buf);
  61         if (min_len && j < min_len) {
  62             fprintf(stderr,
  63                     "phrase is too short, needs to be at least %d chars\n",
  64                     min_len);
  65         } else
  66             break;
  67     }
  68     return j;
  69 }
  70
  71 void PEM_proc_type(char *buf, int type)
  72 {
  73     const char *str;
  74
  75     if (type == PEM_TYPE_ENCRYPTED)
  76         str = "ENCRYPTED";
  77     else if (type == PEM_TYPE_MIC_CLEAR)
  78         str = "MIC-CLEAR";
  79     else if (type == PEM_TYPE_MIC_ONLY)
  80         str = "MIC-ONLY";
  81     else
  82         str = "BAD-TYPE";
  83
  84     OPENSSL_strlcat(buf, "Proc-Type: 4,", PEM_BUFSIZE);
  85     OPENSSL_strlcat(buf, str, PEM_BUFSIZE);
  86     OPENSSL_strlcat(buf, "\n", PEM_BUFSIZE);
  87 }
  88
  89 void PEM_dek_info(char *buf, const char *type, int len, char *str)
  90 {
  91     static const unsigned char map[17] = "0123456789ABCDEF";
  92     long i;
  93     int j;
  94
  95     OPENSSL_strlcat(buf, "DEK-Info: ", PEM_BUFSIZE);
  96     OPENSSL_strlcat(buf, type, PEM_BUFSIZE);
  97     OPENSSL_strlcat(buf, ",", PEM_BUFSIZE);
  98     j = strlen(buf);
  99     if (j + (len * 2) + 1 > PEM_BUFSIZE)
 100         return;
 101     for (i = 0; i < len; i++) {
 102         buf[j + i * 2] = map[(str[i] >> 4) & 0x0f];
 103         buf[j + i * 2 + 1] = map[(str[i]) & 0x0f];
 104     }
 105     buf[j + i * 2] = '\n';
 106     buf[j + i * 2 + 1] = '\0';
 107 }
 108
 109 #ifndef OPENSSL_NO_STDIO
 110 void *PEM_ASN1_read(d2i_of_void *d2i, const char *name, FILE *fp, void **x,
 111                     pem_password_cb *cb, void *u)
 112 {
 113     BIO *b;
 114     void *ret;
 115
 116     if ((b = BIO_new(BIO_s_file())) == NULL) {
 117         PEMerr(PEM_F_PEM_ASN1_READ, ERR_R_BUF_LIB);
 118         return (0);
 119     }
 120     BIO_set_fp(b, fp, BIO_NOCLOSE);
 121     ret = PEM_ASN1_read_bio(d2i, name, b, x, cb, u);
 122     BIO_free(b);
 123     return (ret);
 124 }
 125 #endif
 126
 127 static int check_pem(const char *nm, const char *name)
 128 {
 129     /* Normal matching nm and name */
 130     if (strcmp(nm, name) == 0)
 131         return 1;
 132
 133     /* Make PEM_STRING_EVP_PKEY match any private key */
 134
 135     if (strcmp(name, PEM_STRING_EVP_PKEY) == 0) {
 136         int slen;
 137         const EVP_PKEY_ASN1_METHOD *ameth;
 138         if (strcmp(nm, PEM_STRING_PKCS8) == 0)
 139             return 1;
 140         if (strcmp(nm, PEM_STRING_PKCS8INF) == 0)
 141             return 1;
 142         slen = pem_check_suffix(nm, "PRIVATE KEY");
 143         if (slen > 0) {
 144             /*
 145              * NB: ENGINE implementations won't contain a deprecated old
 146              * private key decode function so don't look for them.
 147              */
 148             ameth = EVP_PKEY_asn1_find_str(NULL, nm, slen);
 149             if (ameth && ameth->old_priv_decode)
 150                 return 1;
 151         }
 152         return 0;
 153     }
 154
 155     if (strcmp(name, PEM_STRING_PARAMETERS) == 0) {
 156         int slen;
 157         const EVP_PKEY_ASN1_METHOD *ameth;
 158         slen = pem_check_suffix(nm, "PARAMETERS");
 159         if (slen > 0) {
 160             ENGINE *e;
 161             ameth = EVP_PKEY_asn1_find_str(&e, nm, slen);
 162             if (ameth) {
 163                 int r;
 164                 if (ameth->param_decode)
 165                     r = 1;
 166                 else
 167                     r = 0;
 168 #ifndef OPENSSL_NO_ENGINE
 169                 ENGINE_finish(e);
 170 #endif
 171                 return r;
 172             }
 173         }
 174         return 0;
 175     }
 176     /* If reading DH parameters handle X9.42 DH format too */
 177     if (strcmp(nm, PEM_STRING_DHXPARAMS) == 0
 178         && strcmp(name, PEM_STRING_DHPARAMS) == 0)
 179         return 1;
 180
 181     /* Permit older strings */
 182
 183     if (strcmp(nm, PEM_STRING_X509_OLD) == 0
 184         && strcmp(name, PEM_STRING_X509) == 0)
 185         return 1;
 186
 187     if (strcmp(nm, PEM_STRING_X509_REQ_OLD) == 0
 188         && strcmp(name, PEM_STRING_X509_REQ) == 0)
 189         return 1;
 190
 191     /* Allow normal certs to be read as trusted certs */
 192     if (strcmp(nm, PEM_STRING_X509) == 0
 193         && strcmp(name, PEM_STRING_X509_TRUSTED) == 0)
 194         return 1;
 195
 196     if (strcmp(nm, PEM_STRING_X509_OLD) == 0
 197         && strcmp(name, PEM_STRING_X509_TRUSTED) == 0)
 198         return 1;
 199
 200     /* Some CAs use PKCS#7 with CERTIFICATE headers */
 201     if (strcmp(nm, PEM_STRING_X509) == 0
 202         && strcmp(name, PEM_STRING_PKCS7) == 0)
 203         return 1;
 204
 205     if (strcmp(nm, PEM_STRING_PKCS7_SIGNED) == 0
 206         && strcmp(name, PEM_STRING_PKCS7) == 0)
 207         return 1;
 208
 209 #ifndef OPENSSL_NO_CMS
 210     if (strcmp(nm, PEM_STRING_X509) == 0
 211         && strcmp(name, PEM_STRING_CMS) == 0)
 212         return 1;
 213     /* Allow CMS to be read from PKCS#7 headers */
 214     if (strcmp(nm, PEM_STRING_PKCS7) == 0
 215         && strcmp(name, PEM_STRING_CMS) == 0)
 216         return 1;
 217 #endif
 218
 219     return 0;
 220 }
 221
 222 static void pem_free(void *p, unsigned int flags)
 223 {
 224     if (flags & PEM_FLAG_SECURE)
 225         OPENSSL_secure_free(p);
 226     else
 227         OPENSSL_free(p);
 228 }
 229
 230 static void *pem_malloc(int num, unsigned int flags)
 231 {
 232     return (flags & PEM_FLAG_SECURE) ? OPENSSL_secure_malloc(num)
 233                                      : OPENSSL_malloc(num);
 234 }
 235
 236 static int pem_bytes_read_bio_flags(unsigned char **pdata, long *plen,
 237                                     char **pnm, const char *name, BIO *bp,
 238                                     pem_password_cb *cb, void *u,
 239                                     unsigned int flags)
 240 {
 241     EVP_CIPHER_INFO cipher;
 242     char *nm = NULL, *header = NULL;
 243     unsigned char *data = NULL;
 244     long len;
 245     int ret = 0;
 246
 247     do {
 248         pem_free(nm, flags);
 249         pem_free(header, flags);
 250         pem_free(data, flags);
 251         if (!PEM_read_bio_ex(bp, &nm, &header, &data, &len, flags)) {
 252             if (ERR_GET_REASON(ERR_peek_error()) == PEM_R_NO_START_LINE)
 253                 ERR_add_error_data(2, "Expecting: ", name);
 254             return 0;
 255         }
 256     } while (!check_pem(nm, name));
 257     if (!PEM_get_EVP_CIPHER_INFO(header, &cipher))
 258         goto err;
 259     if (!PEM_do_header(&cipher, data, &len, cb, u))
 260         goto err;
 261
 262     *pdata = data;
 263     *plen = len;
 264
 265     if (pnm != NULL)
 266         *pnm = nm;
 267
 268     ret = 1;
 269
 270  err:
 271     if (!ret || pnm == NULL)
 272         pem_free(nm, flags);
 273     pem_free(header, flags);
 274     if (!ret)
 275         pem_free(data, flags);
 276     return ret;
 277 }
 278
 279 int PEM_bytes_read_bio(unsigned char **pdata, long *plen, char **pnm,
 280                        const char *name, BIO *bp, pem_password_cb *cb,
 281                        void *u) {
 282     return pem_bytes_read_bio_flags(pdata, plen, pnm, name, bp, cb, u,
 283                                     PEM_FLAG_EAY_COMPATIBLE);
 284 }
 285
 286 int PEM_bytes_read_bio_secmem(unsigned char **pdata, long *plen, char **pnm,
 287                               const char *name, BIO *bp, pem_password_cb *cb,
 288                               void *u) {
 289     return pem_bytes_read_bio_flags(pdata, plen, pnm, name, bp, cb, u,
 290                                     PEM_FLAG_SECURE | PEM_FLAG_EAY_COMPATIBLE);
 291 }
 292
 293 #ifndef OPENSSL_NO_STDIO
 294 int PEM_ASN1_write(i2d_of_void *i2d, const char *name, FILE *fp,
 295                    void *x, const EVP_CIPHER *enc, unsigned char *kstr,
 296                    int klen, pem_password_cb *callback, void *u)
 297 {
 298     BIO *b;
 299     int ret;
 300
 301     if ((b = BIO_new(BIO_s_file())) == NULL) {
 302         PEMerr(PEM_F_PEM_ASN1_WRITE, ERR_R_BUF_LIB);
 303         return (0);
 304     }
 305     BIO_set_fp(b, fp, BIO_NOCLOSE);
 306     ret = PEM_ASN1_write_bio(i2d, name, b, x, enc, kstr, klen, callback, u);
 307     BIO_free(b);
 308     return (ret);
 309 }
 310 #endif
 311
 312 int PEM_ASN1_write_bio(i2d_of_void *i2d, const char *name, BIO *bp,
 313                        void *x, const EVP_CIPHER *enc, unsigned char *kstr,
 314                        int klen, pem_password_cb *callback, void *u)
 315 {
 316     EVP_CIPHER_CTX *ctx = NULL;
 317     int dsize = 0, i = 0, j = 0, ret = 0;
 318     unsigned char *p, *data = NULL;
 319     const char *objstr = NULL;
 320     char buf[PEM_BUFSIZE];
 321     unsigned char key[EVP_MAX_KEY_LENGTH];
 322     unsigned char iv[EVP_MAX_IV_LENGTH];
 323
 324     if (enc != NULL) {
 325         objstr = OBJ_nid2sn(EVP_CIPHER_nid(enc));
 326         if (objstr == NULL || EVP_CIPHER_iv_length(enc) == 0) {
 327             PEMerr(PEM_F_PEM_ASN1_WRITE_BIO, PEM_R_UNSUPPORTED_CIPHER);
 328             goto err;
 329         }
 330     }
 331
 332     if ((dsize = i2d(x, NULL)) < 0) {
 333         PEMerr(PEM_F_PEM_ASN1_WRITE_BIO, ERR_R_ASN1_LIB);
 334         dsize = 0;
 335         goto err;
 336     }
 337     /* dsize + 8 bytes are needed */
 338     /* actually it needs the cipher block size extra... */
 339     data = OPENSSL_malloc((unsigned int)dsize + 20);
 340     if (data == NULL) {
 341         PEMerr(PEM_F_PEM_ASN1_WRITE_BIO, ERR_R_MALLOC_FAILURE);
 342         goto err;
 343     }
 344     p = data;
 345     i = i2d(x, &p);
 346
 347     if (enc != NULL) {
 348         if (kstr == NULL) {
 349             if (callback == NULL)
 350                 klen = PEM_def_callback(buf, PEM_BUFSIZE, 1, u);
 351             else
 352                 klen = (*callback) (buf, PEM_BUFSIZE, 1, u);
 353             if (klen <= 0) {
 354                 PEMerr(PEM_F_PEM_ASN1_WRITE_BIO, PEM_R_READ_KEY);
 355                 goto err;
 356             }
 357 #ifdef CHARSET_EBCDIC
 358             /* Convert the pass phrase from EBCDIC */
 359             ebcdic2ascii(buf, buf, klen);
 360 #endif
 361             kstr = (unsigned char *)buf;
 362         }
 363         RAND_add(data, i, 0);   /* put in the RSA key. */
 364         OPENSSL_assert(EVP_CIPHER_iv_length(enc) <= (int)sizeof(iv));
 365         if (RAND_bytes(iv, EVP_CIPHER_iv_length(enc)) <= 0) /* Generate a salt */
 366             goto err;
 367         /*
 368          * The 'iv' is used as the iv and as a salt.  It is NOT taken from
 369          * the BytesToKey function
 370          */
 371         if (!EVP_BytesToKey(enc, EVP_md5(), iv, kstr, klen, 1, key, NULL))
 372             goto err;
 373
 374         if (kstr == (unsigned char *)buf)
 375             OPENSSL_cleanse(buf, PEM_BUFSIZE);
 376
 377         OPENSSL_assert(strlen(objstr) + 23 + 2 * EVP_CIPHER_iv_length(enc) + 13
 378                        <= sizeof buf);
 379
 380         buf[0] = '\0';
 381         PEM_proc_type(buf, PEM_TYPE_ENCRYPTED);
 382         PEM_dek_info(buf, objstr, EVP_CIPHER_iv_length(enc), (char *)iv);
 383         /* k=strlen(buf); */
 384
 385         ret = 1;
 386         if ((ctx = EVP_CIPHER_CTX_new()) == NULL
 387             || !EVP_EncryptInit_ex(ctx, enc, NULL, key, iv)
 388             || !EVP_EncryptUpdate(ctx, data, &j, data, i)
 389             || !EVP_EncryptFinal_ex(ctx, &(data[j]), &i))
 390             ret = 0;
 391         if (ret == 0)
 392             goto err;
 393         i += j;
 394     } else {
 395         ret = 1;
 396         buf[0] = '\0';
 397     }
 398     i = PEM_write_bio(bp, name, buf, data, i);
 399     if (i <= 0)
 400         ret = 0;
 401  err:
 402     OPENSSL_cleanse(key, sizeof(key));
 403     OPENSSL_cleanse(iv, sizeof(iv));
 404     EVP_CIPHER_CTX_free(ctx);
 405     OPENSSL_cleanse(buf, PEM_BUFSIZE);
 406     OPENSSL_clear_free(data, (unsigned int)dsize);
 407     return (ret);
 408 }
 409
 410 int PEM_do_header(EVP_CIPHER_INFO *cipher, unsigned char *data, long *plen,
 411                   pem_password_cb *callback, void *u)
 412 {
 413     int ok;
 414     int keylen;
 415     long len = *plen;
 416     int ilen = (int) len;       /* EVP_DecryptUpdate etc. take int lengths */
 417     EVP_CIPHER_CTX *ctx;
 418     unsigned char key[EVP_MAX_KEY_LENGTH];
 419     char buf[PEM_BUFSIZE];
 420
 421 #if LONG_MAX > INT_MAX
 422     /* Check that we did not truncate the length */
 423     if (len > INT_MAX) {
 424         PEMerr(PEM_F_PEM_DO_HEADER, PEM_R_HEADER_TOO_LONG);
 425         return 0;
 426     }
 427 #endif
 428
 429     if (cipher->cipher == NULL)
 430         return 1;
 431     if (callback == NULL)
 432         keylen = PEM_def_callback(buf, PEM_BUFSIZE, 0, u);
 433     else
 434         keylen = callback(buf, PEM_BUFSIZE, 0, u);
 435     if (keylen <= 0) {
 436         PEMerr(PEM_F_PEM_DO_HEADER, PEM_R_BAD_PASSWORD_READ);
 437         return 0;
 438     }
 439 #ifdef CHARSET_EBCDIC
 440     /* Convert the pass phrase from EBCDIC */
 441     ebcdic2ascii(buf, buf, keylen);
 442 #endif
 443
 444     if (!EVP_BytesToKey(cipher->cipher, EVP_md5(), &(cipher->iv[0]),
 445                         (unsigned char *)buf, keylen, 1, key, NULL))
 446         return 0;
 447
 448     ctx = EVP_CIPHER_CTX_new();
 449     if (ctx == NULL)
 450         return 0;
 451
 452     ok = EVP_DecryptInit_ex(ctx, cipher->cipher, NULL, key, &(cipher->iv[0]));
 453     if (ok)
 454         ok = EVP_DecryptUpdate(ctx, data, &ilen, data, ilen);
 455     if (ok) {
 456         /* Squirrel away the length of data decrypted so far. */
 457         *plen = ilen;
 458         ok = EVP_DecryptFinal_ex(ctx, &(data[ilen]), &ilen);
 459     }
 460     if (ok)
 461         *plen += ilen;
 462     else
 463         PEMerr(PEM_F_PEM_DO_HEADER, PEM_R_BAD_DECRYPT);
 464
 465     EVP_CIPHER_CTX_free(ctx);
 466     OPENSSL_cleanse((char *)buf, sizeof(buf));
 467     OPENSSL_cleanse((char *)key, sizeof(key));
 468     return ok;
 469 }
 470
 471 /*
 472  * This implements a very limited PEM header parser that does not support the
 473  * full grammar of rfc1421.  In particular, folded headers are not supported,
 474  * nor is additional whitespace.
 475  *
 476  * A robust implementation would make use of a library that turns the headers
 477  * into a BIO from which one folded line is read at a time, and is then split
 478  * into a header label and content.  We would then parse the content of the
 479  * headers we care about.  This is overkill for just this limited use-case, but
 480  * presumably we also parse rfc822-style headers for S/MIME, so a common
 481  * abstraction might well be more generally useful.
 482  */
 483 int PEM_get_EVP_CIPHER_INFO(char *header, EVP_CIPHER_INFO *cipher)
 484 {
 485     static const char ProcType[] = "Proc-Type:";
 486     static const char ENCRYPTED[] = "ENCRYPTED";
 487     static const char DEKInfo[] = "DEK-Info:";
 488     const EVP_CIPHER *enc = NULL;
 489     int ivlen;
 490     char *dekinfostart, c;
 491
 492     cipher->cipher = NULL;
 493     if ((header == NULL) || (*header == '\0') || (*header == '\n'))
 494         return 1;
 495
 496     if (strncmp(header, ProcType, sizeof(ProcType)-1) != 0) {
 497         PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_NOT_PROC_TYPE);
 498         return 0;
 499     }
 500     header += sizeof(ProcType)-1;
 501     header += strspn(header, " \t");
 502
 503     if (*header++ != '4' || *header++ != ',')
 504         return 0;
 505     header += strspn(header, " \t");
 506
 507     /* We expect "ENCRYPTED" followed by optional white-space + line break */
 508     if (strncmp(header, ENCRYPTED, sizeof(ENCRYPTED)-1) != 0 ||
 509         strspn(header+sizeof(ENCRYPTED)-1, " \t\r\n") == 0) {
 510         PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_NOT_ENCRYPTED);
 511         return 0;
 512     }
 513     header += sizeof(ENCRYPTED)-1;
 514     header += strspn(header, " \t\r");
 515     if (*header++ != '\n') {
 516         PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_SHORT_HEADER);
 517         return 0;
 518     }
 519
 520     /*-
 521      * https://tools.ietf.org/html/rfc1421#section-4.6.1.3
 522      * We expect "DEK-Info: algo[,hex-parameters]"
 523      */
 524     if (strncmp(header, DEKInfo, sizeof(DEKInfo)-1) != 0) {
 525         PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_NOT_DEK_INFO);
 526         return 0;
 527     }
 528     header += sizeof(DEKInfo)-1;
 529     header += strspn(header, " \t");
 530
 531     /*
 532      * DEK-INFO is a comma-separated combination of algorithm name and optional
 533      * parameters.
 534      */
 535     dekinfostart = header;
 536     header += strcspn(header, " \t,");
 537     c = *header;
 538     *header = '\0';
 539     cipher->cipher = enc = EVP_get_cipherbyname(dekinfostart);
 540     *header = c;
 541     header += strspn(header, " \t");
 542
 543     if (enc == NULL) {
 544         PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_UNSUPPORTED_ENCRYPTION);
 545         return 0;
 546     }
 547     ivlen = EVP_CIPHER_iv_length(enc);
 548     if (ivlen > 0 && *header++ != ',') {
 549         PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_MISSING_DEK_IV);
 550         return 0;
 551     } else if (ivlen == 0 && *header == ',') {
 552         PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_UNEXPECTED_DEK_IV);
 553         return 0;
 554     }
 555
 556     if (!load_iv(&header, cipher->iv, EVP_CIPHER_iv_length(enc)))
 557         return 0;
 558
 559     return 1;
 560 }
 561
 562 static int load_iv(char **fromp, unsigned char *to, int num)
 563 {
 564     int v, i;
 565     char *from;
 566
 567     from = *fromp;
 568     for (i = 0; i < num; i++)
 569         to[i] = 0;
 570     num *= 2;
 571     for (i = 0; i < num; i++) {
 572         v = OPENSSL_hexchar2int(*from);
 573         if (v < 0) {
 574             PEMerr(PEM_F_LOAD_IV, PEM_R_BAD_IV_CHARS);
 575             return (0);
 576         }
 577         from++;
 578         to[i / 2] |= v << (long)((!(i & 1)) * 4);
 579     }
 580
 581     *fromp = from;
 582     return (1);
 583 }
 584
 585 #ifndef OPENSSL_NO_STDIO
 586 int PEM_write(FILE *fp, const char *name, const char *header,
 587               const unsigned char *data, long len)
 588 {
 589     BIO *b;
 590     int ret;
 591
 592     if ((b = BIO_new(BIO_s_file())) == NULL) {
 593         PEMerr(PEM_F_PEM_WRITE, ERR_R_BUF_LIB);
 594         return (0);
 595     }
 596     BIO_set_fp(b, fp, BIO_NOCLOSE);
 597     ret = PEM_write_bio(b, name, header, data, len);
 598     BIO_free(b);
 599     return (ret);
 600 }
 601 #endif
 602
 603 int PEM_write_bio(BIO *bp, const char *name, const char *header,
 604                   const unsigned char *data, long len)
 605 {
 606     int nlen, n, i, j, outl;
 607     unsigned char *buf = NULL;
 608     EVP_ENCODE_CTX *ctx = EVP_ENCODE_CTX_new();
 609     int reason = ERR_R_BUF_LIB;
 610
 611     if (ctx == NULL) {
 612         reason = ERR_R_MALLOC_FAILURE;
 613         goto err;
 614     }
 615
 616     EVP_EncodeInit(ctx);
 617     nlen = strlen(name);
 618
 619     if ((BIO_write(bp, "-----BEGIN ", 11) != 11) ||
 620         (BIO_write(bp, name, nlen) != nlen) ||
 621         (BIO_write(bp, "-----\n", 6) != 6))
 622         goto err;
 623
 624     i = strlen(header);
 625     if (i > 0) {
 626         if ((BIO_write(bp, header, i) != i) || (BIO_write(bp, "\n", 1) != 1))
 627             goto err;
 628     }
 629
 630     buf = OPENSSL_malloc(PEM_BUFSIZE * 8);
 631     if (buf == NULL) {
 632         reason = ERR_R_MALLOC_FAILURE;
 633         goto err;
 634     }
 635
 636     i = j = 0;
 637     while (len > 0) {
 638         n = (int)((len > (PEM_BUFSIZE * 5)) ? (PEM_BUFSIZE * 5) : len);
 639         if (!EVP_EncodeUpdate(ctx, buf, &outl, &(data[j]), n))
 640             goto err;
 641         if ((outl) && (BIO_write(bp, (char *)buf, outl) != outl))
 642             goto err;
 643         i += outl;
 644         len -= n;
 645         j += n;
 646     }
 647     EVP_EncodeFinal(ctx, buf, &outl);
 648     if ((outl > 0) && (BIO_write(bp, (char *)buf, outl) != outl))
 649         goto err;
 650     if ((BIO_write(bp, "-----END ", 9) != 9) ||
 651         (BIO_write(bp, name, nlen) != nlen) ||
 652         (BIO_write(bp, "-----\n", 6) != 6))
 653         goto err;
 654     OPENSSL_clear_free(buf, PEM_BUFSIZE * 8);
 655     EVP_ENCODE_CTX_free(ctx);
 656     return (i + outl);
 657  err:
 658     OPENSSL_clear_free(buf, PEM_BUFSIZE * 8);
 659     EVP_ENCODE_CTX_free(ctx);
 660     PEMerr(PEM_F_PEM_WRITE_BIO, reason);
 661     return (0);
 662 }
 663
 664 #ifndef OPENSSL_NO_STDIO
 665 int PEM_read(FILE *fp, char **name, char **header, unsigned char **data,
 666              long *len)
 667 {
 668     BIO *b;
 669     int ret;
 670
 671     if ((b = BIO_new(BIO_s_file())) == NULL) {
 672         PEMerr(PEM_F_PEM_READ, ERR_R_BUF_LIB);
 673         return (0);
 674     }
 675     BIO_set_fp(b, fp, BIO_NOCLOSE);
 676     ret = PEM_read_bio(b, name, header, data, len);
 677     BIO_free(b);
 678     return (ret);
 679 }
 680 #endif
 681
 682 /* Some helpers for PEM_read_bio_ex(). */
 683
 684 #define isb64(c) (isalnum(c) || (c) == '+' || (c) == '/' || (c) == '=')
 685
 686 static int sanitize_line(char *linebuf, int len, unsigned int flags)
 687 {
 688     int i;
 689
 690     if (flags & PEM_FLAG_EAY_COMPATIBLE) {
 691         /* Strip trailing whitespace */
 692         while ((len >= 0) && (linebuf[len] <= ' '))
 693             len--;
 694         /* Go back to whitespace before applying uniform line ending. */
 695         len++;
 696     } else if (flags & PEM_FLAG_ONLY_B64) {
 697         for (i = 0; i < len; ++i) {
 698             if (!isb64(linebuf[i]) || linebuf[i] == '\n' || linebuf[i] == '\r')
 699                 break;
 700         }
 701         len = i;
 702     } else {
 703         /* EVP_DecodeBlock strips leading and trailing whitespace, so just strip
 704          * control characters in-place and let everything through. */
 705         for (i = 0; i < len; ++i) {
 706             if (linebuf[i] == '\n' || linebuf[i] == '\r')
 707                 break;
 708             if (iscntrl(linebuf[i]))
 709                 linebuf[i] = ' ';
 710         }
 711         len = i;
 712     }
 713     /* The caller allocated LINESIZE+1, so this is safe. */
 714     linebuf[len++] = '\n';
 715     linebuf[len] = '\0';
 716     return len;
 717 }
 718
 719 #define LINESIZE 255
 720 /* Note trailing spaces for begin and end. */
 721 static const char beginstr[] = "-----BEGIN ";
 722 static const char endstr[] = "-----END ";
 723 static const char tailstr[] = "-----\n";
 724 #define BEGINLEN (sizeof(beginstr) - 1)
 725 #define ENDLEN (sizeof(endstr) - 1)
 726 #define TAILLEN (sizeof(tailstr) - 1)
 727 static int get_name(BIO *bp, char **name, unsigned int flags)
 728 {
 729     char *linebuf;
 730     int ret = 0;
 731     size_t len;
 732
 733     /*
 734      * Need to hold trailing NUL (accounted for by BIO_gets() and the newline
 735      * that will be added by sanitize_line() (the extra '1').
 736      */
 737     linebuf = pem_malloc(LINESIZE + 1, flags);
 738     if (linebuf == NULL) {
 739         PEMerr(PEM_F_GET_NAME, ERR_R_MALLOC_FAILURE);
 740         return 0;
 741     }
 742
 743     do {
 744         len = BIO_gets(bp, linebuf, LINESIZE);
 745
 746         if (len <= 0) {
 747             PEMerr(PEM_F_GET_NAME, PEM_R_NO_START_LINE);
 748             goto err;
 749         }
 750
 751         /* Strip trailing garbage and standardize ending. */
 752         len = sanitize_line(linebuf, len, flags & ~PEM_FLAG_ONLY_B64);
 753
 754         /* Allow leading empty or non-matching lines. */
 755     } while (strncmp(linebuf, beginstr, BEGINLEN) != 0
 756              || len < TAILLEN
 757              || strncmp(linebuf + len - TAILLEN, tailstr, TAILLEN) != 0);
 758     linebuf[len - TAILLEN] = '\0';
 759     len = len - BEGINLEN - TAILLEN + 1;
 760     *name = pem_malloc(len, flags);
 761     if (*name == NULL) {
 762         PEMerr(PEM_F_GET_NAME, ERR_R_MALLOC_FAILURE);
 763         goto err;
 764     }
 765     memcpy(*name, linebuf + BEGINLEN, len);
 766     ret = 1;
 767
 768 err:
 769     pem_free(linebuf, flags);
 770     return ret;
 771 }
 772
 773 /* Keep track of how much of a header we've seen. */
 774 enum header_status {
 775     MAYBE_HEADER,
 776     IN_HEADER,
 777     POST_HEADER
 778 };
 779
 780 /**
 781  * Extract the optional PEM header, with details on the type of content and
 782  * any encryption used on the contents, and the bulk of the data from the bio.
 783  * The end of the header is marked by a blank line; if the end-of-input marker
 784  * is reached prior to a blank line, there is no header.
 785  *
 786  * The header and data arguments are BIO** since we may have to swap them
 787  * if there is no header, for efficiency.
 788  *
 789  * We need the name of the PEM-encoded type to verify the end string.
 790  */
 791 static int get_header_and_data(BIO *bp, BIO **header, BIO **data, char *name,
 792                                unsigned int flags)
 793 {
 794     BIO *tmp = *header;
 795     char *linebuf, *p;
 796     int len, line, ret = 0, end = 0;
 797     /* 0 if not seen (yet), 1 if reading header, 2 if finished header */
 798     enum header_status got_header = MAYBE_HEADER;
 799     unsigned int flags_mask;
 800     size_t namelen;
 801
 802     /* Need to hold trailing NUL (accounted for by BIO_gets() and the newline
 803      * that will be added by sanitize_line() (the extra '1'). */
 804     linebuf = pem_malloc(LINESIZE + 1, flags);
 805     if (linebuf == NULL) {
 806         PEMerr(PEM_F_GET_HEADER_AND_DATA, ERR_R_MALLOC_FAILURE);
 807         return 0;
 808     }
 809
 810     for (line = 0; ; line++) {
 811         flags_mask = ~0u;
 812         len = BIO_gets(bp, linebuf, LINESIZE);
 813         if (len <= 0) {
 814             PEMerr(PEM_F_GET_HEADER_AND_DATA, PEM_R_SHORT_HEADER);
 815             goto err;
 816         }
 817
 818         if (got_header == MAYBE_HEADER) {
 819             if (memchr(linebuf, ':', len) != NULL)
 820                 got_header = IN_HEADER;
 821         }
 822         if (!strncmp(linebuf, endstr, ENDLEN) || got_header == IN_HEADER)
 823             flags_mask &= ~PEM_FLAG_ONLY_B64;
 824         len = sanitize_line(linebuf, len, flags & flags_mask);
 825
 826         /* Check for end of header. */
 827         if (linebuf[0] == '\n') {
 828             if (got_header == POST_HEADER) {
 829                 /* Another blank line is an error. */
 830                 PEMerr(PEM_F_GET_HEADER_AND_DATA, PEM_R_BAD_END_LINE);
 831                 goto err;
 832             }
 833             got_header = POST_HEADER;
 834             tmp = *data;
 835             continue;
 836         }
 837
 838         /* Check for end of stream (which means there is no header). */
 839         if (strncmp(linebuf, endstr, ENDLEN) == 0) {
 840             p = linebuf + ENDLEN;
 841             namelen = strlen(name);
 842             if (strncmp(p, name, namelen) != 0 ||
 843                 strncmp(p + namelen, tailstr, TAILLEN) != 0) {
 844                 PEMerr(PEM_F_GET_HEADER_AND_DATA, PEM_R_BAD_END_LINE);
 845                 goto err;
 846             }
 847             if (got_header == MAYBE_HEADER) {
 848                 *header = *data;
 849                 *data = tmp;
 850             }
 851             break;
 852         } else if (end) {
 853             /* Malformed input; short line not at end of data. */
 854             PEMerr(PEM_F_GET_HEADER_AND_DATA, PEM_R_BAD_END_LINE);
 855             goto err;
 856         }
 857         /*
 858          * Else, a line of text -- could be header or data; we don't
 859          * know yet.  Just pass it through.
 860          */
 861         BIO_puts(tmp, linebuf);
 862         /*
 863          * Only encrypted files need the line length check applied.
 864          */
 865         if (got_header == POST_HEADER) {
 866             /* 65 includes the trailing newline */
 867             if (len > 65)
 868                 goto err;
 869             if (len < 65)
 870                 end = 1;
 871         }
 872     }
 873
 874     ret = 1;
 875 err:
 876     pem_free(linebuf, flags);
 877     return ret;
 878 }
 879
 880 /**
 881  * Read in PEM-formatted data from the given BIO.
 882  *
 883  * By nature of the PEM format, all content must be printable ASCII (except
 884  * for line endings).  Other characters, or lines that are longer than 80
 885  * characters, are malformed input and will be rejected.
 886  */
 887 int PEM_read_bio_ex(BIO *bp, char **name_out, char **header,
 888                     unsigned char **data, long *len_out, unsigned int flags)
 889 {
 890     EVP_ENCODE_CTX *ctx = EVP_ENCODE_CTX_new();
 891     const BIO_METHOD *bmeth;
 892     BIO *headerB = NULL, *dataB = NULL;
 893     char *name = NULL;
 894     int len, taillen, headerlen, ret = 0;
 895     BUF_MEM * buf_mem;
 896
 897     if (ctx == NULL) {
 898         PEMerr(PEM_F_PEM_READ_BIO_EX, ERR_R_MALLOC_FAILURE);
 899         return 0;
 900     }
 901
 902     *len_out = 0;
 903     *name_out = *header = NULL;
 904     *data = NULL;
 905     if ((flags & PEM_FLAG_EAY_COMPATIBLE) && (flags & PEM_FLAG_ONLY_B64)) {
 906         /* These two are mutually incompatible; bail out. */
 907         PEMerr(PEM_F_PEM_READ_BIO_EX, ERR_R_PASSED_INVALID_ARGUMENT);
 908         goto end;
 909     }
 910     bmeth = (flags & PEM_FLAG_SECURE) ? BIO_s_secmem() : BIO_s_mem();
 911
 912     headerB = BIO_new(bmeth);
 913     dataB = BIO_new(bmeth);
 914     if (headerB == NULL || dataB == NULL) {
 915         PEMerr(PEM_F_PEM_READ_BIO_EX, ERR_R_MALLOC_FAILURE);
 916         goto end;
 917     }
 918
 919     if (!get_name(bp, &name, flags))
 920         goto end;
 921     if (!get_header_and_data(bp, &headerB, &dataB, name, flags))
 922         goto end;
 923
 924     EVP_DecodeInit(ctx);
 925     BIO_get_mem_ptr(dataB, &buf_mem);
 926     len = buf_mem->length;
 927     if (EVP_DecodeUpdate(ctx, (unsigned char*)buf_mem->data, &len,
 928                          (unsigned char*)buf_mem->data, len) < 0
 929             || EVP_DecodeFinal(ctx, (unsigned char*)&(buf_mem->data[len]),
 930                                &taillen) < 0) {
 931         PEMerr(PEM_F_PEM_READ_BIO_EX, PEM_R_BAD_BASE64_DECODE);
 932         goto end;
 933     }
 934     len += taillen;
 935     buf_mem->length = len;
 936
 937     /* There was no data in the PEM file; avoid malloc(0). */
 938     if (len == 0)
 939         goto end;
 940     headerlen = BIO_get_mem_data(headerB, NULL);
 941     *header = pem_malloc(headerlen + 1, flags);
 942     *data = pem_malloc(len, flags);
 943     if (*header == NULL || *data == NULL) {
 944         pem_free(*header, flags);
 945         pem_free(*data, flags);
 946         goto end;
 947     }
 948     BIO_read(headerB, *header, headerlen);
 949     (*header)[headerlen] = '\0';
 950     BIO_read(dataB, *data, len);
 951     *len_out = len;
 952     *name_out = name;
 953     name = NULL;
 954     ret = 1;
 955
 956 end:
 957     EVP_ENCODE_CTX_free(ctx);
 958     pem_free(name, flags);
 959     BIO_free(headerB);
 960     BIO_free(dataB);
 961     return ret;
 962 }
 963
 964 int PEM_read_bio(BIO *bp, char **name, char **header, unsigned char **data,
 965                  long *len)
 966 {
 967     return PEM_read_bio_ex(bp, name, header, data, len, PEM_FLAG_EAY_COMPATIBLE);
 968 }
 969
 970 /*
 971  * Check pem string and return prefix length. If for example the pem_str ==
 972  * "RSA PRIVATE KEY" and suffix = "PRIVATE KEY" the return value is 3 for the
 973  * string "RSA".
 974  */
 975
 976 int pem_check_suffix(const char *pem_str, const char *suffix)
 977 {
 978     int pem_len = strlen(pem_str);
 979     int suffix_len = strlen(suffix);
 980     const char *p;
 981     if (suffix_len + 1 >= pem_len)
 982         return 0;
 983     p = pem_str + pem_len - suffix_len;
 984     if (strcmp(p, suffix))
 985         return 0;
 986     p--;
 987     if (*p != ' ')
 988         return 0;
 989     return p - pem_str;
 990 }