crypto/pem/pem_lib.c

   1 /*
   2  * Copyright 1995-2020 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 #include <stdio.h>
  11 #include "crypto/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 "crypto/asn1.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 rwflag, void *userdata)
  32 {
  33     int i, min_len;
  34     const char *prompt;
  35
  36     /* We assume that the user passes a default password as userdata */
  37     if (userdata) {
  38         i = strlen(userdata);
  39         i = (i > num) ? num : i;
  40         memcpy(buf, userdata, i);
  41         return i;
  42     }
  43
  44     prompt = EVP_get_pw_prompt();
  45     if (prompt == NULL)
  46         prompt = "Enter PEM pass phrase:";
  47
  48     /*
  49      * rwflag == 0 means decryption
  50      * rwflag == 1 means encryption
  51      *
  52      * We assume that for encryption, we want a minimum length, while for
  53      * decryption, we cannot know any minimum length, so we assume zero.
  54      */
  55     min_len = rwflag ? MIN_LENGTH : 0;
  56
  57     i = EVP_read_pw_string_min(buf, min_len, num, prompt, rwflag);
  58     if (i != 0) {
  59         PEMerr(PEM_F_PEM_DEF_CALLBACK, PEM_R_PROBLEMS_GETTING_PASSWORD);
  60         memset(buf, 0, (unsigned int)num);
  61         return -1;
  62     }
  63     return strlen(buf);
  64 }
  65
  66 void PEM_proc_type(char *buf, int type)
  67 {
  68     const char *str;
  69     char *p = buf + strlen(buf);
  70
  71     if (type == PEM_TYPE_ENCRYPTED)
  72         str = "ENCRYPTED";
  73     else if (type == PEM_TYPE_MIC_CLEAR)
  74         str = "MIC-CLEAR";
  75     else if (type == PEM_TYPE_MIC_ONLY)
  76         str = "MIC-ONLY";
  77     else
  78         str = "BAD-TYPE";
  79
  80     BIO_snprintf(p, PEM_BUFSIZE - (size_t)(p - buf), "Proc-Type: 4,%s\n", str);
  81 }
  82
  83 void PEM_dek_info(char *buf, const char *type, int len, const char *str)
  84 {
  85     long i;
  86     char *p = buf + strlen(buf);
  87     int j = PEM_BUFSIZE - (size_t)(p - buf), n;
  88
  89     n = BIO_snprintf(p, j, "DEK-Info: %s,", type);
  90     if (n > 0) {
  91         j -= n;
  92         p += n;
  93         for (i = 0; i < len; i++) {
  94             n = BIO_snprintf(p, j, "%02X", 0xff & str[i]);
  95             if (n <= 0)
  96                 return;
  97             j -= n;
  98             p += n;
  99         }
 100         if (j > 1)
 101             strcpy(p, "\n");
 102     }
 103 }
 104
 105 #ifndef OPENSSL_NO_STDIO
 106 void *PEM_ASN1_read(d2i_of_void *d2i, const char *name, FILE *fp, void **x,
 107                     pem_password_cb *cb, void *u)
 108 {
 109     BIO *b;
 110     void *ret;
 111
 112     if ((b = BIO_new(BIO_s_file())) == NULL) {
 113         PEMerr(PEM_F_PEM_ASN1_READ, ERR_R_BUF_LIB);
 114         return 0;
 115     }
 116     BIO_set_fp(b, fp, BIO_NOCLOSE);
 117     ret = PEM_ASN1_read_bio(d2i, name, b, x, cb, u);
 118     BIO_free(b);
 119     return ret;
 120 }
 121 #endif
 122
 123 static int check_pem(const char *nm, const char *name)
 124 {
 125     /* Normal matching nm and name */
 126     if (strcmp(nm, name) == 0)
 127         return 1;
 128
 129     /* Make PEM_STRING_EVP_PKEY match any private key */
 130
 131     if (strcmp(name, PEM_STRING_EVP_PKEY) == 0) {
 132         int slen;
 133         const EVP_PKEY_ASN1_METHOD *ameth;
 134         if (strcmp(nm, PEM_STRING_PKCS8) == 0)
 135             return 1;
 136         if (strcmp(nm, PEM_STRING_PKCS8INF) == 0)
 137             return 1;
 138         slen = pem_check_suffix(nm, "PRIVATE KEY");
 139         if (slen > 0) {
 140             /*
 141              * NB: ENGINE implementations won't contain a deprecated old
 142              * private key decode function so don't look for them.
 143              */
 144             ameth = EVP_PKEY_asn1_find_str(NULL, nm, slen);
 145             if (ameth && ameth->old_priv_decode)
 146                 return 1;
 147         }
 148         return 0;
 149     }
 150
 151     if (strcmp(name, PEM_STRING_PARAMETERS) == 0) {
 152         int slen;
 153         const EVP_PKEY_ASN1_METHOD *ameth;
 154         slen = pem_check_suffix(nm, "PARAMETERS");
 155         if (slen > 0) {
 156             ENGINE *e;
 157             ameth = EVP_PKEY_asn1_find_str(&e, nm, slen);
 158             if (ameth) {
 159                 int r;
 160                 if (ameth->param_decode)
 161                     r = 1;
 162                 else
 163                     r = 0;
 164 #ifndef OPENSSL_NO_ENGINE
 165                 ENGINE_finish(e);
 166 #endif
 167                 return r;
 168             }
 169         }
 170         return 0;
 171     }
 172     /* If reading DH parameters handle X9.42 DH format too */
 173     if (strcmp(nm, PEM_STRING_DHXPARAMS) == 0
 174         && strcmp(name, PEM_STRING_DHPARAMS) == 0)
 175         return 1;
 176
 177     /* Permit older strings */
 178
 179     if (strcmp(nm, PEM_STRING_X509_OLD) == 0
 180         && strcmp(name, PEM_STRING_X509) == 0)
 181         return 1;
 182
 183     if (strcmp(nm, PEM_STRING_X509_REQ_OLD) == 0
 184         && strcmp(name, PEM_STRING_X509_REQ) == 0)
 185         return 1;
 186
 187     /* Allow normal certs to be read as trusted certs */
 188     if (strcmp(nm, PEM_STRING_X509) == 0
 189         && strcmp(name, PEM_STRING_X509_TRUSTED) == 0)
 190         return 1;
 191
 192     if (strcmp(nm, PEM_STRING_X509_OLD) == 0
 193         && strcmp(name, PEM_STRING_X509_TRUSTED) == 0)
 194         return 1;
 195
 196     /* Some CAs use PKCS#7 with CERTIFICATE headers */
 197     if (strcmp(nm, PEM_STRING_X509) == 0
 198         && strcmp(name, PEM_STRING_PKCS7) == 0)
 199         return 1;
 200
 201     if (strcmp(nm, PEM_STRING_PKCS7_SIGNED) == 0
 202         && strcmp(name, PEM_STRING_PKCS7) == 0)
 203         return 1;
 204
 205 #ifndef OPENSSL_NO_CMS
 206     if (strcmp(nm, PEM_STRING_X509) == 0
 207         && strcmp(name, PEM_STRING_CMS) == 0)
 208         return 1;
 209     /* Allow CMS to be read from PKCS#7 headers */
 210     if (strcmp(nm, PEM_STRING_PKCS7) == 0
 211         && strcmp(name, PEM_STRING_CMS) == 0)
 212         return 1;
 213 #endif
 214
 215     return 0;
 216 }
 217
 218 static void pem_free(void *p, unsigned int flags, size_t num)
 219 {
 220     if (flags & PEM_FLAG_SECURE)
 221         OPENSSL_secure_clear_free(p, num);
 222     else
 223         OPENSSL_free(p);
 224 }
 225
 226 static void *pem_malloc(int num, unsigned int flags)
 227 {
 228     return (flags & PEM_FLAG_SECURE) ? OPENSSL_secure_malloc(num)
 229                                      : OPENSSL_malloc(num);
 230 }
 231
 232 static int pem_bytes_read_bio_flags(unsigned char **pdata, long *plen,
 233                                     char **pnm, const char *name, BIO *bp,
 234                                     pem_password_cb *cb, void *u,
 235                                     unsigned int flags)
 236 {
 237     EVP_CIPHER_INFO cipher;
 238     char *nm = NULL, *header = NULL;
 239     unsigned char *data = NULL;
 240     long len = 0;
 241     int ret = 0;
 242
 243     do {
 244         pem_free(nm, flags, 0);
 245         pem_free(header, flags, 0);
 246         pem_free(data, flags, len);
 247         if (!PEM_read_bio_ex(bp, &nm, &header, &data, &len, flags)) {
 248             if (ERR_GET_REASON(ERR_peek_error()) == PEM_R_NO_START_LINE)
 249                 ERR_add_error_data(2, "Expecting: ", name);
 250             return 0;
 251         }
 252     } while (!check_pem(nm, name));
 253     if (!PEM_get_EVP_CIPHER_INFO(header, &cipher))
 254         goto err;
 255     if (!PEM_do_header(&cipher, data, &len, cb, u))
 256         goto err;
 257
 258     *pdata = data;
 259     *plen = len;
 260
 261     if (pnm != NULL)
 262         *pnm = nm;
 263
 264     ret = 1;
 265
 266  err:
 267     if (!ret || pnm == NULL)
 268         pem_free(nm, flags, 0);
 269     pem_free(header, flags, 0);
 270     if (!ret)
 271         pem_free(data, flags, len);
 272     return ret;
 273 }
 274
 275 int PEM_bytes_read_bio(unsigned char **pdata, long *plen, char **pnm,
 276                        const char *name, BIO *bp, pem_password_cb *cb,
 277                        void *u) {
 278     return pem_bytes_read_bio_flags(pdata, plen, pnm, name, bp, cb, u,
 279                                     PEM_FLAG_EAY_COMPATIBLE);
 280 }
 281
 282 int PEM_bytes_read_bio_secmem(unsigned char **pdata, long *plen, char **pnm,
 283                               const char *name, BIO *bp, pem_password_cb *cb,
 284                               void *u) {
 285     return pem_bytes_read_bio_flags(pdata, plen, pnm, name, bp, cb, u,
 286                                     PEM_FLAG_SECURE | PEM_FLAG_EAY_COMPATIBLE);
 287 }
 288
 289 #ifndef OPENSSL_NO_STDIO
 290 int PEM_ASN1_write(i2d_of_void *i2d, const char *name, FILE *fp,
 291                    const void *x, const EVP_CIPHER *enc,
 292                    const unsigned char *kstr, int klen,
 293                    pem_password_cb *callback, void *u)
 294 {
 295     BIO *b;
 296     int ret;
 297
 298     if ((b = BIO_new(BIO_s_file())) == NULL) {
 299         PEMerr(PEM_F_PEM_ASN1_WRITE, ERR_R_BUF_LIB);
 300         return 0;
 301     }
 302     BIO_set_fp(b, fp, BIO_NOCLOSE);
 303     ret = PEM_ASN1_write_bio(i2d, name, b, x, enc, kstr, klen, callback, u);
 304     BIO_free(b);
 305     return ret;
 306 }
 307 #endif
 308
 309 int PEM_ASN1_write_bio(i2d_of_void *i2d, const char *name, BIO *bp,
 310                        const void *x, const EVP_CIPHER *enc,
 311                        const unsigned char *kstr, int klen,
 312                        pem_password_cb *callback, void *u)
 313 {
 314     EVP_CIPHER_CTX *ctx = NULL;
 315     int dsize = 0, i = 0, j = 0, ret = 0;
 316     unsigned char *p, *data = NULL;
 317     const char *objstr = NULL;
 318     char buf[PEM_BUFSIZE];
 319     unsigned char key[EVP_MAX_KEY_LENGTH];
 320     unsigned char iv[EVP_MAX_IV_LENGTH];
 321
 322     if (enc != NULL) {
 323         objstr = OBJ_nid2sn(EVP_CIPHER_nid(enc));
 324         if (objstr == NULL || EVP_CIPHER_iv_length(enc) == 0
 325                 || EVP_CIPHER_iv_length(enc) > (int)sizeof(iv)
 326                    /*
 327                     * Check "Proc-Type: 4,Encrypted\nDEK-Info: objstr,hex-iv\n"
 328                     * fits into buf
 329                     */
 330                 || (strlen(objstr) + 23 + 2 * EVP_CIPHER_iv_length(enc) + 13)
 331                    > sizeof(buf)) {
 332             PEMerr(PEM_F_PEM_ASN1_WRITE_BIO, PEM_R_UNSUPPORTED_CIPHER);
 333             goto err;
 334         }
 335     }
 336
 337     if ((dsize = i2d(x, NULL)) < 0) {
 338         PEMerr(PEM_F_PEM_ASN1_WRITE_BIO, ERR_R_ASN1_LIB);
 339         dsize = 0;
 340         goto err;
 341     }
 342     /* dsize + 8 bytes are needed */
 343     /* actually it needs the cipher block size extra... */
 344     data = OPENSSL_malloc((unsigned int)dsize + 20);
 345     if (data == NULL) {
 346         PEMerr(PEM_F_PEM_ASN1_WRITE_BIO, ERR_R_MALLOC_FAILURE);
 347         goto err;
 348     }
 349     p = data;
 350     i = i2d(x, &p);
 351
 352     if (enc != NULL) {
 353         if (kstr == NULL) {
 354             if (callback == NULL)
 355                 klen = PEM_def_callback(buf, PEM_BUFSIZE, 1, u);
 356             else
 357                 klen = (*callback) (buf, PEM_BUFSIZE, 1, u);
 358             if (klen <= 0) {
 359                 PEMerr(PEM_F_PEM_ASN1_WRITE_BIO, PEM_R_READ_KEY);
 360                 goto err;
 361             }
 362 #ifdef CHARSET_EBCDIC
 363             /* Convert the pass phrase from EBCDIC */
 364             ebcdic2ascii(buf, buf, klen);
 365 #endif
 366             kstr = (unsigned char *)buf;
 367         }
 368         if (RAND_bytes(iv, EVP_CIPHER_iv_length(enc)) <= 0) /* Generate a salt */
 369             goto err;
 370         /*
 371          * The 'iv' is used as the iv and as a salt.  It is NOT taken from
 372          * the BytesToKey function
 373          */
 374         if (!EVP_BytesToKey(enc, EVP_md5(), iv, kstr, klen, 1, key, NULL))
 375             goto err;
 376
 377         if (kstr == (unsigned char *)buf)
 378             OPENSSL_cleanse(buf, PEM_BUFSIZE);
 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     memset(cipher->iv, 0, sizeof(cipher->iv));
 494     if ((header == NULL) || (*header == '\0') || (*header == '\n'))
 495         return 1;
 496
 497     if (strncmp(header, ProcType, sizeof(ProcType)-1) != 0) {
 498         PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_NOT_PROC_TYPE);
 499         return 0;
 500     }
 501     header += sizeof(ProcType)-1;
 502     header += strspn(header, " \t");
 503
 504     if (*header++ != '4' || *header++ != ',')
 505         return 0;
 506     header += strspn(header, " \t");
 507
 508     /* We expect "ENCRYPTED" followed by optional white-space + line break */
 509     if (strncmp(header, ENCRYPTED, sizeof(ENCRYPTED)-1) != 0 ||
 510         strspn(header+sizeof(ENCRYPTED)-1, " \t\r\n") == 0) {
 511         PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_NOT_ENCRYPTED);
 512         return 0;
 513     }
 514     header += sizeof(ENCRYPTED)-1;
 515     header += strspn(header, " \t\r");
 516     if (*header++ != '\n') {
 517         PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_SHORT_HEADER);
 518         return 0;
 519     }
 520
 521     /*-
 522      * https://tools.ietf.org/html/rfc1421#section-4.6.1.3
 523      * We expect "DEK-Info: algo[,hex-parameters]"
 524      */
 525     if (strncmp(header, DEKInfo, sizeof(DEKInfo)-1) != 0) {
 526         PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_NOT_DEK_INFO);
 527         return 0;
 528     }
 529     header += sizeof(DEKInfo)-1;
 530     header += strspn(header, " \t");
 531
 532     /*
 533      * DEK-INFO is a comma-separated combination of algorithm name and optional
 534      * parameters.
 535      */
 536     dekinfostart = header;
 537     header += strcspn(header, " \t,");
 538     c = *header;
 539     *header = '\0';
 540     cipher->cipher = enc = EVP_get_cipherbyname(dekinfostart);
 541     *header = c;
 542     header += strspn(header, " \t");
 543
 544     if (enc == NULL) {
 545         PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_UNSUPPORTED_ENCRYPTION);
 546         return 0;
 547     }
 548     ivlen = EVP_CIPHER_iv_length(enc);
 549     if (ivlen > 0 && *header++ != ',') {
 550         PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_MISSING_DEK_IV);
 551         return 0;
 552     } else if (ivlen == 0 && *header == ',') {
 553         PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_UNEXPECTED_DEK_IV);
 554         return 0;
 555     }
 556
 557     if (!load_iv(&header, cipher->iv, EVP_CIPHER_iv_length(enc)))
 558         return 0;
 559
 560     return 1;
 561 }
 562
 563 static int load_iv(char **fromp, unsigned char *to, int num)
 564 {
 565     int v, i;
 566     char *from;
 567
 568     from = *fromp;
 569     for (i = 0; i < num; i++)
 570         to[i] = 0;
 571     num *= 2;
 572     for (i = 0; i < num; i++) {
 573         v = OPENSSL_hexchar2int(*from);
 574         if (v < 0) {
 575             PEMerr(PEM_F_LOAD_IV, PEM_R_BAD_IV_CHARS);
 576             return 0;
 577         }
 578         from++;
 579         to[i / 2] |= v << (long)((!(i & 1)) * 4);
 580     }
 581
 582     *fromp = from;
 583     return 1;
 584 }
 585
 586 #ifndef OPENSSL_NO_STDIO
 587 int PEM_write(FILE *fp, const char *name, const char *header,
 588               const unsigned char *data, long len)
 589 {
 590     BIO *b;
 591     int ret;
 592
 593     if ((b = BIO_new(BIO_s_file())) == NULL) {
 594         PEMerr(PEM_F_PEM_WRITE, ERR_R_BUF_LIB);
 595         return 0;
 596     }
 597     BIO_set_fp(b, fp, BIO_NOCLOSE);
 598     ret = PEM_write_bio(b, name, header, data, len);
 599     BIO_free(b);
 600     return ret;
 601 }
 602 #endif
 603
 604 int PEM_write_bio(BIO *bp, const char *name, const char *header,
 605                   const unsigned char *data, long len)
 606 {
 607     int nlen, n, i, j, outl;
 608     unsigned char *buf = NULL;
 609     EVP_ENCODE_CTX *ctx = EVP_ENCODE_CTX_new();
 610     int reason = ERR_R_BUF_LIB;
 611     int retval = 0;
 612
 613     if (ctx == NULL) {
 614         reason = ERR_R_MALLOC_FAILURE;
 615         goto err;
 616     }
 617
 618     EVP_EncodeInit(ctx);
 619     nlen = strlen(name);
 620
 621     if ((BIO_write(bp, "-----BEGIN ", 11) != 11) ||
 622         (BIO_write(bp, name, nlen) != nlen) ||
 623         (BIO_write(bp, "-----\n", 6) != 6))
 624         goto err;
 625
 626     i = strlen(header);
 627     if (i > 0) {
 628         if ((BIO_write(bp, header, i) != i) || (BIO_write(bp, "\n", 1) != 1))
 629             goto err;
 630     }
 631
 632     buf = OPENSSL_malloc(PEM_BUFSIZE * 8);
 633     if (buf == NULL) {
 634         reason = ERR_R_MALLOC_FAILURE;
 635         goto err;
 636     }
 637
 638     i = j = 0;
 639     while (len > 0) {
 640         n = (int)((len > (PEM_BUFSIZE * 5)) ? (PEM_BUFSIZE * 5) : len);
 641         if (!EVP_EncodeUpdate(ctx, buf, &outl, &(data[j]), n))
 642             goto err;
 643         if ((outl) && (BIO_write(bp, (char *)buf, outl) != outl))
 644             goto err;
 645         i += outl;
 646         len -= n;
 647         j += n;
 648     }
 649     EVP_EncodeFinal(ctx, buf, &outl);
 650     if ((outl > 0) && (BIO_write(bp, (char *)buf, outl) != outl))
 651         goto err;
 652     if ((BIO_write(bp, "-----END ", 9) != 9) ||
 653         (BIO_write(bp, name, nlen) != nlen) ||
 654         (BIO_write(bp, "-----\n", 6) != 6))
 655         goto err;
 656     retval = i + outl;
 657
 658  err:
 659     if (retval == 0)
 660         PEMerr(PEM_F_PEM_WRITE_BIO, reason);
 661     EVP_ENCODE_CTX_free(ctx);
 662     OPENSSL_clear_free(buf, PEM_BUFSIZE * 8);
 663     return retval;
 664 }
 665
 666 #ifndef OPENSSL_NO_STDIO
 667 int PEM_read(FILE *fp, char **name, char **header, unsigned char **data,
 668              long *len)
 669 {
 670     BIO *b;
 671     int ret;
 672
 673     if ((b = BIO_new(BIO_s_file())) == NULL) {
 674         PEMerr(PEM_F_PEM_READ, ERR_R_BUF_LIB);
 675         return 0;
 676     }
 677     BIO_set_fp(b, fp, BIO_NOCLOSE);
 678     ret = PEM_read_bio(b, name, header, data, len);
 679     BIO_free(b);
 680     return ret;
 681 }
 682 #endif
 683
 684 /* Some helpers for PEM_read_bio_ex(). */
 685 static int sanitize_line(char *linebuf, int len, unsigned int flags, int first_call)
 686 {
 687     int i;
 688     if (first_call) {
 689         /* Other BOMs imply unsupported multibyte encoding,
 690          * so don't strip them and let the error raise */
 691         const unsigned char utf8_bom[3] = {0xEF, 0xBB, 0xBF};
 692
 693         if (len > 3 && memcmp(linebuf, utf8_bom, 3) == 0) {
 694             memmove(linebuf, linebuf + 3, len - 3);
 695             linebuf[len - 3] = 0;
 696             len -= 3;
 697         }
 698     }
 699
 700     if (flags & PEM_FLAG_EAY_COMPATIBLE) {
 701         /* Strip trailing whitespace */
 702         while ((len >= 0) && (linebuf[len] <= ' '))
 703             len--;
 704         /* Go back to whitespace before applying uniform line ending. */
 705         len++;
 706     } else if (flags & PEM_FLAG_ONLY_B64) {
 707         for (i = 0; i < len; ++i) {
 708             if (!ossl_isbase64(linebuf[i]) || linebuf[i] == '\n'
 709                 || linebuf[i] == '\r')
 710                 break;
 711         }
 712         len = i;
 713     } else {
 714         /* EVP_DecodeBlock strips leading and trailing whitespace, so just strip
 715          * control characters in-place and let everything through. */
 716         for (i = 0; i < len; ++i) {
 717             if (linebuf[i] == '\n' || linebuf[i] == '\r')
 718                 break;
 719             if (ossl_iscntrl(linebuf[i]))
 720                 linebuf[i] = ' ';
 721         }
 722         len = i;
 723     }
 724     /* The caller allocated LINESIZE+1, so this is safe. */
 725     linebuf[len++] = '\n';
 726     linebuf[len] = '\0';
 727     return len;
 728 }
 729
 730 #define LINESIZE 255
 731 /* Note trailing spaces for begin and end. */
 732 static const char beginstr[] = "-----BEGIN ";
 733 static const char endstr[] = "-----END ";
 734 static const char tailstr[] = "-----\n";
 735 #define BEGINLEN ((int)(sizeof(beginstr) - 1))
 736 #define ENDLEN ((int)(sizeof(endstr) - 1))
 737 #define TAILLEN ((int)(sizeof(tailstr) - 1))
 738 static int get_name(BIO *bp, char **name, unsigned int flags)
 739 {
 740     char *linebuf;
 741     int ret = 0;
 742     int len;
 743     int first_call = 1;
 744
 745     /*
 746      * Need to hold trailing NUL (accounted for by BIO_gets() and the newline
 747      * that will be added by sanitize_line() (the extra '1').
 748      */
 749     linebuf = pem_malloc(LINESIZE + 1, flags);
 750     if (linebuf == NULL) {
 751         PEMerr(PEM_F_GET_NAME, ERR_R_MALLOC_FAILURE);
 752         return 0;
 753     }
 754
 755     do {
 756         len = BIO_gets(bp, linebuf, LINESIZE);
 757
 758         if (len <= 0) {
 759             PEMerr(PEM_F_GET_NAME, PEM_R_NO_START_LINE);
 760             goto err;
 761         }
 762
 763         /* Strip trailing garbage and standardize ending. */
 764         len = sanitize_line(linebuf, len, flags & ~PEM_FLAG_ONLY_B64, first_call);
 765         first_call = 0;
 766
 767         /* Allow leading empty or non-matching lines. */
 768     } while (strncmp(linebuf, beginstr, BEGINLEN) != 0
 769              || len < TAILLEN
 770              || strncmp(linebuf + len - TAILLEN, tailstr, TAILLEN) != 0);
 771     linebuf[len - TAILLEN] = '\0';
 772     len = len - BEGINLEN - TAILLEN + 1;
 773     *name = pem_malloc(len, flags);
 774     if (*name == NULL) {
 775         PEMerr(PEM_F_GET_NAME, ERR_R_MALLOC_FAILURE);
 776         goto err;
 777     }
 778     memcpy(*name, linebuf + BEGINLEN, len);
 779     ret = 1;
 780
 781 err:
 782     pem_free(linebuf, flags, LINESIZE + 1);
 783     return ret;
 784 }
 785
 786 /* Keep track of how much of a header we've seen. */
 787 enum header_status {
 788     MAYBE_HEADER,
 789     IN_HEADER,
 790     POST_HEADER
 791 };
 792
 793 /**
 794  * Extract the optional PEM header, with details on the type of content and
 795  * any encryption used on the contents, and the bulk of the data from the bio.
 796  * The end of the header is marked by a blank line; if the end-of-input marker
 797  * is reached prior to a blank line, there is no header.
 798  *
 799  * The header and data arguments are BIO** since we may have to swap them
 800  * if there is no header, for efficiency.
 801  *
 802  * We need the name of the PEM-encoded type to verify the end string.
 803  */
 804 static int get_header_and_data(BIO *bp, BIO **header, BIO **data, char *name,
 805                                unsigned int flags)
 806 {
 807     BIO *tmp = *header;
 808     char *linebuf, *p;
 809     int len, line, ret = 0, end = 0, prev_partial_line_read = 0, partial_line_read = 0;
 810     /* 0 if not seen (yet), 1 if reading header, 2 if finished header */
 811     enum header_status got_header = MAYBE_HEADER;
 812     unsigned int flags_mask;
 813     size_t namelen;
 814
 815     /* Need to hold trailing NUL (accounted for by BIO_gets() and the newline
 816      * that will be added by sanitize_line() (the extra '1'). */
 817     linebuf = pem_malloc(LINESIZE + 1, flags);
 818     if (linebuf == NULL) {
 819         PEMerr(PEM_F_GET_HEADER_AND_DATA, ERR_R_MALLOC_FAILURE);
 820         return 0;
 821     }
 822
 823     for (line = 0; ; line++) {
 824         flags_mask = ~0u;
 825         len = BIO_gets(bp, linebuf, LINESIZE);
 826         if (len <= 0) {
 827             PEMerr(PEM_F_GET_HEADER_AND_DATA, PEM_R_BAD_END_LINE);
 828             goto err;
 829         }
 830
 831         /*
 832          * Check if line has been read completely or if only part of the line
 833          * has been read. Keep the previous value to ignore newlines that
 834          * appear due to reading a line up until the char before the newline.
 835          */
 836         prev_partial_line_read = partial_line_read;
 837         partial_line_read = len == LINESIZE-1 && linebuf[LINESIZE-2] != '\n';
 838
 839         if (got_header == MAYBE_HEADER) {
 840             if (memchr(linebuf, ':', len) != NULL)
 841                 got_header = IN_HEADER;
 842         }
 843         if (!strncmp(linebuf, endstr, ENDLEN) || got_header == IN_HEADER)
 844             flags_mask &= ~PEM_FLAG_ONLY_B64;
 845         len = sanitize_line(linebuf, len, flags & flags_mask, 0);
 846
 847         /* Check for end of header. */
 848         if (linebuf[0] == '\n') {
 849             /*
 850              * If previous line has been read only partially this newline is a
 851              * regular newline at the end of a line and not an empty line.
 852              */
 853             if (!prev_partial_line_read) {
 854                 if (got_header == POST_HEADER) {
 855                     /* Another blank line is an error. */
 856                     PEMerr(PEM_F_GET_HEADER_AND_DATA, PEM_R_BAD_END_LINE);
 857                     goto err;
 858                 }
 859                 got_header = POST_HEADER;
 860                 tmp = *data;
 861             }
 862             continue;
 863         }
 864
 865         /* Check for end of stream (which means there is no header). */
 866         if (strncmp(linebuf, endstr, ENDLEN) == 0) {
 867             p = linebuf + ENDLEN;
 868             namelen = strlen(name);
 869             if (strncmp(p, name, namelen) != 0 ||
 870                 strncmp(p + namelen, tailstr, TAILLEN) != 0) {
 871                 PEMerr(PEM_F_GET_HEADER_AND_DATA, PEM_R_BAD_END_LINE);
 872                 goto err;
 873             }
 874             if (got_header == MAYBE_HEADER) {
 875                 *header = *data;
 876                 *data = tmp;
 877             }
 878             break;
 879         } else if (end) {
 880             /* Malformed input; short line not at end of data. */
 881             PEMerr(PEM_F_GET_HEADER_AND_DATA, PEM_R_BAD_END_LINE);
 882             goto err;
 883         }
 884         /*
 885          * Else, a line of text -- could be header or data; we don't
 886          * know yet.  Just pass it through.
 887          */
 888         if (BIO_puts(tmp, linebuf) < 0)
 889             goto err;
 890         /*
 891          * Only encrypted files need the line length check applied.
 892          */
 893         if (got_header == POST_HEADER) {
 894             /* 65 includes the trailing newline */
 895             if (len > 65)
 896                 goto err;
 897             if (len < 65)
 898                 end = 1;
 899         }
 900     }
 901
 902     ret = 1;
 903 err:
 904     pem_free(linebuf, flags, LINESIZE + 1);
 905     return ret;
 906 }
 907
 908 /**
 909  * Read in PEM-formatted data from the given BIO.
 910  *
 911  * By nature of the PEM format, all content must be printable ASCII (except
 912  * for line endings).  Other characters are malformed input and will be rejected.
 913  */
 914 int PEM_read_bio_ex(BIO *bp, char **name_out, char **header,
 915                     unsigned char **data, long *len_out, unsigned int flags)
 916 {
 917     EVP_ENCODE_CTX *ctx = EVP_ENCODE_CTX_new();
 918     const BIO_METHOD *bmeth;
 919     BIO *headerB = NULL, *dataB = NULL;
 920     char *name = NULL;
 921     int len, taillen, headerlen, ret = 0;
 922     BUF_MEM * buf_mem;
 923
 924     if (ctx == NULL) {
 925         PEMerr(PEM_F_PEM_READ_BIO_EX, ERR_R_MALLOC_FAILURE);
 926         return 0;
 927     }
 928
 929     *len_out = 0;
 930     *name_out = *header = NULL;
 931     *data = NULL;
 932     if ((flags & PEM_FLAG_EAY_COMPATIBLE) && (flags & PEM_FLAG_ONLY_B64)) {
 933         /* These two are mutually incompatible; bail out. */
 934         PEMerr(PEM_F_PEM_READ_BIO_EX, ERR_R_PASSED_INVALID_ARGUMENT);
 935         goto end;
 936     }
 937     bmeth = (flags & PEM_FLAG_SECURE) ? BIO_s_secmem() : BIO_s_mem();
 938
 939     headerB = BIO_new(bmeth);
 940     dataB = BIO_new(bmeth);
 941     if (headerB == NULL || dataB == NULL) {
 942         PEMerr(PEM_F_PEM_READ_BIO_EX, ERR_R_MALLOC_FAILURE);
 943         goto end;
 944     }
 945
 946     if (!get_name(bp, &name, flags))
 947         goto end;
 948     if (!get_header_and_data(bp, &headerB, &dataB, name, flags))
 949         goto end;
 950
 951     EVP_DecodeInit(ctx);
 952     BIO_get_mem_ptr(dataB, &buf_mem);
 953     len = buf_mem->length;
 954     if (EVP_DecodeUpdate(ctx, (unsigned char*)buf_mem->data, &len,
 955                          (unsigned char*)buf_mem->data, len) < 0
 956             || EVP_DecodeFinal(ctx, (unsigned char*)&(buf_mem->data[len]),
 957                                &taillen) < 0) {
 958         PEMerr(PEM_F_PEM_READ_BIO_EX, PEM_R_BAD_BASE64_DECODE);
 959         goto end;
 960     }
 961     len += taillen;
 962     buf_mem->length = len;
 963
 964     /* There was no data in the PEM file; avoid malloc(0). */
 965     if (len == 0)
 966         goto end;
 967     headerlen = BIO_get_mem_data(headerB, NULL);
 968     *header = pem_malloc(headerlen + 1, flags);
 969     *data = pem_malloc(len, flags);
 970     if (*header == NULL || *data == NULL) {
 971         pem_free(*header, flags, 0);
 972         pem_free(*data, flags, 0);
 973         goto end;
 974     }
 975     BIO_read(headerB, *header, headerlen);
 976     (*header)[headerlen] = '\0';
 977     BIO_read(dataB, *data, len);
 978     *len_out = len;
 979     *name_out = name;
 980     name = NULL;
 981     ret = 1;
 982
 983 end:
 984     EVP_ENCODE_CTX_free(ctx);
 985     pem_free(name, flags, 0);
 986     BIO_free(headerB);
 987     BIO_free(dataB);
 988     return ret;
 989 }
 990
 991 int PEM_read_bio(BIO *bp, char **name, char **header, unsigned char **data,
 992                  long *len)
 993 {
 994     return PEM_read_bio_ex(bp, name, header, data, len, PEM_FLAG_EAY_COMPATIBLE);
 995 }
 996
 997 /*
 998  * Check pem string and return prefix length. If for example the pem_str ==
 999  * "RSA PRIVATE KEY" and suffix = "PRIVATE KEY" the return value is 3 for the
1000  * string "RSA".
1001  */
1002
1003 int pem_check_suffix(const char *pem_str, const char *suffix)
1004 {
1005     int pem_len = strlen(pem_str);
1006     int suffix_len = strlen(suffix);
1007     const char *p;
1008     if (suffix_len + 1 >= pem_len)
1009         return 0;
1010     p = pem_str + pem_len - suffix_len;
1011     if (strcmp(p, suffix))
1012         return 0;
1013     p--;
1014     if (*p != ' ')
1015         return 0;
1016     return p - pem_str;
1017 }