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 /* We need to use some engine deprecated APIs */
  11 #define OPENSSL_SUPPRESS_DEPRECATED
  12
  13 #include <stdio.h>
  14 #include "crypto/ctype.h"
  15 #include <string.h>
  16 #include "internal/cryptlib.h"
  17 #include <openssl/buffer.h>
  18 #include <openssl/objects.h>
  19 #include <openssl/evp.h>
  20 #include <openssl/rand.h>
  21 #include <openssl/x509.h>
  22 #include <openssl/pem.h>
  23 #include <openssl/pkcs12.h>
  24 #include "crypto/asn1.h"
  25 #include <openssl/des.h>
  26 #include <openssl/engine.h>
  27
  28 #define MIN_LENGTH      4
  29
  30 static int load_iv(char **fromp, unsigned char *to, int num);
  31 static int check_pem(const char *nm, const char *name);
  32 int pem_check_suffix(const char *pem_str, const char *suffix);
  33
  34 int PEM_def_callback(char *buf, int num, int rwflag, void *userdata)
  35 {
  36     int i, min_len;
  37     const char *prompt;
  38
  39     /* We assume that the user passes a default password as userdata */
  40     if (userdata) {
  41         i = strlen(userdata);
  42         i = (i > num) ? num : i;
  43         memcpy(buf, userdata, i);
  44         return i;
  45     }
  46
  47     prompt = EVP_get_pw_prompt();
  48     if (prompt == NULL)
  49         prompt = "Enter PEM pass phrase:";
  50
  51     /*
  52      * rwflag == 0 means decryption
  53      * rwflag == 1 means encryption
  54      *
  55      * We assume that for encryption, we want a minimum length, while for
  56      * decryption, we cannot know any minimum length, so we assume zero.
  57      */
  58     min_len = rwflag ? MIN_LENGTH : 0;
  59
  60     i = EVP_read_pw_string_min(buf, min_len, num, prompt, rwflag);
  61     if (i != 0) {
  62         ERR_raise(ERR_LIB_PEM, PEM_R_PROBLEMS_GETTING_PASSWORD);
  63         memset(buf, 0, (unsigned int)num);
  64         return -1;
  65     }
  66     return strlen(buf);
  67 }
  68
  69 void PEM_proc_type(char *buf, int type)
  70 {
  71     const char *str;
  72     char *p = buf + strlen(buf);
  73
  74     if (type == PEM_TYPE_ENCRYPTED)
  75         str = "ENCRYPTED";
  76     else if (type == PEM_TYPE_MIC_CLEAR)
  77         str = "MIC-CLEAR";
  78     else if (type == PEM_TYPE_MIC_ONLY)
  79         str = "MIC-ONLY";
  80     else
  81         str = "BAD-TYPE";
  82
  83     BIO_snprintf(p, PEM_BUFSIZE - (size_t)(p - buf), "Proc-Type: 4,%s\n", str);
  84 }
  85
  86 void PEM_dek_info(char *buf, const char *type, int len, const char *str)
  87 {
  88     long i;
  89     char *p = buf + strlen(buf);
  90     int j = PEM_BUFSIZE - (size_t)(p - buf), n;
  91
  92     n = BIO_snprintf(p, j, "DEK-Info: %s,", type);
  93     if (n > 0) {
  94         j -= n;
  95         p += n;
  96         for (i = 0; i < len; i++) {
  97             n = BIO_snprintf(p, j, "%02X", 0xff & str[i]);
  98             if (n <= 0)
  99                 return;
 100             j -= n;
 101             p += n;
 102         }
 103         if (j > 1)
 104             strcpy(p, "\n");
 105     }
 106 }
 107
 108 #ifndef OPENSSL_NO_STDIO
 109 void *PEM_ASN1_read(d2i_of_void *d2i, const char *name, FILE *fp, void **x,
 110                     pem_password_cb *cb, void *u)
 111 {
 112     BIO *b;
 113     void *ret;
 114
 115     if ((b = BIO_new(BIO_s_file())) == NULL) {
 116         ERR_raise(ERR_LIB_PEM, ERR_R_BUF_LIB);
 117         return 0;
 118     }
 119     BIO_set_fp(b, fp, BIO_NOCLOSE);
 120     ret = PEM_ASN1_read_bio(d2i, name, b, x, cb, u);
 121     BIO_free(b);
 122     return ret;
 123 }
 124 #endif
 125
 126 static int check_pem(const char *nm, const char *name)
 127 {
 128     /* Normal matching nm and name */
 129     if (strcmp(nm, name) == 0)
 130         return 1;
 131
 132     /* Make PEM_STRING_EVP_PKEY match any private key */
 133
 134     if (strcmp(name, PEM_STRING_EVP_PKEY) == 0) {
 135         int slen;
 136         const EVP_PKEY_ASN1_METHOD *ameth;
 137         if (strcmp(nm, PEM_STRING_PKCS8) == 0)
 138             return 1;
 139         if (strcmp(nm, PEM_STRING_PKCS8INF) == 0)
 140             return 1;
 141         slen = pem_check_suffix(nm, "PRIVATE KEY");
 142         if (slen > 0) {
 143             /*
 144              * NB: ENGINE implementations won't contain a deprecated old
 145              * private key decode function so don't look for them.
 146              */
 147             ameth = EVP_PKEY_asn1_find_str(NULL, nm, slen);
 148             if (ameth && ameth->old_priv_decode)
 149                 return 1;
 150         }
 151         return 0;
 152     }
 153
 154     if (strcmp(name, PEM_STRING_PARAMETERS) == 0) {
 155         int slen;
 156         const EVP_PKEY_ASN1_METHOD *ameth;
 157         slen = pem_check_suffix(nm, "PARAMETERS");
 158         if (slen > 0) {
 159             ENGINE *e;
 160             ameth = EVP_PKEY_asn1_find_str(&e, nm, slen);
 161             if (ameth) {
 162                 int r;
 163                 if (ameth->param_decode)
 164                     r = 1;
 165                 else
 166                     r = 0;
 167 #ifndef OPENSSL_NO_ENGINE
 168                 ENGINE_finish(e);
 169 #endif
 170                 return r;
 171             }
 172         }
 173         return 0;
 174     }
 175     /* If reading DH parameters handle X9.42 DH format too */
 176     if (strcmp(nm, PEM_STRING_DHXPARAMS) == 0
 177         && strcmp(name, PEM_STRING_DHPARAMS) == 0)
 178         return 1;
 179
 180     /* Permit older strings */
 181
 182     if (strcmp(nm, PEM_STRING_X509_OLD) == 0
 183         && strcmp(name, PEM_STRING_X509) == 0)
 184         return 1;
 185
 186     if (strcmp(nm, PEM_STRING_X509_REQ_OLD) == 0
 187         && strcmp(name, PEM_STRING_X509_REQ) == 0)
 188         return 1;
 189
 190     /* Allow normal certs to be read as trusted certs */
 191     if (strcmp(nm, PEM_STRING_X509) == 0
 192         && strcmp(name, PEM_STRING_X509_TRUSTED) == 0)
 193         return 1;
 194
 195     if (strcmp(nm, PEM_STRING_X509_OLD) == 0
 196         && strcmp(name, PEM_STRING_X509_TRUSTED) == 0)
 197         return 1;
 198
 199     /* Some CAs use PKCS#7 with CERTIFICATE headers */
 200     if (strcmp(nm, PEM_STRING_X509) == 0
 201         && strcmp(name, PEM_STRING_PKCS7) == 0)
 202         return 1;
 203
 204     if (strcmp(nm, PEM_STRING_PKCS7_SIGNED) == 0
 205         && strcmp(name, PEM_STRING_PKCS7) == 0)
 206         return 1;
 207
 208 #ifndef OPENSSL_NO_CMS
 209     if (strcmp(nm, PEM_STRING_X509) == 0
 210         && strcmp(name, PEM_STRING_CMS) == 0)
 211         return 1;
 212     /* Allow CMS to be read from PKCS#7 headers */
 213     if (strcmp(nm, PEM_STRING_PKCS7) == 0
 214         && strcmp(name, PEM_STRING_CMS) == 0)
 215         return 1;
 216 #endif
 217
 218     return 0;
 219 }
 220
 221 static void pem_free(void *p, unsigned int flags, size_t num)
 222 {
 223     if (flags & PEM_FLAG_SECURE)
 224         OPENSSL_secure_clear_free(p, num);
 225     else
 226         OPENSSL_free(p);
 227 }
 228
 229 static void *pem_malloc(int num, unsigned int flags)
 230 {
 231     return (flags & PEM_FLAG_SECURE) ? OPENSSL_secure_malloc(num)
 232                                      : OPENSSL_malloc(num);
 233 }
 234
 235 static int pem_bytes_read_bio_flags(unsigned char **pdata, long *plen,
 236                                     char **pnm, const char *name, BIO *bp,
 237                                     pem_password_cb *cb, void *u,
 238                                     unsigned int flags)
 239 {
 240     EVP_CIPHER_INFO cipher;
 241     char *nm = NULL, *header = NULL;
 242     unsigned char *data = NULL;
 243     long len = 0;
 244     int ret = 0;
 245
 246     do {
 247         pem_free(nm, flags, 0);
 248         pem_free(header, flags, 0);
 249         pem_free(data, flags, len);
 250         if (!PEM_read_bio_ex(bp, &nm, &header, &data, &len, flags)) {
 251             if (ERR_GET_REASON(ERR_peek_error()) == PEM_R_NO_START_LINE)
 252                 ERR_add_error_data(2, "Expecting: ", name);
 253             return 0;
 254         }
 255     } while (!check_pem(nm, name));
 256     if (!PEM_get_EVP_CIPHER_INFO(header, &cipher))
 257         goto err;
 258     if (!PEM_do_header(&cipher, data, &len, cb, u))
 259         goto err;
 260
 261     *pdata = data;
 262     *plen = len;
 263
 264     if (pnm != NULL)
 265         *pnm = nm;
 266
 267     ret = 1;
 268
 269  err:
 270     if (!ret || pnm == NULL)
 271         pem_free(nm, flags, 0);
 272     pem_free(header, flags, 0);
 273     if (!ret)
 274         pem_free(data, flags, len);
 275     return ret;
 276 }
 277
 278 int PEM_bytes_read_bio(unsigned char **pdata, long *plen, char **pnm,
 279                        const char *name, BIO *bp, pem_password_cb *cb,
 280                        void *u) {
 281     return pem_bytes_read_bio_flags(pdata, plen, pnm, name, bp, cb, u,
 282                                     PEM_FLAG_EAY_COMPATIBLE);
 283 }
 284
 285 int PEM_bytes_read_bio_secmem(unsigned char **pdata, long *plen, char **pnm,
 286                               const char *name, BIO *bp, pem_password_cb *cb,
 287                               void *u) {
 288     return pem_bytes_read_bio_flags(pdata, plen, pnm, name, bp, cb, u,
 289                                     PEM_FLAG_SECURE | PEM_FLAG_EAY_COMPATIBLE);
 290 }
 291
 292 #ifndef OPENSSL_NO_STDIO
 293 int PEM_ASN1_write(i2d_of_void *i2d, const char *name, FILE *fp,
 294                    const void *x, const EVP_CIPHER *enc,
 295                    const unsigned char *kstr, int klen,
 296                    pem_password_cb *callback, void *u)
 297 {
 298     BIO *b;
 299     int ret;
 300
 301     if ((b = BIO_new(BIO_s_file())) == NULL) {
 302         ERR_raise(ERR_LIB_PEM, 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                        const void *x, const EVP_CIPHER *enc,
 314                        const unsigned char *kstr, int klen,
 315                        pem_password_cb *callback, void *u)
 316 {
 317     EVP_CIPHER_CTX *ctx = NULL;
 318     int dsize = 0, i = 0, j = 0, ret = 0;
 319     unsigned char *p, *data = NULL;
 320     const char *objstr = NULL;
 321     char buf[PEM_BUFSIZE];
 322     unsigned char key[EVP_MAX_KEY_LENGTH];
 323     unsigned char iv[EVP_MAX_IV_LENGTH];
 324
 325     if (enc != NULL) {
 326         objstr = OBJ_nid2sn(EVP_CIPHER_nid(enc));
 327         if (objstr == NULL || EVP_CIPHER_iv_length(enc) == 0
 328                 || EVP_CIPHER_iv_length(enc) > (int)sizeof(iv)
 329                    /*
 330                     * Check "Proc-Type: 4,Encrypted\nDEK-Info: objstr,hex-iv\n"
 331                     * fits into buf
 332                     */
 333                 || (strlen(objstr) + 23 + 2 * EVP_CIPHER_iv_length(enc) + 13)
 334                    > sizeof(buf)) {
 335             ERR_raise(ERR_LIB_PEM, PEM_R_UNSUPPORTED_CIPHER);
 336             goto err;
 337         }
 338     }
 339
 340     if ((dsize = i2d(x, NULL)) <= 0) {
 341         ERR_raise(ERR_LIB_PEM, ERR_R_ASN1_LIB);
 342         dsize = 0;
 343         goto err;
 344     }
 345     /* dsize + 8 bytes are needed */
 346     /* actually it needs the cipher block size extra... */
 347     data = OPENSSL_malloc((unsigned int)dsize + 20);
 348     if (data == NULL) {
 349         ERR_raise(ERR_LIB_PEM, ERR_R_MALLOC_FAILURE);
 350         goto err;
 351     }
 352     p = data;
 353     i = i2d(x, &p);
 354
 355     if (enc != NULL) {
 356         if (kstr == NULL) {
 357             if (callback == NULL)
 358                 klen = PEM_def_callback(buf, PEM_BUFSIZE, 1, u);
 359             else
 360                 klen = (*callback) (buf, PEM_BUFSIZE, 1, u);
 361             if (klen <= 0) {
 362                 ERR_raise(ERR_LIB_PEM, PEM_R_READ_KEY);
 363                 goto err;
 364             }
 365 #ifdef CHARSET_EBCDIC
 366             /* Convert the pass phrase from EBCDIC */
 367             ebcdic2ascii(buf, buf, klen);
 368 #endif
 369             kstr = (unsigned char *)buf;
 370         }
 371         if (RAND_bytes(iv, EVP_CIPHER_iv_length(enc)) <= 0) /* Generate a salt */
 372             goto err;
 373         /*
 374          * The 'iv' is used as the iv and as a salt.  It is NOT taken from
 375          * the BytesToKey function
 376          */
 377         if (!EVP_BytesToKey(enc, EVP_md5(), iv, kstr, klen, 1, key, NULL))
 378             goto err;
 379
 380         if (kstr == (unsigned char *)buf)
 381             OPENSSL_cleanse(buf, PEM_BUFSIZE);
 382
 383         buf[0] = '\0';
 384         PEM_proc_type(buf, PEM_TYPE_ENCRYPTED);
 385         PEM_dek_info(buf, objstr, EVP_CIPHER_iv_length(enc), (char *)iv);
 386         /* k=strlen(buf); */
 387
 388         ret = 1;
 389         if ((ctx = EVP_CIPHER_CTX_new()) == NULL
 390             || !EVP_EncryptInit_ex(ctx, enc, NULL, key, iv)
 391             || !EVP_EncryptUpdate(ctx, data, &j, data, i)
 392             || !EVP_EncryptFinal_ex(ctx, &(data[j]), &i))
 393             ret = 0;
 394         if (ret == 0)
 395             goto err;
 396         i += j;
 397     } else {
 398         ret = 1;
 399         buf[0] = '\0';
 400     }
 401     i = PEM_write_bio(bp, name, buf, data, i);
 402     if (i <= 0)
 403         ret = 0;
 404  err:
 405     OPENSSL_cleanse(key, sizeof(key));
 406     OPENSSL_cleanse(iv, sizeof(iv));
 407     EVP_CIPHER_CTX_free(ctx);
 408     OPENSSL_cleanse(buf, PEM_BUFSIZE);
 409     OPENSSL_clear_free(data, (unsigned int)dsize);
 410     return ret;
 411 }
 412
 413 int PEM_do_header(EVP_CIPHER_INFO *cipher, unsigned char *data, long *plen,
 414                   pem_password_cb *callback, void *u)
 415 {
 416     int ok;
 417     int keylen;
 418     long len = *plen;
 419     int ilen = (int) len;       /* EVP_DecryptUpdate etc. take int lengths */
 420     EVP_CIPHER_CTX *ctx;
 421     unsigned char key[EVP_MAX_KEY_LENGTH];
 422     char buf[PEM_BUFSIZE];
 423
 424 #if LONG_MAX > INT_MAX
 425     /* Check that we did not truncate the length */
 426     if (len > INT_MAX) {
 427         ERR_raise(ERR_LIB_PEM, PEM_R_HEADER_TOO_LONG);
 428         return 0;
 429     }
 430 #endif
 431
 432     if (cipher->cipher == NULL)
 433         return 1;
 434     if (callback == NULL)
 435         keylen = PEM_def_callback(buf, PEM_BUFSIZE, 0, u);
 436     else
 437         keylen = callback(buf, PEM_BUFSIZE, 0, u);
 438     if (keylen < 0) {
 439         ERR_raise(ERR_LIB_PEM, PEM_R_BAD_PASSWORD_READ);
 440         return 0;
 441     }
 442 #ifdef CHARSET_EBCDIC
 443     /* Convert the pass phrase from EBCDIC */
 444     ebcdic2ascii(buf, buf, keylen);
 445 #endif
 446
 447     if (!EVP_BytesToKey(cipher->cipher, EVP_md5(), &(cipher->iv[0]),
 448                         (unsigned char *)buf, keylen, 1, key, NULL))
 449         return 0;
 450
 451     ctx = EVP_CIPHER_CTX_new();
 452     if (ctx == NULL)
 453         return 0;
 454
 455     ok = EVP_DecryptInit_ex(ctx, cipher->cipher, NULL, key, &(cipher->iv[0]));
 456     if (ok)
 457         ok = EVP_DecryptUpdate(ctx, data, &ilen, data, ilen);
 458     if (ok) {
 459         /* Squirrel away the length of data decrypted so far. */
 460         *plen = ilen;
 461         ok = EVP_DecryptFinal_ex(ctx, &(data[ilen]), &ilen);
 462     }
 463     if (ok)
 464         *plen += ilen;
 465     else
 466         ERR_raise(ERR_LIB_PEM, PEM_R_BAD_DECRYPT);
 467
 468     EVP_CIPHER_CTX_free(ctx);
 469     OPENSSL_cleanse((char *)buf, sizeof(buf));
 470     OPENSSL_cleanse((char *)key, sizeof(key));
 471     return ok;
 472 }
 473
 474 /*
 475  * This implements a very limited PEM header parser that does not support the
 476  * full grammar of rfc1421.  In particular, folded headers are not supported,
 477  * nor is additional whitespace.
 478  *
 479  * A robust implementation would make use of a library that turns the headers
 480  * into a BIO from which one folded line is read at a time, and is then split
 481  * into a header label and content.  We would then parse the content of the
 482  * headers we care about.  This is overkill for just this limited use-case, but
 483  * presumably we also parse rfc822-style headers for S/MIME, so a common
 484  * abstraction might well be more generally useful.
 485  */
 486 int PEM_get_EVP_CIPHER_INFO(char *header, EVP_CIPHER_INFO *cipher)
 487 {
 488     static const char ProcType[] = "Proc-Type:";
 489     static const char ENCRYPTED[] = "ENCRYPTED";
 490     static const char DEKInfo[] = "DEK-Info:";
 491     const EVP_CIPHER *enc = NULL;
 492     int ivlen;
 493     char *dekinfostart, c;
 494
 495     cipher->cipher = NULL;
 496     memset(cipher->iv, 0, sizeof(cipher->iv));
 497     if ((header == NULL) || (*header == '\0') || (*header == '\n'))
 498         return 1;
 499
 500     if (strncmp(header, ProcType, sizeof(ProcType)-1) != 0) {
 501         ERR_raise(ERR_LIB_PEM, PEM_R_NOT_PROC_TYPE);
 502         return 0;
 503     }
 504     header += sizeof(ProcType)-1;
 505     header += strspn(header, " \t");
 506
 507     if (*header++ != '4' || *header++ != ',')
 508         return 0;
 509     header += strspn(header, " \t");
 510
 511     /* We expect "ENCRYPTED" followed by optional white-space + line break */
 512     if (strncmp(header, ENCRYPTED, sizeof(ENCRYPTED)-1) != 0 ||
 513         strspn(header+sizeof(ENCRYPTED)-1, " \t\r\n") == 0) {
 514         ERR_raise(ERR_LIB_PEM, PEM_R_NOT_ENCRYPTED);
 515         return 0;
 516     }
 517     header += sizeof(ENCRYPTED)-1;
 518     header += strspn(header, " \t\r");
 519     if (*header++ != '\n') {
 520         ERR_raise(ERR_LIB_PEM, PEM_R_SHORT_HEADER);
 521         return 0;
 522     }
 523
 524     /*-
 525      * https://tools.ietf.org/html/rfc1421#section-4.6.1.3
 526      * We expect "DEK-Info: algo[,hex-parameters]"
 527      */
 528     if (strncmp(header, DEKInfo, sizeof(DEKInfo)-1) != 0) {
 529         ERR_raise(ERR_LIB_PEM, PEM_R_NOT_DEK_INFO);
 530         return 0;
 531     }
 532     header += sizeof(DEKInfo)-1;
 533     header += strspn(header, " \t");
 534
 535     /*
 536      * DEK-INFO is a comma-separated combination of algorithm name and optional
 537      * parameters.
 538      */
 539     dekinfostart = header;
 540     header += strcspn(header, " \t,");
 541     c = *header;
 542     *header = '\0';
 543     cipher->cipher = enc = EVP_get_cipherbyname(dekinfostart);
 544     *header = c;
 545     header += strspn(header, " \t");
 546
 547     if (enc == NULL) {
 548         ERR_raise(ERR_LIB_PEM, PEM_R_UNSUPPORTED_ENCRYPTION);
 549         return 0;
 550     }
 551     ivlen = EVP_CIPHER_iv_length(enc);
 552     if (ivlen > 0 && *header++ != ',') {
 553         ERR_raise(ERR_LIB_PEM, PEM_R_MISSING_DEK_IV);
 554         return 0;
 555     } else if (ivlen == 0 && *header == ',') {
 556         ERR_raise(ERR_LIB_PEM, PEM_R_UNEXPECTED_DEK_IV);
 557         return 0;
 558     }
 559
 560     if (!load_iv(&header, cipher->iv, EVP_CIPHER_iv_length(enc)))
 561         return 0;
 562
 563     return 1;
 564 }
 565
 566 static int load_iv(char **fromp, unsigned char *to, int num)
 567 {
 568     int v, i;
 569     char *from;
 570
 571     from = *fromp;
 572     for (i = 0; i < num; i++)
 573         to[i] = 0;
 574     num *= 2;
 575     for (i = 0; i < num; i++) {
 576         v = OPENSSL_hexchar2int(*from);
 577         if (v < 0) {
 578             ERR_raise(ERR_LIB_PEM, PEM_R_BAD_IV_CHARS);
 579             return 0;
 580         }
 581         from++;
 582         to[i / 2] |= v << (long)((!(i & 1)) * 4);
 583     }
 584
 585     *fromp = from;
 586     return 1;
 587 }
 588
 589 #ifndef OPENSSL_NO_STDIO
 590 int PEM_write(FILE *fp, const char *name, const char *header,
 591               const unsigned char *data, long len)
 592 {
 593     BIO *b;
 594     int ret;
 595
 596     if ((b = BIO_new(BIO_s_file())) == NULL) {
 597         ERR_raise(ERR_LIB_PEM, ERR_R_BUF_LIB);
 598         return 0;
 599     }
 600     BIO_set_fp(b, fp, BIO_NOCLOSE);
 601     ret = PEM_write_bio(b, name, header, data, len);
 602     BIO_free(b);
 603     return ret;
 604 }
 605 #endif
 606
 607 int PEM_write_bio(BIO *bp, const char *name, const char *header,
 608                   const unsigned char *data, long len)
 609 {
 610     int nlen, n, i, j, outl;
 611     unsigned char *buf = NULL;
 612     EVP_ENCODE_CTX *ctx = EVP_ENCODE_CTX_new();
 613     int reason = ERR_R_BUF_LIB;
 614     int retval = 0;
 615
 616     if (ctx == NULL) {
 617         reason = ERR_R_MALLOC_FAILURE;
 618         goto err;
 619     }
 620
 621     EVP_EncodeInit(ctx);
 622     nlen = strlen(name);
 623
 624     if ((BIO_write(bp, "-----BEGIN ", 11) != 11) ||
 625         (BIO_write(bp, name, nlen) != nlen) ||
 626         (BIO_write(bp, "-----\n", 6) != 6))
 627         goto err;
 628
 629     i = strlen(header);
 630     if (i > 0) {
 631         if ((BIO_write(bp, header, i) != i) || (BIO_write(bp, "\n", 1) != 1))
 632             goto err;
 633     }
 634
 635     buf = OPENSSL_malloc(PEM_BUFSIZE * 8);
 636     if (buf == NULL) {
 637         reason = ERR_R_MALLOC_FAILURE;
 638         goto err;
 639     }
 640
 641     i = j = 0;
 642     while (len > 0) {
 643         n = (int)((len > (PEM_BUFSIZE * 5)) ? (PEM_BUFSIZE * 5) : len);
 644         if (!EVP_EncodeUpdate(ctx, buf, &outl, &(data[j]), n))
 645             goto err;
 646         if ((outl) && (BIO_write(bp, (char *)buf, outl) != outl))
 647             goto err;
 648         i += outl;
 649         len -= n;
 650         j += n;
 651     }
 652     EVP_EncodeFinal(ctx, buf, &outl);
 653     if ((outl > 0) && (BIO_write(bp, (char *)buf, outl) != outl))
 654         goto err;
 655     if ((BIO_write(bp, "-----END ", 9) != 9) ||
 656         (BIO_write(bp, name, nlen) != nlen) ||
 657         (BIO_write(bp, "-----\n", 6) != 6))
 658         goto err;
 659     retval = i + outl;
 660
 661  err:
 662     if (retval == 0)
 663         ERR_raise(ERR_LIB_PEM, reason);
 664     EVP_ENCODE_CTX_free(ctx);
 665     OPENSSL_clear_free(buf, PEM_BUFSIZE * 8);
 666     return retval;
 667 }
 668
 669 #ifndef OPENSSL_NO_STDIO
 670 int PEM_read(FILE *fp, char **name, char **header, unsigned char **data,
 671              long *len)
 672 {
 673     BIO *b;
 674     int ret;
 675
 676     if ((b = BIO_new(BIO_s_file())) == NULL) {
 677         ERR_raise(ERR_LIB_PEM, ERR_R_BUF_LIB);
 678         return 0;
 679     }
 680     BIO_set_fp(b, fp, BIO_NOCLOSE);
 681     ret = PEM_read_bio(b, name, header, data, len);
 682     BIO_free(b);
 683     return ret;
 684 }
 685 #endif
 686
 687 /* Some helpers for PEM_read_bio_ex(). */
 688 static int sanitize_line(char *linebuf, int len, unsigned int flags, int first_call)
 689 {
 690     int i;
 691     if (first_call) {
 692         /* Other BOMs imply unsupported multibyte encoding,
 693          * so don't strip them and let the error raise */
 694         const unsigned char utf8_bom[3] = {0xEF, 0xBB, 0xBF};
 695
 696         if (len > 3 && memcmp(linebuf, utf8_bom, 3) == 0) {
 697             memmove(linebuf, linebuf + 3, len - 3);
 698             linebuf[len - 3] = 0;
 699             len -= 3;
 700         }
 701     }
 702
 703     if (flags & PEM_FLAG_EAY_COMPATIBLE) {
 704         /* Strip trailing whitespace */
 705         while ((len >= 0) && (linebuf[len] <= ' '))
 706             len--;
 707         /* Go back to whitespace before applying uniform line ending. */
 708         len++;
 709     } else if (flags & PEM_FLAG_ONLY_B64) {
 710         for (i = 0; i < len; ++i) {
 711             if (!ossl_isbase64(linebuf[i]) || linebuf[i] == '\n'
 712                 || linebuf[i] == '\r')
 713                 break;
 714         }
 715         len = i;
 716     } else {
 717         /* EVP_DecodeBlock strips leading and trailing whitespace, so just strip
 718          * control characters in-place and let everything through. */
 719         for (i = 0; i < len; ++i) {
 720             if (linebuf[i] == '\n' || linebuf[i] == '\r')
 721                 break;
 722             if (ossl_iscntrl(linebuf[i]))
 723                 linebuf[i] = ' ';
 724         }
 725         len = i;
 726     }
 727     /* The caller allocated LINESIZE+1, so this is safe. */
 728     linebuf[len++] = '\n';
 729     linebuf[len] = '\0';
 730     return len;
 731 }
 732
 733 #define LINESIZE 255
 734 /* Note trailing spaces for begin and end. */
 735 static const char beginstr[] = "-----BEGIN ";
 736 static const char endstr[] = "-----END ";
 737 static const char tailstr[] = "-----\n";
 738 #define BEGINLEN ((int)(sizeof(beginstr) - 1))
 739 #define ENDLEN ((int)(sizeof(endstr) - 1))
 740 #define TAILLEN ((int)(sizeof(tailstr) - 1))
 741 static int get_name(BIO *bp, char **name, unsigned int flags)
 742 {
 743     char *linebuf;
 744     int ret = 0;
 745     int len;
 746     int first_call = 1;
 747
 748     /*
 749      * Need to hold trailing NUL (accounted for by BIO_gets() and the newline
 750      * that will be added by sanitize_line() (the extra '1').
 751      */
 752     linebuf = pem_malloc(LINESIZE + 1, flags);
 753     if (linebuf == NULL) {
 754         ERR_raise(ERR_LIB_PEM, ERR_R_MALLOC_FAILURE);
 755         return 0;
 756     }
 757
 758     do {
 759         len = BIO_gets(bp, linebuf, LINESIZE);
 760
 761         if (len <= 0) {
 762             ERR_raise(ERR_LIB_PEM, PEM_R_NO_START_LINE);
 763             goto err;
 764         }
 765
 766         /* Strip trailing garbage and standardize ending. */
 767         len = sanitize_line(linebuf, len, flags & ~PEM_FLAG_ONLY_B64, first_call);
 768         first_call = 0;
 769
 770         /* Allow leading empty or non-matching lines. */
 771     } while (strncmp(linebuf, beginstr, BEGINLEN) != 0
 772              || len < TAILLEN
 773              || strncmp(linebuf + len - TAILLEN, tailstr, TAILLEN) != 0);
 774     linebuf[len - TAILLEN] = '\0';
 775     len = len - BEGINLEN - TAILLEN + 1;
 776     *name = pem_malloc(len, flags);
 777     if (*name == NULL) {
 778         ERR_raise(ERR_LIB_PEM, ERR_R_MALLOC_FAILURE);
 779         goto err;
 780     }
 781     memcpy(*name, linebuf + BEGINLEN, len);
 782     ret = 1;
 783
 784 err:
 785     pem_free(linebuf, flags, LINESIZE + 1);
 786     return ret;
 787 }
 788
 789 /* Keep track of how much of a header we've seen. */
 790 enum header_status {
 791     MAYBE_HEADER,
 792     IN_HEADER,
 793     POST_HEADER
 794 };
 795
 796 /**
 797  * Extract the optional PEM header, with details on the type of content and
 798  * any encryption used on the contents, and the bulk of the data from the bio.
 799  * The end of the header is marked by a blank line; if the end-of-input marker
 800  * is reached prior to a blank line, there is no header.
 801  *
 802  * The header and data arguments are BIO** since we may have to swap them
 803  * if there is no header, for efficiency.
 804  *
 805  * We need the name of the PEM-encoded type to verify the end string.
 806  */
 807 static int get_header_and_data(BIO *bp, BIO **header, BIO **data, char *name,
 808                                unsigned int flags)
 809 {
 810     BIO *tmp = *header;
 811     char *linebuf, *p;
 812     int len, line, ret = 0, end = 0, prev_partial_line_read = 0, partial_line_read = 0;
 813     /* 0 if not seen (yet), 1 if reading header, 2 if finished header */
 814     enum header_status got_header = MAYBE_HEADER;
 815     unsigned int flags_mask;
 816     size_t namelen;
 817
 818     /* Need to hold trailing NUL (accounted for by BIO_gets() and the newline
 819      * that will be added by sanitize_line() (the extra '1'). */
 820     linebuf = pem_malloc(LINESIZE + 1, flags);
 821     if (linebuf == NULL) {
 822         ERR_raise(ERR_LIB_PEM, ERR_R_MALLOC_FAILURE);
 823         return 0;
 824     }
 825
 826     for (line = 0; ; line++) {
 827         flags_mask = ~0u;
 828         len = BIO_gets(bp, linebuf, LINESIZE);
 829         if (len <= 0) {
 830             ERR_raise(ERR_LIB_PEM, PEM_R_BAD_END_LINE);
 831             goto err;
 832         }
 833
 834         /*
 835          * Check if line has been read completely or if only part of the line
 836          * has been read. Keep the previous value to ignore newlines that
 837          * appear due to reading a line up until the char before the newline.
 838          */
 839         prev_partial_line_read = partial_line_read;
 840         partial_line_read = len == LINESIZE-1 && linebuf[LINESIZE-2] != '\n';
 841
 842         if (got_header == MAYBE_HEADER) {
 843             if (memchr(linebuf, ':', len) != NULL)
 844                 got_header = IN_HEADER;
 845         }
 846         if (!strncmp(linebuf, endstr, ENDLEN) || got_header == IN_HEADER)
 847             flags_mask &= ~PEM_FLAG_ONLY_B64;
 848         len = sanitize_line(linebuf, len, flags & flags_mask, 0);
 849
 850         /* Check for end of header. */
 851         if (linebuf[0] == '\n') {
 852             /*
 853              * If previous line has been read only partially this newline is a
 854              * regular newline at the end of a line and not an empty line.
 855              */
 856             if (!prev_partial_line_read) {
 857                 if (got_header == POST_HEADER) {
 858                     /* Another blank line is an error. */
 859                     ERR_raise(ERR_LIB_PEM, PEM_R_BAD_END_LINE);
 860                     goto err;
 861                 }
 862                 got_header = POST_HEADER;
 863                 tmp = *data;
 864             }
 865             continue;
 866         }
 867
 868         /* Check for end of stream (which means there is no header). */
 869         if (strncmp(linebuf, endstr, ENDLEN) == 0) {
 870             p = linebuf + ENDLEN;
 871             namelen = strlen(name);
 872             if (strncmp(p, name, namelen) != 0 ||
 873                 strncmp(p + namelen, tailstr, TAILLEN) != 0) {
 874                 ERR_raise(ERR_LIB_PEM, PEM_R_BAD_END_LINE);
 875                 goto err;
 876             }
 877             if (got_header == MAYBE_HEADER) {
 878                 *header = *data;
 879                 *data = tmp;
 880             }
 881             break;
 882         } else if (end) {
 883             /* Malformed input; short line not at end of data. */
 884             ERR_raise(ERR_LIB_PEM, PEM_R_BAD_END_LINE);
 885             goto err;
 886         }
 887         /*
 888          * Else, a line of text -- could be header or data; we don't
 889          * know yet.  Just pass it through.
 890          */
 891         if (BIO_puts(tmp, linebuf) < 0)
 892             goto err;
 893         /*
 894          * Only encrypted files need the line length check applied.
 895          */
 896         if (got_header == POST_HEADER) {
 897             /* 65 includes the trailing newline */
 898             if (len > 65)
 899                 goto err;
 900             if (len < 65)
 901                 end = 1;
 902         }
 903     }
 904
 905     ret = 1;
 906 err:
 907     pem_free(linebuf, flags, LINESIZE + 1);
 908     return ret;
 909 }
 910
 911 /**
 912  * Read in PEM-formatted data from the given BIO.
 913  *
 914  * By nature of the PEM format, all content must be printable ASCII (except
 915  * for line endings).  Other characters are malformed input and will be rejected.
 916  */
 917 int PEM_read_bio_ex(BIO *bp, char **name_out, char **header,
 918                     unsigned char **data, long *len_out, unsigned int flags)
 919 {
 920     EVP_ENCODE_CTX *ctx = NULL;
 921     const BIO_METHOD *bmeth;
 922     BIO *headerB = NULL, *dataB = NULL;
 923     char *name = NULL;
 924     int len, taillen, headerlen, ret = 0;
 925     BUF_MEM * buf_mem;
 926
 927     *len_out = 0;
 928     *name_out = *header = NULL;
 929     *data = NULL;
 930     if ((flags & PEM_FLAG_EAY_COMPATIBLE) && (flags & PEM_FLAG_ONLY_B64)) {
 931         /* These two are mutually incompatible; bail out. */
 932         ERR_raise(ERR_LIB_PEM, ERR_R_PASSED_INVALID_ARGUMENT);
 933         goto end;
 934     }
 935     bmeth = (flags & PEM_FLAG_SECURE) ? BIO_s_secmem() : BIO_s_mem();
 936
 937     headerB = BIO_new(bmeth);
 938     dataB = BIO_new(bmeth);
 939     if (headerB == NULL || dataB == NULL) {
 940         ERR_raise(ERR_LIB_PEM, ERR_R_MALLOC_FAILURE);
 941         goto end;
 942     }
 943
 944     if (!get_name(bp, &name, flags))
 945         goto end;
 946     if (!get_header_and_data(bp, &headerB, &dataB, name, flags))
 947         goto end;
 948
 949     BIO_get_mem_ptr(dataB, &buf_mem);
 950     len = buf_mem->length;
 951
 952     /* There was no data in the PEM file */
 953     if (len == 0)
 954         goto end;
 955
 956     ctx = EVP_ENCODE_CTX_new();
 957     if (ctx == NULL) {
 958         ERR_raise(ERR_LIB_PEM, ERR_R_MALLOC_FAILURE);
 959         goto end;
 960     }
 961
 962     EVP_DecodeInit(ctx);
 963     if (EVP_DecodeUpdate(ctx, (unsigned char*)buf_mem->data, &len,
 964                          (unsigned char*)buf_mem->data, len) < 0
 965             || EVP_DecodeFinal(ctx, (unsigned char*)&(buf_mem->data[len]),
 966                                &taillen) < 0) {
 967         ERR_raise(ERR_LIB_PEM, PEM_R_BAD_BASE64_DECODE);
 968         goto end;
 969     }
 970     len += taillen;
 971     buf_mem->length = len;
 972
 973     headerlen = BIO_get_mem_data(headerB, NULL);
 974     *header = pem_malloc(headerlen + 1, flags);
 975     *data = pem_malloc(len, flags);
 976     if (*header == NULL || *data == NULL) {
 977         pem_free(*header, flags, 0);
 978         pem_free(*data, flags, 0);
 979         goto end;
 980     }
 981     BIO_read(headerB, *header, headerlen);
 982     (*header)[headerlen] = '\0';
 983     BIO_read(dataB, *data, len);
 984     *len_out = len;
 985     *name_out = name;
 986     name = NULL;
 987     ret = 1;
 988
 989 end:
 990     EVP_ENCODE_CTX_free(ctx);
 991     pem_free(name, flags, 0);
 992     BIO_free(headerB);
 993     BIO_free(dataB);
 994     return ret;
 995 }
 996
 997 int PEM_read_bio(BIO *bp, char **name, char **header, unsigned char **data,
 998                  long *len)
 999 {
1000     return PEM_read_bio_ex(bp, name, header, data, len, PEM_FLAG_EAY_COMPATIBLE);
1001 }
1002
1003 /*
1004  * Check pem string and return prefix length. If for example the pem_str ==
1005  * "RSA PRIVATE KEY" and suffix = "PRIVATE KEY" the return value is 3 for the
1006  * string "RSA".
1007  */
1008
1009 int pem_check_suffix(const char *pem_str, const char *suffix)
1010 {
1011     int pem_len = strlen(pem_str);
1012     int suffix_len = strlen(suffix);
1013     const char *p;
1014     if (suffix_len + 1 >= pem_len)
1015         return 0;
1016     p = pem_str + pem_len - suffix_len;
1017     if (strcmp(p, suffix))
1018         return 0;
1019     p--;
1020     if (*p != ' ')
1021         return 0;
1022     return p - pem_str;
1023 }