crypto/pem/pem_lib.c

   1 /*
   2  * Copyright 1995-2023 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 ossl_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 = ossl_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 = ossl_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 #define PEM_FREE(p, flags, num)                                 \
 222     pem_free((p), (flags), (num), OPENSSL_FILE, OPENSSL_LINE)
 223 static void pem_free(void *p, unsigned int flags, size_t num,
 224                      const char *file, int line)
 225 {
 226     if (flags & PEM_FLAG_SECURE)
 227         CRYPTO_secure_clear_free(p, num, file, line);
 228     else
 229         CRYPTO_free(p, file, line);
 230 }
 231
 232 #define PEM_MALLOC(num, flags)                                  \
 233     pem_malloc((num), (flags), OPENSSL_FILE, OPENSSL_LINE)
 234 static void *pem_malloc(int num, unsigned int flags,
 235                         const char *file, int line)
 236 {
 237     return (flags & PEM_FLAG_SECURE) ? CRYPTO_secure_malloc(num, file, line)
 238                                      : CRYPTO_malloc(num, file, line);
 239
 240 }
 241
 242 static int pem_bytes_read_bio_flags(unsigned char **pdata, long *plen,
 243                                     char **pnm, const char *name, BIO *bp,
 244                                     pem_password_cb *cb, void *u,
 245                                     unsigned int flags)
 246 {
 247     EVP_CIPHER_INFO cipher;
 248     char *nm = NULL, *header = NULL;
 249     unsigned char *data = NULL;
 250     long len = 0;
 251     int ret = 0;
 252
 253     do {
 254         PEM_FREE(nm, flags, 0);
 255         PEM_FREE(header, flags, 0);
 256         PEM_FREE(data, flags, len);
 257         if (!PEM_read_bio_ex(bp, &nm, &header, &data, &len, flags)) {
 258             if (ERR_GET_REASON(ERR_peek_error()) == PEM_R_NO_START_LINE)
 259                 ERR_add_error_data(2, "Expecting: ", name);
 260             return 0;
 261         }
 262     } while (!check_pem(nm, name));
 263     if (!PEM_get_EVP_CIPHER_INFO(header, &cipher))
 264         goto err;
 265     if (!PEM_do_header(&cipher, data, &len, cb, u))
 266         goto err;
 267
 268     *pdata = data;
 269     *plen = len;
 270
 271     if (pnm != NULL)
 272         *pnm = nm;
 273
 274     ret = 1;
 275
 276  err:
 277     if (!ret || pnm == NULL)
 278         PEM_FREE(nm, flags, 0);
 279     PEM_FREE(header, flags, 0);
 280     if (!ret)
 281         PEM_FREE(data, flags, len);
 282     return ret;
 283 }
 284
 285 int PEM_bytes_read_bio(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_EAY_COMPATIBLE);
 290 }
 291
 292 int PEM_bytes_read_bio_secmem(unsigned char **pdata, long *plen, char **pnm,
 293                               const char *name, BIO *bp, pem_password_cb *cb,
 294                               void *u) {
 295     return pem_bytes_read_bio_flags(pdata, plen, pnm, name, bp, cb, u,
 296                                     PEM_FLAG_SECURE | PEM_FLAG_EAY_COMPATIBLE);
 297 }
 298
 299 #ifndef OPENSSL_NO_STDIO
 300 int PEM_ASN1_write(i2d_of_void *i2d, const char *name, FILE *fp,
 301                    const void *x, const EVP_CIPHER *enc,
 302                    const unsigned char *kstr, int klen,
 303                    pem_password_cb *callback, void *u)
 304 {
 305     BIO *b;
 306     int ret;
 307
 308     if ((b = BIO_new(BIO_s_file())) == NULL) {
 309         ERR_raise(ERR_LIB_PEM, ERR_R_BUF_LIB);
 310         return 0;
 311     }
 312     BIO_set_fp(b, fp, BIO_NOCLOSE);
 313     ret = PEM_ASN1_write_bio(i2d, name, b, x, enc, kstr, klen, callback, u);
 314     BIO_free(b);
 315     return ret;
 316 }
 317 #endif
 318
 319 int PEM_ASN1_write_bio(i2d_of_void *i2d, const char *name, BIO *bp,
 320                        const void *x, const EVP_CIPHER *enc,
 321                        const unsigned char *kstr, int klen,
 322                        pem_password_cb *callback, void *u)
 323 {
 324     EVP_CIPHER_CTX *ctx = NULL;
 325     int dsize = 0, i = 0, j = 0, ret = 0;
 326     unsigned char *p, *data = NULL;
 327     const char *objstr = NULL;
 328     char buf[PEM_BUFSIZE];
 329     unsigned char key[EVP_MAX_KEY_LENGTH];
 330     unsigned char iv[EVP_MAX_IV_LENGTH];
 331
 332     if (enc != NULL) {
 333         objstr = EVP_CIPHER_get0_name(enc);
 334         if (objstr == NULL || EVP_CIPHER_get_iv_length(enc) == 0
 335                 || EVP_CIPHER_get_iv_length(enc) > (int)sizeof(iv)
 336                    /*
 337                     * Check "Proc-Type: 4,Encrypted\nDEK-Info: objstr,hex-iv\n"
 338                     * fits into buf
 339                     */
 340                 || strlen(objstr) + 23 + 2 * EVP_CIPHER_get_iv_length(enc) + 13
 341                    > sizeof(buf)) {
 342             ERR_raise(ERR_LIB_PEM, PEM_R_UNSUPPORTED_CIPHER);
 343             goto err;
 344         }
 345     }
 346
 347     if ((dsize = i2d(x, NULL)) <= 0) {
 348         ERR_raise(ERR_LIB_PEM, ERR_R_ASN1_LIB);
 349         dsize = 0;
 350         goto err;
 351     }
 352     /* dsize + 8 bytes are needed */
 353     /* actually it needs the cipher block size extra... */
 354     data = OPENSSL_malloc((unsigned int)dsize + 20);
 355     if (data == NULL)
 356         goto err;
 357     p = data;
 358     i = i2d(x, &p);
 359
 360     if (enc != NULL) {
 361         if (kstr == NULL) {
 362             if (callback == NULL)
 363                 klen = PEM_def_callback(buf, PEM_BUFSIZE, 1, u);
 364             else
 365                 klen = (*callback) (buf, PEM_BUFSIZE, 1, u);
 366             if (klen <= 0) {
 367                 ERR_raise(ERR_LIB_PEM, PEM_R_READ_KEY);
 368                 goto err;
 369             }
 370 #ifdef CHARSET_EBCDIC
 371             /* Convert the pass phrase from EBCDIC */
 372             ebcdic2ascii(buf, buf, klen);
 373 #endif
 374             kstr = (unsigned char *)buf;
 375         }
 376         /* Generate a salt */
 377         if (RAND_bytes(iv, EVP_CIPHER_get_iv_length(enc)) <= 0)
 378             goto err;
 379         /*
 380          * The 'iv' is used as the iv and as a salt.  It is NOT taken from
 381          * the BytesToKey function
 382          */
 383         if (!EVP_BytesToKey(enc, EVP_md5(), iv, kstr, klen, 1, key, NULL))
 384             goto err;
 385
 386         if (kstr == (unsigned char *)buf)
 387             OPENSSL_cleanse(buf, PEM_BUFSIZE);
 388
 389         buf[0] = '\0';
 390         PEM_proc_type(buf, PEM_TYPE_ENCRYPTED);
 391         PEM_dek_info(buf, objstr, EVP_CIPHER_get_iv_length(enc), (char *)iv);
 392         /* k=strlen(buf); */
 393
 394         ret = 1;
 395         if ((ctx = EVP_CIPHER_CTX_new()) == NULL
 396             || !EVP_EncryptInit_ex(ctx, enc, NULL, key, iv)
 397             || !EVP_EncryptUpdate(ctx, data, &j, data, i)
 398             || !EVP_EncryptFinal_ex(ctx, &(data[j]), &i))
 399             ret = 0;
 400         if (ret == 0)
 401             goto err;
 402         i += j;
 403     } else {
 404         ret = 1;
 405         buf[0] = '\0';
 406     }
 407     i = PEM_write_bio(bp, name, buf, data, i);
 408     if (i <= 0)
 409         ret = 0;
 410  err:
 411     OPENSSL_cleanse(key, sizeof(key));
 412     OPENSSL_cleanse(iv, sizeof(iv));
 413     EVP_CIPHER_CTX_free(ctx);
 414     OPENSSL_cleanse(buf, PEM_BUFSIZE);
 415     OPENSSL_clear_free(data, (unsigned int)dsize);
 416     return ret;
 417 }
 418
 419 int PEM_do_header(EVP_CIPHER_INFO *cipher, unsigned char *data, long *plen,
 420                   pem_password_cb *callback, void *u)
 421 {
 422     int ok;
 423     int keylen;
 424     long len = *plen;
 425     int ilen = (int) len;       /* EVP_DecryptUpdate etc. take int lengths */
 426     EVP_CIPHER_CTX *ctx;
 427     unsigned char key[EVP_MAX_KEY_LENGTH];
 428     char buf[PEM_BUFSIZE];
 429
 430 #if LONG_MAX > INT_MAX
 431     /* Check that we did not truncate the length */
 432     if (len > INT_MAX) {
 433         ERR_raise(ERR_LIB_PEM, PEM_R_HEADER_TOO_LONG);
 434         return 0;
 435     }
 436 #endif
 437
 438     if (cipher->cipher == NULL)
 439         return 1;
 440     if (callback == NULL)
 441         keylen = PEM_def_callback(buf, PEM_BUFSIZE, 0, u);
 442     else
 443         keylen = callback(buf, PEM_BUFSIZE, 0, u);
 444     if (keylen < 0) {
 445         ERR_raise(ERR_LIB_PEM, PEM_R_BAD_PASSWORD_READ);
 446         return 0;
 447     }
 448 #ifdef CHARSET_EBCDIC
 449     /* Convert the pass phrase from EBCDIC */
 450     ebcdic2ascii(buf, buf, keylen);
 451 #endif
 452
 453     if (!EVP_BytesToKey(cipher->cipher, EVP_md5(), &(cipher->iv[0]),
 454                         (unsigned char *)buf, keylen, 1, key, NULL))
 455         return 0;
 456
 457     ctx = EVP_CIPHER_CTX_new();
 458     if (ctx == NULL)
 459         return 0;
 460
 461     ok = EVP_DecryptInit_ex(ctx, cipher->cipher, NULL, key, &(cipher->iv[0]));
 462     if (ok)
 463         ok = EVP_DecryptUpdate(ctx, data, &ilen, data, ilen);
 464     if (ok) {
 465         /* Squirrel away the length of data decrypted so far. */
 466         *plen = ilen;
 467         ok = EVP_DecryptFinal_ex(ctx, &(data[ilen]), &ilen);
 468     }
 469     if (ok)
 470         *plen += ilen;
 471     else
 472         ERR_raise(ERR_LIB_PEM, PEM_R_BAD_DECRYPT);
 473
 474     EVP_CIPHER_CTX_free(ctx);
 475     OPENSSL_cleanse((char *)buf, sizeof(buf));
 476     OPENSSL_cleanse((char *)key, sizeof(key));
 477     return ok;
 478 }
 479
 480 /*
 481  * This implements a very limited PEM header parser that does not support the
 482  * full grammar of rfc1421.  In particular, folded headers are not supported,
 483  * nor is additional whitespace.
 484  *
 485  * A robust implementation would make use of a library that turns the headers
 486  * into a BIO from which one folded line is read at a time, and is then split
 487  * into a header label and content.  We would then parse the content of the
 488  * headers we care about.  This is overkill for just this limited use-case, but
 489  * presumably we also parse rfc822-style headers for S/MIME, so a common
 490  * abstraction might well be more generally useful.
 491  */
 492 #define PROC_TYPE "Proc-Type:"
 493 #define ENCRYPTED "ENCRYPTED"
 494 #define DEK_INFO "DEK-Info:"
 495 int PEM_get_EVP_CIPHER_INFO(char *header, EVP_CIPHER_INFO *cipher)
 496 {
 497     const EVP_CIPHER *enc = NULL;
 498     int ivlen;
 499     char *dekinfostart, c;
 500
 501     cipher->cipher = NULL;
 502     memset(cipher->iv, 0, sizeof(cipher->iv));
 503     if ((header == NULL) || (*header == '\0') || (*header == '\n'))
 504         return 1;
 505
 506     if (!CHECK_AND_SKIP_PREFIX(header, PROC_TYPE)) {
 507         ERR_raise(ERR_LIB_PEM, PEM_R_NOT_PROC_TYPE);
 508         return 0;
 509     }
 510     header += strspn(header, " \t");
 511
 512     if (*header++ != '4' || *header++ != ',')
 513         return 0;
 514     header += strspn(header, " \t");
 515
 516     /* We expect "ENCRYPTED" followed by optional white-space + line break */
 517     if (!CHECK_AND_SKIP_PREFIX(header, ENCRYPTED) ||
 518         strspn(header, " \t\r\n") == 0) {
 519         ERR_raise(ERR_LIB_PEM, PEM_R_NOT_ENCRYPTED);
 520         return 0;
 521     }
 522     header += strspn(header, " \t\r");
 523     if (*header++ != '\n') {
 524         ERR_raise(ERR_LIB_PEM, PEM_R_SHORT_HEADER);
 525         return 0;
 526     }
 527
 528     /*-
 529      * https://tools.ietf.org/html/rfc1421#section-4.6.1.3
 530      * We expect "DEK-Info: algo[,hex-parameters]"
 531      */
 532     if (!CHECK_AND_SKIP_PREFIX(header, DEK_INFO)) {
 533         ERR_raise(ERR_LIB_PEM, PEM_R_NOT_DEK_INFO);
 534         return 0;
 535     }
 536     header += strspn(header, " \t");
 537
 538     /*
 539      * DEK-INFO is a comma-separated combination of algorithm name and optional
 540      * parameters.
 541      */
 542     dekinfostart = header;
 543     header += strcspn(header, " \t,");
 544     c = *header;
 545     *header = '\0';
 546     cipher->cipher = enc = EVP_get_cipherbyname(dekinfostart);
 547     *header = c;
 548     header += strspn(header, " \t");
 549
 550     if (enc == NULL) {
 551         ERR_raise(ERR_LIB_PEM, PEM_R_UNSUPPORTED_ENCRYPTION);
 552         return 0;
 553     }
 554     ivlen = EVP_CIPHER_get_iv_length(enc);
 555     if (ivlen > 0 && *header++ != ',') {
 556         ERR_raise(ERR_LIB_PEM, PEM_R_MISSING_DEK_IV);
 557         return 0;
 558     } else if (ivlen == 0 && *header == ',') {
 559         ERR_raise(ERR_LIB_PEM, PEM_R_UNEXPECTED_DEK_IV);
 560         return 0;
 561     }
 562
 563     if (!load_iv(&header, cipher->iv, EVP_CIPHER_get_iv_length(enc)))
 564         return 0;
 565
 566     return 1;
 567 }
 568
 569 static int load_iv(char **fromp, unsigned char *to, int num)
 570 {
 571     int v, i;
 572     char *from;
 573
 574     from = *fromp;
 575     for (i = 0; i < num; i++)
 576         to[i] = 0;
 577     num *= 2;
 578     for (i = 0; i < num; i++) {
 579         v = OPENSSL_hexchar2int(*from);
 580         if (v < 0) {
 581             ERR_raise(ERR_LIB_PEM, PEM_R_BAD_IV_CHARS);
 582             return 0;
 583         }
 584         from++;
 585         to[i / 2] |= v << (long)((!(i & 1)) * 4);
 586     }
 587
 588     *fromp = from;
 589     return 1;
 590 }
 591
 592 #ifndef OPENSSL_NO_STDIO
 593 int PEM_write(FILE *fp, const char *name, const char *header,
 594               const unsigned char *data, long len)
 595 {
 596     BIO *b;
 597     int ret;
 598
 599     if ((b = BIO_new(BIO_s_file())) == NULL) {
 600         ERR_raise(ERR_LIB_PEM, ERR_R_BUF_LIB);
 601         return 0;
 602     }
 603     BIO_set_fp(b, fp, BIO_NOCLOSE);
 604     ret = PEM_write_bio(b, name, header, data, len);
 605     BIO_free(b);
 606     return ret;
 607 }
 608 #endif
 609
 610 int PEM_write_bio(BIO *bp, const char *name, const char *header,
 611                   const unsigned char *data, long len)
 612 {
 613     int nlen, n, i, j, outl;
 614     unsigned char *buf = NULL;
 615     EVP_ENCODE_CTX *ctx = EVP_ENCODE_CTX_new();
 616     int reason = 0;
 617     int retval = 0;
 618
 619     if (ctx == NULL) {
 620         reason = ERR_R_EVP_LIB;
 621         goto err;
 622     }
 623
 624     EVP_EncodeInit(ctx);
 625     nlen = strlen(name);
 626
 627     if ((BIO_write(bp, "-----BEGIN ", 11) != 11) ||
 628         (BIO_write(bp, name, nlen) != nlen) ||
 629         (BIO_write(bp, "-----\n", 6) != 6)) {
 630         reason = ERR_R_BIO_LIB;
 631         goto err;
 632     }
 633
 634     i = header != NULL ? strlen(header) : 0;
 635     if (i > 0) {
 636         if ((BIO_write(bp, header, i) != i) || (BIO_write(bp, "\n", 1) != 1)) {
 637             reason = ERR_R_BIO_LIB;
 638             goto err;
 639         }
 640     }
 641
 642     buf = OPENSSL_malloc(PEM_BUFSIZE * 8);
 643     if (buf == NULL)
 644         goto err;
 645
 646     i = j = 0;
 647     while (len > 0) {
 648         n = (int)((len > (PEM_BUFSIZE * 5)) ? (PEM_BUFSIZE * 5) : len);
 649         if (!EVP_EncodeUpdate(ctx, buf, &outl, &(data[j]), n)) {
 650             reason = ERR_R_EVP_LIB;
 651             goto err;
 652         }
 653         if ((outl) && (BIO_write(bp, (char *)buf, outl) != outl)) {
 654             reason = ERR_R_BIO_LIB;
 655             goto err;
 656         }
 657         i += outl;
 658         len -= n;
 659         j += n;
 660     }
 661     EVP_EncodeFinal(ctx, buf, &outl);
 662     if ((outl > 0) && (BIO_write(bp, (char *)buf, outl) != outl)) {
 663         reason = ERR_R_BIO_LIB;
 664         goto err;
 665     }
 666     if ((BIO_write(bp, "-----END ", 9) != 9) ||
 667         (BIO_write(bp, name, nlen) != nlen) ||
 668         (BIO_write(bp, "-----\n", 6) != 6)) {
 669         reason = ERR_R_BIO_LIB;
 670         goto err;
 671     }
 672     retval = i + outl;
 673
 674  err:
 675     if (retval == 0 && reason != 0)
 676         ERR_raise(ERR_LIB_PEM, reason);
 677     EVP_ENCODE_CTX_free(ctx);
 678     OPENSSL_clear_free(buf, PEM_BUFSIZE * 8);
 679     return retval;
 680 }
 681
 682 #ifndef OPENSSL_NO_STDIO
 683 int PEM_read(FILE *fp, char **name, char **header, unsigned char **data,
 684              long *len)
 685 {
 686     BIO *b;
 687     int ret;
 688
 689     if ((b = BIO_new(BIO_s_file())) == NULL) {
 690         ERR_raise(ERR_LIB_PEM, ERR_R_BUF_LIB);
 691         return 0;
 692     }
 693     BIO_set_fp(b, fp, BIO_NOCLOSE);
 694     ret = PEM_read_bio(b, name, header, data, len);
 695     BIO_free(b);
 696     return ret;
 697 }
 698 #endif
 699
 700 /* Some helpers for PEM_read_bio_ex(). */
 701 static int sanitize_line(char *linebuf, int len, unsigned int flags, int first_call)
 702 {
 703     int i;
 704     if (first_call) {
 705         /* Other BOMs imply unsupported multibyte encoding,
 706          * so don't strip them and let the error raise */
 707         const unsigned char utf8_bom[3] = {0xEF, 0xBB, 0xBF};
 708
 709         if (len > 3 && memcmp(linebuf, utf8_bom, 3) == 0) {
 710             memmove(linebuf, linebuf + 3, len - 3);
 711             linebuf[len - 3] = 0;
 712             len -= 3;
 713         }
 714     }
 715
 716     if (flags & PEM_FLAG_EAY_COMPATIBLE) {
 717         /* Strip trailing whitespace */
 718         while ((len >= 0) && (linebuf[len] <= ' '))
 719             len--;
 720         /* Go back to whitespace before applying uniform line ending. */
 721         len++;
 722     } else if (flags & PEM_FLAG_ONLY_B64) {
 723         for (i = 0; i < len; ++i) {
 724             if (!ossl_isbase64(linebuf[i]) || linebuf[i] == '\n'
 725                 || linebuf[i] == '\r')
 726                 break;
 727         }
 728         len = i;
 729     } else {
 730         /* EVP_DecodeBlock strips leading and trailing whitespace, so just strip
 731          * control characters in-place and let everything through. */
 732         for (i = 0; i < len; ++i) {
 733             if (linebuf[i] == '\n' || linebuf[i] == '\r')
 734                 break;
 735             if (ossl_iscntrl(linebuf[i]))
 736                 linebuf[i] = ' ';
 737         }
 738         len = i;
 739     }
 740     /* The caller allocated LINESIZE+1, so this is safe. */
 741     linebuf[len++] = '\n';
 742     linebuf[len] = '\0';
 743     return len;
 744 }
 745
 746 #define LINESIZE 255
 747 /* Note trailing spaces for begin and end. */
 748 #define BEGINSTR "-----BEGIN "
 749 #define ENDSTR "-----END "
 750 #define TAILSTR "-----\n"
 751 #define BEGINLEN ((int)(sizeof(BEGINSTR) - 1))
 752 #define ENDLEN ((int)(sizeof(ENDSTR) - 1))
 753 #define TAILLEN ((int)(sizeof(TAILSTR) - 1))
 754 static int get_name(BIO *bp, char **name, unsigned int flags)
 755 {
 756     char *linebuf;
 757     int ret = 0;
 758     int len;
 759     int first_call = 1;
 760
 761     /*
 762      * Need to hold trailing NUL (accounted for by BIO_gets() and the newline
 763      * that will be added by sanitize_line() (the extra '1').
 764      */
 765     linebuf = PEM_MALLOC(LINESIZE + 1, flags);
 766     if (linebuf == NULL)
 767         return 0;
 768
 769     do {
 770         len = BIO_gets(bp, linebuf, LINESIZE);
 771
 772         if (len <= 0) {
 773             ERR_raise(ERR_LIB_PEM, PEM_R_NO_START_LINE);
 774             goto err;
 775         }
 776
 777         /* Strip trailing garbage and standardize ending. */
 778         len = sanitize_line(linebuf, len, flags & ~PEM_FLAG_ONLY_B64, first_call);
 779         first_call = 0;
 780
 781         /* Allow leading empty or non-matching lines. */
 782     } while (!HAS_PREFIX(linebuf, BEGINSTR)
 783              || len < TAILLEN
 784              || !HAS_PREFIX(linebuf + len - TAILLEN, TAILSTR));
 785     linebuf[len - TAILLEN] = '\0';
 786     len = len - BEGINLEN - TAILLEN + 1;
 787     *name = PEM_MALLOC(len, flags);
 788     if (*name == NULL)
 789         goto err;
 790     memcpy(*name, linebuf + BEGINLEN, len);
 791     ret = 1;
 792
 793 err:
 794     PEM_FREE(linebuf, flags, LINESIZE + 1);
 795     return ret;
 796 }
 797
 798 /* Keep track of how much of a header we've seen. */
 799 enum header_status {
 800     MAYBE_HEADER,
 801     IN_HEADER,
 802     POST_HEADER
 803 };
 804
 805 /**
 806  * Extract the optional PEM header, with details on the type of content and
 807  * any encryption used on the contents, and the bulk of the data from the bio.
 808  * The end of the header is marked by a blank line; if the end-of-input marker
 809  * is reached prior to a blank line, there is no header.
 810  *
 811  * The header and data arguments are BIO** since we may have to swap them
 812  * if there is no header, for efficiency.
 813  *
 814  * We need the name of the PEM-encoded type to verify the end string.
 815  */
 816 static int get_header_and_data(BIO *bp, BIO **header, BIO **data, char *name,
 817                                unsigned int flags)
 818 {
 819     BIO *tmp = *header;
 820     char *linebuf, *p;
 821     int len, ret = 0, end = 0, prev_partial_line_read = 0, partial_line_read = 0;
 822     /* 0 if not seen (yet), 1 if reading header, 2 if finished header */
 823     enum header_status got_header = MAYBE_HEADER;
 824     unsigned int flags_mask;
 825     size_t namelen;
 826
 827     /* Need to hold trailing NUL (accounted for by BIO_gets() and the newline
 828      * that will be added by sanitize_line() (the extra '1'). */
 829     linebuf = PEM_MALLOC(LINESIZE + 1, flags);
 830     if (linebuf == NULL)
 831         return 0;
 832
 833     while(1) {
 834         flags_mask = ~0u;
 835         len = BIO_gets(bp, linebuf, LINESIZE);
 836         if (len <= 0) {
 837             ERR_raise(ERR_LIB_PEM, PEM_R_BAD_END_LINE);
 838             goto err;
 839         }
 840
 841         /*
 842          * Check if line has been read completely or if only part of the line
 843          * has been read. Keep the previous value to ignore newlines that
 844          * appear due to reading a line up until the char before the newline.
 845          */
 846         prev_partial_line_read = partial_line_read;
 847         partial_line_read = len == LINESIZE-1 && linebuf[LINESIZE-2] != '\n';
 848
 849         if (got_header == MAYBE_HEADER) {
 850             if (memchr(linebuf, ':', len) != NULL)
 851                 got_header = IN_HEADER;
 852         }
 853         if (HAS_PREFIX(linebuf, ENDSTR) || got_header == IN_HEADER)
 854             flags_mask &= ~PEM_FLAG_ONLY_B64;
 855         len = sanitize_line(linebuf, len, flags & flags_mask, 0);
 856
 857         /* Check for end of header. */
 858         if (linebuf[0] == '\n') {
 859             /*
 860              * If previous line has been read only partially this newline is a
 861              * regular newline at the end of a line and not an empty line.
 862              */
 863             if (!prev_partial_line_read) {
 864                 if (got_header == POST_HEADER) {
 865                     /* Another blank line is an error. */
 866                     ERR_raise(ERR_LIB_PEM, PEM_R_BAD_END_LINE);
 867                     goto err;
 868                 }
 869                 got_header = POST_HEADER;
 870                 tmp = *data;
 871             }
 872             continue;
 873         }
 874
 875         /* Check for end of stream (which means there is no header). */
 876         p = linebuf;
 877         if (CHECK_AND_SKIP_PREFIX(p, ENDSTR)) {
 878             namelen = strlen(name);
 879             if (strncmp(p, name, namelen) != 0 ||
 880                 !HAS_PREFIX(p + namelen, TAILSTR)) {
 881                 ERR_raise(ERR_LIB_PEM, PEM_R_BAD_END_LINE);
 882                 goto err;
 883             }
 884             if (got_header == MAYBE_HEADER) {
 885                 *header = *data;
 886                 *data = tmp;
 887             }
 888             break;
 889         } else if (end) {
 890             /* Malformed input; short line not at end of data. */
 891             ERR_raise(ERR_LIB_PEM, PEM_R_BAD_END_LINE);
 892             goto err;
 893         }
 894         /*
 895          * Else, a line of text -- could be header or data; we don't
 896          * know yet.  Just pass it through.
 897          */
 898         if (BIO_puts(tmp, linebuf) < 0)
 899             goto err;
 900         /*
 901          * Only encrypted files need the line length check applied.
 902          */
 903         if (got_header == POST_HEADER) {
 904             /* 65 includes the trailing newline */
 905             if (len > 65)
 906                 goto err;
 907             if (len < 65)
 908                 end = 1;
 909         }
 910     }
 911
 912     ret = 1;
 913 err:
 914     PEM_FREE(linebuf, flags, LINESIZE + 1);
 915     return ret;
 916 }
 917
 918 /**
 919  * Read in PEM-formatted data from the given BIO.
 920  *
 921  * By nature of the PEM format, all content must be printable ASCII (except
 922  * for line endings).  Other characters are malformed input and will be rejected.
 923  */
 924 int PEM_read_bio_ex(BIO *bp, char **name_out, char **header,
 925                     unsigned char **data, long *len_out, unsigned int flags)
 926 {
 927     EVP_ENCODE_CTX *ctx = NULL;
 928     const BIO_METHOD *bmeth;
 929     BIO *headerB = NULL, *dataB = NULL;
 930     char *name = NULL;
 931     int len, taillen, headerlen, ret = 0;
 932     BUF_MEM * buf_mem;
 933
 934     *len_out = 0;
 935     *name_out = *header = NULL;
 936     *data = NULL;
 937     if ((flags & PEM_FLAG_EAY_COMPATIBLE) && (flags & PEM_FLAG_ONLY_B64)) {
 938         /* These two are mutually incompatible; bail out. */
 939         ERR_raise(ERR_LIB_PEM, ERR_R_PASSED_INVALID_ARGUMENT);
 940         goto end;
 941     }
 942     bmeth = (flags & PEM_FLAG_SECURE) ? BIO_s_secmem() : BIO_s_mem();
 943
 944     headerB = BIO_new(bmeth);
 945     dataB = BIO_new(bmeth);
 946     if (headerB == NULL || dataB == NULL) {
 947         ERR_raise(ERR_LIB_PEM, ERR_R_BIO_LIB);
 948         goto end;
 949     }
 950
 951     if (!get_name(bp, &name, flags))
 952         goto end;
 953     if (!get_header_and_data(bp, &headerB, &dataB, name, flags))
 954         goto end;
 955
 956     BIO_get_mem_ptr(dataB, &buf_mem);
 957     len = buf_mem->length;
 958
 959     /* There was no data in the PEM file */
 960     if (len == 0)
 961         goto end;
 962
 963     ctx = EVP_ENCODE_CTX_new();
 964     if (ctx == NULL) {
 965         ERR_raise(ERR_LIB_PEM, ERR_R_EVP_LIB);
 966         goto end;
 967     }
 968
 969     EVP_DecodeInit(ctx);
 970     if (EVP_DecodeUpdate(ctx, (unsigned char*)buf_mem->data, &len,
 971                          (unsigned char*)buf_mem->data, len) < 0
 972             || EVP_DecodeFinal(ctx, (unsigned char*)&(buf_mem->data[len]),
 973                                &taillen) < 0) {
 974         ERR_raise(ERR_LIB_PEM, PEM_R_BAD_BASE64_DECODE);
 975         goto end;
 976     }
 977     len += taillen;
 978     buf_mem->length = len;
 979
 980     headerlen = BIO_get_mem_data(headerB, NULL);
 981     *header = PEM_MALLOC(headerlen + 1, flags);
 982     *data = PEM_MALLOC(len, flags);
 983     if (*header == NULL || *data == NULL)
 984         goto out_free;
 985     if (headerlen != 0 && BIO_read(headerB, *header, headerlen) != headerlen)
 986         goto out_free;
 987     (*header)[headerlen] = '\0';
 988     if (BIO_read(dataB, *data, len) != len)
 989         goto out_free;
 990     *len_out = len;
 991     *name_out = name;
 992     name = NULL;
 993     ret = 1;
 994     goto end;
 995
 996 out_free:
 997     PEM_FREE(*header, flags, 0);
 998     *header = NULL;
 999     PEM_FREE(*data, flags, 0);
1000     *data = NULL;
1001 end:
1002     EVP_ENCODE_CTX_free(ctx);
1003     PEM_FREE(name, flags, 0);
1004     BIO_free(headerB);
1005     BIO_free(dataB);
1006     return ret;
1007 }
1008
1009 int PEM_read_bio(BIO *bp, char **name, char **header, unsigned char **data,
1010                  long *len)
1011 {
1012     return PEM_read_bio_ex(bp, name, header, data, len, PEM_FLAG_EAY_COMPATIBLE);
1013 }
1014
1015 /*
1016  * Check pem string and return prefix length. If for example the pem_str ==
1017  * "RSA PRIVATE KEY" and suffix = "PRIVATE KEY" the return value is 3 for the
1018  * string "RSA".
1019  */
1020
1021 int ossl_pem_check_suffix(const char *pem_str, const char *suffix)
1022 {
1023     int pem_len = strlen(pem_str);
1024     int suffix_len = strlen(suffix);
1025     const char *p;
1026     if (suffix_len + 1 >= pem_len)
1027         return 0;
1028     p = pem_str + pem_len - suffix_len;
1029     if (strcmp(p, suffix))
1030         return 0;
1031     p--;
1032     if (*p != ' ')
1033         return 0;
1034     return p - pem_str;
1035 }