/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)

 * All rights reserved.

 *

 * This package is an SSL implementation written

 * by Eric Young (eay@cryptsoft.com).

 * The implementation was written so as to conform with Netscapes SSL.

 *

 * This library is free for commercial and non-commercial use as long as

 * the following conditions are aheared to.  The following conditions

 * apply to all code found in this distribution, be it the RC4, RSA,

 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation

 * included with this distribution is covered by the same copyright terms

 * except that the holder is Tim Hudson (tjh@cryptsoft.com).

 *

 * Copyright remains Eric Young's, and as such any Copyright notices in

 * the code are not to be removed.

 * If this package is used in a product, Eric Young should be given attribution

 * as the author of the parts of the library used.

 * This can be in the form of a textual message at program startup or

 * in documentation (online or textual) provided with the package.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. All advertising materials mentioning features or use of this software

 *    must display the following acknowledgement:

 *    "This product includes cryptographic software written by

 *     Eric Young (eay@cryptsoft.com)"

 *    The word 'cryptographic' can be left out if the rouines from the library

 *    being used are not cryptographic related :-).

 * 4. If you include any Windows specific code (or a derivative thereof) from

 *    the apps directory (application code) you must include an acknowledgement:

 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"

 *

 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 *

 * The licence and distribution terms for any publically available version or

 * derivative of this code cannot be changed.  i.e. this code cannot simply be

 * copied and put under another distribution licence

 * [including the GNU Public Licence.]

 */

#include <openssl/pem.h>

#include <assert.h>

#include <stdio.h>

#include <string.h>

#include <openssl/dsa.h>

#include <openssl/err.h>

#include <openssl/evp.h>

#include <openssl/mem.h>

#include <openssl/obj.h>

#include <openssl/rsa.h>

#include <openssl/x509.h>

STACK_OF(X509_INFO) *PEM_X509_INFO_read(FILE *fp, STACK_OF(X509_INFO) *sk,

                                        pem_password_cb *cb, void *u) {

  BIO *b = BIO_new_fp(fp, BIO_NOCLOSE);

  if (b == NULL) {

    OPENSSL_PUT_ERROR(PEM, ERR_R_BUF_LIB);

    return 0;

  }

  STACK_OF(X509_INFO) *ret = PEM_X509_INFO_read_bio(b, sk, cb, u);

  BIO_free(b);

  return ret;

}

enum parse_result_t {

  parse_ok,

  parse_error,

  parse_new_entry,

};

static enum parse_result_t parse_x509(X509_INFO *info, const uint8_t *data,

                                      size_t len, int key_type) {

  if (info->x509 != NULL) {

    return parse_new_entry;

  }

  info->x509 = d2i_X509(NULL, &data, len);

  return info->x509 != NULL ? parse_ok : parse_error;

}

static enum parse_result_t parse_x509_aux(X509_INFO *info, const uint8_t *data,

                                          size_t len, int key_type) {

  if (info->x509 != NULL) {

    return parse_new_entry;

  }

  info->x509 = d2i_X509_AUX(NULL, &data, len);

  return info->x509 != NULL ? parse_ok : parse_error;

}

static enum parse_result_t parse_crl(X509_INFO *info, const uint8_t *data,

                                     size_t len, int key_type) {

  if (info->crl != NULL) {

    return parse_new_entry;

  }

  info->crl = d2i_X509_CRL(NULL, &data, len);

  return info->crl != NULL ? parse_ok : parse_error;

}

static enum parse_result_t parse_key(X509_INFO *info, const uint8_t *data,

                                     size_t len, int key_type) {

  if (info->x_pkey != NULL) {

    return parse_new_entry;

  }

  info->x_pkey = X509_PKEY_new();

  if (info->x_pkey == NULL) {

    return parse_error;

  }

  info->x_pkey->dec_pkey = d2i_PrivateKey(key_type, NULL, &data, len);

  return info->x_pkey->dec_pkey != NULL ? parse_ok : parse_error;

}

STACK_OF(X509_INFO) *PEM_X509_INFO_read_bio(BIO *bp, STACK_OF(X509_INFO) *sk,

                                            pem_password_cb *cb, void *u) {

  X509_INFO *info = NULL;

  char *name = NULL, *header = NULL;

  unsigned char *data = NULL;

  long len;

  int ok = 0;

  STACK_OF(X509_INFO) *ret = NULL;

  if (sk == NULL) {

    ret = sk_X509_INFO_new_null();

    if (ret == NULL) {

      return NULL;

    }

  } else {

    ret = sk;

  }

  size_t orig_num = sk_X509_INFO_num(ret);

  info = X509_INFO_new();

  if (info == NULL) {

    goto err;

  }

  for (;;) {

    if (!PEM_read_bio(bp, &name, &header, &data, &len)) {

      uint32_t error = ERR_peek_last_error();

      if (ERR_GET_LIB(error) == ERR_LIB_PEM &&

          ERR_GET_REASON(error) == PEM_R_NO_START_LINE) {

        ERR_clear_error();

        break;

      }

      goto err;

    }

    enum parse_result_t (*parse_function)(X509_INFO *, const uint8_t *, size_t,

                                          int) = NULL;

    int key_type = EVP_PKEY_NONE;

    if (strcmp(name, PEM_STRING_X509) == 0 ||

        strcmp(name, PEM_STRING_X509_OLD) == 0) {

      parse_function = parse_x509;

    } else if (strcmp(name, PEM_STRING_X509_TRUSTED) == 0) {

      parse_function = parse_x509_aux;

    } else if (strcmp(name, PEM_STRING_X509_CRL) == 0) {

      parse_function = parse_crl;

    } else if (strcmp(name, PEM_STRING_RSA) == 0) {

      parse_function = parse_key;

      key_type = EVP_PKEY_RSA;

    } else if (strcmp(name, PEM_STRING_DSA) == 0) {

      parse_function = parse_key;

      key_type = EVP_PKEY_DSA;

    } else if (strcmp(name, PEM_STRING_ECPRIVATEKEY) == 0) {

      parse_function = parse_key;

      key_type = EVP_PKEY_EC;

    }

    // If a private key has a header, assume it is encrypted.

    if (key_type != EVP_PKEY_NONE && strlen(header) > 10) {

      if (info->x_pkey != NULL) {

        if (!sk_X509_INFO_push(ret, info)) {

          goto err;

        }

        info = X509_INFO_new();

        if (info == NULL) {

          goto err;

        }

      }

      // Historically, raw entries pushed an empty key.

      info->x_pkey = X509_PKEY_new();

      if (info->x_pkey == NULL ||

          !PEM_get_EVP_CIPHER_INFO(header, &info->enc_cipher)) {

        goto err;

      }

      info->enc_data = (char *)data;

      info->enc_len = (int)len;

      data = NULL;

    } else if (parse_function != NULL) {

      EVP_CIPHER_INFO cipher;

      if (!PEM_get_EVP_CIPHER_INFO(header, &cipher) ||

          !PEM_do_header(&cipher, data, &len, cb, u)) {

        goto err;

      }

      enum parse_result_t result = parse_function(info, data, len, key_type);

      if (result == parse_new_entry) {

        if (!sk_X509_INFO_push(ret, info)) {

          goto err;

        }

        info = X509_INFO_new();

        if (info == NULL) {

          goto err;

        }

        result = parse_function(info, data, len, key_type);

      }

      if (result != parse_ok) {

        OPENSSL_PUT_ERROR(PEM, ERR_R_ASN1_LIB);

        goto err;

      }

    }

    OPENSSL_free(name);

    OPENSSL_free(header);

    OPENSSL_free(data);

    name = NULL;

    header = NULL;

    data = NULL;

  }

  // Push the last entry on the stack if not empty.

  if (info->x509 != NULL || info->crl != NULL || info->x_pkey != NULL ||

      info->enc_data != NULL) {

    if (!sk_X509_INFO_push(ret, info)) {

      goto err;

    }

    info = NULL;

  }

  ok = 1;

err:

  X509_INFO_free(info);

  if (!ok) {

    while (sk_X509_INFO_num(ret) > orig_num) {

      X509_INFO_free(sk_X509_INFO_pop(ret));

    }

    if (ret != sk) {

      sk_X509_INFO_free(ret);

    }

    ret = NULL;

  }

  OPENSSL_free(name);

  OPENSSL_free(header);

  OPENSSL_free(data);

  return ret;

}