/* $OpenBSD: p5_crpt2.c,v 1.24 2021/12/12 21:27:37 tb Exp $ */

/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL

 * project 1999.

 */

/* ====================================================================

 * Copyright (c) 1999-2006 The OpenSSL Project.  All rights reserved.

 *

 * 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 above 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 acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"

 *

 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    licensing@OpenSSL.org.

 *

 * 5. Products derived from this software may not be called "OpenSSL"

 *    nor may "OpenSSL" appear in their names without prior written

 *    permission of the OpenSSL Project.

 *

 * 6. Redistributions of any form whatsoever must retain the following

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"

 *

 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

 * EXPRESSED 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 OpenSSL PROJECT OR

 * ITS 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.

 * ====================================================================

 *

 * This product includes cryptographic software written by Eric Young

 * (eay@cryptsoft.com).  This product includes software written by Tim

 * Hudson (tjh@cryptsoft.com).

 *

 */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <openssl/opensslconf.h>

#if !defined(OPENSSL_NO_HMAC) && !defined(OPENSSL_NO_SHA)

#include <openssl/err.h>

#include <openssl/evp.h>

#include <openssl/hmac.h>

#include <openssl/x509.h>

#include "evp_locl.h"

#include "hmac_local.h"

/* This is an implementation of PKCS#5 v2.0 password based encryption key

 * derivation function PBKDF2.

 * SHA1 version verified against test vectors posted by Peter Gutmann

 * <pgut001@cs.auckland.ac.nz> to the PKCS-TNG <pkcs-tng@rsa.com> mailing list.

 */

int

PKCS5_PBKDF2_HMAC(const char *pass, int passlen, const unsigned char *salt,

    int saltlen, int iter, const EVP_MD *digest, int keylen, unsigned char *out)

{

  unsigned char digtmp[EVP_MAX_MD_SIZE], *p, itmp[4];

  int cplen, j, k, tkeylen, mdlen;

  unsigned long i = 1;

  HMAC_CTX hctx_tpl, hctx;

  mdlen = EVP_MD_size(digest);

  if (mdlen < 0)

    return 0;

  HMAC_CTX_init(&hctx_tpl);

  p = out;

  tkeylen = keylen;

  if (!pass)

    passlen = 0;

  else if (passlen == -1)

    passlen = strlen(pass);

  if (!HMAC_Init_ex(&hctx_tpl, pass, passlen, digest, NULL)) {

    HMAC_CTX_cleanup(&hctx_tpl);

    return 0;

  }

  while (tkeylen) {

    if (tkeylen > mdlen)

      cplen = mdlen;

    else

      cplen = tkeylen;

    /* We are unlikely to ever use more than 256 blocks (5120 bits!)

     * but just in case...

     */

    itmp[0] = (unsigned char)((i >> 24) & 0xff);

    itmp[1] = (unsigned char)((i >> 16) & 0xff);

    itmp[2] = (unsigned char)((i >> 8) & 0xff);

    itmp[3] = (unsigned char)(i & 0xff);

    if (!HMAC_CTX_copy(&hctx, &hctx_tpl)) {

      HMAC_CTX_cleanup(&hctx_tpl);

      return 0;

    }

    if (!HMAC_Update(&hctx, salt, saltlen) ||

        !HMAC_Update(&hctx, itmp, 4) ||

        !HMAC_Final(&hctx, digtmp, NULL)) {

      HMAC_CTX_cleanup(&hctx_tpl);

      HMAC_CTX_cleanup(&hctx);

      return 0;

    }

    HMAC_CTX_cleanup(&hctx);

    memcpy(p, digtmp, cplen);

    for (j = 1; j < iter; j++) {

      if (!HMAC_CTX_copy(&hctx, &hctx_tpl)) {

        HMAC_CTX_cleanup(&hctx_tpl);

        return 0;

      }

      if (!HMAC_Update(&hctx, digtmp, mdlen) ||

          !HMAC_Final(&hctx, digtmp, NULL)) {

        HMAC_CTX_cleanup(&hctx_tpl);

        HMAC_CTX_cleanup(&hctx);

        return 0;

      }

      HMAC_CTX_cleanup(&hctx);

      for (k = 0; k < cplen; k++)

        p[k] ^= digtmp[k];

    }

    tkeylen -= cplen;

    i++;

    p += cplen;

  }

  HMAC_CTX_cleanup(&hctx_tpl);

  return 1;

}

int

PKCS5_PBKDF2_HMAC_SHA1(const char *pass, int passlen, const unsigned char *salt,

    int saltlen, int iter, int keylen, unsigned char *out)

{

  return PKCS5_PBKDF2_HMAC(pass, passlen, salt, saltlen, iter,

      EVP_sha1(), keylen, out);

}

/* Now the key derivation function itself. This is a bit evil because

 * it has to check the ASN1 parameters are valid: and there are quite a

 * few of them...

 */

int

PKCS5_v2_PBE_keyivgen(EVP_CIPHER_CTX *ctx, const char *pass, int passlen,

    ASN1_TYPE *param, const EVP_CIPHER *c, const EVP_MD *md, int en_de)

{

  const unsigned char *pbuf;

  int plen;

  PBE2PARAM *pbe2 = NULL;

  const EVP_CIPHER *cipher;

  int rv = 0;

  if (param == NULL || param->type != V_ASN1_SEQUENCE ||

      param->value.sequence == NULL) {

    EVPerror(EVP_R_DECODE_ERROR);

    goto err;

  }

  pbuf = param->value.sequence->data;

  plen = param->value.sequence->length;

  if (!(pbe2 = d2i_PBE2PARAM(NULL, &pbuf, plen))) {

    EVPerror(EVP_R_DECODE_ERROR);

    goto err;

  }

  /* See if we recognise the key derivation function */

  if (OBJ_obj2nid(pbe2->keyfunc->algorithm) != NID_id_pbkdf2) {

    EVPerror(EVP_R_UNSUPPORTED_KEY_DERIVATION_FUNCTION);

    goto err;

  }

  /* lets see if we recognise the encryption algorithm.

   */

  cipher = EVP_get_cipherbyobj(pbe2->encryption->algorithm);

  if (!cipher) {

    EVPerror(EVP_R_UNSUPPORTED_CIPHER);

    goto err;

  }

  /* Fixup cipher based on AlgorithmIdentifier */

  if (!EVP_CipherInit_ex(ctx, cipher, NULL, NULL, NULL, en_de))

    goto err;

  if (EVP_CIPHER_asn1_to_param(ctx, pbe2->encryption->parameter) < 0) {

    EVPerror(EVP_R_CIPHER_PARAMETER_ERROR);

    goto err;

  }

  rv = PKCS5_v2_PBKDF2_keyivgen(ctx, pass, passlen,

      pbe2->keyfunc->parameter, c, md, en_de);

err:

  PBE2PARAM_free(pbe2);

  return rv;

}

int

PKCS5_v2_PBKDF2_keyivgen(EVP_CIPHER_CTX *ctx, const char *pass, int passlen,

    ASN1_TYPE *param, const EVP_CIPHER *c, const EVP_MD *md, int en_de)

{

  unsigned char *salt, key[EVP_MAX_KEY_LENGTH];

  const unsigned char *pbuf;

  int saltlen, iter, plen;

  int rv = 0;

  unsigned int keylen = 0;

  int prf_nid, hmac_md_nid;

  PBKDF2PARAM *kdf = NULL;

  const EVP_MD *prfmd;

  if (EVP_CIPHER_CTX_cipher(ctx) == NULL) {

    EVPerror(EVP_R_NO_CIPHER_SET);

    return 0;

  }

  keylen = EVP_CIPHER_CTX_key_length(ctx);

  if (keylen > sizeof key) {

    EVPerror(EVP_R_BAD_KEY_LENGTH);

    return 0;

  }

  /* Decode parameter */

  if (!param || (param->type != V_ASN1_SEQUENCE)) {

    EVPerror(EVP_R_DECODE_ERROR);

    return 0;

  }

  pbuf = param->value.sequence->data;

  plen = param->value.sequence->length;

  if (!(kdf = d2i_PBKDF2PARAM(NULL, &pbuf, plen)) ) {

    EVPerror(EVP_R_DECODE_ERROR);

    return 0;

  }

  /* Now check the parameters of the kdf */

  if (kdf->keylength &&

      (ASN1_INTEGER_get(kdf->keylength) != (int)keylen)){

    EVPerror(EVP_R_UNSUPPORTED_KEYLENGTH);

    goto err;

  }

  if (kdf->prf)

    prf_nid = OBJ_obj2nid(kdf->prf->algorithm);

  else

    prf_nid = NID_hmacWithSHA1;

  if (!EVP_PBE_find(EVP_PBE_TYPE_PRF, prf_nid, NULL, &hmac_md_nid, 0)) {

    EVPerror(EVP_R_UNSUPPORTED_PRF);

    goto err;

  }

  prfmd = EVP_get_digestbynid(hmac_md_nid);

  if (prfmd == NULL) {

    EVPerror(EVP_R_UNSUPPORTED_PRF);

    goto err;

  }

  if (kdf->salt->type != V_ASN1_OCTET_STRING) {

    EVPerror(EVP_R_UNSUPPORTED_SALT_TYPE);

    goto err;

  }

  /* it seems that its all OK */

  salt = kdf->salt->value.octet_string->data;

  saltlen = kdf->salt->value.octet_string->length;

  if ((iter = ASN1_INTEGER_get(kdf->iter)) <= 0) {

    EVPerror(EVP_R_UNSUPORTED_NUMBER_OF_ROUNDS);

    goto err;

  }

  if (!PKCS5_PBKDF2_HMAC(pass, passlen, salt, saltlen, iter, prfmd,

      keylen, key))

    goto err;

  rv = EVP_CipherInit_ex(ctx, NULL, NULL, key, NULL, en_de);

err:

  explicit_bzero(key, keylen);

  PBKDF2PARAM_free(kdf);

  return rv;

}

#endif