/*

 * Copyright 1999-2018 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#include <stdio.h>

#include "internal/cryptlib.h"

#include <openssl/asn1t.h>

#include <openssl/x509.h>

#include <openssl/rand.h>

/* PKCS#5 v2.0 password based encryption structures */

ASN1_SEQUENCE(PBE2PARAM) = {

        ASN1_SIMPLE(PBE2PARAM, keyfunc, X509_ALGOR),

        ASN1_SIMPLE(PBE2PARAM, encryption, X509_ALGOR)

} ASN1_SEQUENCE_END(PBE2PARAM)

IMPLEMENT_ASN1_FUNCTIONS(PBE2PARAM)

ASN1_SEQUENCE(PBKDF2PARAM) = {

        ASN1_SIMPLE(PBKDF2PARAM, salt, ASN1_ANY),

        ASN1_SIMPLE(PBKDF2PARAM, iter, ASN1_INTEGER),

        ASN1_OPT(PBKDF2PARAM, keylength, ASN1_INTEGER),

        ASN1_OPT(PBKDF2PARAM, prf, X509_ALGOR)

} ASN1_SEQUENCE_END(PBKDF2PARAM)

IMPLEMENT_ASN1_FUNCTIONS(PBKDF2PARAM)

/*

 * Return an algorithm identifier for a PKCS#5 v2.0 PBE algorithm: yes I know

 * this is horrible! Extended version to allow application supplied PRF NID

 * and IV.

 */

X509_ALGOR *PKCS5_pbe2_set_iv(const EVP_CIPHER *cipher, int iter,

                              unsigned char *salt, int saltlen,

                              unsigned char *aiv, int prf_nid)

{

    X509_ALGOR *scheme = NULL, *ret = NULL;

    int alg_nid, keylen;

    EVP_CIPHER_CTX *ctx = NULL;

    unsigned char iv[EVP_MAX_IV_LENGTH];

    PBE2PARAM *pbe2 = NULL;

    alg_nid = EVP_CIPHER_type(cipher);

    if (alg_nid == NID_undef) {

        ASN1err(ASN1_F_PKCS5_PBE2_SET_IV,

                ASN1_R_CIPHER_HAS_NO_OBJECT_IDENTIFIER);

        goto err;

    }

    if ((pbe2 = PBE2PARAM_new()) == NULL)

        goto merr;

    /* Setup the AlgorithmIdentifier for the encryption scheme */

    scheme = pbe2->encryption;

    scheme->algorithm = OBJ_nid2obj(alg_nid);

    if ((scheme->parameter = ASN1_TYPE_new()) == NULL)

        goto merr;

    /* Create random IV */

    if (EVP_CIPHER_iv_length(cipher)) {

        if (aiv)

            memcpy(iv, aiv, EVP_CIPHER_iv_length(cipher));

        else if (RAND_bytes(iv, EVP_CIPHER_iv_length(cipher)) <= 0)

            goto err;

    }

    ctx = EVP_CIPHER_CTX_new();

    if (ctx == NULL)

        goto merr;

    /* Dummy cipherinit to just setup the IV, and PRF */

    if (!EVP_CipherInit_ex(ctx, cipher, NULL, NULL, iv, 0))

        goto err;

    if (EVP_CIPHER_param_to_asn1(ctx, scheme->parameter) <= 0) {

        ASN1err(ASN1_F_PKCS5_PBE2_SET_IV, ASN1_R_ERROR_SETTING_CIPHER_PARAMS);

        goto err;

    }

    /*

     * If prf NID unspecified see if cipher has a preference. An error is OK

     * here: just means use default PRF.

     */

    if ((prf_nid == -1) &&

        EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_PBE_PRF_NID, 0, &prf_nid) <= 0) {

        ERR_clear_error();

        prf_nid = NID_hmacWithSHA256;

    }

    EVP_CIPHER_CTX_free(ctx);

    ctx = NULL;

    /* If its RC2 then we'd better setup the key length */

    if (alg_nid == NID_rc2_cbc)

        keylen = EVP_CIPHER_key_length(cipher);

    else

        keylen = -1;

    /* Setup keyfunc */

    X509_ALGOR_free(pbe2->keyfunc);

    pbe2->keyfunc = PKCS5_pbkdf2_set(iter, salt, saltlen, prf_nid, keylen);

    if (!pbe2->keyfunc)

        goto merr;

    /* Now set up top level AlgorithmIdentifier */

    if ((ret = X509_ALGOR_new()) == NULL)

        goto merr;

    ret->algorithm = OBJ_nid2obj(NID_pbes2);

    /* Encode PBE2PARAM into parameter */

    if (!ASN1_TYPE_pack_sequence(ASN1_ITEM_rptr(PBE2PARAM), pbe2,

                                 &ret->parameter))

         goto merr;

    PBE2PARAM_free(pbe2);

    pbe2 = NULL;

    return ret;

 merr:

    ASN1err(ASN1_F_PKCS5_PBE2_SET_IV, ERR_R_MALLOC_FAILURE);

 err:

    EVP_CIPHER_CTX_free(ctx);

    PBE2PARAM_free(pbe2);

    /* Note 'scheme' is freed as part of pbe2 */

    X509_ALGOR_free(ret);

    return NULL;

}

X509_ALGOR *PKCS5_pbe2_set(const EVP_CIPHER *cipher, int iter,

                           unsigned char *salt, int saltlen)

{

    return PKCS5_pbe2_set_iv(cipher, iter, salt, saltlen, NULL, -1);

}

X509_ALGOR *PKCS5_pbkdf2_set(int iter, unsigned char *salt, int saltlen,

                             int prf_nid, int keylen)

{

    X509_ALGOR *keyfunc = NULL;

    PBKDF2PARAM *kdf = NULL;

    ASN1_OCTET_STRING *osalt = NULL;

    if ((kdf = PBKDF2PARAM_new()) == NULL)

        goto merr;

    if ((osalt = ASN1_OCTET_STRING_new()) == NULL)

        goto merr;

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

    kdf->salt->type = V_ASN1_OCTET_STRING;

    if (saltlen == 0)

        saltlen = PKCS5_SALT_LEN;

    if ((osalt->data = OPENSSL_malloc(saltlen)) == NULL)

        goto merr;

    osalt->length = saltlen;

    if (salt)

        memcpy(osalt->data, salt, saltlen);

    else if (RAND_bytes(osalt->data, saltlen) <= 0)

        goto merr;

    if (iter <= 0)

        iter = PKCS5_DEFAULT_ITER;

    if (!ASN1_INTEGER_set(kdf->iter, iter))

        goto merr;

    /* If have a key len set it up */

    if (keylen > 0) {

        if ((kdf->keylength = ASN1_INTEGER_new()) == NULL)

            goto merr;

        if (!ASN1_INTEGER_set(kdf->keylength, keylen))

            goto merr;

    }

    /* prf can stay NULL if we are using hmacWithSHA1 */

    if (prf_nid > 0 && prf_nid != NID_hmacWithSHA1) {

        kdf->prf = X509_ALGOR_new();

        if (kdf->prf == NULL)

            goto merr;

        X509_ALGOR_set0(kdf->prf, OBJ_nid2obj(prf_nid), V_ASN1_NULL, NULL);

    }

    /* Finally setup the keyfunc structure */

    keyfunc = X509_ALGOR_new();

    if (keyfunc == NULL)

        goto merr;

    keyfunc->algorithm = OBJ_nid2obj(NID_id_pbkdf2);

    /* Encode PBKDF2PARAM into parameter of pbe2 */

    if (!ASN1_TYPE_pack_sequence(ASN1_ITEM_rptr(PBKDF2PARAM), kdf,

                                 &keyfunc->parameter))

         goto merr;

    PBKDF2PARAM_free(kdf);

    return keyfunc;

 merr:

    ASN1err(ASN1_F_PKCS5_PBKDF2_SET, ERR_R_MALLOC_FAILURE);

    PBKDF2PARAM_free(kdf);

    X509_ALGOR_free(keyfunc);

    return NULL;

}