/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */

/* lib/crypto/openssl/hash_provider/hash_evp.c - OpenSSL hash providers */

/*

 * Copyright (C) 2015 by the Massachusetts Institute of Technology.

 * All rights reserved.

 *

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

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * * Redistributions of source code must retain the above copyright

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

 *

 * * 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.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "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

 * COPYRIGHT HOLDER 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.

 */

#include "crypto_int.h"

#include <openssl/evp.h>

static krb5_error_code

hash_evp(const EVP_MD *type, const krb5_crypto_iov *data, size_t num_data,

         krb5_data *output)

{

    EVP_MD_CTX *ctx;

    const krb5_data *d;

    size_t i;

    int ok;

    if (output->length != (unsigned int)EVP_MD_size(type))

        return KRB5_CRYPTO_INTERNAL;

    ctx = EVP_MD_CTX_new();

    if (ctx == NULL)

        return ENOMEM;

    if (type == EVP_md4() || type == EVP_md5()) {

        /* See comments below in hash_md4() and hash_md5(). */

        EVP_MD_CTX_set_flags(ctx, EVP_MD_CTX_FLAG_NON_FIPS_ALLOW);

    }

    ok = EVP_DigestInit_ex(ctx, type, NULL);

    for (i = 0; i < num_data; i++) {

        if (!SIGN_IOV(&data[i]))

            continue;

        d = &data[i].data;

        ok = ok && EVP_DigestUpdate(ctx, d->data, d->length);

    }

    ok = ok && EVP_DigestFinal_ex(ctx, (uint8_t *)output->data, NULL);

    EVP_MD_CTX_free(ctx);

    return ok ? 0 : KRB5_CRYPTO_INTERNAL;

}

static krb5_error_code

hash_md4(const krb5_crypto_iov *data, size_t num_data, krb5_data *output)

{

    /*

     * MD4 is needed in FIPS mode to perform key generation for RC4 keys used

     * by IPA.  These keys are only used along a (separately) secured channel

     * for legacy reasons when performing trusts to Active Directory.

     */

    return hash_evp(EVP_md4(), data, num_data, output);

}

static krb5_error_code

hash_md5(const krb5_crypto_iov *data, size_t num_data, krb5_data *output)

{

    /* MD5 is needed in FIPS mode for communication with RADIUS servers.  This

     * is gated in libkrad by libdefaults->radius_md5_fips_override. */

    return hash_evp(EVP_md5(), data, num_data, output);

}

static krb5_error_code

hash_sha1(const krb5_crypto_iov *data, size_t num_data, krb5_data *output)

{

    return hash_evp(EVP_sha1(), data, num_data, output);

}

static krb5_error_code

hash_sha256(const krb5_crypto_iov *data, size_t num_data, krb5_data *output)

{

    return hash_evp(EVP_sha256(), data, num_data, output);

}

static krb5_error_code

hash_sha384(const krb5_crypto_iov *data, size_t num_data, krb5_data *output)

{

    return hash_evp(EVP_sha384(), data, num_data, output);

}

const struct krb5_hash_provider krb5int_hash_md4 = {

    "MD4", 16, 64, hash_md4

};

const struct krb5_hash_provider krb5int_hash_md5 = {

    "MD5", 16, 64, hash_md5

};

const struct krb5_hash_provider krb5int_hash_sha1 = {

    "SHA1", 20, 64, hash_sha1

};

const struct krb5_hash_provider krb5int_hash_sha256 = {

    "SHA-256", 32, 64, hash_sha256

};

const struct krb5_hash_provider krb5int_hash_sha384 = {

    "SHA-384", 48, 128, hash_sha384

};