/*
 * Copyright 2015-2019 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the Apache License 2.0 (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 <string.h>
#include "internal/md5_sha1.h"
#include <openssl/evp.h>

int md5_sha1_init(MD5_SHA1_CTX *mctx)
{
    if (!MD5_Init(&mctx->md5))
        return 0;
    return SHA1_Init(&mctx->sha1);
}

int md5_sha1_update(MD5_SHA1_CTX *mctx, const void *data, size_t count)
{
    if (!MD5_Update(&mctx->md5, data, count))
        return 0;
    return SHA1_Update(&mctx->sha1, data, count);
}

int md5_sha1_final(unsigned char *md, MD5_SHA1_CTX *mctx)
{
    if (!MD5_Final(md, &mctx->md5))
        return 0;
    return SHA1_Final(md + MD5_DIGEST_LENGTH, &mctx->sha1);
}

int md5_sha1_ctrl(MD5_SHA1_CTX *mctx, int cmd, int mslen, void *ms)
{
    unsigned char padtmp[48];
    unsigned char md5tmp[MD5_DIGEST_LENGTH];
    unsigned char sha1tmp[SHA_DIGEST_LENGTH];

    if (cmd != EVP_CTRL_SSL3_MASTER_SECRET)
        return -2;

    if (mctx == NULL)
        return 0;

    /* SSLv3 client auth handling: see RFC-6101 5.6.8 */
    if (mslen != 48)
        return 0;

    /* At this point hash contains all handshake messages, update
     * with master secret and pad_1.
     */

    if (md5_sha1_update(mctx, ms, mslen) <= 0)
        return 0;

    /* Set padtmp to pad_1 value */
    memset(padtmp, 0x36, sizeof(padtmp));

    if (!MD5_Update(&mctx->md5, padtmp, sizeof(padtmp)))
        return 0;

    if (!MD5_Final(md5tmp, &mctx->md5))
        return 0;

    if (!SHA1_Update(&mctx->sha1, padtmp, 40))
        return 0;

    if (!SHA1_Final(sha1tmp, &mctx->sha1))
        return 0;

    /* Reinitialise context */

    if (!md5_sha1_init(mctx))
        return 0;

    if (md5_sha1_update(mctx, ms, mslen) <= 0)
        return 0;

    /* Set padtmp to pad_2 value */
    memset(padtmp, 0x5c, sizeof(padtmp));

    if (!MD5_Update(&mctx->md5, padtmp, sizeof(padtmp)))
        return 0;

    if (!MD5_Update(&mctx->md5, md5tmp, sizeof(md5tmp)))
        return 0;

    if (!SHA1_Update(&mctx->sha1, padtmp, 40))
        return 0;

    if (!SHA1_Update(&mctx->sha1, sha1tmp, sizeof(sha1tmp)))
        return 0;

    /* Now when ctx is finalised it will return the SSL v3 hash value */

    OPENSSL_cleanse(md5tmp, sizeof(md5tmp));
    OPENSSL_cleanse(sha1tmp, sizeof(sha1tmp));

    return 1;
}
