/**
 * \file mbedtls_md.c
 *
 * \brief Generic message digest wrapper for mbed TLS
 *
 * \author Adriaan de Jong <dejong@fox-it.com>
 *
 *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
 *  SPDX-License-Identifier: Apache-2.0
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
 *  not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *  This file is part of mbed TLS (https://tls.mbed.org)
 */

#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/mbedtls_config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif

#if defined(MBEDTLS_MD_C)

#include "mbedtls/md.h"
#include "mbedtls/md_internal.h"

#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdlib.h>
#define mbedtls_calloc    calloc
#define mbedtls_free       free
#endif

#include <string.h>

#if defined(MBEDTLS_FS_IO)
#include <stdio.h>
#endif

/* Implementation that should never be optimized out by the compiler */
static void mbedtls_zeroize(void *v, size_t n)
{
    volatile unsigned char *p = v;
    while (n--) {
        *p++ = 0;
    }
}

/*
 * Reminder: update profiles in x509_crt.c when adding a new hash!
 */
static const int supported_digests[] = {

#if defined(MBEDTLS_SHA512_C)
    MBEDTLS_MD_SHA512,
    MBEDTLS_MD_SHA384,
#endif

#if defined(MBEDTLS_SHA256_C)
    MBEDTLS_MD_SHA256,
    MBEDTLS_MD_SHA224,
#endif

#if defined(MBEDTLS_SHA1_C)
    MBEDTLS_MD_SHA1,
#endif

#if defined(MBEDTLS_RIPEMD160_C)
    MBEDTLS_MD_RIPEMD160,
#endif

#if defined(MBEDTLS_MD5_C)
    MBEDTLS_MD_MD5,
#endif

#if defined(MBEDTLS_MD4_C)
    MBEDTLS_MD_MD4,
#endif

#if defined(MBEDTLS_MD2_C)
    MBEDTLS_MD_MD2,
#endif

    MBEDTLS_MD_NONE
};

const int *mbedtls_md_list(void)
{
    return (supported_digests);
}

const mbedtls_md_info_t *mbedtls_md_info_from_string(const char *md_name)
{
    if (NULL == md_name) {
        return (NULL);
    }

    /* Get the appropriate digest information */
#if defined(MBEDTLS_MD2_C)
    if (!strcmp("MD2", md_name)) {
        return mbedtls_md_info_from_type(MBEDTLS_MD_MD2);
    }
#endif
#if defined(MBEDTLS_MD4_C)
    if (!strcmp("MD4", md_name)) {
        return mbedtls_md_info_from_type(MBEDTLS_MD_MD4);
    }
#endif
#if defined(MBEDTLS_MD5_C)
    if (!strcmp("MD5", md_name)) {
        return mbedtls_md_info_from_type(MBEDTLS_MD_MD5);
    }
#endif
#if defined(MBEDTLS_RIPEMD160_C)
    if (!strcmp("RIPEMD160", md_name)) {
        return mbedtls_md_info_from_type(MBEDTLS_MD_RIPEMD160);
    }
#endif
#if defined(MBEDTLS_SHA1_C)
    if (!strcmp("SHA1", md_name) || !strcmp("SHA", md_name)) {
        return mbedtls_md_info_from_type(MBEDTLS_MD_SHA1);
    }
#endif
#if defined(MBEDTLS_SHA256_C)
    if (!strcmp("SHA224", md_name)) {
        return mbedtls_md_info_from_type(MBEDTLS_MD_SHA224);
    }
    if (!strcmp("SHA256", md_name)) {
        return mbedtls_md_info_from_type(MBEDTLS_MD_SHA256);
    }
#endif
#if defined(MBEDTLS_SHA512_C)
    if (!strcmp("SHA384", md_name)) {
        return mbedtls_md_info_from_type(MBEDTLS_MD_SHA384);
    }
    if (!strcmp("SHA512", md_name)) {
        return mbedtls_md_info_from_type(MBEDTLS_MD_SHA512);
    }
#endif
    return (NULL);
}

const mbedtls_md_info_t *mbedtls_md_info_from_type(mbedtls_md_type_t md_type)
{
    switch (md_type) {
#if defined(MBEDTLS_MD2_C)
    case MBEDTLS_MD_MD2:
        return (&mbedtls_md2_info);
#endif
#if defined(MBEDTLS_MD4_C)
    case MBEDTLS_MD_MD4:
        return (&mbedtls_md4_info);
#endif
#if defined(MBEDTLS_MD5_C)
    case MBEDTLS_MD_MD5:
        return (&mbedtls_md5_info);
#endif
#if defined(MBEDTLS_RIPEMD160_C)
    case MBEDTLS_MD_RIPEMD160:
        return (&mbedtls_ripemd160_info);
#endif
#if defined(MBEDTLS_SHA1_C)
    case MBEDTLS_MD_SHA1:
        return (&mbedtls_sha1_info);
#endif
#if defined(MBEDTLS_SHA256_C)
    case MBEDTLS_MD_SHA224:
        return (&mbedtls_sha224_info);
    case MBEDTLS_MD_SHA256:
        return (&mbedtls_sha256_info);
#endif
#if defined(MBEDTLS_SHA512_C)
    case MBEDTLS_MD_SHA384:
        return (&mbedtls_sha384_info);
    case MBEDTLS_MD_SHA512:
        return (&mbedtls_sha512_info);
#endif
    default:
        return (NULL);
    }
}

void mbedtls_md_init(mbedtls_md_context_t *ctx)
{
    memset(ctx, 0, sizeof(mbedtls_md_context_t));
}

void mbedtls_md_free(mbedtls_md_context_t *ctx)
{
    if (ctx == NULL || ctx->md_info == NULL) {
        return;
    }

    if (ctx->md_ctx != NULL) {
        ctx->md_info->ctx_free_func(ctx->md_ctx);
    }

    if (ctx->hmac_ctx != NULL) {
        mbedtls_zeroize(ctx->hmac_ctx, 2 * ctx->md_info->block_size);
        mbedtls_free(ctx->hmac_ctx);
    }

    mbedtls_zeroize(ctx, sizeof(mbedtls_md_context_t));
}

int mbedtls_md_clone(mbedtls_md_context_t *dst,
                     const mbedtls_md_context_t *src)
{
    if (dst == NULL || dst->md_info == NULL ||
        src == NULL || src->md_info == NULL ||
        dst->md_info != src->md_info) {
        return (MBEDTLS_ERR_MD_BAD_INPUT_DATA);
    }

    dst->md_info->clone_func(dst->md_ctx, src->md_ctx);

    return (0);
}

#if ! defined(MBEDTLS_DEPRECATED_REMOVED)
int mbedtls_md_init_ctx(mbedtls_md_context_t *ctx, const mbedtls_md_info_t *md_info)
{
    return mbedtls_md_setup(ctx, md_info, 1);
}
#endif

int mbedtls_md_setup(mbedtls_md_context_t *ctx, const mbedtls_md_info_t *md_info, int hmac)
{
    if (md_info == NULL || ctx == NULL) {
        return (MBEDTLS_ERR_MD_BAD_INPUT_DATA);
    }

    if ((ctx->md_ctx = md_info->ctx_alloc_func()) == NULL) {
        return (MBEDTLS_ERR_MD_ALLOC_FAILED);
    }

    if (hmac != 0) {
        ctx->hmac_ctx = mbedtls_calloc(2, md_info->block_size);
        if (ctx->hmac_ctx == NULL) {
            md_info->ctx_free_func(ctx->md_ctx);
            return (MBEDTLS_ERR_MD_ALLOC_FAILED);
        }
    }

    ctx->md_info = md_info;

    return (0);
}

int mbedtls_md_starts(mbedtls_md_context_t *ctx)
{
    if (ctx == NULL || ctx->md_info == NULL) {
        return (MBEDTLS_ERR_MD_BAD_INPUT_DATA);
    }

    ctx->md_info->starts_func(ctx->md_ctx);

    return (0);
}

int mbedtls_md_update(mbedtls_md_context_t *ctx, const unsigned char *input, size_t ilen)
{
    if (ctx == NULL || ctx->md_info == NULL) {
        return (MBEDTLS_ERR_MD_BAD_INPUT_DATA);
    }

    ctx->md_info->update_func(ctx->md_ctx, input, ilen);

    return (0);
}

int mbedtls_md_finish(mbedtls_md_context_t *ctx, unsigned char *output)
{
    if (ctx == NULL || ctx->md_info == NULL) {
        return (MBEDTLS_ERR_MD_BAD_INPUT_DATA);
    }

    ctx->md_info->finish_func(ctx->md_ctx, output);

    return (0);
}

int mbedtls_md(const mbedtls_md_info_t *md_info, const unsigned char *input, size_t ilen,
               unsigned char *output)
{
    if (md_info == NULL) {
        return (MBEDTLS_ERR_MD_BAD_INPUT_DATA);
    }

    md_info->digest_func(input, ilen, output);

    return (0);
}

#if defined(MBEDTLS_FS_IO)
int mbedtls_md_file(const mbedtls_md_info_t *md_info, const char *path, unsigned char *output)
{
    int ret;
    FILE *f;
    size_t n;
    mbedtls_md_context_t ctx;
    unsigned char buf[1024];

    if (md_info == NULL) {
        return (MBEDTLS_ERR_MD_BAD_INPUT_DATA);
    }

    if ((f = fopen(path, "rb")) == NULL) {
        return (MBEDTLS_ERR_MD_FILE_IO_ERROR);
    }

    mbedtls_md_init(&ctx);

    if ((ret = mbedtls_md_setup(&ctx, md_info, 0)) != 0) {
        goto cleanup;
    }

    md_info->starts_func(ctx.md_ctx);

    while ((n = fread(buf, 1, sizeof(buf), f)) > 0) {
        md_info->update_func(ctx.md_ctx, buf, n);
    }

    if (ferror(f) != 0) {
        ret = MBEDTLS_ERR_MD_FILE_IO_ERROR;
        goto cleanup;
    }

    md_info->finish_func(ctx.md_ctx, output);

cleanup:
    fclose(f);
    mbedtls_md_free(&ctx);

    return (ret);
}
#endif /* MBEDTLS_FS_IO */

int mbedtls_md_hmac_starts(mbedtls_md_context_t *ctx, const unsigned char *key, size_t keylen)
{
    unsigned char sum[MBEDTLS_MD_MAX_SIZE];
    unsigned char *ipad, *opad;
    size_t i;

    if (ctx == NULL || ctx->md_info == NULL || ctx->hmac_ctx == NULL) {
        return (MBEDTLS_ERR_MD_BAD_INPUT_DATA);
    }

    if (keylen > (size_t) ctx->md_info->block_size) {
        ctx->md_info->starts_func(ctx->md_ctx);
        ctx->md_info->update_func(ctx->md_ctx, key, keylen);
        ctx->md_info->finish_func(ctx->md_ctx, sum);

        keylen = ctx->md_info->size;
        key = sum;
    }

    ipad = (unsigned char *) ctx->hmac_ctx;
    opad = (unsigned char *) ctx->hmac_ctx + ctx->md_info->block_size;

    memset(ipad, 0x36, ctx->md_info->block_size);
    memset(opad, 0x5C, ctx->md_info->block_size);

    for (i = 0; i < keylen; i++) {
        ipad[i] = (unsigned char)(ipad[i] ^ key[i]);
        opad[i] = (unsigned char)(opad[i] ^ key[i]);
    }

    mbedtls_zeroize(sum, sizeof(sum));

    ctx->md_info->starts_func(ctx->md_ctx);
    ctx->md_info->update_func(ctx->md_ctx, ipad, ctx->md_info->block_size);

    return (0);
}

int mbedtls_md_hmac_update(mbedtls_md_context_t *ctx, const unsigned char *input, size_t ilen)
{
    if (ctx == NULL || ctx->md_info == NULL || ctx->hmac_ctx == NULL) {
        return (MBEDTLS_ERR_MD_BAD_INPUT_DATA);
    }

    ctx->md_info->update_func(ctx->md_ctx, input, ilen);

    return (0);
}

int mbedtls_md_hmac_finish(mbedtls_md_context_t *ctx, unsigned char *output)
{
    unsigned char tmp[MBEDTLS_MD_MAX_SIZE];
    unsigned char *opad;

    if (ctx == NULL || ctx->md_info == NULL || ctx->hmac_ctx == NULL) {
        return (MBEDTLS_ERR_MD_BAD_INPUT_DATA);
    }

    opad = (unsigned char *) ctx->hmac_ctx + ctx->md_info->block_size;

    ctx->md_info->finish_func(ctx->md_ctx, tmp);
    ctx->md_info->starts_func(ctx->md_ctx);
    ctx->md_info->update_func(ctx->md_ctx, opad, ctx->md_info->block_size);
    ctx->md_info->update_func(ctx->md_ctx, tmp, ctx->md_info->size);
    ctx->md_info->finish_func(ctx->md_ctx, output);

    return (0);
}

int mbedtls_md_hmac_reset(mbedtls_md_context_t *ctx)
{
    unsigned char *ipad;

    if (ctx == NULL || ctx->md_info == NULL || ctx->hmac_ctx == NULL) {
        return (MBEDTLS_ERR_MD_BAD_INPUT_DATA);
    }

    ipad = (unsigned char *) ctx->hmac_ctx;

    ctx->md_info->starts_func(ctx->md_ctx);
    ctx->md_info->update_func(ctx->md_ctx, ipad, ctx->md_info->block_size);

    return (0);
}

int mbedtls_md_hmac(const mbedtls_md_info_t *md_info, const unsigned char *key, size_t keylen,
                    const unsigned char *input, size_t ilen,
                    unsigned char *output)
{
    mbedtls_md_context_t ctx;
    int ret;

    if (md_info == NULL) {
        return (MBEDTLS_ERR_MD_BAD_INPUT_DATA);
    }

    mbedtls_md_init(&ctx);

    if ((ret = mbedtls_md_setup(&ctx, md_info, 1)) != 0) {
        return (ret);
    }

    mbedtls_md_hmac_starts(&ctx, key, keylen);
    mbedtls_md_hmac_update(&ctx, input, ilen);
    mbedtls_md_hmac_finish(&ctx, output);

    mbedtls_md_free(&ctx);

    return (0);
}

int mbedtls_md_process(mbedtls_md_context_t *ctx, const unsigned char *data)
{
    if (ctx == NULL || ctx->md_info == NULL) {
        return (MBEDTLS_ERR_MD_BAD_INPUT_DATA);
    }

    ctx->md_info->process_func(ctx->md_ctx, data);

    return (0);
}

unsigned char mbedtls_md_get_size(const mbedtls_md_info_t *md_info)
{
    if (md_info == NULL) {
        return (0);
    }

    return md_info->size;
}

mbedtls_md_type_t mbedtls_md_get_type(const mbedtls_md_info_t *md_info)
{
    if (md_info == NULL) {
        return (MBEDTLS_MD_NONE);
    }

    return md_info->type;
}

const char *mbedtls_md_get_name(const mbedtls_md_info_t *md_info)
{
    if (md_info == NULL) {
        return (NULL);
    }

    return md_info->name;
}

#endif /* MBEDTLS_MD_C */