/*
 *  RFC 1321 compliant MD5 implementation
 *
 *  Copyright The Mbed TLS Contributors
 *  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.
 */
/*
 *  The MD5 algorithm was designed by Ron Rivest in 1991.
 *
 *  http://www.ietf.org/rfc/rfc1321.txt
 */

#include "common.h"

#if defined(MBEDTLS_MD5_C)

#include "mbedtls/md5.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/error.h"

#include <string.h>

#include "mbedtls/platform.h"

#if !defined(MBEDTLS_MD5_ALT)

void mbedtls_md5_init(mbedtls_md5_context *ctx)
{
    memset(ctx, 0, sizeof(mbedtls_md5_context));
}

void mbedtls_md5_free(mbedtls_md5_context *ctx)
{
    if (ctx == NULL) {
        return;
    }

    mbedtls_platform_zeroize(ctx, sizeof(mbedtls_md5_context));
}

void mbedtls_md5_clone(mbedtls_md5_context *dst,
                       const mbedtls_md5_context *src)
{
    *dst = *src;
}

/*
 * MD5 context setup
 */
int mbedtls_md5_starts(mbedtls_md5_context *ctx)
{
    ctx->total[0] = 0;
    ctx->total[1] = 0;

    ctx->state[0] = 0x67452301;
    ctx->state[1] = 0xEFCDAB89;
    ctx->state[2] = 0x98BADCFE;
    ctx->state[3] = 0x10325476;

    return 0;
}

#if !defined(MBEDTLS_MD5_PROCESS_ALT)
int mbedtls_internal_md5_process(mbedtls_md5_context *ctx,
                                 const unsigned char data[64])
{
    struct {
        uint32_t X[16], A, B, C, D;
    } local;

    local.X[0] = MBEDTLS_GET_UINT32_LE(data,  0);
    local.X[1] = MBEDTLS_GET_UINT32_LE(data,  4);
    local.X[2] = MBEDTLS_GET_UINT32_LE(data,  8);
    local.X[3] = MBEDTLS_GET_UINT32_LE(data, 12);
    local.X[4] = MBEDTLS_GET_UINT32_LE(data, 16);
    local.X[5] = MBEDTLS_GET_UINT32_LE(data, 20);
    local.X[6] = MBEDTLS_GET_UINT32_LE(data, 24);
    local.X[7] = MBEDTLS_GET_UINT32_LE(data, 28);
    local.X[8] = MBEDTLS_GET_UINT32_LE(data, 32);
    local.X[9] = MBEDTLS_GET_UINT32_LE(data, 36);
    local.X[10] = MBEDTLS_GET_UINT32_LE(data, 40);
    local.X[11] = MBEDTLS_GET_UINT32_LE(data, 44);
    local.X[12] = MBEDTLS_GET_UINT32_LE(data, 48);
    local.X[13] = MBEDTLS_GET_UINT32_LE(data, 52);
    local.X[14] = MBEDTLS_GET_UINT32_LE(data, 56);
    local.X[15] = MBEDTLS_GET_UINT32_LE(data, 60);

#define S(x, n)                                                          \
    (((x) << (n)) | (((x) & 0xFFFFFFFF) >> (32 - (n))))

#define P(a, b, c, d, k, s, t)                                                \
    do                                                                  \
    {                                                                   \
        (a) += F((b), (c), (d)) + local.X[(k)] + (t);                     \
        (a) = S((a), (s)) + (b);                                         \
    } while (0)

    local.A = ctx->state[0];
    local.B = ctx->state[1];
    local.C = ctx->state[2];
    local.D = ctx->state[3];

#define F(x, y, z) ((z) ^ ((x) & ((y) ^ (z))))

    P(local.A, local.B, local.C, local.D,  0,  7, 0xD76AA478);
    P(local.D, local.A, local.B, local.C,  1, 12, 0xE8C7B756);
    P(local.C, local.D, local.A, local.B,  2, 17, 0x242070DB);
    P(local.B, local.C, local.D, local.A,  3, 22, 0xC1BDCEEE);
    P(local.A, local.B, local.C, local.D,  4,  7, 0xF57C0FAF);
    P(local.D, local.A, local.B, local.C,  5, 12, 0x4787C62A);
    P(local.C, local.D, local.A, local.B,  6, 17, 0xA8304613);
    P(local.B, local.C, local.D, local.A,  7, 22, 0xFD469501);
    P(local.A, local.B, local.C, local.D,  8,  7, 0x698098D8);
    P(local.D, local.A, local.B, local.C,  9, 12, 0x8B44F7AF);
    P(local.C, local.D, local.A, local.B, 10, 17, 0xFFFF5BB1);
    P(local.B, local.C, local.D, local.A, 11, 22, 0x895CD7BE);
    P(local.A, local.B, local.C, local.D, 12,  7, 0x6B901122);
    P(local.D, local.A, local.B, local.C, 13, 12, 0xFD987193);
    P(local.C, local.D, local.A, local.B, 14, 17, 0xA679438E);
    P(local.B, local.C, local.D, local.A, 15, 22, 0x49B40821);

#undef F

#define F(x, y, z) ((y) ^ ((z) & ((x) ^ (y))))

    P(local.A, local.B, local.C, local.D,  1,  5, 0xF61E2562);
    P(local.D, local.A, local.B, local.C,  6,  9, 0xC040B340);
    P(local.C, local.D, local.A, local.B, 11, 14, 0x265E5A51);
    P(local.B, local.C, local.D, local.A,  0, 20, 0xE9B6C7AA);
    P(local.A, local.B, local.C, local.D,  5,  5, 0xD62F105D);
    P(local.D, local.A, local.B, local.C, 10,  9, 0x02441453);
    P(local.C, local.D, local.A, local.B, 15, 14, 0xD8A1E681);
    P(local.B, local.C, local.D, local.A,  4, 20, 0xE7D3FBC8);
    P(local.A, local.B, local.C, local.D,  9,  5, 0x21E1CDE6);
    P(local.D, local.A, local.B, local.C, 14,  9, 0xC33707D6);
    P(local.C, local.D, local.A, local.B,  3, 14, 0xF4D50D87);
    P(local.B, local.C, local.D, local.A,  8, 20, 0x455A14ED);
    P(local.A, local.B, local.C, local.D, 13,  5, 0xA9E3E905);
    P(local.D, local.A, local.B, local.C,  2,  9, 0xFCEFA3F8);
    P(local.C, local.D, local.A, local.B,  7, 14, 0x676F02D9);
    P(local.B, local.C, local.D, local.A, 12, 20, 0x8D2A4C8A);

#undef F

#define F(x, y, z) ((x) ^ (y) ^ (z))

    P(local.A, local.B, local.C, local.D,  5,  4, 0xFFFA3942);
    P(local.D, local.A, local.B, local.C,  8, 11, 0x8771F681);
    P(local.C, local.D, local.A, local.B, 11, 16, 0x6D9D6122);
    P(local.B, local.C, local.D, local.A, 14, 23, 0xFDE5380C);
    P(local.A, local.B, local.C, local.D,  1,  4, 0xA4BEEA44);
    P(local.D, local.A, local.B, local.C,  4, 11, 0x4BDECFA9);
    P(local.C, local.D, local.A, local.B,  7, 16, 0xF6BB4B60);
    P(local.B, local.C, local.D, local.A, 10, 23, 0xBEBFBC70);
    P(local.A, local.B, local.C, local.D, 13,  4, 0x289B7EC6);
    P(local.D, local.A, local.B, local.C,  0, 11, 0xEAA127FA);
    P(local.C, local.D, local.A, local.B,  3, 16, 0xD4EF3085);
    P(local.B, local.C, local.D, local.A,  6, 23, 0x04881D05);
    P(local.A, local.B, local.C, local.D,  9,  4, 0xD9D4D039);
    P(local.D, local.A, local.B, local.C, 12, 11, 0xE6DB99E5);
    P(local.C, local.D, local.A, local.B, 15, 16, 0x1FA27CF8);
    P(local.B, local.C, local.D, local.A,  2, 23, 0xC4AC5665);

#undef F

#define F(x, y, z) ((y) ^ ((x) | ~(z)))

    P(local.A, local.B, local.C, local.D,  0,  6, 0xF4292244);
    P(local.D, local.A, local.B, local.C,  7, 10, 0x432AFF97);
    P(local.C, local.D, local.A, local.B, 14, 15, 0xAB9423A7);
    P(local.B, local.C, local.D, local.A,  5, 21, 0xFC93A039);
    P(local.A, local.B, local.C, local.D, 12,  6, 0x655B59C3);
    P(local.D, local.A, local.B, local.C,  3, 10, 0x8F0CCC92);
    P(local.C, local.D, local.A, local.B, 10, 15, 0xFFEFF47D);
    P(local.B, local.C, local.D, local.A,  1, 21, 0x85845DD1);
    P(local.A, local.B, local.C, local.D,  8,  6, 0x6FA87E4F);
    P(local.D, local.A, local.B, local.C, 15, 10, 0xFE2CE6E0);
    P(local.C, local.D, local.A, local.B,  6, 15, 0xA3014314);
    P(local.B, local.C, local.D, local.A, 13, 21, 0x4E0811A1);
    P(local.A, local.B, local.C, local.D,  4,  6, 0xF7537E82);
    P(local.D, local.A, local.B, local.C, 11, 10, 0xBD3AF235);
    P(local.C, local.D, local.A, local.B,  2, 15, 0x2AD7D2BB);
    P(local.B, local.C, local.D, local.A,  9, 21, 0xEB86D391);

#undef F

    ctx->state[0] += local.A;
    ctx->state[1] += local.B;
    ctx->state[2] += local.C;
    ctx->state[3] += local.D;

    /* Zeroise variables to clear sensitive data from memory. */
    mbedtls_platform_zeroize(&local, sizeof(local));

    return 0;
}

#endif /* !MBEDTLS_MD5_PROCESS_ALT */

/*
 * MD5 process buffer
 */
int mbedtls_md5_update(mbedtls_md5_context *ctx,
                       const unsigned char *input,
                       size_t ilen)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    size_t fill;
    uint32_t left;

    if (ilen == 0) {
        return 0;
    }

    left = ctx->total[0] & 0x3F;
    fill = 64 - left;

    ctx->total[0] += (uint32_t) ilen;
    ctx->total[0] &= 0xFFFFFFFF;

    if (ctx->total[0] < (uint32_t) ilen) {
        ctx->total[1]++;
    }

    if (left && ilen >= fill) {
        memcpy((void *) (ctx->buffer + left), input, fill);
        if ((ret = mbedtls_internal_md5_process(ctx, ctx->buffer)) != 0) {
            return ret;
        }

        input += fill;
        ilen  -= fill;
        left = 0;
    }

    while (ilen >= 64) {
        if ((ret = mbedtls_internal_md5_process(ctx, input)) != 0) {
            return ret;
        }

        input += 64;
        ilen  -= 64;
    }

    if (ilen > 0) {
        memcpy((void *) (ctx->buffer + left), input, ilen);
    }

    return 0;
}

/*
 * MD5 final digest
 */
int mbedtls_md5_finish(mbedtls_md5_context *ctx,
                       unsigned char output[16])
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    uint32_t used;
    uint32_t high, low;

    /*
     * Add padding: 0x80 then 0x00 until 8 bytes remain for the length
     */
    used = ctx->total[0] & 0x3F;

    ctx->buffer[used++] = 0x80;

    if (used <= 56) {
        /* Enough room for padding + length in current block */
        memset(ctx->buffer + used, 0, 56 - used);
    } else {
        /* We'll need an extra block */
        memset(ctx->buffer + used, 0, 64 - used);

        if ((ret = mbedtls_internal_md5_process(ctx, ctx->buffer)) != 0) {
            goto exit;
        }

        memset(ctx->buffer, 0, 56);
    }

    /*
     * Add message length
     */
    high = (ctx->total[0] >> 29)
           | (ctx->total[1] <<  3);
    low  = (ctx->total[0] <<  3);

    MBEDTLS_PUT_UINT32_LE(low,  ctx->buffer, 56);
    MBEDTLS_PUT_UINT32_LE(high, ctx->buffer, 60);

    if ((ret = mbedtls_internal_md5_process(ctx, ctx->buffer)) != 0) {
        goto exit;
    }

    /*
     * Output final state
     */
    MBEDTLS_PUT_UINT32_LE(ctx->state[0], output,  0);
    MBEDTLS_PUT_UINT32_LE(ctx->state[1], output,  4);
    MBEDTLS_PUT_UINT32_LE(ctx->state[2], output,  8);
    MBEDTLS_PUT_UINT32_LE(ctx->state[3], output, 12);

    ret = 0;

exit:
    mbedtls_md5_free(ctx);
    return ret;
}

#endif /* !MBEDTLS_MD5_ALT */

/*
 * output = MD5( input buffer )
 */
int mbedtls_md5(const unsigned char *input,
                size_t ilen,
                unsigned char output[16])
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    mbedtls_md5_context ctx;

    mbedtls_md5_init(&ctx);

    if ((ret = mbedtls_md5_starts(&ctx)) != 0) {
        goto exit;
    }

    if ((ret = mbedtls_md5_update(&ctx, input, ilen)) != 0) {
        goto exit;
    }

    if ((ret = mbedtls_md5_finish(&ctx, output)) != 0) {
        goto exit;
    }

exit:
    mbedtls_md5_free(&ctx);

    return ret;
}

#if defined(MBEDTLS_SELF_TEST)
/*
 * RFC 1321 test vectors
 */
static const unsigned char md5_test_buf[7][81] =
{
    { "" },
    { "a" },
    { "abc" },
    { "message digest" },
    { "abcdefghijklmnopqrstuvwxyz" },
    { "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" },
    { "12345678901234567890123456789012345678901234567890123456789012345678901234567890" }
};

static const size_t md5_test_buflen[7] =
{
    0, 1, 3, 14, 26, 62, 80
};

static const unsigned char md5_test_sum[7][16] =
{
    { 0xD4, 0x1D, 0x8C, 0xD9, 0x8F, 0x00, 0xB2, 0x04,
      0xE9, 0x80, 0x09, 0x98, 0xEC, 0xF8, 0x42, 0x7E },
    { 0x0C, 0xC1, 0x75, 0xB9, 0xC0, 0xF1, 0xB6, 0xA8,
      0x31, 0xC3, 0x99, 0xE2, 0x69, 0x77, 0x26, 0x61 },
    { 0x90, 0x01, 0x50, 0x98, 0x3C, 0xD2, 0x4F, 0xB0,
      0xD6, 0x96, 0x3F, 0x7D, 0x28, 0xE1, 0x7F, 0x72 },
    { 0xF9, 0x6B, 0x69, 0x7D, 0x7C, 0xB7, 0x93, 0x8D,
      0x52, 0x5A, 0x2F, 0x31, 0xAA, 0xF1, 0x61, 0xD0 },
    { 0xC3, 0xFC, 0xD3, 0xD7, 0x61, 0x92, 0xE4, 0x00,
      0x7D, 0xFB, 0x49, 0x6C, 0xCA, 0x67, 0xE1, 0x3B },
    { 0xD1, 0x74, 0xAB, 0x98, 0xD2, 0x77, 0xD9, 0xF5,
      0xA5, 0x61, 0x1C, 0x2C, 0x9F, 0x41, 0x9D, 0x9F },
    { 0x57, 0xED, 0xF4, 0xA2, 0x2B, 0xE3, 0xC9, 0x55,
      0xAC, 0x49, 0xDA, 0x2E, 0x21, 0x07, 0xB6, 0x7A }
};

/*
 * Checkup routine
 */
int mbedtls_md5_self_test(int verbose)
{
    int i, ret = 0;
    unsigned char md5sum[16];

    for (i = 0; i < 7; i++) {
        if (verbose != 0) {
            mbedtls_printf("  MD5 test #%d: ", i + 1);
        }

        ret = mbedtls_md5(md5_test_buf[i], md5_test_buflen[i], md5sum);
        if (ret != 0) {
            goto fail;
        }

        if (memcmp(md5sum, md5_test_sum[i], 16) != 0) {
            ret = 1;
            goto fail;
        }

        if (verbose != 0) {
            mbedtls_printf("passed\n");
        }
    }

    if (verbose != 0) {
        mbedtls_printf("\n");
    }

    return 0;

fail:
    if (verbose != 0) {
        mbedtls_printf("failed\n");
    }

    return ret;
}

#endif /* MBEDTLS_SELF_TEST */

#endif /* MBEDTLS_MD5_C */