md5.c

/*
 *  RFC 1321 compliant MD5 implementation
 *
 *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
 *  Copyright (C) 2016-2017, Kaspter Ju, 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.
 *
 */
/*
 *  The MD5 algorithm was designed by Ron Rivest in 1991.
 *
 *  http://www.ietf.org/rfc/rfc1321.txt
 */

#include "md5.h"

#include <stdio.h>
#include <string.h>

#define mbedtls_printf printf

/* 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;
}

/*
 * 32-bit integer manipulation macros (little endian)
 */
#ifndef GET_UINT32_LE
#define GET_UINT32_LE(n, b, i)                \
    {                                         \
        (n) = ((uint32_t)(b)[(i)])            \
            | ((uint32_t)(b)[(i) + 1] << 8)   \
            | ((uint32_t)(b)[(i) + 2] << 16)  \
            | ((uint32_t)(b)[(i) + 3] << 24); \
    }
#endif

#ifndef PUT_UINT32_LE
#define PUT_UINT32_LE(n, b, i)                              \
    {                                                       \
        (b)[(i)]     = (unsigned char)(((n)) & 0xFF);       \
        (b)[(i) + 1] = (unsigned char)(((n) >> 8) & 0xFF);  \
        (b)[(i) + 2] = (unsigned char)(((n) >> 16) & 0xFF); \
        (b)[(i) + 3] = (unsigned char)(((n) >> 24) & 0xFF); \
    }
#endif

void md5_init(md5_context* ctx)
{
    memset(ctx, 0, sizeof(md5_context));
}

void md5_free(md5_context* ctx)
{
    if (ctx == NULL)
        return;

    mbedtls_zeroize(ctx, sizeof(md5_context));
}

void md5_clone(md5_context*       dst,
               const md5_context* src)
{
    *dst = *src;
}

/*
 * MD5 context setup
 */
void md5_starts(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;
}

void md5_process(md5_context* ctx, const unsigned char data[64])
{
    uint32_t X[16], A, B, C, D;

    GET_UINT32_LE(X[0], data, 0);
    GET_UINT32_LE(X[1], data, 4);
    GET_UINT32_LE(X[2], data, 8);
    GET_UINT32_LE(X[3], data, 12);
    GET_UINT32_LE(X[4], data, 16);
    GET_UINT32_LE(X[5], data, 20);
    GET_UINT32_LE(X[6], data, 24);
    GET_UINT32_LE(X[7], data, 28);
    GET_UINT32_LE(X[8], data, 32);
    GET_UINT32_LE(X[9], data, 36);
    GET_UINT32_LE(X[10], data, 40);
    GET_UINT32_LE(X[11], data, 44);
    GET_UINT32_LE(X[12], data, 48);
    GET_UINT32_LE(X[13], data, 52);
    GET_UINT32_LE(X[14], data, 56);
    GET_UINT32_LE(X[15], data, 60);

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

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

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

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

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

#undef F

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

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

#undef F

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

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

#undef F

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

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

#undef F

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

/*
 * MD5 process buffer
 */
void md5_update(md5_context* ctx, const unsigned char* input, size_t ilen)
{
    size_t   fill;
    uint32_t left;

    if (ilen == 0)
        return;

    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);
        md5_process(ctx, ctx->buffer);
        input += fill;
        ilen -= fill;
        left = 0;
    }

    while (ilen >= 64) {
        md5_process(ctx, input);
        input += 64;
        ilen -= 64;
    }

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

static const unsigned char md5_padding[64] = {
    0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

/*
 * MD5 final digest
 */
void md5_finish(md5_context* ctx, unsigned char output[16])
{
    uint32_t      last, padn;
    uint32_t      high, low;
    unsigned char msglen[8];

    high = (ctx->total[0] >> 29)
        | (ctx->total[1] << 3);
    low = (ctx->total[0] << 3);

    PUT_UINT32_LE(low, msglen, 0);
    PUT_UINT32_LE(high, msglen, 4);

    last = ctx->total[0] & 0x3F;
    padn = (last < 56) ? (56 - last) : (120 - last);

    md5_update(ctx, md5_padding, padn);
    md5_update(ctx, msglen, 8);

    PUT_UINT32_LE(ctx->state[0], output, 0);
    PUT_UINT32_LE(ctx->state[1], output, 4);
    PUT_UINT32_LE(ctx->state[2], output, 8);
    PUT_UINT32_LE(ctx->state[3], output, 12);
}

/*
 * output = MD5( input buffer )
 */
void md5(const unsigned char* input, size_t ilen, unsigned char output[16])
{
    md5_context ctx;

    md5_init(&ctx);
    md5_starts(&ctx);
    md5_update(&ctx, input, ilen);
    md5_finish(&ctx, output);
    md5_free(&ctx);
}

/*
 * output = MD5( file contents )
 */
int md5_file(const char* path, unsigned char output[16])
{
    FILE*         f;
    size_t        n;
    md5_context   ctx;
    unsigned char buf[1024];

    if ((f = fopen(path, "rb")) == NULL)
        return (ERR_MD5_FILE_IO_ERROR);

    md5_init(&ctx);
    md5_starts(&ctx);

    while ((n = fread(buf, 1, sizeof(buf), f)) > 0)
        md5_update(&ctx, buf, n);

    md5_finish(&ctx, output);
    md5_free(&ctx);

    if (ferror(f) != 0) {
        fclose(f);
        return (ERR_MD5_FILE_IO_ERROR);
    }

    fclose(f);
    return (0);
}

#if defined(MBEDTLS_SELF_TEST)
/*
 * RFC 1321 test vectors
 */
static const unsigned char md5_test_buf[7][81] = {
    { "" },
    { "a" },
    { "abc" },
    { "message digest" },
    { "abcdefghijklmnopqrstuvwxyz" },
    { "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" },
    { "12345678901234567890123456789012345678901234567890123456789012"
      "345678901234567890" }
};

static const int 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 md5_self_test(int verbose)
{
    int           i;
    unsigned char md5sum[16];

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

        md5(md5_test_buf[i], md5_test_buflen[i], md5sum);

        if (memcmp(md5sum, md5_test_sum[i], 16) != 0) {
            if (verbose != 0)
                mbedtls_printf("failed\n");

            return (1);
        }

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

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

    return (0);
}

#endif /* MBEDTLS_SELF_TEST */