/*
 *  RFC 1115/1319 compliant MD2 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 MD2 algorithm was designed by Ron Rivest in 1989.
 *
 *  http://www.ietf.org/rfc/rfc1115.txt
 *  http://www.ietf.org/rfc/rfc1319.txt
 */

#include "common.h"

#if defined(MBEDTLS_MD2_C)

#include "mbedtls/md2.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/error.h"

#include <string.h>

#if defined(MBEDTLS_SELF_TEST)
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdio.h>
#define mbedtls_printf printf
#endif /* MBEDTLS_PLATFORM_C */
#endif /* MBEDTLS_SELF_TEST */

#if !defined(MBEDTLS_MD2_ALT)

static const unsigned char PI_SUBST[256] = {
    0x29, 0x2E, 0x43, 0xC9, 0xA2, 0xD8, 0x7C, 0x01, 0x3D, 0x36,
    0x54, 0xA1, 0xEC, 0xF0, 0x06, 0x13, 0x62, 0xA7, 0x05, 0xF3,
    0xC0, 0xC7, 0x73, 0x8C, 0x98, 0x93, 0x2B, 0xD9, 0xBC, 0x4C,
    0x82, 0xCA, 0x1E, 0x9B, 0x57, 0x3C, 0xFD, 0xD4, 0xE0, 0x16,
    0x67, 0x42, 0x6F, 0x18, 0x8A, 0x17, 0xE5, 0x12, 0xBE, 0x4E,
    0xC4, 0xD6, 0xDA, 0x9E, 0xDE, 0x49, 0xA0, 0xFB, 0xF5, 0x8E,
    0xBB, 0x2F, 0xEE, 0x7A, 0xA9, 0x68, 0x79, 0x91, 0x15, 0xB2,
    0x07, 0x3F, 0x94, 0xC2, 0x10, 0x89, 0x0B, 0x22, 0x5F, 0x21,
    0x80, 0x7F, 0x5D, 0x9A, 0x5A, 0x90, 0x32, 0x27, 0x35, 0x3E,
    0xCC, 0xE7, 0xBF, 0xF7, 0x97, 0x03, 0xFF, 0x19, 0x30, 0xB3,
    0x48, 0xA5, 0xB5, 0xD1, 0xD7, 0x5E, 0x92, 0x2A, 0xAC, 0x56,
    0xAA, 0xC6, 0x4F, 0xB8, 0x38, 0xD2, 0x96, 0xA4, 0x7D, 0xB6,
    0x76, 0xFC, 0x6B, 0xE2, 0x9C, 0x74, 0x04, 0xF1, 0x45, 0x9D,
    0x70, 0x59, 0x64, 0x71, 0x87, 0x20, 0x86, 0x5B, 0xCF, 0x65,
    0xE6, 0x2D, 0xA8, 0x02, 0x1B, 0x60, 0x25, 0xAD, 0xAE, 0xB0,
    0xB9, 0xF6, 0x1C, 0x46, 0x61, 0x69, 0x34, 0x40, 0x7E, 0x0F,
    0x55, 0x47, 0xA3, 0x23, 0xDD, 0x51, 0xAF, 0x3A, 0xC3, 0x5C,
    0xF9, 0xCE, 0xBA, 0xC5, 0xEA, 0x26, 0x2C, 0x53, 0x0D, 0x6E,
    0x85, 0x28, 0x84, 0x09, 0xD3, 0xDF, 0xCD, 0xF4, 0x41, 0x81,
    0x4D, 0x52, 0x6A, 0xDC, 0x37, 0xC8, 0x6C, 0xC1, 0xAB, 0xFA,
    0x24, 0xE1, 0x7B, 0x08, 0x0C, 0xBD, 0xB1, 0x4A, 0x78, 0x88,
    0x95, 0x8B, 0xE3, 0x63, 0xE8, 0x6D, 0xE9, 0xCB, 0xD5, 0xFE,
    0x3B, 0x00, 0x1D, 0x39, 0xF2, 0xEF, 0xB7, 0x0E, 0x66, 0x58,
    0xD0, 0xE4, 0xA6, 0x77, 0x72, 0xF8, 0xEB, 0x75, 0x4B, 0x0A,
    0x31, 0x44, 0x50, 0xB4, 0x8F, 0xED, 0x1F, 0x1A, 0xDB, 0x99,
    0x8D, 0x33, 0x9F, 0x11, 0x83, 0x14
};

void mbedtls_md2_init(mbedtls_md2_context *ctx) {
    memset(ctx, 0, sizeof(mbedtls_md2_context));
}

void mbedtls_md2_free(mbedtls_md2_context *ctx) {
    if (ctx == NULL)
        return;

    mbedtls_platform_zeroize(ctx, sizeof(mbedtls_md2_context));
}

void mbedtls_md2_clone(mbedtls_md2_context *dst,
                       const mbedtls_md2_context *src) {
    *dst = *src;
}

/*
 * MD2 context setup
 */
int mbedtls_md2_starts_ret(mbedtls_md2_context *ctx) {
    memset(ctx->cksum, 0, 16);
    memset(ctx->state, 0, 46);
    memset(ctx->buffer, 0, 16);
    ctx->left = 0;

    return (0);
}

#if !defined(MBEDTLS_DEPRECATED_REMOVED)
void mbedtls_md2_starts(mbedtls_md2_context *ctx) {
    mbedtls_md2_starts_ret(ctx);
}
#endif

#if !defined(MBEDTLS_MD2_PROCESS_ALT)
int mbedtls_internal_md2_process(mbedtls_md2_context *ctx) {
    int i, j;
    unsigned char t = 0;

    for (i = 0; i < 16; i++) {
        ctx->state[i + 16] = ctx->buffer[i];
        ctx->state[i + 32] =
            (unsigned char)(ctx->buffer[i] ^ ctx->state[i]);
    }

    for (i = 0; i < 18; i++) {
        for (j = 0; j < 48; j++) {
            ctx->state[j] = (unsigned char)
                            (ctx->state[j] ^ PI_SUBST[t]);
            t  = ctx->state[j];
        }

        t = (unsigned char)(t + i);
    }

    t = ctx->cksum[15];

    for (i = 0; i < 16; i++) {
        ctx->cksum[i] = (unsigned char)
                        (ctx->cksum[i] ^ PI_SUBST[ctx->buffer[i] ^ t]);
        t  = ctx->cksum[i];
    }

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

    return (0);
}

#if !defined(MBEDTLS_DEPRECATED_REMOVED)
void mbedtls_md2_process(mbedtls_md2_context *ctx) {
    mbedtls_internal_md2_process(ctx);
}
#endif
#endif /* !MBEDTLS_MD2_PROCESS_ALT */

/*
 * MD2 process buffer
 */
int mbedtls_md2_update_ret(mbedtls_md2_context *ctx,
                           const unsigned char *input,
                           size_t ilen) {
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    size_t fill;

    while (ilen > 0) {
        if (ilen > 16 - ctx->left)
            fill = 16 - ctx->left;
        else
            fill = ilen;

        memcpy(ctx->buffer + ctx->left, input, fill);

        ctx->left += fill;
        input += fill;
        ilen  -= fill;

        if (ctx->left == 16) {
            ctx->left = 0;
            if ((ret = mbedtls_internal_md2_process(ctx)) != 0)
                return (ret);
        }
    }

    return (0);
}

#if !defined(MBEDTLS_DEPRECATED_REMOVED)
void mbedtls_md2_update(mbedtls_md2_context *ctx,
                        const unsigned char *input,
                        size_t ilen) {
    mbedtls_md2_update_ret(ctx, input, ilen);
}
#endif

/*
 * MD2 final digest
 */
int mbedtls_md2_finish_ret(mbedtls_md2_context *ctx,
                           unsigned char output[16]) {
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    size_t i;
    unsigned char x;

    x = (unsigned char)(16 - ctx->left);

    for (i = ctx->left; i < 16; i++)
        ctx->buffer[i] = x;

    if ((ret = mbedtls_internal_md2_process(ctx)) != 0)
        return (ret);

    memcpy(ctx->buffer, ctx->cksum, 16);
    if ((ret = mbedtls_internal_md2_process(ctx)) != 0)
        return (ret);

    memcpy(output, ctx->state, 16);

    return (0);
}

#if !defined(MBEDTLS_DEPRECATED_REMOVED)
void mbedtls_md2_finish(mbedtls_md2_context *ctx,
                        unsigned char output[16]) {
    mbedtls_md2_finish_ret(ctx, output);
}
#endif

#endif /* !MBEDTLS_MD2_ALT */

/*
 * output = MD2( input buffer )
 */
int mbedtls_md2_ret(const unsigned char *input,
                    size_t ilen,
                    unsigned char output[16]) {
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    mbedtls_md2_context ctx;

    mbedtls_md2_init(&ctx);

    if ((ret = mbedtls_md2_starts_ret(&ctx)) != 0)
        goto exit;

    if ((ret = mbedtls_md2_update_ret(&ctx, input, ilen)) != 0)
        goto exit;

    if ((ret = mbedtls_md2_finish_ret(&ctx, output)) != 0)
        goto exit;

exit:
    mbedtls_md2_free(&ctx);

    return (ret);
}

#if !defined(MBEDTLS_DEPRECATED_REMOVED)
void mbedtls_md2(const unsigned char *input,
                 size_t ilen,
                 unsigned char output[16]) {
    mbedtls_md2_ret(input, ilen, output);
}
#endif

#if defined(MBEDTLS_SELF_TEST)

/*
 * RFC 1319 test vectors
 */
static const unsigned char md2_test_str[7][81] = {
    { "" },
    { "a" },
    { "abc" },
    { "message digest" },
    { "abcdefghijklmnopqrstuvwxyz" },
    { "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" },
    { "12345678901234567890123456789012345678901234567890123456789012345678901234567890" }
};

static const size_t md2_test_strlen[7] = {
    0, 1, 3, 14, 26, 62, 80
};

static const unsigned char md2_test_sum[7][16] = {
    {
        0x83, 0x50, 0xE5, 0xA3, 0xE2, 0x4C, 0x15, 0x3D,
        0xF2, 0x27, 0x5C, 0x9F, 0x80, 0x69, 0x27, 0x73
    },
    {
        0x32, 0xEC, 0x01, 0xEC, 0x4A, 0x6D, 0xAC, 0x72,
        0xC0, 0xAB, 0x96, 0xFB, 0x34, 0xC0, 0xB5, 0xD1
    },
    {
        0xDA, 0x85, 0x3B, 0x0D, 0x3F, 0x88, 0xD9, 0x9B,
        0x30, 0x28, 0x3A, 0x69, 0xE6, 0xDE, 0xD6, 0xBB
    },
    {
        0xAB, 0x4F, 0x49, 0x6B, 0xFB, 0x2A, 0x53, 0x0B,
        0x21, 0x9F, 0xF3, 0x30, 0x31, 0xFE, 0x06, 0xB0
    },
    {
        0x4E, 0x8D, 0xDF, 0xF3, 0x65, 0x02, 0x92, 0xAB,
        0x5A, 0x41, 0x08, 0xC3, 0xAA, 0x47, 0x94, 0x0B
    },
    {
        0xDA, 0x33, 0xDE, 0xF2, 0xA4, 0x2D, 0xF1, 0x39,
        0x75, 0x35, 0x28, 0x46, 0xC3, 0x03, 0x38, 0xCD
    },
    {
        0xD5, 0x97, 0x6F, 0x79, 0xD8, 0x3D, 0x3A, 0x0D,
        0xC9, 0x80, 0x6C, 0x3C, 0x66, 0xF3, 0xEF, 0xD8
    }
};

/*
 * Checkup routine
 */
int mbedtls_md2_self_test(int verbose) {
    int i, ret = 0;
    unsigned char md2sum[16];

    for (i = 0; i < 7; i++) {
        if (verbose != 0)
            mbedtls_printf("  MD2 test #%d: ", i + 1);

        ret = mbedtls_md2_ret(md2_test_str[i], md2_test_strlen[i], md2sum);
        if (ret != 0)
            goto fail;

        if (memcmp(md2sum, md2_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_MD2_C */