/*
 *  RFC 1321 compliant MD5 implementation
 *
 *  Copyright (C) 2006-2007  Christophe Devine
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License, version 2.1 as published by the Free Software Foundation.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 *  MA  02110-1301  USA
 */
/*
 *  The MD5 algorithm was designed by Ron Rivest in 1991.
 *  From the XYSSL project.
 *
 *  http://www.ietf.org/rfc/rfc1321.txt
 */
#include "md5.h"

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

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

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

/*
 * 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;
}

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

	GET_ULONG_LE(X[0], data, 0);
	GET_ULONG_LE(X[1], data, 4);
	GET_ULONG_LE(X[2], data, 8);
	GET_ULONG_LE(X[3], data, 12);
	GET_ULONG_LE(X[4], data, 16);
	GET_ULONG_LE(X[5], data, 20);
	GET_ULONG_LE(X[6], data, 24);
	GET_ULONG_LE(X[7], data, 28);
	GET_ULONG_LE(X[8], data, 32);
	GET_ULONG_LE(X[9], data, 36);
	GET_ULONG_LE(X[10], data, 40);
	GET_ULONG_LE(X[11], data, 44);
	GET_ULONG_LE(X[12], data, 48);
	GET_ULONG_LE(X[13], data, 52);
	GET_ULONG_LE(X[14], data, 56);
	GET_ULONG_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, unsigned char *input, int ilen)
{
	int fill;
	unsigned long left;

	if (ilen <= 0)
		return;

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

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

	if (ctx->total[0] < (unsigned long) ilen)
		ctx->total[1]++;

	if (left && ilen >= fill) {
		memcpy((void *) (ctx->buffer + left), (void *) 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), (void *) 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])
{
	unsigned long last, padn;
	unsigned long high, low;
	unsigned char msglen[8];

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

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

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

	md5_update(ctx, (unsigned char *) md5_padding, padn);
	md5_update(ctx, msglen, 8);

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

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

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

	memset(&ctx, 0, sizeof(md5_context));
}

/*
 * output = MD5( file contents )
 */
int md5_file(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 (1);

	md5_starts(&ctx);

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

	md5_finish(&ctx, output);

	memset(&ctx, 0, sizeof(md5_context));

	if (ferror(f) != 0) {
		fclose(f);
		return (2);
	}

	fclose(f);
	return (0);
}

/*
 * MD5 HMAC context setup
 */
void md5_hmac_starts(md5_context * ctx, unsigned char *key, int keylen)
{
	int i;
	unsigned char sum[16];

	if (keylen > 64) {
		md5(key, keylen, sum);
		keylen = 16;
		key = sum;
	}

	memset(ctx->ipad, 0x36, 64);
	memset(ctx->opad, 0x5C, 64);

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

	md5_starts(ctx);
	md5_update(ctx, ctx->ipad, 64);

	memset(sum, 0, sizeof(sum));
}

/*
 * MD5 HMAC process buffer
 */
void md5_hmac_update(md5_context * ctx, unsigned char *input, int ilen)
{
	md5_update(ctx, input, ilen);
}

/*
 * MD5 HMAC final digest
 */
void md5_hmac_finish(md5_context * ctx, unsigned char output[16])
{
	unsigned char tmpbuf[16];

	md5_finish(ctx, tmpbuf);
	md5_starts(ctx);
	md5_update(ctx, ctx->opad, 64);
	md5_update(ctx, tmpbuf, 16);
	md5_finish(ctx, output);

	memset(tmpbuf, 0, sizeof(tmpbuf));
}

/*
 * output = HMAC-MD5( hmac key, input buffer )
 */
void md5_hmac(unsigned char *key, int keylen, unsigned char *input,
			  int ilen, unsigned char output[16])
{
	md5_context ctx;

	md5_hmac_starts(&ctx, key, keylen);
	md5_hmac_update(&ctx, input, ilen);
	md5_hmac_finish(&ctx, output);

	memset(&ctx, 0, sizeof(md5_context));
}

#if defined(XYSSL_SELF_TEST)

/*
 * RFC 1321 test vectors
 */
static const char md5_test_str[7][81] = {
	{""},
	{"a"},
	{"abc"},
	{"message digest"},
	{"abcdefghijklmnopqrstuvwxyz"},
	{"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"},
	{"12345678901234567890123456789012345678901234567890123456789012"
	 "345678901234567890"}
};

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)
			printf("  MD5 test #%d: ", i + 1);

		md5((unsigned char *) md5_test_str[i],
			strlen(md5_test_str[i]), md5sum);

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

			return (1);
		}

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

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

	return (0);
}

#endif
