/*

 * MD4 (RFC-1320) message digest.

 * Modified from MD5 code by Andrey Panin <pazke@donpac.ru>

 *

 * Written by Solar Designer <solar@openwall.com> in 2001, and placed in

 * the public domain.  There's absolutely no warranty.

 *

 * This differs from Colin Plumb's older public domain implementation in

 * that no 32-bit integer data type is required, there's no compile-time

 * endianness configuration, and the function prototypes match OpenSSL's.

 * The primary goals are portability and ease of use.

 *

 * This implementation is meant to be fast, but not as fast as possible.

 * Some known optimizations are not included to reduce source code size

 * and avoid compile-time configuration.

 */

#include "md4.h"

#include <string.h>

QT_BEGIN_NAMESPACE

/*

 * The basic MD4 functions.

 */

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

#define G(x, y, z)	(((x) & (y)) | ((x) & (z)) | ((y) & (z)))

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

/*

 * The MD4 transformation for all four rounds.

 */

#define STEP(f, a, b, c, d, x, s) \

	(a) += f((b), (c), (d)) + (x);	 \

	(a) = ((a) << (s)) | ((a) >> (32 - (s)))

/*

 * SET reads 4 input bytes in little-endian byte order and stores them

 * in a properly aligned word in host byte order.

 *

 * The check for little-endian architectures which tolerate unaligned

 * memory accesses is just an optimization.  Nothing will break if it

 * doesn't work.

 */

#if defined(__i386__) || defined(__x86_64__)

#define SET(n) \

	(*(const quint32 *)&ptr[(n) * 4])

#define GET(n) \

	SET(n)

#else

#define SET(n) \

	(ctx->block[(n)] = \

	(quint32)ptr[(n) * 4] | \

	((quint32)ptr[(n) * 4 + 1] << 8) | \

	((quint32)ptr[(n) * 4 + 2] << 16) | \

	((quint32)ptr[(n) * 4 + 3] << 24))

#define GET(n) \

	(ctx->block[(n)])

#endif

/*

 * This processes one or more 64-byte data blocks, but does NOT update

 * the bit counters.  There're no alignment requirements.

 */

static const unsigned char *body(struct md4_context *ctx, const unsigned char *data, size_t size)

{

	const unsigned char *ptr;

	quint32 a, b, c, d;

	quint32 saved_a, saved_b, saved_c, saved_d;

	ptr = data;

	a = ctx->a;

	b = ctx->b;

	c = ctx->c;

	d = ctx->d;

	do {

		saved_a = a;

		saved_b = b;

		saved_c = c;

		saved_d = d;

/* Round 1 */

		STEP(F, a, b, c, d, SET( 0),  3);

		STEP(F, d, a, b, c, SET( 1),  7);

		STEP(F, c, d, a, b, SET( 2), 11);

		STEP(F, b, c, d, a, SET( 3), 19);

		STEP(F, a, b, c, d, SET( 4),  3);

		STEP(F, d, a, b, c, SET( 5),  7);

		STEP(F, c, d, a, b, SET( 6), 11);

		STEP(F, b, c, d, a, SET( 7), 19);

		STEP(F, a, b, c, d, SET( 8),  3);

		STEP(F, d, a, b, c, SET( 9),  7);

		STEP(F, c, d, a, b, SET(10), 11);

		STEP(F, b, c, d, a, SET(11), 19);

		STEP(F, a, b, c, d, SET(12),  3);

		STEP(F, d, a, b, c, SET(13),  7);

		STEP(F, c, d, a, b, SET(14), 11);

		STEP(F, b, c, d, a, SET(15), 19);

/* Round 2 */

		STEP(G, a, b, c, d, GET( 0) + 0x5A827999,  3);

		STEP(G, d, a, b, c, GET( 4) + 0x5A827999,  5);

		STEP(G, c, d, a, b, GET( 8) + 0x5A827999,  9);

		STEP(G, b, c, d, a, GET(12) + 0x5A827999, 13);

		STEP(G, a, b, c, d, GET( 1) + 0x5A827999,  3);

		STEP(G, d, a, b, c, GET( 5) + 0x5A827999,  5);

		STEP(G, c, d, a, b, GET( 9) + 0x5A827999,  9);

		STEP(G, b, c, d, a, GET(13) + 0x5A827999, 13);

		STEP(G, a, b, c, d, GET( 2) + 0x5A827999,  3);

		STEP(G, d, a, b, c, GET( 6) + 0x5A827999,  5);

		STEP(G, c, d, a, b, GET(10) + 0x5A827999,  9);

		STEP(G, b, c, d, a, GET(14) + 0x5A827999, 13);

		STEP(G, a, b, c, d, GET( 3) + 0x5A827999,  3);

		STEP(G, d, a, b, c, GET( 7) + 0x5A827999,  5);

		STEP(G, c, d, a, b, GET(11) + 0x5A827999,  9);

		STEP(G, b, c, d, a, GET(15) + 0x5A827999, 13);

/* Round 3 */

		STEP(H, a, b, c, d, GET( 0) + 0x6ED9EBA1,  3);

		STEP(H, d, a, b, c, GET( 8) + 0x6ED9EBA1,  9);

		STEP(H, c, d, a, b, GET( 4) + 0x6ED9EBA1, 11);

		STEP(H, b, c, d, a, GET(12) + 0x6ED9EBA1, 15);

		STEP(H, a, b, c, d, GET( 2) + 0x6ED9EBA1,  3);

		STEP(H, d, a, b, c, GET(10) + 0x6ED9EBA1,  9);

		STEP(H, c, d, a, b, GET( 6) + 0x6ED9EBA1, 11);

		STEP(H, b, c, d, a, GET(14) + 0x6ED9EBA1, 15);

		STEP(H, a, b, c, d, GET( 1) + 0x6ED9EBA1,  3);

		STEP(H, d, a, b, c, GET( 9) + 0x6ED9EBA1,  9);

		STEP(H, c, d, a, b, GET( 5) + 0x6ED9EBA1, 11);

		STEP(H, b, c, d, a, GET(13) + 0x6ED9EBA1, 15);

		STEP(H, a, b, c, d, GET( 3) + 0x6ED9EBA1,  3);

		STEP(H, d, a, b, c, GET(11) + 0x6ED9EBA1,  9);

		STEP(H, c, d, a, b, GET( 7) + 0x6ED9EBA1, 11);

		STEP(H, b, c, d, a, GET(15) + 0x6ED9EBA1, 15);

		a += saved_a;

		b += saved_b;

		c += saved_c;

		d += saved_d;

		ptr += 64;

	} while (size -= 64);

	ctx->a = a;

	ctx->b = b;

	ctx->c = c;

	ctx->d = d;

	return ptr;

}

static void md4_init(struct md4_context *ctx)

{

	ctx->a = 0x67452301;

	ctx->b = 0xefcdab89;

	ctx->c = 0x98badcfe;

	ctx->d = 0x10325476;

	ctx->lo = 0;

	ctx->hi = 0;

}

static void md4_update(struct md4_context *ctx, const unsigned char *data, size_t size)

{

	/* @UNSAFE */

	quint32 saved_lo;

	unsigned long used, free;

	saved_lo = ctx->lo;

	if ((ctx->lo = (saved_lo + size) & 0x1fffffff) < saved_lo)

		ctx->hi++;

	ctx->hi += size >> 29;

	used = saved_lo & 0x3f;

	if (used) {

		free = 64 - used;

		if (size < free) {

			memcpy(&ctx->buffer[used], data, size);

			return;

		}

		memcpy(&ctx->buffer[used], data, free);

		data = (const unsigned char *) data + free;

		size -= free;

		body(ctx, ctx->buffer, 64);

	}

	if (size >= 64) {

		data = body(ctx, data, size & ~(unsigned long)0x3f);

		size &= 0x3f;

	}

	memcpy(ctx->buffer, data, size);

}

static void md4_final(struct md4_context *ctx, unsigned char result[MD4_RESULTLEN])

{

	/* @UNSAFE */

	unsigned long used, free;

	used = ctx->lo & 0x3f;

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

	free = 64 - used;

	if (free < 8) {

		memset(&ctx->buffer[used], 0, free);

		body(ctx, ctx->buffer, 64);

		used = 0;

		free = 64;

	}

	memset(&ctx->buffer[used], 0, free - 8);

	ctx->lo <<= 3;

	ctx->buffer[56] = ctx->lo;

	ctx->buffer[57] = ctx->lo >> 8;

	ctx->buffer[58] = ctx->lo >> 16;

	ctx->buffer[59] = ctx->lo >> 24;

	ctx->buffer[60] = ctx->hi;

	ctx->buffer[61] = ctx->hi >> 8;

	ctx->buffer[62] = ctx->hi >> 16;

	ctx->buffer[63] = ctx->hi >> 24;

	body(ctx, ctx->buffer, 64);

	result[0] = ctx->a;

	result[1] = ctx->a >> 8;

	result[2] = ctx->a >> 16;

	result[3] = ctx->a >> 24;

	result[4] = ctx->b;

	result[5] = ctx->b >> 8;

	result[6] = ctx->b >> 16;

	result[7] = ctx->b >> 24;

	result[8] = ctx->c;

	result[9] = ctx->c >> 8;

	result[10] = ctx->c >> 16;

	result[11] = ctx->c >> 24;

	result[12] = ctx->d;

	result[13] = ctx->d >> 8;

	result[14] = ctx->d >> 16;

	result[15] = ctx->d >> 24;

	memset(ctx, 0, sizeof(*ctx));

}

#undef F

#undef G

#undef H

QT_END_NAMESPACE