/*
 * Copyright (c) 1995 - 2001 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <afsconfig.h>
#include <afs/param.h>

#include <afs/stds.h>
#include <sys/types.h>
#ifdef AFS_NT40_ENV
#include <winsock2.h>
#else
#include <netinet/in.h>
#endif
#include <string.h>
#include <rx/xdr.h>
#include <rx/rx.h>
#include "rxkad.h"
#include <des.h>
#include "lifetimes.h"
#include "md4.h"
#include "hash.h"

#define A m->counter[0]
#define B m->counter[1]
#define C m->counter[2]
#define D m->counter[3]
#define X data

void
MD4_Init(struct md4 *m)
{
    m->sz[0] = 0;
    m->sz[1] = 0;
    D = 0x10325476;
    C = 0x98badcfe;
    B = 0xefcdab89;
    A = 0x67452301;
}

#define F(x,y,z) CRAYFIX((x & y) | (~x & z))
#define G(x,y,z) ((x & y) | (x & z) | (y & z))
#define H(x,y,z) (x ^ y ^ z)

#define DOIT(a,b,c,d,k,s,i,OP) \
a = cshift(a + OP(b,c,d) + X[k] + i, s)

#define DO1(a,b,c,d,k,s,i) DOIT(a,b,c,d,k,s,i,F)
#define DO2(a,b,c,d,k,s,i) DOIT(a,b,c,d,k,s,i,G)
#define DO3(a,b,c,d,k,s,i) DOIT(a,b,c,d,k,s,i,H)

static inline void
calc(struct md4 *m, afs_uint32 * data)
{
    afs_uint32 AA, BB, CC, DD;

    AA = A;
    BB = B;
    CC = C;
    DD = D;

    /* Round 1 */

    DO1(A, B, C, D, 0, 3, 0);
    DO1(D, A, B, C, 1, 7, 0);
    DO1(C, D, A, B, 2, 11, 0);
    DO1(B, C, D, A, 3, 19, 0);

    DO1(A, B, C, D, 4, 3, 0);
    DO1(D, A, B, C, 5, 7, 0);
    DO1(C, D, A, B, 6, 11, 0);
    DO1(B, C, D, A, 7, 19, 0);

    DO1(A, B, C, D, 8, 3, 0);
    DO1(D, A, B, C, 9, 7, 0);
    DO1(C, D, A, B, 10, 11, 0);
    DO1(B, C, D, A, 11, 19, 0);

    DO1(A, B, C, D, 12, 3, 0);
    DO1(D, A, B, C, 13, 7, 0);
    DO1(C, D, A, B, 14, 11, 0);
    DO1(B, C, D, A, 15, 19, 0);

    /* Round 2 */

    DO2(A, B, C, D, 0, 3, 0x5A827999);
    DO2(D, A, B, C, 4, 5, 0x5A827999);
    DO2(C, D, A, B, 8, 9, 0x5A827999);
    DO2(B, C, D, A, 12, 13, 0x5A827999);

    DO2(A, B, C, D, 1, 3, 0x5A827999);
    DO2(D, A, B, C, 5, 5, 0x5A827999);
    DO2(C, D, A, B, 9, 9, 0x5A827999);
    DO2(B, C, D, A, 13, 13, 0x5A827999);

    DO2(A, B, C, D, 2, 3, 0x5A827999);
    DO2(D, A, B, C, 6, 5, 0x5A827999);
    DO2(C, D, A, B, 10, 9, 0x5A827999);
    DO2(B, C, D, A, 14, 13, 0x5A827999);

    DO2(A, B, C, D, 3, 3, 0x5A827999);
    DO2(D, A, B, C, 7, 5, 0x5A827999);
    DO2(C, D, A, B, 11, 9, 0x5A827999);
    DO2(B, C, D, A, 15, 13, 0x5A827999);

    /* Round 3 */

    DO3(A, B, C, D, 0, 3, 0x6ED9EBA1);
    DO3(D, A, B, C, 8, 9, 0x6ED9EBA1);
    DO3(C, D, A, B, 4, 11, 0x6ED9EBA1);
    DO3(B, C, D, A, 12, 15, 0x6ED9EBA1);

    DO3(A, B, C, D, 2, 3, 0x6ED9EBA1);
    DO3(D, A, B, C, 10, 9, 0x6ED9EBA1);
    DO3(C, D, A, B, 6, 11, 0x6ED9EBA1);
    DO3(B, C, D, A, 14, 15, 0x6ED9EBA1);

    DO3(A, B, C, D, 1, 3, 0x6ED9EBA1);
    DO3(D, A, B, C, 9, 9, 0x6ED9EBA1);
    DO3(C, D, A, B, 5, 11, 0x6ED9EBA1);
    DO3(B, C, D, A, 13, 15, 0x6ED9EBA1);

    DO3(A, B, C, D, 3, 3, 0x6ED9EBA1);
    DO3(D, A, B, C, 11, 9, 0x6ED9EBA1);
    DO3(C, D, A, B, 7, 11, 0x6ED9EBA1);
    DO3(B, C, D, A, 15, 15, 0x6ED9EBA1);

    A += AA;
    B += BB;
    C += CC;
    D += DD;
}

/*
 * From `Performance analysis of MD5' by Joseph D. Touch <touch@isi.edu>
 */

#if defined(WORDS_BIGENDIAN)
static inline afs_uint32
swap_afs_uint32(afs_uint32 t)
{
    afs_uint32 temp1, temp2;

    temp1 = cshift(t, 16);
    temp2 = temp1 >> 8;
    temp1 &= 0x00ff00ff;
    temp2 &= 0x00ff00ff;
    temp1 <<= 8;
    return temp1 | temp2;
}
#endif

struct x32 {
    unsigned int a:32;
    unsigned int b:32;
};

void
MD4_Update(struct md4 *m, const void *v, size_t len)
{
    const unsigned char *p = v;
    size_t old_sz = m->sz[0];
    size_t offset;

    m->sz[0] += len * 8;
    if (m->sz[0] < old_sz)
	++m->sz[1];
    offset = (old_sz / 8) % 64;
    while (len > 0) {
	size_t l = min(len, 64 - offset);
	memcpy(m->save + offset, p, l);
	offset += l;
	p += l;
	len -= l;
	if (offset == 64) {
#if defined(WORDS_BIGENDIAN)
	    int i;
	    afs_uint32 current[16];
	    struct x32 *u = (struct x32 *)m->save;
	    for (i = 0; i < 8; i++) {
		current[2 * i + 0] = swap_afs_uint32(u[i].a);
		current[2 * i + 1] = swap_afs_uint32(u[i].b);
	    }
	    calc(m, current);
#else
	    calc(m, (afs_uint32 *) m->save);
#endif
	    offset = 0;
	}
    }
}

void
MD4_Final(void *res, struct md4 *m)
{
    static unsigned char zeros[72];
    unsigned offset = (m->sz[0] / 8) % 64;
    unsigned int dstart = (120 - offset - 1) % 64 + 1;

    *zeros = 0x80;
    memset(zeros + 1, 0, sizeof(zeros) - 1);
    zeros[dstart + 0] = (m->sz[0] >> 0) & 0xff;
    zeros[dstart + 1] = (m->sz[0] >> 8) & 0xff;
    zeros[dstart + 2] = (m->sz[0] >> 16) & 0xff;
    zeros[dstart + 3] = (m->sz[0] >> 24) & 0xff;
    zeros[dstart + 4] = (m->sz[1] >> 0) & 0xff;
    zeros[dstart + 5] = (m->sz[1] >> 8) & 0xff;
    zeros[dstart + 6] = (m->sz[1] >> 16) & 0xff;
    zeros[dstart + 7] = (m->sz[1] >> 24) & 0xff;
    MD4_Update(m, zeros, dstart + 8);
    {
	int i;
	unsigned char *r = (unsigned char *)res;

	for (i = 0; i < 4; ++i) {
	    r[4 * i] = m->counter[i] & 0xFF;
	    r[4 * i + 1] = (m->counter[i] >> 8) & 0xFF;
	    r[4 * i + 2] = (m->counter[i] >> 16) & 0xFF;
	    r[4 * i + 3] = (m->counter[i] >> 24) & 0xFF;
	}
    }
#if 0
    {
	int i;
	afs_uint32 *r = (afs_uint32 *) res;

	for (i = 0; i < 4; ++i)
	    r[i] = swap_afs_uint32(m->counter[i]);
    }
#endif
}
