// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// 64-bit MD5 (does full MD5 but returns 64 bits only).
// Translation of ../../pkg/crypto/md5/md5*.go.
#include <u.h>
#include <libc.h>
#include "go.h"
#include "md5.h"
static int md5block(MD5 *dig, uchar *p, int nn);
enum {
_Chunk = 64
};
#define _Init0 0x67452301
#define _Init1 0xEFCDAB89
#define _Init2 0x98BADCFE
#define _Init3 0x10325476
void
md5reset(MD5 *d)
{
d->s[0] = _Init0;
d->s[1] = _Init1;
d->s[2] = _Init2;
d->s[3] = _Init3;
d->nx = 0;
d->len = 0;
}
void
md5write(MD5 *d, uchar *p, int nn)
{
int i, n;
d->len += nn;
if(d->nx > 0) {
n = nn;
if(n > _Chunk - d->nx)
n = _Chunk - d->nx;
for(i=0; i<n; i++)
d->x[d->nx+i] = p[i];
d->nx += n;
if(d->nx == _Chunk) {
md5block(d, d->x, _Chunk);
d->nx = 0;
}
p += n;
nn -= n;
}
n = md5block(d, p, nn);
p += n;
nn -= n;
if(nn > 0) {
for(i=0; i<nn; i++)
d->x[i] = p[i];
d->nx = nn;
}
}
uint64
md5sum(MD5 *d, uint64 *hi)
{
uchar tmp[64];
int i;
uint64 len;
// Padding. Add a 1 bit and 0 bits until 56 bytes mod 64.
len = d->len;
memset(tmp, 0, sizeof tmp);
tmp[0] = 0x80;
if(len%64 < 56)
md5write(d, tmp, 56-len%64);
else
md5write(d, tmp, 64+56-len%64);
// Length in bits.
len <<= 3;
for(i=0; i<8; i++)
tmp[i] = len>>(8*i);
md5write(d, tmp, 8);
if(d->nx != 0)
fatal("md5sum");
if(hi != nil)
*hi = d->s[2] | ((uint64)d->s[3]<<32);
return d->s[0] | ((uint64)d->s[1]<<32);
}
// MD5 block step.
// In its own file so that a faster assembly or C version
// can be substituted easily.
// table[i] = int((1<<32) * abs(sin(i+1 radians))).
static uint32 table[64] = {
// round 1
0xd76aa478,
0xe8c7b756,
0x242070db,
0xc1bdceee,
0xf57c0faf,
0x4787c62a,
0xa8304613,
0xfd469501,
0x698098d8,
0x8b44f7af,
0xffff5bb1,
0x895cd7be,
0x6b901122,
0xfd987193,
0xa679438e,
0x49b40821,
// round 2
0xf61e2562,
0xc040b340,
0x265e5a51,
0xe9b6c7aa,
0xd62f105d,
0x2441453,
0xd8a1e681,
0xe7d3fbc8,
0x21e1cde6,
0xc33707d6,
0xf4d50d87,
0x455a14ed,
0xa9e3e905,
0xfcefa3f8,
0x676f02d9,
0x8d2a4c8a,
// round3
0xfffa3942,
0x8771f681,
0x6d9d6122,
0xfde5380c,
0xa4beea44,
0x4bdecfa9,
0xf6bb4b60,
0xbebfbc70,
0x289b7ec6,
0xeaa127fa,
0xd4ef3085,
0x4881d05,
0xd9d4d039,
0xe6db99e5,
0x1fa27cf8,
0xc4ac5665,
// round 4
0xf4292244,
0x432aff97,
0xab9423a7,
0xfc93a039,
0x655b59c3,
0x8f0ccc92,
0xffeff47d,
0x85845dd1,
0x6fa87e4f,
0xfe2ce6e0,
0xa3014314,
0x4e0811a1,
0xf7537e82,
0xbd3af235,
0x2ad7d2bb,
0xeb86d391,
};
static uint32 shift1[] = { 7, 12, 17, 22 };
static uint32 shift2[] = { 5, 9, 14, 20 };
static uint32 shift3[] = { 4, 11, 16, 23 };
static uint32 shift4[] = { 6, 10, 15, 21 };
static int
md5block(MD5 *dig, uchar *p, int nn)
{
uint32 a, b, c, d, aa, bb, cc, dd;
int i, j, n;
uint32 X[16];
a = dig->s[0];
b = dig->s[1];
c = dig->s[2];
d = dig->s[3];
n = 0;
while(nn >= _Chunk) {
aa = a;
bb = b;
cc = c;
dd = d;
for(i=0; i<16; i++) {
j = i*4;
X[i] = p[j] | (p[j+1]<<8) | (p[j+2]<<16) | ((uint32)p[j+3]<<24);
}
// Round 1.
for(i=0; i<16; i++) {
uint32 x, t, s, f;
x = i;
t = i;
s = shift1[i%4];
f = ((c ^ d) & b) ^ d;
a += f + X[x] + table[t];
a = a<<s | a>>(32-s);
a += b;
t = d;
d = c;
c = b;
b = a;
a = t;
}
// Round 2.
for(i=0; i<16; i++) {
uint32 x, t, s, g;
x = (1+5*i)%16;
t = 16+i;
s = shift2[i%4];
g = ((b ^ c) & d) ^ c;
a += g + X[x] + table[t];
a = a<<s | a>>(32-s);
a += b;
t = d;
d = c;
c = b;
b = a;
a = t;
}
// Round 3.
for(i=0; i<16; i++) {
uint32 x, t, s, h;
x = (5+3*i)%16;
t = 32+i;
s = shift3[i%4];
h = b ^ c ^ d;
a += h + X[x] + table[t];
a = a<<s | a>>(32-s);
a += b;
t = d;
d = c;
c = b;
b = a;
a = t;
}
// Round 4.
for(i=0; i<16; i++) {
uint32 x, s, t, ii;
x = (7*i)%16;
s = shift4[i%4];
t = 48+i;
ii = c ^ (b | ~d);
a += ii + X[x] + table[t];
a = a<<s | a>>(32-s);
a += b;
t = d;
d = c;
c = b;
b = a;
a = t;
}
a += aa;
b += bb;
c += cc;
d += dd;
p += _Chunk;
n += _Chunk;
nn -= _Chunk;
}
dig->s[0] = a;
dig->s[1] = b;
dig->s[2] = c;
dig->s[3] = d;
return n;
}