ref: e0cb81af9497c322d9656fec0201586f2428aad5
dir: /sys/src/libsec/port/md5block.c/
#include "os.h"
#include <libsec.h>
/*
* rfc1321 requires that I include this. The code is new. The constants
* all come from the rfc (hence the copyright). We trade a table for the
* macros in rfc. The total size is a lot less. -- presotto
*
* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
* rights reserved.
*
* License to copy and use this software is granted provided that it
* is identified as the "RSA Data Security, Inc. MD5 Message-Digest
* Algorithm" in all material mentioning or referencing this software
* or this function.
*
* License is also granted to make and use derivative works provided
* that such works are identified as "derived from the RSA Data
* Security, Inc. MD5 Message-Digest Algorithm" in all material
* mentioning or referencing the derived work.
*
* RSA Data Security, Inc. makes no representations concerning either
* the merchantability of this software or the suitability of this
* software forany particular purpose. It is provided "as is"
* without express or implied warranty of any kind.
* These notices must be retained in any copies of any part of this
* documentation and/or software.
*/
/*
* Rotate ammounts used in the algorithm
*/
enum
{
S11= 7,
S12= 12,
S13= 17,
S14= 22,
S21= 5,
S22= 9,
S23= 14,
S24= 20,
S31= 4,
S32= 11,
S33= 16,
S34= 23,
S41= 6,
S42= 10,
S43= 15,
S44= 21,
};
static u32int md5tab[] =
{
/* round 1 */
/*[0]*/ 0xd76aa478,
0xe8c7b756,
0x242070db,
0xc1bdceee,
0xf57c0faf,
0x4787c62a,
0xa8304613,
0xfd469501,
0x698098d8,
0x8b44f7af,
0xffff5bb1,
0x895cd7be,
0x6b901122,
0xfd987193,
0xa679438e,
0x49b40821,
/* round 2 */
/*[16]*/0xf61e2562,
0xc040b340,
0x265e5a51,
0xe9b6c7aa,
0xd62f105d,
0x2441453,
0xd8a1e681,
0xe7d3fbc8,
0x21e1cde6,
0xc33707d6,
0xf4d50d87,
0x455a14ed,
0xa9e3e905,
0xfcefa3f8,
0x676f02d9,
0x8d2a4c8a,
/* round 3 */
/*[32]*/0xfffa3942,
0x8771f681,
0x6d9d6122,
0xfde5380c,
0xa4beea44,
0x4bdecfa9,
0xf6bb4b60,
0xbebfbc70,
0x289b7ec6,
0xeaa127fa,
0xd4ef3085,
0x4881d05,
0xd9d4d039,
0xe6db99e5,
0x1fa27cf8,
0xc4ac5665,
/* round 4 */
/*[48]*/0xf4292244,
0x432aff97,
0xab9423a7,
0xfc93a039,
0x655b59c3,
0x8f0ccc92,
0xffeff47d,
0x85845dd1,
0x6fa87e4f,
0xfe2ce6e0,
0xa3014314,
0x4e0811a1,
0xf7537e82,
0xbd3af235,
0x2ad7d2bb,
0xeb86d391,
};
static void decode(u32int*, uchar*, ulong);
extern void _md5block(uchar *p, ulong len, u32int *s);
void
_md5block(uchar *p, ulong len, u32int *s)
{
u32int a, b, c, d, sh;
u32int *t;
uchar *end;
u32int x[16];
for(end = p+len; p < end; p += 64){
a = s[0];
b = s[1];
c = s[2];
d = s[3];
decode(x, p, 64);
t = md5tab;
sh = 0;
for(; sh != 16; t += 4){
a += ((c ^ d) & b) ^ d;
a += x[sh] + t[0];
a = (a << S11) | (a >> (32 - S11));
a += b;
d += ((b ^ c) & a) ^ c;
d += x[sh + 1] + t[1];
d = (d << S12) | (d >> (32 - S12));
d += a;
c += ((a ^ b) & d) ^ b;
c += x[sh + 2] + t[2];
c = (c << S13) | (c >> (32 - S13));
c += d;
b += ((d ^ a) & c) ^ a;
b += x[sh + 3] + t[3];
b = (b << S14) | (b >> (32 - S14));
b += c;
sh += 4;
}
sh = 1;
for(; sh != 1+20*4; t += 4){
a += ((b ^ c) & d) ^ c;
a += x[sh & 0xf] + t[0];
a = (a << S21) | (a >> (32 - S21));
a += b;
d += ((a ^ b) & c) ^ b;
d += x[(sh + 5) & 0xf] + t[1];
d = (d << S22) | (d >> (32 - S22));
d += a;
c += ((d ^ a) & b) ^ a;
c += x[(sh + 10) & 0xf] + t[2];
c = (c << S23) | (c >> (32 - S23));
c += d;
b += ((c ^ d) & a) ^ d;
b += x[(sh + 15) & 0xf] + t[3];
b = (b << S24) | (b >> (32 - S24));
b += c;
sh += 20;
}
sh = 5;
for(; sh != 5+12*4; t += 4){
a += b ^ c ^ d;
a += x[sh & 0xf] + t[0];
a = (a << S31) | (a >> (32 - S31));
a += b;
d += a ^ b ^ c;
d += x[(sh + 3) & 0xf] + t[1];
d = (d << S32) | (d >> (32 - S32));
d += a;
c += d ^ a ^ b;
c += x[(sh + 6) & 0xf] + t[2];
c = (c << S33) | (c >> (32 - S33));
c += d;
b += c ^ d ^ a;
b += x[(sh + 9) & 0xf] + t[3];
b = (b << S34) | (b >> (32 - S34));
b += c;
sh += 12;
}
sh = 0;
for(; sh != 28*4; t += 4){
a += c ^ (b | ~d);
a += x[sh & 0xf] + t[0];
a = (a << S41) | (a >> (32 - S41));
a += b;
d += b ^ (a | ~c);
d += x[(sh + 7) & 0xf] + t[1];
d = (d << S42) | (d >> (32 - S42));
d += a;
c += a ^ (d | ~b);
c += x[(sh + 14) & 0xf] + t[2];
c = (c << S43) | (c >> (32 - S43));
c += d;
b += d ^ (c | ~a);
b += x[(sh + 21) & 0xf] + t[3];
b = (b << S44) | (b >> (32 - S44));
b += c;
sh += 28;
}
s[0] += a;
s[1] += b;
s[2] += c;
s[3] += d;
}
}
/*
* decodes input (uchar) into output (u32int). Assumes len is
* a multiple of 4.
*/
static void
decode(u32int *output, uchar *input, ulong len)
{
uchar *e;
for(e = input+len; input < e; input += 4)
*output++ = input[0] | (input[1] << 8) |
(input[2] << 16) | (input[3] << 24);
}