mirror of
https://github.com/michaelrsweet/pdfio.git
synced 2024-12-27 05:48:20 +01:00
339 lines
9.5 KiB
C
339 lines
9.5 KiB
C
//
|
||
// MD5 functions for PDFio.
|
||
//
|
||
// Copyright © 2021 by Michael R Sweet.
|
||
// Copyright © 1999 Aladdin Enterprises. All rights reserved.
|
||
//
|
||
// This software is provided 'as-is', without any express or implied
|
||
// warranty. In no event will the authors be held liable for any damages
|
||
// arising from the use of this software.
|
||
//
|
||
// Permission is granted to anyone to use this software for any purpose,
|
||
// including commercial applications, and to alter it and redistribute it
|
||
// freely, subject to the following restrictions:
|
||
//
|
||
// 1. The origin of this software must not be misrepresented; you must not
|
||
// claim that you wrote the original software. If you use this software
|
||
// in a product, an acknowledgment in the product documentation would be
|
||
// appreciated but is not required.
|
||
// 2. Altered source versions must be plainly marked as such, and must not be
|
||
// misrepresented as being the original software.
|
||
// 3. This notice may not be removed or altered from any source distribution.
|
||
//
|
||
// L. Peter Deutsch
|
||
// ghost@aladdin.com
|
||
//
|
||
|
||
#include "pdfio-private.h"
|
||
|
||
|
||
/*
|
||
Independent implementation of MD5 (RFC 1321).
|
||
|
||
This code implements the MD5 Algorithm defined in RFC 1321.
|
||
It is derived directly from the text of the RFC and not from the
|
||
reference implementation.
|
||
|
||
The original and principal author of md5.c is L. Peter Deutsch
|
||
<ghost@aladdin.com>. Other authors are noted in the change history
|
||
that follows (in reverse chronological order):
|
||
|
||
1999-11-04 lpd Edited comments slightly for automatic TOC extraction.
|
||
1999-10-18 lpd Fixed typo in header comment (ansi2knr rather than md5).
|
||
1999-05-03 lpd Original version.
|
||
*/
|
||
|
||
#define T1 0xd76aa478
|
||
#define T2 0xe8c7b756
|
||
#define T3 0x242070db
|
||
#define T4 0xc1bdceee
|
||
#define T5 0xf57c0faf
|
||
#define T6 0x4787c62a
|
||
#define T7 0xa8304613
|
||
#define T8 0xfd469501
|
||
#define T9 0x698098d8
|
||
#define T10 0x8b44f7af
|
||
#define T11 0xffff5bb1
|
||
#define T12 0x895cd7be
|
||
#define T13 0x6b901122
|
||
#define T14 0xfd987193
|
||
#define T15 0xa679438e
|
||
#define T16 0x49b40821
|
||
#define T17 0xf61e2562
|
||
#define T18 0xc040b340
|
||
#define T19 0x265e5a51
|
||
#define T20 0xe9b6c7aa
|
||
#define T21 0xd62f105d
|
||
#define T22 0x02441453
|
||
#define T23 0xd8a1e681
|
||
#define T24 0xe7d3fbc8
|
||
#define T25 0x21e1cde6
|
||
#define T26 0xc33707d6
|
||
#define T27 0xf4d50d87
|
||
#define T28 0x455a14ed
|
||
#define T29 0xa9e3e905
|
||
#define T30 0xfcefa3f8
|
||
#define T31 0x676f02d9
|
||
#define T32 0x8d2a4c8a
|
||
#define T33 0xfffa3942
|
||
#define T34 0x8771f681
|
||
#define T35 0x6d9d6122
|
||
#define T36 0xfde5380c
|
||
#define T37 0xa4beea44
|
||
#define T38 0x4bdecfa9
|
||
#define T39 0xf6bb4b60
|
||
#define T40 0xbebfbc70
|
||
#define T41 0x289b7ec6
|
||
#define T42 0xeaa127fa
|
||
#define T43 0xd4ef3085
|
||
#define T44 0x04881d05
|
||
#define T45 0xd9d4d039
|
||
#define T46 0xe6db99e5
|
||
#define T47 0x1fa27cf8
|
||
#define T48 0xc4ac5665
|
||
#define T49 0xf4292244
|
||
#define T50 0x432aff97
|
||
#define T51 0xab9423a7
|
||
#define T52 0xfc93a039
|
||
#define T53 0x655b59c3
|
||
#define T54 0x8f0ccc92
|
||
#define T55 0xffeff47d
|
||
#define T56 0x85845dd1
|
||
#define T57 0x6fa87e4f
|
||
#define T58 0xfe2ce6e0
|
||
#define T59 0xa3014314
|
||
#define T60 0x4e0811a1
|
||
#define T61 0xf7537e82
|
||
#define T62 0xbd3af235
|
||
#define T63 0x2ad7d2bb
|
||
#define T64 0xeb86d391
|
||
|
||
static void
|
||
md5_process(_pdfio_md5_t *pms, const uint8_t *data /*[64]*/)
|
||
{
|
||
uint32_t
|
||
a = pms->abcd[0], b = pms->abcd[1],
|
||
c = pms->abcd[2], d = pms->abcd[3];
|
||
uint32_t t;
|
||
|
||
#ifndef ARCH_IS_BIG_ENDIAN
|
||
# define ARCH_IS_BIG_ENDIAN 1 /* slower, default implementation */
|
||
#endif
|
||
#if ARCH_IS_BIG_ENDIAN
|
||
|
||
/*
|
||
* On big-endian machines, we must arrange the bytes in the right
|
||
* order. (This also works on machines of unknown byte order.)
|
||
*/
|
||
uint32_t X[16];
|
||
const uint8_t *xp = data;
|
||
int i;
|
||
|
||
for (i = 0; i < 16; ++i, xp += 4)
|
||
X[i] = xp[0] + (unsigned)(xp[1] << 8) + (unsigned)(xp[2] << 16) + (unsigned)(xp[3] << 24);
|
||
|
||
#else /* !ARCH_IS_BIG_ENDIAN */
|
||
|
||
/*
|
||
* On little-endian machines, we can process properly aligned data
|
||
* without copying it.
|
||
*/
|
||
uint32_t xbuf[16];
|
||
const uint32_t *X;
|
||
|
||
if (!((data - (const uint8_t *)0) & 3)) {
|
||
/* data are properly aligned */
|
||
X = (const uint32_t *)data;
|
||
} else {
|
||
/* not aligned */
|
||
memcpy(xbuf, data, 64);
|
||
X = xbuf;
|
||
}
|
||
#endif
|
||
|
||
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32 - (n))))
|
||
|
||
/* Round 1. */
|
||
/* Let [abcd k s i] denote the operation
|
||
a = b + ((a + F(b,c,d) + X[k] + T[i]) <<< s). */
|
||
#define F(x, y, z) (((x) & (y)) | (~(x) & (z)))
|
||
#define SET(a, b, c, d, k, s, Ti)\
|
||
t = a + F(b,c,d) + X[k] + Ti;\
|
||
a = ROTATE_LEFT(t, s) + b
|
||
/* Do the following 16 operations. */
|
||
SET(a, b, c, d, 0, 7, T1);
|
||
SET(d, a, b, c, 1, 12, T2);
|
||
SET(c, d, a, b, 2, 17, T3);
|
||
SET(b, c, d, a, 3, 22, T4);
|
||
SET(a, b, c, d, 4, 7, T5);
|
||
SET(d, a, b, c, 5, 12, T6);
|
||
SET(c, d, a, b, 6, 17, T7);
|
||
SET(b, c, d, a, 7, 22, T8);
|
||
SET(a, b, c, d, 8, 7, T9);
|
||
SET(d, a, b, c, 9, 12, T10);
|
||
SET(c, d, a, b, 10, 17, T11);
|
||
SET(b, c, d, a, 11, 22, T12);
|
||
SET(a, b, c, d, 12, 7, T13);
|
||
SET(d, a, b, c, 13, 12, T14);
|
||
SET(c, d, a, b, 14, 17, T15);
|
||
SET(b, c, d, a, 15, 22, T16);
|
||
#undef SET
|
||
|
||
/* Round 2. */
|
||
/* Let [abcd k s i] denote the operation
|
||
a = b + ((a + G(b,c,d) + X[k] + T[i]) <<< s). */
|
||
#define G(x, y, z) (((x) & (z)) | ((y) & ~(z)))
|
||
#define SET(a, b, c, d, k, s, Ti)\
|
||
t = a + G(b,c,d) + X[k] + Ti;\
|
||
a = ROTATE_LEFT(t, s) + b
|
||
/* Do the following 16 operations. */
|
||
SET(a, b, c, d, 1, 5, T17);
|
||
SET(d, a, b, c, 6, 9, T18);
|
||
SET(c, d, a, b, 11, 14, T19);
|
||
SET(b, c, d, a, 0, 20, T20);
|
||
SET(a, b, c, d, 5, 5, T21);
|
||
SET(d, a, b, c, 10, 9, T22);
|
||
SET(c, d, a, b, 15, 14, T23);
|
||
SET(b, c, d, a, 4, 20, T24);
|
||
SET(a, b, c, d, 9, 5, T25);
|
||
SET(d, a, b, c, 14, 9, T26);
|
||
SET(c, d, a, b, 3, 14, T27);
|
||
SET(b, c, d, a, 8, 20, T28);
|
||
SET(a, b, c, d, 13, 5, T29);
|
||
SET(d, a, b, c, 2, 9, T30);
|
||
SET(c, d, a, b, 7, 14, T31);
|
||
SET(b, c, d, a, 12, 20, T32);
|
||
#undef SET
|
||
|
||
/* Round 3. */
|
||
/* Let [abcd k s t] denote the operation
|
||
a = b + ((a + H(b,c,d) + X[k] + T[i]) <<< s). */
|
||
#define H(x, y, z) ((x) ^ (y) ^ (z))
|
||
#define SET(a, b, c, d, k, s, Ti)\
|
||
t = a + H(b,c,d) + X[k] + Ti;\
|
||
a = ROTATE_LEFT(t, s) + b
|
||
/* Do the following 16 operations. */
|
||
SET(a, b, c, d, 5, 4, T33);
|
||
SET(d, a, b, c, 8, 11, T34);
|
||
SET(c, d, a, b, 11, 16, T35);
|
||
SET(b, c, d, a, 14, 23, T36);
|
||
SET(a, b, c, d, 1, 4, T37);
|
||
SET(d, a, b, c, 4, 11, T38);
|
||
SET(c, d, a, b, 7, 16, T39);
|
||
SET(b, c, d, a, 10, 23, T40);
|
||
SET(a, b, c, d, 13, 4, T41);
|
||
SET(d, a, b, c, 0, 11, T42);
|
||
SET(c, d, a, b, 3, 16, T43);
|
||
SET(b, c, d, a, 6, 23, T44);
|
||
SET(a, b, c, d, 9, 4, T45);
|
||
SET(d, a, b, c, 12, 11, T46);
|
||
SET(c, d, a, b, 15, 16, T47);
|
||
SET(b, c, d, a, 2, 23, T48);
|
||
#undef SET
|
||
|
||
/* Round 4. */
|
||
/* Let [abcd k s t] denote the operation
|
||
a = b + ((a + I(b,c,d) + X[k] + T[i]) <<< s). */
|
||
#define I(x, y, z) ((y) ^ ((x) | ~(z)))
|
||
#define SET(a, b, c, d, k, s, Ti)\
|
||
t = a + I(b,c,d) + X[k] + Ti;\
|
||
a = ROTATE_LEFT(t, s) + b
|
||
/* Do the following 16 operations. */
|
||
SET(a, b, c, d, 0, 6, T49);
|
||
SET(d, a, b, c, 7, 10, T50);
|
||
SET(c, d, a, b, 14, 15, T51);
|
||
SET(b, c, d, a, 5, 21, T52);
|
||
SET(a, b, c, d, 12, 6, T53);
|
||
SET(d, a, b, c, 3, 10, T54);
|
||
SET(c, d, a, b, 10, 15, T55);
|
||
SET(b, c, d, a, 1, 21, T56);
|
||
SET(a, b, c, d, 8, 6, T57);
|
||
SET(d, a, b, c, 15, 10, T58);
|
||
SET(c, d, a, b, 6, 15, T59);
|
||
SET(b, c, d, a, 13, 21, T60);
|
||
SET(a, b, c, d, 4, 6, T61);
|
||
SET(d, a, b, c, 11, 10, T62);
|
||
SET(c, d, a, b, 2, 15, T63);
|
||
SET(b, c, d, a, 9, 21, T64);
|
||
#undef SET
|
||
|
||
/* Then perform the following additions. (That is increment each
|
||
of the four registers by the value it had before this block
|
||
was started.) */
|
||
pms->abcd[0] += a;
|
||
pms->abcd[1] += b;
|
||
pms->abcd[2] += c;
|
||
pms->abcd[3] += d;
|
||
}
|
||
|
||
void
|
||
_pdfioCryptoMD5Init(_pdfio_md5_t *pms)
|
||
{
|
||
pms->count[0] = pms->count[1] = 0;
|
||
pms->abcd[0] = 0x67452301;
|
||
pms->abcd[1] = 0xefcdab89;
|
||
pms->abcd[2] = 0x98badcfe;
|
||
pms->abcd[3] = 0x10325476;
|
||
}
|
||
|
||
void
|
||
_pdfioCryptoMD5Append(_pdfio_md5_t *pms, const uint8_t *data, size_t nbytes)
|
||
{
|
||
const uint8_t *p = data;
|
||
size_t left = nbytes;
|
||
size_t offset = (pms->count[0] >> 3) & 63;
|
||
uint32_t nbits = (uint32_t)(nbytes << 3);
|
||
|
||
if (nbytes == 0)
|
||
return;
|
||
|
||
/* Update the message length. */
|
||
pms->count[1] += (unsigned)(nbytes >> 29);
|
||
pms->count[0] += nbits;
|
||
if (pms->count[0] < nbits)
|
||
pms->count[1]++;
|
||
|
||
/* Process an initial partial block. */
|
||
if (offset) {
|
||
size_t copy = (offset + nbytes > 64 ? 64 - offset : nbytes);
|
||
|
||
memcpy(pms->buf + offset, p, copy);
|
||
if (offset + copy < 64)
|
||
return;
|
||
p += copy;
|
||
left -= copy;
|
||
md5_process(pms, pms->buf);
|
||
}
|
||
|
||
/* Process full blocks. */
|
||
for (; left >= 64; p += 64, left -= 64)
|
||
md5_process(pms, p);
|
||
|
||
/* Process a final partial block. */
|
||
if (left)
|
||
memcpy(pms->buf, p, left);
|
||
}
|
||
|
||
void
|
||
_pdfioCryptoMD5Finish(_pdfio_md5_t *pms, uint8_t digest[16])
|
||
{
|
||
static const uint8_t pad[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
|
||
};
|
||
uint8_t data[8];
|
||
int i;
|
||
|
||
/* Save the length before padding. */
|
||
for (i = 0; i < 8; ++i)
|
||
data[i] = (uint8_t)(pms->count[i >> 2] >> ((i & 3) << 3));
|
||
/* Pad to 56 bytes mod 64. */
|
||
_pdfioCryptoMD5Append(pms, pad, ((55 - (pms->count[0] >> 3)) & 63) + 1);
|
||
/* Append the length. */
|
||
_pdfioCryptoMD5Append(pms, data, 8);
|
||
for (i = 0; i < 16; ++i)
|
||
digest[i] = (uint8_t)(pms->abcd[i >> 2] >> ((i & 3) << 3));
|
||
}
|