qpdf/libqpdf/MD5_native.cc

308 lines
9.7 KiB
C++

// This file implements a class for computation of MD5 checksums.
// It is derived from the reference algorithm for MD5 as given in
// RFC 1321. The original copyright notice is as follows:
//
/////////////////////////////////////////////////////////////////////////
//
// 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 for any 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.
//
/////////////////////////////////////////////////////////////////////////
#include <qpdf/MD5_native.hh>
#include <qpdf/QUtil.hh>
#include <qpdf/QIntC.hh>
#include <stdio.h>
#include <memory.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
int const S11 = 7;
int const S12 = 12;
int const S13 = 17;
int const S14 = 22;
int const S21 = 5;
int const S22 = 9;
int const S23 = 14;
int const S24 = 20;
int const S31 = 4;
int const S32 = 11;
int const S33 = 16;
int const S34 = 23;
int const S41 = 6;
int const S42 = 10;
int const S43 = 15;
int const S44 = 21;
static unsigned char PADDING[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
};
// F, G, H and I are basic MD5 functions.
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))
// ROTATE_LEFT rotates x left n bits.
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
// FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
// Rotation is separate from addition to prevent recomputation.
#define FF(a, b, c, d, x, s, ac) { \
(a) += F ((b), (c), (d)) + (x) + static_cast<uint32_t>(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
#define GG(a, b, c, d, x, s, ac) { \
(a) += G ((b), (c), (d)) + (x) + static_cast<uint32_t>(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
#define HH(a, b, c, d, x, s, ac) { \
(a) += H ((b), (c), (d)) + (x) + static_cast<uint32_t>(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
#define II(a, b, c, d, x, s, ac) { \
(a) += I ((b), (c), (d)) + (x) + static_cast<uint32_t>(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
MD5_native::MD5_native()
{
init();
}
// MD5 initialization. Begins an MD5 operation, writing a new context.
void MD5_native::init()
{
count[0] = count[1] = 0;
// Load magic initialization constants.
state[0] = 0x67452301;
state[1] = 0xefcdab89;
state[2] = 0x98badcfe;
state[3] = 0x10325476;
finalized = false;
memset(digest_val, 0, sizeof(digest_val));
}
// MD5 block update operation. Continues an MD5 message-digest
// operation, processing another message block, and updating the
// context.
void MD5_native::update(unsigned char *input,
size_t inputLen)
{
unsigned int i, index, partLen;
// Compute number of bytes mod 64
index = static_cast<unsigned int>((count[0] >> 3) & 0x3f);
// Update number of bits
if ((count[0] += (static_cast<uint32_t>(inputLen) << 3)) <
(static_cast<uint32_t>(inputLen) << 3))
count[1]++;
count[1] += (static_cast<uint32_t>(inputLen) >> 29);
partLen = 64 - index;
// Transform as many times as possible.
if (inputLen >= partLen) {
memcpy(&buffer[index], input, partLen);
transform(state, buffer);
for (i = partLen; i + 63 < inputLen; i += 64)
transform(state, &input[i]);
index = 0;
}
else
i = 0;
// Buffer remaining input
memcpy(&buffer[index], &input[i], inputLen-i);
}
// MD5 finalization. Ends an MD5 message-digest operation, writing the
// the message digest and zeroizing the context.
void MD5_native::finalize()
{
if (finalized)
{
return;
}
unsigned char bits[8];
unsigned int index, padLen;
// Save number of bits
encode(bits, count, 8);
// Pad out to 56 mod 64.
index = static_cast<unsigned int>((count[0] >> 3) & 0x3f);
padLen = (index < 56) ? (56 - index) : (120 - index);
update(PADDING, padLen);
// Append length (before padding)
update(bits, 8);
// Store state in digest_val
encode(digest_val, state, 16);
// Zeroize sensitive information.
memset(state, 0, sizeof(state));
memset(count, 0, sizeof(count));
memset(buffer, 0, sizeof(buffer));
finalized = true;
}
void
MD5_native::digest(Digest result)
{
memcpy(result, digest_val, sizeof(digest_val));
}
// MD5 basic transformation. Transforms state based on block.
void MD5_native::transform(uint32_t state[4], unsigned char block[64])
{
uint32_t a = state[0], b = state[1], c = state[2], d = state[3], x[16];
decode(x, block, 64);
// Round 1
FF (a, b, c, d, x[ 0], S11, 0xd76aa478); // 1
FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); // 2
FF (c, d, a, b, x[ 2], S13, 0x242070db); // 3
FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); // 4
FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); // 5
FF (d, a, b, c, x[ 5], S12, 0x4787c62a); // 6
FF (c, d, a, b, x[ 6], S13, 0xa8304613); // 7
FF (b, c, d, a, x[ 7], S14, 0xfd469501); // 8
FF (a, b, c, d, x[ 8], S11, 0x698098d8); // 9
FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); // 10
FF (c, d, a, b, x[10], S13, 0xffff5bb1); // 11
FF (b, c, d, a, x[11], S14, 0x895cd7be); // 12
FF (a, b, c, d, x[12], S11, 0x6b901122); // 13
FF (d, a, b, c, x[13], S12, 0xfd987193); // 14
FF (c, d, a, b, x[14], S13, 0xa679438e); // 15
FF (b, c, d, a, x[15], S14, 0x49b40821); // 16
// Round 2
GG (a, b, c, d, x[ 1], S21, 0xf61e2562); // 17
GG (d, a, b, c, x[ 6], S22, 0xc040b340); // 18
GG (c, d, a, b, x[11], S23, 0x265e5a51); // 19
GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); // 20
GG (a, b, c, d, x[ 5], S21, 0xd62f105d); // 21
GG (d, a, b, c, x[10], S22, 0x2441453); // 22
GG (c, d, a, b, x[15], S23, 0xd8a1e681); // 23
GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); // 24
GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); // 25
GG (d, a, b, c, x[14], S22, 0xc33707d6); // 26
GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); // 27
GG (b, c, d, a, x[ 8], S24, 0x455a14ed); // 28
GG (a, b, c, d, x[13], S21, 0xa9e3e905); // 29
GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); // 30
GG (c, d, a, b, x[ 7], S23, 0x676f02d9); // 31
GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); // 32
// Round 3
HH (a, b, c, d, x[ 5], S31, 0xfffa3942); // 33
HH (d, a, b, c, x[ 8], S32, 0x8771f681); // 34
HH (c, d, a, b, x[11], S33, 0x6d9d6122); // 35
HH (b, c, d, a, x[14], S34, 0xfde5380c); // 36
HH (a, b, c, d, x[ 1], S31, 0xa4beea44); // 37
HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); // 38
HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); // 39
HH (b, c, d, a, x[10], S34, 0xbebfbc70); // 40
HH (a, b, c, d, x[13], S31, 0x289b7ec6); // 41
HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); // 42
HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); // 43
HH (b, c, d, a, x[ 6], S34, 0x4881d05); // 44
HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); // 45
HH (d, a, b, c, x[12], S32, 0xe6db99e5); // 46
HH (c, d, a, b, x[15], S33, 0x1fa27cf8); // 47
HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); // 48
// Round 4
II (a, b, c, d, x[ 0], S41, 0xf4292244); // 49
II (d, a, b, c, x[ 7], S42, 0x432aff97); // 50
II (c, d, a, b, x[14], S43, 0xab9423a7); // 51
II (b, c, d, a, x[ 5], S44, 0xfc93a039); // 52
II (a, b, c, d, x[12], S41, 0x655b59c3); // 53
II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); // 54
II (c, d, a, b, x[10], S43, 0xffeff47d); // 55
II (b, c, d, a, x[ 1], S44, 0x85845dd1); // 56
II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); // 57
II (d, a, b, c, x[15], S42, 0xfe2ce6e0); // 58
II (c, d, a, b, x[ 6], S43, 0xa3014314); // 59
II (b, c, d, a, x[13], S44, 0x4e0811a1); // 60
II (a, b, c, d, x[ 4], S41, 0xf7537e82); // 61
II (d, a, b, c, x[11], S42, 0xbd3af235); // 62
II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); // 63
II (b, c, d, a, x[ 9], S44, 0xeb86d391); // 64
state[0] += a;
state[1] += b;
state[2] += c;
state[3] += d;
// Zeroize sensitive information.
memset (x, 0, sizeof (x));
}
// Encodes input (uint32_t) into output (unsigned char). Assumes len is a
// multiple of 4.
void MD5_native::encode(unsigned char *output, uint32_t *input, size_t len)
{
unsigned int i, j;
for (i = 0, j = 0; j < len; i++, j += 4) {
output[j] = static_cast<unsigned char>(input[i] & 0xff);
output[j+1] = static_cast<unsigned char>((input[i] >> 8) & 0xff);
output[j+2] = static_cast<unsigned char>((input[i] >> 16) & 0xff);
output[j+3] = static_cast<unsigned char>((input[i] >> 24) & 0xff);
}
}
// Decodes input (unsigned char) into output (uint32_t). Assumes len is a
// multiple of 4.
void MD5_native::decode(uint32_t *output, unsigned char *input, size_t len)
{
unsigned int i, j;
for (i = 0, j = 0; j < len; i++, j += 4)
output[i] =
static_cast<uint32_t>(input[j]) |
(static_cast<uint32_t>(input[j+1]) << 8) |
(static_cast<uint32_t>(input[j+2]) << 16) |
(static_cast<uint32_t>(input[j+3]) << 24);
}