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mirror of https://github.com/qpdf/qpdf.git synced 2024-11-16 01:27:07 +00:00
qpdf/libqpdf/MD5.cc
Jay Berkenbilt 5d4cad9c02 ABI change: fix use of off_t, size_t, and integer types
Significantly improve the code's use of off_t for file offsets, size_t
for memory sizes, and integer types in cases where there has to be
compatibility with external interfaces.  Rework sections of the code
that would have prevented qpdf from working on files larger than 2 (or
maybe 4) GB in size.
2012-06-20 15:20:26 -04:00

441 lines
12 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.hh>
#include <qpdf/QUtil.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) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
#define GG(a, b, c, d, x, s, ac) { \
(a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
#define HH(a, b, c, d, x, s, ac) { \
(a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
#define II(a, b, c, d, x, s, ac) { \
(a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
// MD5 initialization. Begins an MD5 operation, writing a new context.
void MD5::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::update(unsigned char *input,
unsigned int inputLen)
{
unsigned int i, index, partLen;
// Compute number of bytes mod 64
index = (unsigned int)((count[0] >> 3) & 0x3F);
// Update number of bits
if ((count[0] += ((UINT4)inputLen << 3))
< ((UINT4)inputLen << 3))
count[1]++;
count[1] += ((UINT4)inputLen >> 29);
partLen = 64 - index;
// Transform as many times as possible.
if (inputLen >= partLen) {
memcpy
((POINTER)&buffer[index], (POINTER)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
((POINTER)&buffer[index], (POINTER)&input[i],
inputLen-i);
}
// MD5 finalization. Ends an MD5 message-digest operation, writing the
// the message digest and zeroizing the context.
void MD5::final()
{
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 = (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;
}
// MD5 basic transformation. Transforms state based on block.
void MD5::transform(UINT4 state[4], unsigned char block[64])
{
UINT4 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 ((POINTER)x, 0, sizeof (x));
}
// Encodes input (UINT4) into output (unsigned char). Assumes len is a
// multiple of 4.
void MD5::encode(unsigned char *output, UINT4 *input, unsigned int len)
{
unsigned int i, j;
for (i = 0, j = 0; j < len; i++, j += 4) {
output[j] = (unsigned char)(input[i] & 0xff);
output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
}
}
// Decodes input (unsigned char) into output (UINT4). Assumes len is a
// multiple of 4.
void MD5::decode(UINT4 *output, unsigned char *input, unsigned int len)
{
unsigned int i, j;
for (i = 0, j = 0; j < len; i++, j += 4)
output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
(((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
}
// Public functions
MD5::MD5()
{
init();
}
void MD5::reset()
{
init();
}
void MD5::encodeString(char const* str)
{
unsigned int len = (unsigned int)strlen(str);
update((unsigned char *)str, len);
final();
}
void MD5::appendString(char const* input_string)
{
update((unsigned char *)input_string, (unsigned int) strlen(input_string));
}
void MD5::encodeDataIncrementally(char const* data, int len)
{
update((unsigned char *)data, len);
}
void MD5::encodeFile(char const *filename, int up_to_size)
{
unsigned char buffer[1024];
FILE *file = QUtil::fopen_wrapper(
std::string("MD5: open ") + filename,
fopen(filename, "rb"));
size_t len;
int so_far = 0;
int to_try = 1024;
do
{
if ((up_to_size >= 0) && ((so_far + to_try) > up_to_size))
{
to_try = up_to_size - so_far;
}
len = fread(buffer, 1, to_try, file);
if (len > 0)
{
update(buffer, (unsigned int) len);
so_far += len;
if ((up_to_size >= 0) && (so_far >= up_to_size))
{
break;
}
}
} while (len > 0);
if (ferror(file))
{
// Assume, perhaps incorrectly, that errno was set by the
// underlying call to read....
(void) fclose(file);
QUtil::throw_system_error(
std::string("MD5: read error on ") + filename);
}
(void) fclose(file);
final();
}
void MD5::digest(Digest result)
{
final();
memcpy(result, digest_val, sizeof(digest_val));
}
void MD5::print()
{
final();
unsigned int i;
for (i = 0; i < 16; ++i)
{
printf("%02x", digest_val[i]);
}
printf("\n");
}
std::string MD5::unparse()
{
final();
char result[33];
char* p = result;
unsigned int i;
for (i = 0; i < 16; ++i)
{
sprintf(p, "%02x", digest_val[i]);
p += 2;
}
return result;
}
std::string
MD5::getDataChecksum(char const* buf, int len)
{
MD5 m;
m.encodeDataIncrementally(buf, len);
return m.unparse();
}
std::string
MD5::getFileChecksum(char const* filename, int up_to_size)
{
MD5 m;
m.encodeFile(filename, up_to_size);
return m.unparse();
}
bool
MD5::checkDataChecksum(char const* const checksum,
char const* buf, int len)
{
std::string actual_checksum = getDataChecksum(buf, len);
return (checksum == actual_checksum);
}
bool
MD5::checkFileChecksum(char const* const checksum,
char const* filename, int up_to_size)
{
bool result = false;
try
{
std::string actual_checksum = getFileChecksum(filename, up_to_size);
result = (checksum == actual_checksum);
}
catch (std::runtime_error)
{
// Ignore -- return false
}
return result;
}