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442 lines
12 KiB
C++
442 lines
12 KiB
C++
// This file implements a class for computation of MD5 checksums.
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// It is derived from the reference algorithm for MD5 as given in
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// RFC 1321. The original copyright notice is as follows:
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//
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/////////////////////////////////////////////////////////////////////////
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//
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// Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
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// rights reserved.
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//
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// License to copy and use this software is granted provided that it
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// is identified as the "RSA Data Security, Inc. MD5 Message-Digest
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// Algorithm" in all material mentioning or referencing this software
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// or this function.
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//
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// License is also granted to make and use derivative works provided
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// that such works are identified as "derived from the RSA Data
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// Security, Inc. MD5 Message-Digest Algorithm" in all material
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// mentioning or referencing the derived work.
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//
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// RSA Data Security, Inc. makes no representations concerning either
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// the merchantability of this software or the suitability of this
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// software for any particular purpose. It is provided "as is"
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// without express or implied warranty of any kind.
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//
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// These notices must be retained in any copies of any part of this
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// documentation and/or software.
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//
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/////////////////////////////////////////////////////////////////////////
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#include <qpdf/MD5.hh>
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#include <stdio.h>
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#include <memory.h>
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#include <stdlib.h>
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#include <string.h>
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#include <errno.h>
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int const S11 = 7;
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int const S12 = 12;
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int const S13 = 17;
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int const S14 = 22;
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int const S21 = 5;
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int const S22 = 9;
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int const S23 = 14;
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int const S24 = 20;
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int const S31 = 4;
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int const S32 = 11;
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int const S33 = 16;
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int const S34 = 23;
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int const S41 = 6;
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int const S42 = 10;
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int const S43 = 15;
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int const S44 = 21;
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static unsigned char PADDING[64] = {
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0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
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};
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// F, G, H and I are basic MD5 functions.
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#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
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#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
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#define H(x, y, z) ((x) ^ (y) ^ (z))
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#define I(x, y, z) ((y) ^ ((x) | (~z)))
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// ROTATE_LEFT rotates x left n bits.
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#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
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// FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
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// Rotation is separate from addition to prevent recomputation.
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#define FF(a, b, c, d, x, s, ac) { \
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(a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); \
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(a) = ROTATE_LEFT ((a), (s)); \
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(a) += (b); \
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}
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#define GG(a, b, c, d, x, s, ac) { \
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(a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
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(a) = ROTATE_LEFT ((a), (s)); \
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(a) += (b); \
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}
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#define HH(a, b, c, d, x, s, ac) { \
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(a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
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(a) = ROTATE_LEFT ((a), (s)); \
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(a) += (b); \
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}
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#define II(a, b, c, d, x, s, ac) { \
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(a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
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(a) = ROTATE_LEFT ((a), (s)); \
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(a) += (b); \
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}
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// MD5 initialization. Begins an MD5 operation, writing a new context.
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void MD5::init()
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{
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count[0] = count[1] = 0;
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// Load magic initialization constants.
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state[0] = 0x67452301;
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state[1] = 0xefcdab89;
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state[2] = 0x98badcfe;
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state[3] = 0x10325476;
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finalized = false;
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memset(digest_val, 0, sizeof(digest_val));
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}
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// MD5 block update operation. Continues an MD5 message-digest
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// operation, processing another message block, and updating the
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// context.
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void MD5::update(unsigned char *input,
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unsigned int inputLen)
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{
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unsigned int i, index, partLen;
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// Compute number of bytes mod 64
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index = (unsigned int)((count[0] >> 3) & 0x3F);
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// Update number of bits
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if ((count[0] += ((UINT4)inputLen << 3))
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< ((UINT4)inputLen << 3))
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count[1]++;
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count[1] += ((UINT4)inputLen >> 29);
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partLen = 64 - index;
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// Transform as many times as possible.
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if (inputLen >= partLen) {
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memcpy
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((POINTER)&buffer[index], (POINTER)input, partLen);
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transform(state, buffer);
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for (i = partLen; i + 63 < inputLen; i += 64)
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transform(state, &input[i]);
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index = 0;
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}
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else
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i = 0;
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// Buffer remaining input
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memcpy
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((POINTER)&buffer[index], (POINTER)&input[i],
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inputLen-i);
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}
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// MD5 finalization. Ends an MD5 message-digest operation, writing the
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// the message digest and zeroizing the context.
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void MD5::final()
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{
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if (finalized)
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{
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return;
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}
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unsigned char bits[8];
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unsigned int index, padLen;
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// Save number of bits
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encode(bits, count, 8);
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// Pad out to 56 mod 64.
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index = (unsigned int)((count[0] >> 3) & 0x3f);
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padLen = (index < 56) ? (56 - index) : (120 - index);
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update(PADDING, padLen);
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// Append length (before padding)
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update(bits, 8);
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// Store state in digest_val
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encode(digest_val, state, 16);
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// Zeroize sensitive information.
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memset(state, 0, sizeof(state));
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memset(count, 0, sizeof(count));
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memset(buffer, 0, sizeof(buffer));
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finalized = true;
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}
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// MD5 basic transformation. Transforms state based on block.
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void MD5::transform(UINT4 state[4], unsigned char block[64])
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{
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UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
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decode(x, block, 64);
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// Round 1
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FF (a, b, c, d, x[ 0], S11, 0xd76aa478); // 1
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FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); // 2
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FF (c, d, a, b, x[ 2], S13, 0x242070db); // 3
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FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); // 4
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FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); // 5
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FF (d, a, b, c, x[ 5], S12, 0x4787c62a); // 6
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FF (c, d, a, b, x[ 6], S13, 0xa8304613); // 7
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FF (b, c, d, a, x[ 7], S14, 0xfd469501); // 8
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FF (a, b, c, d, x[ 8], S11, 0x698098d8); // 9
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FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); // 10
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FF (c, d, a, b, x[10], S13, 0xffff5bb1); // 11
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FF (b, c, d, a, x[11], S14, 0x895cd7be); // 12
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FF (a, b, c, d, x[12], S11, 0x6b901122); // 13
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FF (d, a, b, c, x[13], S12, 0xfd987193); // 14
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FF (c, d, a, b, x[14], S13, 0xa679438e); // 15
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FF (b, c, d, a, x[15], S14, 0x49b40821); // 16
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// Round 2
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GG (a, b, c, d, x[ 1], S21, 0xf61e2562); // 17
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GG (d, a, b, c, x[ 6], S22, 0xc040b340); // 18
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GG (c, d, a, b, x[11], S23, 0x265e5a51); // 19
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GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); // 20
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GG (a, b, c, d, x[ 5], S21, 0xd62f105d); // 21
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GG (d, a, b, c, x[10], S22, 0x2441453); // 22
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GG (c, d, a, b, x[15], S23, 0xd8a1e681); // 23
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GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); // 24
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GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); // 25
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GG (d, a, b, c, x[14], S22, 0xc33707d6); // 26
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GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); // 27
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GG (b, c, d, a, x[ 8], S24, 0x455a14ed); // 28
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GG (a, b, c, d, x[13], S21, 0xa9e3e905); // 29
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GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); // 30
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GG (c, d, a, b, x[ 7], S23, 0x676f02d9); // 31
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GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); // 32
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// Round 3
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HH (a, b, c, d, x[ 5], S31, 0xfffa3942); // 33
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HH (d, a, b, c, x[ 8], S32, 0x8771f681); // 34
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HH (c, d, a, b, x[11], S33, 0x6d9d6122); // 35
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HH (b, c, d, a, x[14], S34, 0xfde5380c); // 36
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HH (a, b, c, d, x[ 1], S31, 0xa4beea44); // 37
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HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); // 38
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HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); // 39
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HH (b, c, d, a, x[10], S34, 0xbebfbc70); // 40
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HH (a, b, c, d, x[13], S31, 0x289b7ec6); // 41
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HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); // 42
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HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); // 43
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HH (b, c, d, a, x[ 6], S34, 0x4881d05); // 44
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HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); // 45
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HH (d, a, b, c, x[12], S32, 0xe6db99e5); // 46
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HH (c, d, a, b, x[15], S33, 0x1fa27cf8); // 47
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HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); // 48
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// Round 4
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II (a, b, c, d, x[ 0], S41, 0xf4292244); // 49
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II (d, a, b, c, x[ 7], S42, 0x432aff97); // 50
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II (c, d, a, b, x[14], S43, 0xab9423a7); // 51
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II (b, c, d, a, x[ 5], S44, 0xfc93a039); // 52
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II (a, b, c, d, x[12], S41, 0x655b59c3); // 53
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II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); // 54
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II (c, d, a, b, x[10], S43, 0xffeff47d); // 55
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II (b, c, d, a, x[ 1], S44, 0x85845dd1); // 56
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II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); // 57
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II (d, a, b, c, x[15], S42, 0xfe2ce6e0); // 58
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II (c, d, a, b, x[ 6], S43, 0xa3014314); // 59
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II (b, c, d, a, x[13], S44, 0x4e0811a1); // 60
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II (a, b, c, d, x[ 4], S41, 0xf7537e82); // 61
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II (d, a, b, c, x[11], S42, 0xbd3af235); // 62
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II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); // 63
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II (b, c, d, a, x[ 9], S44, 0xeb86d391); // 64
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state[0] += a;
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state[1] += b;
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state[2] += c;
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state[3] += d;
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// Zeroize sensitive information.
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memset ((POINTER)x, 0, sizeof (x));
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}
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// Encodes input (UINT4) into output (unsigned char). Assumes len is a
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// multiple of 4.
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void MD5::encode(unsigned char *output, UINT4 *input, unsigned int len)
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{
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unsigned int i, j;
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for (i = 0, j = 0; j < len; i++, j += 4) {
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output[j] = (unsigned char)(input[i] & 0xff);
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output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
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output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
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output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
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}
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}
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// Decodes input (unsigned char) into output (UINT4). Assumes len is a
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// multiple of 4.
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void MD5::decode(UINT4 *output, unsigned char *input, unsigned int len)
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{
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unsigned int i, j;
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for (i = 0, j = 0; j < len; i++, j += 4)
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output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
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(((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
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}
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// Public functions
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MD5::MD5()
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{
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init();
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}
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void MD5::reset()
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{
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init();
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}
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void MD5::encodeString(char const* str)
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{
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unsigned int len = strlen(str);
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update((unsigned char *)str, len);
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final();
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}
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void MD5::appendString(char const* input_string)
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{
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update((unsigned char *)input_string, strlen(input_string));
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}
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void MD5::encodeDataIncrementally(char const* data, int len)
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{
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update((unsigned char *)data, len);
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}
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void MD5::encodeFile(char const *filename, int up_to_size)
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throw (QEXC::System)
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{
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FILE *file;
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unsigned char buffer[1024];
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if ((file = fopen (filename, "rb")) == NULL)
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{
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throw QEXC::System(std::string("MD5: can't open ") + filename, errno);
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}
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int len;
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int so_far = 0;
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int to_try = 1024;
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do
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{
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if ((up_to_size >= 0) && ((so_far + to_try) > up_to_size))
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{
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to_try = up_to_size - so_far;
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}
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len = fread(buffer, 1, to_try, file);
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if (len > 0)
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{
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update(buffer, len);
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so_far += len;
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if ((up_to_size >= 0) && (so_far >= up_to_size))
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{
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break;
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}
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}
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} while (len > 0);
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if (ferror(file))
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{
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// Assume, perhaps incorrectly, that errno was set by the
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// underlying call to read....
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(void) fclose(file);
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throw QEXC::System(std::string("MD5: read error on ") + filename, errno);
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}
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(void) fclose(file);
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final();
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}
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void MD5::digest(Digest result)
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{
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final();
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memcpy(result, digest_val, sizeof(digest_val));
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}
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void MD5::print()
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{
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final();
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unsigned int i;
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for (i = 0; i < 16; ++i)
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{
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printf("%02x", digest_val[i]);
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}
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printf("\n");
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}
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std::string MD5::unparse()
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{
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final();
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char result[33];
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char* p = result;
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unsigned int i;
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for (i = 0; i < 16; ++i)
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{
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sprintf(p, "%02x", digest_val[i]);
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p += 2;
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}
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return result;
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}
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std::string
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MD5::getDataChecksum(char const* buf, int len)
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{
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MD5 m;
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m.encodeDataIncrementally(buf, len);
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return m.unparse();
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}
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std::string
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MD5::getFileChecksum(char const* filename, int up_to_size)
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{
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MD5 m;
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m.encodeFile(filename, up_to_size);
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return m.unparse();
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}
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bool
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MD5::checkDataChecksum(char const* const checksum,
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char const* buf, int len)
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{
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std::string actual_checksum = getDataChecksum(buf, len);
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return (checksum == actual_checksum);
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}
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bool
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MD5::checkFileChecksum(char const* const checksum,
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char const* filename, int up_to_size)
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{
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bool result = false;
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try
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{
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std::string actual_checksum = getFileChecksum(filename, up_to_size);
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result = (checksum == actual_checksum);
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}
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catch (QEXC::System)
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{
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// Ignore -- return false
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}
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return result;
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}
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