Rename MD5 implementation (non-bisectable)

Just rename MD5 -> MD5_native in place so that git annotate will show
the lines as having originated there.

1 files changed, 435 insertions, 0 deletions

diff --git a/libqpdf/MD5_native.cc b/libqpdf/MD5_native.cc
new file mode 100644
index 00000000..6e166a7c
--- /dev/null
+++ b/libqpdf/MD5_native.cc
@@ -0,0 +1,435 @@
+// 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 <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<UINT4>(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<UINT4>(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<UINT4>(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<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,
+		 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<UINT4>(inputLen) << 3)) <
+        (static_cast<UINT4>(inputLen) << 3))
+	count[1]++;
+    count[1] += (static_cast<UINT4>(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::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 = 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;
+}
+
+// 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 (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, 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 (UINT4). Assumes len is a
+// multiple of 4.
+void MD5::decode(UINT4 *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<UINT4>(input[j]) |
+            (static_cast<UINT4>(input[j+1]) << 8) |
+	    (static_cast<UINT4>(input[j+2]) << 16) |
+            (static_cast<UINT4>(input[j+3]) << 24);
+}
+
+// Public functions
+
+MD5::MD5()
+{
+    init();
+}
+
+void MD5::reset()
+{
+    init();
+}
+
+void MD5::encodeString(char const* str)
+{
+    size_t len = strlen(str);
+
+    update(QUtil::unsigned_char_pointer(str), len);
+    final();
+}
+
+void MD5::appendString(char const* input_string)
+{
+    update(QUtil::unsigned_char_pointer(input_string), strlen(input_string));
+}
+
+void MD5::encodeDataIncrementally(char const* data, size_t len)
+{
+    update(QUtil::unsigned_char_pointer(data), len);
+}
+
+void MD5::encodeFile(char const *filename, qpdf_offset_t up_to_offset)
+{
+    unsigned char buffer[1024];
+
+    FILE *file = QUtil::safe_fopen(filename, "rb");
+    size_t len;
+    size_t so_far = 0;
+    size_t to_try = 1024;
+    size_t up_to_size = 0;
+    if (up_to_offset >= 0)
+    {
+        up_to_size = QIntC::to_size(up_to_offset);
+    }
+    do
+    {
+	if ((up_to_offset >= 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, len);
+	    so_far += len;
+	    if ((up_to_offset >= 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();
+    return QUtil::hex_encode(
+        std::string(reinterpret_cast<char*>(digest_val), 16));
+}
+
+std::string
+MD5::getDataChecksum(char const* buf, size_t len)
+{
+    MD5 m;
+    m.encodeDataIncrementally(buf, len);
+    return m.unparse();
+}
+
+std::string
+MD5::getFileChecksum(char const* filename, qpdf_offset_t up_to_offset)
+{
+    MD5 m;
+    m.encodeFile(filename, up_to_offset);
+    return m.unparse();
+}
+
+bool
+MD5::checkDataChecksum(char const* const checksum,
+		       char const* buf, size_t len)
+{
+    std::string actual_checksum = getDataChecksum(buf, len);
+    return (checksum == actual_checksum);
+}
+
+bool
+MD5::checkFileChecksum(char const* const checksum,
+		       char const* filename, qpdf_offset_t up_to_offset)
+{
+    bool result = false;
+    try
+    {
+	std::string actual_checksum = getFileChecksum(filename, up_to_offset);
+	result = (checksum == actual_checksum);
+    }
+    catch (std::runtime_error const&)
+    {
+	// Ignore -- return false
+    }
+    return result;
+}