(svn r11695) -Codechange: Converted the md5 algorithm to OOP

-Codechange: Adapt the md5 algorithm to the OpenTTD source

7 files changed, 240 insertions, 312 deletions

diff --git a/src/core/endian_func.hpp b/src/core/endian_func.hpp
index fa73f7f7e..1e639272c 100644
--- a/src/core/endian_func.hpp
+++ b/src/core/endian_func.hpp
@@ -25,27 +25,27 @@
 
 /* Setup alignment and conversion macros */
 #if defined(TTD_BIG_ENDIAN)
-	#define TO_BE32X(x)  (x)
-	#define FROM_BE32(x) (x)
-	#define TO_BE32(x)   (x)
 	#define FROM_BE16(x) (x)
+	#define FROM_BE32(x) (x)
 	#define TO_BE16(x)   (x)
+	#define TO_BE32(x)   (x)
+	#define TO_BE32X(x)  (x)
+	#define FROM_LE16(x) BSWAP16(x)
+	#define FROM_LE32(x) BSWAP32(x)
+	#define TO_LE16(x)   BSWAP16(x)
+	#define TO_LE32(x)   BSWAP32(x)
 	#define TO_LE32X(x)  BSWAP32(x)
-	static inline uint32 FROM_LE32(uint32 x) { return BSWAP32(x); }
-	static inline uint32 TO_LE32(uint32 x)   { return BSWAP32(x); }
-	static inline uint16 FROM_LE16(uint16 x) { return BSWAP16(x); }
-	static inline uint16 TO_LE16(uint16 x)   { return BSWAP16(x); }
 #else
+	#define FROM_BE16(x) BSWAP16(x)
+	#define FROM_BE32(x) BSWAP32(x)
+	#define TO_BE16(x)   BSWAP16(x)
+	#define TO_BE32(x)   BSWAP32(x)
 	#define TO_BE32X(x)  BSWAP32(x)
-	static inline uint32 FROM_BE32(uint32 x) { return BSWAP32(x); }
-	static inline uint32 TO_BE32(uint32 x)   { return BSWAP32(x); }
-	static inline uint16 FROM_BE16(uint16 x) { return BSWAP16(x); }
-	static inline uint16 TO_BE16(uint16 x)   { return BSWAP16(x); }
-	#define TO_LE32X(x)  (x)
-	#define FROM_LE32(x) (x)
-	#define TO_LE32(x)   (x)
 	#define FROM_LE16(x) (x)
+	#define FROM_LE32(x) (x)
 	#define TO_LE16(x)   (x)
+	#define TO_LE32(x)   (x)
+	#define TO_LE32X(x)  (x)
 #endif /* TTD_BIG_ENDIAN */
 
 static inline uint16 ReadLE16Aligned(const void *x)
diff --git a/src/gfxinit.cpp b/src/gfxinit.cpp
index 73c289cc2..d5f54c442 100644
--- a/src/gfxinit.cpp
+++ b/src/gfxinit.cpp
@@ -20,7 +20,7 @@
 
 struct MD5File {
 	const char * filename;     ///< filename
-	md5_byte_t hash[16];       ///< md5 sum of the file
+	uint8 hash[16];            ///< md5 sum of the file
 };
 
 struct FileList {
@@ -108,20 +108,19 @@ static bool FileMD5(const MD5File file)
 	FILE *f = FioFOpenFile(file.filename, "rb", DATA_DIR, &size);
 
 	if (f != NULL) {
-		md5_state_t filemd5state;
-		md5_byte_t buffer[1024];
-		md5_byte_t digest[16];
+		Md5 checksum;
+		uint8 buffer[1024];
+		uint8 digest[16];
 		size_t len;
 
-		md5_init(&filemd5state);
 		while ((len = fread(buffer, 1, (size > sizeof(buffer)) ? sizeof(buffer) : size, f)) != 0 && size != 0) {
 			size -= len;
-			md5_append(&filemd5state, buffer, len);
+			checksum.Append(buffer, len);
 		}
 
 		FioFCloseFile(f);
 
-		md5_finish(&filemd5state, digest);
+		checksum.Finish(digest);
 		return memcmp(file.hash, digest, sizeof(file.hash)) == 0;
 	} else { // file not found
 		return false;
diff --git a/src/md5.cpp b/src/md5.cpp
index 6dd8964b9..01e863873 100644
--- a/src/md5.cpp
+++ b/src/md5.cpp
@@ -31,7 +31,7 @@
 
   This code implements the MD5 Algorithm defined in RFC 1321, whose
   text is available at
-	http://www.ietf.org/rfc/rfc1321.txt
+  http://www.ietf.org/rfc/rfc1321.txt
   The code is derived from the text of the RFC, including the test suite
   (section A.5) but excluding the rest of Appendix A.  It does not include
   any code or documentation that is identified in the RFC as being
@@ -41,33 +41,27 @@
   <ghost@aladdin.com>.  Other authors are noted in the change history
   that follows (in reverse chronological order):
 
+  2007-12-24 Changed to C++ and adapted to OpenTTD source
   2002-04-13 lpd Clarified derivation from RFC 1321; now handles byte order
-	either statically or dynamically; added missing #include <string.h>
-	in library.
+             either statically or dynamically; added missing #include <string.h>
+             in library.
   2002-03-11 lpd Corrected argument list for main(), and added int return
-	type, in test program and T value program.
+             type, in test program and T value program.
   2002-02-21 lpd Added missing #include <stdio.h> in test program.
   2000-07-03 lpd Patched to eliminate warnings about "constant is
-	unsigned in ANSI C, signed in traditional"; made test program
-	self-checking.
+             unsigned in ANSI C, signed in traditional"; made test program
+             self-checking.
   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.
  */
 
 #include "stdafx.h"
+#include "core/bitmath_func.hpp"
 #include "core/endian_func.hpp"
 #include "md5.h"
-#include <string.h>
 
-#undef BYTE_ORDER /* 1 = big-endian, -1 = little-endian, 0 = unknown */
-#if defined(TTD_BIG_ENDIAN)
-#  define BYTE_ORDER 1
-#else
-#  define BYTE_ORDER -1
-#endif
-
-#define T_MASK ((md5_word_t)~0)
+#define T_MASK ((uint32)~0)
 #define T1 /* 0xd76aa478 */ (T_MASK ^ 0x28955b87)
 #define T2 /* 0xe8c7b756 */ (T_MASK ^ 0x173848a9)
 #define T3    0x242070db
@@ -133,255 +127,197 @@
 #define T63    0x2ad7d2bb
 #define T64 /* 0xeb86d391 */ (T_MASK ^ 0x14792c6e)
 
+static inline void Md5Set1(const uint32 *X, uint32 *a, const uint32 *b, const uint32 *c, const uint32 *d, const uint8 k, const uint8 s, const uint32 Ti)
+{
+	uint32 t = (*b & *c) | (~*b & *d);
+	t += *a + X[k] + Ti;
+	*a = ROL(t, s) + *b;
+}
 
-static void
-md5_process(md5_state_t *pms, const md5_byte_t *data /*[64]*/)
+static inline void Md5Set2(const uint32 *X, uint32 *a, const uint32 *b, const uint32 *c, const uint32 *d, const uint8 k, const uint8 s, const uint32 Ti)
 {
-    md5_word_t
-	a = pms->abcd[0], b = pms->abcd[1],
-	c = pms->abcd[2], d = pms->abcd[3];
-    md5_word_t t;
-#if BYTE_ORDER > 0
-    /* Define storage only for big-endian CPUs. */
-    md5_word_t X[16];
-#else
-    /* Define storage for little-endian or both types of CPUs. */
-    md5_word_t xbuf[16];
-    const md5_word_t *X;
-#endif
-
-    {
-#if BYTE_ORDER == 0
-	/*
-	 * Determine dynamically whether this is a big-endian or
-	 * little-endian machine, since we can use a more efficient
-	 * algorithm on the latter.
-	 */
-	static const int w = 1;
-
-	if (*((const md5_byte_t *)&w)) /* dynamic little-endian */
-#endif
-#if BYTE_ORDER <= 0 /* little-endian */
-	{
-	    /*
-	     * On little-endian machines, we can process properly aligned
-	     * data without copying it.
-	     */
-	    if (!((data - (const md5_byte_t *)0) & 3)) {
-		/* data are properly aligned */
-		X = (const md5_word_t *)data;
-	    } else {
-		/* not aligned */
-		memcpy(xbuf, data, 64);
-		X = xbuf;
-	    }
-	}
-#endif
-#if BYTE_ORDER == 0
-	else /* dynamic big-endian */
-#endif
-#if BYTE_ORDER >= 0 /* big-endian */
-	{
-	    /*
-	     * On big-endian machines, we must arrange the bytes in the
-	     * right order.
-	     */
-	    const md5_byte_t *xp = data;
-	    int i;
-
-#  if BYTE_ORDER == 0
-	    X = xbuf; /* (dynamic only) */
-#  else
-#    define xbuf X /* (static only) */
-#  endif
-	    for (i = 0; i < 16; ++i, xp += 4)
-		xbuf[i] = xp[0] + (xp[1] << 8) + (xp[2] << 16) + (xp[3] << 24);
-	}
-#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;
+	uint32 t = (*b & *d) | (*c & ~*d);
+	t += *a + X[k] + Ti;
+	*a = ROL(t, s) + *b;
+}
+
+
+static inline void Md5Set3(const uint32 *X, uint32 *a, const uint32 *b, const uint32 *c, const uint32 *d, const uint8 k, const uint8 s, const uint32 Ti)
+{
+	uint32 t = *b ^ *c ^ *d;
+	t += *a + X[k] + Ti;
+	*a = ROL(t, s) + *b;
 }
 
-void
-md5_init(md5_state_t *pms)
+static inline void Md5Set4(const uint32 *X, uint32 *a, const uint32 *b, const uint32 *c, const uint32 *d, const uint8 k, const uint8 s, const uint32 Ti)
 {
-    pms->count[0] = pms->count[1] = 0;
-    pms->abcd[0] = 0x67452301;
-    pms->abcd[1] = /*0xefcdab89*/ T_MASK ^ 0x10325476;
-    pms->abcd[2] = /*0x98badcfe*/ T_MASK ^ 0x67452301;
-    pms->abcd[3] = 0x10325476;
+	uint32 t = *c ^ (*b | ~*d);
+	t += *a + X[k] + Ti;
+	*a = ROL(t, s) + *b;
 }
 
-void
-md5_append(md5_state_t *pms, const void *data, size_t nbytes)
+Md5::Md5()
 {
-    const md5_byte_t *p = (const md5_byte_t *)data;
-    size_t left = nbytes;
-    size_t offset = (pms->count[0] >> 3) & 63;
-    md5_word_t nbits = (md5_word_t)(nbytes << 3);
-
-    if (nbytes <= 0)
-	return;
-
-    /* Update the message length. */
-    pms->count[1] += (md5_word_t)(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);
+	count[0] = 0;
+	count[1] = 0;
+	abcd[0] = 0x67452301;
+	abcd[1] = /*0xefcdab89*/ T_MASK ^ 0x10325476;
+	abcd[2] = /*0x98badcfe*/ T_MASK ^ 0x67452301;
+	abcd[3] = 0x10325476;
+}
+
+void Md5::Process(const uint8 *data /*[64]*/)
+{
+	uint32 a = this->abcd[0];
+	uint32 b = this->abcd[1];
+	uint32 c = this->abcd[2];
+	uint32 d = this->abcd[3];
+
+	uint32 X[16];
+
+	/* Convert the uint8 data to uint32 LE */
+	uint32 *px = (uint32 *)data;
+	for (uint i = 0; i < 16; i++) {
+		X[i] = TO_LE32(*px);
+		px++;
+	}
+
+	/* Round 1. */
+	Md5Set1(X, &a, &b, &c, &d,  0,  7,  T1);
+	Md5Set1(X, &d, &a, &b, &c,  1, 12,  T2);
+	Md5Set1(X, &c, &d, &a, &b,  2, 17,  T3);
+	Md5Set1(X, &b, &c, &d, &a,  3, 22,  T4);
+	Md5Set1(X, &a, &b, &c, &d,  4,  7,  T5);
+	Md5Set1(X, &d, &a, &b, &c,  5, 12,  T6);
+	Md5Set1(X, &c, &d, &a, &b,  6, 17,  T7);
+	Md5Set1(X, &b, &c, &d, &a,  7, 22,  T8);
+	Md5Set1(X, &a, &b, &c, &d,  8,  7,  T9);
+	Md5Set1(X, &d, &a, &b, &c,  9, 12, T10);
+	Md5Set1(X, &c, &d, &a, &b, 10, 17, T11);
+	Md5Set1(X, &b, &c, &d, &a, 11, 22, T12);
+	Md5Set1(X, &a, &b, &c, &d, 12,  7, T13);
+	Md5Set1(X, &d, &a, &b, &c, 13, 12, T14);
+	Md5Set1(X, &c, &d, &a, &b, 14, 17, T15);
+	Md5Set1(X, &b, &c, &d, &a, 15, 22, T16);
+
+	/* Round 2. */
+	Md5Set2(X, &a, &b, &c, &d,  1,  5, T17);
+	Md5Set2(X, &d, &a, &b, &c,  6,  9, T18);
+	Md5Set2(X, &c, &d, &a, &b, 11, 14, T19);
+	Md5Set2(X, &b, &c, &d, &a,  0, 20, T20);
+	Md5Set2(X, &a, &b, &c, &d,  5,  5, T21);
+	Md5Set2(X, &d, &a, &b, &c, 10,  9, T22);
+	Md5Set2(X, &c, &d, &a, &b, 15, 14, T23);
+	Md5Set2(X, &b, &c, &d, &a,  4, 20, T24);
+	Md5Set2(X, &a, &b, &c, &d,  9,  5, T25);
+	Md5Set2(X, &d, &a, &b, &c, 14,  9, T26);
+	Md5Set2(X, &c, &d, &a, &b,  3, 14, T27);
+	Md5Set2(X, &b, &c, &d, &a,  8, 20, T28);
+	Md5Set2(X, &a, &b, &c, &d, 13,  5, T29);
+	Md5Set2(X, &d, &a, &b, &c,  2,  9, T30);
+	Md5Set2(X, &c, &d, &a, &b,  7, 14, T31);
+	Md5Set2(X, &b, &c, &d, &a, 12, 20, T32);
+
+	/* Round 3. */
+	Md5Set3(X, &a, &b, &c, &d,  5,  4, T33);
+	Md5Set3(X, &d, &a, &b, &c,  8, 11, T34);
+	Md5Set3(X, &c, &d, &a, &b, 11, 16, T35);
+	Md5Set3(X, &b, &c, &d, &a, 14, 23, T36);
+	Md5Set3(X, &a, &b, &c, &d,  1,  4, T37);
+	Md5Set3(X, &d, &a, &b, &c,  4, 11, T38);
+	Md5Set3(X, &c, &d, &a, &b,  7, 16, T39);
+	Md5Set3(X, &b, &c, &d, &a, 10, 23, T40);
+	Md5Set3(X, &a, &b, &c, &d, 13,  4, T41);
+	Md5Set3(X, &d, &a, &b, &c,  0, 11, T42);
+	Md5Set3(X, &c, &d, &a, &b,  3, 16, T43);
+	Md5Set3(X, &b, &c, &d, &a,  6, 23, T44);
+	Md5Set3(X, &a, &b, &c, &d,  9,  4, T45);
+	Md5Set3(X, &d, &a, &b, &c, 12, 11, T46);
+	Md5Set3(X, &c, &d, &a, &b, 15, 16, T47);
+	Md5Set3(X, &b, &c, &d, &a,  2, 23, T48);
+
+	/* Round 4. */
+	Md5Set4(X, &a, &b, &c, &d,  0,  6, T49);
+	Md5Set4(X, &d, &a, &b, &c,  7, 10, T50);
+	Md5Set4(X, &c, &d, &a, &b, 14, 15, T51);
+	Md5Set4(X, &b, &c, &d, &a,  5, 21, T52);
+	Md5Set4(X, &a, &b, &c, &d, 12,  6, T53);
+	Md5Set4(X, &d, &a, &b, &c,  3, 10, T54);
+	Md5Set4(X, &c, &d, &a, &b, 10, 15, T55);
+	Md5Set4(X, &b, &c, &d, &a,  1, 21, T56);
+	Md5Set4(X, &a, &b, &c, &d,  8,  6, T57);
+	Md5Set4(X, &d, &a, &b, &c, 15, 10, T58);
+	Md5Set4(X, &c, &d, &a, &b,  6, 15, T59);
+	Md5Set4(X, &b, &c, &d, &a, 13, 21, T60);
+	Md5Set4(X, &a, &b, &c, &d,  4,  6, T61);
+	Md5Set4(X, &d, &a, &b, &c, 11, 10, T62);
+	Md5Set4(X, &c, &d, &a, &b,  2, 15, T63);
+	Md5Set4(X, &b, &c, &d, &a,  9, 21, T64);
+
+	/* Then perform the following additions. (That is increment each
+	 * of the four registers by the value it had before this block
+	 * was started.) */
+	this->abcd[0] += a;
+	this->abcd[1] += b;
+	this->abcd[2] += c;
+	this->abcd[3] += d;
+}
+
+void Md5::Append(const void *data, const size_t nbytes)
+{
+	const uint8 *p = (const uint8 *)data;
+	size_t left = nbytes;
+	const size_t offset = (this->count[0] >> 3) & 63;
+	const uint32 nbits = (uint32)(nbytes << 3);
+
+	if (nbytes <= 0) return;
+
+	/* Update the message length. */
+	this->count[1] += (uint32)(nbytes >> 29);
+	this->count[0] += nbits;
+
+	if (this->count[0] < nbits) this->count[1]++;
+
+	/* Process an initial partial block. */
+	if (offset) {
+		size_t copy = (offset + nbytes > 64 ? 64 - offset : nbytes);
+
+		memcpy(this->buf + offset, p, copy);
+
+		if (offset + copy < 64) return;
+
+		p += copy;
+		left -= copy;
+		this->Process(this->buf);
+	}
+
+	/* Process full blocks. */
+	for (; left >= 64; p += 64, left -= 64) this->Process(p);
+
+	/* Process a final partial block. */
+	if (left) memcpy(this->buf, p, left);
 }
 
-void
-md5_finish(md5_state_t *pms, md5_byte_t digest[16])
+void Md5::Finish(uint8 digest[16])
 {
-    static const md5_byte_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
-    };
-    md5_byte_t data[8];
-    int i;
-
-    /* Save the length before padding. */
-    for (i = 0; i < 8; ++i)
-	data[i] = (md5_byte_t)(pms->count[i >> 2] >> ((i & 3) << 3));
-    /* Pad to 56 bytes mod 64. */
-    md5_append(pms, pad, ((55 - (pms->count[0] >> 3)) & 63) + 1);
-    /* Append the length. */
-    md5_append(pms, data, 8);
-    for (i = 0; i < 16; ++i)
-	digest[i] = (md5_byte_t)(pms->abcd[i >> 2] >> ((i & 3) << 3));
+	static const uint8 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 data[8];
+	uint i;
+
+	/* Save the length before padding. */
+	for (i = 0; i < 8; ++i)
+		data[i] = (uint8)(this->count[i >> 2] >> ((i & 3) << 3));
+
+	/* Pad to 56 bytes mod 64. */
+	this->Append(pad, ((55 - (this->count[0] >> 3)) & 63) + 1);
+	/* Append the length. */
+	this->Append(data, 8);
+
+	for (i = 0; i < 16; ++i)
+		digest[i] = (uint8)(this->abcd[i >> 2] >> ((i & 3) << 3));
 }
diff --git a/src/md5.h b/src/md5.h
index 0e48fb4c2..67ddcc6a5 100644
--- a/src/md5.h
+++ b/src/md5.h
@@ -31,7 +31,7 @@
 
   This code implements the MD5 Algorithm defined in RFC 1321, whose
   text is available at
-	http://www.ietf.org/rfc/rfc1321.txt
+  http://www.ietf.org/rfc/rfc1321.txt
   The code is derived from the text of the RFC, including the test suite
   (section A.5) but excluding the rest of Appendix A.  It does not include
   any code or documentation that is identified in the RFC as being
@@ -41,13 +41,14 @@
   <ghost@aladdin.com>.  Other authors are noted in the change history
   that follows (in reverse chronological order):
 
+  2007-12-24 Changed to C++ and adapted to OpenTTD source
   2002-04-13 lpd Removed support for non-ANSI compilers; removed
-	references to Ghostscript; clarified derivation from RFC 1321;
-	now handles byte order either statically or dynamically.
+             references to Ghostscript; clarified derivation from RFC 1321;
+             now handles byte order either statically or dynamically.
   1999-11-04 lpd Edited comments slightly for automatic TOC extraction.
   1999-10-18 lpd Fixed typo in header comment (ansi2knr rather than md5);
-	added conditionalization for C++ compilation from Martin
-	Purschke <purschke@bnl.gov>.
+             added conditionalization for C++ compilation from Martin
+             Purschke <purschke@bnl.gov>.
   1999-05-03 lpd Original version.
  */
 
@@ -64,23 +65,18 @@
  * efficiently on either one than if ARCH_IS_BIG_ENDIAN is defined.
  */
 
-typedef unsigned char md5_byte_t; /* 8-bit byte */
-typedef unsigned int md5_word_t; /* 32-bit word */
+struct Md5 {
+private:
+	uint32 count[2]; ///< message length in bits, lsw first
+	uint32 abcd[4];  ///< digest buffer
+	uint8 buf[64];   ///< accumulate block
 
-/* Define the state of the MD5 Algorithm. */
-struct md5_state_t {
-    md5_word_t count[2]; /* message length in bits, lsw first */
-    md5_word_t abcd[4];  /* digest buffer */
-    md5_byte_t buf[64];  /* accumulate block */
-};
-
-/* Initialize the algorithm. */
-void md5_init(md5_state_t *pms);
+	void Process(const uint8 *data);
 
-/* Append a string to the message. */
-void md5_append(md5_state_t *pms, const void *data, size_t nbytes);
-
-/* Finish the message and return the digest. */
-void md5_finish(md5_state_t *pms, md5_byte_t digest[16]);
+public:
+	Md5();
+	void Append(const void *data, const size_t nbytes);
+	void Finish(uint8 digest[16]);
+};
 
 #endif /* MD5_INCLUDED */
diff --git a/src/network/network.cpp b/src/network/network.cpp
index b746cbbe3..187b74211 100644
--- a/src/network/network.cpp
+++ b/src/network/network.cpp
@@ -1352,8 +1352,8 @@ void NetworkGameLoop()
 
 static void NetworkGenerateUniqueId()
 {
-	md5_state_t state;
-	md5_byte_t digest[16];
+	Md5 checksum;
+	uint8 digest[16];
 	char hex_output[16*2 + 1];
 	char coding_string[NETWORK_NAME_LENGTH];
 	int di;
@@ -1361,9 +1361,8 @@ static void NetworkGenerateUniqueId()
 	snprintf(coding_string, sizeof(coding_string), "%d%s", (uint)Random(), "OpenTTD Unique ID");
 
 	/* Generate the MD5 hash */
-	md5_init(&state);
-	md5_append(&state, (const md5_byte_t*)coding_string, strlen(coding_string));
-	md5_finish(&state, digest);
+	checksum.Append((const uint8*)coding_string, strlen(coding_string));
+	checksum.Finish(digest);
 
 	for (di = 0; di < 16; ++di)
 		sprintf(hex_output + di * 2, "%02x", digest[di]);
diff --git a/src/network/network_client.cpp b/src/network/network_client.cpp
index df70842d7..0b830c179 100644
--- a/src/network/network_client.cpp
+++ b/src/network/network_client.cpp
@@ -56,14 +56,13 @@ static const char *GenerateCompanyPasswordHash(const char *password)
 	/* Add the game seed and the server's unique ID as the salt. */
 	for (uint i = 0; i < NETWORK_UNIQUE_ID_LENGTH; i++) salted_password[i] ^= _password_server_unique_id[i] ^ (_password_game_seed >> i);
 
-	md5_state_t state;
-	md5_byte_t digest[16];
+	Md5 checksum;
+	uint8 digest[16];
 	static char hashed_password[NETWORK_UNIQUE_ID_LENGTH];
 
 	/* Generate the MD5 hash */
-	md5_init(&state);
-	md5_append(&state, (const md5_byte_t*)salted_password, sizeof(salted_password));
-	md5_finish(&state, digest);
+	checksum.Append((const uint8*)salted_password, sizeof(salted_password));
+	checksum.Finish(digest);
 
 	for (int di = 0; di < 16; di++) sprintf(hashed_password + di * 2, "%02x", digest[di]);
 
diff --git a/src/newgrf_config.cpp b/src/newgrf_config.cpp
index 80257b4a3..63d314adb 100644
--- a/src/newgrf_config.cpp
+++ b/src/newgrf_config.cpp
@@ -32,8 +32,8 @@ GRFConfig *_grfconfig_static;
 static bool CalcGRFMD5Sum(GRFConfig *config)
 {
 	FILE *f;
-	md5_state_t md5state;
-	md5_byte_t buffer[1024];
+	Md5 checksum;
+	uint8 buffer[1024];
 	size_t len, size;
 
 	/* open the file */
@@ -41,12 +41,11 @@ static bool CalcGRFMD5Sum(GRFConfig *config)
 	if (f == NULL) return false;
 
 	/* calculate md5sum */
-	md5_init(&md5state);
 	while ((len = fread(buffer, 1, (size > sizeof(buffer)) ? sizeof(buffer) : size, f)) != 0 && size != 0) {
 		size -= len;
-		md5_append(&md5state, buffer, len);
+		checksum.Append(buffer, len);
 	}
-	md5_finish(&md5state, config->md5sum);
+	checksum.Finish(config->md5sum);
 
 	FioFCloseFile(f);