{----------------------------------------------------------------------------}
{ }
{ File(s): qcommon/md4.c }
{ }
{ Initial conversion by : D-12 (d-12@laposte.net) }
{ Initial conversion on : 08-Jan-2002 }
{ }
{ This File contains part of convertion of Quake2 source to ObjectPascal. }
{ More information about this project can be found at: }
{ http://www.sulaco.co.za/quake2/ }
{ }
{ Copyright (C) 1997-2001 Id Software, Inc. }
{ }
{ This program is free software; you can redistribute it and/or }
{ modify it under the terms of the GNU General Public License }
{ as published by the Free Software Foundation; either version 2 }
{ of the License, or (at your option) any later version. }
{ }
{ This program is distributed in the hope that it will be useful, }
{ but WITHOUT ANY WARRANTY; without even the implied warranty of }
{ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. }
{ }
{ See the GNU General Public License for more details. }
{ }
{----------------------------------------------------------------------------}
{ * Updated: }
{ 1) 03-Mar-2002 - Clootie (clootie@reactor.ru) }
{ Exported Com_BlockChecksum function. }
{----------------------------------------------------------------------------}
{ * TODO: }
{----------------------------------------------------------------------------}
unit MD4;
interface
type
PUINT2 = ^UINT2;
UINT2 = Word;
PUINT4 = ^UINT4;
UINT4 = Cardinal;
type
PState = ^TState;
TState = array[0..3] of UINT4;
PCount = ^TCount;
TCount = array[0..1] of UINT4;
PBuffer = ^TBuffer;
TBuffer = array[0..63] of Char;
TCardinalArray = array[0..2222222] of Cardinal;
PCardinalArray = ^TCardinalArray;
(* MD4 context. *)
PMD4_CTX = ^MD4_CTX;
MD4_CTX = record
state: TState; (* state (ABCD) *)
count: TCount; (* number of bits, modulo 2^64 (lsb first) *)
buffer: TBuffer; (* input buffer *)
end;
PDigest = ^TDigest;
TDigest = array[0..15] of Char;
procedure MD4Init(context: PMD4_CTX);
procedure MD4Update(context: PMD4_CTX; input: PChar; inputLen: Cardinal);
procedure MD4Final(digest: PDigest; context: PMD4_CTX);
function Com_BlockChecksum(buffer: Pointer; length: Integer): Cardinal;
implementation
(* MD4C.C - RSA Data Security, Inc., MD4 message-digest algorithm *)
(* Copyright (C) 1990-2, RSA Data Security, Inc. All rights reserved.
License to copy and use this software is granted provided that it
is identified as the "RSA Data Security, Inc. MD4 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. MD4 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.
*)
(* Constants for MD4Transform routine. *)
const
S11 = 3;
S12 = 7;
S13 = 11;
S14 = 19;
S21 = 3;
S22 = 5;
S23 = 9;
S24 = 13;
S31 = 3;
S32 = 9;
S33 = 11;
S34 = 15;
procedure MD4Transform(state: PState; block: PBuffer); forward;
procedure Encode(output: PChar; input: PUINT4; len: Cardinal); forward;
procedure Decode(output: PUINT4; input: PChar; len: Cardinal); forward;
const
PADDING: array[0..63] of Char =
(#$80, #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 and H are basic MD4 functions. *)
function F(x, y, z: UINT4): UINT4;
begin
Result := (x and y) or ((not x) and z);
end;
function G(x, y, z: UINT4): UINT4;
begin
Result := (x and y) or (x and z) or (y and z);
end;
function H(x, y, z: UINT4): UINT4;
begin
Result := x xor y xor z;
end;
(* ROTATE_LEFT rotates x left n bits. *)
function ROTATE_LEFT(x, n: UINT4): UINT4;
begin
Result := (x shl n) or (x shr (32 - n));
end;
(* FF, GG and HH are transformations for rounds 1, 2 and 3 *)
(* Rotation is separate from addition to prevent recomputation *)
procedure FF(var a, b, c, d, x: UINT4; s: Byte);
begin
a := Cardinal(a + F(b, c, d) + x);
a := ROTATE_LEFT(a, s);
end;
procedure GG(var a, b, c, d, x: UINT4; s: Byte);
begin
Inc(a, G(b, c, d) + x + UINT4($5A827999));
a := ROTATE_LEFT(a, s);
end;
procedure HH(var a, b, c, d, x: UINT4; s: Byte);
begin
Inc(a, H(b, c, d) + x + UINT4($6ED9EBA1));
a := ROTATE_LEFT(a, s);
end;
(* MD4 initialization. Begins an MD4 operation, writing a new context. *)
procedure MD4Init(context: PMD4_CTX);
begin
context^.count[0] := 0;
context^.count[1] := 0;
(* Load magic initialization constants.*)
context^.state[0] := $67452301;
context^.state[1] := $EFCDAB89;
context^.state[2] := $98BADCFE;
context^.state[3] := $10325476;
end;
(* MD4 block update operation. Continues an MD4 message-digest operation,
processing another message block, and updating the context. *)
procedure MD4Update(context: PMD4_CTX; input: PChar; inputLen: Cardinal);
var
i, index, partLen: Cardinal;
begin
(* Compute number of bytes mod 64 *)
index := (context^.count[0] shr 3) and $3F;
(* Update number of bits *)
Inc(context^.count[0], inputLen shl 3);
if context^.count[0] < (inputLen shl 3) then
Inc(context^.count[1]);
Inc(context^.count[1], inputLen shr 29);
partLen := 64 - index;
(* Transform as many times as possible.*)
if inputLen >= partLen then
begin
Move(input^, context^.buffer[index], partLen);
MD4Transform(@context^.state, @context^.buffer);
i := partLen;
while i + 63 < inputLen do
begin
MD4Transform(@context^.state, PBuffer(@input[i]));
Inc(i, 64);
end;
index := 0;
end
else
begin
i := 0;
end;
(* Buffer remaining input *)
Move(input[I], context^.buffer[index], inputLen - i);
end;
(* MD4 finalization. Ends an MD4 message-digest operation, writing the the
message digest and zeroizing the context. *)
procedure MD4Final(digest: PDigest; context: PMD4_CTX);
var
bits: array[0..7] of Char;
index, padLen: Cardinal;
begin
(* Save number of bits *)
Encode(@bits, @context^.count, 8);
(* Pad out to 56 mod 64.*)
index := (context^.count[0] shr 3) and $3F;
if index < 56 then
padLen := 56 - index
else
padLen := 120 - index;
MD4Update(context, PADDING, padLen);
(* Append length (before padding) *)
MD4Update(context, bits, 8);
(* Store state in digest *)
Encode(PChar(digest), @context^.state, 16);
(* Zeroize sensitive information.*)
FillChar(context^.state, SizeOf(context^.state), 0);
end;
(* MD4 basic transformation. Transforms state based on block. *)
procedure MD4Transform(state: PState; block: PBuffer);
var
a, b, c, d: UINT4;
x: array[0..15] of UINT4;
begin
a := state^[0];
b := state^[1];
c := state^[2];
d := state^[3];
Decode(@x, PChar(block), 64);
(* Round 1 *)
FF(a, b, c, d, x[0], S11); (* 1 *)
FF(d, a, b, c, x[1], S12); (* 2 *)
FF(c, d, a, b, x[2], S13); (* 3 *)
FF(b, c, d, a, x[3], S14); (* 4 *)
FF(a, b, c, d, x[4], S11); (* 5 *)
FF(d, a, b, c, x[5], S12); (* 6 *)
FF(c, d, a, b, x[6], S13); (* 7 *)
FF(b, c, d, a, x[7], S14); (* 8 *)
FF(a, b, c, d, x[8], S11); (* 9 *)
FF(d, a, b, c, x[9], S12); (* 10 *)
FF(c, d, a, b, x[10], S13); (* 11 *)
FF(b, c, d, a, x[11], S14); (* 12 *)
FF(a, b, c, d, x[12], S11); (* 13 *)
FF(d, a, b, c, x[13], S12); (* 14 *)
FF(c, d, a, b, x[14], S13); (* 15 *)
FF(b, c, d, a, x[15], S14); (* 16 *)
(* Round 2 *)
GG(a, b, c, d, x[0], S21); (* 17 *)
GG(d, a, b, c, x[4], S22); (* 18 *)
GG(c, d, a, b, x[8], S23); (* 19 *)
GG(b, c, d, a, x[12], S24); (* 20 *)
GG(a, b, c, d, x[1], S21); (* 21 *)
GG(d, a, b, c, x[5], S22); (* 22 *)
GG(c, d, a, b, x[9], S23); (* 23 *)
GG(b, c, d, a, x[13], S24); (* 24 *)
GG(a, b, c, d, x[2], S21); (* 25 *)
GG(d, a, b, c, x[6], S22); (* 26 *)
GG(c, d, a, b, x[10], S23); (* 27 *)
GG(b, c, d, a, x[14], S24); (* 28 *)
GG(a, b, c, d, x[3], S21); (* 29 *)
GG(d, a, b, c, x[7], S22); (* 30 *)
GG(c, d, a, b, x[11], S23); (* 31 *)
GG(b, c, d, a, x[15], S24); (* 32 *)
(* Round 3 *)
HH(a, b, c, d, x[0], S31); (* 33 *)
HH(d, a, b, c, x[8], S32); (* 34 *)
HH(c, d, a, b, x[4], S33); (* 35 *)
HH(b, c, d, a, x[12], S34); (* 36 *)
HH(a, b, c, d, x[2], S31); (* 37 *)
HH(d, a, b, c, x[10], S32); (* 38 *)
HH(c, d, a, b, x[6], S33); (* 39 *)
HH(b, c, d, a, x[14], S34); (* 40 *)
HH(a, b, c, d, x[1], S31); (* 41 *)
HH(d, a, b, c, x[9], S32); (* 42 *)
HH(c, d, a, b, x[5], S33); (* 43 *)
HH(b, c, d, a, x[13], S34); (* 44 *)
HH(a, b, c, d, x[3], S31); (* 45 *)
HH(d, a, b, c, x[11], S32); (* 46 *)
HH(c, d, a, b, x[7], S33); (* 47 *)
HH(b, c, d, a, x[15], S34); (* 48 *)
state^[0] := state^[0] + a;
state^[1] := state^[1] + b;
state^[2] := state^[2] + c;
state^[3] := state^[3] + d;
(* Zeroize sensitive information.*)
FillChar(x, SizeOf(x), 0);
end;
(* Encodes input (UINT4) into output (unsigned char). Assumes len is a multiple
of 4. *)
procedure Encode(output: PChar; input: PUINT4; len: Cardinal);
var
i, j: Cardinal;
begin
i := 0;
j := 0;
while j < len do
begin
output[j] := Char(PCardinalArray(input)[i] and $FF);
output[j + 1] := Char((PCardinalArray(input)[i] shr 8) and $FF);
output[j + 2] := Char((PCardinalArray(input)[i] shr 16) and $FF);
output[j + 3] := Char((PCardinalArray(input)[i] shr 24) and $FF);
Inc(i);
Inc(j, 4);
end;
end;
(* Decodes input (unsigned char) into output (UINT4). Assumes len is a multiple
of 4. *)
procedure Decode(output: PUINT4; input: PChar; len: Cardinal);
//type
// TUINT4Array = array[0..222222] of UINT4;
var
i, j: Cardinal;
begin
i := 0;
j := 0;
while j < len do
begin
PCardinalArray(output)[i] := Byte(input[j]) or (Byte(input[j + 1]) shl 8) or
(Byte(input[j + 2]) shl 16) or (Byte(input[j + 3]) shl 24);
Inc(i);
Inc(j, 4);
end;
end;
//===================================================================
function Com_BlockChecksum(buffer: Pointer; length: Integer): Cardinal;
var
digest: array[0..3] of Cardinal;
ctx: MD4_CTX;
begin
MD4Init(@ctx);
MD4Update(@ctx, PChar(Buffer), length);
MD4Final(@digest, @ctx);
Result := digest[0] xor digest[1] xor digest[2] xor digest[3];
end;
end.
