Copyright 1996-2003 John D. Polstra.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgment:
* This product includes software developed by John D. Polstra.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $Id: MD5Digest.m3.html,v 1.3 2010-04-29 17:20:02 wagner Exp $
MODULE MD5Digest;
IMPORT Text, Word;
CONST
HexTab = ARRAY [0..15] OF CHAR{
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
};
PROCEDURE Compare(READONLY a, b: T): [-1..1] =
BEGIN
FOR i := FIRST(a) TO LAST(a) DO
IF a[i] < b[i] THEN
RETURN -1;
ELSIF a[i] > b[i] THEN
RETURN 1;
END;
END;
RETURN 0;
END Compare;
PROCEDURE Equal(READONLY a, b: T): BOOLEAN =
BEGIN
RETURN a = b;
END Equal;
PROCEDURE FromText(t: TEXT): T
RAISES {Malformed} =
VAR
digest: T;
val: Word.T;
BEGIN
IF Text.Length(t) # 2*NUMBER(digest) THEN RAISE Malformed END;
FOR i := FIRST(digest) TO LAST(digest) DO
WITH ch = Text.GetChar(t, 2*i) DO
CASE ch OF
| '0'..'9' => val := ORD(ch) - ORD('0');
| 'a'..'f' => val := ORD(ch) - ORD('a') + 10;
| 'A'..'F' => val := ORD(ch) - ORD('A') + 10;
ELSE RAISE Malformed END;
END;
val := Word.Shift(val, 4);
WITH ch = Text.GetChar(t, 2*i+1) DO
CASE ch OF
| '0'..'9' => val := Word.Plus(val, ORD(ch) - ORD('0'));
| 'a'..'f' => val := Word.Plus(val, ORD(ch) - ORD('a') + 10);
| 'A'..'F' => val := Word.Plus(val, ORD(ch) - ORD('A') + 10);
ELSE RAISE Malformed END;
END;
digest[i] := val;
END;
RETURN digest;
END FromText;
PROCEDURE Hash(READONLY a: T): Word.T =
VAR
r: Word.T;
BEGIN
r :=
Word.Or(
Word.Shift(
Word.Or(
Word.Shift(
Word.Or(
Word.Shift(a[0], 8),
a[1]),
8),
a[2]),
8),
a[3]);
r :=
Word.Xor(
r,
Word.Or(
Word.Shift(
Word.Or(
Word.Shift(
Word.Or(
Word.Shift(a[4], 8),
a[5]),
8),
a[6]),
8),
a[7])
);
r :=
Word.Xor(
r,
Word.Or(
Word.Shift(
Word.Or(
Word.Shift(
Word.Or(
Word.Shift(a[8], 8),
a[9]),
8),
a[10]),
8),
a[11])
);
r :=
Word.Xor(
r,
Word.Or(
Word.Shift(
Word.Or(
Word.Shift(
Word.Or(
Word.Shift(a[12], 8),
a[13]),
8),
a[14]),
8),
a[15])
);
RETURN r;
END Hash;
PROCEDURE ToText(READONLY a: T): TEXT =
VAR
str: ARRAY [0..31] OF CHAR;
BEGIN
FOR i := FIRST(a) TO LAST(a) DO
WITH val = a[i], j = 2*i DO
str[j] := HexTab[ Word.RightShift(val, 4) ];
str[j+1] := HexTab[ Word.And(val, 16_f) ];
END;
END;
RETURN Text.FromChars(str);
END ToText;
BEGIN
END MD5Digest.