As per Relevance of the word reference, we have this rfc below:
Network Working Group B.
Request for Comments: 1319 RSA
Updates: RFC 1115 April 1992
The MD2 Message-Digest
Status of this
This memo provides information for the Internet community. It
not specify an Internet standard. Distribution of this memo
unlimited
The description of MD2 is based on material prepared by John Linn
Ron Rivest. Their permission to incorporate that material is
appreciated
Table of
1. Executive Summary 1
2. Terminology and Notation 2
3. MD2 Algorithm Description 2
4. Summary 4
References 5
APPENDIX A - Reference Implementation 5
Security Considerations 17
Author's Address 17
1. Executive
This document describes the MD2 message-digest algorithm.
algorithm takes as input a message of arbitrary length and
as output a 128-bit "fingerprint" or "message digest" of the input
It is conjectured that it is computationally infeasible to
two messages having the same message digest, or to produce
message having a given prespecified target message digest. The MD
algorithm is intended for digital signature applications, where
large file must be "compressed" in a secure manner before
signed with a private (secret) key under a public-key
such as RSA
License to use MD2 is granted for non-commerical Internet Privacy
Enhanced Mail [1-3].
This document is an update to the August 1989 RFC 1115 [3],
also gives a reference implementation of MD2. The main
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RFC 1319 MD2 Message-Digest Algorithm April 1992
are that a textual description of MD2 is included, and that
reference implementation of MD2 is more portable
For OSI-based applications, MD2's object identifier
md2 OBJECT IDENTIFIER ::=
iso(1) member-body(2) US(840) rsadsi(113549) digestAlgorithm(2) 2}
In the X.509 type AlgorithmIdentifier [4], the parameters for MD
should have type NULL
2. Terminology and
In this document, a "byte" is an eight-bit quantity
Let x_i denote "x sub i". If the subscript is an expression,
surround it in braces, as in x_{i+1}. Similarly, we use ^
superscripts (exponentiation), so that x^i denotes x to the i-
power
Let X xor Y denote the bit-wise XOR of X and Y
3. MD2 Algorithm
We begin by supposing that we have a b-byte message as input,
that we wish to find its message digest. Here b is an
nonnegative integer; b may be zero, and it may be arbitrarily large
We imagine the bytes of the message written down as follows
m_0 m_1 ... m_{b-1}
The following five steps are performed to compute the message
of the message
3.1 Step 1. Append Padding
The message is "padded" (extended) so that its length (in bytes)
congruent to 0, modulo 16. That is, the message is extended so
it is a multiple of 16 bytes long. Padding is always performed,
if the length of the message is already congruent to 0, modulo 16.
Padding is performed as follows: "i" bytes of value "i" are
to the message so that the length in bytes of the padded
becomes congruent to 0, modulo 16. At least one byte and at most 16
16 bytes are appended
At this point the resulting message (after padding with bytes) has
length that is an exact multiple of 16 bytes. Let M[0 ... N-1]
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RFC 1319 MD2 Message-Digest Algorithm April 1992
the bytes of the resulting message, where N is a multiple of 16.
3.2 Step 2. Append
A 16-byte checksum of the message is appended to the result of
previous step
This step uses a 256-byte "random" permutation constructed from
digits of pi. Let S[i] denote the i-th element of this table.
table is given in the appendix
Do the following
/* Clear checksum. */
For i = 0 to 15 do
Set C[i] to 0.
end /* of loop on i */
Set L to 0.
/* Process each 16-word block. */
For i = 0 to N/16-1
/* Checksum block i. */
For j = 0 to 15
Set c to M[i*16+j].
Set C[j] to S[c xor L].
Set L to C[j].
end /* of loop on j */
end /* of loop on i */
The 16-byte checksum C[0 ... 15] is appended to the message. Let M[0
with checksum), where N' = N + 16.
3.3 Step 3. Initialize MD
A 48-byte buffer X is used to compute the message digest. The
is initialized to zero
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RFC 1319 MD2 Message-Digest Algorithm April 1992
3.4 Step 4. Process Message in 16-Byte
This step uses the same 256-byte permutation S as step 2 does
Do the following
/* Process each 16-word block. */
For i = 0 to N'/16-1
/* Copy block i into X. */
For j = 0 to 15
Set X[16+j] to M[i*16+j].
Set X[32+j] to (X[16+j] xor X[j]).
end /* of loop on j */
Set t to 0.
/* Do 18 rounds. */
For j = 0 to 17
/* Round j. */
For k = 0 to 47
Set t and X[k] to (X[k] xor S[t]).
end /* of loop on k */
Set t to (t+j) modulo 256.
end /* of loop on j */
end /* of loop on i */
3.5 Step 5.
The message digest produced as output is X[0 ... 15]. That is,
begin with X[0], and end with X[15].
This completes the description of MD2. A reference implementation
C is given in the appendix
4.
The MD2 message-digest algorithm is simple to implement, and
a "fingerprint" or message digest of a message of arbitrary length
It is conjectured that the difficulty of coming up with two
having the same message digest is on the order of 2^64 operations
and that the difficulty of coming up with any message having a
message digest is on the order of 2^128 operations. The MD2
has been carefully scrutinized for weaknesses. It is, however,
relatively new algorithm and further security analysis is of
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RFC 1319 MD2 Message-Digest Algorithm April 1992
justified, as is the case with any new proposal of this sort
[1] Linn, J., "Privacy Enhancement for Internet Electronic Mail:
I -- Message Encipherment and Authentication Procedures",
1113, DEC, IAB Privacy Task Force, August 1989.
[2] Kent, S., and J. Linn, "Privacy Enhancement for
Electronic Mail: Part II -- Certificate-Based Key Management",
RFC 1114, BBNCC, DEC, IAB Privacy Task Force, August 1989.
[3] Linn, J., "Privacy Enhancement for Internet Electronic Mail:
III -- Algorithms, Modes, and Identifiers", RFC 1115 DEC,
Privacy Task Force, August 1989.
[4] CCITT Recommendation X.509 (1988), "The Directory -
Authentication Framework".
APPENDIX A - Reference
This appendix contains the following files taken from RSAREF:
Cryptographic Toolkit for Privacy-Enhanced Mail
global.h -- global header
md2.h -- header file for MD
md2c.c -- source code for MD
For more information on RSAREF, send email to .
The appendix also includes the following file
mddriver.c -- test driver for MD2, MD4 and MD
The driver compiles for MD5 by default but can compile for MD2 or MD4
the symbol MD is defined on the C compiler command line as 2 or 4.
A.1 global.
/* GLOBAL.H - RSAREF types and
*/
/* PROTOTYPES should be set to one if and only if the compiler
function argument prototyping
The following makes PROTOTYPES default to 0 if it has not
been defined with C compiler flags
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RFC 1319 MD2 Message-Digest Algorithm April 1992
*/
#ifndef
#define PROTOTYPES 0
#
/* POINTER defines a generic pointer type */
typedef unsigned char *POINTER
/* UINT2 defines a two byte word */
typedef unsigned short int UINT2;
/* UINT4 defines a four byte word */
typedef unsigned long int UINT4;
/* PROTO_LIST is defined depending on how PROTOTYPES is defined above
If using PROTOTYPES, then PROTO_LIST returns the list, otherwise
returns an empty list
*/
#if
#define PROTO_LIST(list)
#
#define PROTO_LIST(list) ()
#
A.2 md2.
/* MD2.H - header file for MD2C.
*/
/* Copyright (C) 1990-2, RSA Data Security, Inc. Created 1990.
rights reserved
License to copy and use this software is granted
non-commercial Internet Privacy-Enhanced Mail provided that it
identified as the "RSA Data Security, Inc. MD2 Message
Algorithm" in all material mentioning or referencing this
or this function
RSA Data Security, Inc. makes no representations concerning
the merchantability of this software or the suitability of
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
documentation and/or software
*/
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RFC 1319 MD2 Message-Digest Algorithm April 1992
typedef struct {
unsigned char state[16]; /* state */
unsigned char checksum[16]; /* checksum */
unsigned int count; /* number of bytes, modulo 16 */
unsigned char buffer[16]; /* input buffer */
} MD2_CTX
void MD2Init PROTO_LIST ((MD2_CTX *));
void MD2Update PROTO_
((MD2_CTX *, unsigned char *, unsigned int));
void MD2Final PROTO_LIST ((unsigned char [16], MD2_CTX *));
A.3 md2c.
/* MD2C.C - RSA Data Security, Inc., MD2 message-digest
*/
/* Copyright (C) 1990-2, RSA Data Security, Inc. Created 1990.
rights reserved
License to copy and use this software is granted
non-commercial Internet Privacy-Enhanced Mail provided that it
identified as the "RSA Data Security, Inc. MD2 Message
Algorithm" in all material mentioning or referencing this
or this function
RSA Data Security, Inc. makes no representations concerning
the merchantability of this software or the suitability of
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
documentation and/or software
*/
#include "global.h
#include "md2.h
static void MD2Transform PROTO_
((unsigned char [16], unsigned char [16], unsigned char [16]));
static void MD2_memcpy PROTO_LIST ((POINTER, POINTER, unsigned int));
static void MD2_memset PROTO_LIST ((POINTER, int, unsigned int));
/* Permutation of 0..255 constructed from the digits of pi. It gives
"random" nonlinear byte substitution operation
*/
static unsigned char PI_SUBST[256] = {
41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
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RFC 1319 MD2 Message-Digest Algorithm April 1992
19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188,
76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
31, 26, 219, 153, 141, 51, 159, 17, 131, 20
};
static unsigned char *PADDING[] = {
(unsigned char *)"",
(unsigned char *)"\001",
(unsigned char *)"\002\002",
(unsigned char *)"\003\003\003",
(unsigned char *)"\004\004\004\004",
(unsigned char *)"\005\005\005\005\005",
(unsigned char *)"\006\006\006\006\006\006",
(unsigned char *)"\007\007\007\007\007\007\007",
(unsigned char *)"\010\010\010\010\010\010\010\010",
(unsigned char *)"\011\011\011\011\011\011\011\011\011",
(unsigned char *)"\012\012\012\012\012\012\012\012\012\012",
(unsigned char *)"\013\013\013\013\013\013\013\013\013\013\013",
(unsigned char *)"\014\014\014\014\014\014\014\014\014\014\014\014",
(unsigned char *)
"\015\015\015\015\015\015\015\015\015\015\015\015\015",
(unsigned char *)
"\016\016\016\016\016\016\016\016\016\016\016\016\016\016",
(unsigned char *)
"\017\017\017\017\017\017\017\017\017\017\017\017\017\017\017",
(unsigned char *)
"\020\020\020\020\020\020\020\020\020\020\020\020\020\020\020\020"
};
/* MD2 initialization. Begins an MD2 operation, writing a new context
*/
void MD2Init (context
MD2_CTX *context; /* context */
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RFC 1319 MD2 Message-Digest Algorithm April 1992
context->count = 0;
MD2_memset ((POINTER)context->state, 0, sizeof (context->state));
MD2_
((POINTER)context->checksum, 0, sizeof (context->checksum));
/* MD2 block update operation. Continues an MD2 message-
operation, processing another message block, and updating
context
*/
void MD2Update (context, input, inputLen
MD2_CTX *context; /* context */
unsigned char *input; /* input block */
unsigned int inputLen; /* length of input block */
unsigned int i, index, partLen
/* Update number of bytes mod 16 */
index = context->count
context->count = (index + inputLen) & 0xf
partLen = 16 - index
/* Transform as many times as possible
*/
if (inputLen >= partLen) {
MD2_
((POINTER)&context->buffer[index], (POINTER)input, partLen);
MD2Transform (context->state, context->checksum, context->buffer);
for (i = partLen; i + 15 < inputLen; i += 16)
MD2Transform (context->state, context->checksum, &input[i]);
index = 0;
}
i = 0;
/* Buffer remaining input */
MD2_
((POINTER)&context->buffer[index], (POINTER)&input[i],
inputLen-i);
/* MD2 finalization. Ends an MD2 message-digest operation, writing
message digest and zeroizing the context
*/
void MD2Final (digest, context
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RFC 1319 MD2 Message-Digest Algorithm April 1992
unsigned char digest[16]; /* message digest */
MD2_CTX *context; /* context */
unsigned int index, padLen
/* Pad out to multiple of 16.
*/
index = context->count
padLen = 16 - index
MD2Update (context, PADDING[padLen], padLen);
/* Extend with checksum */
MD2Update (context, context->checksum, 16);
/* Store state in digest */
MD2_memcpy ((POINTER)digest, (POINTER)context->state, 16);
/* Zeroize sensitive information
*/
MD2_memset ((POINTER)context, 0, sizeof (*context));
/* MD2 basic transformation. Transforms state and updates
based on block
*/
static void MD2Transform (state, checksum, block
unsigned char state[16];
unsigned char checksum[16];
unsigned char block[16];
unsigned int i, j, t
unsigned char x[48];
/* Form encryption block from state, block, state ^ block
*/
MD2_memcpy ((POINTER)x, (POINTER)state, 16);
MD2_memcpy ((POINTER)x+16, (POINTER)block, 16);
for (i = 0; i < 16; i++)
x[i+32] = state[i] ^ block[i];
/* Encrypt block (18 rounds).
*/
t = 0;
for (i = 0; i < 18; i++) {
for (j = 0; j < 48; j++)
t = x[j] ^= PI_SUBST[t];
t = (t + i) & 0xff
}
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RFC 1319 MD2 Message-Digest Algorithm April 1992
/* Save new state */
MD2_memcpy ((POINTER)state, (POINTER)x, 16);
/* Update checksum
*/
t = checksum[15];
for (i = 0; i < 16; i++)
t = checksum[i] ^= PI_SUBST[block[i] ^ t];
/* Zeroize sensitive information
*/
MD2_memset ((POINTER)x, 0, sizeof (x));
/* Note: Replace "for loop" with standard memcpy if possible
*/
static void MD2_memcpy (output, input, len
POINTER output
POINTER input
unsigned int len
unsigned int i
for (i = 0; i < len; i++)
output[i] = input[i];
/* Note: Replace "for loop" with standard memset if possible
*/
static void MD2_memset (output, value, len
POINTER output
int value
unsigned int len
unsigned int i
for (i = 0; i < len; i++)
((char *)output)[i] = (char)value
A.4 mddriver.
/* MDDRIVER.C - test driver for MD2, MD4 and MD
*/
/* Copyright (C) 1990-2, RSA Data Security, Inc. Created 1990.
rights reserved
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RFC 1319 MD2 Message-Digest Algorithm April 1992
RSA Data Security, Inc. makes no representations concerning
the merchantability of this software or the suitability of
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
documentation and/or software
*/
/* The following makes MD default to MD5 if it has not already
defined with C compiler flags
*/
#ifndef
#define MD MD
#
#include
#include
#include
#include "global.h
#if MD == 2
#include "md2.h
#
#if MD == 4
#include "md4.h
#
#if MD == 5
#include "md5.h
#
/* Length of test block, number of test blocks
*/
#define TEST_BLOCK_LEN 1000
#define TEST_BLOCK_COUNT 1000
static void MDString PROTO_LIST ((char *));
static void MDTimeTrial PROTO_LIST ((void));
static void MDTestSuite PROTO_LIST ((void));
static void MDFile PROTO_LIST ((char *));
static void MDFilter PROTO_LIST ((void));
static void MDPrint PROTO_LIST ((unsigned char [16]));
#if MD == 2
#define MD_CTX MD2_
#define MDInit MD2
#define MDUpdate MD2
#define MDFinal MD2
#
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RFC 1319 MD2 Message-Digest Algorithm April 1992
#if MD == 4
#define MD_CTX MD4_
#define MDInit MD4
#define MDUpdate MD4
#define MDFinal MD4
#
#if MD == 5
#define MD_CTX MD5_
#define MDInit MD5
#define MDUpdate MD5
#define MDFinal MD5
#
/* Main driver
Arguments (may be any combination):
-sstring - digests
-t - runs time
-x - runs test
filename - digests
(none) - digests standard
*/
int main (argc, argv
int argc
char *argv[];
int i
if (argc > 1)
for (i = 1; i < argc; i++)
if (argv[i][0] == '-' && argv[i][1] == 's')
MDString (argv[i] + 2);
else if (strcmp (argv[i], "-t") == 0)
MDTimeTrial ();
else if (strcmp (argv[i], "-x") == 0)
MDTestSuite ();
MDFile (argv[i]);
MDFilter ();
return (0);
/* Digests a string and prints the result
*/
static void MDString (string
char *string
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RFC 1319 MD2 Message-Digest Algorithm April 1992
MD_CTX context
unsigned char digest[16];
unsigned int len = strlen (string);
MDInit (&context);
MDUpdate (&context, string, len);
MDFinal (digest, &context);
printf ("MD%d (\"%s\") = ", MD, string);
MDPrint (digest);
printf ("\n");
/* Measures the time to digest TEST_BLOCK_COUNT TEST_BLOCK_LEN-
blocks
*/
static void MDTimeTrial ()
MD_CTX context
time_t endTime, startTime
unsigned char block[TEST_BLOCK_LEN], digest[16];
unsigned int i
("MD%d time trial. Digesting %d %d-byte blocks ...", MD
TEST_BLOCK_LEN, TEST_BLOCK_COUNT);
/* Initialize block */
for (i = 0; i < TEST_BLOCK_LEN; i++)
block[i] = (unsigned char)(i & 0xff);
/* Start timer */
time (&startTime);
/* Digest blocks */
MDInit (&context);
for (i = 0; i < TEST_BLOCK_COUNT; i++)
MDUpdate (&context, block, TEST_BLOCK_LEN);
MDFinal (digest, &context);
/* Stop timer */
time (&endTime);
printf (" done\n");
printf ("Digest = ");
MDPrint (digest);
printf ("\nTime = %ld seconds\n", (long)(endTime-startTime));
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RFC 1319 MD2 Message-Digest Algorithm April 1992
("Speed = %ld bytes/second\n",
(long)TEST_BLOCK_LEN * (long)TEST_BLOCK_COUNT/(endTime-startTime));
/* Digests a reference suite of strings and prints the results
*/
static void MDTestSuite ()
printf ("MD%d test suite:\n", MD);
MDString ("");
MDString ("a");
MDString ("abc");
MDString ("message digest");
MDString ("abcdefghijklmnopqrstuvwxyz");
("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789");
("1234567890123456789012345678901234567890\
1234567890123456789012345678901234567890");
/* Digests a file and prints the result
*/
static void MDFile (filename
char *filename
FILE *file
MD_CTX context
int len
unsigned char buffer[1024], digest[16];
if ((file = fopen (filename, "rb")) == NULL
printf ("%s can't be opened\n", filename);
else {
MDInit (&context);
while (len = fread (buffer, 1, 1024, file))
MDUpdate (&context, buffer, len);
MDFinal (digest, &context);
fclose (file);
printf ("MD%d (%s) = ", MD, filename);
MDPrint (digest);
printf ("\n");
}
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RFC 1319 MD2 Message-Digest Algorithm April 1992
/* Digests the standard input and prints the result
*/
static void MDFilter ()
MD_CTX context
int len
unsigned char buffer[16], digest[16];
MDInit (&context);
while (len = fread (buffer, 1, 16, stdin))
MDUpdate (&context, buffer, len);
MDFinal (digest, &context);
MDPrint (digest);
printf ("\n");
/* Prints a message digest in hexadecimal
*/
static void MDPrint (digest
unsigned char digest[16];
unsigned int i
for (i = 0; i < 16; i++)
printf ("%02x", digest[i]);
A.5 Test
The MD2 test suite (driver option "-x") should print the
results
MD2 test suite
MD2 ("") = 8350e5a3e24c153df2275c9f80692773
MD2 ("a") = 32ec01ec4a6dac72c0ab96fb34c0b5d
MD2 ("abc") = da853b0d3f88d99b30283a69e6ded6
MD2 ("message digest") = ab4f496bfb2a530b219ff33031fe06b
MD2 ("abcdefghijklmnopqrstuvwxyz") = 4e8ddff3650292ab5a4108c3aa47940
MD2 ("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789") =
da33def2a42df13975352846c30338
MD2 ("123456789012345678901234567890123456789012345678901234567890123456
78901234567890") = d5976f79d83d3a0dc9806c3c66f3efd
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RFC 1319 MD2 Message-Digest Algorithm April 1992
Security
The level of security discussed in this memo is considered to
sufficient for implementing very high security hybrid
signature schemes based on MD2 and a public-key cryptosystem
Author's
Burton S. Kaliski Jr
RSA Laboratories (a division of RSA Data Security, Inc.)
10 Twin Dolphin
Redwood City, CA 94065
Phone: (415) 595-8782
FAX: (415) 595-4126
EMail: burt@rsa.
Kaliski [Page 17]
if you see any problems within the linking, don't worry be happy,
this is version 0.1 of the Relevance System and you gotta expect some crappy subroutines sometimes,
just be content we did not write this in Java, which would have made this "bigger and better" HAHAHHA.
RFC documents can be found at I.E.T.F.
Relevance System Copyright © 2002 Spectrum WorldResearch
other technical nosh by ServerMasters Corporation
collaboration of BobX
