As per Relevance of the word following, we have this rfc below:
Network Working Group R.
Request for Comments: 1321 MIT Laboratory for Computer
and RSA Data Security, Inc
April 1992
The MD5 Message-Digest
Status of this
This memo provides information for the Internet community. It
not specify an Internet standard. Distribution of this memo
unlimited
We would like to thank Don Coppersmith, Burt Kaliski, Ralph Merkle
David Chaum, and Noam Nisan for numerous helpful comments
suggestions
Table of
1. Executive Summary 1
2. Terminology and Notation 2
3. MD5 Algorithm Description 3
4. Summary 6
5. Differences Between MD4 and MD5 6
References 7
APPENDIX A - Reference Implementation 7
Security Considerations 21
Author's Address 21
1. Executive
This document describes the MD5 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
encrypted with a private (secret) key under a public-key
such as RSA
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RFC 1321 MD5 Message-Digest Algorithm April 1992
The MD5 algorithm is designed to be quite fast on 32-bit machines.
addition, the MD5 algorithm does not require any large
tables; the algorithm can be coded quite compactly
The MD5 algorithm is an extension of the MD4 message-digest
1,2]. MD5 is slightly slower than MD4, but is more "conservative"
design. MD5 was designed because it was felt that MD4 was
being adopted for use more quickly than justified by the
critical review; because MD4 was designed to be exceptionally fast
it is "at the edge" in terms of risking successful
attack. MD5 backs off a bit, giving up a little in speed for a
greater likelihood of ultimate security. It incorporates
suggestions made by various reviewers, and contains
optimizations. The MD5 algorithm is being placed in the public
for review and possible adoption as a standard
For OSI-based applications, MD5's object identifier
md5 OBJECT IDENTIFIER ::=
iso(1) member-body(2) US(840) rsadsi(113549) digestAlgorithm(2) 5}
In the X.509 type AlgorithmIdentifier [3], the parameters for MD
should have type NULL
2. Terminology and
In this document a "word" is a 32-bit quantity and a "byte" is
eight-bit quantity. A sequence of bits can be interpreted in
natural manner as a sequence of bytes, where each consecutive
of eight bits is interpreted as a byte with the high-order (
significant) bit of each byte listed first. Similarly, a sequence
bytes can be interpreted as a sequence of 32-bit words, where
consecutive group of four bytes is interpreted as a word with
low-order (least significant) byte given first
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 the symbol "+" denote addition of words (i.e., modulo-2^32
addition). Let X <<< s denote the 32-bit value obtained by
shifting (rotating) X left by s bit positions. Let not(X) denote
bit-wise complement of X, and let X v Y denote the bit-wise OR of
and Y. Let X xor Y denote the bit-wise XOR of X and Y, and let
denote the bit-wise AND of X and Y
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3. MD5 Algorithm
We begin by supposing that we have a b-bit message as input, and
we wish to find its message digest. Here b is an
nonnegative integer; b may be zero, it need not be a multiple
eight, and it may be arbitrarily large. We imagine the bits of
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 bits)
congruent to 448, modulo 512. That is, the message is extended
that it is just 64 bits shy of being a multiple of 512 bits long
Padding is always performed, even if the length of the message
already congruent to 448, modulo 512.
Padding is performed as follows: a single "1" bit is appended to
message, and then "0" bits are appended so that the length in bits
the padded message becomes congruent to 448, modulo 512. In all,
least one bit and at most 512 bits are appended
3.2 Step 2. Append
A 64-bit representation of b (the length of the message before
padding bits were added) is appended to the result of the
step. In the unlikely event that b is greater than 2^64, then
the low-order 64 bits of b are used. (These bits are appended as
32-bit words and appended low-order word first in accordance with
previous conventions.)
At this point the resulting message (after padding with bits and
b) has a length that is an exact multiple of 512 bits. Equivalently
this message has a length that is an exact multiple of 16 (32-bit
words. Let M[0 ... N-1] denote the words of the resulting message
where N is a multiple of 16.
3.3 Step 3. Initialize MD
A four-word buffer (A,B,C,D) is used to compute the message digest
Here each of A, B, C, D is a 32-bit register. These registers
initialized to the following values in hexadecimal, low-order
first):
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word A: 01 23 45 67
word B: 89 ab cd
word C: fe dc ba 98
word D: 76 54 32 10
3.4 Step 4. Process Message in 16-Word
We first define four auxiliary functions that each take as
three 32-bit words and produce as output one 32-bit word
F(X,Y,Z) = XY v not(X)
G(X,Y,Z) = XZ v Y not(Z
H(X,Y,Z) = X xor Y xor
I(X,Y,Z) = Y xor (X v not(Z))
In each bit position F acts as a conditional: if X then Y else Z
The function F could have been defined using + instead of v since
and not(X)Z will never have 1's in the same bit position.) It
interesting to note that if the bits of X, Y, and Z are
and unbiased, the each bit of F(X,Y,Z) will be independent
unbiased
The functions G, H, and I are similar to the function F, in that
act in "bitwise parallel" to produce their output from the bits of X
Y, and Z, in such a manner that if the corresponding bits of X, Y
and Z are independent and unbiased, then each bit of G(X,Y,Z),
H(X,Y,Z), and I(X,Y,Z) will be independent and unbiased. Note
the function H is the bit-wise "xor" or "parity" function of
inputs
This step uses a 64-element table T[1 ... 64] constructed from
sine function. Let T[i] denote the i-th element of the table,
is equal to the integer part of 4294967296 times abs(sin(i)), where
is in radians. The elements of the table are given in the appendix
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[j] to M[i*16+j].
end /* of loop on j */
/* Save A as AA, B as BB, C as CC, and D as DD. */
AA =
BB =
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CC =
DD =
/* Round 1. */
/* Let [abcd k s i] denote the
a = b + ((a + F(b,c,d) + X[k] + T[i]) <<< s). */
/* Do the following 16 operations. */
[ABCD 0 7 1] [DABC 1 12 2] [CDAB 2 17 3] [BCDA 3 22 4]
[ABCD 4 7 5] [DABC 5 12 6] [CDAB 6 17 7] [BCDA 7 22 8]
[ABCD 8 7 9] [DABC 9 12 10] [CDAB 10 17 11] [BCDA 11 22 12]
[ABCD 12 7 13] [DABC 13 12 14] [CDAB 14 17 15] [BCDA 15 22 16]
/* Round 2. */
/* Let [abcd k s i] denote the
a = b + ((a + G(b,c,d) + X[k] + T[i]) <<< s). */
/* Do the following 16 operations. */
[ABCD 1 5 17] [DABC 6 9 18] [CDAB 11 14 19] [BCDA 0 20 20]
[ABCD 5 5 21] [DABC 10 9 22] [CDAB 15 14 23] [BCDA 4 20 24]
[ABCD 9 5 25] [DABC 14 9 26] [CDAB 3 14 27] [BCDA 8 20 28]
[ABCD 13 5 29] [DABC 2 9 30] [CDAB 7 14 31] [BCDA 12 20 32]
/* Round 3. */
/* Let [abcd k s t] denote the
a = b + ((a + H(b,c,d) + X[k] + T[i]) <<< s). */
/* Do the following 16 operations. */
[ABCD 5 4 33] [DABC 8 11 34] [CDAB 11 16 35] [BCDA 14 23 36]
[ABCD 1 4 37] [DABC 4 11 38] [CDAB 7 16 39] [BCDA 10 23 40]
[ABCD 13 4 41] [DABC 0 11 42] [CDAB 3 16 43] [BCDA 6 23 44]
[ABCD 9 4 45] [DABC 12 11 46] [CDAB 15 16 47] [BCDA 2 23 48]
/* Round 4. */
/* Let [abcd k s t] denote the
a = b + ((a + I(b,c,d) + X[k] + T[i]) <<< s). */
/* Do the following 16 operations. */
[ABCD 0 6 49] [DABC 7 10 50] [CDAB 14 15 51] [BCDA 5 21 52]
[ABCD 12 6 53] [DABC 3 10 54] [CDAB 10 15 55] [BCDA 1 21 56]
[ABCD 8 6 57] [DABC 15 10 58] [CDAB 6 15 59] [BCDA 13 21 60]
[ABCD 4 6 61] [DABC 11 10 62] [CDAB 2 15 63] [BCDA 9 21 64]
/* Then perform the following additions. (That is increment
of the four registers by the value it had before this
was started.) */
A = A +
B = B +
C = C +
D = D +
end /* of loop on i */
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3.5 Step 5.
The message digest produced as output is A, B, C, D. That is,
begin with the low-order byte of A, and end with the high-order
of D
This completes the description of MD5. A reference implementation
C is given in the appendix
4.
The MD5 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 MD5
has been carefully scrutinized for weaknesses. It is, however,
relatively new algorithm and further security analysis is of
justified, as is the case with any new proposal of this sort
5. Differences Between MD4 and MD
The following are the differences between MD4 and MD5:
1. A fourth round has been added
2. Each step now has a unique additive constant
3. The function g in round 2 was changed from (XY v XZ v YZ)
(XZ v Y not(Z)) to make g less symmetric
4. Each step now adds in the result of the previous step.
promotes a faster "avalanche effect".
5. The order in which input words are accessed in rounds 2
3 is changed, to make these patterns less like each other
6. The shift amounts in each round have been
optimized, to yield a faster "avalanche effect." The shifts
different rounds are distinct
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RFC 1321 MD5 Message-Digest Algorithm April 1992
[1] Rivest, R., "The MD4 Message Digest Algorithm", RFC 1320, MIT
RSA Data Security, Inc., April 1992.
[2] Rivest, R., "The MD4 message digest algorithm", in A.J.
and S.A. Vanstone, editors, Advances in Cryptology - CRYPTO '90
Proceedings, pages 303-311, Springer-Verlag, 1991.
[3] 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
md5.h -- header file for MD
md5c.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 MD
if the symbol MD is defined on the C compiler command line as 2 or 4.
The implementation is portable and should work on many
plaforms. However, it is not difficult to optimize the
on particular platforms, an exercise left to the reader. For example
on "little-endian" platforms where the lowest-addressed byte in a 32-
bit word is the least significant and there are no
restrictions, the call to Decode in MD5Transform can be replaced
a typecast
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
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been defined with C compiler flags
*/
#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 md5.
/* MD5.H - header file for MD5C.
*/
/* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991.
rights reserved
License to copy and use this software is granted provided that
is identified as the "RSA Data Security, Inc. MD5 Message-
Algorithm" in all material mentioning or referencing this
or this function
License is also granted to make and use derivative works
that such works are identified as "derived from the RSA
Security, Inc. MD5 Message-Digest Algorithm" in all
mentioning or referencing the derived work
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
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These notices must be retained in any copies of any part of
documentation and/or software
*/
/* MD5 context. */
typedef struct {
UINT4 state[4]; /* state (ABCD) */
UINT4 count[2]; /* number of bits, modulo 2^64 (lsb first) */
unsigned char buffer[64]; /* input buffer */
} MD5_CTX
void MD5Init PROTO_LIST ((MD5_CTX *));
void MD5Update PROTO_
((MD5_CTX *, unsigned char *, unsigned int));
void MD5Final PROTO_LIST ((unsigned char [16], MD5_CTX *));
A.3 md5c.
/* MD5C.C - RSA Data Security, Inc., MD5 message-digest
*/
/* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991.
rights reserved
License to copy and use this software is granted provided that
is identified as the "RSA Data Security, Inc. MD5 Message-
Algorithm" in all material mentioning or referencing this
or this function
License is also granted to make and use derivative works
that such works are identified as "derived from the RSA
Security, Inc. MD5 Message-Digest Algorithm" in all
mentioning or referencing the derived work
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 "md5.h
/* Constants for MD5Transform routine
*/
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#define S11 7
#define S12 12
#define S13 17
#define S14 22
#define S21 5
#define S22 9
#define S23 14
#define S24 20
#define S31 4
#define S32 11
#define S33 16
#define S34 23
#define S41 6
#define S42 10
#define S43 15
#define S44 21
static void MD5Transform PROTO_LIST ((UINT4 [4], unsigned char [64]));
static void Encode PROTO_
((unsigned char *, UINT4 *, unsigned int));
static void Decode PROTO_
((UINT4 *, unsigned char *, unsigned int));
static void MD5_memcpy PROTO_LIST ((POINTER, POINTER, unsigned int));
static void MD5_memset PROTO_LIST ((POINTER, int, unsigned int));
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) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
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(a) += (b); \
}
#define GG(a, b, c, d, x, s, ac) { \
(a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
#define HH(a, b, c, d, x, s, ac) { \
(a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
#define II(a, b, c, d, x, s, ac) { \
(a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
/* MD5 initialization. Begins an MD5 operation, writing a new context
*/
void MD5Init (context
MD5_CTX *context; /* context */
context->count[0] = context->count[1] = 0;
/* Load magic initialization constants
*/
context->state[0] = 0x67452301;
context->state[1] = 0xefcdab89;
context->state[2] = 0x98badcfe
context->state[3] = 0x10325476;
/* MD5 block update operation. Continues an MD5 message-
operation, processing another message block, and updating
context
*/
void MD5Update (context, input, inputLen
MD5_CTX *context; /* context */
unsigned char *input; /* input block */
unsigned int inputLen; /* length of input block */
unsigned int i, index, partLen
/* Compute number of bytes mod 64 */
index = (unsigned int)((context->count[0] >> 3) & 0x3F);
/* Update number of bits */
if ((context->count[0] += ((UINT4)inputLen << 3))
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< ((UINT4)inputLen << 3))
context->count[1]++;
context->count[1] += ((UINT4)inputLen >> 29);
partLen = 64 - index
/* Transform as many times as possible
*/
if (inputLen >= partLen) {
MD5_
((POINTER)&context->buffer[index], (POINTER)input, partLen);
MD5Transform (context->state, context->buffer);
for (i = partLen; i + 63 < inputLen; i += 64)
MD5Transform (context->state, &input[i]);
index = 0;
}
i = 0;
/* Buffer remaining input */
MD5_
((POINTER)&context->buffer[index], (POINTER)&input[i],
inputLen-i);
/* MD5 finalization. Ends an MD5 message-digest operation, writing
the message digest and zeroizing the context
*/
void MD5Final (digest, context
unsigned char digest[16]; /* message digest */
MD5_CTX *context; /* context */
unsigned char bits[8];
unsigned int index, padLen
/* Save number of bits */
Encode (bits, context->count, 8);
/* Pad out to 56 mod 64.
*/
index = (unsigned int)((context->count[0] >> 3) & 0x3f);
padLen = (index < 56) ? (56 - index) : (120 - index);
MD5Update (context, PADDING, padLen);
/* Append length (before padding) */
MD5Update (context, bits, 8);
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/* Store state in digest */
Encode (digest, context->state, 16);
/* Zeroize sensitive information
*/
MD5_memset ((POINTER)context, 0, sizeof (*context));
/* MD5 basic transformation. Transforms state based on block
*/
static void MD5Transform (state, block
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 */
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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
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RFC 1321 MD5 Message-Digest Algorithm April 1992
*/
MD5_memset ((POINTER)x, 0, sizeof (x));
/* Encodes input (UINT4) into output (unsigned char). Assumes len
a multiple of 4.
*/
static void Encode (output, input, len
unsigned char *output
UINT4 *input
unsigned int len
unsigned int i, j
for (i = 0, j = 0; j < len; i++, j += 4) {
output[j] = (unsigned char)(input[i] & 0xff);
output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
}
/* Decodes input (unsigned char) into output (UINT4). Assumes len
a multiple of 4.
*/
static void Decode (output, input, len
UINT4 *output
unsigned char *input
unsigned int len
unsigned int i, j
for (i = 0, j = 0; j < len; i++, j += 4)
output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
(((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
/* Note: Replace "for loop" with standard memcpy if possible
*/
static void MD5_memcpy (output, input, len
POINTER output
POINTER input
unsigned int len
unsigned int i
for (i = 0; i < len; i++)
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RFC 1321 MD5 Message-Digest Algorithm April 1992
output[i] = input[i];
/* Note: Replace "for loop" with standard memset if possible
*/
static void MD5_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
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
Rivest [Page 16]
RFC 1321 MD5 Message-Digest Algorithm April 1992
#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
#
#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
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RFC 1321 MD5 Message-Digest Algorithm April 1992
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
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
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RFC 1321 MD5 Message-Digest Algorithm April 1992
("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));
("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
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RFC 1321 MD5 Message-Digest Algorithm April 1992
*/
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");
}
/* 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];
Rivest [Page 20]
RFC 1321 MD5 Message-Digest Algorithm April 1992
unsigned int i
for (i = 0; i < 16; i++)
printf ("%02x", digest[i]);
A.5 Test
The MD5 test suite (driver option "-x") should print the
results
MD5 test suite
MD5 ("") = d41d8cd98f00b204e9800998ecf8427
MD5 ("a") = 0cc175b9c0f1b6a831c399e269772661
MD5 ("abc") = 900150983cd24fb0d6963f7d28e17f72
MD5 ("message digest") = f96b697d7cb7938d525a2f31aaf161d
MD5 ("abcdefghijklmnopqrstuvwxyz") = c3fcd3d76192e4007dfb496cca67e13
MD5 ("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789") =
d174ab98d277d9f5a5611c2c9f419d9
MD5 ("123456789012345678901234567890123456789012345678901234567890123456
78901234567890") = 57edf4a22be3c955ac49da2e2107b67
Security
The level of security discussed in this memo is considered to
sufficient for implementing very high security hybrid digital
signature schemes based on MD5 and a public-key cryptosystem
Author's
Ronald L.
Massachusetts Institute of
Laboratory for Computer
NE43-324
545 Technology
Cambridge, MA 02139-1986
Phone: (617) 253-5880
EMail: rivest@theory.lcs.mit.
Rivest [Page 21]
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
