Network Working Group                                          R. Rivest
INTERNET-DRAFT                       MIT Laboratory for Computer Science
                                                                S. Dusse
                                                 RSA Data Security, Inc.
                                                             1 July 1991


                    The MD4 Message-Digest Algorithm


STATUS OF THIS MEMO

   This draft document will be submitted to the RFC editor as a protocol
   specification. Comments should be sent to <pem-dev@tis.com> or to the
   authors. Distribution of this memo is unlimited.


ACKNOWLEDGEMENT

   We would like to thank Don Coppersmith, Burt Kaliski, Ralph Merkle,
   and Noam Nisan for numerous helpful comments and suggestions.


Table of Contents

   1. Executive Summary                                                1
   2. Terminology and Notation                                         2
   3. MD4 Algorithm Description                                        2
   4. Summary                                                          6
   5. Security Considerations                                          6
   References                                                          7
   Authors' Addresses                                                  7
   APPENDIX - Reference Implementation                                 8



1. Executive Summary

   This document describes the MD4 message-digest algorithm. The
   algorithm takes as input an input message of arbitrary length and
   produces as output a 128-bit "fingerprint" or "message digest" of the
   input. It is conjectured that it is computationally infeasible to
   produce two messages having the same message digest, or to produce
   any message having a given prespecified target message digest. The
   MD4 algorithm is intended for digital signature applications, where a
   large file must be "compressed" in a secure manner before being
   encrypted with a private (secret) key under a public-key cryptosystem
   such as RSA.

   The MD4 algorithm is designed to be quite fast on 32-bit machines. In
   addition, the MD4 algorithm does not require any large substitution
   tables; the algorithm can be coded quite compactly.


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   The MD4 algorithm is being placed in the public domain for review and
   possible adoption as a standard.

   This document is a proposed update to the October 1990 RFC 1186 [1].
   The main difference is that the reference implementation of MD4 in
   the appendix is more portable.

   A version of this document including the C source code in the ap-
   pendix is available by FTP from RSA.COM in the file "md4.doc".

   This document may be referred to, unofficially, as Internet draft
   [1186D].

   For OSI-based applications, MD4's object identifier is

   md4 OBJECT IDENTIFIER ::=
     {iso(1) member-body(2) US(840) rsadsi(113549) digestAlgorithm(2) 4}

   In the X.509 type AlgorithmIdentifier [3], the parameters for MD4
   should have type NULL.


2. Terminology and Notation

   In this document a "word" is a 32-bit quantity and a "byte" is an
   eight-bit quantity. A sequence of bits can be interpreted in a
   natural manner as a sequence of bytes, where each consecutive group
   of eight bits is interpreted as a byte with the high-order (most
   significant) bit of each byte listed first. Similarly, a sequence of
   bytes can be interpreted as a sequence of 32-bit words, where each
   consecutive group of four bytes is interpreted as a word with the
   low-order (least significant) byte given first.

   Let x_i denote "x sub i". If the subscript is an expression, we sur-
   round it in braces, as in x_{i+1}. Similarly, we use ^ for super-
   scripts (exponentiation), so that x^i denotes x to the i-th power.

   Let the symbol "+" denote addition of words (i.e., modulo-2^32 addi-
   tion). Let X <<< s denote the 32-bit value obtained by circularly
   shifting (rotating) X left by s bit positions. Let not(X) denote the
   bit-wise complement of X, and let X v Y denote the bit-wise OR of X
   and Y. Let X xor Y denote the bit-wise XOR of X and Y, and let XY de-
   note the bit-wise AND of X and Y.


3. MD4 Algorithm Description

   We begin by supposing that we have a b-bit message as input, and that
   we wish to find its message digest. Here b is an arbitrary nonnega-
   tive integer; b may be zero, it need not be a multiple of eight, and
   it may be arbitrarily large. We imagine the bits of the message writ-
   ten down as follows:


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                            m_0 m_1 ... m_{b-1}

   The following five steps are performed to compute the message digest
   of the message.


3.1 Step 1. Append Padding Bits

   The message is "padded" (extended) so that its length (in bits) is
   congruent to 448, modulo 512. That is, the message is extended so
   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 is al-
   ready congruent to 448, modulo 512 (in which case 512 bits of padding
   are added).

   Padding is performed as follows: a single "1" bit is appended to the
   message, and then enough zero bits are appended so that the length in
   bits of the padded message becomes congruent to 448, modulo 512.


3.2 Step 2. Append Length

   A 64-bit representation of b (the length of the message before the
   padding bits were added) is appended to the result of the previous
   step. In the unlikely event that b is greater than 2^64, then only
   the low-order 64 bits of b are used. (These bits are appended as two
   32-bit words and appended low-order word first in accordance with the
   previous conventions.)

   At this point the resulting message (after padding with bits and with
   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 Buffer

   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 are
   initialized to the following values in hexadecimal, low-order bytes
   first):

                            word A: 01 23 45 67
                            word B: 89 ab cd ef
                            word C: fe dc ba 98
                            word D: 76 54 32 10







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3.4 Step 4. Process Message in 16-Word Blocks

   We first define three auxiliary functions that each take as input
   three 32-bit words and produce as output one 32-bit word.

                          F(X,Y,Z) = XY v not(X)Z
                          G(X,Y,Z) = XY v XZ v YZ
                         H(X,Y,Z) = X xor Y xor 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 XY
   and not(X)Z will never have "1" bits in the same bit position.)  In
   each bit position G acts as a majority function: if at least two of
   X, Y, Z are on, then G has a "1" bit in that bit position, else G has
   a "0" bit. It is interesting to note that if the bits of X, Y, and Z
   are independent and unbiased, the each bit of f(X,Y,Z) will be inde-
   pendent and unbiased, and similarly each bit of g(X,Y,Z) will be in-
   dependent and unbiased. The function H is the bit-wise XOR or
   "parity" function; it has properties similar to those of F and G.

   Do the following:

   /* Process each 16-word block. */
   For i = 0 to N/16-1 do

       /* Copy block i into X. */
       For j = 0 to 15 do
           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 = A
       BB = B
       CC = C
       DD = D

       /* Round 1. */
       /* Let [a b c d k s] denote the operation
           a = (a + F(b,c,d) + X[k]) <<< s. */

       /* Do the following 16 operations. */
       [A B C D  0  3]
       [D A B C  1  7]
       [C D A B  2 11]
       [B C D A  3 19]
       [A B C D  4  3]
       [D A B C  5  7]
       [C D A B  6 11]
       [B C D A  7 19]
       [A B C D  8  3]
       [D A B C  9  7]
       [C D A B 10 11]


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       [B C D A 11 19]
       [A B C D 12  3]
       [D A B C 13  7]
       [C D A B 14 11]
       [B C D A 15 19]

       /* Round 2. */
       /* Let [a b c d k s] denote the operation
           a = (a + G(b,c,d) + X[k] + 5A827999) <<< s. */

       /* Do the following 16 operations. */
       [A B C D  0  3]
       [D A B C  4  5]
       [C D A B  8  9]
       [B C D A 12 13]
       [A B C D  1  3]
       [D A B C  5  5]
       [C D A B  9  9]
       [B C D A 13 13]
       [A B C D  2  3]
       [D A B C  6  5]
       [C D A B 10  9]
       [B C D A 14 13]
       [A B C D  3  3]
       [D A B C  7  5]
       [C D A B 11  9]
       [B C D A 15 13]

       /* Round 3. */

       /* Let [a b c d k s] denote the operation
           a = (a + H(b,c,d) + X[k] + 6ED9EBA1) <<< s. */

       /* Do the following 16 operations. */
       [A B C D  0  3]
       [D A B C  8  9]
       [C D A B  4 11]
       [B C D A 12 15]
       [A B C D  2  3]
       [D A B C 10  9]
       [C D A B  6 11]
       [B C D A 14 15]
       [A B C D  1  3]
       [D A B C  9  9]
       [C D A B  5 11]
       [B C D A 13 15]
       [A B C D  3  3]
       [D A B C 11  9]
       [C D A B  7 11]
       [B C D A 15 15]

       /* Then perform the following additions. (That is, increment each
          of the four registers by the value it had before this block

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          was started.) */
       A = A + AA
       B = B + BB
       C = C + CC
       D = D + DD

   end /* of loop on i */

   Note. The value 5A..99 is a hexadecimal 32-bit constant, written with
   the high-order digit first. This constant represents the square root
   of 2.  The octal value of this constant is 013240474631.

   The value 6E..A1 is a hexadecimal 32-bit constant, written with the
   high-order digit first.  This constant represents the square root of
   3.  The octal value of this constant is 015666365641.

   See Knuth, The Art of Programming, Volume 2 (Seminumerical Algo-
   rithms), Second Edition (1981), Addison-Wesley. Table 2, page 660.


3.5 Step 5. Output

   The message digest produced as output is A, B, C, D. That is, we be-
   gin with the low-order byte of A, and end with the high-order byte of
   D.

   This completes the description of MD4. A reference implementation in
   C is given in the Appendix.


4. Summary

   The MD4 message-digest algorithm is simple to implement, and provides
   a "fingerprint" or message digest of a message of arbitrary length.
   It is conjectured that the difficulty of coming up with two messages
   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 given
   message digest is on the order of 2^128 operations. The MD4 algorithm
   has been carefully scrutinized for weaknesses. It is, however, a rel-
   atively new algorithm and further security analysis is of course jus-
   tified, as is the case with any new proposal of this sort.


5. Security Considerations

   The level of security discussed in this memo is considered to be suf-
   ficient for implementing very high security hybrid digital-signature
   schemes based on MD4 and a public-key cryptosystem.






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References

     [1]  Rivest, R.L., The MD4 Message Digest Algorithm (RFC 1186), Oc-
          tober 1990.

     [2]  Rivest, R.L., The MD4 message digest algorithm, presented at
          CRYPTO '90 (Santa Barbara, CA, August 11-15, 1990).

     [3]  CCITT, The Directory---Authentication Framework
          (Recommendation X.509), 1988.


Authors' Addresses

   Ronald L. Rivest
   Massachusetts Institute of Technology
   Laboratory for Computer Science
   NE43-324
   545 Technology Square
   Cambridge, MA  02139-1986
   Phone: (617) 253-5880
   EMail: rivest@theory.lcs.mit.edu

   Steve Dusse
   RSA Data Security, Inc.
   10 Twin Dolphin Drive
   Redwood City, CA  94065
   Phone: (415) 595-8782
   EMail: dusse@rsa.com

























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APPENDIX - Reference Implementation

   This appendix contains the following files:

     md4.h -- header file for implementation of MD4

     md4.c -- the source code for MD4 routines

     md4driver.c -- sample test routines

     session -- sample results of running md4driver

   The implementation of MD4 given in this appendix differs from the one
   given in RFC 1186 [1] and the CRYPTO '90 paper on MD4. The main dif-
   ference is that this version should compile and run correctly on more
   platforms than the other ones. We have sacrificed performance for
   portability. MD4 speeds given in RFC 1186 and the CRYPTO '90 paper
   are not necessarily the same as those one might obtain with this ref-
   erence implementation. However, it is not difficult to improve this
   implementation on particular platforms, an exercise left to the
   reader. Following are some suggestions:

     1.   Change MD4Update so that the context is not used at all
          if it is empty (mdi == 0) and 64 or more bytes remain
          (inLen >= 64). In other words, call Transform with inBuf
          in this case. (This requires that byte ordering is cor-
          rect in inBuf.)

     2.   Implement a procedure MD4UpdateLong modeled after
          MD4Update where inBuf is UINT4 * instead of unsigned char
          *. MD4UpdateLong would call Transform directly with 16
          word blocks from inBuf. Call this instead of MD4Update in
          general. This works well if you have an I/O procedure
          that can read long words from a file.

     3.   On "little-endian" platforms where the lowest-address
          byte in a long word is the least significant (and there
          are no alignment restrictions), change MD4Update to call
          Transform directly with 64-byte blocks from inBuf
          (typecast to a UINT4 *).













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/*
 ***********************************************************************
 ** md4.h -- header file for implementation of MD4                    **
 ** RSA Data Security, Inc. MD4 Message-Digest Algorithm              **
 ** Created: 2/17/90 RLR                                              **
 ** Revised: 12/27/90 SRD,AJ,BSK,JT Reference C version               **
 ***********************************************************************
 */

/*
 ***********************************************************************
 ** Copyright (C) 1990, 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.                                    **
 ***********************************************************************
 */

/* typedef a 32-bit type */
typedef unsigned long int UINT4;

/* Data structure for MD4 (Message-Digest) computation */
typedef struct {
  UINT4 i[2];                   /* number of _bits_ handled mod 2^64 */
  UINT4 buf[4];                                    /* scratch buffer */
  unsigned char in[64];                              /* input buffer */
  unsigned char digest[16];     /* actual digest after MD4Final call */
} MD4_CTX;

void MD4Init ();
void MD4Update ();
void MD4Final ();

/*
 ***********************************************************************
 ** End of md4.h                                                      **
 ******************************** (cut) ********************************


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 */





















































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/*
 ***********************************************************************
 ** md4.c -- the source code for MD4 routines                         **
 ** RSA Data Security, Inc. MD4 Message-Digest Algorithm              **
 ** Created: 2/17/90 RLR                                              **
 ** Revised: 1/91 SRD,AJ,BSK,JT Reference C Version                   **
 ***********************************************************************
 */

/*
 ***********************************************************************
 ** Copyright (C) 1990, 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.                                    **
 ***********************************************************************
 */

#include "md4.h"

/*
 ***********************************************************************
 **  Message-digest routines:                                         **
 **  To form the message digest for a message M                       **
 **    (1) Initialize a context buffer mdContext using MD4Init        **
 **    (2) Call MD4Update on mdContext and M                          **
 **    (3) Call MD4Final on mdContext                                 **
 **  The message digest is now in mdContext->digest[0...15]           **
 ***********************************************************************
 */

/* forward declaration */
static void Transform ();

static unsigned char PADDING[64] = {
  0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,


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  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};

/* F, G and H are basic MD4 functions: selection, majority, parity */
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))

/* ROTATE_LEFT rotates x left n bits */
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

/* FF, GG and HH are MD4 transformations for rounds 1, 2 and 3 */
/* Rotation is separate from addition to prevent recomputation */
#define FF(a, b, c, d, x, s) \
  {(a) += F ((b), (c), (d)) + (x); \
   (a) = ROTATE_LEFT ((a), (s));}
#define GG(a, b, c, d, x, s) \
  {(a) += G ((b), (c), (d)) + (x) + (UINT4)0x5A827999; \
   (a) = ROTATE_LEFT ((a), (s));}
#define HH(a, b, c, d, x, s) \
  {(a) += H ((b), (c), (d)) + (x) + (UINT4)0x6ED9EBA1; \
   (a) = ROTATE_LEFT ((a), (s));}

/* The routine MD4Init initializes the message-digest context
   mdContext. All fields are set to zero.
 */
void MD4Init (mdContext)
MD4_CTX *mdContext;
{
  mdContext->i[0] = mdContext->i[1] = (UINT4)0;

  /* Load magic initialization constants.
   */
  mdContext->buf[0] = (UINT4)0x67452301;
  mdContext->buf[1] = (UINT4)0xefcdab89;
  mdContext->buf[2] = (UINT4)0x98badcfe;
  mdContext->buf[3] = (UINT4)0x10325476;
}

/* The routine MD4Update updates the message-digest context to
   account for the presence of each of the characters inBuf[0..inLen-1]
   in the message whose digest is being computed.
 */
void MD4Update (mdContext, inBuf, inLen)
MD4_CTX *mdContext;
unsigned char *inBuf;
unsigned int inLen;


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{
  UINT4 in[16];
  int mdi;
  unsigned int i, ii;

  /* compute number of bytes mod 64 */
  mdi = (int)((mdContext->i[0] >> 3) & 0x3F);

  /* update number of bits */
  if ((mdContext->i[0] + ((UINT4)inLen << 3)) < mdContext->i[0])
    mdContext->i[1]++;
  mdContext->i[0] += ((UINT4)inLen << 3);
  mdContext->i[1] += ((UINT4)inLen >> 29);

  while (inLen--) {
    /* add new character to buffer, increment mdi */
    mdContext->in[mdi++] = *inBuf++;

    /* transform if necessary */
    if (mdi == 0x40) {
      for (i = 0, ii = 0; i < 16; i++, ii += 4)
        in[i] = (((UINT4)mdContext->in[ii+3]) << 24) |
                (((UINT4)mdContext->in[ii+2]) << 16) |
                (((UINT4)mdContext->in[ii+1]) << 8) |
                ((UINT4)mdContext->in[ii]);
      Transform (mdContext->buf, in);
      mdi = 0;
    }
  }
}

/* The routine MD4Final terminates the message-digest computation and
   ends with the desired message digest in mdContext->digest[0...15].
 */
void MD4Final (mdContext)
MD4_CTX *mdContext;
{
  UINT4 in[16];
  int mdi;
  unsigned int i, ii;
  unsigned int padLen;

  /* save number of bits */
  in[14] = mdContext->i[0];
  in[15] = mdContext->i[1];

  /* compute number of bytes mod 64 */
  mdi = (int)((mdContext->i[0] >> 3) & 0x3F);

  /* pad out to 56 mod 64 */
  padLen = (mdi < 56) ? (56 - mdi) : (120 - mdi);
  MD4Update (mdContext, PADDING, padLen);


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  /* append length in bits and transform */
  for (i = 0, ii = 0; i < 14; i++, ii += 4)
    in[i] = (((UINT4)mdContext->in[ii+3]) << 24) |
            (((UINT4)mdContext->in[ii+2]) << 16) |
            (((UINT4)mdContext->in[ii+1]) << 8) |
            ((UINT4)mdContext->in[ii]);
  Transform (mdContext->buf, in);

  /* store buffer in digest */
  for (i = 0, ii = 0; i < 4; i++, ii += 4) {
    mdContext->digest[ii] = (unsigned char)(mdContext->buf[i] & 0xFF);
    mdContext->digest[ii+1] =
      (unsigned char)((mdContext->buf[i] >> 8) & 0xFF);
    mdContext->digest[ii+2] =
      (unsigned char)((mdContext->buf[i] >> 16) & 0xFF);
    mdContext->digest[ii+3] =
      (unsigned char)((mdContext->buf[i] >> 24) & 0xFF);
  }
}

/* Basic MD4 step. Transforms buf based on in.
 */
static void Transform (buf, in)
UINT4 *buf;
UINT4 *in;
{
  UINT4 a = buf[0], b = buf[1], c = buf[2], d = buf[3];

  /* Round 1 */
  FF (a, b, c, d, in[ 0],  3);
  FF (d, a, b, c, in[ 1],  7);
  FF (c, d, a, b, in[ 2], 11);
  FF (b, c, d, a, in[ 3], 19);
  FF (a, b, c, d, in[ 4],  3);
  FF (d, a, b, c, in[ 5],  7);
  FF (c, d, a, b, in[ 6], 11);
  FF (b, c, d, a, in[ 7], 19);
  FF (a, b, c, d, in[ 8],  3);
  FF (d, a, b, c, in[ 9],  7);
  FF (c, d, a, b, in[10], 11);
  FF (b, c, d, a, in[11], 19);
  FF (a, b, c, d, in[12],  3);
  FF (d, a, b, c, in[13],  7);
  FF (c, d, a, b, in[14], 11);
  FF (b, c, d, a, in[15], 19);

  /* Round 2 */
  GG (a, b, c, d, in[ 0],  3);
  GG (d, a, b, c, in[ 4],  5);
  GG (c, d, a, b, in[ 8],  9);
  GG (b, c, d, a, in[12], 13);


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  GG (a, b, c, d, in[ 1],  3);
  GG (d, a, b, c, in[ 5],  5);
  GG (c, d, a, b, in[ 9],  9);
  GG (b, c, d, a, in[13], 13);
  GG (a, b, c, d, in[ 2],  3);
  GG (d, a, b, c, in[ 6],  5);
  GG (c, d, a, b, in[10],  9);
  GG (b, c, d, a, in[14], 13);
  GG (a, b, c, d, in[ 3],  3);
  GG (d, a, b, c, in[ 7],  5);
  GG (c, d, a, b, in[11],  9);
  GG (b, c, d, a, in[15], 13);

  /* Round 3 */
  HH (a, b, c, d, in[ 0],  3);
  HH (d, a, b, c, in[ 8],  9);
  HH (c, d, a, b, in[ 4], 11);
  HH (b, c, d, a, in[12], 15);
  HH (a, b, c, d, in[ 2],  3);
  HH (d, a, b, c, in[10],  9);
  HH (c, d, a, b, in[ 6], 11);
  HH (b, c, d, a, in[14], 15);
  HH (a, b, c, d, in[ 1],  3);
  HH (d, a, b, c, in[ 9],  9);
  HH (c, d, a, b, in[ 5], 11);
  HH (b, c, d, a, in[13], 15);
  HH (a, b, c, d, in[ 3],  3);
  HH (d, a, b, c, in[11],  9);
  HH (c, d, a, b, in[ 7], 11);
  HH (b, c, d, a, in[15], 15);

  buf[0] += a;
  buf[1] += b;
  buf[2] += c;
  buf[3] += d;
}

/*
 ***********************************************************************
 ** End of md4.c                                                      **
 ******************************** (cut) ********************************
 */












Rivest and Dusse                                               [Page 15]
INTERNET-DRAFT      The MD4 Message-Digest Algorithm         1 July 1991


/*
 ***********************************************************************
 ** md4driver.c -- sample test routines                               **
 ** RSA Data Security, Inc. MD4 Message-Digest Algorithm              **
 ** Created: 2/16/90 RLR                                              **
 ** Updated: 1/91 SRD                                                 **
 ***********************************************************************
 */

/*
 ***********************************************************************
 ** Copyright (C) 1990, RSA Data Security, Inc. All rights reserved.  **
 **                                                                   **
 ** 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.                                    **
 ***********************************************************************
 */

#include <stdio.h>
#include <sys/types.h>
#include <time.h>
#include <string.h>
#include "md4.h"

/* Prints message digest buffer in mdContext as 32 hexadecimal digits.
   Order is from low-order byte to high-order byte of digest.
   Each byte is printed with high-order hexadecimal digit first.
 */
static void MDPrint (mdContext)
MD4_CTX *mdContext;
{
  int i;

  for (i = 0; i < 16; i++)
    printf ("%02x", mdContext->digest[i]);
}

/* size of test block */
#define TEST_BLOCK_SIZE 1000

/* number of blocks to process */
#define TEST_BLOCKS 10000

/* number of test bytes = TEST_BLOCK_SIZE * TEST_BLOCKS */
static long TEST_BYTES = (long)TEST_BLOCK_SIZE * (long)TEST_BLOCKS;

/* A time trial routine, to measure the speed of MD4.


Rivest and Dusse                                               [Page 16]
INTERNET-DRAFT      The MD4 Message-Digest Algorithm         1 July 1991


   Measures wall time required to digest TEST_BLOCKS * TEST_BLOCK_SIZE
   characters.
 */
static void MDTimeTrial ()
{
  MD4_CTX mdContext;
  time_t endTime, startTime;
  unsigned char data[TEST_BLOCK_SIZE];
  unsigned int i;

  /* initialize test data */
  for (i = 0; i < TEST_BLOCK_SIZE; i++)
    data[i] = (unsigned char)(i & 0xFF);

  /* start timer */
  printf ("MD4 time trial. Processing %ld characters...\n", TEST_BYTES);
  time (&startTime);

  /* digest data in TEST_BLOCK_SIZE byte blocks */
  MD4Init (&mdContext);
  for (i = TEST_BLOCKS; i > 0; i--)
    MD4Update (&mdContext, data, TEST_BLOCK_SIZE);
  MD4Final (&mdContext);

  /* stop timer, get time difference */
  time (&endTime);
  MDPrint (&mdContext);
  printf (" is digest of test input.\n");
  printf
    ("Seconds to process test input: %ld\n", (long)(endTime-startTime));
  printf
    ("Characters processed per second: %ld\n",
     TEST_BYTES/(endTime-startTime));
}

/* Computes the message digest for string inString.
   Prints out message digest, a space, the string (in quotes) and a
   carriage return.
 */
static void MDString (inString)
char *inString;
{
  MD4_CTX mdContext;
  unsigned int len = strlen (inString);

  MD4Init (&mdContext);
  MD4Update (&mdContext, inString, len);
  MD4Final (&mdContext);
  MDPrint (&mdContext);
  printf (" \"%s\"\n", inString);
}



Rivest and Dusse                                               [Page 17]
INTERNET-DRAFT      The MD4 Message-Digest Algorithm         1 July 1991


/* Computes the message digest for a specified file.
   Prints out message digest, a space, the file name, and a carriage
   return.
 */
static void MDFile (filename)
char *filename;
{
  FILE *inFile = fopen (filename, "rb");
  MD4_CTX mdContext;
  int bytes;
  unsigned char data[1024];

  if (inFile == NULL) {
    printf ("%s can't be opened.\n", filename);
    return;
  }

  MD4Init (&mdContext);
  while ((bytes = fread (data, 1, 1024, inFile)) != 0)
    MD4Update (&mdContext, data, bytes);
  MD4Final (&mdContext);
  MDPrint (&mdContext);
  printf (" %s\n", filename);
  fclose (inFile);
}

/* Writes the message digest of the data from stdin onto stdout,
   followed by a carriage return.
 */
static void MDFilter ()
{
  MD4_CTX mdContext;
  int bytes;
  unsigned char data[16];

  MD4Init (&mdContext);
  while ((bytes = fread (data, 1, 16, stdin)) != 0)
    MD4Update (&mdContext, data, bytes);
  MD4Final (&mdContext);
  MDPrint (&mdContext);
  printf ("\n");
}

/* Runs a standard suite of test data.
 */
static void MDTestSuite ()
{
  printf ("MD4 test suite results:\n");
  MDString ("");
  MDString ("a");
  MDString ("abc");
  MDString ("message digest");


Rivest and Dusse                                               [Page 18]
INTERNET-DRAFT      The MD4 Message-Digest Algorithm         1 July 1991


  MDString ("abcdefghijklmnopqrstuvwxyz");
  MDString
    ("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789");
  MDString
    ("1234567890123456789012345678901234567890\
1234567890123456789012345678901234567890");
  /* Contents of file foo are "abc" */
  MDFile ("foo");
}

void main (argc, argv)
int argc;
char *argv[];
{
  int i;

  /* For each command line argument in turn:
  ** filename          -- prints message digest and name of file
  ** -sstring          -- prints message digest and contents of string
  ** -t                -- prints time trial statistics for 10M
                          characters
  ** -x                -- execute a standard suite of test data
  ** (no args)         -- writes messages digest of stdin onto stdout
  */
  if (argc == 1)
    MDFilter ();
  else
    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 ();
      else MDFile (argv[i]);
}

/*
 ***********************************************************************
 ** End of md4driver.c                                                **
 ******************************** (cut) ********************************
 */












Rivest and Dusse                                               [Page 19]
INTERNET-DRAFT      The MD4 Message-Digest Algorithm         1 July 1991


------------------------------------------------------------------------
-- Sample session output obtained by running md4driver test suite     --
------------------------------------------------------------------------

MD4 test suite results:
31d6cfe0d16ae931b73c59d7e0c089c0 ""
bde52cb31de33e46245e05fbdbd6fb24 "a"
a448017aaf21d8525fc10ae87aa6729d "abc"
d9130a8164549fe818874806e1c7014b "message digest"
d79e1c308aa5bbcdeea8ed63df412da9 "abcdefghijklmnopqrstuvwxyz"
043f8582f241db351ce627e153e7f0e4 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijk\
lmnopqrstuvwxyz0123456789"
e33b4ddc9c38f2199c3e7b164fcc0536 "1234567890123456789012345678901234567\
8901234567890123456789012345678901234567890"
a448017aaf21d8525fc10ae87aa6729d foo

------------------------------------------------------------------------
-- End of sample session                                              --
-------------------------------- (cut) ---------------------------------



































Rivest and Dusse                                               [Page 20]