if (inputLen >= partLen) {
    MD2_memcpy
      ((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;
  }
  else
    i = 0;

  /* Buffer remaining input */
  MD2_memcpy
    ((POINTER)&context->buffer[index], (POINTER)&input[i],
     inputLen-i);
}

/* MD2 finalization. Ends an MD2 message-digest operation, writing the
     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 checksum
     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;
  }



Kaliski                                                        [Page 10]

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.c

/* MDDRIVER.C - test driver for MD2, MD4 and MD5
 */

/* Copyright (C) 1990-2, RSA Data Security, Inc. Created 1990. All
   rights reserved.




Kaliski                                                        [Page 11]

RFC 1319              MD2 Message-Digest Algorithm            April 1992


   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.
 */

/* The following makes MD default to MD5 if it has not already been
     defined with C compiler flags.
 */
#ifndef MD
#define MD MD5
#endif

#include <stdio.h>
#include <time.h>
#include <string.h>
#include "global.h"
#if MD == 2
#include "md2.h"
#endif
#if MD == 4
#include "md4.h"
#endif
#if MD == 5
#include "md5.h"
#endif

/* 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_CTX
#define MDInit MD2Init
#define MDUpdate MD2Update
#define MDFinal MD2Final
#endif



Kaliski                                                        [Page 12]

RFC 1319              MD2 Message-Digest Algorithm            April 1992


#if MD == 4
#define MD_CTX MD4_CTX
#define MDInit MD4Init
#define MDUpdate MD4Update
#define MDFinal MD4Final
#endif
#if MD == 5
#define MD_CTX MD5_CTX
#define MDInit MD5Init
#define MDUpdate MD5Update
#define MDFinal MD5Final
#endif

/* Main driver.

   Arguments (may be any combination):
     -sstring - digests string
     -t       - runs time trial
     -x       - runs test script
     filename - digests file
     (none)   - digests standard input
 */
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 ();
      else
        MDFile (argv[i]);
  else
    MDFilter ();

  return (0);
}

/* Digests a string and prints the result.
 */
static void MDString (string)
char *string;



Kaliski                                                        [Page 13]

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-byte
     blocks.
 */
static void MDTimeTrial ()
{
  MD_CTX context;
  time_t endTime, startTime;
  unsigned char block[TEST_BLOCK_LEN], digest[16];
  unsigned int i;

  printf
    ("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


  printf
    ("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");
  MDString
    ("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789");
  MDString
    ("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");
  }
}



Kaliski                                                        [Page 15]

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 suite

   The MD2 test suite (driver option "-x") should print the following
   results:

MD2 test suite:
MD2 ("") = 8350e5a3e24c153df2275c9f80692773
MD2 ("a") = 32ec01ec4a6dac72c0ab96fb34c0b5d1
MD2 ("abc") = da853b0d3f88d99b30283a69e6ded6bb
MD2 ("message digest") = ab4f496bfb2a530b219ff33031fe06b0
MD2 ("abcdefghijklmnopqrstuvwxyz") = 4e8ddff3650292ab5a4108c3aa47940b
MD2 ("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789") =
da33def2a42df13975352846c30338cd
MD2 ("123456789012345678901234567890123456789012345678901234567890123456
78901234567890") = d5976f79d83d3a0dc9806c3c66f3efd8








Kaliski                                                        [Page 16]

RFC 1319              MD2 Message-Digest Algorithm            April 1992


Security Considerations

   The level of security discussed in this memo is considered to be
   sufficient for implementing very high security hybrid digital
   signature schemes based on MD2 and a public-key cryptosystem.

Author's Address

   Burton S. Kaliski Jr.
   RSA Laboratories (a division of RSA Data Security, Inc.)
   10 Twin Dolphin Drive
   Redwood City, CA  94065

   Phone: (415) 595-8782
   FAX: (415) 595-4126
   EMail: burt@rsa.com



































Kaliski                                                        [Page 17]