Kerberos v4 authentication patch for lynx-2.7.1
-----------------------------------------------

To use this patch:

1. Apply patch to lynx-2.7.1 distribution. 

	cd WWW/Library/Implementation/ ; patch < lynx271-krb4.patch

2. Add the location of the Kerberos libs to SITE_LIBS in the Makefile:

	-L/usr/kerberos/lib -lkrb -ldes

3. Add the following definition and the location of your Kerberos
   includes to SITE_LYDEFS in the Makefile:

	-DHAVE_KERBEROS4 -I/usr/kerberos/include

4. Follow the rest of the instructions in INSTALLATION.

More information on the protocol used and the server support is
available at http://www-personal.umich.edu/~dugsong/klynx/

Dug Song <dugsong@UMICH.EDU>


diff -c -r CommonMakefile~ CommonMakefile
*** CommonMakefile~	Sat May 24 10:59:44 1997
--- CommonMakefile	Tue Jun 10 13:18:56 1997
***************
*** 86,92 ****
  	$(LOB)/HTAAUtil.o $(LOB)/HTAAServ.o $(LOB)/HTAABrow.o \
  	$(LOB)/HTAAFile.o $(LOB)/HTPasswd.o $(LOB)/HTGroup.o  \
  	$(LOB)/HTACL.o    $(LOB)/HTAuth.o   $(LOB)/HTAAProt.o \
! 	$(LOB)/HTAssoc.o  $(LOB)/HTLex.o    $(LOB)/HTUU.o
  
  CFILES = $(CMN)HTParse.c $(CMN)HTAccess.c $(CMN)HTTP.c $(CMN)HTFile.c \
          $(CMN)HTBTree.c \
--- 86,93 ----
  	$(LOB)/HTAAUtil.o $(LOB)/HTAAServ.o $(LOB)/HTAABrow.o \
  	$(LOB)/HTAAFile.o $(LOB)/HTPasswd.o $(LOB)/HTGroup.o  \
  	$(LOB)/HTACL.o    $(LOB)/HTAuth.o   $(LOB)/HTAAProt.o \
! 	$(LOB)/HTAssoc.o  $(LOB)/HTLex.o    $(LOB)/HTUU.o \
! 	$(LOB)/HTMD5.o
  
  CFILES = $(CMN)HTParse.c $(CMN)HTAccess.c $(CMN)HTTP.c $(CMN)HTFile.c \
          $(CMN)HTBTree.c \
***************
*** 102,108 ****
  	$(CMN)HTAAUtil.c $(CMN)HTAAServ.c $(CMN)HTAABrow.c \
  	$(CMN)HTAAFile.c $(CMN)HTPasswd.c $(CMN)HTGroup.c  \
  	$(CMN)HTACL.c    $(CMN)HTAuth.c   $(CMN)HTAAProt.c \
! 	$(CMN)HTAssoc.c  $(CMN)HTLex.c    $(CMN)HTUU.c
  
  HFILES = $(CMN)HTParse.h $(CMN)HTAccess.h $(CMN)HTTP.h $(CMN)HTFile.h \
  	$(CMN)HTBTree.h $(CMN)HTFTP.h $(CMN)HTTCP.h \
--- 103,110 ----
  	$(CMN)HTAAUtil.c $(CMN)HTAAServ.c $(CMN)HTAABrow.c \
  	$(CMN)HTAAFile.c $(CMN)HTPasswd.c $(CMN)HTGroup.c  \
  	$(CMN)HTACL.c    $(CMN)HTAuth.c   $(CMN)HTAAProt.c \
! 	$(CMN)HTAssoc.c  $(CMN)HTLex.c    $(CMN)HTUU.c \
! 	$(CMN)HTMD5.c
  
  HFILES = $(CMN)HTParse.h $(CMN)HTAccess.h $(CMN)HTTP.h $(CMN)HTFile.h \
  	$(CMN)HTBTree.h $(CMN)HTFTP.h $(CMN)HTTCP.h \
***************
*** 292,297 ****
--- 294,302 ----
  
  #	Access Authorization
  
+ $(LOB)/HTMD5.o : $(OE) $(CMN)HTMD5.c $(CMN)HTMD5.h
+ 	$(CC) -c -o $@ $(CFLAGS2) $(CMN)HTMD5.c
+ 
  $(LOB)/HTAAUtil.o : $(OE) $(CMN)HTAAUtil.c $(CMN)HTAAUtil.h \
  	 $(CMN)HTUtils.h $(CMN)HTString.h
  	$(CC) -c -o $@ $(CFLAGS2) $(CMN)HTAAUtil.c
diff -c -r HTAABrow.c~ HTAABrow.c
*** HTAABrow.c~	Sat May 24 10:59:39 1997
--- HTAABrow.c	Tue Jun 10 13:36:35 1997
***************
*** 57,62 ****
--- 57,65 ----
  #include "HTAssoc.h"		/* Assoc list			*/
  #include "HTAABrow.h"		/* Implemented here		*/
  #include "HTUU.h"		/* Uuencoding and uudecoding	*/
+ #ifdef HAVE_KERBEROS4
+ #include <krb.h>
+ #endif /* HAVE_KERBEROS4 */	/* Kerberos v4 routines		*/
  
  #include "LYLeaks.h"
  
***************
*** 516,522 ****
--- 519,604 ----
      return realm;
  }
  
+ #ifdef HAVE_KERBEROS4
+ #define PUTLONG(l, cp) { \
+   register unsigned int t_l = (unsigned int)(l); \
+   register unsigned char *t_cp = (unsigned char*)(cp); \
+   *t_cp++ = t_l >> 24; \
+   *t_cp++ = t_l >> 16; \
+   *t_cp++ = t_l >> 8; \
+   *t_cp   = t_l; \
+   (cp) += 4; \
+ }
  
+ /* Base-64 encode Kerberos v4 service ticket. */
+ PRIVATE int tkt_to_radix ARGS2(KTEXT, auth,
+ 			       char *, buf)
+ {
+   char *p;
+   long len;
+   char temp[2048];
+   
+   p = temp;
+   *p++ = 1; /* version */
+   PUTLONG(auth->length, p);
+   memcpy(p, auth->dat, auth->length);
+   p += auth->length;
+   len = p-temp;
+   HTUU_encode((unsigned char *)temp, len, buf);
+   
+   return len;
+ }
+ 
+ /*
+   Kerberos v4 authentication.
+   See http://www-personal.umich.edu/~dugsong/kapache/ for info.
+ */
+ PRIVATE char *compose_krb4_auth_string ARGS3(HTAAScheme, scheme,
+ 					     HTAASetup *, setup,
+ 					     CONST char *, docname)
+ {
+   KTEXT_ST auth;
+   CREDENTIALS cred;
+   char *princ, *url;
+   char service[ANAME_SZ];
+   char inst[INST_SZ];
+   char realm[REALM_SZ];
+   char auth_line[1024];
+   char digest[33];
+   
+   FREE(compose_auth_stringResult);
+   
+   if (scheme != HTAA_KERBEROS_V4 || !setup || !setup->scheme_specifics ||
+       !setup->scheme_specifics[scheme] || !setup->server ||
+       !(princ = HTAssocList_lookup(setup->scheme_specifics[scheme], "realm")))
+     return NULL;
+   
+   *service = '\0'; *inst = '\0'; *realm = '\0';
+   if (!princ || kname_parse(service, inst, realm, princ) != KSUCCESS ||
+       !*service || !*inst || !*realm) {
+     return NULL;
+   }
+   if ((krb_mk_req(&auth, service, inst, realm, 0L) != KSUCCESS) ||
+       (krb_get_cred(service, inst, realm, &cred) != KSUCCESS) ||
+       !tkt_to_radix(&auth, auth_line))
+     return NULL;
+   
+   url = (char *)calloc(1, strlen(docname)+1+1);
+   strcpy(url, "/"); strcat(url, docname);
+   hmac_md5(url, strlen(url), cred.session, DES_KEY_SZ, digest);
+   FREE(url);
+   
+   if (!(compose_auth_stringResult =
+ 	(char*)calloc(1, strlen(auth_line) + 33 + 22 + 1)))
+     outofmem(__FILE__, "compose_auth_string");
+ 
+   sprintf(compose_auth_stringResult,
+ 	  "ticket=\"%s\" checksum=\"%s\"", auth_line, digest);
+   
+   return compose_auth_stringResult;
+ }
+ #endif /* HAVE_KERBEROS4 */
+ 
  /***************** Basic and Pubkey Authentication ************************/
  
  /* PRIVATE						compose_auth_string()
***************
*** 840,846 ****
  	auth_string = compose_auth_string(scheme, current_setup);
  	break;
        case HTAA_KERBEROS_V4:
! 	/* OTHER AUTHENTICATION ROUTINES ARE CALLED HERE */
        default:
  	{
  	    char msg[100];
--- 922,932 ----
  	auth_string = compose_auth_string(scheme, current_setup);
  	break;
        case HTAA_KERBEROS_V4:
! #ifdef HAVE_KERBEROS4
! 	auth_string =
! 	  compose_krb4_auth_string(scheme, current_setup, docname);
! 	break;
! #endif /* HAVE_KERBEROS4 */
        default:
  	{
  	    char msg[100];
diff -c -r HTMD5.c~ HTMD5.c
*** HTMD5.c~	Tue Jun 10 16:48:36 1997
--- HTMD5.c	Tue Jun 10 13:19:42 1997
***************
*** 0 ****
--- 1,413 ----
+ /*
+  * This is work is derived from material Copyright RSA Data Security, Inc.
+  *
+  * The RSA copyright statement and Licence for that original material is
+  * included below. This is followed by the Apache copyright statement and
+  * licence for the modifications made to that material.
+  */
+ 
+ /* MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
+  */
+ 
+ /* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
+ rights reserved.
+ 
+ License to copy and use this software is granted provided that it
+ is identified as the "RSA Data Security, Inc. MD5 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. MD5 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.
+  */
+ 
+ /* ====================================================================
+  * Copyright (c) 1996,1997 The Apache Group.  All rights reserved.
+  *
+  * Redistribution and use in source and binary forms, with or without
+  * modification, are permitted provided that the following conditions
+  * are met:
+  *
+  * 1. Redistributions of source code must retain the above copyright
+  *    notice, this list of conditions and the following disclaimer. 
+  *
+  * 2. Redistributions in binary form must reproduce the above copyright
+  *    notice, this list of conditions and the following disclaimer in
+  *    the documentation and/or other materials provided with the
+  *    distribution.
+  *
+  * 3. All advertising materials mentioning features or use of this
+  *    software must display the following acknowledgment:
+  *    "This product includes software developed by the Apache Group
+  *    for use in the Apache HTTP server project (http://www.apache.org/)."
+  *
+  * 4. The names "Apache Server" and "Apache Group" must not be used to
+  *    endorse or promote products derived from this software without
+  *    prior written permission.
+  *
+  * 5. Redistributions of any form whatsoever must retain the following
+  *    acknowledgment:
+  *    "This product includes software developed by the Apache Group
+  *    for use in the Apache HTTP server project (http://www.apache.org/)."
+  *
+  * THIS SOFTWARE IS PROVIDED BY THE APACHE GROUP ``AS IS'' AND ANY
+  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE APACHE GROUP OR
+  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+  * OF THE POSSIBILITY OF SUCH DAMAGE.
+  * ====================================================================
+  *
+  * This software consists of voluntary contributions made by many
+  * individuals on behalf of the Apache Group and was originally based
+  * on public domain software written at the National Center for
+  * Supercomputing Applications, University of Illinois, Urbana-Champaign.
+  * For more information on the Apache Group and the Apache HTTP server
+  * project, please see <http://www.apache.org/>.
+  *
+  */
+ 
+ #include <string.h>
+ 
+ #include "HTMD5.h"
+ 
+ /* Constants for MD5Transform routine.
+  */
+ 
+ #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 HT_MD5Transform(UINT4 state[4], const unsigned char block[64]);
+ static void Encode(unsigned char *output, const UINT4 *input,
+ 		   unsigned int len);
+ static void Decode(UINT4 *output, const unsigned char *input,
+ 		   unsigned int len);
+ 
+ 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)); \
+  (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
+ HT_MD5Init(HT_MD5_CTX *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-digest
+   operation, processing another message block, and updating the
+   context.
+  */
+ void
+ HT_MD5Update(HT_MD5_CTX *context, const unsigned char *input, unsigned int inputLen)
+ {
+     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)) < ((UINT4)inputLen << 3))
+ 	context->count[1]++;
+     context->count[1] += (UINT4)inputLen >> 29;
+ 
+     partLen = 64 - index;
+ 
+   /* Transform as many times as possible. */
+     if (inputLen >= partLen)
+     {
+ 	memcpy(&context->buffer[index], input, partLen);
+ 	HT_MD5Transform(context->state, context->buffer);
+ 
+ 	for (i = partLen; i + 63 < inputLen; i += 64)
+ 	    HT_MD5Transform(context->state, &input[i]);
+ 
+ 	index = 0;
+     }
+     else
+ 	i = 0;
+ 
+   /* Buffer remaining input */
+     memcpy(&context->buffer[index], &input[i], inputLen-i);
+ }
+ 
+ /* MD5 finalization. Ends an MD5 message-digest operation, writing the
+   the message digest and zeroizing the context.
+  */
+ void
+ HT_MD5Final(unsigned char digest[16], HT_MD5_CTX *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);
+     HT_MD5Update(context, PADDING, padLen);
+ 
+   /* Append length (before padding) */
+     HT_MD5Update(context, bits, 8);
+ 
+   /* Store state in digest */
+     Encode(digest, context->state, 16);
+ 
+   /* Zeroize sensitive information. */
+     memset(context, 0, sizeof (*context));
+ }
+ 
+ /* MD5 basic transformation. Transforms state based on block. */
+ static void
+ HT_MD5Transform(UINT4 state[4], const 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 */
+     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. */
+     memset(x, 0, sizeof (x));
+ }
+ 
+ /* Encodes input (UINT4) into output (unsigned char). Assumes len is
+   a multiple of 4.
+  */
+ static void
+ Encode(unsigned char *output, const UINT4 *input, unsigned int len)
+ {
+     unsigned int i, j;
+     UINT4 k;
+ 
+     for (i = 0, j = 0; j < len; i++, j += 4)
+     {
+ 	k = input[i];
+ 	output[j] = (unsigned char)(k & 0xff);
+ 	output[j+1] = (unsigned char)((k >> 8) & 0xff);
+ 	output[j+2] = (unsigned char)((k >> 16) & 0xff);
+ 	output[j+3] = (unsigned char)((k >> 24) & 0xff);
+     }
+ }
+ 
+ /* Decodes input (unsigned char) into output (UINT4). Assumes len is
+   a multiple of 4.
+  */
+ static void
+ Decode(UINT4 *output, const 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);
+ }
+ 
+ #ifdef HAVE_KERBEROS4
+ /* Our own HMAC-MD5 function based on RFC 2104's hmac_md5(). */
+ void hmac_md5(unsigned char *text, int tlen,
+ 	       unsigned char *key, int klen, char *dest)
+ {
+   HT_MD5_CTX context; 
+   unsigned char k_ipad[65];	/* inner padding - key XORd with ipad */
+   unsigned char k_opad[65];	/* outer padding - key XORd with opad */
+   unsigned char tk[16], hash[16];
+   char *r, result[33];
+   int i;
+ 
+   /* fprintf(stderr,"md5: Got text %s, len %s", text ? (char *)text : "NULL", tlen);*/
+   /* if key is longer than 64 bytes reset it to key=MD5(key) */
+   if (klen > 64) {
+     HT_MD5_CTX      tctx;
+     HT_MD5Init(&tctx); 
+     HT_MD5Update(&tctx, key, klen); 
+     HT_MD5Final(tk, &tctx); 
+     key = tk; 
+     klen = 16; 
+   }
+   /* the HMAC_MD5 transform looks like:
+      
+      MD5(K XOR opad, MD5(K XOR ipad, text))
+      
+      where K is an n byte key
+      ipad is the byte 0x36 repeated 64 times
+      opad is the byte 0x5c repeated 64 times
+      and text is the data being protected */
+   
+   /* start out by storing key in pads */
+   bzero( k_ipad, sizeof k_ipad); bzero( k_opad, sizeof k_opad);
+   bcopy( key, k_ipad, klen); bcopy( key, k_opad, klen);
+   
+   /* XOR key with ipad and opad values */
+   for (i=0; i<64; i++) {
+     k_ipad[i] ^= 0x36;
+     k_opad[i] ^= 0x5c;
+   }
+   /* perform inner MD5 */
+   HT_MD5Init(&context);			/* init context for 1st pass */
+   HT_MD5Update(&context, k_ipad, 64);	/* start with inner pad */
+   HT_MD5Update(&context, text, tlen);	/* then text of datagram */
+   HT_MD5Final(hash, &context);		/* finish up 1st pass */
+ 
+   /* perform outer MD5 */
+   HT_MD5Init(&context);			/* init context for 2nd pass */
+   HT_MD5Update(&context, k_opad, 64);	/* start with outer pad */
+   HT_MD5Update(&context, hash, 16);	/* then results of 1st hash */
+   HT_MD5Final(hash, &context);		/* finish up 2nd pass */
+ 
+   for (i=0, r=result; i<16; i++, r+=2)
+     sprintf(r, "%02x", hash[i]);
+   *r = '\0';
+   strncpy(dest, result, 32);
+ }
+ #endif /* HAVE_KERBEROS4 */
diff -c -r HTMD5.h~ HTMD5.h
*** HTMD5.h~	Tue Jun 10 16:48:37 1997
--- HTMD5.h	Tue Jun 10 16:37:07 1997
***************
*** 0 ****
--- 1,103 ----
+ /*
+  * This is work is derived from material Copyright RSA Data Security, Inc.
+  *
+  * The RSA copyright statement and Licence for that original material is
+  * included below. This is followed by the Apache copyright statement and
+  * licence for the modifications made to that material.
+  */
+ 
+ /* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
+ rights reserved.
+ 
+ License to copy and use this software is granted provided that it
+ is identified as the "RSA Data Security, Inc. MD5 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. MD5 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.
+  */
+ 
+ /* ====================================================================
+  * Copyright (c) 1996,1997 The Apache Group.  All rights reserved.
+  *
+  * Redistribution and use in source and binary forms, with or without
+  * modification, are permitted provided that the following conditions
+  * are met:
+  *
+  * 1. Redistributions of source code must retain the above copyright
+  *    notice, this list of conditions and the following disclaimer. 
+  *
+  * 2. Redistributions in binary form must reproduce the above copyright
+  *    notice, this list of conditions and the following disclaimer in
+  *    the documentation and/or other materials provided with the
+  *    distribution.
+  *
+  * 3. All advertising materials mentioning features or use of this
+  *    software must display the following acknowledgment:
+  *    "This product includes software developed by the Apache Group
+  *    for use in the Apache HTTP server project (http://www.apache.org/)."
+  *
+  * 4. The names "Apache Server" and "Apache Group" must not be used to
+  *    endorse or promote products derived from this software without
+  *    prior written permission.
+  *
+  * 5. Redistributions of any form whatsoever must retain the following
+  *    acknowledgment:
+  *    "This product includes software developed by the Apache Group
+  *    for use in the Apache HTTP server project (http://www.apache.org/)."
+  *
+  * THIS SOFTWARE IS PROVIDED BY THE APACHE GROUP ``AS IS'' AND ANY
+  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE APACHE GROUP OR
+  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+  * OF THE POSSIBILITY OF SUCH DAMAGE.
+  * ====================================================================
+  *
+  * This software consists of voluntary contributions made by many
+  * individuals on behalf of the Apache Group and was originally based
+  * on public domain software written at the National Center for
+  * Supercomputing Applications, University of Illinois, Urbana-Champaign.
+  * For more information on the Apache Group and the Apache HTTP server
+  * project, please see <http://www.apache.org/>.
+  *
+  */
+ 
+ 
+ /* MD5.H - header file for MD5C.C */
+ 
+ /* UINT4 defines a four byte word */
+ typedef unsigned int UINT4;
+ 
+ /* 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 */
+ } HT_MD5_CTX;
+ 
+ extern void HT_MD5Init(HT_MD5_CTX *context);
+ extern void HT_MD5Update(HT_MD5_CTX *context, const unsigned char *input,
+ 		      unsigned int inputLen);
+ extern void HT_MD5Final(unsigned char digest[16], HT_MD5_CTX *context);
+ #ifdef HAVE_KERBEROS4
+ extern void hmac_md5(unsigned char *text, int tlen,
+ 		     unsigned char *key, int klen, char *dest);
+ #endif /* HAVE_KERBEROS4 */