[PATCH] CRC 32, CRC 32 a'la RFC 1510, CRC 24 a'la RFC 2440

Simon Josefsson jas@extundo.com
Mon, 20 Jan 2003 20:32:45 +0100


Werner Koch <wk@gnupg.org> writes:

>> On a similar topic, what do you think about adding a CRC32 "message
>> digest"?  It might be useful to have, even though it is not the most
>> secure message digest, and the libgcrypt framework fits rather nicely.
>
> Doing CRC32 is pretty easy to code, so there is no real advantage.
> OTOH, I agree that it fits perfectly into the message digest framework
> and it is useful for certain applications.

I wasn't sure you wanted it, but the manual now says:

,----
| For convenience reasons, we plan to integrate simple CRC algorithms too
`----

so I guess that should be fixed.  The following is barely tested at
all on ia32 only.

PS. My key derivation work has been distracted by other things, but
    maybe soon.

Index: AUTHORS
===================================================================
RCS file: /cvs/gnupg/libgcrypt/AUTHORS,v
retrieving revision 1.38
diff -u -p -r1.38 AUTHORS
--- AUTHORS	21 Dec 2002 15:54:49 -0000	1.38
+++ AUTHORS	20 Jan 2003 19:29:02 -0000
@@ -50,7 +50,8 @@ Assigns past and future changes.
 twoaday@freakmail.de
 
 LIBGCRYPT Simon Josefsson       2002-10-25
-Assigns past and future changes to FSF (cipher/md4.c, CTS flag)
+Assigns past and future changes to FSF (cipher/{md4,crc}.c, CTS flag,
+self test improvements)
 simon@josefsson.org
 
 
Index: ChangeLog
===================================================================
RCS file: /cvs/gnupg/libgcrypt/ChangeLog,v
retrieving revision 1.115
diff -u -p -r1.115 ChangeLog
--- ChangeLog	20 Jan 2003 10:30:23 -0000	1.115
+++ ChangeLog	20 Jan 2003 19:29:02 -0000
@@ -1,3 +1,7 @@
+2003-01-20  Simon Josefsson  <jas@extundo.com>
+
+	* configure.ac (MODULES_IN_CIPHER): Add crc.
+
 2003-01-20  Werner Koch  <wk@gnupg.org>
 
 	Released 1.1.12.
Index: NEWS
===================================================================
RCS file: /cvs/gnupg/libgcrypt/NEWS,v
retrieving revision 1.26
diff -u -p -r1.26 NEWS
--- NEWS	20 Jan 2003 16:58:05 -0000	1.26
+++ NEWS	20 Jan 2003 19:29:02 -0000
@@ -1,6 +1,9 @@
 Noteworthy changes in version 1.1.13 (unreleased)
 -------------------------------------------------
 
+ * CRC-32, CRC-32 a'la RFC 1510, CRC-24 a'la RFC 2440 is now
+   supported.
+
  * SHA-256 is now supported.
 
 Noteworthy changes in version 1.1.12 (2003-01-20)
Index: configure.ac
===================================================================
RCS file: /cvs/gnupg/libgcrypt/configure.ac,v
retrieving revision 1.30
diff -u -p -r1.30 configure.ac
--- configure.ac	20 Jan 2003 16:58:05 -0000	1.30
+++ configure.ac	20 Jan 2003 19:29:02 -0000
@@ -71,7 +71,7 @@ AC_SUBST(VERSION)
 AC_DEFINE_UNQUOTED(PACKAGE, "$PACKAGE", [Name of this package])
 AC_DEFINE_UNQUOTED(VERSION, "$VERSION", [Version of this package])
 
-static_modules="sha1 sha256 md4 md5 rmd160"
+static_modules="sha1 sha256 md4 md5 rmd160 crc"
 static_random_module=""
 
 AC_PROG_AWK
Index: cipher/ChangeLog
===================================================================
RCS file: /cvs/gnupg/libgcrypt/cipher/ChangeLog,v
retrieving revision 1.143
diff -u -p -r1.143 ChangeLog
--- cipher/ChangeLog	20 Jan 2003 16:58:10 -0000	1.143
+++ cipher/ChangeLog	20 Jan 2003 19:29:02 -0000
@@ -1,3 +1,9 @@
+2003-01-20  Simon Josefsson  <jas@extundo.com>
+
+	* crc.c: New.
+	* Makefile.am (EXTRA_PROGRAMS, EXTRA_crc_SOURCES): Add crc.c.
+	* md.c (gcry_md_get_algo_dlen): Add values for CRC.
+
 2003-01-20  Werner Koch  <wk@gnupg.org>
 
 	* sha256.c: New.
Index: cipher/Makefile.am
===================================================================
RCS file: /cvs/gnupg/libgcrypt/cipher/Makefile.am,v
retrieving revision 1.68
diff -u -p -r1.68 Makefile.am
--- cipher/Makefile.am	20 Jan 2003 16:58:10 -0000	1.68
+++ cipher/Makefile.am	20 Jan 2003 19:29:02 -0000
@@ -28,7 +28,7 @@ noinst_LTLIBRARIES = libcipher.la
 
 
 # The configure script greps the module names from the EXTRA_PROGRAMS line
-EXTRA_PROGRAMS = rndlinux rndunix rndegd rndw32 sha1 sha256 rmd160 md4 md5 tiger
+EXTRA_PROGRAMS = rndlinux rndunix rndegd rndw32 sha1 sha256 rmd160 md4 md5 tiger crc
 
 EXTRA_rndlinux_SOURCES = rndlinux.c
 EXTRA_rndunix_SOURCES = rndunix.c
@@ -40,6 +40,7 @@ EXTRA_rmd160_SOURCES = rmd160.c
 EXTRA_sha1_SOURCES = sha1.c
 EXTRA_sha256_SOURCES = sha256.c
 EXTRA_tiger_SOURCES = tiger.c
+EXTRA_crc_SOURCES = crc.c
 
 
 libcipher_la_LDFLAGS =
Index: cipher/crc.c
===================================================================
RCS file: cipher/crc.c
diff -N cipher/crc.c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ cipher/crc.c	20 Jan 2003 19:29:02 -0000
@@ -0,0 +1,341 @@
+/* crc.c - Cyclic redundancy checks.
+ * Copyright (C) 2003 Free Software Foundation, Inc.
+ *
+ * This file is part of Libgcrypt.
+ *
+ * Libgcrypt is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * Libgcrypt is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ *
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include "g10lib.h"
+#include "memory.h"
+#include "dynload.h"
+
+#include "bithelp.h"
+
+/* Table of CRCs of all 8-bit messages.  Generated by running code
+   from RFC 1952 modified to print out the table. */
+static u32 crc32_table[256] = {
+  0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
+  0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
+  0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
+  0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
+  0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
+  0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
+  0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
+  0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
+  0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
+  0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+  0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
+  0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
+  0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
+  0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
+  0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
+  0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
+  0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
+  0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
+  0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
+  0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+  0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
+  0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
+  0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
+  0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
+  0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
+  0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
+  0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
+  0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
+  0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
+  0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+  0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
+  0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
+  0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
+  0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
+  0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
+  0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+  0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
+  0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
+  0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
+  0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+  0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
+  0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
+  0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
+};
+
+/*
+ * The following function was extracted from RFC 1952 by Simon
+ * Josefsson, for the Shishi project, and modified to be compatible
+ * with the modified CRC-32 used by RFC 1510, and subsequently
+ * modified for GNU Libgcrypt to allow it to be used for calculating
+ * both unmodified CRC-32 and modified CRC-32 values.  Original
+ * copyright and notice from the document follows:
+ *
+ *    Copyright (c) 1996 L. Peter Deutsch
+ *
+ *    Permission is granted to copy and distribute this document for
+ *    any purpose and without charge, including translations into
+ *    other languages and incorporation into compilations, provided
+ *    that the copyright notice and this notice are preserved, and
+ *    that any substantive changes or deletions from the original are
+ *    clearly marked.
+ *
+ * The copyright on RFCs, and consequently the function below, are
+ * supposedly also retroactively claimed by the Internet Society
+ * (according to rfc-editor@rfc-editor.org), with the following
+ * copyright notice:
+ *
+ *    Copyright (C) The Internet Society.  All Rights Reserved.
+ *
+ *    This document and translations of it may be copied and furnished
+ *    to others, and derivative works that comment on or otherwise
+ *    explain it or assist in its implementation may be prepared,
+ *    copied, published and distributed, in whole or in part, without
+ *    restriction of any kind, provided that the above copyright
+ *    notice and this paragraph are included on all such copies and
+ *    derivative works.  However, this document itself may not be
+ *    modified in any way, such as by removing the copyright notice or
+ *    references to the Internet Society or other Internet
+ *    organizations, except as needed for the purpose of developing
+ *    Internet standards in which case the procedures for copyrights
+ *    defined in the Internet Standards process must be followed, or
+ *    as required to translate it into languages other than English.
+ *
+ *    The limited permissions granted above are perpetual and will not be
+ *    revoked by the Internet Society or its successors or assigns.
+ *
+ *    This document and the information contained herein is provided
+ *    on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET
+ *    ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR
+ *    IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE
+ *    OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY
+ *    IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
+ *    PARTICULAR PURPOSE.
+ *
+ */
+static u32
+update_crc32 (u32 crc, char *buf, size_t len)
+{
+  size_t n;
+
+  for (n = 0; n < len; n++)
+    crc = crc32_table[(crc ^ buf[n]) & 0xff] ^ (crc >> 8);
+
+  return crc;
+}
+
+typedef struct
+{
+  u32 CRC;
+  byte buf[4];
+}
+CRC_CONTEXT;
+
+/* CRC32 */
+
+static void
+crc32_init (CRC_CONTEXT * ctx)
+{
+  ctx->CRC = 0 ^ 0xffffffffL;
+}
+
+static void
+crc32_write (CRC_CONTEXT * ctx, byte * inbuf, size_t inlen)
+{
+  if (!inbuf)
+    return;
+  ctx->CRC = update_crc32 (ctx->CRC, inbuf, inlen);
+}
+
+static byte *
+crc32_read (CRC_CONTEXT * ctx)
+{
+  return ctx->buf;
+}
+
+static void
+crc32_final (CRC_CONTEXT * ctx)
+{
+  ctx->CRC ^= 0xffffffffL;
+  ctx->buf[0] = (ctx->CRC >> 24) & 0xFF;
+  ctx->buf[1] = (ctx->CRC >> 16) & 0xFF;
+  ctx->buf[2] = (ctx->CRC >>  8) & 0xFF;
+  ctx->buf[3] = (ctx->CRC      ) & 0xFF;
+}
+
+/* CRC32 a'la RFC 1510 */
+
+static void
+crc32rfc1510_init (CRC_CONTEXT * ctx)
+{
+  ctx->CRC = 0;
+}
+
+static void
+crc32rfc1510_final (CRC_CONTEXT * ctx)
+{
+  ctx->buf[0] = (ctx->CRC >> 24) & 0xFF;
+  ctx->buf[1] = (ctx->CRC >> 16) & 0xFF;
+  ctx->buf[2] = (ctx->CRC >>  8) & 0xFF;
+  ctx->buf[3] = (ctx->CRC      ) & 0xFF;
+}
+
+/* CRC24 a'la RFC 2440 */
+
+#define CRC24_INIT 0xb704ceL
+#define CRC24_POLY 0x1864cfbL
+
+static void
+crc24rfc2440_init (CRC_CONTEXT * ctx)
+{
+  ctx->CRC = CRC24_INIT;
+}
+
+static void
+crc24rfc2440_write (CRC_CONTEXT * ctx, byte * inbuf, size_t inlen)
+{
+  int i;
+
+  if (!inbuf)
+    return;
+
+  while (inlen--) {
+    ctx->CRC ^= (*inbuf++) << 16;
+    for (i = 0; i < 8; i++) {
+      ctx->CRC <<= 1;
+      if (ctx->CRC & 0x1000000)
+	ctx->CRC ^= CRC24_POLY;
+    }
+  }
+}
+
+static void
+crc24rfc2440_final (CRC_CONTEXT * ctx)
+{
+  ctx->buf[0] = (ctx->CRC >> 16) & 0xFF;
+  ctx->buf[1] = (ctx->CRC >>  8) & 0xFF;
+  ctx->buf[2] = (ctx->CRC      ) & 0xFF;
+}
+
+static const char *
+crc_get_info (int algo, size_t * contextsize,
+	      byte ** r_asnoid, int *r_asnlen, int *r_mdlen,
+	      void (**r_init) (void *c),
+	      void (**r_write) (void *c, byte * buf, size_t nbytes),
+	      void (**r_final) (void *c), byte * (**r_read) (void *c))
+{
+  *contextsize = sizeof (CRC_CONTEXT);
+  *r_asnoid = NULL;
+  *r_asnlen = 0;
+
+  switch (algo)
+    {
+    case 302:
+      *r_mdlen = 4;
+      *(void (**)(CRC_CONTEXT *)) r_init = crc32_init;
+      *(void (**)(CRC_CONTEXT *)) r_final = crc32_final;
+      *(void (**)(CRC_CONTEXT *, byte *, size_t)) r_write = crc32_write;
+      *(byte * (**)(CRC_CONTEXT *)) r_read = crc32_read;
+      return "CRC32";
+
+    case 303:
+      *r_mdlen = 4;
+      *(void (**)(CRC_CONTEXT *)) r_init = crc32rfc1510_init;
+      *(void (**)(CRC_CONTEXT *)) r_final = crc32rfc1510_final;
+      *(void (**)(CRC_CONTEXT *, byte *, size_t)) r_write = crc32_write;
+      *(byte * (**)(CRC_CONTEXT *)) r_read = crc32_read;
+      return "CRC32RFC1510";
+
+    case 304:
+      *r_mdlen = 3;
+      *(void (**)(CRC_CONTEXT *)) r_init = crc24rfc2440_init;
+      *(void (**)(CRC_CONTEXT *)) r_final = crc24rfc2440_final;
+      *(void (**)(CRC_CONTEXT *, byte *, size_t)) r_write = crc24rfc2440_write;
+      *(byte * (**)(CRC_CONTEXT *)) r_read = crc32_read;
+      return "CRC24RFC2440";
+
+    default:
+      return NULL;
+    }
+
+  return NULL;
+}
+
+
+#ifndef IS_MODULE
+static
+#endif
+const char *const gnupgext_version = "CRC ($Revision$)";
+
+static struct
+{
+  int class;
+  int version;
+  int value;
+  void (*func) (void);
+} func_table[] = {
+  { 10, 1, 0, (void (*)(void)) crc_get_info },
+  { 11, 1, 302 },
+  { 11, 1, 303 },
+  { 11, 1, 304 },
+};
+
+#ifndef IS_MODULE
+static
+#endif
+void *
+gnupgext_enum_func (int what, int *sequence, int *class, int *vers)
+{
+  void *ret;
+  int i = *sequence;
+
+  do
+    {
+      if (i >= DIM (func_table) || i < 0)
+	return NULL;
+      *class = func_table[i].class;
+      *vers = func_table[i].version;
+      switch (*class)
+	{
+	case 11:
+	case 21:
+	case 31:
+	  ret = &func_table[i].value;
+	  break;
+	default:
+	  ret = func_table[i].func;
+	  break;
+	}
+      i++;
+    }
+  while (what && what != *class);
+
+  *sequence = i;
+  return ret;
+}
+
+#ifndef IS_MODULE
+void
+_gcry_crc_constructor (void)
+{
+  _gcry_register_internal_cipher_extension (gnupgext_version,
+					    gnupgext_enum_func);
+}
+#endif
+
+/* end of file */
Index: cipher/md.c
===================================================================
RCS file: /cvs/gnupg/libgcrypt/cipher/md.c,v
retrieving revision 1.60
diff -u -p -r1.60 md.c
--- cipher/md.c	20 Jan 2003 16:58:10 -0000	1.60
+++ cipher/md.c	20 Jan 2003 19:29:02 -0000
@@ -832,6 +832,9 @@ gcry_md_get_algo_dlen( int algo )
     case GCRY_MD_SHA256: return 32;
     case GCRY_MD_SHA384: return 48;
     case GCRY_MD_SHA512: return 64;
+    case GCRY_MD_CRC32:
+    case GCRY_MD_CRC32_RFC1510: return 4;
+    case GCRY_MD_CRC24_RFC2440: return 3;
     default: 
       {
         int len = md_digest_length( algo );
Index: doc/ChangeLog
===================================================================
RCS file: /cvs/gnupg/libgcrypt/doc/ChangeLog,v
retrieving revision 1.7
diff -u -p -r1.7 ChangeLog
--- doc/ChangeLog	19 Jan 2003 20:37:33 -0000	1.7
+++ doc/ChangeLog	20 Jan 2003 19:29:02 -0000
@@ -1,3 +1,7 @@
+2003-01-20  Simon Josefsson  <jas@extundo.com>
+
+	* gcrypt.texi (Hash Functions): Add CRC.
+
 2003-01-19  Werner Koch  <wk@gnupg.org>
 
 	* gcrypt.texi: Most functions are now documented.  Still need to
Index: doc/gcrypt.texi
===================================================================
RCS file: /cvs/gnupg/libgcrypt/doc/gcrypt.texi,v
retrieving revision 1.6
diff -u -p -r1.6 gcrypt.texi
--- doc/gcrypt.texi	20 Jan 2003 16:58:14 -0000	1.6
+++ doc/gcrypt.texi	20 Jan 2003 19:29:02 -0000
@@ -599,7 +599,8 @@ consistent to use interface to hash func
 several hash algorithms can be updated at once.  It is possible to
 calculate a MAC using the same routines.
 
-For convenience reasons, we plan to integrate simple CRC algorithms too
+For convenience reasons, a few cyclic redudance check value operations
+are also supported.
 
 To use most of these function it is necessary to create a context;  this
 is done using:
@@ -655,6 +656,18 @@ This is reserved for SHA-2 with 384 bits
 @item GCRY_MD_SHA512
 This is reserved for SHA-2 with 512 bits. It yields a message digest of
 64 bytes.  Note that there is no implementation yet available.
+
+@item GCRY_MD_CRC32
+This is the ISO 3309 and ITU-T V.42 cyclic redundancy check.  It
+yields an output of 4 bytes.
+
+@item GCRY_MD_CRC32_RFC1510
+This is the above cyclic redundancy check function, as modified by RFC
+1510.  It yields an output of 4 bytes.
+
+@item GCRY_MD_CRC24_RFC2440
+This is the OpenPGP cyclic redundancy check function.  It yields an
+output of 3 bytes.
 
 @end table
 @c end table of hash algorithms
Index: src/ChangeLog
===================================================================
RCS file: /cvs/gnupg/libgcrypt/src/ChangeLog,v
retrieving revision 1.68
diff -u -p -r1.68 ChangeLog
--- src/ChangeLog	20 Jan 2003 10:25:21 -0000	1.68
+++ src/ChangeLog	20 Jan 2003 19:29:03 -0000
@@ -1,3 +1,8 @@
+2003-01-20  Simon Josefsson  <jas@extundo.com>
+
+	* gcrypt.h (gcry_md_algos): Add GCRY_MD_CRC32,
+	GCRY_MD_CRC32_RFC1510, GCRY_MD_CRC24_RFC2440.
+
 2003-01-16  Werner Koch  <wk@gnupg.org>
 
 	* gcrypt.h (gcry_md_write): Changed type of 2nd argument to void*.
Index: src/gcrypt.h
===================================================================
RCS file: /cvs/gnupg/libgcrypt/src/gcrypt.h,v
retrieving revision 1.69
diff -u -p -r1.69 gcrypt.h
--- src/gcrypt.h	20 Jan 2003 16:58:17 -0000	1.69
+++ src/gcrypt.h	20 Jan 2003 19:29:03 -0000
@@ -698,7 +698,10 @@ enum gcry_md_algos
     GCRY_MD_SHA256  = 8,
     GCRY_MD_SHA384  = 9,
     GCRY_MD_SHA512  = 10,
-    GCRY_MD_MD4     = 301
+    GCRY_MD_MD4     = 301,
+    GCRY_MD_CRC32		= 302,
+    GCRY_MD_CRC32_RFC1510	= 303,
+    GCRY_MD_CRC24_RFC2440	= 304
   };
 
 /* Flags used with the open function. */
Index: tests/ChangeLog
===================================================================
RCS file: /cvs/gnupg/libgcrypt/tests/ChangeLog,v
retrieving revision 1.12
diff -u -p -r1.12 ChangeLog
--- tests/ChangeLog	20 Jan 2003 16:58:20 -0000	1.12
+++ tests/ChangeLog	20 Jan 2003 19:29:03 -0000
@@ -1,3 +1,8 @@
+2003-01-20  Simon Josefsson  <jas@extundo.com>
+
+	* basic.c (check_digests): Add CRC.
+	(check_one_md): Print computed and expected values on error.
+
 2003-01-20  Werner Koch  <wk@gnupg.org>
 
 	* basic.c (check_one_md): Kludge to check a one million "a".
Index: tests/basic.c
===================================================================
RCS file: /cvs/gnupg/libgcrypt/tests/basic.c,v
retrieving revision 1.9
diff -u -p -r1.9 basic.c
--- tests/basic.c	20 Jan 2003 16:58:20 -0000	1.9
+++ tests/basic.c	20 Jan 2003 19:29:03 -0000
@@ -319,7 +319,17 @@ check_one_md (int algo, char *data, int 
     p = gcry_md_read (hd, algo);
 
     if ( memcmp (p, expect, mdlen) )
-        fail ("algo %d, digest mismatch\n", algo);
+      {
+	printf("computed: ");
+	for (i=0; i < mdlen; i++)
+	  printf("%02x ", p[i] & 0xFF);
+	printf("\nexpected: ");
+	for (i=0; i < mdlen; i++)
+	  printf("%02x ", expect[i] & 0xFF);
+	printf("\n");
+
+	fail ("algo %d, digest mismatch\n", algo);
+      }
 
     gcry_md_close (hd);
 }
@@ -376,6 +386,38 @@ check_digests ()
     { GCRY_MD_RMD160, "message digest",
       "\x5d\x06\x89\xef\x49\xd2\xfa\xe5\x72\xb8"
       "\x81\xb1\x23\xa8\x5f\xfa\x21\x59\x5f\x36" },
+    { GCRY_MD_CRC32, "",
+      "\x00\x00\x00\x00" },
+    { GCRY_MD_CRC32, "foo",
+      "\x8c\x73\x65\x21" },
+    { GCRY_MD_CRC32_RFC1510, "",
+      "\x00\x00\x00\x00" },
+    { GCRY_MD_CRC32_RFC1510, "foo",
+      "\x73\x32\xbc\x33" }, 
+    { GCRY_MD_CRC32_RFC1510, "test0123456789",
+      "\xb8\x3e\x88\xd6" },
+    { GCRY_MD_CRC32_RFC1510, "MASSACHVSETTS INSTITVTE OF TECHNOLOGY",
+      "\xe3\x41\x80\xf7" },
+#if 0
+    { GCRY_MD_CRC32_RFC1510, "\x80\x00",
+      "\x3b\x83\x98\x4b" },
+    { GCRY_MD_CRC32_RFC1510, "\x00\x08",
+      "\x0e\xdb\x88\x32" },
+    { GCRY_MD_CRC32_RFC1510, "\x00\x80",
+      "\xed\xb8\x83\x20" },
+#endif
+    { GCRY_MD_CRC32_RFC1510, "\x80",
+      "\xed\xb8\x83\x20" },
+#if 0
+    { GCRY_MD_CRC32_RFC1510, "\x80\x00\x00\x00",
+      "\xed\x59\xb6\x3b" },
+    { GCRY_MD_CRC32_RFC1510, "\x00\x00\x00\x01",
+      "\x77\x07\x30\x96" },
+#endif
+    { GCRY_MD_CRC24_RFC2440, "",
+      "\xb7\x04\xce" },
+    { GCRY_MD_CRC24_RFC2440, "foo",
+      "\x4f\xc2\x55" },
 #if 0
     { GCRY_MD_TIGER, "",
       "\x24\xF0\x13\x0C\x63\xAC\x93\x32\x16\x16\x6E\x76"