print-esp.c - platform/external/tcpdump - Git at Google

 /*	$NetBSD: print-ah.c,v 1.4 1996/05/20 00:41:16 fvdl Exp $	*/

 /*
  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994
  *	The Regents of the University of California.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that: (1) source code distributions
  * retain the above copyright notice and this paragraph in its entirety, (2)
  * distributions including binary code include the above copyright notice and
  * this paragraph in its entirety in the documentation or other materials
  * provided with the distribution, and (3) all advertising materials mentioning
  * features or use of this software display the following acknowledgement:
  * ``This product includes software developed by the University of California,
  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  * the University nor the names of its contributors may be used to endorse
  * or promote products derived from this software without specific prior
  * written permission.
  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */

 #ifndef lint
 static const char rcsid[] =
     "@(#) $Header: /tcpdump/master/tcpdump/print-esp.c,v 1.39 2003-05-02 08:43:28 guy Exp $ (LBL)";
 #endif

 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif

 #include <string.h>

 #include <tcpdump-stdinc.h>

 #include <stdlib.h>

 #ifdef HAVE_LIBCRYPTO
 #include <openssl/des.h>
 #include <openssl/blowfish.h>
 #ifdef HAVE_OPENSSL_RC5_H
 #include <openssl/rc5.h>
 #endif
 #ifdef HAVE_OPENSSL_CAST_H
 #include <openssl/cast.h>
 #endif
 #endif

 #include <stdio.h>

 #include "ip.h"
 #include "esp.h"
 #ifdef INET6
 #include "ip6.h"
 #endif

 #if defined(__MINGW32__) || defined(__WATCOMC__)
 extern char *strsep (char **stringp, const char *delim); /* Missing/strsep.c */
 #endif

 #define AVOID_CHURN 1
 #include "interface.h"
 #include "addrtoname.h"
 #include "extract.h"

 enum cipher { NONE,
 	      DESCBC,
 	      BLOWFISH,
 	      RC5,
 	      CAST128,
 	      DES3CBC};


 struct esp_algorithm {
   const char   *name;
   enum  cipher algo;
   int          ivlen;
   int          authlen;
   int          replaysize;   /* number of bytes, in excess of 4,
 				may be negative */
 };

 struct esp_algorithm esp_xforms[]={
 	{"none",                  NONE,    0,  0, 0},
 	{"des-cbc",               DESCBC,  8,  0, 0},
 	{"des-cbc-hmac96",        DESCBC,  8, 12, 0},
 	{"blowfish-cbc",          BLOWFISH,8,  0, 0},
 	{"blowfish-cbc-hmac96",   BLOWFISH,8, 12, 0},
 	{"rc5-cbc",               RC5,     8,  0, 0},
 	{"rc5-cbc-hmac96",        RC5,     8, 12, 0},
 	{"cast128-cbc",           CAST128, 8,  0, 0},
 	{"cast128-cbc-hmac96",    CAST128, 8, 12, 0},
 	{"3des-cbc-hmac96",       DES3CBC, 8, 12, 0},
 	{NULL,                    NONE,    0,  0, 0}
 };

 struct esp_algorithm *null_xf =
   &esp_xforms[sizeof(esp_xforms)/sizeof(esp_xforms[0]) - 1];

 #ifndef HAVE_SOCKADDR_STORAGE
 #ifdef INET6
 struct sockaddr_storage {
 	union {
 		struct sockaddr_in sin;
 		struct sockaddr_in6 sin6;
 	} un;
 };
 #else
 #define sockaddr_storage sockaddr
 #endif
 #endif /* HAVE_SOCKADDR_STORAGE */

 struct sa_list {
   struct sa_list *next;
   struct sockaddr_storage daddr;
   u_int32_t      spi;
   struct         esp_algorithm *xform;
   char           secret[256];  /* is that big enough for all secrets? */
   int            secretlen;
 };

 static struct sa_list *sa_list_head=NULL;
 static struct sa_list *sa_default=NULL;

 static void esp_print_addsa(struct sa_list *sa, int sa_def)
 {
   /* copy the "sa" */

   struct sa_list *nsa;

   nsa = (struct sa_list *)malloc(sizeof(struct sa_list));
   if (nsa == NULL)
     error("ran out of memory to allocate sa structure");

   *nsa = *sa;

   if(sa_def) {
     sa_default = nsa;
   }

   nsa->next = sa_list_head;
   sa_list_head = nsa;
 }


 static int hexdigit(char hex)
 {
 	if(hex >= '0' && hex <= '9') {
 		return (hex - '0');
 	} else if(hex >= 'A' && hex <= 'F') {
 		return (hex - 'A' + 10);
 	} else if(hex >= 'a' && hex <= 'f') {
 		return (hex - 'a' + 10);
 	} else {
 		printf("invalid hex digit %c in espsecret\n", hex);
 		return 0;
 	}
 }

 static int hex2byte(char *hexstring)
 {
 	int byte;

 	byte = (hexdigit(hexstring[0]) << 4) +
 		hexdigit(hexstring[1]);
 	return byte;
 }

 /*
  * decode the form:    SPINUM@IP <tab> ALGONAME:0xsecret
  *
  * special form: file /name
  * causes us to go read from this file instead.
  *
  */

 static void esp_print_decode_onesecret(char *line)
 {
   struct esp_algorithm *xf;
   struct sa_list sa1;
   int sa_def;

   char *spikey;
   char *decode;

   spikey = strsep(&line, " \t");
   sa_def = 0;
   memset(&sa1, 0, sizeof(struct sa_list));

   /* if there is only one token, then it is an algo:key token */
   if(line == NULL) {
     decode = spikey;
     spikey = NULL;
     /* memset(&sa1.daddr, 0, sizeof(sa1.daddr)); */
     /* sa1.spi = 0; */
     sa_def    = 1;
   } else {
     decode = line;
   }

   if(spikey && strcasecmp(spikey, "file")==0) {
     /* open file and read it */
     FILE *secretfile;
     char  fileline[1024];
     char  *nl;

     secretfile = fopen(line, FOPEN_READ_TXT);
     if(secretfile == NULL) {
       perror(line);
       exit(3);
     }

     while(fgets(fileline, sizeof(fileline)-1, secretfile) != NULL) {

       /* remove newline from the line */
       nl = strchr(fileline, '\n');
       if(nl) {
 	*nl = '\0';
       }
       if(fileline[0]=='#') continue;
       if(fileline[0]=='\0') continue;

       esp_print_decode_onesecret(fileline);
     }
     fclose(secretfile);

     return;
   }

   if(spikey) {
     char *spistr, *foo;
     u_int32_t spino;
     struct sockaddr_in *sin;
 #ifdef INET6
     struct sockaddr_in6 *sin6;
 #endif

     spistr = strsep(&spikey, "@");

     spino = strtoul(spistr, &foo, 0);
     if(spistr == foo || !spikey) {
       printf("print_esp: failed to decode spi# %s\n", foo);
       return;
     }

     sa1.spi = spino;

     sin = (struct sockaddr_in *)&sa1.daddr;
 #ifdef INET6
     sin6 = (struct sockaddr_in6 *)&sa1.daddr;
     if(inet_pton(AF_INET6, spikey, &sin6->sin6_addr) == 1) {
 #ifdef HAVE_SOCKADDR_SA_LEN
       sin6->sin6_len = sizeof(struct sockaddr_in6);
 #endif
       sin6->sin6_family = AF_INET6;
     } else
 #endif
     if(inet_pton(AF_INET, spikey, &sin->sin_addr) == 1) {
 #ifdef HAVE_SOCKADDR_SA_LEN
       sin->sin_len = sizeof(struct sockaddr_in);
 #endif
       sin->sin_family = AF_INET;
     } else {
       printf("print_esp: can not decode IP# %s\n", spikey);
       return;
     }
   }

   if(decode) {
     char *colon;
     char  espsecret_key[256];
     unsigned int   len, i;

     /* skip any blank spaces */
     while(isspace((unsigned char)*decode)) decode++;

     colon = strchr(decode, ':');
     if(colon == NULL) {
       printf("failed to decode espsecret: %s\n", decode);
       return;
     }

     len = colon - decode;
     xf = esp_xforms;
     while(xf->name && strncasecmp(decode, xf->name, len)!=0) {
       xf++;
     }
     if(xf->name == NULL) {
       printf("failed to find cipher algo %s\n", decode);
       /* set to NULL transform */
       return;
     }
     sa1.xform = xf;

     colon++;
     if(colon[0]=='0' && colon[1]=='x') {
       /* decode some hex! */
       colon+=2;
       len = strlen(colon) / 2;

       if(len > 256) {
 	printf("secret is too big: %d\n", len);
 	return;
       }

       i = 0;
       while(colon[0] != '\0' && colon[1]!='\0') {
 	espsecret_key[i]=hex2byte(colon);
 	colon+=2;
 	i++;
       }
       memcpy(sa1.secret, espsecret_key, i);
       sa1.secretlen=i;
     } else {
       i = strlen(colon);
       if(i < sizeof(sa1.secret)) {
 	memcpy(sa1.secret, espsecret_key, i);
 	sa1.secretlen = i;
       } else {
 	memcpy(sa1.secret, espsecret_key, sizeof(sa1.secret));
 	sa1.secretlen = sizeof(sa1.secret);
       }
     }

   }

   esp_print_addsa(&sa1, sa_def);
 }


 static void esp_print_decodesecret(void)
 {
   char *line;
   char *p;

   if(espsecret == NULL) {
     sa_list_head = NULL;
     return;
   }

   if(sa_list_head != NULL) {
     return;
   }

   p=espsecret;

   while(espsecret && espsecret[0]!='\0') {
     /* pick out the first line or first thing until a comma */
     if((line = strsep(&espsecret, "\n,"))==NULL) {
       line=espsecret;
       espsecret=NULL;
     }

     esp_print_decode_onesecret(line);
   }
 }

 int
 esp_print(register const u_char *bp, register const u_char *bp2,
 	  int *nhdr, int *padlen)
 {
 	register const struct newesp *esp;
 	register const u_char *ep;
 	struct ip *ip;
 	struct sa_list *sa = NULL;
 	int espsecret_keylen;
 #ifdef INET6
 	struct ip6_hdr *ip6 = NULL;
 #endif
 	int advance;
 	int len;
 	char *secret;
 	int ivlen = 0;
 	u_char *ivoff;
 #ifdef HAVE_LIBCRYPTO
 	u_char *p;
 #endif

 	esp = (struct newesp *)bp;
 	secret = NULL;
 	advance = 0;

 #if 0
 	/* keep secret out of a register */
 	p = (u_char *)&secret;
 #endif

 	/* 'ep' points to the end of available data. */
 	ep = snapend;

 	if ((u_char *)(esp + 1) >= ep) {
 		fputs("[|ESP]", stdout);
 		goto fail;
 	}
 	printf("ESP(spi=0x%08x", EXTRACT_32BITS(&esp->esp_spi));
 	printf(",seq=0x%x", EXTRACT_32BITS(&esp->esp_seq));
 	printf(")");

 	/* if we don't have decryption key, we can't decrypt this packet. */
 	if(sa_list_head == NULL) {
 	  if (!espsecret) {
 	    goto fail;
 	  }
 	  esp_print_decodesecret();
 	}

 	if(sa_list_head == NULL) {
 		goto fail;
 	}

 	ip = (struct ip *)bp2;
 	switch (IP_V(ip)) {
 #ifdef INET6
 	case 6:
 		ip6 = (struct ip6_hdr *)bp2;
 		/* we do not attempt to decrypt jumbograms */
 		if (!EXTRACT_16BITS(&ip6->ip6_plen))
 			goto fail;
 		/* if we can't get nexthdr, we do not need to decrypt it */
 		len = sizeof(struct ip6_hdr) + EXTRACT_16BITS(&ip6->ip6_plen);

 		/* see if we can find the SA, and if so, decode it */
 		for (sa = sa_list_head; sa != NULL; sa = sa->next) {
 			struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&sa->daddr;
 			if (sa->spi == ntohl(esp->esp_spi) &&
 			    sin6->sin6_family == AF_INET6 &&
 			    memcmp(&sin6->sin6_addr, &ip6->ip6_dst,
 				   sizeof(struct in6_addr)) == 0) {
 				break;
 			}
 		}
 		break;
 #endif /*INET6*/
 	case 4:
 		/* nexthdr & padding are in the last fragment */
 		if (EXTRACT_16BITS(&ip->ip_off) & IP_MF)
 			goto fail;
 		len = EXTRACT_16BITS(&ip->ip_len);

 		/* see if we can find the SA, and if so, decode it */
 		for (sa = sa_list_head; sa != NULL; sa = sa->next) {
 			struct sockaddr_in *sin = (struct sockaddr_in *)&sa->daddr;
 			if (sa->spi == ntohl(esp->esp_spi) &&
 			    sin->sin_family == AF_INET &&
 			    sin->sin_addr.s_addr == ip->ip_dst.s_addr) {
 				break;
 			}
 		}
 		break;
 	default:
 		goto fail;
 	}

 	/* if we didn't find the specific one, then look for
 	 * an unspecified one.
 	 */
 	if(sa == NULL) {
 		sa = sa_default;
 	}

 	/* if not found fail */
 	if(sa == NULL)
 		goto fail;

 	/* if we can't get nexthdr, we do not need to decrypt it */
 	if (ep - bp2 < len)
 		goto fail;
 	if (ep - bp2 > len) {
 		/* FCS included at end of frame (NetBSD 1.6 or later) */
 		ep = bp2 + len;
 	}

 	ivoff = (u_char *)(esp + 1) + sa->xform->replaysize;
 	ivlen = sa->xform->ivlen;
 	secret = sa->secret;
 	espsecret_keylen = sa->secretlen;

 	switch (sa->xform->algo) {
 	case DESCBC:
 #ifdef HAVE_LIBCRYPTO
 	    {
 		u_char iv[8];
 #if OPENSSL_VERSION_NUMBER >= 0x00907000L
 		DES_key_schedule schedule;
 #else
 		des_key_schedule schedule;
 #endif

 		switch (ivlen) {
 		case 4:
 			memcpy(iv, ivoff, 4);
 			memcpy(&iv[4], ivoff, 4);
 			p = &iv[4];
 			*p++ ^= 0xff;
 			*p++ ^= 0xff;
 			*p++ ^= 0xff;
 			*p++ ^= 0xff;
 			break;
 		case 8:
 			memcpy(iv, ivoff, 8);
 			break;
 		default:
 			goto fail;
 		}
 		p = ivoff + ivlen;

 		if (espsecret_keylen != 8)
 			goto fail;

 #if OPENSSL_VERSION_NUMBER >= 0x00908000L
 		DES_set_key_unchecked((const_DES_cblock *)secret, &schedule);

 		DES_cbc_encrypt((const unsigned char *)p, p,
 			(long)(ep - p), &schedule, (DES_cblock *)iv,
 			DES_DECRYPT);

 #elif OPENSSL_VERSION_NUMBER >= 0x00907000L
 		DES_set_key_unchecked((DES_cblock *)secret, schedule);

 		DES_cbc_encrypt((const unsigned char *)p, p,
 			(long)(ep - p), schedule, (DES_cblock *)iv,
 			DES_DECRYPT);
 #else
 		des_check_key = 0;
 		des_set_key((void *)secret, schedule);

 		des_cbc_encrypt((void *)p, (void *)p,
 			(long)(ep - p), schedule, (void *)iv,
 			DES_DECRYPT);
 #endif
 		advance = ivoff - (u_char *)esp + ivlen;
 		break;
 	    }
 #else
 		goto fail;
 #endif /*HAVE_LIBCRYPTO*/

 	case BLOWFISH:
 #ifdef HAVE_LIBCRYPTO
 	    {
 		BF_KEY schedule;

 		if (espsecret_keylen < 5 || espsecret_keylen > 56)
 			goto fail;
 		BF_set_key(&schedule, espsecret_keylen, secret);

 		p = ivoff + ivlen;
 		BF_cbc_encrypt(p, p, (long)(ep - p), &schedule, ivoff,
 			BF_DECRYPT);
 		advance = ivoff - (u_char *)esp + ivlen;
 		break;
 	    }
 #else
 		goto fail;
 #endif /*HAVE_LIBCRYPTO*/

 	case RC5:
 #if defined(HAVE_LIBCRYPTO) && defined(HAVE_RC5_H)
 	    {
 		RC5_32_KEY schedule;

 		if (espsecret_keylen < 5 || espsecret_keylen > 255)
 			goto fail;
 		RC5_32_set_key(&schedule, espsecret_keylen, secret,
 			RC5_16_ROUNDS);

 		p = ivoff + ivlen;
 		RC5_32_cbc_encrypt(p, p, (long)(ep - p), &schedule, ivoff,
 			RC5_DECRYPT);
 		advance = ivoff - (u_char *)esp + ivlen;
 		break;
 	    }
 #else
 		goto fail;
 #endif /*HAVE_LIBCRYPTO*/

 	case CAST128:
 #if defined(HAVE_LIBCRYPTO) && defined(HAVE_CAST_H) && !defined(HAVE_BUGGY_CAST128)
 	    {
 		CAST_KEY schedule;

 		if (espsecret_keylen < 5 || espsecret_keylen > 16)
 			goto fail;
 		CAST_set_key(&schedule, espsecret_keylen, secret);

 		p = ivoff + ivlen;
 		CAST_cbc_encrypt(p, p, (long)(ep - p), &schedule, ivoff,
 			CAST_DECRYPT);
 		advance = ivoff - (u_char *)esp + ivlen;
 		break;
 	    }
 #else
 		goto fail;
 #endif /*HAVE_LIBCRYPTO*/

 	case DES3CBC:
 #if defined(HAVE_LIBCRYPTO)
 	    {
 #if OPENSSL_VERSION_NUMBER >= 0x00907000L
 		DES_key_schedule s1, s2, s3;

 		if (espsecret_keylen != 24)
 			goto fail;
 		DES_set_odd_parity((DES_cblock *)secret);
 		DES_set_odd_parity((DES_cblock *)(secret + 8));
 		DES_set_odd_parity((DES_cblock *)(secret + 16));
 #if OPENSSL_VERSION_NUMBER >= 0x00908000L
 		if(DES_set_key_checked((const_DES_cblock *)secret, &s1) != 0) {
 		  printf("failed to schedule key 1\n");
 		}
 		if(DES_set_key_checked((const_DES_cblock *)(secret + 8), &s2)!=0) {
 		  printf("failed to schedule key 2\n");
 		}
 		if(DES_set_key_checked((const_DES_cblock *)(secret + 16), &s3)!=0) {
 		  printf("failed to schedule key 3\n");
 		}
 #else
 		if(DES_set_key_checked((DES_cblock *)secret, s1) != 0) {
 		  printf("failed to schedule key 1\n");
 		}
 		if(DES_set_key_checked((DES_cblock *)(secret + 8), s2)!=0) {
 		  printf("failed to schedule key 2\n");
 		}
 		if(DES_set_key_checked((DES_cblock *)(secret + 16), s3)!=0) {
 		  printf("failed to schedule key 3\n");
 		}
 #endif

 		p = ivoff + ivlen;
 		DES_ede3_cbc_encrypt((const unsigned char *)p, p,
 				     (long)(ep - p),
 				     &s1, &s2, &s3,
 				     (DES_cblock *)ivoff, DES_DECRYPT);
 #else
 		des_key_schedule s1, s2, s3;

 		if (espsecret_keylen != 24)
 			goto fail;
 		des_check_key = 1;
 		des_set_odd_parity((void *)secret);
 		des_set_odd_parity((void *)(secret + 8));
 		des_set_odd_parity((void *)(secret + 16));
 		if(des_set_key((void *)secret, s1) != 0) {
 		  printf("failed to schedule key 1\n");
 		}
 		if(des_set_key((void *)(secret + 8), s2)!=0) {
 		  printf("failed to schedule key 2\n");
 		}
 		if(des_set_key((void *)(secret + 16), s3)!=0) {
 		  printf("failed to schedule key 3\n");
 		}

 		p = ivoff + ivlen;
 		des_ede3_cbc_encrypt((void *)p, (void *)p,
 				     (long)(ep - p),
 				     s1, s2, s3,
 				     (void *)ivoff, DES_DECRYPT);
 #endif
 		advance = ivoff - (u_char *)esp + ivlen;
 		break;
 	    }
 #else
 		goto fail;
 #endif /*HAVE_LIBCRYPTO*/

 	case NONE:
 	default:
 		advance = sizeof(struct newesp) + sa->xform->replaysize;
 		break;
 	}

 	ep = ep - sa->xform->authlen;
 	/* sanity check for pad length */
 	if (ep - bp < *(ep - 2))
 		goto fail;

 	if (padlen)
 		*padlen = *(ep - 2) + 2;

 	if (nhdr)
 		*nhdr = *(ep - 1);

 	printf(": ");
 	return advance;

 fail:
 	if (nhdr)
 		*nhdr = -1;
 	return 65536;
 }
	/* $NetBSD: print-ah.c,v 1.4 1996/05/20 00:41:16 fvdl Exp $ */

	/*
	* Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994
	* The Regents of the University of California. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that: (1) source code distributions
	* retain the above copyright notice and this paragraph in its entirety, (2)
	* distributions including binary code include the above copyright notice and
	* this paragraph in its entirety in the documentation or other materials
	* provided with the distribution, and (3) all advertising materials mentioning
	* features or use of this software display the following acknowledgement:
	* ``This product includes software developed by the University of California,
	* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
	* the University nor the names of its contributors may be used to endorse
	* or promote products derived from this software without specific prior
	* written permission.
	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
	* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
	*/

	#ifndef lint
	static const char rcsid[] =
	"@(#) $Header: /tcpdump/master/tcpdump/print-esp.c,v 1.39 2003-05-02 08:43:28 guy Exp $ (LBL)";
	#endif

	#ifdef HAVE_CONFIG_H
	#include "config.h"
	#endif

	#include <string.h>

	#include <tcpdump-stdinc.h>

	#include <stdlib.h>

	#ifdef HAVE_LIBCRYPTO
	#include <openssl/des.h>
	#include <openssl/blowfish.h>
	#ifdef HAVE_OPENSSL_RC5_H
	#include <openssl/rc5.h>
	#endif
	#ifdef HAVE_OPENSSL_CAST_H
	#include <openssl/cast.h>
	#endif
	#endif

	#include <stdio.h>

	#include "ip.h"
	#include "esp.h"
	#ifdef INET6
	#include "ip6.h"
	#endif

	#if defined(__MINGW32__) \|\| defined(__WATCOMC__)
	extern char strsep (char stringp, const char delim); /* Missing/strsep.c */
	#endif

	#define AVOID_CHURN 1
	#include "interface.h"
	#include "addrtoname.h"
	#include "extract.h"

	enum cipher { NONE,
	DESCBC,
	BLOWFISH,
	RC5,
	CAST128,
	DES3CBC};



	struct esp_algorithm {
	const char *name;
	enum cipher algo;
	int ivlen;
	int authlen;
	int replaysize; /* number of bytes, in excess of 4,
	may be negative */
	};

	struct esp_algorithm esp_xforms[]={
	{"none", NONE, 0, 0, 0},
	{"des-cbc", DESCBC, 8, 0, 0},
	{"des-cbc-hmac96", DESCBC, 8, 12, 0},
	{"blowfish-cbc", BLOWFISH,8, 0, 0},
	{"blowfish-cbc-hmac96", BLOWFISH,8, 12, 0},
	{"rc5-cbc", RC5, 8, 0, 0},
	{"rc5-cbc-hmac96", RC5, 8, 12, 0},
	{"cast128-cbc", CAST128, 8, 0, 0},
	{"cast128-cbc-hmac96", CAST128, 8, 12, 0},
	{"3des-cbc-hmac96", DES3CBC, 8, 12, 0},
	{NULL, NONE, 0, 0, 0}
	};

	struct esp_algorithm *null_xf =
	&esp_xforms[sizeof(esp_xforms)/sizeof(esp_xforms[0]) - 1];

	#ifndef HAVE_SOCKADDR_STORAGE
	#ifdef INET6
	struct sockaddr_storage {
	union {
	struct sockaddr_in sin;
	struct sockaddr_in6 sin6;
	} un;
	};
	#else
	#define sockaddr_storage sockaddr
	#endif
	#endif /* HAVE_SOCKADDR_STORAGE */

	struct sa_list {
	struct sa_list *next;
	struct sockaddr_storage daddr;
	u_int32_t spi;
	struct esp_algorithm *xform;
	char secret[256]; /* is that big enough for all secrets? */
	int secretlen;
	};

	static struct sa_list *sa_list_head=NULL;
	static struct sa_list *sa_default=NULL;

	static void esp_print_addsa(struct sa_list *sa, int sa_def)
	{
	/* copy the "sa" */

	struct sa_list *nsa;

	nsa = (struct sa_list *)malloc(sizeof(struct sa_list));
	if (nsa == NULL)
	error("ran out of memory to allocate sa structure");

	nsa = sa;

	if(sa_def) {
	sa_default = nsa;
	}

	nsa->next = sa_list_head;
	sa_list_head = nsa;
	}


	static int hexdigit(char hex)
	{
	if(hex >= '0' && hex <= '9') {
	return (hex - '0');
	} else if(hex >= 'A' && hex <= 'F') {
	return (hex - 'A' + 10);
	} else if(hex >= 'a' && hex <= 'f') {
	return (hex - 'a' + 10);
	} else {
	printf("invalid hex digit %c in espsecret\n", hex);
	return 0;
	}
	}

	static int hex2byte(char *hexstring)
	{
	int byte;

	byte = (hexdigit(hexstring[0]) << 4) +
	hexdigit(hexstring[1]);
	return byte;
	}

	/*
	* decode the form: SPINUM@IP <tab> ALGONAME:0xsecret
	*
	* special form: file /name
	* causes us to go read from this file instead.
	*
	*/

	static void esp_print_decode_onesecret(char *line)
	{
	struct esp_algorithm *xf;
	struct sa_list sa1;
	int sa_def;

	char *spikey;
	char *decode;

	spikey = strsep(&line, " \t");
	sa_def = 0;
	memset(&sa1, 0, sizeof(struct sa_list));

	/* if there is only one token, then it is an algo:key token */
	if(line == NULL) {
	decode = spikey;
	spikey = NULL;
	/* memset(&sa1.daddr, 0, sizeof(sa1.daddr)); */
	/* sa1.spi = 0; */
	sa_def = 1;
	} else {
	decode = line;
	}

	if(spikey && strcasecmp(spikey, "file")==0) {
	/* open file and read it */
	FILE *secretfile;
	char fileline[1024];
	char *nl;

	secretfile = fopen(line, FOPEN_READ_TXT);
	if(secretfile == NULL) {
	perror(line);
	exit(3);
	}

	while(fgets(fileline, sizeof(fileline)-1, secretfile) != NULL) {

	/* remove newline from the line */
	nl = strchr(fileline, '\n');
	if(nl) {
	*nl = '\0';
	}
	if(fileline[0]=='#') continue;
	if(fileline[0]=='\0') continue;

	esp_print_decode_onesecret(fileline);
	}
	fclose(secretfile);

	return;
	}

	if(spikey) {
	char spistr, foo;
	u_int32_t spino;
	struct sockaddr_in *sin;
	#ifdef INET6
	struct sockaddr_in6 *sin6;
	#endif

	spistr = strsep(&spikey, "@");

	spino = strtoul(spistr, &foo, 0);
	if(spistr == foo \|\| !spikey) {
	printf("print_esp: failed to decode spi# %s\n", foo);
	return;
	}

	sa1.spi = spino;

	sin = (struct sockaddr_in *)&sa1.daddr;
	#ifdef INET6
	sin6 = (struct sockaddr_in6 *)&sa1.daddr;
	if(inet_pton(AF_INET6, spikey, &sin6->sin6_addr) == 1) {
	#ifdef HAVE_SOCKADDR_SA_LEN
	sin6->sin6_len = sizeof(struct sockaddr_in6);
	#endif
	sin6->sin6_family = AF_INET6;
	} else
	#endif
	if(inet_pton(AF_INET, spikey, &sin->sin_addr) == 1) {
	#ifdef HAVE_SOCKADDR_SA_LEN
	sin->sin_len = sizeof(struct sockaddr_in);
	#endif
	sin->sin_family = AF_INET;
	} else {
	printf("print_esp: can not decode IP# %s\n", spikey);
	return;
	}
	}

	if(decode) {
	char *colon;
	char espsecret_key[256];
	unsigned int len, i;

	/* skip any blank spaces */
	while(isspace((unsigned char)*decode)) decode++;

	colon = strchr(decode, ':');
	if(colon == NULL) {
	printf("failed to decode espsecret: %s\n", decode);
	return;
	}

	len = colon - decode;
	xf = esp_xforms;
	while(xf->name && strncasecmp(decode, xf->name, len)!=0) {
	xf++;
	}
	if(xf->name == NULL) {
	printf("failed to find cipher algo %s\n", decode);
	/* set to NULL transform */
	return;
	}
	sa1.xform = xf;

	colon++;
	if(colon[0]=='0' && colon[1]=='x') {
	/* decode some hex! */
	colon+=2;
	len = strlen(colon) / 2;

	if(len > 256) {
	printf("secret is too big: %d\n", len);
	return;
	}

	i = 0;
	while(colon[0] != '\0' && colon[1]!='\0') {
	espsecret_key[i]=hex2byte(colon);
	colon+=2;
	i++;
	}
	memcpy(sa1.secret, espsecret_key, i);
	sa1.secretlen=i;
	} else {
	i = strlen(colon);
	if(i < sizeof(sa1.secret)) {
	memcpy(sa1.secret, espsecret_key, i);
	sa1.secretlen = i;
	} else {
	memcpy(sa1.secret, espsecret_key, sizeof(sa1.secret));
	sa1.secretlen = sizeof(sa1.secret);
	}
	}

	}

	esp_print_addsa(&sa1, sa_def);
	}


	static void esp_print_decodesecret(void)
	{
	char *line;
	char *p;

	if(espsecret == NULL) {
	sa_list_head = NULL;
	return;
	}

	if(sa_list_head != NULL) {
	return;
	}

	p=espsecret;

	while(espsecret && espsecret[0]!='\0') {
	/* pick out the first line or first thing until a comma */
	if((line = strsep(&espsecret, "\n,"))==NULL) {
	line=espsecret;
	espsecret=NULL;
	}

	esp_print_decode_onesecret(line);
	}
	}

	int
	esp_print(register const u_char bp, register const u_char bp2,
	int nhdr, int padlen)
	{
	register const struct newesp *esp;
	register const u_char *ep;
	struct ip *ip;
	struct sa_list *sa = NULL;
	int espsecret_keylen;
	#ifdef INET6
	struct ip6_hdr *ip6 = NULL;
	#endif
	int advance;
	int len;
	char *secret;
	int ivlen = 0;
	u_char *ivoff;
	#ifdef HAVE_LIBCRYPTO
	u_char *p;
	#endif

	esp = (struct newesp *)bp;
	secret = NULL;
	advance = 0;

	#if 0
	/* keep secret out of a register */
	p = (u_char *)&secret;
	#endif

	/* 'ep' points to the end of available data. */
	ep = snapend;

	if ((u_char *)(esp + 1) >= ep) {
	fputs("[\|ESP]", stdout);
	goto fail;
	}
	printf("ESP(spi=0x%08x", EXTRACT_32BITS(&esp->esp_spi));
	printf(",seq=0x%x", EXTRACT_32BITS(&esp->esp_seq));
	printf(")");

	/* if we don't have decryption key, we can't decrypt this packet. */
	if(sa_list_head == NULL) {
	if (!espsecret) {
	goto fail;
	}
	esp_print_decodesecret();
	}

	if(sa_list_head == NULL) {
	goto fail;
	}

	ip = (struct ip *)bp2;
	switch (IP_V(ip)) {
	#ifdef INET6
	case 6:
	ip6 = (struct ip6_hdr *)bp2;
	/* we do not attempt to decrypt jumbograms */
	if (!EXTRACT_16BITS(&ip6->ip6_plen))
	goto fail;
	/* if we can't get nexthdr, we do not need to decrypt it */
	len = sizeof(struct ip6_hdr) + EXTRACT_16BITS(&ip6->ip6_plen);

	/* see if we can find the SA, and if so, decode it */
	for (sa = sa_list_head; sa != NULL; sa = sa->next) {
	struct sockaddr_in6 sin6 = (struct sockaddr_in6 )&sa->daddr;
	if (sa->spi == ntohl(esp->esp_spi) &&
	sin6->sin6_family == AF_INET6 &&
	memcmp(&sin6->sin6_addr, &ip6->ip6_dst,
	sizeof(struct in6_addr)) == 0) {
	break;
	}
	}
	break;
	#endif /INET6/
	case 4:
	/* nexthdr & padding are in the last fragment */
	if (EXTRACT_16BITS(&ip->ip_off) & IP_MF)
	goto fail;
	len = EXTRACT_16BITS(&ip->ip_len);

	/* see if we can find the SA, and if so, decode it */
	for (sa = sa_list_head; sa != NULL; sa = sa->next) {
	struct sockaddr_in sin = (struct sockaddr_in )&sa->daddr;
	if (sa->spi == ntohl(esp->esp_spi) &&
	sin->sin_family == AF_INET &&
	sin->sin_addr.s_addr == ip->ip_dst.s_addr) {
	break;
	}
	}
	break;
	default:
	goto fail;
	}

	/* if we didn't find the specific one, then look for
	* an unspecified one.
	*/
	if(sa == NULL) {
	sa = sa_default;
	}

	/* if not found fail */
	if(sa == NULL)
	goto fail;

	/* if we can't get nexthdr, we do not need to decrypt it */
	if (ep - bp2 < len)
	goto fail;
	if (ep - bp2 > len) {
	/* FCS included at end of frame (NetBSD 1.6 or later) */
	ep = bp2 + len;
	}

	ivoff = (u_char *)(esp + 1) + sa->xform->replaysize;
	ivlen = sa->xform->ivlen;
	secret = sa->secret;
	espsecret_keylen = sa->secretlen;

	switch (sa->xform->algo) {
	case DESCBC:
	#ifdef HAVE_LIBCRYPTO
	{
	u_char iv[8];
	#if OPENSSL_VERSION_NUMBER >= 0x00907000L
	DES_key_schedule schedule;
	#else
	des_key_schedule schedule;
	#endif

	switch (ivlen) {
	case 4:
	memcpy(iv, ivoff, 4);
	memcpy(&iv[4], ivoff, 4);
	p = &iv[4];
	*p++ ^= 0xff;
	*p++ ^= 0xff;
	*p++ ^= 0xff;
	*p++ ^= 0xff;
	break;
	case 8:
	memcpy(iv, ivoff, 8);
	break;
	default:
	goto fail;
	}
	p = ivoff + ivlen;

	if (espsecret_keylen != 8)
	goto fail;

	#if OPENSSL_VERSION_NUMBER >= 0x00908000L
	DES_set_key_unchecked((const_DES_cblock *)secret, &schedule);

	DES_cbc_encrypt((const unsigned char *)p, p,
	(long)(ep - p), &schedule, (DES_cblock *)iv,
	DES_DECRYPT);

	#elif OPENSSL_VERSION_NUMBER >= 0x00907000L
	DES_set_key_unchecked((DES_cblock *)secret, schedule);

	DES_cbc_encrypt((const unsigned char *)p, p,
	(long)(ep - p), schedule, (DES_cblock *)iv,
	DES_DECRYPT);
	#else
	des_check_key = 0;
	des_set_key((void *)secret, schedule);

	des_cbc_encrypt((void )p, (void )p,
	(long)(ep - p), schedule, (void *)iv,
	DES_DECRYPT);
	#endif
	advance = ivoff - (u_char *)esp + ivlen;
	break;
	}
	#else
	goto fail;
	#endif /HAVE_LIBCRYPTO/

	case BLOWFISH:
	#ifdef HAVE_LIBCRYPTO
	{
	BF_KEY schedule;

	if (espsecret_keylen < 5 \|\| espsecret_keylen > 56)
	goto fail;
	BF_set_key(&schedule, espsecret_keylen, secret);

	p = ivoff + ivlen;
	BF_cbc_encrypt(p, p, (long)(ep - p), &schedule, ivoff,
	BF_DECRYPT);
	advance = ivoff - (u_char *)esp + ivlen;
	break;
	}
	#else
	goto fail;
	#endif /HAVE_LIBCRYPTO/

	case RC5:
	#if defined(HAVE_LIBCRYPTO) && defined(HAVE_RC5_H)
	{
	RC5_32_KEY schedule;

	if (espsecret_keylen < 5 \|\| espsecret_keylen > 255)
	goto fail;
	RC5_32_set_key(&schedule, espsecret_keylen, secret,
	RC5_16_ROUNDS);

	p = ivoff + ivlen;
	RC5_32_cbc_encrypt(p, p, (long)(ep - p), &schedule, ivoff,
	RC5_DECRYPT);
	advance = ivoff - (u_char *)esp + ivlen;
	break;
	}
	#else
	goto fail;
	#endif /HAVE_LIBCRYPTO/

	case CAST128:
	#if defined(HAVE_LIBCRYPTO) && defined(HAVE_CAST_H) && !defined(HAVE_BUGGY_CAST128)
	{
	CAST_KEY schedule;

	if (espsecret_keylen < 5 \|\| espsecret_keylen > 16)
	goto fail;
	CAST_set_key(&schedule, espsecret_keylen, secret);

	p = ivoff + ivlen;
	CAST_cbc_encrypt(p, p, (long)(ep - p), &schedule, ivoff,
	CAST_DECRYPT);
	advance = ivoff - (u_char *)esp + ivlen;
	break;
	}
	#else
	goto fail;
	#endif /HAVE_LIBCRYPTO/

	case DES3CBC:
	#if defined(HAVE_LIBCRYPTO)
	{
	#if OPENSSL_VERSION_NUMBER >= 0x00907000L
	DES_key_schedule s1, s2, s3;

	if (espsecret_keylen != 24)
	goto fail;
	DES_set_odd_parity((DES_cblock *)secret);
	DES_set_odd_parity((DES_cblock *)(secret + 8));
	DES_set_odd_parity((DES_cblock *)(secret + 16));
	#if OPENSSL_VERSION_NUMBER >= 0x00908000L
	if(DES_set_key_checked((const_DES_cblock *)secret, &s1) != 0) {
	printf("failed to schedule key 1\n");
	}
	if(DES_set_key_checked((const_DES_cblock *)(secret + 8), &s2)!=0) {
	printf("failed to schedule key 2\n");
	}
	if(DES_set_key_checked((const_DES_cblock *)(secret + 16), &s3)!=0) {
	printf("failed to schedule key 3\n");
	}
	#else
	if(DES_set_key_checked((DES_cblock *)secret, s1) != 0) {
	printf("failed to schedule key 1\n");
	}
	if(DES_set_key_checked((DES_cblock *)(secret + 8), s2)!=0) {
	printf("failed to schedule key 2\n");
	}
	if(DES_set_key_checked((DES_cblock *)(secret + 16), s3)!=0) {
	printf("failed to schedule key 3\n");
	}
	#endif

	p = ivoff + ivlen;
	DES_ede3_cbc_encrypt((const unsigned char *)p, p,
	(long)(ep - p),
	&s1, &s2, &s3,
	(DES_cblock *)ivoff, DES_DECRYPT);
	#else
	des_key_schedule s1, s2, s3;

	if (espsecret_keylen != 24)
	goto fail;
	des_check_key = 1;
	des_set_odd_parity((void *)secret);
	des_set_odd_parity((void *)(secret + 8));
	des_set_odd_parity((void *)(secret + 16));
	if(des_set_key((void *)secret, s1) != 0) {
	printf("failed to schedule key 1\n");
	}
	if(des_set_key((void *)(secret + 8), s2)!=0) {
	printf("failed to schedule key 2\n");
	}
	if(des_set_key((void *)(secret + 16), s3)!=0) {
	printf("failed to schedule key 3\n");
	}

	p = ivoff + ivlen;
	des_ede3_cbc_encrypt((void )p, (void )p,
	(long)(ep - p),
	s1, s2, s3,
	(void *)ivoff, DES_DECRYPT);
	#endif
	advance = ivoff - (u_char *)esp + ivlen;
	break;
	}
	#else
	goto fail;
	#endif /HAVE_LIBCRYPTO/

	case NONE:
	default:
	advance = sizeof(struct newesp) + sa->xform->replaysize;
	break;
	}

	ep = ep - sa->xform->authlen;
	/* sanity check for pad length */
	if (ep - bp < *(ep - 2))
	goto fail;

	if (padlen)
	padlen = (ep - 2) + 2;

	if (nhdr)
	nhdr = (ep - 1);

	printf(": ");
	return advance;

	fail:
	if (nhdr)
	*nhdr = -1;
	return 65536;
	}