Ethereal-dev: RE: [Ethereal-dev] IPsec Dissector to decrypt ESP Payload
Note: This archive is from the project's previous web site, ethereal.com. This list is no longer active.
From: "Frederic Roudaut" <frederic.roudaut@xxxxxxxx>
Date: Sat, 25 Feb 2006 14:02:06 +0100 (CET)
Hi I just add a #define __USE_LIBGCRYPT__ that you have to set to be able to decrypt ESP payload. Otherwise if not, the original IPSEC dissector is compiled. I also notice that on current stable Ethereal versions gnutls is not linked. Thus you have to install libgcrypt and do: LDFLAGS=-lgcrypt ./configure && make For windows you should get: http://gnunet.org/download/win/libgcrypt-1.2.1.zip and do something similar. Best regards --- Frederic > Paolo, > > is there a way to compile the dissector with windows. The sourceforge rep > (gnutls-win32-msvc.tgz) does not include the winposixtype.h and the > gcrypt.h. > > TIA > > Thomas > > >> --- Ursprüngliche Nachricht --- >> Von: "Filonenko Alexander-AAF013" <AAF013@xxxxxxxxxxxx> >> An: "Ethereal development" <ethereal-dev@xxxxxxxxxxxx> >> Betreff: RE: [Ethereal-dev] IPsec Dissector to decrypt ESP Payload >> Datum: Fri, 24 Feb 2006 17:42:44 -0500 >> >> Frederic, >> >> I find IPsec functionality you have added to the dissector very useful. >> Hope I can provide you with some feedback in a few weeks. >> >> Thank you, >> Alex Filonenko >> >> > -----Original Message----- >> > From: ethereal-dev-bounces@xxxxxxxxxxxx >> > [mailto:ethereal-dev-bounces@xxxxxxxxxxxx] On Behalf Of >> > Frederic Roudaut >> > Sent: Friday, February 24, 2006 10:01 AM >> > To: Ethereal development >> > Subject: [Ethereal-dev] IPsec Dissector to decrypt ESP Payload >> > >> > >> > Hi, >> > >> > finally, I have updated my dissector using libgcrypt. >> > It does not use openssl anymore. >> > If gnutls is installed, all should work. >> > Thus, now it should decrypt and dissect >> > (transport/tunnel/several encapsulations ...) : >> > >> > - NULL Encryption Algorithm >> > - TripleDES-CBC [RFC2451] : keylen 192 bits. >> > - AES-CBC with 128-bit keys [RFC3602] : keylen 128 and 192/256 bits. >> > - AES-CTR [RFC3686] : keylen 160/224/288 bits. The remaining >> > 32 bits will be used as nonce. >> > - DES-CBC [RFC2405] : keylen 64 bits >> > >> > I also have added : >> > >> > - BLOWFISH-CBC : keylen 128 bits. >> > - TWOFISH-CBC : keylen 128/256 bits. >> > >> > You have to indicate the Authentication algorithm even if all >> > Algorithms since it uses 12 bytes in the Auth field should >> > work (have a look to the README to understand why I put it >> > ;-) ). If you consider I have to throw it away please tell me. >> > >> > HMAC-SHA1-96 [RFC2404] >> > NULL >> > AES-XCBC-MAC-96 [RFC3566] >> > HMAC-MD5-96 [RFC2403] >> > >> > In the attachment you will get : >> > - this dissector >> > - a new README >> > - some example capture files with associated preferences >> > files (and setkey config files) >> > >> > >> > Best Regards, >> > >> > >> > ---- >> > Frederic >> > >> > >> > >> > >> > >> > >> > -- >> > Frédéric ROUDAUT >> > IRISA-INRIA, Campus de Beaulieu, 35042 Rennes cedex, France >> > Tl: +33 (0) 2 99 84 71 44, Fax: +33 (0) 2 99 84 71 71 >> > >> > >> _______________________________________________ >> Ethereal-dev mailing list >> Ethereal-dev@xxxxxxxxxxxx >> http://www.ethereal.com/mailman/listinfo/ethereal-dev >> > > -- > DSL-Aktion wegen großer Nachfrage bis 28.2.2006 verlängert: > GMX DSL-Flatrate 1 Jahr kostenlos* http://www.gmx.net/de/go/dsl > _______________________________________________ > Ethereal-dev mailing list > Ethereal-dev@xxxxxxxxxxxx > http://www.ethereal.com/mailman/listinfo/ethereal-dev >
/* packet-ipsec.c
* Routines for IPsec/IPComp packet disassembly
*
* $Id: packet-ipsec.c 14786 2005-06-26 19:56:52Z guy $
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@xxxxxxxxxxxx>
* Copyright 1998 Gerald Combs
*
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU 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.
*/
/*
Addon:
Frederic ROUDAUT (frederic.roudaut@xxxxxxx)
Copyright 2006 Frederic ROUDAUT
- Decrypt ESP Payload with the following Algorithms defined in RFC 4305:
Encryption Algorithm
--------------------
NULL
TripleDES-CBC [RFC2451] : keylen 192 bits.
AES-CBC with 128-bit keys [RFC3602] : keylen 128 and 192/256 bits.
AES-CTR [RFC3686] : keylen 160/224/288 bits. The remaining 32 bits will be used as nonce.
DES-CBC [RFC2405] : keylen 64 bits
Authentication Algorithm (in fact all Algorithms since it uses 12 bytes in the Auth field)
------------------------
HMAC-SHA1-96 [RFC2404]
NULL
AES-XCBC-MAC-96 [RFC3566]
HMAC-MD5-96 [RFC2403]
- Add ESP Payload Decryption support for the following Encryption Algorithms :
[BLOWFISH-CBC] : keylen 128 bits.
[TWOFISH-CBC] : keylen 128/256 bits.
*/
/* If you want to be able to decrypt ESP packets you MUST define this : */
#define __USE_LIBGCRYT__
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdio.h>
#include <string.h>
#include <glib.h>
#include <epan/packet.h>
#include "packet-ipsec.h"
#include <epan/addr_resolv.h>
#include <epan/ipproto.h>
#include <epan/prefs.h>
#include <ctype.h>
#ifdef __USE_LIBGCRYT__
#include <gcrypt.h>
#endif
static int proto_ah = -1;
static int hf_ah_spi = -1;
static int hf_ah_sequence = -1;
static int proto_esp = -1;
static int hf_esp_spi = -1;
static int hf_esp_sequence = -1;
static int hf_esp_pad = -1;
static int hf_esp_protocol = -1;
static int proto_ipcomp = -1;
static int hf_ipcomp_flags = -1;
static int hf_ipcomp_cpi = -1;
static gint ett_ah = -1;
static gint ett_esp = -1;
static gint ett_ipcomp = -1;
static dissector_handle_t data_handle;
static dissector_table_t ip_dissector_table;
#ifdef __USE_LIBGCRYT__
/* Encryption algorithms defined in RFC 4305 */
#define IPSEC_ENCRYPT_NULL 0
#define IPSEC_ENCRYPT_3DES_CBC 1
#define IPSEC_ENCRYPT_AES_CBC 2
#define IPSEC_ENCRYPT_AES_CTR 3
#define IPSEC_ENCRYPT_DES_CBC 4
#define IPSEC_ENCRYPT_BLOWFISH_CBC 5
#define IPSEC_ENCRYPT_TWOFISH_CBC 6
/* Authentication algorithms defined in RFC 4305 */
#define IPSEC_AUTH_NULL 0
#define IPSEC_AUTH_HMAC_SHA1_96 1
#define IPSEC_AUTH_AES_XCBC_MAC_96 2
#define IPSEC_AUTH_HMAC_MD5_96 3
#endif
/* well-known algorithm number (in CPI), from RFC2409 */
#define IPCOMP_OUI 1 /* vendor specific */
#define IPCOMP_DEFLATE 2 /* RFC2394 */
#define IPCOMP_LZS 3 /* RFC2395 */
#define IPCOMP_MAX 4
#ifdef __USE_LIBGCRYT__
#define IPSEC_IPV6_ADDR_LEN 128
#define IPSEC_IPV4_ADDR_LEN 32
#define IPSEC_STRLEN_IPV6 32
#define IPSEC_STRLEN_IPV4 8
#define IPSEC_SA_IPV4 1
#define IPSEC_SA_IPV6 2
#define IPSEC_SA_UNKNOWN -1
#define IPSEC_SA_WILDCARDS_ANY '*'
#define IPSEC_SA_SEPARATOR '|'
#define IPSEC_SA_ADDR_LEN_SEPARATOR '/'
/* Number of Security Associations */
#define IPSEC_NB_SA 5
#endif
static const value_string cpi2val[] = {
{ IPCOMP_OUI, "OUI" },
{ IPCOMP_DEFLATE, "DEFLATE" },
{ IPCOMP_LZS, "LZS" },
{ 0, NULL },
};
struct newah {
guint8 ah_nxt; /* Next Header */
guint8 ah_len; /* Length of data + 1, in 32bit */
guint16 ah_reserve; /* Reserved for future use */
guint32 ah_spi; /* Security parameter index */
guint32 ah_seq; /* Sequence number field */
/* variable size, 32bit bound*/ /* Authentication data */
};
struct newesp {
guint32 esp_spi; /* ESP */
guint32 esp_seq; /* Sequence number */
/*variable size*/ /* (IV and) Payload data */
/*variable size*/ /* padding */
/*8bit*/ /* pad size */
/*8bit*/ /* next header */
/*8bit*/ /* next header */
/*variable size, 32bit bound*/ /* Authentication data */
};
struct ipcomp {
guint8 comp_nxt; /* Next Header */
guint8 comp_flags; /* Must be zero */
guint16 comp_cpi; /* Compression parameter index */
};
#ifdef __USE_LIBGCRYT__
/* SA Paramaters and SAD */
static guint g_esp_nb_sa = IPSEC_NB_SA;
static guint g_max_esp_size_nb_sa = 3;
static guint g_max_esp_nb_sa = 100;
typedef struct {
const gchar *sa;
gint typ;
gchar *src;
gint src_len;
gchar *dst;
gint dst_len;
gchar *spi;
gint encryption_algo;
gint authentication_algo;
const gchar *encryption_key;
/************** UNCOMMENT THIS PART IF YOU WANT TO ADD CHECKING OF AUTHENTICATION *********************/
/*
const gchar *authentication_key;
*/
/************** UNCOMMENT THIS PART IF YOU WANT TO ADD CHECKING OF AUTHENTICATION *********************/
gboolean is_valid;
} g_esp_sa;
typedef struct {
gint nb;
g_esp_sa table[IPSEC_NB_SA];
} g_esp_sa_database;
static g_esp_sa_database g_esp_sad;
/* Default ESP payload decode to off */
static gboolean g_esp_enable_encryption_decode = FALSE;
#endif
/*
Default ESP payload heuristic decode to off
(only works if payload is NULL encrypted and ESP payload decode is off or payload is NULL encrypted
and the packet does not match a Security Association).
*/
static gboolean g_esp_enable_null_encryption_decode_heuristic = FALSE;
/* Place AH payload in sub tree */
static gboolean g_ah_payload_in_subtree = FALSE;
#ifndef offsetof
#define offsetof(type, member) ((size_t)(&((type *)0)->member))
#endif
/*
Name : static int get_ipv6_suffix(char* ipv6_suffix, char *ipv6_address)
Description : Get the extended IPv6 Suffix of an IPv6 Address
Return : Return the number of char of the IPv6 address suffix parsed
Params:
- char *ipv6_address : the valid ipv6 address to parse in char *
- char *ipv6_suffix : the ipv6 suffix associated in char *
ex: if IPv6 address is "3ffe::1" the IPv6 suffix will be "0001" and the function will return 3
*/
#ifdef __USE_LIBGCRYT__
static int get_ipv6_suffix(char* ipv6_suffix, char *ipv6_address)
{
char suffix[IPSEC_STRLEN_IPV6 + 1];
int cpt = 0;
int cpt_suffix = 0;
int cpt_seg = 0;
int j =0;
int ipv6_len = 0;
gboolean found = FALSE;
ipv6_len = strlen(ipv6_address);
if(ipv6_len == 0)
{
/* Found a suffix */
found = TRUE;
}
else
{
while ( (cpt_suffix < IPSEC_STRLEN_IPV6) && (ipv6_len - cpt -1 >= 0) && (found == FALSE))
{
if(ipv6_address[ipv6_len - cpt - 1] == ':')
{
/* Add some 0 to the prefix; */
for(j = cpt_seg; j < 4; j++)
{
suffix[IPSEC_STRLEN_IPV6 -1 -cpt_suffix] = '0';
cpt_suffix ++;
}
cpt_seg = 0;
if(ipv6_len - cpt - 1 == 0)
{
/* Found a suffix */
found = TRUE;
}
else
if(ipv6_address[ipv6_len - cpt - 2] == ':')
{
/* found a suffix */
cpt +=2;
found = TRUE;
}
else
{
cpt++;
}
}
else
{
suffix[IPSEC_STRLEN_IPV6 -1 -cpt_suffix] = toupper(ipv6_address[ipv6_len - cpt - 1]);
cpt_seg ++;
cpt_suffix ++;
cpt++;
}
}
if(cpt_suffix % 4 != 0)
{
for(j = cpt_seg; j < 4; j++)
{
suffix[IPSEC_STRLEN_IPV6 -1 -cpt_suffix] = '0';
cpt_suffix ++;
}
cpt_seg = 0;
}
}
for(j = 0 ; j < cpt_suffix ; j ++)
{
suffix[j] = suffix[j + IPSEC_STRLEN_IPV6 - cpt_suffix] ;
}
suffix[j] = '\0';
memcpy(ipv6_suffix,suffix,j + 1);
return cpt;
}
#endif
/*
Name : static int get_full_ipv6_addr(char* ipv6_addr_expanded, char *ipv6_addr)
Description : Get the extended IPv6 Address of an IPv6 Address
Return : Return the remaining number of char of the IPv6 address parsed
Params:
- char *ipv6_addr : the valid ipv6 address to parse in char *
- char *ipv6_addr_expansed : the expanded ipv6 address associated in char *
ex: if IPv6 address is "3ffe::1" the IPv6 expanded address will be "3FFE0000000000000000000000000001" and the function will return 0
if IPV6 address is "3ffe::*" the IPv6 expanded address will be "3FFE000000000000000000000000****" and the function will return 0
*/
#ifdef __USE_LIBGCRYT__
static int
get_full_ipv6_addr(char* ipv6_addr_expanded, char *ipv6_addr)
{
char suffix[IPSEC_STRLEN_IPV6 + 1];
char prefix[IPSEC_STRLEN_IPV6 + 1];
int suffix_cpt = 0;
int suffix_len = 0;
int prefix_remaining = 0;
int prefix_len = 0;
int j = 0;
if((ipv6_addr == NULL) || (strcmp(ipv6_addr, "") == 0)) return -1;
if((strlen(ipv6_addr) == 1) && (ipv6_addr[0] == IPSEC_SA_WILDCARDS_ANY))
{
for(j = 0; j <= IPSEC_STRLEN_IPV6; j++)
{
ipv6_addr_expanded[j] = IPSEC_SA_WILDCARDS_ANY;
}
ipv6_addr_expanded[IPSEC_STRLEN_IPV6] = '\0';
return 0;
}
suffix_cpt = get_ipv6_suffix(suffix,ipv6_addr);
suffix_len = strlen(suffix);
if(suffix_len < IPSEC_STRLEN_IPV6)
{
char prefix_addr[strlen(ipv6_addr) - suffix_cpt + 1];
memcpy(prefix_addr,ipv6_addr,strlen(ipv6_addr) - suffix_cpt);
prefix_addr[strlen(ipv6_addr) - suffix_cpt] = '\0';
prefix_remaining = get_ipv6_suffix(prefix,prefix_addr);
prefix_len = strlen(prefix);
memcpy(ipv6_addr_expanded,prefix,prefix_len);
}
for(j = 0; j <= IPSEC_STRLEN_IPV6 - prefix_len - suffix_len; j++)
{
ipv6_addr_expanded[j + prefix_len] = '0';
}
memcpy(ipv6_addr_expanded + IPSEC_STRLEN_IPV6 - suffix_len, suffix,suffix_len + 1);
if(suffix_len < IPSEC_STRLEN_IPV6)
return (prefix_len - prefix_remaining);
else
return strlen(ipv6_addr) - suffix_cpt;
}
#endif
/*
Name : static gboolean get_full_ipv4_addr(char* ipv4_addr_expanded, char *ipv4_addr)
Description : Get the extended IPv4 Address of an IPv4 Address
Return : Return true if it can derive an IPv4 address. It does not mean that the previous one was valid.
Params:
- char *ipv4_addr : the valid ipv4 address to parse in char *
- char *ipv4_addr_expansed : the expanded ipv4 address associated in char *
ex: if IPv4 address is "190.*.*.1" the IPv4 expanded address will be "BE****01" and the function will return 0
if IPv4 address is "*" the IPv4 expanded address will be "********" and the function will return 0
*/
#ifdef __USE_LIBGCRYT__
static gboolean
get_full_ipv4_addr(char* ipv4_addr_expanded, char *ipv4_addr)
{
char addr_byte_string_tmp[4];
char addr_byte_string[4];
guint addr_byte = 0;
guint i = 0;
guint j = 0;
guint k = 0;
guint cpt = 0;
gboolean done_flag = FALSE;
if((ipv4_addr == NULL) || (strcmp(ipv4_addr, "") == 0)) return done_flag;
if((strlen(ipv4_addr) == 1) && (ipv4_addr[0] == IPSEC_SA_WILDCARDS_ANY))
{
for(i = 0; i <= IPSEC_STRLEN_IPV4; i++)
{
ipv4_addr_expanded[i] = IPSEC_SA_WILDCARDS_ANY;
}
ipv4_addr_expanded[IPSEC_STRLEN_IPV4] = '\0';
done_flag = TRUE;
}
else {
j = 0;
cpt = 0;
k = 0;
while((done_flag == FALSE) && (j <= strlen(ipv4_addr)) && (cpt < IPSEC_STRLEN_IPV4))
{
if(j == strlen(ipv4_addr))
{
addr_byte_string_tmp[k] = '\0';
if((strlen(addr_byte_string_tmp) == 1) && (addr_byte_string_tmp[0] == IPSEC_SA_WILDCARDS_ANY))
{
for(i = 0; i < 2; i++)
{
ipv4_addr_expanded[cpt] = IPSEC_SA_WILDCARDS_ANY;
cpt ++;
}
}
else
{
sscanf(addr_byte_string_tmp,"%i",&addr_byte);
if(addr_byte < 16) g_snprintf(addr_byte_string,4,"0%X",addr_byte);
else g_snprintf(addr_byte_string,4,"%X",addr_byte);
for(i = 0; i < strlen(addr_byte_string); i++)
{
ipv4_addr_expanded[cpt] = addr_byte_string[i];
cpt ++;
}
}
done_flag = TRUE;
}
else if(ipv4_addr[j] == '.')
{
addr_byte_string_tmp[k] = '\0';
if((strlen(addr_byte_string_tmp) == 1) && (addr_byte_string_tmp[0] == IPSEC_SA_WILDCARDS_ANY))
{
for(i = 0; i < 2; i++)
{
ipv4_addr_expanded[cpt] = IPSEC_SA_WILDCARDS_ANY;
cpt ++;
}
}
else
{
sscanf(addr_byte_string_tmp,"%i",&addr_byte);
if(addr_byte < 16) g_snprintf(addr_byte_string,4,"0%X",addr_byte);
else g_snprintf(addr_byte_string,4,"%X",addr_byte);
for(i = 0; i < strlen(addr_byte_string); i++)
{
ipv4_addr_expanded[cpt] = addr_byte_string[i];
cpt ++;
}
}
k = 0;
j++;
}
else
{
if(k >= 3)
{
/* Incorrect IPv4 Address. Erase previous Values in the Byte. (LRU mechanism) */
addr_byte_string_tmp[0] = ipv4_addr[j];
k = 1;
j++;
}
else
{
addr_byte_string_tmp[k] = ipv4_addr[j];
k++;
j++;
}
}
}
ipv4_addr_expanded[cpt] = '\0';
}
return done_flag;
}
#endif
/*
Name : static gboolean esp_sa_parse_ipv6addr(const gchar *sa, guint index_start, gchar **pt_ipv6addr, guint *index_end)
Description : Get the IPv6 address of a Security Association
Return : Return true if it can get an address. It does not mean that the address is valid.
Params:
- char *sa : the Security Association in char *
- guint index_start : the index to start to find the address
- gchar **pt_ipv6addr : the address found. The Allocation is done here !
- guint *index_end : the last index of the address
*/
#ifdef __USE_LIBGCRYT__
static gboolean
esp_sa_parse_ipv6addr(const gchar *sa, guint index_start, gchar **pt_ipv6addr, guint *index_end)
{
guint cpt = 0;
guint strlen_max = 40;
char addr_string[strlen_max];
gboolean done_flag = FALSE;
if((sa == NULL) || (strcmp(sa, "") == 0)) return FALSE;
/* Get Address */
while(((cpt + index_start) < strlen(sa)) && (done_flag == FALSE) && (cpt <= strlen_max))
{
if((sa[cpt + index_start] == IPSEC_SA_SEPARATOR) || (sa[cpt + index_start] == IPSEC_SA_ADDR_LEN_SEPARATOR))
{
if(cpt == 0) return FALSE;
*index_end = cpt + index_start;
addr_string[cpt] = '\0';
done_flag = TRUE;
}
else
{
if((cpt == strlen_max - 1) && ((cpt + index_start) < strlen(sa)) && (sa[cpt + index_start + 1] != IPSEC_SA_ADDR_LEN_SEPARATOR) && (sa[cpt + index_start + 1] != IPSEC_SA_SEPARATOR)) return FALSE;
addr_string[cpt] = toupper(sa[cpt + index_start]);
cpt ++;
}
}
if(done_flag)
{
*pt_ipv6addr = (gchar *)g_malloc((strlen(addr_string) + 1) * sizeof(gchar));
memcpy(*pt_ipv6addr,addr_string,strlen(addr_string) + 1);
}
return done_flag;
}
#endif
/*
Name : static gboolean esp_sa_parse_ipv4addr(const gchar *sa, guint index_start, gchar **pt_ipv4addr, guint *index_end)
Description : Get the IPv4 address of a Security Association
Return : Return true if it can get an address. It does not mean that the address is valid.
Params:
- char *sa : the Security Association in char *
- guint index_start : the index to start to find the address
- gchar **pt_ipv4addr : the address found. The Allocation is done here !
- guint *index_end : the last index of the address
*/
#ifdef __USE_LIBGCRYT__
static gboolean
esp_sa_parse_ipv4addr(const gchar *sa, guint index_start, gchar **pt_ipv4addr, guint *index_end)
{
guint cpt = 0;
guint strlen_max = 16;
char addr_string[strlen_max];
gboolean done_flag = FALSE;
if((sa == NULL) || (strcmp(sa, "") == 0)) return FALSE;
/* Get Address */
while(((cpt + index_start) < strlen(sa)) && (done_flag == FALSE) && (cpt <= strlen_max))
{
if((sa[cpt + index_start] == IPSEC_SA_SEPARATOR) || (sa[cpt + index_start] == IPSEC_SA_ADDR_LEN_SEPARATOR))
{
if(cpt == 0) return FALSE;
*index_end = cpt + index_start;
addr_string[cpt] = '\0';
done_flag = TRUE;
}
else
{
if((cpt == strlen_max - 1) && ((cpt + index_start) < strlen(sa)) && (sa[cpt + index_start + 1] != IPSEC_SA_ADDR_LEN_SEPARATOR) && (sa[cpt + index_start + 1] != IPSEC_SA_SEPARATOR)) return FALSE;
addr_string[cpt] = toupper(sa[cpt + index_start]);
cpt ++;
}
}
if(done_flag)
{
*pt_ipv4addr = (gchar *)g_malloc((strlen(addr_string) + 1) * sizeof(gchar));
memcpy(*pt_ipv4addr,addr_string,strlen(addr_string) + 1);
}
return done_flag;
}
#endif
/*
Name : static gboolean esp_sa_parse_spi(const gchar *sa, guint index_start, gchar **pt_spi, guint *index_end)
Description : Get the SPI of a Security Association
Return : Return true if it can get a SPI. It does not mean that the SPI is valid.
Params:
- char *sa : the Security Association in char *
- guint index_start : the index to start to find the spi
- gchar **pt_spi : the spi found. The Allocation is done here !
- guint *index_end : the last index of the address
*/
#ifdef __USE_LIBGCRYT__
static gboolean
esp_sa_parse_spi(const gchar *sa, guint index_start, gchar **pt_spi, guint *index_end)
{
guint cpt = 0;
guint spi_len_max = 10;
guint32 spi = 0;
guint i = 0;
gchar spi_string[spi_len_max];
gchar spi_string_tmp[spi_len_max];
gboolean done_flag = FALSE;
if((sa == NULL) || (strcmp(sa, "") == 0)) return FALSE;
while(((cpt + index_start) < strlen(sa)) && (done_flag == FALSE) && (cpt <= spi_len_max))
{
spi_string[cpt] = toupper(sa[cpt + index_start]);
cpt ++;
}
if(cpt == 0) done_flag = FALSE;
else
{
spi_string[cpt] = '\0';
if((cpt >= 2) &&
(spi_string[0] == '0') &&
(spi_string[1] == 'X'))
{
for(i = 0; i <= cpt - 2; i++) spi_string_tmp[i] = spi_string[i+2];
sscanf(spi_string_tmp,"%x",&spi);
g_snprintf(spi_string,spi_len_max,"%i",spi);
}
*index_end = cpt + index_start - 1;
*pt_spi = (gchar *)g_malloc((strlen(spi_string) + 1) * sizeof(gchar));
memcpy(*pt_spi, spi_string, strlen(spi_string) + 1);
done_flag = TRUE;
}
return done_flag;
}
#endif
/*
Name : static gboolean esp_sa_parse_protocol_typ(const gchar *sa, guint index_start, gint *pt_protocol_typ, guint *index_end)
Description : Get the Protocol Type of a Security Association
Return : Return true if it can get a valid protocol type.
Params:
- char *sa : the Security Association in char *
- guint index_start : the index to start to find the protocol type
- gint *pt_protocol_typ : the protocl type found. Either IPv4, Either IPv6 (IPSEC_SA_IPV4, IPSEC_SA_IPV6)
- guint *index_end : the last index of the protocol type
*/
#ifdef __USE_LIBGCRYT__
static gboolean
esp_sa_parse_protocol_typ(const gchar *sa, guint index_start, gint *pt_protocol_typ, guint *index_end)
{
guint cpt = 0;
guint typ_len_max = 4;
gchar typ_string[typ_len_max];
gboolean done_flag = FALSE;
*pt_protocol_typ = IPSEC_SA_UNKNOWN;
if((sa == NULL) || (strcmp(sa, "") == 0)) return FALSE;
while(((cpt + index_start) < strlen(sa)) && (done_flag == FALSE) && (cpt <= typ_len_max) && (sa[cpt + index_start] != IPSEC_SA_SEPARATOR))
{
typ_string[cpt] = toupper(sa[cpt + index_start]);
cpt ++;
}
if(cpt == 0) done_flag = FALSE;
else
{
typ_string[cpt] = '\0';
if(strcmp(typ_string, "IPV6") == 0)
{
*pt_protocol_typ = IPSEC_SA_IPV6;
done_flag = TRUE;
}
else if (strcmp(typ_string, "IPV4") == 0)
{
*pt_protocol_typ = IPSEC_SA_IPV4;
done_flag = TRUE;
}
else
{
*pt_protocol_typ = IPSEC_SA_UNKNOWN;
done_flag = FALSE;
}
*index_end = cpt + index_start + 1;
}
return done_flag;
}
#endif
/*
Name : static gboolean esp_sa_parse_addr_len(const gchar *sa, guint index_start, guint *len, guint *index_end)
Description : Get the Address Length of an address (IPv4/IPv6)
Return : Return true if it can get an Address Length. It does not mean that the length is valid
Params:
- char *sa : the Security Association in char *
- guint index_start : the index to start to find the length
- guint *len : the address length found. If none -1 is given.
- guint *index_end : the last index of the address length in the SA
*/
#ifdef __USE_LIBGCRYT__
static gboolean
esp_sa_parse_addr_len(const gchar *sa, guint index_start, guint *len, guint *index_end)
{
guint cpt = 0;
guint strlen_max = 3;
char len_string[strlen_max];
gboolean done_flag = FALSE;
*len = -1;
if((sa == NULL) || (strcmp(sa, "") == 0)) return FALSE;
if(sa[index_start] == IPSEC_SA_SEPARATOR)
{
*index_end = index_start + 1;
*len = -1;
done_flag = TRUE;
}
else if(sa[index_start] == IPSEC_SA_ADDR_LEN_SEPARATOR)
{
cpt ++;
while(((cpt + index_start) < strlen(sa)) && (done_flag == FALSE) && (cpt <= strlen_max + 1))
{
if(sa[cpt + index_start] == IPSEC_SA_SEPARATOR)
{
if(cpt == 1)
{
*index_end = index_start + cpt + 1;
*len = -1;
done_flag = TRUE;
}
else
{
*index_end = cpt + index_start + 1;
len_string[cpt - 1] = '\0';
*len = atoi(len_string);
done_flag = TRUE;
}
}
else
{
if((cpt == strlen_max) && ((cpt + index_start) < strlen(sa)) && (sa[cpt + index_start + 1] != IPSEC_SA_ADDR_LEN_SEPARATOR) && (sa[cpt + index_start + 1] != IPSEC_SA_SEPARATOR)) return FALSE;
len_string[cpt -1] = sa[cpt + index_start];
cpt ++;
}
}
}
return done_flag;
}
#endif
/*
Name : esp_sa_remove_white(const gchar *sa, gchar **sa_bis)
Description : Remote White Space in a SA
Parse a Security Association and give the SA without space.
There is no need to allocate memory before the call. All is done !
Return : Void
Params:
- char *sa : the Security Association in char *
- char **sa_bis : the Security Association in char * without white space
*/
#ifdef __USE_LIBGCRYT__
static void
esp_sa_remove_white(const gchar *sa, gchar **sa_bis)
{
int i = 0;
int cpt = 0;
gchar sa_tmp[strlen(sa)];
if((sa == NULL) || (strcmp(sa, "") == 0))
{
*sa_bis = NULL;
return;
}
else
for(i = 0; (unsigned int) i < strlen(sa); i++)
{
if((sa[i] != ' ') && (sa[i] != '\t'))
{
sa_tmp[cpt] = sa[i];
cpt ++;
}
}
sa_tmp[cpt] = '\0';
*sa_bis = (gchar *)g_malloc((cpt +1) * sizeof(gchar));
memcpy(*sa_bis,sa_tmp,cpt);
(*sa_bis)[cpt] = '\0';
}
#endif
/*
Name : static goolean esp_sa_parse_filter(const gchar *sa, gint *pt_protocol_typ, gchar **pt_src, gint *pt_src_len, gchar **pt_dst, gint *pt_dst_len, gchar **pt_spi)
Description : Parse a Security Association.
Parse a Security Association and give the correspondings parameter : SPI, Source, Destination, Source Length, Destination Length, Protocol Type
There is no need to allocate memory before the call. All is done !
If the SA is not correct FALSE is returned.
This security association Must have the following format :
"Type/Source IPv6 or IPv4/Destination IPv6 or IPv4/SPI"
Where Type is either IPv4 either IPv6
- source And destination Must have a correct IPv6/IPv4 Address Format.
- SPI is an integer on 4 bytes.
Any element may use the following wildcard :
"*" : for an IPv4 Address, it allows all bytes until the next ".". For IPv6 it is the same until the next ":".
For SPI it allows any SPI.
ex:
a) IPV4/131.254.200.* /131.254.*.123/ *
b) IPv6/3ffe:*:1/2001::200:* / 456
Return : Return true if the parsing is correct.
Params:
- char *sa : the Security Association in char *
- gint *pt_protocol_typ : the protocol type
- gchar **pt_src : the source address
- gint *pt_src_len : the source address length
- gchar **pt_dst : the destination address
- gint *pt_dst_len : the destination address length
- gchar **pt_spi : the spi of the SA
*/
#ifdef __USE_LIBGCRYT__
static gboolean
esp_sa_parse_filter(const gchar *sa_src, gint *pt_protocol_typ, gchar **pt_src, gint *pt_src_len, gchar **pt_dst, gint *pt_dst_len, gchar **pt_spi)
{
gchar *src_string;
gchar *dst_string;
gchar *spi_string;
guint src_len = 0;
guint dst_len = 0;
gchar *src;
gchar *dst;
gchar *sa;
guint index_end1 = 0;
guint index_end2 = 0;
esp_sa_remove_white(sa_src,&sa);
if(!esp_sa_parse_protocol_typ(sa, 0, pt_protocol_typ, &index_end1)) return FALSE;
switch(*pt_protocol_typ)
{
case IPSEC_SA_IPV4 :
{
if(esp_sa_parse_ipv4addr(sa, index_end1, &src_string, &index_end2))
{
if(esp_sa_parse_addr_len(sa, index_end2, pt_src_len, &index_end1))
{
if(esp_sa_parse_ipv4addr(sa, index_end1, &dst_string, &index_end2))
{
if(esp_sa_parse_addr_len(sa, index_end2, pt_dst_len, &index_end1))
{
if(!esp_sa_parse_spi(sa, index_end1, &spi_string, &index_end2))
{
g_free(src_string);
g_free(dst_string);
g_free(spi_string);
g_free(sa);
return FALSE;
}
}
else
{
g_free(src_string);
g_free(dst_string);
g_free(sa);
return FALSE;
}
}
else
{
g_free(src_string);
g_free(sa);
return FALSE;
}
}
else
{
g_free(src_string);
g_free(sa);
return FALSE;
}
}
else
{
g_free(sa);
return FALSE;
}
/* Fill the Source Filter */
src = (gchar *)g_malloc((IPSEC_STRLEN_IPV4 + 1) * sizeof(gchar));
get_full_ipv4_addr(src, src_string);
g_free(src_string);
/* Fill the Destination Filter */
dst = (gchar *)g_malloc((IPSEC_STRLEN_IPV4 + 1) * sizeof(gchar));
get_full_ipv4_addr(dst, dst_string);
g_free(dst_string);
g_free(sa);
break;
}
case IPSEC_SA_IPV6 :
{
if(esp_sa_parse_ipv6addr(sa, index_end1, &src_string, &index_end2))
{
if(esp_sa_parse_addr_len(sa, index_end2, &src_len, &index_end1))
{
if(esp_sa_parse_ipv6addr(sa, index_end1, &dst_string, &index_end2))
{
if(esp_sa_parse_addr_len(sa, index_end2, &dst_len, &index_end1))
{
if(!esp_sa_parse_spi(sa, index_end1, &spi_string, &index_end2))
{
g_free(src_string);
g_free(dst_string);
g_free(spi_string);
g_free(sa);
return FALSE;
}
}
else
{
g_free(src_string);
g_free(dst_string);
g_free(sa);
return FALSE;
}
}
else
{
g_free(src_string);
g_free(sa);
return FALSE;
}
}
else
{
g_free(src_string);
g_free(sa);
return FALSE;
}
}
else
{
g_free(sa);
return FALSE;
}
/* Fill the Source Filter */
src = (gchar *)g_malloc((IPSEC_STRLEN_IPV6 + 1) * sizeof(gchar));
get_full_ipv6_addr(src, src_string);
g_free(src_string);
/* Fill the Destination Filter */
dst = (gchar *)g_malloc((IPSEC_STRLEN_IPV6 + 1) * sizeof(gchar));
get_full_ipv6_addr(dst, dst_string);
g_free(dst_string);
g_free(sa);
break;
}
default:
{
g_free(sa);
return FALSE;
}
}
*pt_spi = spi_string;
*pt_src = src;
*pt_dst = dst;
return TRUE;
}
#endif
/*
Name : static goolean filter_address_match(gchar *address, gchar *filter, gint len, gint typ)
Description : check the matching of an address with a filter
Return : Return TRUE if the filter and the address match
Params:
- gchar *address : the address to check
- gchar *filter : the filter
- gint len : the len of the address that should match the filter
- gint typ : the Address type : either IPv6 or IPv4 (IPSEC_SA_IPV6, IPSEC_SA_IPV4)
*/
#ifdef __USE_LIBGCRYT__
static gboolean
filter_address_match(gchar *address, gchar *filter, gint len, gint typ)
{
gint i = 0;
guint filter_tmp = 0;
guint addr_tmp = 0;
char filter_string_tmp[3];
char addr_string_tmp[3];
if(strlen(address) != strlen(filter)) return FALSE;
/* No length specified */
if((len < 0) || ((typ == IPSEC_SA_IPV6) && (len > IPSEC_IPV6_ADDR_LEN)) || ((typ == IPSEC_SA_IPV4) && (len > IPSEC_IPV4_ADDR_LEN)))
{
for(i = 0; (guint)i < strlen(address); i++)
{
if((filter[i] != IPSEC_SA_WILDCARDS_ANY) && (filter[i] != address[i])) return FALSE;
}
return TRUE;
}
else
{
for(i = 0; i < (len/ 4); i++)
{
if((filter[i] != IPSEC_SA_WILDCARDS_ANY) && (filter[i] != address[i])) return FALSE;
}
if(filter[i] == IPSEC_SA_WILDCARDS_ANY) return TRUE;
else if (len % 4 != 0)
{
/* take the end of the Netmask/Prefixlen into account */
filter_string_tmp[0] = filter[i];
filter_string_tmp[1] = '\0';
addr_string_tmp[0] = address[i];
addr_string_tmp[1] = '\0';
sscanf(filter_string_tmp,"%x",&filter_tmp);
sscanf(addr_string_tmp,"%x",&addr_tmp);
for(i = 0; i < (len % 4); i++)
{
if(((filter_tmp >> (4 -i -1)) & 1) != ((addr_tmp >> (4 -i -1)) & 1))
{
return FALSE;
}
}
}
}
return TRUE;
}
#endif
/*
Name : static goolean filter_spi_match(gchar *spi, gchar *filter)
Description : check the matching of a spi with a filter
Return : Return TRUE if the filter match the spi.
Params:
- gchar *spi : the spi to check
- gchar *filter : the filter
*/
#ifdef __USE_LIBGCRYT__
static gboolean
filter_spi_match(gchar *spi, gchar *filter)
{
guint i = 0;
if((strlen(filter) == 1) && (filter[0] == IPSEC_SA_WILDCARDS_ANY)) {
return TRUE;
}
else if(strlen(spi) != strlen(filter)) {
return FALSE;
}
for(i = 0; i < strlen(filter); i++)
{
if((filter[i] != IPSEC_SA_WILDCARDS_ANY) && (filter[i] != spi[i])) return FALSE;
}
return TRUE;
}
#endif
/*
Name : static goolean get_esp_sa(g_esp_sa_database *sad, gint protocol_typ, gchar *src, gchar *dst, gint spi,
gint *entry_index
gint *encryption_algo,
gint *authentication_algo,
gchar **encryption_key
Description : Give Encryption Algo, Key and Authentification Algo for a Packet if a corresponding SA is available in a Security Association database
Return: If the SA is not present, FALSE is then returned.
Params:
- g_esp_sa_database *sad : the Security Association Database
- gint *pt_protocol_typ : the protocol type
- gchar *src : the source address
- gchar *dst : the destination address
- gchar *spi : the spi of the SA
- gint *entry_index : the index of the SA that matches
- gint *encryption_algo : the Encryption Algorithm to apply the packet
- gint *authentication_algo : the Authentication Algorithm to apply to the packet
- gchar **encryption_key : the Encryption Key to apply the packet
*/
#ifdef __USE_LIBGCRYT__
static gboolean
get_esp_sa(g_esp_sa_database *sad, gint protocol_typ, gchar *src, gchar *dst, gint spi, gint *entry_index,
gint *encryption_algo,
gint *authentication_algo,
gchar **encryption_key
/************** UNCOMMENT THIS PART IF YOU WANT TO ADD CHECKING OF AUTHENTICATION *********************/
/*
,gchar **authentication_key
*/
/************** UNCOMMENT THIS PART IF YOU WANT TO ADD CHECKING OF AUTHENTICATION *********************/
)
{
gboolean found = FALSE;
gint i = 0;
guint spi_len_max = 10;
gchar spi_string[spi_len_max];
*entry_index = -1;
g_snprintf(spi_string, spi_len_max,"%i", spi);
while((found == FALSE) && (i < sad -> nb))
{
if(esp_sa_parse_filter(sad -> table[i].sa, &sad -> table[i].typ, &sad -> table[i].src, &sad -> table[i].src_len,
&sad -> table[i].dst, &sad -> table[i].dst_len, &sad -> table[i].spi))
{
g_esp_sad.table[i].is_valid = TRUE;
/* Debugging Purpose */
/*
fprintf(stderr, "VALID SA => <SA : %s> <Filter Source : %s/%i> <Filter Destination : %s/%i> <SPI : %s>\n", g_esp_sad.table[i].sa, g_esp_sad.table[i].src, g_esp_sad.table[i].src_len,
g_esp_sad.table[i].dst, g_esp_sad.table[i].dst_len, g_esp_sad.table[i].spi);
*/
if((protocol_typ == sad -> table[i].typ)
&& filter_address_match(src,sad -> table[i].src, sad -> table[i].src_len, protocol_typ)
&& filter_address_match(dst,sad -> table[i].dst, sad -> table[i].dst_len, protocol_typ)
&& filter_spi_match(spi_string, sad -> table[i].spi))
{
*entry_index = i;
*encryption_algo = sad -> table[i].encryption_algo;
*authentication_algo = sad -> table[i].authentication_algo;
/************** UNCOMMENT THIS PART IF YOU WANT TO ADD CHECKING OF AUTHENTICATION *********************/
/*
*authentication_key = (gchar *)sad -> table[i].authentication_key;
*/
/************** UNCOMMENT THIS PART IF YOU WANT TO ADD CHECKING OF AUTHENTICATION *********************/
*encryption_key = (gchar *)sad -> table[i].encryption_key;
found = TRUE;
/* Debugging Purpose */
/*
fprintf(stderr,"MATCHING SA => <IP Source : %s> <IP Destination : %s> <SPI : %s>\n\
=> <FILTER Source : %s/%i> <FILTER Destination : %s/%i> <FILTER SPI : %s>\n\
=> <Encryption Algo : %i> <Encryption Key: %s> <Authentication Algo : %i>\n",
src,dst,spi_string,
sad -> table[i].src, sad -> table[i].src_len,
sad -> table[i].dst, sad -> table[i].dst_len,
sad -> table[i].spi,
*encryption_algo, *encryption_key, *authentication_algo);
*/
}
/* We free the Src, Dst and Spi in the SA, but perhaps to allocate it again with the same value !!! */
g_free(g_esp_sad.table[i].src);
g_free(g_esp_sad.table[i].dst);
g_free(g_esp_sad.table[i].spi);
g_esp_sad.table[i].is_valid = FALSE;
}
else
{
/* Debugging Purpose */
/* fprintf(stderr, "INVALID SA => %s \n", g_esp_sad.table[i].sa); */
}
i++;
}
return found;
}
#endif
static void
dissect_ah(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_tree *next_tree;
guint8 nxt;
tvbuff_t *next_tvb;
int advance;
advance = dissect_ah_header(tvb, pinfo, tree, &nxt, &next_tree);
next_tvb = tvb_new_subset(tvb, advance, -1, -1);
if (g_ah_payload_in_subtree) {
col_set_writable(pinfo->cinfo, FALSE);
}
/* do lookup with the subdissector table */
if (!dissector_try_port(ip_dissector_table, nxt, next_tvb, pinfo, next_tree)) {
call_dissector(data_handle,next_tvb, pinfo, next_tree);
}
}
int
dissect_ah_header(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
guint8 *nxt_p, proto_tree **next_tree_p)
{
proto_tree *ah_tree;
proto_item *ti;
struct newah ah;
int advance;
if (check_col(pinfo->cinfo, COL_PROTOCOL))
col_set_str(pinfo->cinfo, COL_PROTOCOL, "AH");
if (check_col(pinfo->cinfo, COL_INFO))
col_clear(pinfo->cinfo, COL_INFO);
tvb_memcpy(tvb, (guint8 *)&ah, 0, sizeof(ah));
advance = sizeof(ah) + ((ah.ah_len - 1) << 2);
if (check_col(pinfo->cinfo, COL_INFO)) {
col_add_fstr(pinfo->cinfo, COL_INFO, "AH (SPI=0x%08x)",
(guint32)g_ntohl(ah.ah_spi));
}
if (tree) {
/* !!! specify length */
ti = proto_tree_add_item(tree, proto_ah, tvb, 0, advance, FALSE);
ah_tree = proto_item_add_subtree(ti, ett_ah);
proto_tree_add_text(ah_tree, tvb,
offsetof(struct newah, ah_nxt), 1,
"Next Header: %s (0x%02x)",
ipprotostr(ah.ah_nxt), ah.ah_nxt);
proto_tree_add_text(ah_tree, tvb,
offsetof(struct newah, ah_len), 1,
"Length: %u", (ah.ah_len + 2) << 2);
proto_tree_add_uint(ah_tree, hf_ah_spi, tvb,
offsetof(struct newah, ah_spi), 4,
(guint32)g_ntohl(ah.ah_spi));
proto_tree_add_uint(ah_tree, hf_ah_sequence, tvb,
offsetof(struct newah, ah_seq), 4,
(guint32)g_ntohl(ah.ah_seq));
proto_tree_add_text(ah_tree, tvb,
sizeof(ah), (ah.ah_len) ? (ah.ah_len - 1) << 2 : 0,
"IV");
if (next_tree_p != NULL) {
/* Decide where to place next protocol decode */
if (g_ah_payload_in_subtree) {
*next_tree_p = ah_tree;
}
else {
*next_tree_p = tree;
}
}
} else {
if (next_tree_p != NULL)
*next_tree_p = NULL;
}
if (nxt_p != NULL)
*nxt_p = ah.ah_nxt;
/* start of the new header (could be a extension header) */
return advance;
}
static void
dissect_esp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_tree *esp_tree;
proto_item *ti;
struct newesp esp;
gint len = 0;
gint i = 0;
#ifdef __USE_LIBGCRYT__
char res[3];
/* Packet Variables related */
gchar *ip_src = NULL;
gchar *ip_dst = NULL;
guint32 spi = 0;
#endif
guint encapsulated_protocol = 0;
gboolean auth_decode_ok = FALSE;
#ifdef __USE_LIBGCRYT__
gboolean get_address_ok = FALSE;
gboolean null_encryption_decode_heuristic = FALSE;
guint8 *decrypted_data = NULL;
guint8 *encrypted_data = NULL;
tvbuff_t *tvb_decrypted;
gint entry_index;
/* IPSEC encryption Variables related */
gint protocol_typ = IPSEC_SA_UNKNOWN;
gint esp_crypt_algo = IPSEC_ENCRYPT_NULL;
gint esp_auth_algo = IPSEC_AUTH_NULL;
gchar *esp_crypt_key;
gint esp_iv_len = 0;
gint esp_auth_len = 0;
gint decrypted_len = 0;
gboolean decrypt_ok = FALSE;
gboolean decrypt_using_libgcrypt = FALSE;
#endif
gint esp_pad_len = 0;
#ifdef __USE_LIBGCRYT__
/************** UNCOMMENT THIS PART IF YOU WANT TO ADD CHECKING OF AUTHENTICATION *********************/
/*
gchar *esp_auth_key;
*/
/************** UNCOMMENT THIS PART IF YOU WANT TO ADD CHECKING OF AUTHENTICATION *********************/
/* Variables for decryption used for libgrypt */
int decrypted_len_alloc = 0;
gcry_cipher_hd_t hd;
gcry_error_t err = 0;
int crypt_algo_libgcrypt = 0;
int crypt_mode_libgcrypt = 0;
/*
* load the top pane info. This should be overwritten by
* the next protocol in the stack
*/
#endif
if (check_col(pinfo->cinfo, COL_PROTOCOL))
col_set_str(pinfo->cinfo, COL_PROTOCOL, "ESP");
if (check_col(pinfo->cinfo, COL_INFO))
col_clear(pinfo->cinfo, COL_INFO);
tvb_memcpy(tvb, (guint8 *)&esp, 0, sizeof(esp));
if (check_col(pinfo->cinfo, COL_INFO)) {
col_add_fstr(pinfo->cinfo, COL_INFO, "ESP (SPI=0x%08x)",
(guint32)g_ntohl(esp.esp_spi));
}
/*
* populate a tree in the second pane with the status of the link layer
* (ie none)
*/
if(tree) {
len = 0, encapsulated_protocol = 0;
auth_decode_ok = FALSE;
i = 0;
ti = proto_tree_add_item(tree, proto_esp, tvb, 0, -1, FALSE);
esp_tree = proto_item_add_subtree(ti, ett_esp);
proto_tree_add_uint(esp_tree, hf_esp_spi, tvb,
offsetof(struct newesp, esp_spi), 4,
(guint32)g_ntohl(esp.esp_spi));
proto_tree_add_uint(esp_tree, hf_esp_sequence, tvb,
offsetof(struct newesp, esp_seq), 4,
(guint32)g_ntohl(esp.esp_seq));
#ifdef __USE_LIBGCRYT__
/* The SAD is not activated */
if(g_esp_enable_null_encryption_decode_heuristic && !g_esp_enable_encryption_decode) null_encryption_decode_heuristic = TRUE;
if(g_esp_enable_encryption_decode)
{
/* Get Dource & Destination Addresses in gchar * with all the bytes available. */
switch (pinfo -> src.type)
{
case AT_IPv4 :
{
ip_src = (gchar *) g_malloc((IPSEC_STRLEN_IPV4 + 1) * sizeof(gchar));
ip_dst = (gchar *) g_malloc((IPSEC_STRLEN_IPV4 + 1) * sizeof(gchar));
protocol_typ = IPSEC_SA_IPV4;
for(i = 0 ; i < pinfo -> src.len; i++)
{
if(((guint8 *)(pinfo -> src.data))[i] < 16)
{
g_snprintf(res,3,"0%X ", (pinfo -> src.data)[i]);
}
else
{
g_snprintf(res,3,"%X ", (pinfo -> src.data)[i]);
}
memcpy(ip_src + i*2, res, 2);
}
ip_src[IPSEC_STRLEN_IPV4] = '\0';
for(i = 0 ; i < pinfo -> dst.len; i++)
{
if(((guint8 *)(pinfo -> dst.data))[i] < 16)
{
g_snprintf(res,3,"0%X ", (pinfo -> dst.data)[i]);
}
else
{
g_snprintf(res,3,"%X ", (pinfo -> dst.data)[i]);
}
memcpy(ip_dst + i*2, res, 2);
}
ip_dst[IPSEC_STRLEN_IPV4] = '\0';
get_address_ok = TRUE;
break;
}
case AT_IPv6 :
{
ip_src = (gchar *) g_malloc((IPSEC_STRLEN_IPV6 + 1) * sizeof(gchar));
ip_dst = (gchar *) g_malloc((IPSEC_STRLEN_IPV6 + 1) * sizeof(gchar));
protocol_typ = IPSEC_SA_IPV6;
for(i = 0 ; i < pinfo -> src.len; i++)
{
if(((guint8 *)(pinfo -> src.data))[i] < 16)
{
g_snprintf(res,3,"0%X ", (pinfo -> src.data)[i]);
}
else
{
g_snprintf(res,3,"%X ", (pinfo -> src.data)[i]);
}
memcpy(ip_src + i*2, res, 2);
}
ip_src[IPSEC_STRLEN_IPV6] = '\0';
for(i = 0 ; i < pinfo -> dst.len; i++)
{
if(((guint8 *)(pinfo -> dst.data))[i] < 16)
{
g_snprintf(res,3,"0%X ", (pinfo -> dst.data)[i]);
}
else
{
g_snprintf(res,3,"%X ", (pinfo -> dst.data)[i]);
}
memcpy(ip_dst + i*2, res, 2);
}
ip_dst[IPSEC_STRLEN_IPV6] = '\0';
get_address_ok = TRUE;
break;
}
default :
{
get_address_ok = FALSE;
break;
}
}
/* The packet cannot be decoded using the SAD */
if(g_esp_enable_null_encryption_decode_heuristic && !get_address_ok) null_encryption_decode_heuristic = TRUE;
if(get_address_ok)
{
/* Get the SPI */
if(tvb_bytes_exist(tvb, 0, 4))
{
spi = tvb_get_ntohl(tvb, 0);
}
/*
PARSE the SAD and fill it. It may take some time since it will be called every times an ESP Payload is found.
It would have been better to do it in the proto registration, but because there is no way to add a crossbar, you have to do a parsing and have a SA Rule.
*/
if(get_esp_sa(&g_esp_sad, protocol_typ, ip_src, ip_dst, spi, &entry_index, &esp_crypt_algo, &esp_auth_algo, &esp_crypt_key
/************** UNCOMMENT THIS PART IF YOU WANT TO ADD CHECKING OF AUTHENTICATION *********************/
/*
, &esp_auth_key
*/
/************** UNCOMMENT THIS PART IF YOU WANT TO ADD CHECKING OF AUTHENTICATION *********************/
))
{
/* Desactivation of the Heuristic to decrypt using the NULL encryption algorithm since the packet is matching a SA */
null_encryption_decode_heuristic = FALSE;
/* Get length of whole ESP packet. */
len = tvb_reported_length(tvb);
switch(esp_auth_algo)
{
case IPSEC_AUTH_HMAC_SHA1_96:
{
esp_auth_len = 12;
break;
}
case IPSEC_AUTH_NULL:
{
esp_auth_len = 0;
break;
}
case IPSEC_AUTH_AES_XCBC_MAC_96:
{
esp_auth_len = 12;
break;
}
case IPSEC_AUTH_HMAC_MD5_96:
{
esp_auth_len = 12;
break;
}
}
switch(esp_crypt_algo)
{
case IPSEC_ENCRYPT_3DES_CBC :
{
/* RFC 2451 says :
3DES CBC uses a key of 192 bits.
The first 3DES key is taken from the first 64 bits, the second
from the next 64 bits, and the third from the last 64 bits.
Implementations MUST take into consideration the parity bits when
initially accepting a new set of keys. Each of the three keys is
really 56 bits in length with the extra 8 bits used for parity. */
/* Fix parameters for 3DES-CBC */
esp_iv_len = 8;
crypt_algo_libgcrypt = GCRY_CIPHER_3DES;
crypt_mode_libgcrypt = GCRY_CIPHER_MODE_CBC;
decrypted_len = len - sizeof(struct newesp);
if (decrypted_len <= 0) decrypt_ok = FALSE;
else
{
if(decrypted_len % esp_iv_len == 0)
decrypted_len_alloc = decrypted_len;
else decrypted_len_alloc = (decrypted_len / esp_iv_len) * esp_iv_len + esp_iv_len;
if (strlen(esp_crypt_key) != gcry_cipher_get_algo_keylen (crypt_algo_libgcrypt))
{
fprintf (stderr,"<ESP Preferences> Error in Encryption Algorithm 3DES-CBC : Bad Keylen (%i Bits)\n",strlen(esp_crypt_key) * 8);
decrypt_ok = FALSE;
}
else decrypt_using_libgcrypt = TRUE;
}
break;
}
case IPSEC_ENCRYPT_AES_CBC :
{
/* RFC 3602 says :
AES supports three key sizes: 128 bits, 192 bits, and 256 bits. The
default key size is 128 bits, and all implementations MUST support
this key size. Implementations MAY also support key sizes of 192
bits and 256 bits. */
/* Fix parameters for AES-CBC */
esp_iv_len = 16;
crypt_mode_libgcrypt = GCRY_CIPHER_MODE_CBC;
decrypted_len = len - sizeof(struct newesp);
if (decrypted_len <= 0) decrypt_ok = FALSE;
else
{
if(decrypted_len % esp_iv_len == 0)
decrypted_len_alloc = decrypted_len;
else decrypted_len_alloc = (decrypted_len / esp_iv_len) * esp_iv_len + esp_iv_len;
switch(strlen(esp_crypt_key) * 8)
{
case 128:
{
crypt_algo_libgcrypt = GCRY_CIPHER_AES128;
decrypt_using_libgcrypt = TRUE;
break;
}
case 192:
{
crypt_algo_libgcrypt = GCRY_CIPHER_AES192;
decrypt_using_libgcrypt = TRUE;
break;
}
case 256:
{
crypt_algo_libgcrypt = GCRY_CIPHER_AES256;
decrypt_using_libgcrypt = TRUE;
break;
}
default:
{
fprintf (stderr,"<ESP Preferences> Error in Encryption Algorithm AES-CBC : Bad Keylen (%i Bits)\n",strlen(esp_crypt_key) * 8);
decrypt_ok = FALSE;
}
}
}
break;
}
case IPSEC_ENCRYPT_DES_CBC :
{
/* RFC 2405 says :
DES-CBC is a symmetric secret key algorithm. The key size is 64-bits.
[It is commonly known as a 56-bit key as the key has 56 significant
bits; the least significant bit in every byte is the parity bit.] */
/* Fix parameters for DES-CBC */
esp_iv_len = 8;
crypt_algo_libgcrypt = GCRY_CIPHER_DES;
crypt_mode_libgcrypt = GCRY_CIPHER_MODE_CBC;
decrypted_len = len - sizeof(struct newesp);
if (decrypted_len <= 0) decrypt_ok = FALSE;
else
{
if(decrypted_len % esp_iv_len == 0)
decrypted_len_alloc = decrypted_len;
else decrypted_len_alloc = (decrypted_len / esp_iv_len) * esp_iv_len + esp_iv_len;
if (strlen(esp_crypt_key) != gcry_cipher_get_algo_keylen (crypt_algo_libgcrypt))
{
fprintf (stderr,"<ESP Preferences> Error in Encryption Algorithm DES-CBC : Bad Keylen (%i Bits)\n",strlen(esp_crypt_key) * 8);
decrypt_ok = FALSE;
}
else decrypt_using_libgcrypt = TRUE;
}
break;
}
case IPSEC_ENCRYPT_AES_CTR :
{
/* RFC 3686 says :
AES supports three key sizes: 128 bits, 192 bits, and 256 bits. The
default key size is 128 bits, and all implementations MUST support
this key size. Implementations MAY also support key sizes of 192
bits and 256 bits. The remaining 32 bits will be used as nonce. */
/* Fix parameters for AES-CTR */
esp_iv_len = 8;
crypt_mode_libgcrypt = GCRY_CIPHER_MODE_CTR;
decrypted_len = len - sizeof(struct newesp);
if (decrypted_len <= 0) decrypt_ok = FALSE;
else
{
if(decrypted_len % esp_iv_len == 0)
decrypted_len_alloc = decrypted_len;
else decrypted_len_alloc = (decrypted_len / esp_iv_len) * esp_iv_len + esp_iv_len;
switch(strlen(esp_crypt_key) * 8)
{
case 160:
{
crypt_algo_libgcrypt = GCRY_CIPHER_AES128;
decrypt_using_libgcrypt = TRUE;
break;
}
case 224:
{
crypt_algo_libgcrypt = GCRY_CIPHER_AES192;
decrypt_using_libgcrypt = TRUE;
break;
}
case 288:
{
crypt_algo_libgcrypt = GCRY_CIPHER_AES256;
decrypt_using_libgcrypt = TRUE;
break;
}
default:
{
fprintf (stderr,"<ESP Preferences> Error in Encryption Algorithm AES-CTR : Bad Keylen (%i Bits)\n",strlen(esp_crypt_key) * 8);
decrypt_ok = FALSE;
}
}
}
break;
}
case IPSEC_ENCRYPT_TWOFISH_CBC :
{
/* Twofish is a 128-bit block cipher developed by Counterpane Labs
that accepts a variable-length key up to 256 bits .
We will only accept key sizes of 128 and 256 bits.
*/
/* Fix parameters for TWOFISH-CBC */
esp_iv_len = 16;
crypt_mode_libgcrypt = GCRY_CIPHER_MODE_CBC;
decrypted_len = len - sizeof(struct newesp);
if (decrypted_len <= 0) decrypt_ok = FALSE;
else
{
if(decrypted_len % esp_iv_len == 0)
decrypted_len_alloc = decrypted_len;
else decrypted_len_alloc = (decrypted_len / esp_iv_len) * esp_iv_len + esp_iv_len;
switch(strlen(esp_crypt_key) * 8)
{
case 128:
{
crypt_algo_libgcrypt = GCRY_CIPHER_TWOFISH128;
decrypt_using_libgcrypt = TRUE;
break;
}
case 256:
{
crypt_algo_libgcrypt = GCRY_CIPHER_TWOFISH;
decrypt_using_libgcrypt = TRUE;
break;
}
default:
{
fprintf (stderr,"<ESP Preferences> Error in Encryption Algorithm TWOFISH-CBC : Bad Keylen (%i Bits)\n",strlen(esp_crypt_key) * 8);
decrypt_ok = FALSE;
}
}
}
break;
}
case IPSEC_ENCRYPT_BLOWFISH_CBC :
{
/* Bruce Schneier of Counterpane Systems developed the Blowfish block
cipher algorithm.
RFC 2451 shows that Blowfish uses key sizes from 40 to 448 bits. The Default size is 128 bits.
We will only accept key sizes of 128 bits, because libgrypt only accept this key size.
*/
/* Fix parameters for BLOWFISH-CBC */
esp_iv_len = 8;
crypt_algo_libgcrypt = GCRY_CIPHER_BLOWFISH;
crypt_mode_libgcrypt = GCRY_CIPHER_MODE_CBC;
decrypted_len = len - sizeof(struct newesp);
if (decrypted_len <= 0) decrypt_ok = FALSE;
else
{
if(decrypted_len % esp_iv_len == 0)
decrypted_len_alloc = decrypted_len;
else decrypted_len_alloc = (decrypted_len / esp_iv_len) * esp_iv_len + esp_iv_len;
if (strlen(esp_crypt_key) != gcry_cipher_get_algo_keylen (crypt_algo_libgcrypt))
{
fprintf (stderr,"<ESP Preferences> Error in Encryption Algorithm BLOWFISH-CBC : Bad Keylen (%i Bits)\n",strlen(esp_crypt_key) * 8);
decrypt_ok = FALSE;
}
else
decrypt_using_libgcrypt = TRUE;
}
break;
}
case IPSEC_ENCRYPT_NULL :
default :
{
/* Fix parameters */
esp_iv_len = 0;
decrypted_len = len - sizeof(struct newesp);
if (decrypted_len <= 0) decrypt_ok = FALSE;
else
{
/* Allocate Buffers for Encrypted and Decrypted data */
decrypted_data = (guint8 *) g_malloc ((decrypted_len + 1)* sizeof(guint8));
tvb_memcpy(tvb, decrypted_data , sizeof(struct newesp), decrypted_len);
decrypt_ok = TRUE;
}
break;
}
}
if(decrypt_using_libgcrypt)
{
/* Allocate Buffers for Encrypted and Decrypted data */
encrypted_data = (guint8 *) g_malloc ((decrypted_len_alloc) * sizeof(guint8));
memset(encrypted_data,0,decrypted_len_alloc);
decrypted_data = (guint8 *) g_malloc ((decrypted_len_alloc + esp_iv_len)* sizeof(guint8));
tvb_memcpy(tvb, encrypted_data , sizeof(struct newesp), decrypted_len);
err = gcry_cipher_open (&hd, crypt_algo_libgcrypt, crypt_mode_libgcrypt, 0);
if (err)
{
fprintf (stderr,"<IPsec/ESP Dissector> Error in Algorithm %s Mode %d, grcy_open_cipher failed: %s\n",
gcry_cipher_algo_name(crypt_algo_libgcrypt), crypt_mode_libgcrypt, gpg_strerror (err));
g_free(encrypted_data);
g_free(decrypted_data);
decrypt_ok = FALSE;
}
else
{
err = gcry_cipher_setkey (hd, esp_crypt_key, strlen(esp_crypt_key));
if (err)
{
fprintf (stderr,"<IPsec/ESP Dissector> Error in Algorithm %s Mode %d, gcry_cipher_setkey failed: %s\n",
gcry_cipher_algo_name(crypt_algo_libgcrypt), crypt_mode_libgcrypt, gpg_strerror (err));
gcry_cipher_close (hd);
g_free(encrypted_data);
g_free(decrypted_data);
decrypt_ok = FALSE;
}
else
{
err = gcry_cipher_decrypt (hd, decrypted_data, decrypted_len_alloc + esp_iv_len, encrypted_data, decrypted_len_alloc);
if (err)
{
fprintf (stderr,"<IPsec/ESP Dissector> Error in Algorithm %s, Mode %d, gcry_cipher_decrypt failed: %s\n",
gcry_cipher_algo_name(crypt_algo_libgcrypt), crypt_mode_libgcrypt, gpg_strerror (err));
gcry_cipher_close (hd);
g_free(encrypted_data);
g_free(decrypted_data);
decrypt_ok = FALSE;
}
else
{
gcry_cipher_close (hd);
g_free(encrypted_data);
decrypt_ok = TRUE;
}
}
}
}
if(decrypt_ok)
{
tvb_decrypted = tvb_new_real_data(decrypted_data, decrypted_len, decrypted_len);
tvb_set_child_real_data_tvbuff(tvb, tvb_decrypted);
add_new_data_source(pinfo,
tvb_decrypted,
"Decrypted Data");
/* Handler to free the Decrypted Data Buffer. */
tvb_set_free_cb(tvb_decrypted,g_free);
if(tvb_bytes_exist(tvb_decrypted, 0, esp_iv_len))
{
if(esp_iv_len > 0)
proto_tree_add_text(esp_tree, tvb_decrypted,
0, esp_iv_len,
"IV");
}
else proto_tree_add_text(esp_tree, tvb_decrypted,
0, -1,
"IV (truncated)");
/* Make sure the packet is not truncated before the fields
* we need to read to determine the encapsulated protocol */
if(tvb_bytes_exist(tvb_decrypted, decrypted_len - esp_auth_len - 2, 2))
{
esp_pad_len = tvb_get_guint8(tvb_decrypted, decrypted_len - esp_auth_len - 2);
if(decrypted_len - esp_auth_len - esp_pad_len - esp_iv_len - 2 >= esp_iv_len)
{
/* Get the encapsulated protocol */
encapsulated_protocol = tvb_get_guint8(tvb_decrypted, decrypted_len - esp_auth_len - 1);
if(dissector_try_port(ip_dissector_table,
encapsulated_protocol,
tvb_new_subset(tvb_decrypted, esp_iv_len,
decrypted_len - esp_auth_len - esp_pad_len - esp_iv_len - 2,
decrypted_len - esp_auth_len - esp_pad_len - esp_iv_len - 2),
pinfo,
esp_tree)) /*tree))*/
{
auth_decode_ok = TRUE;
}
}
}
if(auth_decode_ok)
{
if(esp_pad_len !=0)
{
proto_tree_add_text(esp_tree, tvb_decrypted, decrypted_len - esp_auth_len - 2 - esp_pad_len, esp_pad_len,"PAD");
}
proto_tree_add_uint(esp_tree, hf_esp_pad, tvb_decrypted,
decrypted_len - esp_auth_len - 2, 1,
esp_pad_len);
proto_tree_add_uint(esp_tree, hf_esp_protocol, tvb_decrypted,
decrypted_len - esp_auth_len - 1, 1,
encapsulated_protocol);
if(esp_auth_len == 0)
{
proto_tree_add_text(esp_tree, tvb_decrypted, decrypted_len, decrypted_len,
"NULL Authentication");
}
/* Make sure we have the auth trailer data */
else if(tvb_bytes_exist(tvb, decrypted_len - esp_auth_len, esp_auth_len))
{
proto_tree_add_text(esp_tree, tvb_decrypted, decrypted_len - esp_auth_len, esp_auth_len,
"Authentication Data");
}
else
{
/* Truncated so just display what we have */
proto_tree_add_text(esp_tree, tvb_decrypted, decrypted_len - esp_auth_len, esp_auth_len - (decrypted_len - tvb_length(tvb_decrypted)),
"Authentication Data (truncated)");
}
}
else
{
call_dissector(data_handle,
tvb_new_subset(tvb_decrypted, 0, -1, -1),
pinfo, esp_tree);
}
}
}
else
{
/* The packet does not belong to a security Association */
null_encryption_decode_heuristic = g_esp_enable_null_encryption_decode_heuristic;
}
g_free(ip_src);
g_free(ip_dst);
}
}
if(null_encryption_decode_heuristic)
{
#endif
if(g_esp_enable_null_encryption_decode_heuristic)
{
/* Get length of whole ESP packet. */
len = tvb_reported_length(tvb);
/* Make sure the packet is not truncated before the fields
* we need to read to determine the encapsulated protocol */
if(tvb_bytes_exist(tvb, len - 14, 2))
{
esp_pad_len = tvb_get_guint8(tvb, len - 14);
encapsulated_protocol = tvb_get_guint8(tvb, len - 13);
if(dissector_try_port(ip_dissector_table,
encapsulated_protocol,
tvb_new_subset(tvb,
sizeof(struct newesp),
-1,
len - sizeof(struct newesp) - 14 - esp_pad_len),
pinfo,
esp_tree))
{
auth_decode_ok = TRUE;
}
}
}
if(auth_decode_ok)
{
proto_tree_add_uint(esp_tree, hf_esp_pad, tvb,
len - 14, 1,
esp_pad_len);
proto_tree_add_uint(esp_tree, hf_esp_protocol, tvb,
len - 13, 1,
encapsulated_protocol);
/* Make sure we have the auth trailer data */
if(tvb_bytes_exist(tvb, len - 12, 12))
{
proto_tree_add_text(esp_tree, tvb, len - 12, 12,
"Authentication Data");
}
else
{
/* Truncated so just display what we have */
proto_tree_add_text(esp_tree, tvb, len - 12, 12 - (len - tvb_length(tvb)),
"Authentication Data (truncated)");
}
}
else
{
call_dissector(data_handle,
tvb_new_subset(tvb, sizeof(struct newesp), -1, -1),
pinfo, esp_tree);
}
}
#ifdef __USE_LIBGCRYT__
}
#endif
}
static void
dissect_ipcomp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_tree *ipcomp_tree;
proto_item *ti;
struct ipcomp ipcomp;
const char *p;
/*
* load the top pane info. This should be overwritten by
* the next protocol in the stack
*/
if (check_col(pinfo->cinfo, COL_PROTOCOL))
col_set_str(pinfo->cinfo, COL_PROTOCOL, "IPComp");
if (check_col(pinfo->cinfo, COL_INFO))
col_clear(pinfo->cinfo, COL_INFO);
tvb_memcpy(tvb, (guint8 *)&ipcomp, 0, sizeof(ipcomp));
if (check_col(pinfo->cinfo, COL_INFO)) {
p = match_strval(g_ntohs(ipcomp.comp_cpi), cpi2val);
if (p == NULL) {
col_add_fstr(pinfo->cinfo, COL_INFO, "IPComp (CPI=0x%04x)",
g_ntohs(ipcomp.comp_cpi));
} else
col_add_fstr(pinfo->cinfo, COL_INFO, "IPComp (CPI=%s)", p);
}
/*
* populate a tree in the second pane with the status of the link layer
* (ie none)
*/
if (tree) {
ti = proto_tree_add_item(tree, proto_ipcomp, tvb, 0, -1, FALSE);
ipcomp_tree = proto_item_add_subtree(ti, ett_ipcomp);
proto_tree_add_text(ipcomp_tree, tvb,
offsetof(struct ipcomp, comp_nxt), 1,
"Next Header: %s (0x%02x)",
ipprotostr(ipcomp.comp_nxt), ipcomp.comp_nxt);
proto_tree_add_uint(ipcomp_tree, hf_ipcomp_flags, tvb,
offsetof(struct ipcomp, comp_flags), 1,
ipcomp.comp_flags);
proto_tree_add_uint(ipcomp_tree, hf_ipcomp_cpi, tvb,
offsetof(struct ipcomp, comp_cpi), 2,
g_ntohs(ipcomp.comp_cpi));
call_dissector(data_handle,
tvb_new_subset(tvb, sizeof(struct ipcomp), -1, -1), pinfo,
ipcomp_tree);
}
}
void
proto_register_ipsec(void)
{
#ifdef __USE_LIBGCRYT__
guint i=0;
#endif
static hf_register_info hf_ah[] = {
{ &hf_ah_spi,
{ "SPI", "ah.spi", FT_UINT32, BASE_HEX, NULL, 0x0,
"", HFILL }},
{ &hf_ah_sequence,
{ "Sequence", "ah.sequence", FT_UINT32, BASE_DEC, NULL, 0x0,
"", HFILL }}
};
static hf_register_info hf_esp[] = {
{ &hf_esp_spi,
{ "SPI", "esp.spi", FT_UINT32, BASE_HEX, NULL, 0x0,
"", HFILL }},
{ &hf_esp_sequence,
{ "Sequence", "esp.sequence", FT_UINT32, BASE_DEC, NULL, 0x0,
"", HFILL }},
{ &hf_esp_pad,
{ "Pad Length", "esp.pad", FT_UINT8, BASE_DEC, NULL, 0x0,
"", HFILL }},
{ &hf_esp_protocol,
{ "Next Header", "esp.protocol", FT_UINT8, BASE_HEX, NULL, 0x0,
"", HFILL }}
};
static hf_register_info hf_ipcomp[] = {
{ &hf_ipcomp_flags,
{ "Flags", "ipcomp.flags", FT_UINT8, BASE_HEX, NULL, 0x0,
"", HFILL }},
{ &hf_ipcomp_cpi,
{ "CPI", "ipcomp.cpi", FT_UINT16, BASE_HEX,
VALS(cpi2val), 0x0, "", HFILL }},
};
static gint *ett[] = {
&ett_ah,
&ett_esp,
&ett_ipcomp,
};
module_t *ah_module;
module_t *esp_module;
proto_ah = proto_register_protocol("Authentication Header", "AH", "ah");
proto_register_field_array(proto_ah, hf_ah, array_length(hf_ah));
proto_esp = proto_register_protocol("Encapsulating Security Payload",
"ESP", "esp");
proto_register_field_array(proto_esp, hf_esp, array_length(hf_esp));
proto_ipcomp = proto_register_protocol("IP Payload Compression",
"IPComp", "ipcomp");
proto_register_field_array(proto_ipcomp, hf_ipcomp, array_length(hf_ipcomp));
proto_register_subtree_array(ett, array_length(ett));
/* Register a configuration option for placement of AH payload dissection */
ah_module = prefs_register_protocol(proto_ah, NULL);
prefs_register_bool_preference(ah_module, "place_ah_payload_in_subtree",
"Place AH payload in subtree",
"Whether the AH payload decode should be placed in a subtree",
&g_ah_payload_in_subtree);
#ifdef __USE_LIBGCRYT__
static enum_val_t esp_encryption_algo[] = {
{"null", "NULL", IPSEC_ENCRYPT_NULL},
{"3descbc", "TripleDES-CBC [RFC2451]", IPSEC_ENCRYPT_3DES_CBC},
{"aescbc", "AES-CBC [RFC3602]", IPSEC_ENCRYPT_AES_CBC},
{"aesctr", "AES-CTR [RFC3686]", IPSEC_ENCRYPT_AES_CTR},
{"descbc", "DES-CBC [RFC2405]", IPSEC_ENCRYPT_DES_CBC},
{"blowfishcbc","BLOWFISH-CBC [RFC2451]", IPSEC_ENCRYPT_BLOWFISH_CBC},
{"twofishcbc","TWOFISH-CBC", IPSEC_ENCRYPT_TWOFISH_CBC},
{NULL,NULL,0}
};
static enum_val_t esp_authentication_algo[] = {
{"null", "NULL", IPSEC_AUTH_NULL},
{"hmacsha196", "HMAC-SHA1-96 [RFC2404]", IPSEC_AUTH_HMAC_SHA1_96},
{"aesxcbcmac96", "AES-XCBC-MAC-96 [RFC3566]", IPSEC_AUTH_AES_XCBC_MAC_96},
{"hmacmd596", "HMAC-MD5-96 [RFC2403]", IPSEC_AUTH_HMAC_MD5_96},
{NULL,NULL,0}
};
#endif
esp_module = prefs_register_protocol(proto_esp, NULL);
#ifdef __USE_LIBGCRYT__
/* Register SA configuration options for ESP decryption */
g_esp_sad.nb = g_esp_nb_sa;
for(i = 0; i < g_esp_nb_sa; i++)
{
g_esp_sad.table[i].sa = NULL;
g_esp_sad.table[i].typ = IPSEC_SA_UNKNOWN;
g_esp_sad.table[i].src = NULL;
g_esp_sad.table[i].dst = NULL;
g_esp_sad.table[i].spi = NULL;
g_esp_sad.table[i].src_len = -1;
g_esp_sad.table[i].dst_len = -1;
g_esp_sad.table[i].encryption_algo = IPSEC_ENCRYPT_NULL;
g_esp_sad.table[i].authentication_algo = IPSEC_AUTH_NULL;
g_esp_sad.table[i].encryption_key = NULL;
/************** UNCOMMENT THIS PART IF YOU WANT TO ADD CHECKING OF AUTHENTICATION *********************/
/*
g_esp_sad.table[i].authentication_key = NULL;
*/
/************** UNCOMMENT THIS PART IF YOU WANT TO ADD CHECKING OF AUTHENTICATION *********************/
g_esp_sad.table[i].is_valid = FALSE;
}
#endif
prefs_register_bool_preference(esp_module, "enable_null_encryption_decode_heuristic",
"Attempt to detect/decode NULL encrypted ESP payloads",
"This is done only if the Decoding is not SET or the packet does not belong to a SA. Assumes a 12 byte auth (HMAC-SHA1-96/HMAC-MD5-96/AES-XCBC-MAC-96) and attempts decode based on the ethertype 13 bytes from packet end",
&g_esp_enable_null_encryption_decode_heuristic);
#ifdef __USE_LIBGCRYT__
prefs_register_bool_preference(esp_module, "enable_encryption_decode",
"Attempt to detect/decode encrypted ESP payloads",
"Attempt to decode based on the SAD described hereafter.",
&g_esp_enable_encryption_decode);
/* prefs_register_uint_preference(esp_module, "nb_sa",
"Number of Security Associations",
"Number of Security Associations in the SAD",
10, &g_esp_nb_sa); */
char *str_sa_num = (char *) g_malloc (g_max_esp_size_nb_sa + 1);
for (i = 0; i < g_esp_nb_sa; i++)
{
if (i >= g_max_esp_nb_sa)
{
break;
}
g_snprintf(str_sa_num, g_max_esp_size_nb_sa + 1, "%i", i + 1);
char *str_sa = (char *) g_malloc(3 + g_max_esp_size_nb_sa + 2);
g_snprintf(str_sa,3 + g_max_esp_size_nb_sa + 2,"%s%s","sa_",str_sa_num);
char *str_sa_comment = (char *) g_malloc(4 + g_max_esp_size_nb_sa + 2);
g_snprintf(str_sa_comment,4 + g_max_esp_size_nb_sa + 2,"%s%s","SA #",str_sa_num);
prefs_register_string_preference(esp_module, str_sa,
str_sa_comment,
"This field uses the following syntax : \"<Protocol|Source Address|Destination Adress|SPI\". <Protocol>: either IPv4, IPv6 (upper and/or lowercase letters). <SPI> : the Security Parameter Index of the Security Association. You may indicate it in decimal (ex: 123) or in hexadecimal (ex: 0x45). The special keywords '*' may be used to match any SPI.Nevertheless, if you use more than one '*', it will restrict the length of the SPI in decimal to as many '*' as indicated. For example '**' will match 23 but not 234. 234 will be match by '***'. No checking will be done on the SPI value. Thus you have to take into account that the SPI is 4 bytes length. <Addresses> : In this field we may have IPv6 or IPv4 address. Any address is a combination of an address or a prefix and a Prefixlen/Netmask separated by '/'. You may omit the Prefixlen/Netmask, assuming that the Adress is 128 bits length for IPv6 and 32 bits length for IPv4. The character '*' used at the Prefixlen/Netmask p
osition will be as if you had omit it. <IPv6 Addresses> : Any valid IPv6 address is accepted. ex: 3FFE::1/128, 3FFE:4:5:6666::/64, ::1/128, 3FFE:4::5 . If your address is incorrect and longer than 16 bytes, only the last 16 bytes will be taken into account. You also may use the special character '*' to indicate any 4 bits block. ie : 3ffe::45*6. If you use only one '*' in the Address field it will accept any IPv6 address. <IPv4 Addresses> : Any valid IPv4 address is accepted. ex : 190.0.0.1/24, 10.0.0.2 .You also may use the special character '*' to indicate any 8 bits block. ie : 190.*.*.3. If you use only one '*' in the Address field it will accept any IPv4 address. No checking of correct IPv4 address will be done. For example 456.345.567.890 will be accepted. Thus you have to take care about what you write. Nevertheless only 3 characters will be taken into account for one byte. Ex : 190.0.0.0184 will not be considered correct. (Instead a kind of LRU Mechanism will be used
and the address taken into account will be 190.0.0.418). Moreover only the four first values will be used (Ie 190.0.0.12.13 will be considered as 190.0.0.12)."
,
&g_esp_sad.table[i].sa);
char *str_encryption_algorithm = (char *) g_malloc(21 + g_max_esp_size_nb_sa + 2);
g_snprintf(str_encryption_algorithm,21 + g_max_esp_size_nb_sa + 2,"%s%s","encryption_algorithm_",str_sa_num);
char *str_encryption_algorithm_comment = (char *) g_malloc(22 + g_max_esp_size_nb_sa + 2);
g_snprintf(str_encryption_algorithm_comment,22 + g_max_esp_size_nb_sa + 2,"%s%s","Encryption Algorithm #",str_sa_num);
prefs_register_enum_preference(esp_module, str_encryption_algorithm,
str_encryption_algorithm_comment,
"According to RFC 4305 Encryption Algorithms Requirements are the following : NULL (MUST), TripleDES-CBC [RFC2451] (MUST-), AES-CBC [RFC3602] (SHOULD+), AES-CTR [RFC3686] (SHOULD), DES-CBC [RFC2405] (SHOULD NOT). It will also decrypt BLOWFISH-CBC [RFC2451] and TWOFISH-CBC",
&g_esp_sad.table[i].encryption_algo, esp_encryption_algo, FALSE);
char *str_authentication_algorithm = (char *) g_malloc(25 + g_max_esp_size_nb_sa + 2);
g_snprintf(str_authentication_algorithm,25 + g_max_esp_size_nb_sa + 2,"%s%s","authentication_algorithm_",str_sa_num);
char *str_authentication_algorithm_comment = (char *) g_malloc(26 + g_max_esp_size_nb_sa + 2);
g_snprintf(str_authentication_algorithm_comment,26 + g_max_esp_size_nb_sa + 2,"%s%s","Authentication Algorithm #",str_sa_num);
prefs_register_enum_preference(esp_module, str_authentication_algorithm,
str_authentication_algorithm_comment,
"According to RFC 4305 Authentication Algorithms Requirements are the following : HMAC-SHA1-96 [RFC2404] (MUST), NULL (MUST), AES-XCBC-MAC-96 [RFC3566] (SHOULD+), HMAC-MD5-96 [RFC2403] (MAY).",
&g_esp_sad.table[i].authentication_algo, esp_authentication_algo, FALSE);
char *str_encryption_key = (char *) g_malloc(15 + g_max_esp_size_nb_sa + 2);
g_snprintf(str_encryption_key,15 + g_max_esp_size_nb_sa + 2,"%s%s","encryption_key_",str_sa_num);
char *str_encryption_key_comment = (char *) g_malloc(16 + g_max_esp_size_nb_sa + 2);
g_snprintf(str_encryption_key_comment,16 + g_max_esp_size_nb_sa + 2,"%s%s","Encryption Key #",str_sa_num);
prefs_register_string_preference(esp_module, str_encryption_key,
str_encryption_key_comment,
"The key sizes supported are the following : [TripleDES-CBC] : 192 bits. [AES-CBC] : 128/192/256 bits. [AES-CTR] : 160/224/288 bits. The remaining 32 bits will be used as nonce. [DES-CBC] : 64 bits. [BLOWFISH-CBC] : 128 bits. [TWOFISH-CBC] : 128/256 bits",
&g_esp_sad.table[i].encryption_key);
/************** UNCOMMENT THIS PART IF YOU WANT TO ADD CHECKING OF AUTHENTICATION *********************/
/*
char *str_authentication_key = (char *) g_malloc(19 + g_max_esp_size_nb_sa + 2);
g_snprintf(str_authentication_key,19 + g_max_esp_size_nb_sa + 2,"%s%s","authentication_key_",str_sa_num);
char *str_authentication_key_comment = (char *)g_malloc(20 + g_max_esp_size_nb_sa + 2);
g_snprintf(str_authentication_key_comment,21 + g_max_esp_size_nb_sa + 2,"%s%s","Authentication Key #",str_sa_num);
prefs_register_string_preference(esp_module, str_authentication_key,
str_authentication_key_comment,
"Authentication Key"
,
&g_esp_sad.table[i].authentication_key);
*/
/************** UNCOMMENT THIS PART IF YOU WANT TO ADD CHECKING OF AUTHENTICATION *********************/
}
g_free(str_sa_num);
#endif
register_dissector("esp", dissect_esp, proto_esp);
register_dissector("ah", dissect_ah, proto_ah);
}
void
proto_reg_handoff_ipsec(void)
{
dissector_handle_t esp_handle, ah_handle, ipcomp_handle;
data_handle = find_dissector("data");
ah_handle = find_dissector("ah");
dissector_add("ip.proto", IP_PROTO_AH, ah_handle);
esp_handle = find_dissector("esp");
dissector_add("ip.proto", IP_PROTO_ESP, esp_handle);
ipcomp_handle = create_dissector_handle(dissect_ipcomp, proto_ipcomp);
dissector_add("ip.proto", IP_PROTO_IPCOMP, ipcomp_handle);
ip_dissector_table = find_dissector_table("ip.proto");
}
- References:
- RE: [Ethereal-dev] IPsec Dissector to decrypt ESP Payload
- From: Filonenko Alexander-AAF013
- RE: [Ethereal-dev] IPsec Dissector to decrypt ESP Payload
- From: Thomas Sillaber
- RE: [Ethereal-dev] IPsec Dissector to decrypt ESP Payload
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