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/*
* Copyright (c) 2004 - Michael Richardson <mcr@xelerance.com>
*
* 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.
*/
/* \summary: Extensible Authentication Protocol (EAP) printer */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "netdissect-stdinc.h"
#include "netdissect.h"
#include "extract.h"
#define EAP_FRAME_TYPE_PACKET 0
#define EAP_FRAME_TYPE_START 1
#define EAP_FRAME_TYPE_LOGOFF 2
#define EAP_FRAME_TYPE_KEY 3
#define EAP_FRAME_TYPE_ENCAP_ASF_ALERT 4
struct eap_frame_t {
nd_uint8_t version;
nd_uint8_t type;
nd_uint16_t length;
};
static const struct tok eap_frame_type_values[] = {
{ EAP_FRAME_TYPE_PACKET, "EAP packet" },
{ EAP_FRAME_TYPE_START, "EAPOL start" },
{ EAP_FRAME_TYPE_LOGOFF, "EAPOL logoff" },
{ EAP_FRAME_TYPE_KEY, "EAPOL key" },
{ EAP_FRAME_TYPE_ENCAP_ASF_ALERT, "Encapsulated ASF alert" },
{ 0, NULL}
};
/* RFC 3748 */
struct eap_packet_t {
nd_uint8_t code;
nd_uint8_t id;
nd_uint16_t length;
};
#define EAP_REQUEST 1
#define EAP_RESPONSE 2
#define EAP_SUCCESS 3
#define EAP_FAILURE 4
static const struct tok eap_code_values[] = {
{ EAP_REQUEST, "Request" },
{ EAP_RESPONSE, "Response" },
{ EAP_SUCCESS, "Success" },
{ EAP_FAILURE, "Failure" },
{ 0, NULL}
};
#define EAP_TYPE_NO_PROPOSED 0
#define EAP_TYPE_IDENTITY 1
#define EAP_TYPE_NOTIFICATION 2
#define EAP_TYPE_NAK 3
#define EAP_TYPE_MD5_CHALLENGE 4
#define EAP_TYPE_OTP 5
#define EAP_TYPE_GTC 6
#define EAP_TYPE_TLS 13 /* RFC 5216 */
#define EAP_TYPE_SIM 18 /* RFC 4186 */
#define EAP_TYPE_TTLS 21 /* RFC 5281, draft-funk-eap-ttls-v0-01.txt */
#define EAP_TYPE_AKA 23 /* RFC 4187 */
#define EAP_TYPE_FAST 43 /* RFC 4851 */
#define EAP_TYPE_EXPANDED_TYPES 254
#define EAP_TYPE_EXPERIMENTAL 255
static const struct tok eap_type_values[] = {
{ EAP_TYPE_NO_PROPOSED, "No proposed" },
{ EAP_TYPE_IDENTITY, "Identity" },
{ EAP_TYPE_NOTIFICATION, "Notification" },
{ EAP_TYPE_NAK, "Nak" },
{ EAP_TYPE_MD5_CHALLENGE, "MD5-challenge" },
{ EAP_TYPE_OTP, "OTP" },
{ EAP_TYPE_GTC, "GTC" },
{ EAP_TYPE_TLS, "TLS" },
{ EAP_TYPE_SIM, "SIM" },
{ EAP_TYPE_TTLS, "TTLS" },
{ EAP_TYPE_AKA, "AKA" },
{ EAP_TYPE_FAST, "FAST" },
{ EAP_TYPE_EXPANDED_TYPES, "Expanded types" },
{ EAP_TYPE_EXPERIMENTAL, "Experimental" },
{ 0, NULL}
};
#define EAP_TLS_EXTRACT_BIT_L(x) (((x)&0x80)>>7)
/* RFC 5216 - EAP TLS bits */
#define EAP_TLS_FLAGS_LEN_INCLUDED (1 << 7)
#define EAP_TLS_FLAGS_MORE_FRAGMENTS (1 << 6)
#define EAP_TLS_FLAGS_START (1 << 5)
static const struct tok eap_tls_flags_values[] = {
{ EAP_TLS_FLAGS_LEN_INCLUDED, "L bit" },
{ EAP_TLS_FLAGS_MORE_FRAGMENTS, "More fragments bit"},
{ EAP_TLS_FLAGS_START, "Start bit"},
{ 0, NULL}
};
#define EAP_TTLS_VERSION(x) ((x)&0x07)
/* EAP-AKA and EAP-SIM - RFC 4187 */
#define EAP_AKA_CHALLENGE 1
#define EAP_AKA_AUTH_REJECT 2
#define EAP_AKA_SYNC_FAILURE 4
#define EAP_AKA_IDENTITY 5
#define EAP_SIM_START 10
#define EAP_SIM_CHALLENGE 11
#define EAP_AKA_NOTIFICATION 12
#define EAP_AKA_REAUTH 13
#define EAP_AKA_CLIENT_ERROR 14
static const struct tok eap_aka_subtype_values[] = {
{ EAP_AKA_CHALLENGE, "Challenge" },
{ EAP_AKA_AUTH_REJECT, "Auth reject" },
{ EAP_AKA_SYNC_FAILURE, "Sync failure" },
{ EAP_AKA_IDENTITY, "Identity" },
{ EAP_SIM_START, "Start" },
{ EAP_SIM_CHALLENGE, "Challenge" },
{ EAP_AKA_NOTIFICATION, "Notification" },
{ EAP_AKA_REAUTH, "Reauth" },
{ EAP_AKA_CLIENT_ERROR, "Client error" },
{ 0, NULL}
};
/*
* Print EAP requests / responses
*/
void
eap_print(netdissect_options *ndo,
const u_char *cp,
u_int length)
{
u_int type, subtype, len;
u_int count;
const char *sep;
type = GET_U_1(cp);
len = GET_BE_U_2(cp + 2);
if (len != length) {
/*
* Probably a fragment; in some cases the fragmentation might
* not put an EAP header on every packet, if reassembly can
* be done without that (e.g., fragmentation to make a message
* fit in multiple TLVs in a RADIUS packet).
*/
ND_PRINT("EAP fragment?");
return;
}
ND_PRINT("%s (%u), id %u, len %u",
tok2str(eap_code_values, "unknown", type),
type,
GET_U_1((cp + 1)),
len);
if (len < 4) {
ND_PRINT(" (too short for EAP header)");
return;
}
ND_TCHECK_LEN(cp, len);
if (type == EAP_REQUEST || type == EAP_RESPONSE) {
/* RFC 3748 Section 4.1 */
if (len < 5) {
ND_PRINT(" (too short for EAP request/response)");
return;
}
subtype = GET_U_1(cp + 4);
ND_PRINT("\n\t\t Type %s (%u)",
tok2str(eap_type_values, "unknown", subtype),
subtype);
switch (subtype) {
case EAP_TYPE_IDENTITY:
/* According to RFC 3748, the message is optional */
if (len > 5) {
ND_PRINT(", Identity: ");
nd_printjnp(ndo, cp + 5, len - 5);
}
break;
case EAP_TYPE_NOTIFICATION:
/* According to RFC 3748, there must be at least one octet of message */
if (len < 6) {
ND_PRINT(" (too short for EAP Notification request/response)");
return;
}
ND_PRINT(", Notification: ");
nd_printjnp(ndo, cp + 5, len - 5);
break;
case EAP_TYPE_NAK:
/*
* one or more octets indicating
* the desired authentication
* type one octet per type
*/
if (len < 6) {
ND_PRINT(" (too short for EAP Legacy NAK request/response)");
return;
}
sep = "";
for (count = 5; count < len; count++) {
ND_PRINT("%s %s (%u)", sep,
tok2str(eap_type_values, "unknown", GET_U_1((cp + count))),
GET_U_1(cp + count));
sep = ",";
}
break;
case EAP_TYPE_TTLS:
case EAP_TYPE_TLS:
if (len < 6) {
ND_PRINT(" (too short for EAP TLS/TTLS request/response)");
return;
}
if (subtype == EAP_TYPE_TTLS)
ND_PRINT(" TTLSv%u",
EAP_TTLS_VERSION(GET_U_1((cp + 5))));
ND_PRINT(" flags [%s] 0x%02x",
bittok2str(eap_tls_flags_values, "none", GET_U_1((cp + 5))),
GET_U_1(cp + 5));
if (EAP_TLS_EXTRACT_BIT_L(GET_U_1(cp + 5))) {
if (len < 10) {
ND_PRINT(" (too short for EAP TLS/TTLS request/response with length)");
return;
}
ND_PRINT(", len %u", GET_BE_U_4(cp + 6));
}
break;
case EAP_TYPE_FAST:
if (len < 6) {
ND_PRINT(" (too short for EAP FAST request/response)");
return;
}
ND_PRINT(" FASTv%u",
EAP_TTLS_VERSION(GET_U_1((cp + 5))));
ND_PRINT(" flags [%s] 0x%02x",
bittok2str(eap_tls_flags_values, "none", GET_U_1((cp + 5))),
GET_U_1(cp + 5));
if (EAP_TLS_EXTRACT_BIT_L(GET_U_1(cp + 5))) {
if (len < 10) {
ND_PRINT(" (too short for EAP FAST request/response with length)");
return;
}
ND_PRINT(", len %u", GET_BE_U_4(cp + 6));
}
/* FIXME - TLV attributes follow */
break;
case EAP_TYPE_AKA:
case EAP_TYPE_SIM:
if (len < 6) {
ND_PRINT(" (too short for EAP SIM/AKA request/response)");
return;
}
ND_PRINT(" subtype [%s] 0x%02x",
tok2str(eap_aka_subtype_values, "unknown", GET_U_1((cp + 5))),
GET_U_1(cp + 5));
/* FIXME - TLV attributes follow */
break;
case EAP_TYPE_MD5_CHALLENGE:
case EAP_TYPE_OTP:
case EAP_TYPE_GTC:
case EAP_TYPE_EXPANDED_TYPES:
case EAP_TYPE_EXPERIMENTAL:
default:
break;
}
}
return;
trunc:
nd_print_trunc(ndo);
}
void
eapol_print(netdissect_options *ndo,
const u_char *cp)
{
const struct eap_frame_t *eap;
u_int eap_type, eap_len;
ndo->ndo_protocol = "eap";
eap = (const struct eap_frame_t *)cp;
ND_TCHECK_SIZE(eap);
eap_type = GET_U_1(eap->type);
ND_PRINT("%s (%u) v%u, len %u",
tok2str(eap_frame_type_values, "unknown", eap_type),
eap_type,
GET_U_1(eap->version),
GET_BE_U_2(eap->length));
if (ndo->ndo_vflag < 1)
return;
cp += sizeof(struct eap_frame_t);
eap_len = GET_BE_U_2(eap->length);
switch (eap_type) {
case EAP_FRAME_TYPE_PACKET:
if (eap_len == 0)
goto trunc;
ND_PRINT(", ");
eap_print(ndo, cp, eap_len);
return;
case EAP_FRAME_TYPE_LOGOFF:
case EAP_FRAME_TYPE_ENCAP_ASF_ALERT:
default:
break;
}
return;
trunc:
nd_print_trunc(ndo);
}
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