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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.
 *
 * Format and print EAP packets.
 *
 */

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

#include <tcpdump-stdinc.h>

#include "interface.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 {
    unsigned char   version;
    unsigned char   type;
    unsigned char   length[2];
};

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 {
    unsigned char       code;
    unsigned char       id;
    unsigned char       length[2];
};

#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 2716 */
#define         EAP_TYPE_SIM            18              /* RFC 4186 */
#define         EAP_TYPE_TTLS           21              /* 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 2716 - 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,
          register const u_char *cp,
          u_int length _U_)
{
    const struct eap_frame_t *eap;
    const u_char *tptr;
    u_int tlen, type, subtype;
    int count=0, len;

    tptr = cp;
    tlen = length;
    eap = (const struct eap_frame_t *)cp;
    ND_TCHECK(*eap);

    /* in non-verbose mode just lets print the basic info */
    if (ndo->ndo_vflag < 1) {
        ND_PRINT((ndo, "%s (%u) v%u, len %u",
               tok2str(eap_frame_type_values, "unknown", eap->type),
               eap->type,
               eap->version,
               EXTRACT_16BITS(eap->length)));
        return;
    }

    ND_PRINT((ndo, "%s (%u) v%u, len %u",
           tok2str(eap_frame_type_values, "unknown", eap->type),
           eap->type,
           eap->version,
           EXTRACT_16BITS(eap->length)));

    tptr += sizeof(const struct eap_frame_t);
    tlen -= sizeof(const struct eap_frame_t);

    switch (eap->type) {
    case EAP_FRAME_TYPE_PACKET:
        type = *(tptr);
        len = EXTRACT_16BITS(tptr+2);
        ND_PRINT((ndo, ", %s (%u), id %u, len %u",
               tok2str(eap_code_values, "unknown", type),
               type,
               *(tptr+1),
               len));

        ND_TCHECK2(*tptr, len);

        if (type <= 2) { /* For EAP_REQUEST and EAP_RESPONSE only */
            subtype = *(tptr+4);
            ND_PRINT((ndo, "\n\t\t Type %s (%u)",
                   tok2str(eap_type_values, "unknown", *(tptr+4)),
                   *(tptr + 4)));

            switch (subtype) {
            case EAP_TYPE_IDENTITY:
                if (len - 5 > 0) {
                    ND_PRINT((ndo, ", Identity: "));
                    safeputs(ndo, tptr + 5, len - 5);
                }
                break;

            case EAP_TYPE_NOTIFICATION:
                if (len - 5 > 0) {
                    ND_PRINT((ndo, ", Notification: "));
                    safeputs(ndo, tptr + 5, len - 5);
                }
                break;

            case EAP_TYPE_NAK:
                count = 5;

                /*
                 * one or more octets indicating
                 * the desired authentication
                 * type one octet per type
                 */
                while (count < len) {
                    ND_PRINT((ndo, " %s (%u),",
                           tok2str(eap_type_values, "unknown", *(tptr+count)),
                           *(tptr + count)));
                    count++;
                }
                break;

            case EAP_TYPE_TTLS:
                ND_PRINT((ndo, " TTLSv%u",
                       EAP_TTLS_VERSION(*(tptr + 5)))); /* fall through */
            case EAP_TYPE_TLS:
                ND_PRINT((ndo, " flags [%s] 0x%02x,",
                       bittok2str(eap_tls_flags_values, "none", *(tptr+5)),
                       *(tptr + 5)));

                if (EAP_TLS_EXTRACT_BIT_L(*(tptr+5))) {
                    ND_PRINT((ndo, " len %u", EXTRACT_32BITS(tptr + 6)));
                }
                break;

            case EAP_TYPE_FAST:
                ND_PRINT((ndo, " FASTv%u",
                       EAP_TTLS_VERSION(*(tptr + 5))));
                ND_PRINT((ndo, " flags [%s] 0x%02x,",
                       bittok2str(eap_tls_flags_values, "none", *(tptr+5)),
                       *(tptr + 5)));

                if (EAP_TLS_EXTRACT_BIT_L(*(tptr+5))) {
                    ND_PRINT((ndo, " len %u", EXTRACT_32BITS(tptr + 6)));
                }

                /* FIXME - TLV attributes follow */
                break;

            case EAP_TYPE_AKA:
            case EAP_TYPE_SIM:
                ND_PRINT((ndo, " subtype [%s] 0x%02x,",
                       tok2str(eap_aka_subtype_values, "unknown", *(tptr+5)),
                       *(tptr + 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;
            }
        }
        break;

    case EAP_FRAME_TYPE_LOGOFF:
    case EAP_FRAME_TYPE_ENCAP_ASF_ALERT:
    default:
        break;
    }
    return;

 trunc:
    ND_PRINT((ndo, "\n\t[|EAP]"));
}

/*
 * Local Variables:
 * c-basic-offset: 4
 * End:
 */