1/*
2 * Copyright (c) 1995, 1996, 1997
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that: (1) source code distributions
7 * retain the above copyright notice and this paragraph in its entirety, (2)
8 * distributions including binary code include the above copyright notice and
9 * this paragraph in its entirety in the documentation or other materials
10 * provided with the distribution, and (3) all advertising materials mentioning
11 * features or use of this software display the following acknowledgement:
12 * ``This product includes software developed by the University of California,
13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14 * the University nor the names of its contributors may be used to endorse
15 * or promote products derived from this software without specific prior
16 * written permission.
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20 *
21 * Initial contribution from John Hawkinson (jhawk@mit.edu).
22 */
23
24#define NETDISSECT_REWORKED
25#ifdef HAVE_CONFIG_H
26#include "config.h"
27#endif
28
29#include <tcpdump-stdinc.h>
30
31#include "interface.h"
32#include "extract.h"
33
34static const char tstr[] = " [|kerberos]";
35
36static const u_char *c_print(netdissect_options *, register const u_char *, register const u_char *);
37static const u_char *krb4_print_hdr(netdissect_options *, const u_char *);
38static void krb4_print(netdissect_options *, const u_char *);
39
40#define AUTH_MSG_KDC_REQUEST			1<<1
41#define AUTH_MSG_KDC_REPLY			2<<1
42#define AUTH_MSG_APPL_REQUEST			3<<1
43#define AUTH_MSG_APPL_REQUEST_MUTUAL		4<<1
44#define AUTH_MSG_ERR_REPLY			5<<1
45#define AUTH_MSG_PRIVATE			6<<1
46#define AUTH_MSG_SAFE				7<<1
47#define AUTH_MSG_APPL_ERR			8<<1
48#define AUTH_MSG_DIE				63<<1
49
50#define KERB_ERR_OK				0
51#define KERB_ERR_NAME_EXP			1
52#define KERB_ERR_SERVICE_EXP			2
53#define KERB_ERR_AUTH_EXP			3
54#define KERB_ERR_PKT_VER			4
55#define KERB_ERR_NAME_MAST_KEY_VER		5
56#define KERB_ERR_SERV_MAST_KEY_VER		6
57#define KERB_ERR_BYTE_ORDER			7
58#define KERB_ERR_PRINCIPAL_UNKNOWN		8
59#define KERB_ERR_PRINCIPAL_NOT_UNIQUE		9
60#define KERB_ERR_NULL_KEY			10
61
62struct krb {
63	uint8_t pvno;		/* Protocol Version */
64	uint8_t type;		/* Type+B */
65};
66
67static const struct tok type2str[] = {
68	{ AUTH_MSG_KDC_REQUEST,		"KDC_REQUEST" },
69	{ AUTH_MSG_KDC_REPLY,		"KDC_REPLY" },
70	{ AUTH_MSG_APPL_REQUEST,	"APPL_REQUEST" },
71	{ AUTH_MSG_APPL_REQUEST_MUTUAL,	"APPL_REQUEST_MUTUAL" },
72	{ AUTH_MSG_ERR_REPLY,		"ERR_REPLY" },
73	{ AUTH_MSG_PRIVATE,		"PRIVATE" },
74	{ AUTH_MSG_SAFE,		"SAFE" },
75	{ AUTH_MSG_APPL_ERR,		"APPL_ERR" },
76	{ AUTH_MSG_DIE,			"DIE" },
77	{ 0,				NULL }
78};
79
80static const struct tok kerr2str[] = {
81	{ KERB_ERR_OK,			"OK" },
82	{ KERB_ERR_NAME_EXP,		"NAME_EXP" },
83	{ KERB_ERR_SERVICE_EXP,		"SERVICE_EXP" },
84	{ KERB_ERR_AUTH_EXP,		"AUTH_EXP" },
85	{ KERB_ERR_PKT_VER,		"PKT_VER" },
86	{ KERB_ERR_NAME_MAST_KEY_VER,	"NAME_MAST_KEY_VER" },
87	{ KERB_ERR_SERV_MAST_KEY_VER,	"SERV_MAST_KEY_VER" },
88	{ KERB_ERR_BYTE_ORDER,		"BYTE_ORDER" },
89	{ KERB_ERR_PRINCIPAL_UNKNOWN,	"PRINCIPAL_UNKNOWN" },
90	{ KERB_ERR_PRINCIPAL_NOT_UNIQUE,"PRINCIPAL_NOT_UNIQUE" },
91	{ KERB_ERR_NULL_KEY,		"NULL_KEY"},
92	{ 0,				NULL}
93};
94
95static const u_char *
96c_print(netdissect_options *ndo,
97        register const u_char *s, register const u_char *ep)
98{
99	register u_char c;
100	register int flag;
101
102	flag = 1;
103	while (s < ep) {
104		c = *s++;
105		if (c == '\0') {
106			flag = 0;
107			break;
108		}
109		if (!ND_ISASCII(c)) {
110			c = ND_TOASCII(c);
111			ND_PRINT((ndo, "M-"));
112		}
113		if (!ND_ISPRINT(c)) {
114			c ^= 0x40;	/* DEL to ?, others to alpha */
115			ND_PRINT((ndo, "^"));
116		}
117		ND_PRINT((ndo, "%c", c));
118	}
119	if (flag)
120		return NULL;
121	return (s);
122}
123
124static const u_char *
125krb4_print_hdr(netdissect_options *ndo,
126               const u_char *cp)
127{
128	cp += 2;
129
130#define PRINT		if ((cp = c_print(ndo, cp, ndo->ndo_snapend)) == NULL) goto trunc
131
132	PRINT;
133	ND_PRINT((ndo, "."));
134	PRINT;
135	ND_PRINT((ndo, "@"));
136	PRINT;
137	return (cp);
138
139trunc:
140	ND_PRINT((ndo, "%s", tstr));
141	return (NULL);
142
143#undef PRINT
144}
145
146static void
147krb4_print(netdissect_options *ndo,
148           const u_char *cp)
149{
150	register const struct krb *kp;
151	u_char type;
152	u_short len;
153
154#define PRINT		if ((cp = c_print(ndo, cp, ndo->ndo_snapend)) == NULL) goto trunc
155/*  True if struct krb is little endian */
156#define IS_LENDIAN(kp)	(((kp)->type & 0x01) != 0)
157#define KTOHSP(kp, cp)	(IS_LENDIAN(kp) ? EXTRACT_LE_16BITS(cp) : EXTRACT_16BITS(cp))
158
159	kp = (struct krb *)cp;
160
161	if ((&kp->type) >= ndo->ndo_snapend) {
162		ND_PRINT((ndo, "%s", tstr));
163		return;
164	}
165
166	type = kp->type & (0xFF << 1);
167
168	ND_PRINT((ndo, " %s %s: ",
169	    IS_LENDIAN(kp) ? "le" : "be", tok2str(type2str, NULL, type)));
170
171	switch (type) {
172
173	case AUTH_MSG_KDC_REQUEST:
174		if ((cp = krb4_print_hdr(ndo, cp)) == NULL)
175			return;
176		cp += 4;	/* ctime */
177		ND_TCHECK(*cp);
178		ND_PRINT((ndo, " %dmin ", *cp++ * 5));
179		PRINT;
180		ND_PRINT((ndo, "."));
181		PRINT;
182		break;
183
184	case AUTH_MSG_APPL_REQUEST:
185		cp += 2;
186		ND_TCHECK(*cp);
187		ND_PRINT((ndo, "v%d ", *cp++));
188		PRINT;
189		ND_TCHECK(*cp);
190		ND_PRINT((ndo, " (%d)", *cp++));
191		ND_TCHECK(*cp);
192		ND_PRINT((ndo, " (%d)", *cp));
193		break;
194
195	case AUTH_MSG_KDC_REPLY:
196		if ((cp = krb4_print_hdr(ndo, cp)) == NULL)
197			return;
198		cp += 10;	/* timestamp + n + exp + kvno */
199		ND_TCHECK2(*cp, sizeof(short));
200		len = KTOHSP(kp, cp);
201		ND_PRINT((ndo, " (%d)", len));
202		break;
203
204	case AUTH_MSG_ERR_REPLY:
205		if ((cp = krb4_print_hdr(ndo, cp)) == NULL)
206			return;
207		cp += 4; 	  /* timestamp */
208		ND_TCHECK2(*cp, sizeof(short));
209		ND_PRINT((ndo, " %s ", tok2str(kerr2str, NULL, KTOHSP(kp, cp))));
210		cp += 4;
211		PRINT;
212		break;
213
214	default:
215		ND_PRINT((ndo, "(unknown)"));
216		break;
217	}
218
219	return;
220trunc:
221	ND_PRINT((ndo, "%s", tstr));
222}
223
224void
225krb_print(netdissect_options *ndo,
226          const u_char *dat)
227{
228	register const struct krb *kp;
229
230	kp = (struct krb *)dat;
231
232	if (dat >= ndo->ndo_snapend) {
233		ND_PRINT((ndo, "%s", tstr));
234		return;
235	}
236
237	switch (kp->pvno) {
238
239	case 1:
240	case 2:
241	case 3:
242		ND_PRINT((ndo, " v%d", kp->pvno));
243		break;
244
245	case 4:
246		ND_PRINT((ndo, " v%d", kp->pvno));
247		krb4_print(ndo, (const u_char *)kp);
248		break;
249
250	case 106:
251	case 107:
252		ND_PRINT((ndo, " v5"));
253		/* Decode ASN.1 here "someday" */
254		break;
255	}
256	return;
257}
258