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 #ifndef lint
25 static const char rcsid[] _U_ =
26     "@(#) $Header: /tcpdump/master/tcpdump/print-krb.c,v 1.23 2003-11-16 09:36:26 guy Exp $";
27 #endif
28 
29 #ifdef HAVE_CONFIG_H
30 #include "config.h"
31 #endif
32 
33 #include <tcpdump-stdinc.h>
34 
35 #include <stdio.h>
36 
37 #include "interface.h"
38 #include "addrtoname.h"
39 #include "extract.h"
40 
41 static const u_char *c_print(register const u_char *, register const u_char *);
42 static const u_char *krb4_print_hdr(const u_char *);
43 static void krb4_print(const u_char *);
44 
45 #define AUTH_MSG_KDC_REQUEST			1<<1
46 #define AUTH_MSG_KDC_REPLY			2<<1
47 #define AUTH_MSG_APPL_REQUEST			3<<1
48 #define AUTH_MSG_APPL_REQUEST_MUTUAL		4<<1
49 #define AUTH_MSG_ERR_REPLY			5<<1
50 #define AUTH_MSG_PRIVATE			6<<1
51 #define AUTH_MSG_SAFE				7<<1
52 #define AUTH_MSG_APPL_ERR			8<<1
53 #define AUTH_MSG_DIE				63<<1
54 
55 #define KERB_ERR_OK				0
56 #define KERB_ERR_NAME_EXP			1
57 #define KERB_ERR_SERVICE_EXP			2
58 #define KERB_ERR_AUTH_EXP			3
59 #define KERB_ERR_PKT_VER			4
60 #define KERB_ERR_NAME_MAST_KEY_VER		5
61 #define KERB_ERR_SERV_MAST_KEY_VER		6
62 #define KERB_ERR_BYTE_ORDER			7
63 #define KERB_ERR_PRINCIPAL_UNKNOWN		8
64 #define KERB_ERR_PRINCIPAL_NOT_UNIQUE		9
65 #define KERB_ERR_NULL_KEY			10
66 
67 struct krb {
68 	u_int8_t pvno;		/* Protocol Version */
69 	u_int8_t type;		/* Type+B */
70 };
71 
72 static char tstr[] = " [|kerberos]";
73 
74 static const struct tok type2str[] = {
75 	{ AUTH_MSG_KDC_REQUEST,		"KDC_REQUEST" },
76 	{ AUTH_MSG_KDC_REPLY,		"KDC_REPLY" },
77 	{ AUTH_MSG_APPL_REQUEST,	"APPL_REQUEST" },
78 	{ AUTH_MSG_APPL_REQUEST_MUTUAL,	"APPL_REQUEST_MUTUAL" },
79 	{ AUTH_MSG_ERR_REPLY,		"ERR_REPLY" },
80 	{ AUTH_MSG_PRIVATE,		"PRIVATE" },
81 	{ AUTH_MSG_SAFE,		"SAFE" },
82 	{ AUTH_MSG_APPL_ERR,		"APPL_ERR" },
83 	{ AUTH_MSG_DIE,			"DIE" },
84 	{ 0,				NULL }
85 };
86 
87 static const struct tok kerr2str[] = {
88 	{ KERB_ERR_OK,			"OK" },
89 	{ KERB_ERR_NAME_EXP,		"NAME_EXP" },
90 	{ KERB_ERR_SERVICE_EXP,		"SERVICE_EXP" },
91 	{ KERB_ERR_AUTH_EXP,		"AUTH_EXP" },
92 	{ KERB_ERR_PKT_VER,		"PKT_VER" },
93 	{ KERB_ERR_NAME_MAST_KEY_VER,	"NAME_MAST_KEY_VER" },
94 	{ KERB_ERR_SERV_MAST_KEY_VER,	"SERV_MAST_KEY_VER" },
95 	{ KERB_ERR_BYTE_ORDER,		"BYTE_ORDER" },
96 	{ KERB_ERR_PRINCIPAL_UNKNOWN,	"PRINCIPAL_UNKNOWN" },
97 	{ KERB_ERR_PRINCIPAL_NOT_UNIQUE,"PRINCIPAL_NOT_UNIQUE" },
98 	{ KERB_ERR_NULL_KEY,		"NULL_KEY"},
99 	{ 0,				NULL}
100 };
101 
102 static const u_char *
c_print(register const u_char * s,register const u_char * ep)103 c_print(register const u_char *s, register const u_char *ep)
104 {
105 	register u_char c;
106 	register int flag;
107 
108 	flag = 1;
109 	while (s < ep) {
110 		c = *s++;
111 		if (c == '\0') {
112 			flag = 0;
113 			break;
114 		}
115 		if (!ND_ISASCII(c)) {
116 			c = ND_TOASCII(c);
117 			putchar('M');
118 			putchar('-');
119 		}
120 		if (!ND_ISPRINT(c)) {
121 			c ^= 0x40;	/* DEL to ?, others to alpha */
122 			putchar('^');
123 		}
124 		putchar(c);
125 	}
126 	if (flag)
127 		return NULL;
128 	return (s);
129 }
130 
131 static const u_char *
krb4_print_hdr(const u_char * cp)132 krb4_print_hdr(const u_char *cp)
133 {
134 	cp += 2;
135 
136 #define PRINT		if ((cp = c_print(cp, snapend)) == NULL) goto trunc
137 
138 	PRINT;
139 	putchar('.');
140 	PRINT;
141 	putchar('@');
142 	PRINT;
143 	return (cp);
144 
145 trunc:
146 	fputs(tstr, stdout);
147 	return (NULL);
148 
149 #undef PRINT
150 }
151 
152 static void
krb4_print(const u_char * cp)153 krb4_print(const u_char *cp)
154 {
155 	register const struct krb *kp;
156 	u_char type;
157 	u_short len;
158 
159 #define PRINT		if ((cp = c_print(cp, snapend)) == NULL) goto trunc
160 /*  True if struct krb is little endian */
161 #define IS_LENDIAN(kp)	(((kp)->type & 0x01) != 0)
162 #define KTOHSP(kp, cp)	(IS_LENDIAN(kp) ? EXTRACT_LE_16BITS(cp) : EXTRACT_16BITS(cp))
163 
164 	kp = (struct krb *)cp;
165 
166 	if ((&kp->type) >= snapend) {
167 		fputs(tstr, stdout);
168 		return;
169 	}
170 
171 	type = kp->type & (0xFF << 1);
172 
173 	printf(" %s %s: ",
174 	    IS_LENDIAN(kp) ? "le" : "be", tok2str(type2str, NULL, type));
175 
176 	switch (type) {
177 
178 	case AUTH_MSG_KDC_REQUEST:
179 		if ((cp = krb4_print_hdr(cp)) == NULL)
180 			return;
181 		cp += 4;	/* ctime */
182 		TCHECK(*cp);
183 		printf(" %dmin ", *cp++ * 5);
184 		PRINT;
185 		putchar('.');
186 		PRINT;
187 		break;
188 
189 	case AUTH_MSG_APPL_REQUEST:
190 		cp += 2;
191 		TCHECK(*cp);
192 		printf("v%d ", *cp++);
193 		PRINT;
194 		TCHECK(*cp);
195 		printf(" (%d)", *cp++);
196 		TCHECK(*cp);
197 		printf(" (%d)", *cp);
198 		break;
199 
200 	case AUTH_MSG_KDC_REPLY:
201 		if ((cp = krb4_print_hdr(cp)) == NULL)
202 			return;
203 		cp += 10;	/* timestamp + n + exp + kvno */
204 		TCHECK2(*cp, sizeof(short));
205 		len = KTOHSP(kp, cp);
206 		printf(" (%d)", len);
207 		break;
208 
209 	case AUTH_MSG_ERR_REPLY:
210 		if ((cp = krb4_print_hdr(cp)) == NULL)
211 			return;
212 		cp += 4; 	  /* timestamp */
213 		TCHECK2(*cp, sizeof(short));
214 		printf(" %s ", tok2str(kerr2str, NULL, KTOHSP(kp, cp)));
215 		cp += 4;
216 		PRINT;
217 		break;
218 
219 	default:
220 		fputs("(unknown)", stdout);
221 		break;
222 	}
223 
224 	return;
225 trunc:
226 	fputs(tstr, stdout);
227 }
228 
229 void
krb_print(const u_char * dat)230 krb_print(const u_char *dat)
231 {
232 	register const struct krb *kp;
233 
234 	kp = (struct krb *)dat;
235 
236 	if (dat >= snapend) {
237 		fputs(tstr, stdout);
238 		return;
239 	}
240 
241 	switch (kp->pvno) {
242 
243 	case 1:
244 	case 2:
245 	case 3:
246 		printf(" v%d", kp->pvno);
247 		break;
248 
249 	case 4:
250 		printf(" v%d", kp->pvno);
251 		krb4_print((const u_char *)kp);
252 		break;
253 
254 	case 106:
255 	case 107:
256 		fputs(" v5", stdout);
257 		/* Decode ASN.1 here "someday" */
258 		break;
259 	}
260 	return;
261 }
262