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
34 static const char tstr[] = " [|kerberos]";
35
36 static const u_char *c_print(netdissect_options *, register const u_char *, register const u_char *);
37 static const u_char *krb4_print_hdr(netdissect_options *, const u_char *);
38 static 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
62 struct krb {
63 uint8_t pvno; /* Protocol Version */
64 uint8_t type; /* Type+B */
65 };
66
67 static 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
80 static 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
95 static const u_char *
c_print(netdissect_options * ndo,register const u_char * s,register const u_char * ep)96 c_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
124 static const u_char *
krb4_print_hdr(netdissect_options * ndo,const u_char * cp)125 krb4_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
139 trunc:
140 ND_PRINT((ndo, "%s", tstr));
141 return (NULL);
142
143 #undef PRINT
144 }
145
146 static void
krb4_print(netdissect_options * ndo,const u_char * cp)147 krb4_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;
220 trunc:
221 ND_PRINT((ndo, "%s", tstr));
222 }
223
224 void
krb_print(netdissect_options * ndo,const u_char * dat)225 krb_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