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 /* \summary: Kerberos printer */
25
26 #ifdef HAVE_CONFIG_H
27 #include <config.h>
28 #endif
29
30 #include "netdissect-stdinc.h"
31
32 #include "netdissect.h"
33 #include "extract.h"
34
35 /*
36 * Kerberos 4:
37 *
38 * Athena Technical Plan
39 * Section E.2.1
40 * Kerberos Authentication and Authorization System
41 * by S. P. Miller, B. C. Neuman, J. I. Schiller, and J. H. Saltzer
42 *
43 * https://web.mit.edu/Saltzer/www/publications/athenaplan/e.2.1.pdf
44 *
45 * 7. Appendix I Design Specifications
46 *
47 * Kerberos 5:
48 *
49 * RFC 1510, RFC 2630, etc.
50 */
51
52
53 static const u_char *c_print(netdissect_options *, const u_char *, const u_char *);
54 static const u_char *krb4_print_hdr(netdissect_options *, const u_char *);
55 static void krb4_print(netdissect_options *, const u_char *);
56
57 #define AUTH_MSG_KDC_REQUEST 1<<1
58 #define AUTH_MSG_KDC_REPLY 2<<1
59 #define AUTH_MSG_APPL_REQUEST 3<<1
60 #define AUTH_MSG_APPL_REQUEST_MUTUAL 4<<1
61 #define AUTH_MSG_ERR_REPLY 5<<1
62 #define AUTH_MSG_PRIVATE 6<<1
63 #define AUTH_MSG_SAFE 7<<1
64 #define AUTH_MSG_APPL_ERR 8<<1
65 #define AUTH_MSG_DIE 63<<1
66
67 #define KERB_ERR_OK 0
68 #define KERB_ERR_NAME_EXP 1
69 #define KERB_ERR_SERVICE_EXP 2
70 #define KERB_ERR_AUTH_EXP 3
71 #define KERB_ERR_PKT_VER 4
72 #define KERB_ERR_NAME_MAST_KEY_VER 5
73 #define KERB_ERR_SERV_MAST_KEY_VER 6
74 #define KERB_ERR_BYTE_ORDER 7
75 #define KERB_ERR_PRINCIPAL_UNKNOWN 8
76 #define KERB_ERR_PRINCIPAL_NOT_UNIQUE 9
77 #define KERB_ERR_NULL_KEY 10
78
79 struct krb {
80 nd_uint8_t pvno; /* Protocol Version */
81 nd_uint8_t type; /* Type+B */
82 };
83
84 static const struct tok type2str[] = {
85 { AUTH_MSG_KDC_REQUEST, "KDC_REQUEST" },
86 { AUTH_MSG_KDC_REPLY, "KDC_REPLY" },
87 { AUTH_MSG_APPL_REQUEST, "APPL_REQUEST" },
88 { AUTH_MSG_APPL_REQUEST_MUTUAL, "APPL_REQUEST_MUTUAL" },
89 { AUTH_MSG_ERR_REPLY, "ERR_REPLY" },
90 { AUTH_MSG_PRIVATE, "PRIVATE" },
91 { AUTH_MSG_SAFE, "SAFE" },
92 { AUTH_MSG_APPL_ERR, "APPL_ERR" },
93 { AUTH_MSG_DIE, "DIE" },
94 { 0, NULL }
95 };
96
97 static const struct tok kerr2str[] = {
98 { KERB_ERR_OK, "OK" },
99 { KERB_ERR_NAME_EXP, "NAME_EXP" },
100 { KERB_ERR_SERVICE_EXP, "SERVICE_EXP" },
101 { KERB_ERR_AUTH_EXP, "AUTH_EXP" },
102 { KERB_ERR_PKT_VER, "PKT_VER" },
103 { KERB_ERR_NAME_MAST_KEY_VER, "NAME_MAST_KEY_VER" },
104 { KERB_ERR_SERV_MAST_KEY_VER, "SERV_MAST_KEY_VER" },
105 { KERB_ERR_BYTE_ORDER, "BYTE_ORDER" },
106 { KERB_ERR_PRINCIPAL_UNKNOWN, "PRINCIPAL_UNKNOWN" },
107 { KERB_ERR_PRINCIPAL_NOT_UNIQUE,"PRINCIPAL_NOT_UNIQUE" },
108 { KERB_ERR_NULL_KEY, "NULL_KEY"},
109 { 0, NULL}
110 };
111
112 static const u_char *
c_print(netdissect_options * ndo,const u_char * s,const u_char * ep)113 c_print(netdissect_options *ndo,
114 const u_char *s, const u_char *ep)
115 {
116 u_char c;
117 int flag;
118
119 flag = 1;
120 while (s < ep) {
121 c = GET_U_1(s);
122 s++;
123 if (c == '\0') {
124 flag = 0;
125 break;
126 }
127 fn_print_char(ndo, c);
128 }
129 if (flag)
130 return NULL;
131 return (s);
132 }
133
134 static const u_char *
krb4_print_hdr(netdissect_options * ndo,const u_char * cp)135 krb4_print_hdr(netdissect_options *ndo,
136 const u_char *cp)
137 {
138 cp += 2;
139
140 #define PRINT if ((cp = c_print(ndo, cp, ndo->ndo_snapend)) == NULL) goto trunc
141
142 PRINT;
143 ND_PRINT(".");
144 PRINT;
145 ND_PRINT("@");
146 PRINT;
147 return (cp);
148
149 trunc:
150 nd_print_trunc(ndo);
151 return (NULL);
152
153 #undef PRINT
154 }
155
156 static void
krb4_print(netdissect_options * ndo,const u_char * cp)157 krb4_print(netdissect_options *ndo,
158 const u_char *cp)
159 {
160 const struct krb *kp;
161 u_char type;
162 u_short len;
163
164 #define PRINT if ((cp = c_print(ndo, cp, ndo->ndo_snapend)) == NULL) goto trunc
165 /* True if struct krb is little endian */
166 #define IS_LENDIAN(kp) ((GET_U_1((kp)->type) & 0x01) != 0)
167 #define KTOHSP(kp, cp) (IS_LENDIAN(kp) ? GET_LE_U_2(cp) : GET_BE_U_2(cp))
168
169 kp = (const struct krb *)cp;
170
171 type = GET_U_1(kp->type) & (0xFF << 1);
172
173 ND_PRINT(" %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(ndo, cp)) == NULL)
180 return;
181 cp += 4; /* ctime */
182 ND_PRINT(" %umin ", GET_U_1(cp) * 5);
183 cp++;
184 PRINT;
185 ND_PRINT(".");
186 PRINT;
187 break;
188
189 case AUTH_MSG_APPL_REQUEST:
190 cp += 2;
191 ND_PRINT("v%u ", GET_U_1(cp));
192 cp++;
193 PRINT;
194 ND_PRINT(" (%u)", GET_U_1(cp));
195 cp++;
196 ND_PRINT(" (%u)", GET_U_1(cp));
197 break;
198
199 case AUTH_MSG_KDC_REPLY:
200 if ((cp = krb4_print_hdr(ndo, cp)) == NULL)
201 return;
202 cp += 10; /* timestamp + n + exp + kvno */
203 len = KTOHSP(kp, cp);
204 ND_PRINT(" (%u)", len);
205 break;
206
207 case AUTH_MSG_ERR_REPLY:
208 if ((cp = krb4_print_hdr(ndo, cp)) == NULL)
209 return;
210 cp += 4; /* timestamp */
211 ND_PRINT(" %s ", tok2str(kerr2str, NULL, KTOHSP(kp, cp)));
212 cp += 4;
213 PRINT;
214 break;
215
216 default:
217 ND_PRINT("(unknown)");
218 break;
219 }
220
221 return;
222 trunc:
223 nd_print_trunc(ndo);
224 }
225
226 void
krb_print(netdissect_options * ndo,const u_char * dat)227 krb_print(netdissect_options *ndo,
228 const u_char *dat)
229 {
230 const struct krb *kp;
231
232 ndo->ndo_protocol = "krb";
233 kp = (const struct krb *)dat;
234
235 if (dat >= ndo->ndo_snapend) {
236 nd_print_trunc(ndo);
237 return;
238 }
239
240 switch (GET_U_1(kp->pvno)) {
241
242 case 1:
243 case 2:
244 case 3:
245 ND_PRINT(" v%u", GET_U_1(kp->pvno));
246 break;
247
248 case 4:
249 ND_PRINT(" v%u", GET_U_1(kp->pvno));
250 krb4_print(ndo, (const u_char *)kp);
251 break;
252
253 case 106:
254 case 107:
255 ND_PRINT(" v5");
256 /* Decode ASN.1 here "someday" */
257 break;
258 }
259 }
260