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 * 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 * 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 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 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