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 #include <config.h> 27 28 #include "netdissect-stdinc.h" 29 30 #include "netdissect.h" 31 #include "extract.h" 32 33 /* 34 * Kerberos 4: 35 * 36 * Athena Technical Plan 37 * Section E.2.1 38 * Kerberos Authentication and Authorization System 39 * by S. P. Miller, B. C. Neuman, J. I. Schiller, and J. H. Saltzer 40 * 41 * https://web.mit.edu/Saltzer/www/publications/athenaplan/e.2.1.pdf 42 * 43 * 7. Appendix I Design Specifications 44 * 45 * Kerberos 5: 46 * 47 * RFC 1510, RFC 2630, etc. 48 */ 49 50 51 static const u_char *c_print(netdissect_options *, const u_char *, const u_char *); 52 static const u_char *krb4_print_hdr(netdissect_options *, const u_char *); 53 static void krb4_print(netdissect_options *, const u_char *); 54 55 #define AUTH_MSG_KDC_REQUEST 1<<1 56 #define AUTH_MSG_KDC_REPLY 2<<1 57 #define AUTH_MSG_APPL_REQUEST 3<<1 58 #define AUTH_MSG_APPL_REQUEST_MUTUAL 4<<1 59 #define AUTH_MSG_ERR_REPLY 5<<1 60 #define AUTH_MSG_PRIVATE 6<<1 61 #define AUTH_MSG_SAFE 7<<1 62 #define AUTH_MSG_APPL_ERR 8<<1 63 #define AUTH_MSG_DIE 63<<1 64 65 #define KERB_ERR_OK 0 66 #define KERB_ERR_NAME_EXP 1 67 #define KERB_ERR_SERVICE_EXP 2 68 #define KERB_ERR_AUTH_EXP 3 69 #define KERB_ERR_PKT_VER 4 70 #define KERB_ERR_NAME_MAST_KEY_VER 5 71 #define KERB_ERR_SERV_MAST_KEY_VER 6 72 #define KERB_ERR_BYTE_ORDER 7 73 #define KERB_ERR_PRINCIPAL_UNKNOWN 8 74 #define KERB_ERR_PRINCIPAL_NOT_UNIQUE 9 75 #define KERB_ERR_NULL_KEY 10 76 77 struct krb { 78 nd_uint8_t pvno; /* Protocol Version */ 79 nd_uint8_t type; /* Type+B */ 80 }; 81 82 static const struct tok type2str[] = { 83 { AUTH_MSG_KDC_REQUEST, "KDC_REQUEST" }, 84 { AUTH_MSG_KDC_REPLY, "KDC_REPLY" }, 85 { AUTH_MSG_APPL_REQUEST, "APPL_REQUEST" }, 86 { AUTH_MSG_APPL_REQUEST_MUTUAL, "APPL_REQUEST_MUTUAL" }, 87 { AUTH_MSG_ERR_REPLY, "ERR_REPLY" }, 88 { AUTH_MSG_PRIVATE, "PRIVATE" }, 89 { AUTH_MSG_SAFE, "SAFE" }, 90 { AUTH_MSG_APPL_ERR, "APPL_ERR" }, 91 { AUTH_MSG_DIE, "DIE" }, 92 { 0, NULL } 93 }; 94 95 static const struct tok kerr2str[] = { 96 { KERB_ERR_OK, "OK" }, 97 { KERB_ERR_NAME_EXP, "NAME_EXP" }, 98 { KERB_ERR_SERVICE_EXP, "SERVICE_EXP" }, 99 { KERB_ERR_AUTH_EXP, "AUTH_EXP" }, 100 { KERB_ERR_PKT_VER, "PKT_VER" }, 101 { KERB_ERR_NAME_MAST_KEY_VER, "NAME_MAST_KEY_VER" }, 102 { KERB_ERR_SERV_MAST_KEY_VER, "SERV_MAST_KEY_VER" }, 103 { KERB_ERR_BYTE_ORDER, "BYTE_ORDER" }, 104 { KERB_ERR_PRINCIPAL_UNKNOWN, "PRINCIPAL_UNKNOWN" }, 105 { KERB_ERR_PRINCIPAL_NOT_UNIQUE,"PRINCIPAL_NOT_UNIQUE" }, 106 { KERB_ERR_NULL_KEY, "NULL_KEY"}, 107 { 0, NULL} 108 }; 109 110 static const u_char * 111 c_print(netdissect_options *ndo, 112 const u_char *s, const u_char *ep) 113 { 114 u_char c; 115 int flag; 116 117 flag = 1; 118 while (s < ep) { 119 c = GET_U_1(s); 120 s++; 121 if (c == '\0') { 122 flag = 0; 123 break; 124 } 125 fn_print_char(ndo, c); 126 } 127 if (flag) 128 return NULL; 129 return (s); 130 } 131 132 static const u_char * 133 krb4_print_hdr(netdissect_options *ndo, 134 const u_char *cp) 135 { 136 cp += 2; 137 138 #define PRINT if ((cp = c_print(ndo, cp, ndo->ndo_snapend)) == NULL) goto trunc 139 140 PRINT; 141 ND_PRINT("."); 142 PRINT; 143 ND_PRINT("@"); 144 PRINT; 145 return (cp); 146 147 trunc: 148 nd_print_trunc(ndo); 149 return (NULL); 150 151 #undef PRINT 152 } 153 154 static void 155 krb4_print(netdissect_options *ndo, 156 const u_char *cp) 157 { 158 const struct krb *kp; 159 u_char type; 160 u_short len; 161 162 #define PRINT if ((cp = c_print(ndo, cp, ndo->ndo_snapend)) == NULL) goto trunc 163 /* True if struct krb is little endian */ 164 #define IS_LENDIAN(kp) ((GET_U_1((kp)->type) & 0x01) != 0) 165 #define KTOHSP(kp, cp) (IS_LENDIAN(kp) ? GET_LE_U_2(cp) : GET_BE_U_2(cp)) 166 167 kp = (const struct krb *)cp; 168 169 type = GET_U_1(kp->type) & (0xFF << 1); 170 171 ND_PRINT(" %s %s: ", 172 IS_LENDIAN(kp) ? "le" : "be", tok2str(type2str, NULL, type)); 173 174 switch (type) { 175 176 case AUTH_MSG_KDC_REQUEST: 177 if ((cp = krb4_print_hdr(ndo, cp)) == NULL) 178 return; 179 cp += 4; /* ctime */ 180 ND_PRINT(" %umin ", GET_U_1(cp) * 5); 181 cp++; 182 PRINT; 183 ND_PRINT("."); 184 PRINT; 185 break; 186 187 case AUTH_MSG_APPL_REQUEST: 188 cp += 2; 189 ND_PRINT("v%u ", GET_U_1(cp)); 190 cp++; 191 PRINT; 192 ND_PRINT(" (%u)", GET_U_1(cp)); 193 cp++; 194 ND_PRINT(" (%u)", GET_U_1(cp)); 195 break; 196 197 case AUTH_MSG_KDC_REPLY: 198 if ((cp = krb4_print_hdr(ndo, cp)) == NULL) 199 return; 200 cp += 10; /* timestamp + n + exp + kvno */ 201 len = KTOHSP(kp, cp); 202 ND_PRINT(" (%u)", len); 203 break; 204 205 case AUTH_MSG_ERR_REPLY: 206 if ((cp = krb4_print_hdr(ndo, cp)) == NULL) 207 return; 208 cp += 4; /* timestamp */ 209 ND_PRINT(" %s ", tok2str(kerr2str, NULL, KTOHSP(kp, cp))); 210 cp += 4; 211 PRINT; 212 break; 213 214 default: 215 ND_PRINT("(unknown)"); 216 break; 217 } 218 219 return; 220 trunc: 221 nd_print_trunc(ndo); 222 } 223 224 void 225 krb_print(netdissect_options *ndo, 226 const u_char *dat) 227 { 228 const struct krb *kp; 229 230 ndo->ndo_protocol = "kerberos"; 231 nd_print_protocol(ndo); 232 233 kp = (const struct krb *)dat; 234 235 switch (GET_U_1(kp->pvno)) { 236 237 case 1: 238 case 2: 239 case 3: 240 ND_PRINT(" v%u", GET_U_1(kp->pvno)); 241 break; 242 243 case 4: 244 ND_PRINT(" v%u", GET_U_1(kp->pvno)); 245 krb4_print(ndo, (const u_char *)kp); 246 break; 247 248 case 106: 249 case 107: 250 ND_PRINT(" v5"); 251 /* Decode ASN.1 here "someday" */ 252 break; 253 } 254 } 255