The Tcpdump Group git mirrors - tcpdump/blob - print-krb.c

   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 #ifdef HAVE_CONFIG_H
  25 #include "config.h"
  26 #endif
  27
  28 #include <netdissect-stdinc.h>
  29
  30 #include "netdissect.h"
  31 #include "extract.h"
  32
  33 static const char tstr[] = " [|kerberos]";
  34
  35 static const u_char *c_print(netdissect_options *, register const u_char *, register const u_char *);
  36 static const u_char *krb4_print_hdr(netdissect_options *, const u_char *);
  37 static void krb4_print(netdissect_options *, const u_char *);
  38
  39 #define AUTH_MSG_KDC_REQUEST                    1<<1
  40 #define AUTH_MSG_KDC_REPLY                      2<<1
  41 #define AUTH_MSG_APPL_REQUEST                   3<<1
  42 #define AUTH_MSG_APPL_REQUEST_MUTUAL            4<<1
  43 #define AUTH_MSG_ERR_REPLY                      5<<1
  44 #define AUTH_MSG_PRIVATE                        6<<1
  45 #define AUTH_MSG_SAFE                           7<<1
  46 #define AUTH_MSG_APPL_ERR                       8<<1
  47 #define AUTH_MSG_DIE                            63<<1
  48
  49 #define KERB_ERR_OK                             0
  50 #define KERB_ERR_NAME_EXP                       1
  51 #define KERB_ERR_SERVICE_EXP                    2
  52 #define KERB_ERR_AUTH_EXP                       3
  53 #define KERB_ERR_PKT_VER                        4
  54 #define KERB_ERR_NAME_MAST_KEY_VER              5
  55 #define KERB_ERR_SERV_MAST_KEY_VER              6
  56 #define KERB_ERR_BYTE_ORDER                     7
  57 #define KERB_ERR_PRINCIPAL_UNKNOWN              8
  58 #define KERB_ERR_PRINCIPAL_NOT_UNIQUE           9
  59 #define KERB_ERR_NULL_KEY                       10
  60
  61 struct krb {
  62         uint8_t pvno;           /* Protocol Version */
  63         uint8_t type;           /* Type+B */
  64 };
  65
  66 static const struct tok type2str[] = {
  67         { AUTH_MSG_KDC_REQUEST,         "KDC_REQUEST" },
  68         { AUTH_MSG_KDC_REPLY,           "KDC_REPLY" },
  69         { AUTH_MSG_APPL_REQUEST,        "APPL_REQUEST" },
  70         { AUTH_MSG_APPL_REQUEST_MUTUAL, "APPL_REQUEST_MUTUAL" },
  71         { AUTH_MSG_ERR_REPLY,           "ERR_REPLY" },
  72         { AUTH_MSG_PRIVATE,             "PRIVATE" },
  73         { AUTH_MSG_SAFE,                "SAFE" },
  74         { AUTH_MSG_APPL_ERR,            "APPL_ERR" },
  75         { AUTH_MSG_DIE,                 "DIE" },
  76         { 0,                            NULL }
  77 };
  78
  79 static const struct tok kerr2str[] = {
  80         { KERB_ERR_OK,                  "OK" },
  81         { KERB_ERR_NAME_EXP,            "NAME_EXP" },
  82         { KERB_ERR_SERVICE_EXP,         "SERVICE_EXP" },
  83         { KERB_ERR_AUTH_EXP,            "AUTH_EXP" },
  84         { KERB_ERR_PKT_VER,             "PKT_VER" },
  85         { KERB_ERR_NAME_MAST_KEY_VER,   "NAME_MAST_KEY_VER" },
  86         { KERB_ERR_SERV_MAST_KEY_VER,   "SERV_MAST_KEY_VER" },
  87         { KERB_ERR_BYTE_ORDER,          "BYTE_ORDER" },
  88         { KERB_ERR_PRINCIPAL_UNKNOWN,   "PRINCIPAL_UNKNOWN" },
  89         { KERB_ERR_PRINCIPAL_NOT_UNIQUE,"PRINCIPAL_NOT_UNIQUE" },
  90         { KERB_ERR_NULL_KEY,            "NULL_KEY"},
  91         { 0,                            NULL}
  92 };
  93
  94 static const u_char *
  95 c_print(netdissect_options *ndo,
  96         register const u_char *s, register const u_char *ep)
  97 {
  98         register u_char c;
  99         register int flag;
 100
 101         flag = 1;
 102         while (s < ep) {
 103                 c = *s++;
 104                 if (c == '\0') {
 105                         flag = 0;
 106                         break;
 107                 }
 108                 if (!ND_ISASCII(c)) {
 109                         c = ND_TOASCII(c);
 110                         ND_PRINT((ndo, "M-"));
 111                 }
 112                 if (!ND_ISPRINT(c)) {
 113                         c ^= 0x40;      /* DEL to ?, others to alpha */
 114                         ND_PRINT((ndo, "^"));
 115                 }
 116                 ND_PRINT((ndo, "%c", c));
 117         }
 118         if (flag)
 119                 return NULL;
 120         return (s);
 121 }
 122
 123 static const u_char *
 124 krb4_print_hdr(netdissect_options *ndo,
 125                const u_char *cp)
 126 {
 127         cp += 2;
 128
 129 #define PRINT           if ((cp = c_print(ndo, cp, ndo->ndo_snapend)) == NULL) goto trunc
 130
 131         PRINT;
 132         ND_PRINT((ndo, "."));
 133         PRINT;
 134         ND_PRINT((ndo, "@"));
 135         PRINT;
 136         return (cp);
 137
 138 trunc:
 139         ND_PRINT((ndo, "%s", tstr));
 140         return (NULL);
 141
 142 #undef PRINT
 143 }
 144
 145 static void
 146 krb4_print(netdissect_options *ndo,
 147            const u_char *cp)
 148 {
 149         register const struct krb *kp;
 150         u_char type;
 151         u_short len;
 152
 153 #define PRINT           if ((cp = c_print(ndo, cp, ndo->ndo_snapend)) == NULL) goto trunc
 154 /*  True if struct krb is little endian */
 155 #define IS_LENDIAN(kp)  (((kp)->type & 0x01) != 0)
 156 #define KTOHSP(kp, cp)  (IS_LENDIAN(kp) ? EXTRACT_LE_16BITS(cp) : EXTRACT_16BITS(cp))
 157
 158         kp = (const struct krb *)cp;
 159
 160         if ((&kp->type) >= ndo->ndo_snapend) {
 161                 ND_PRINT((ndo, "%s", tstr));
 162                 return;
 163         }
 164
 165         type = kp->type & (0xFF << 1);
 166
 167         ND_PRINT((ndo, " %s %s: ",
 168             IS_LENDIAN(kp) ? "le" : "be", tok2str(type2str, NULL, type)));
 169
 170         switch (type) {
 171
 172         case AUTH_MSG_KDC_REQUEST:
 173                 if ((cp = krb4_print_hdr(ndo, cp)) == NULL)
 174                         return;
 175                 cp += 4;        /* ctime */
 176                 ND_TCHECK(*cp);
 177                 ND_PRINT((ndo, " %dmin ", *cp++ * 5));
 178                 PRINT;
 179                 ND_PRINT((ndo, "."));
 180                 PRINT;
 181                 break;
 182
 183         case AUTH_MSG_APPL_REQUEST:
 184                 cp += 2;
 185                 ND_TCHECK(*cp);
 186                 ND_PRINT((ndo, "v%d ", *cp++));
 187                 PRINT;
 188                 ND_TCHECK(*cp);
 189                 ND_PRINT((ndo, " (%d)", *cp++));
 190                 ND_TCHECK(*cp);
 191                 ND_PRINT((ndo, " (%d)", *cp));
 192                 break;
 193
 194         case AUTH_MSG_KDC_REPLY:
 195                 if ((cp = krb4_print_hdr(ndo, cp)) == NULL)
 196                         return;
 197                 cp += 10;       /* timestamp + n + exp + kvno */
 198                 ND_TCHECK2(*cp, sizeof(short));
 199                 len = KTOHSP(kp, cp);
 200                 ND_PRINT((ndo, " (%d)", len));
 201                 break;
 202
 203         case AUTH_MSG_ERR_REPLY:
 204                 if ((cp = krb4_print_hdr(ndo, cp)) == NULL)
 205                         return;
 206                 cp += 4;          /* timestamp */
 207                 ND_TCHECK2(*cp, sizeof(short));
 208                 ND_PRINT((ndo, " %s ", tok2str(kerr2str, NULL, KTOHSP(kp, cp))));
 209                 cp += 4;
 210                 PRINT;
 211                 break;
 212
 213         default:
 214                 ND_PRINT((ndo, "(unknown)"));
 215                 break;
 216         }
 217
 218         return;
 219 trunc:
 220         ND_PRINT((ndo, "%s", tstr));
 221 }
 222
 223 void
 224 krb_print(netdissect_options *ndo,
 225           const u_char *dat)
 226 {
 227         register const struct krb *kp;
 228
 229         kp = (const struct krb *)dat;
 230
 231         if (dat >= ndo->ndo_snapend) {
 232                 ND_PRINT((ndo, "%s", tstr));
 233                 return;
 234         }
 235
 236         switch (kp->pvno) {
 237
 238         case 1:
 239         case 2:
 240         case 3:
 241                 ND_PRINT((ndo, " v%d", kp->pvno));
 242                 break;
 243
 244         case 4:
 245                 ND_PRINT((ndo, " v%d", kp->pvno));
 246                 krb4_print(ndo, (const u_char *)kp);
 247                 break;
 248
 249         case 106:
 250         case 107:
 251                 ND_PRINT((ndo, " v5"));
 252                 /* Decode ASN.1 here "someday" */
 253                 break;
 254         }
 255         return;
 256 }