kuser/kimpersonate.c

   1 /*
   2  * Copyright (c) 2000 - 2007 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "kuser_locl.h"
  35 #include <parse_units.h>
  36
  37 static char *client_principal_str = NULL;
  38 static krb5_principal client_principal;
  39 static char *server_principal_str = NULL;
  40 static krb5_principal server_principal;
  41
  42 static char *ccache_str = NULL;
  43
  44 static char *ticket_flags_str = NULL;
  45 static TicketFlags ticket_flags;
  46 static char *keytab_file = NULL;
  47 static char *enc_type = "des-cbc-md5";
  48 static int   expiration_time = 3600;
  49 static struct getarg_strings client_addresses;
  50 static int   version_flag = 0;
  51 static int   help_flag = 0;
  52 static int   use_krb5 = 1;
  53
  54 /*
  55  *
  56  */
  57
  58 static void
  59 encode_ticket (krb5_context context,
  60                EncryptionKey *skey,
  61                krb5_enctype etype,
  62                int skvno,
  63                krb5_creds *cred)
  64 {
  65     size_t len, size;
  66     char *buf;
  67     krb5_error_code ret;
  68     krb5_crypto crypto;
  69     EncryptedData enc_part;
  70     EncTicketPart et;
  71     Ticket ticket;
  72
  73     memset (&enc_part, 0, sizeof(enc_part));
  74     memset (&ticket, 0, sizeof(ticket));
  75
  76     /*
  77      * Set up `enc_part'
  78      */
  79
  80     et.flags = cred->flags.b;
  81     et.key = cred->session;
  82     et.crealm = cred->client->realm;
  83     copy_PrincipalName(&cred->client->name, &et.cname);
  84     {
  85         krb5_data empty_string;
  86
  87         krb5_data_zero(&empty_string);
  88         et.transited.tr_type = DOMAIN_X500_COMPRESS;
  89         et.transited.contents = empty_string;
  90     }
  91     et.authtime = cred->times.authtime;
  92     et.starttime = NULL;
  93     et.endtime = cred->times.endtime;
  94     et.renew_till = NULL;
  95     et.caddr = &cred->addresses;
  96     et.authorization_data = NULL; /* XXX allow random authorization_data */
  97
  98     /*
  99      * Encrypt `enc_part' of ticket with service key
 100      */
 101
 102     ASN1_MALLOC_ENCODE(EncTicketPart, buf, len, &et, &size, ret);
 103     if (ret)
 104         krb5_err(context, 1, ret, "EncTicketPart");
 105
 106     ret = krb5_crypto_init(context, skey, etype, &crypto);
 107     if (ret)
 108         krb5_err(context, 1, ret, "krb5_crypto_init");
 109     ret = krb5_encrypt_EncryptedData (context,
 110                                       crypto,
 111                                       KRB5_KU_TICKET,
 112                                       buf,
 113                                       len,
 114                                       skvno,
 115                                       &ticket.enc_part);
 116     if (ret)
 117         krb5_err(context, 1, ret, "krb5_encrypt_EncryptedData");
 118
 119     free(buf);
 120     krb5_crypto_destroy(context, crypto);
 121
 122     /*
 123      * Encode ticket
 124      */
 125
 126     ticket.tkt_vno = 5;
 127     ticket.realm = cred->server->realm;
 128     copy_PrincipalName(&cred->server->name, &ticket.sname);
 129
 130     ASN1_MALLOC_ENCODE(Ticket, buf, len, &ticket, &size, ret);
 131     if(ret)
 132         krb5_err (context, 1, ret, "encode_Ticket");
 133
 134     krb5_data_copy(&cred->ticket, buf, len);
 135     free(buf);
 136 }
 137
 138 /*
 139  *
 140  */
 141
 142 static int
 143 create_krb5_tickets (krb5_context context, krb5_keytab kt)
 144 {
 145     krb5_error_code ret;
 146     krb5_keytab_entry entry;
 147     krb5_creds cred;
 148     krb5_enctype etype;
 149     krb5_ccache ccache;
 150
 151     memset (&cred, 0, sizeof(cred));
 152
 153     ret = krb5_string_to_enctype (context, enc_type, &etype);
 154     if (ret)
 155         krb5_err (context, 1, ret, "krb5_string_to_enctype");
 156     ret = krb5_kt_get_entry (context, kt, server_principal,
 157                              0, etype, &entry);
 158     if (ret)
 159         krb5_err (context, 1, ret, "krb5_kt_get_entry");
 160
 161     /*
 162      * setup cred
 163      */
 164
 165
 166     ret = krb5_copy_principal (context, client_principal, &cred.client);
 167     if (ret)
 168         krb5_err (context, 1, ret, "krb5_copy_principal");
 169     ret = krb5_copy_principal (context, server_principal, &cred.server);
 170     if (ret)
 171         krb5_err (context, 1, ret, "krb5_copy_principal");
 172     krb5_generate_random_keyblock(context, etype, &cred.session);
 173
 174     cred.times.authtime = time(NULL);
 175     cred.times.starttime = time(NULL);
 176     cred.times.endtime = time(NULL) + expiration_time;
 177     cred.times.renew_till = 0;
 178     krb5_data_zero(&cred.second_ticket);
 179
 180     ret = krb5_get_all_client_addrs (context, &cred.addresses);
 181     if (ret)
 182         krb5_err (context, 1, ret, "krb5_get_all_client_addrs");
 183     cred.flags.b = ticket_flags;
 184
 185
 186     /*
 187      * Encode encrypted part of ticket
 188      */
 189
 190     encode_ticket (context, &entry.keyblock, etype, entry.vno, &cred);
 191
 192     /*
 193      * Write to cc
 194      */
 195
 196     if (ccache_str) {
 197         ret = krb5_cc_resolve(context, ccache_str, &ccache);
 198         if (ret)
 199             krb5_err (context, 1, ret, "krb5_cc_resolve");
 200     } else {
 201         ret = krb5_cc_default (context, &ccache);
 202         if (ret)
 203             krb5_err (context, 1, ret, "krb5_cc_default");
 204     }
 205
 206     ret = krb5_cc_initialize (context, ccache, cred.client);
 207     if (ret)
 208         krb5_err (context, 1, ret, "krb5_cc_initialize");
 209
 210     ret = krb5_cc_store_cred (context, ccache, &cred);
 211     if (ret)
 212         krb5_err (context, 1, ret, "krb5_cc_store_cred");
 213
 214     krb5_free_cred_contents (context, &cred);
 215     krb5_cc_close (context, ccache);
 216
 217     return 0;
 218 }
 219
 220 /*
 221  *
 222  */
 223
 224 static void
 225 setup_env (krb5_context context, krb5_keytab *kt)
 226 {
 227     krb5_error_code ret;
 228
 229     if (keytab_file)
 230         ret = krb5_kt_resolve (context, keytab_file, kt);
 231     else
 232         ret = krb5_kt_default (context, kt);
 233     if (ret)
 234         krb5_err (context, 1, ret, "resolving keytab");
 235
 236     if (client_principal_str == NULL)
 237         krb5_errx (context, 1, "missing client principal");
 238     ret = krb5_parse_name (context, client_principal_str, &client_principal);
 239     if (ret)
 240         krb5_err (context, 1, ret, "resolvning client name");
 241
 242     if (server_principal_str == NULL)
 243         krb5_errx (context, 1, "missing server principal");
 244     ret = krb5_parse_name (context, server_principal_str, &server_principal);
 245     if (ret)
 246         krb5_err (context, 1, ret, "resolvning client name");
 247
 248     if (ticket_flags_str) {
 249         int ticket_flags_int;
 250
 251         ticket_flags_int = parse_flags(ticket_flags_str,
 252                                        asn1_TicketFlags_units(), 0);
 253         if (ticket_flags_int <= 0) {
 254             krb5_warnx (context, "bad ticket flags: `%s'", ticket_flags_str);
 255             print_flags_table (asn1_TicketFlags_units(), stderr);
 256             exit (1);
 257         }
 258         if (ticket_flags_int)
 259             ticket_flags = int2TicketFlags (ticket_flags_int);
 260     }
 261 }
 262
 263 /*
 264  *
 265  */
 266
 267 struct getargs args[] = {
 268     { "ccache", 0, arg_string, &ccache_str,
 269       "name of kerberos 5 credential cache", "cache-name"},
 270     { "server", 's', arg_string, &server_principal_str,
 271       "name of server principal" },
 272     { "client", 'c', arg_string, &client_principal_str,
 273       "name of client principal" },
 274     { "keytab", 'k', arg_string, &keytab_file,
 275       "name of keytab file" },
 276     { "krb5", '5', arg_flag,     &use_krb5,
 277       "create a kerberos 5 ticket"},
 278     { "expire-time", 'e', arg_integer, &expiration_time,
 279       "lifetime of ticket in seconds" },
 280     { "client-addresses", 'a', arg_strings, &client_addresses,
 281       "addresses of client" },
 282     { "enc-type", 't', arg_string,      &enc_type,
 283       "encryption type" },
 284     { "ticket-flags", 'f', arg_string,   &ticket_flags_str,
 285       "ticket flags for krb5 ticket" },
 286     { "version", 0,  arg_flag,          &version_flag,  "Print version",
 287       NULL },
 288     { "help",    0,  arg_flag,          &help_flag,     NULL,
 289       NULL }
 290 };
 291
 292 static void
 293 usage (int ret)
 294 {
 295     arg_printusage (args,
 296                     sizeof(args) / sizeof(args[0]),
 297                     NULL,
 298                     "");
 299     exit (ret);
 300 }
 301
 302 int
 303 main (int argc, char **argv)
 304 {
 305     int optind = 0;
 306     krb5_error_code ret;
 307     krb5_context context;
 308     krb5_keytab kt;
 309
 310     setprogname (argv[0]);
 311
 312     ret = krb5_init_context (&context);
 313     if (ret)
 314         errx(1, "krb5_init_context failed: %u", ret);
 315
 316     if (getarg (args, sizeof(args) / sizeof(args[0]), argc, argv,
 317                 &optind))
 318         usage (1);
 319
 320     if (help_flag)
 321         usage (0);
 322
 323     if (version_flag) {
 324         print_version(NULL);
 325         return 0;
 326     }
 327
 328     setup_env (context, &kt);
 329
 330     if (use_krb5)
 331         create_krb5_tickets (context, kt);
 332
 333     krb5_kt_close (context, kt);
 334     return 0;
 335 }