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     krb5_crypto_init(context, skey, etype, &crypto);
 107     krb5_encrypt_EncryptedData (context,
 108                                 crypto,
 109                                 KRB5_KU_TICKET,
 110                                 buf,
 111                                 len,
 112                                 skvno,
 113                                 &ticket.enc_part);
 114     free(buf);
 115     krb5_crypto_destroy(context, crypto);
 116
 117     /*
 118      * Encode ticket
 119      */
 120
 121     ticket.tkt_vno = 5;
 122     ticket.realm = cred->server->realm;
 123     copy_PrincipalName(&cred->server->name, &ticket.sname);
 124
 125     ASN1_MALLOC_ENCODE(Ticket, buf, len, &ticket, &size, ret);
 126     if(ret)
 127         krb5_err (context, 1, ret, "encode_Ticket");
 128
 129     krb5_data_copy(&cred->ticket, buf, len);
 130     free(buf);
 131 }
 132
 133 /*
 134  *
 135  */
 136
 137 static int
 138 create_krb5_tickets (krb5_context context, krb5_keytab kt)
 139 {
 140     krb5_error_code ret;
 141     krb5_keytab_entry entry;
 142     krb5_creds cred;
 143     krb5_enctype etype;
 144     krb5_ccache ccache;
 145
 146     memset (&cred, 0, sizeof(cred));
 147
 148     ret = krb5_string_to_enctype (context, enc_type, &etype);
 149     if (ret)
 150         krb5_err (context, 1, ret, "krb5_string_to_enctype");
 151     ret = krb5_kt_get_entry (context, kt, server_principal,
 152                              0, etype, &entry);
 153     if (ret)
 154         krb5_err (context, 1, ret, "krb5_kt_get_entry");
 155
 156     /*
 157      * setup cred
 158      */
 159
 160
 161     ret = krb5_copy_principal (context, client_principal, &cred.client);
 162     if (ret)
 163         krb5_err (context, 1, ret, "krb5_copy_principal");
 164     ret = krb5_copy_principal (context, server_principal, &cred.server);
 165     if (ret)
 166         krb5_err (context, 1, ret, "krb5_copy_principal");
 167     krb5_generate_random_keyblock(context, etype, &cred.session);
 168
 169     cred.times.authtime = time(NULL);
 170     cred.times.starttime = time(NULL);
 171     cred.times.endtime = time(NULL) + expiration_time;
 172     cred.times.renew_till = 0;
 173     krb5_data_zero(&cred.second_ticket);
 174
 175     ret = krb5_get_all_client_addrs (context, &cred.addresses);
 176     if (ret)
 177         krb5_err (context, 1, ret, "krb5_get_all_client_addrs");
 178     cred.flags.b = ticket_flags;
 179
 180
 181     /*
 182      * Encode encrypted part of ticket
 183      */
 184
 185     encode_ticket (context, &entry.keyblock, etype, entry.vno, &cred);
 186
 187     /*
 188      * Write to cc
 189      */
 190
 191     if (ccache_str) {
 192         ret = krb5_cc_resolve(context, ccache_str, &ccache);
 193         if (ret)
 194             krb5_err (context, 1, ret, "krb5_cc_resolve");
 195     } else {
 196         ret = krb5_cc_default (context, &ccache);
 197         if (ret)
 198             krb5_err (context, 1, ret, "krb5_cc_default");
 199     }
 200
 201     ret = krb5_cc_initialize (context, ccache, cred.client);
 202     if (ret)
 203         krb5_err (context, 1, ret, "krb5_cc_initialize");
 204
 205     ret = krb5_cc_store_cred (context, ccache, &cred);
 206     if (ret)
 207         krb5_err (context, 1, ret, "krb5_cc_store_cred");
 208
 209     krb5_free_cred_contents (context, &cred);
 210     krb5_cc_close (context, ccache);
 211
 212     return 0;
 213 }
 214
 215 /*
 216  *
 217  */
 218
 219 static void
 220 setup_env (krb5_context context, krb5_keytab *kt)
 221 {
 222     krb5_error_code ret;
 223
 224     if (keytab_file)
 225         ret = krb5_kt_resolve (context, keytab_file, kt);
 226     else
 227         ret = krb5_kt_default (context, kt);
 228     if (ret)
 229         krb5_err (context, 1, ret, "resolving keytab");
 230
 231     if (client_principal_str == NULL)
 232         krb5_errx (context, 1, "missing client principal");
 233     ret = krb5_parse_name (context, client_principal_str, &client_principal);
 234     if (ret)
 235         krb5_err (context, 1, ret, "resolvning client name");
 236
 237     if (server_principal_str == NULL)
 238         krb5_errx (context, 1, "missing server principal");
 239     ret = krb5_parse_name (context, server_principal_str, &server_principal);
 240     if (ret)
 241         krb5_err (context, 1, ret, "resolvning client name");
 242
 243     if (ticket_flags_str) {
 244         int ticket_flags_int;
 245
 246         ticket_flags_int = parse_flags(ticket_flags_str,
 247                                        asn1_TicketFlags_units(), 0);
 248         if (ticket_flags_int <= 0) {
 249             krb5_warnx (context, "bad ticket flags: `%s'", ticket_flags_str);
 250             print_flags_table (asn1_TicketFlags_units(), stderr);
 251             exit (1);
 252         }
 253         if (ticket_flags_int)
 254             ticket_flags = int2TicketFlags (ticket_flags_int);
 255     }
 256 }
 257
 258 /*
 259  *
 260  */
 261
 262 struct getargs args[] = {
 263     { "ccache", 0, arg_string, &ccache_str,
 264       "name of kerberos 5 credential cache", "cache-name"},
 265     { "server", 's', arg_string, &server_principal_str,
 266       "name of server principal" },
 267     { "client", 'c', arg_string, &client_principal_str,
 268       "name of client principal" },
 269     { "keytab", 'k', arg_string, &keytab_file,
 270       "name of keytab file" },
 271     { "krb5", '5', arg_flag,     &use_krb5,
 272       "create a kerberos 5 ticket"},
 273     { "expire-time", 'e', arg_integer, &expiration_time,
 274       "lifetime of ticket in seconds" },
 275     { "client-addresses", 'a', arg_strings, &client_addresses,
 276       "addresses of client" },
 277     { "enc-type", 't', arg_string,      &enc_type,
 278       "encryption type" },
 279     { "ticket-flags", 'f', arg_string,   &ticket_flags_str,
 280       "ticket flags for krb5 ticket" },
 281     { "version", 0,  arg_flag,          &version_flag,  "Print version",
 282       NULL },
 283     { "help",    0,  arg_flag,          &help_flag,     NULL,
 284       NULL }
 285 };
 286
 287 static void
 288 usage (int ret)
 289 {
 290     arg_printusage (args,
 291                     sizeof(args) / sizeof(args[0]),
 292                     NULL,
 293                     "");
 294     exit (ret);
 295 }
 296
 297 int
 298 main (int argc, char **argv)
 299 {
 300     int optind = 0;
 301     krb5_error_code ret;
 302     krb5_context context;
 303     krb5_keytab kt;
 304
 305     setprogname (argv[0]);
 306
 307     ret = krb5_init_context (&context);
 308     if (ret)
 309         errx(1, "krb5_init_context failed: %u", ret);
 310
 311     if (getarg (args, sizeof(args) / sizeof(args[0]), argc, argv,
 312                 &optind))
 313         usage (1);
 314
 315     if (help_flag)
 316         usage (0);
 317
 318     if (version_flag) {
 319         print_version(NULL);
 320         return 0;
 321     }
 322
 323     setup_env (context, &kt);
 324
 325     if (use_krb5)
 326         create_krb5_tickets (context, kt);
 327
 328     krb5_kt_close (context, kt);
 329     return 0;
 330 }