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 *enctype_string = NULL;
  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 static const char *enc_type = "des-cbc-md5";
  55
  56 /*
  57  *
  58  */
  59
  60 static void
  61 encode_ticket (krb5_context context,
  62                EncryptionKey *skey,
  63                krb5_enctype etype,
  64                int skvno,
  65                krb5_creds *cred)
  66 {
  67     size_t len, size;
  68     char *buf;
  69     krb5_error_code ret;
  70     krb5_crypto crypto;
  71     EncryptedData enc_part;
  72     EncTicketPart et;
  73     Ticket ticket;
  74
  75     memset (&enc_part, 0, sizeof(enc_part));
  76     memset (&ticket, 0, sizeof(ticket));
  77
  78     /*
  79      * Set up `enc_part'
  80      */
  81
  82     et.flags = cred->flags.b;
  83     et.key = cred->session;
  84     et.crealm = cred->client->realm;
  85     copy_PrincipalName(&cred->client->name, &et.cname);
  86     {
  87         krb5_data empty_string;
  88
  89         krb5_data_zero(&empty_string);
  90         et.transited.tr_type = DOMAIN_X500_COMPRESS;
  91         et.transited.contents = empty_string;
  92     }
  93     et.authtime = cred->times.authtime;
  94     et.starttime = NULL;
  95     et.endtime = cred->times.endtime;
  96     et.renew_till = NULL;
  97     et.caddr = &cred->addresses;
  98     et.authorization_data = NULL; /* XXX allow random authorization_data */
  99
 100     /*
 101      * Encrypt `enc_part' of ticket with service key
 102      */
 103
 104     ASN1_MALLOC_ENCODE(EncTicketPart, buf, len, &et, &size, ret);
 105     if (ret)
 106         krb5_err(context, 1, ret, "EncTicketPart");
 107
 108     ret = krb5_crypto_init(context, skey, etype, &crypto);
 109     if (ret)
 110         krb5_err(context, 1, ret, "krb5_crypto_init");
 111     ret = krb5_encrypt_EncryptedData (context,
 112                                       crypto,
 113                                       KRB5_KU_TICKET,
 114                                       buf,
 115                                       len,
 116                                       skvno,
 117                                       &ticket.enc_part);
 118     if (ret)
 119         krb5_err(context, 1, ret, "krb5_encrypt_EncryptedData");
 120
 121     free(buf);
 122     krb5_crypto_destroy(context, crypto);
 123
 124     /*
 125      * Encode ticket
 126      */
 127
 128     ticket.tkt_vno = 5;
 129     ticket.realm = cred->server->realm;
 130     copy_PrincipalName(&cred->server->name, &ticket.sname);
 131
 132     ASN1_MALLOC_ENCODE(Ticket, buf, len, &ticket, &size, ret);
 133     if(ret)
 134         krb5_err (context, 1, ret, "encode_Ticket");
 135
 136     krb5_data_copy(&cred->ticket, buf, len);
 137     free(buf);
 138 }
 139
 140 /*
 141  *
 142  */
 143
 144 static int
 145 create_krb5_tickets (krb5_context context, krb5_keytab kt)
 146 {
 147     krb5_error_code ret;
 148     krb5_keytab_entry entry;
 149     krb5_creds cred;
 150     krb5_enctype etype;
 151     krb5_ccache ccache;
 152
 153     memset (&cred, 0, sizeof(cred));
 154
 155     ret = krb5_string_to_enctype (context, enc_type, &etype);
 156     if (ret)
 157         krb5_err (context, 1, ret, "krb5_string_to_enctype");
 158     ret = krb5_kt_get_entry (context, kt, server_principal,
 159                              0, etype, &entry);
 160     if (ret)
 161         krb5_err (context, 1, ret, "krb5_kt_get_entry");
 162
 163     /*
 164      * setup cred
 165      */
 166
 167
 168     ret = krb5_copy_principal (context, client_principal, &cred.client);
 169     if (ret)
 170         krb5_err (context, 1, ret, "krb5_copy_principal");
 171     ret = krb5_copy_principal (context, server_principal, &cred.server);
 172     if (ret)
 173         krb5_err (context, 1, ret, "krb5_copy_principal");
 174     krb5_generate_random_keyblock(context, etype, &cred.session);
 175
 176     cred.times.authtime = time(NULL);
 177     cred.times.starttime = time(NULL);
 178     cred.times.endtime = time(NULL) + expiration_time;
 179     cred.times.renew_till = 0;
 180     krb5_data_zero(&cred.second_ticket);
 181
 182     ret = krb5_get_all_client_addrs (context, &cred.addresses);
 183     if (ret)
 184         krb5_err (context, 1, ret, "krb5_get_all_client_addrs");
 185     cred.flags.b = ticket_flags;
 186
 187
 188     /*
 189      * Encode encrypted part of ticket
 190      */
 191
 192     encode_ticket (context, &entry.keyblock, etype, entry.vno, &cred);
 193
 194     /*
 195      * Write to cc
 196      */
 197
 198     if (ccache_str) {
 199         ret = krb5_cc_resolve(context, ccache_str, &ccache);
 200         if (ret)
 201             krb5_err (context, 1, ret, "krb5_cc_resolve");
 202     } else {
 203         ret = krb5_cc_default (context, &ccache);
 204         if (ret)
 205             krb5_err (context, 1, ret, "krb5_cc_default");
 206     }
 207
 208     ret = krb5_cc_initialize (context, ccache, cred.client);
 209     if (ret)
 210         krb5_err (context, 1, ret, "krb5_cc_initialize");
 211
 212     ret = krb5_cc_store_cred (context, ccache, &cred);
 213     if (ret)
 214         krb5_err (context, 1, ret, "krb5_cc_store_cred");
 215
 216     krb5_free_cred_contents (context, &cred);
 217     krb5_cc_close (context, ccache);
 218
 219     return 0;
 220 }
 221
 222 /*
 223  *
 224  */
 225
 226 static void
 227 setup_env (krb5_context context, krb5_keytab *kt)
 228 {
 229     krb5_error_code ret;
 230
 231     if (keytab_file)
 232         ret = krb5_kt_resolve (context, keytab_file, kt);
 233     else
 234         ret = krb5_kt_default (context, kt);
 235     if (ret)
 236         krb5_err (context, 1, ret, "resolving keytab");
 237
 238     if (client_principal_str == NULL)
 239         krb5_errx (context, 1, "missing client principal");
 240     ret = krb5_parse_name (context, client_principal_str, &client_principal);
 241     if (ret)
 242         krb5_err (context, 1, ret, "resolvning client name");
 243
 244     if (server_principal_str == NULL)
 245         krb5_errx (context, 1, "missing server principal");
 246     ret = krb5_parse_name (context, server_principal_str, &server_principal);
 247     if (ret)
 248         krb5_err (context, 1, ret, "resolvning client name");
 249
 250     if (ticket_flags_str) {
 251         int ticket_flags_int;
 252
 253         ticket_flags_int = parse_flags(ticket_flags_str,
 254                                        asn1_TicketFlags_units(), 0);
 255         if (ticket_flags_int <= 0) {
 256             krb5_warnx (context, "bad ticket flags: `%s'", ticket_flags_str);
 257             print_flags_table (asn1_TicketFlags_units(), stderr);
 258             exit (1);
 259         }
 260         if (ticket_flags_int)
 261             ticket_flags = int2TicketFlags (ticket_flags_int);
 262     }
 263 }
 264
 265 /*
 266  *
 267  */
 268
 269 struct getargs args[] = {
 270     { "ccache", 0, arg_string, &ccache_str,
 271       "name of kerberos 5 credential cache", "cache-name"},
 272     { "server", 's', arg_string, &server_principal_str,
 273       "name of server principal", NULL },
 274     { "client", 'c', arg_string, &client_principal_str,
 275       "name of client principal", NULL },
 276     { "keytab", 'k', arg_string, &keytab_file,
 277       "name of keytab file", NULL },
 278     { "krb5", '5', arg_flag,     &use_krb5,
 279       "create a kerberos 5 ticket", NULL },
 280     { "expire-time", 'e', arg_integer, &expiration_time,
 281       "lifetime of ticket in seconds", NULL },
 282     { "client-addresses", 'a', arg_strings, &client_addresses,
 283       "addresses of client", NULL },
 284     { "enc-type", 't', arg_string,      &enctype_string,
 285       "encryption type", NULL },
 286     { "ticket-flags", 'f', arg_string,   &ticket_flags_str,
 287       "ticket flags for krb5 ticket", NULL },
 288     { "version", 0,  arg_flag,          &version_flag,  "Print version",
 289       NULL },
 290     { "help",    0,  arg_flag,          &help_flag,     NULL,
 291       NULL }
 292 };
 293
 294 static void
 295 usage (int ret)
 296 {
 297     arg_printusage (args,
 298                     sizeof(args) / sizeof(args[0]),
 299                     NULL,
 300                     "");
 301     exit (ret);
 302 }
 303
 304 int
 305 main (int argc, char **argv)
 306 {
 307     int optidx = 0;
 308     krb5_error_code ret;
 309     krb5_context context;
 310     krb5_keytab kt;
 311
 312     setprogname (argv[0]);
 313
 314     ret = krb5_init_context (&context);
 315     if (ret)
 316         errx(1, "krb5_init_context failed: %u", ret);
 317
 318     if (getarg(args, sizeof(args) / sizeof(args[0]), argc, argv, &optidx))
 319         usage(1);
 320
 321     if (help_flag)
 322         usage(0);
 323
 324     if (version_flag) {
 325         print_version(NULL);
 326         return 0;
 327     }
 328
 329     if (enctype_string)
 330         enc_type = enctype_string;
 331
 332     setup_env(context, &kt);
 333
 334     if (use_krb5)
 335         create_krb5_tickets(context, kt);
 336
 337     krb5_kt_close(context, kt);
 338
 339     return 0;
 340 }