source/libads/kerberos.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    kerberos utility library
   4    Copyright (C) Andrew Tridgell 2001
   5    Copyright (C) Remus Koos 2001
   6
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 #include "includes.h"
  24
  25 #ifdef HAVE_KRB5
  26
  27 /*
  28   we use a prompter to avoid a crash bug in the kerberos libs when
  29   dealing with empty passwords
  30   this prompter is just a string copy ...
  31 */
  32 static krb5_error_code
  33 kerb_prompter(krb5_context ctx, void *data,
  34                const char *name,
  35                const char *banner,
  36                int num_prompts,
  37                krb5_prompt prompts[])
  38 {
  39         if (num_prompts == 0) return 0;
  40
  41         memset(prompts[0].reply->data, 0, prompts[0].reply->length);
  42         if (prompts[0].reply->length > 0) {
  43                 if (data) {
  44                         strncpy(prompts[0].reply->data, data, prompts[0].reply->length-1);
  45                         prompts[0].reply->length = strlen(prompts[0].reply->data);
  46                 } else {
  47                         prompts[0].reply->length = 0;
  48                 }
  49         }
  50         return 0;
  51 }
  52
  53 /*
  54   simulate a kinit, putting the tgt in the default cache location
  55   remus@snapserver.com
  56 */
  57 int kerberos_kinit_password(const char *principal, const char *password, int time_offset, time_t *expire_time)
  58 {
  59         krb5_context ctx;
  60         krb5_error_code code = 0;
  61         krb5_ccache cc;
  62         krb5_principal me;
  63         krb5_creds my_creds;
  64
  65         if ((code = krb5_init_context(&ctx)))
  66                 return code;
  67
  68         if (time_offset != 0) {
  69                 krb5_set_real_time(ctx, time(NULL) + time_offset, 0);
  70         }
  71
  72         if ((code = krb5_cc_default(ctx, &cc))) {
  73                 krb5_free_context(ctx);
  74                 return code;
  75         }
  76
  77         if ((code = krb5_parse_name(ctx, principal, &me))) {
  78                 krb5_free_context(ctx);
  79                 return code;
  80         }
  81
  82         if ((code = krb5_get_init_creds_password(ctx, &my_creds, me, NULL,
  83                                                  kerb_prompter,
  84                                                  password, 0, NULL, NULL))) {
  85                 krb5_free_principal(ctx, me);
  86                 krb5_free_context(ctx);
  87                 return code;
  88         }
  89
  90         if ((code = krb5_cc_initialize(ctx, cc, me))) {
  91                 krb5_free_cred_contents(ctx, &my_creds);
  92                 krb5_free_principal(ctx, me);
  93                 krb5_free_context(ctx);
  94                 return code;
  95         }
  96
  97         if ((code = krb5_cc_store_cred(ctx, cc, &my_creds))) {
  98                 krb5_cc_close(ctx, cc);
  99                 krb5_free_cred_contents(ctx, &my_creds);
 100                 krb5_free_principal(ctx, me);
 101                 krb5_free_context(ctx);
 102                 return code;
 103         }
 104
 105         if (expire_time)
 106                 *expire_time = (time_t) my_creds.times.endtime;
 107
 108         krb5_cc_close(ctx, cc);
 109         krb5_free_cred_contents(ctx, &my_creds);
 110         krb5_free_principal(ctx, me);
 111         krb5_free_context(ctx);
 112
 113         return 0;
 114 }
 115
 116
 117
 118 /* run kinit to setup our ccache */
 119 int ads_kinit_password(ADS_STRUCT *ads)
 120 {
 121         char *s;
 122         int ret;
 123
 124         if (asprintf(&s, "%s@%s", ads->auth.user_name, ads->auth.realm) == -1) {
 125                 return KRB5_CC_NOMEM;
 126         }
 127
 128         if (!ads->auth.password) {
 129                 return KRB5_LIBOS_CANTREADPWD;
 130         }
 131
 132         ret = kerberos_kinit_password(s, ads->auth.password, ads->auth.time_offset, &ads->auth.expire);
 133
 134         if (ret) {
 135                 DEBUG(0,("kerberos_kinit_password %s failed: %s\n",
 136                          s, error_message(ret)));
 137         }
 138         free(s);
 139         return ret;
 140 }
 141
 142 int ads_kdestroy(const char *cc_name)
 143 {
 144         krb5_error_code code;
 145         krb5_context ctx;
 146         krb5_ccache cc;
 147
 148         if ((code = krb5_init_context (&ctx))) {
 149                 DEBUG(3, ("ads_kdestroy: kdb5_init_context rc=%d\n", code));
 150                 return code;
 151         }
 152
 153         if (!cc_name) {
 154                 if ((code = krb5_cc_default(ctx, &cc))) {
 155                         krb5_free_context(ctx);
 156                         return code;
 157                 }
 158         } else {
 159                 if ((code = krb5_cc_resolve(ctx, cc_name, &cc))) {
 160                         DEBUG(3, ("ads_kdestroy: krb5_cc_resolve rc=%d\n",
 161                                   code));
 162                         krb5_free_context(ctx);
 163                         return code;
 164                 }
 165         }
 166
 167         if ((code = krb5_cc_destroy (ctx, cc))) {
 168                 DEBUG(3, ("ads_kdestroy: krb5_cc_destroy rc=%d\n", code));
 169         }
 170
 171         krb5_free_context (ctx);
 172         return code;
 173 }
 174
 175 #endif