source/libnet/libnet_keytab.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    dump the remote SAM using rpc samsync operations
   4
   5    Copyright (C) Guenther Deschner 2008.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "libnet/libnet.h"
  23
  24 #ifdef HAVE_KRB5
  25
  26 /****************************************************************
  27 ****************************************************************/
  28
  29 static int keytab_close(struct libnet_keytab_context *ctx)
  30 {
  31         if (!ctx) {
  32                 return 0;
  33         }
  34
  35         if (ctx->keytab && ctx->context) {
  36                 krb5_kt_close(ctx->context, ctx->keytab);
  37         }
  38
  39         if (ctx->context) {
  40                 krb5_free_context(ctx->context);
  41         }
  42
  43         if (ctx->ads) {
  44                 ads_destroy(&ctx->ads);
  45         }
  46
  47         TALLOC_FREE(ctx);
  48
  49         return 0;
  50 }
  51
  52 /****************************************************************
  53 ****************************************************************/
  54
  55 krb5_error_code libnet_keytab_init(TALLOC_CTX *mem_ctx,
  56                                    const char *keytab_name,
  57                                    struct libnet_keytab_context **ctx)
  58 {
  59         krb5_error_code ret = 0;
  60         krb5_context context = NULL;
  61         krb5_keytab keytab = NULL;
  62         const char *keytab_string = NULL;
  63
  64         struct libnet_keytab_context *r;
  65
  66         r = TALLOC_ZERO_P(mem_ctx, struct libnet_keytab_context);
  67         if (!r) {
  68                 return ENOMEM;
  69         }
  70
  71         talloc_set_destructor(r, keytab_close);
  72
  73         initialize_krb5_error_table();
  74         ret = krb5_init_context(&context);
  75         if (ret) {
  76                 DEBUG(1,("keytab_init: could not krb5_init_context: %s\n",
  77                         error_message(ret)));
  78                 return ret;
  79         }
  80
  81         ret = smb_krb5_open_keytab(context, keytab_name, true, &keytab);
  82         if (ret) {
  83                 DEBUG(1,("keytab_init: smb_krb5_open_keytab failed (%s)\n",
  84                         error_message(ret)));
  85                 krb5_free_context(context);
  86                 return ret;
  87         }
  88
  89         ret = smb_krb5_keytab_name(mem_ctx, context, keytab, &keytab_string);
  90         if (ret) {
  91                 krb5_kt_close(context, keytab);
  92                 krb5_free_context(context);
  93                 return ret;
  94         }
  95
  96         r->context = context;
  97         r->keytab = keytab;
  98         r->keytab_name = keytab_string;
  99
 100         *ctx = r;
 101
 102         return 0;
 103 }
 104
 105 /****************************************************************
 106 ****************************************************************/
 107
 108 krb5_error_code libnet_keytab_add(struct libnet_keytab_context *ctx)
 109 {
 110 #if defined(ENCTYPE_ARCFOUR_HMAC)
 111         krb5_error_code ret = 0;
 112         krb5_enctype enctypes[2] = { ENCTYPE_ARCFOUR_HMAC, 0 };
 113         int i;
 114
 115         for (i=0; i<ctx->count; i++) {
 116
 117                 struct libnet_keytab_entry *entry = &ctx->entries[i];
 118                 krb5_data password;
 119
 120                 password.data = (char *)entry->password.data;
 121                 password.length = entry->password.length;
 122
 123                 ret = smb_krb5_kt_add_entry_ext(ctx->context,
 124                                                 ctx->keytab,
 125                                                 entry->kvno,
 126                                                 entry->principal,
 127                                                 enctypes,
 128                                                 password,
 129                                                 true,
 130                                                 true);
 131                 if (ret) {
 132                         DEBUG(1,("libnet_keytab_add: "
 133                                 "Failed to add entry to keytab file\n"));
 134                         return ret;
 135                 }
 136         }
 137
 138         return ret;
 139 #else
 140         return -1;
 141 #endif /* defined(ENCTYPE_ARCFOUR_HMAC) */
 142 }
 143
 144 struct libnet_keytab_entry *libnet_keytab_search(struct libnet_keytab_context *ctx,
 145                                                  const char *principal, int kvno,
 146                                                  const krb5_enctype enctype,
 147                                                  TALLOC_CTX *mem_ctx)
 148 {
 149         krb5_error_code ret = 0;
 150         krb5_kt_cursor cursor;
 151         krb5_keytab_entry kt_entry;
 152         struct libnet_keytab_entry *entry = NULL;
 153
 154         ZERO_STRUCT(kt_entry);
 155         ZERO_STRUCT(cursor);
 156
 157         ret = krb5_kt_start_seq_get(ctx->context, ctx->keytab, &cursor);
 158         if (ret) {
 159                 return NULL;
 160         }
 161
 162         while (krb5_kt_next_entry(ctx->context, ctx->keytab, &kt_entry, &cursor) == 0) {
 163                 char *princ_s = NULL;
 164
 165                 if (kt_entry.vno != kvno) {
 166                         smb_krb5_kt_free_entry(ctx->context, &kt_entry);
 167                         continue;
 168                 }
 169
 170                 if (kt_entry.key.enctype != enctype) {
 171                         smb_krb5_kt_free_entry(ctx->context, &kt_entry);
 172                         continue;
 173                 }
 174
 175                 ret = smb_krb5_unparse_name(ctx->context, kt_entry.principal, &princ_s);
 176                 if (ret) {
 177                         smb_krb5_kt_free_entry(ctx->context, &kt_entry);
 178                         continue;
 179                 }
 180
 181                 if (strcmp(principal, princ_s) != 0) {
 182                         smb_krb5_kt_free_entry(ctx->context, &kt_entry);
 183                         SAFE_FREE(princ_s);
 184                         continue;
 185                 }
 186
 187                 entry = talloc_zero(mem_ctx, struct libnet_keytab_entry);
 188                 if (!entry) {
 189                         smb_krb5_kt_free_entry(ctx->context, &kt_entry);
 190                         SAFE_FREE(princ_s);
 191                         break;
 192                 }
 193
 194                 entry->name = talloc_strdup(entry, princ_s);
 195                 if (!entry->name) {
 196                         smb_krb5_kt_free_entry(ctx->context, &kt_entry);
 197                         SAFE_FREE(princ_s);
 198                         TALLOC_FREE(entry);
 199                         break;
 200                 }
 201
 202                 entry->principal = talloc_strdup(entry, princ_s);
 203                 if (!entry->principal) {
 204                         smb_krb5_kt_free_entry(ctx->context, &kt_entry);
 205                         SAFE_FREE(princ_s);
 206                         TALLOC_FREE(entry);
 207                         break;
 208                 }
 209
 210                 entry->password = data_blob_talloc(entry, kt_entry.key.contents, kt_entry.key.length);
 211                 if (!entry->password.data) {
 212                         smb_krb5_kt_free_entry(ctx->context, &kt_entry);
 213                         SAFE_FREE(princ_s);
 214                         TALLOC_FREE(entry);
 215                         break;
 216                 }
 217
 218                 smb_krb5_kt_free_entry(ctx->context, &kt_entry);
 219                 SAFE_FREE(princ_s);
 220                 break;
 221         }
 222
 223         krb5_kt_end_seq_get(ctx->context, ctx->keytab, &cursor);
 224         return entry;
 225 }
 226
 227 #endif /* HAVE_KRB5 */