1 /* 2 * Copyright (c) 1999 - 2002 Kungliga Tekniska H�gskolan 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 "hdb_locl.h" 35 36 /* keytab backend for HDB databases */ 37 38 RCSID("$Id: keytab.c 18380 2006-10-09 12:36:40Z lha $"); 39 40 struct hdb_data { 41 char *dbname; 42 char *mkey; 43 }; 44 45 /* 46 * the format for HDB keytabs is: 47 * HDB:[database:file:mkey] 48 */ 49 50 static krb5_error_code 51 hdb_resolve(krb5_context context, const char *name, krb5_keytab id) 52 { 53 struct hdb_data *d; 54 const char *db, *mkey; 55 56 d = malloc(sizeof(*d)); 57 if(d == NULL) { 58 krb5_set_error_string(context, "malloc: out of memory"); 59 return ENOMEM; 60 } 61 db = name; 62 mkey = strchr(name, ':'); 63 if(mkey == NULL || mkey[1] == '\0') { 64 if(*name == '\0') 65 d->dbname = NULL; 66 else { 67 d->dbname = strdup(name); 68 if(d->dbname == NULL) { 69 free(d); 70 krb5_set_error_string(context, "malloc: out of memory"); 71 return ENOMEM; 72 } 73 } 74 d->mkey = NULL; 75 } else { 76 if((mkey - db) == 0) { 77 d->dbname = NULL; 78 } else { 79 d->dbname = malloc(mkey - db + 1); 80 if(d->dbname == NULL) { 81 free(d); 82 krb5_set_error_string(context, "malloc: out of memory"); 83 return ENOMEM; 84 } 85 memmove(d->dbname, db, mkey - db); 86 d->dbname[mkey - db] = '\0'; 87 } 88 d->mkey = strdup(mkey + 1); 89 if(d->mkey == NULL) { 90 free(d->dbname); 91 free(d); 92 krb5_set_error_string(context, "malloc: out of memory"); 93 return ENOMEM; 94 } 95 } 96 id->data = d; 97 return 0; 98 } 99 100 static krb5_error_code 101 hdb_close(krb5_context context, krb5_keytab id) 102 { 103 struct hdb_data *d = id->data; 104 105 free(d->dbname); 106 free(d->mkey); 107 free(d); 108 return 0; 109 } 110 111 static krb5_error_code 112 hdb_get_name(krb5_context context, 113 krb5_keytab id, 114 char *name, 115 size_t namesize) 116 { 117 struct hdb_data *d = id->data; 118 119 snprintf(name, namesize, "%s%s%s", 120 d->dbname ? d->dbname : "", 121 (d->dbname || d->mkey) ? ":" : "", 122 d->mkey ? d->mkey : ""); 123 return 0; 124 } 125 126 static void 127 set_config (krb5_context context, 128 const krb5_config_binding *binding, 129 const char **dbname, 130 const char **mkey) 131 { 132 *dbname = krb5_config_get_string(context, binding, "dbname", NULL); 133 *mkey = krb5_config_get_string(context, binding, "mkey_file", NULL); 134 } 135 136 /* 137 * try to figure out the database (`dbname') and master-key (`mkey') 138 * that should be used for `principal'. 139 */ 140 141 static void 142 find_db (krb5_context context, 143 const char **dbname, 144 const char **mkey, 145 krb5_const_principal principal) 146 { 147 const krb5_config_binding *top_bind = NULL; 148 const krb5_config_binding *default_binding = NULL; 149 const krb5_config_binding *db; 150 krb5_realm *prealm = krb5_princ_realm(context, rk_UNCONST(principal)); 151 152 *dbname = *mkey = NULL; 153 154 while ((db = 155 krb5_config_get_next(context, 156 NULL, 157 &top_bind, 158 krb5_config_list, 159 "kdc", 160 "database", 161 NULL)) != NULL) { 162 const char *p; 163 164 p = krb5_config_get_string (context, db, "realm", NULL); 165 if (p == NULL) { 166 if(default_binding) { 167 krb5_warnx(context, "WARNING: more than one realm-less " 168 "database specification"); 169 krb5_warnx(context, "WARNING: using the first encountered"); 170 } else 171 default_binding = db; 172 } else if (strcmp (*prealm, p) == 0) { 173 set_config (context, db, dbname, mkey); 174 break; 175 } 176 } 177 if (*dbname == NULL && default_binding != NULL) 178 set_config (context, default_binding, dbname, mkey); 179 if (*dbname == NULL) 180 *dbname = HDB_DEFAULT_DB; 181 } 182 183 /* 184 * find the keytab entry in `id' for `principal, kvno, enctype' and return 185 * it in `entry'. return 0 or an error code 186 */ 187 188 static krb5_error_code 189 hdb_get_entry(krb5_context context, 190 krb5_keytab id, 191 krb5_const_principal principal, 192 krb5_kvno kvno, 193 krb5_enctype enctype, 194 krb5_keytab_entry *entry) 195 { 196 hdb_entry_ex ent; 197 krb5_error_code ret; 198 struct hdb_data *d = id->data; 199 int i; 200 HDB *db; 201 const char *dbname = d->dbname; 202 const char *mkey = d->mkey; 203 204 memset(&ent, 0, sizeof(ent)); 205 206 if (dbname == NULL) 207 find_db (context, &dbname, &mkey, principal); 208 209 ret = hdb_create (context, &db, dbname); 210 if (ret) 211 return ret; 212 ret = hdb_set_master_keyfile (context, db, mkey); 213 if (ret) { 214 (*db->hdb_destroy)(context, db); 215 return ret; 216 } 217 218 ret = (*db->hdb_open)(context, db, O_RDONLY, 0); 219 if (ret) { 220 (*db->hdb_destroy)(context, db); 221 return ret; 222 } 223 ret = (*db->hdb_fetch)(context, db, principal, 224 HDB_F_DECRYPT| 225 HDB_F_GET_CLIENT|HDB_F_GET_SERVER|HDB_F_GET_KRBTGT, 226 &ent); 227 228 if(ret == HDB_ERR_NOENTRY) { 229 ret = KRB5_KT_NOTFOUND; 230 goto out; 231 }else if(ret) 232 goto out; 233 234 if(kvno && ent.entry.kvno != kvno) { 235 hdb_free_entry(context, &ent); 236 ret = KRB5_KT_NOTFOUND; 237 goto out; 238 } 239 if(enctype == 0) 240 if(ent.entry.keys.len > 0) 241 enctype = ent.entry.keys.val[0].key.keytype; 242 ret = KRB5_KT_NOTFOUND; 243 for(i = 0; i < ent.entry.keys.len; i++) { 244 if(ent.entry.keys.val[i].key.keytype == enctype) { 245 krb5_copy_principal(context, principal, &entry->principal); 246 entry->vno = ent.entry.kvno; 247 krb5_copy_keyblock_contents(context, 248 &ent.entry.keys.val[i].key, 249 &entry->keyblock); 250 ret = 0; 251 break; 252 } 253 } 254 hdb_free_entry(context, &ent); 255 out: 256 (*db->hdb_close)(context, db); 257 (*db->hdb_destroy)(context, db); 258 return ret; 259 } 260 261 krb5_kt_ops hdb_kt_ops = { 262 "HDB", 263 hdb_resolve, 264 hdb_get_name, 265 hdb_close, 266 hdb_get_entry, 267 NULL, /* start_seq_get */ 268 NULL, /* next_entry */ 269 NULL, /* end_seq_get */ 270 NULL, /* add */ 271 NULL /* remove */ 272 }; 273