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,v 1.5 2002/08/26 13:28:11 assar Exp $"); 39 40 struct hdb_data { 41 char *dbname; 42 char *mkey; 43 }; 44 45 /* 46 * the format for HDB keytabs is: 47 * HDB:[database: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); 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 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 krb5_config_binding *default_binding = NULL; 149 krb5_config_binding *db; 150 krb5_realm *prealm = krb5_princ_realm(context, (krb5_principal)principal); 151 152 *dbname = *mkey = NULL; 153 154 while ((db = (krb5_config_binding *) 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 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 if (dbname == NULL) 205 find_db (context, &dbname, &mkey, principal); 206 207 ret = hdb_create (context, &db, dbname); 208 if (ret) 209 return ret; 210 ret = hdb_set_master_keyfile (context, db, mkey); 211 if (ret) { 212 (*db->destroy)(context, db); 213 return ret; 214 } 215 216 ret = (*db->open)(context, db, O_RDONLY, 0); 217 if (ret) { 218 (*db->destroy)(context, db); 219 return ret; 220 } 221 ent.principal = (krb5_principal)principal; 222 ret = (*db->fetch)(context, db, HDB_F_DECRYPT, &ent); 223 (*db->close)(context, db); 224 (*db->destroy)(context, db); 225 226 if(ret == HDB_ERR_NOENTRY) 227 return KRB5_KT_NOTFOUND; 228 else if(ret) 229 return ret; 230 if(kvno && ent.kvno != kvno) { 231 hdb_free_entry(context, &ent); 232 return KRB5_KT_NOTFOUND; 233 } 234 if(enctype == 0) 235 if(ent.keys.len > 0) 236 enctype = ent.keys.val[0].key.keytype; 237 ret = KRB5_KT_NOTFOUND; 238 for(i = 0; i < ent.keys.len; i++) { 239 if(ent.keys.val[i].key.keytype == enctype) { 240 krb5_copy_principal(context, principal, &entry->principal); 241 entry->vno = ent.kvno; 242 krb5_copy_keyblock_contents(context, 243 &ent.keys.val[i].key, 244 &entry->keyblock); 245 ret = 0; 246 break; 247 } 248 } 249 hdb_free_entry(context, &ent); 250 return ret; 251 } 252 253 krb5_kt_ops hdb_kt_ops = { 254 "HDB", 255 hdb_resolve, 256 hdb_get_name, 257 hdb_close, 258 hdb_get_entry, 259 NULL, /* start_seq_get */ 260 NULL, /* next_entry */ 261 NULL, /* end_seq_get */ 262 NULL, /* add */ 263 NULL /* remove */ 264 }; 265