1 #pragma ident "%Z%%M% %I% %E% SMI" 2 /* 3 * kadmin/v5server/keytab.c 4 * 5 * Copyright 1995 by the Massachusetts Institute of Technology. 6 * All Rights Reserved. 7 * 8 * Export of this software from the United States of America may 9 * require a specific license from the United States Government. 10 * It is the responsibility of any person or organization contemplating 11 * export to obtain such a license before exporting. 12 * 13 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and 14 * distribute this software and its documentation for any purpose and 15 * without fee is hereby granted, provided that the above copyright 16 * notice appear in all copies and that both that copyright notice and 17 * this permission notice appear in supporting documentation, and that 18 * the name of M.I.T. not be used in advertising or publicity pertaining 19 * to distribution of the software without specific, written prior 20 * permission. Furthermore if you modify this software you must label 21 * your software as modified software and not distribute it in such a 22 * fashion that it might be confused with the original M.I.T. software. 23 * M.I.T. makes no representations about the suitability of 24 * this software for any purpose. It is provided "as is" without express 25 * or implied warranty. 26 * 27 */ 28 #include <string.h> 29 30 #include "k5-int.h" 31 #include "kdb_kt.h" 32 33 static int 34 is_xrealm_tgt(krb5_context, krb5_const_principal); 35 36 krb5_error_code krb5_ktkdb_close (krb5_context, krb5_keytab); 37 38 krb5_error_code krb5_ktkdb_get_entry (krb5_context, krb5_keytab, krb5_const_principal, 39 krb5_kvno, krb5_enctype, krb5_keytab_entry *); 40 41 static krb5_error_code 42 krb5_ktkdb_get_name(krb5_context context, krb5_keytab keytab, 43 char *name, unsigned int namelen) 44 { 45 if (namelen < sizeof("KDB:")) 46 return KRB5_KT_NAME_TOOLONG; 47 strcpy(name, "KDB:"); 48 return 0; 49 } 50 51 krb5_kt_ops krb5_kt_kdb_ops = { 52 0, 53 "KDB", /* Prefix -- this string should not appear anywhere else! */ 54 krb5_ktkdb_resolve, /* resolve */ 55 krb5_ktkdb_get_name, /* get_name */ 56 krb5_ktkdb_close, /* close */ 57 krb5_ktkdb_get_entry, /* get */ 58 NULL, /* start_seq_get */ 59 NULL, /* get_next */ 60 NULL, /* end_get */ 61 NULL, /* add (extended) */ 62 NULL, /* remove (extended) */ 63 NULL, /* (void *) &krb5_ktfile_ser_entry */ 64 }; 65 66 typedef struct krb5_ktkdb_data { 67 char * name; 68 } krb5_ktkdb_data; 69 70 krb5_error_code 71 krb5_ktkdb_resolve(context, name, id) 72 krb5_context context; 73 const char * name; 74 krb5_keytab * id; 75 { 76 if ((*id = (krb5_keytab) malloc(sizeof(**id))) == NULL) 77 return(ENOMEM); 78 (*id)->ops = &krb5_kt_kdb_ops; 79 (*id)->magic = KV5M_KEYTAB; 80 return(0); 81 } 82 83 krb5_error_code 84 krb5_ktkdb_close(context, kt) 85 krb5_context context; 86 krb5_keytab kt; 87 { 88 /* 89 * This routine is responsible for freeing all memory allocated 90 * for this keytab. There are no system resources that need 91 * to be freed nor are there any open files. 92 * 93 * This routine should undo anything done by krb5_ktkdb_resolve(). 94 */ 95 96 kt->ops = NULL; 97 krb5_xfree(kt); 98 99 return 0; 100 } 101 102 static krb5_context ktkdb_ctx = NULL; 103 104 /* 105 * Set a different context for use with ktkdb_get_entry(). This is 106 * primarily useful for kadmind, where the gssapi library context, 107 * which will be used for the keytab, will necessarily have a 108 * different context than that used by the kadm5 library to access the 109 * database for its own purposes. 110 */ 111 krb5_error_code 112 krb5_ktkdb_set_context(krb5_context ctx) 113 { 114 ktkdb_ctx = ctx; 115 return 0; 116 } 117 118 krb5_error_code 119 krb5_ktkdb_get_entry(in_context, id, principal, kvno, enctype, entry) 120 krb5_context in_context; 121 krb5_keytab id; 122 krb5_const_principal principal; 123 krb5_kvno kvno; 124 krb5_enctype enctype; 125 krb5_keytab_entry * entry; 126 { 127 krb5_context context; 128 krb5_keyblock * master_key; 129 krb5_error_code kerror = 0; 130 krb5_key_data * key_data; 131 krb5_db_entry db_entry; 132 krb5_boolean more = 0; 133 int n = 0; 134 int xrealm_tgt; 135 krb5_boolean similar; 136 137 if (ktkdb_ctx) 138 context = ktkdb_ctx; 139 else 140 context = in_context; 141 142 xrealm_tgt = is_xrealm_tgt(context, principal); 143 144 /* Open database */ 145 /* krb5_db_init(context); */ 146 if ((kerror = krb5_db_inited(context))) 147 return(kerror); 148 149 /* get_principal */ 150 kerror = krb5_db_get_principal(context, principal, & 151 db_entry, &n, &more); 152 if (kerror) { 153 /* krb5_db_close_database(context); */ 154 return(kerror); 155 } 156 if (n != 1) { 157 /* krb5_db_close_database(context); */ 158 return KRB5_KT_NOTFOUND; 159 } 160 161 if (db_entry.attributes & KRB5_KDB_DISALLOW_SVR 162 || db_entry.attributes & KRB5_KDB_DISALLOW_ALL_TIX) { 163 kerror = KRB5_KT_NOTFOUND; 164 goto error; 165 } 166 167 /* match key */ 168 kerror = krb5_db_get_mkey(context, &master_key); 169 if (kerror) 170 goto error; 171 172 /* For cross realm tgts, we match whatever enctype is provided; 173 * for other principals, we only match the first enctype that is 174 * found. Since the TGS and AS code do the same thing, then we 175 * will only successfully decrypt tickets we have issued.*/ 176 kerror = krb5_dbe_find_enctype(context, &db_entry, 177 xrealm_tgt?enctype:-1, 178 -1, kvno, &key_data); 179 if (kerror) 180 goto error; 181 182 183 kerror = krb5_dbekd_decrypt_key_data(context, master_key, 184 key_data, &entry->key, NULL); 185 if (kerror) 186 goto error; 187 188 if (enctype > 0) { 189 kerror = krb5_c_enctype_compare(context, enctype, 190 entry->key.enctype, &similar); 191 if (kerror) 192 goto error; 193 194 if (!similar) { 195 kerror = KRB5_KDB_NO_PERMITTED_KEY; 196 goto error; 197 } 198 } 199 /* 200 * Coerce the enctype of the output keyblock in case we got an 201 * inexact match on the enctype. 202 */ 203 entry->key.enctype = enctype; 204 205 kerror = krb5_copy_principal(context, principal, &entry->principal); 206 if (kerror) 207 goto error; 208 209 /* Close database */ 210 error: 211 krb5_db_free_principal(context, &db_entry, 1); 212 /* krb5_db_close_database(context); */ 213 return(kerror); 214 } 215 216 /* 217 * is_xrealm_tgt: Returns true if the principal is a cross-realm TGT 218 * principal-- a principal with first component krbtgt and second 219 * component not equal to realm. 220 */ 221 static int 222 is_xrealm_tgt(krb5_context context, krb5_const_principal princ) 223 { 224 krb5_data *dat; 225 if (krb5_princ_size(context, princ) != 2) 226 return 0; 227 dat = krb5_princ_component(context, princ, 0); 228 if (strncmp("krbtgt", dat->data, dat->length) != 0) 229 return 0; 230 dat = krb5_princ_component(context, princ, 1); 231 if (dat->length != princ->realm.length) 232 return 1; 233 if (strncmp(dat->data, princ->realm.data, dat->length) == 0) 234 return 0; 235 return 1; 236 237 } 238 239