Rework hdb-samba4 to remove useless abstractions.

The function LDB_lookup_principal() has been eliminated, and it's
contents spread back to it's callers.  Removing the abstraction makes
the code clearer.

Also ensure we never pass unescaped user input to a LDB search
function.

Andrew Bartlett

diff --git a/source4/kdc/hdb-samba4.c b/source4/kdc/hdb-samba4.c
index eda7867bb5ea1a135829ffaa23acfdac8ecc1909..17ad20be82bdb63e737fb295d832de5e91f46ff0 100644 (file)
--- a/source4/kdc/hdb-samba4.c
+++ b/source4/kdc/hdb-samba4.c
@@ -909,73 +909,6 @@ out:
 
 }
 
-static krb5_error_code LDB_lookup_principal(krb5_context context, struct ldb_context *ldb_ctx,                                         
-                                           TALLOC_CTX *mem_ctx,
-                                           krb5_const_principal principal,
-                                           enum hdb_ldb_ent_type ent_type,
-                                           struct ldb_dn *realm_dn,
-                                           struct ldb_message **pmsg)
-{
-       krb5_error_code ret;
-       int lret;
-       char *filter = NULL;
-       const char * const *princ_attrs = user_attrs;
-       char *short_princ;
-       char *short_princ_talloc;
-
-       ret = krb5_unparse_name_flags(context, principal,  KRB5_PRINCIPAL_UNPARSE_NO_REALM, &short_princ);
-
-       if (ret != 0) {
-               krb5_set_error_message(context, ret, "LDB_lookup_principal: could not parse principal");
-               krb5_warnx(context, "LDB_lookup_principal: could not parse principal");
-               return ret;
-       }
-
-       short_princ_talloc = talloc_strdup(mem_ctx, short_princ);
-       free(short_princ);
-       if (!short_princ_talloc) {
-               ret = ENOMEM;
-               krb5_set_error_message(context, ret, "LDB_lookup_principal: talloc_strdup() failed!");
-               return ret;
-       }
-
-       switch (ent_type) {
-       case HDB_SAMBA4_ENT_TYPE_CLIENT:
-       case HDB_SAMBA4_ENT_TYPE_TRUST:
-       case HDB_SAMBA4_ENT_TYPE_ANY:
-               /* Can't happen */
-               return EINVAL;
-       case HDB_SAMBA4_ENT_TYPE_KRBTGT:
-               filter = talloc_asprintf(mem_ctx, "(&(objectClass=user)(samAccountName=%s))", 
-                                        KRB5_TGS_NAME);
-               break;
-       case HDB_SAMBA4_ENT_TYPE_SERVER:
-               filter = talloc_asprintf(mem_ctx, "(&(objectClass=user)(samAccountName=%s))", 
-                                        short_princ_talloc);
-               break;
-       }
-
-       if (!filter) {
-               ret = ENOMEM;
-               krb5_set_error_message(context, ret, "talloc_asprintf: out of memory");
-               return ret;
-       }
-
-       lret = gendb_search_single_extended_dn(ldb_ctx, mem_ctx, 
-                                              realm_dn, LDB_SCOPE_SUBTREE,
-                                              pmsg, princ_attrs, "%s", filter);
-       if (lret == LDB_ERR_NO_SUCH_OBJECT) {
-               DEBUG(3, ("Failed find a entry for %s\n", filter));
-               return HDB_ERR_NOENTRY;
-       }
-       if (lret != LDB_SUCCESS) {
-               DEBUG(3, ("Failed single search for for %s - %s\n", 
-                         filter, ldb_errstring(ldb_ctx)));
-               return HDB_ERR_NOENTRY;
-       }
-       return 0;
-}
-
 static krb5_error_code LDB_lookup_trust(krb5_context context, struct ldb_context *ldb_ctx,                                     
                                        TALLOC_CTX *mem_ctx,
                                        const char *realm,
@@ -1107,8 +1040,26 @@ static krb5_error_code LDB_fetch_krbtgt(krb5_context context, HDB *db,
                /* Cludge, cludge cludge.  If the realm part of krbtgt/realm,
                 * is in our db, then direct the caller at our primary
                 * krbtgt */
+
+               int lret;
+               char *realm_fixed;
+               const char * const *princ_attrs = user_attrs;
                
-               char *realm_fixed = strupper_talloc(mem_ctx, lp_realm(lp_ctx));
+               lret = gendb_search_single_extended_dn(db->hdb_db, mem_ctx, 
+                                                      realm_dn, LDB_SCOPE_SUBTREE,
+                                                      &msg, princ_attrs, 
+                                                      "(&(objectClass=user)(samAccountName=krbtgt))"); 
+               if (lret == LDB_ERR_NO_SUCH_OBJECT) {
+                       krb5_warnx(context, "LDB_fetch: could not find own KRBTGT in DB!");
+                       krb5_set_error_message(context, HDB_ERR_NOENTRY, "LDB_fetch: could not find own KRBTGT in DB!");
+                       return HDB_ERR_NOENTRY;
+               } else if (lret != LDB_SUCCESS) {
+                       krb5_warnx(context, "LDB_fetch: could not find own KRBTGT in DB: %s", ldb_errstring(db->hdb_db));
+                       krb5_set_error_message(context, HDB_ERR_NOENTRY, "LDB_fetch: could not find own KRBTGT in DB: %s", ldb_errstring(db->hdb_db));
+                       return HDB_ERR_NOENTRY;
+               }
+               
+               realm_fixed = strupper_talloc(mem_ctx, lp_realm(lp_ctx));
                if (!realm_fixed) {
                        ret = ENOMEM;
                        krb5_set_error_message(context, ret, "strupper_talloc: out of memory");
@@ -1130,16 +1081,6 @@ static krb5_error_code LDB_fetch_krbtgt(krb5_context context, HDB *db,
                }
                principal = alloc_principal;
 
-               ret = LDB_lookup_principal(context, (struct ldb_context *)db->hdb_db, 
-                                          mem_ctx, 
-                                          principal, HDB_SAMBA4_ENT_TYPE_KRBTGT, realm_dn, &msg);
-               
-               if (ret != 0) {
-                       krb5_warnx(context, "LDB_fetch: could not find principal in DB");
-                       krb5_set_error_message(context, ret, "LDB_fetch: could not find principal in DB");
-                       return ret;
-               }
-               
                ret = LDB_message2entry(context, db, mem_ctx, 
                                        principal, HDB_SAMBA4_ENT_TYPE_KRBTGT, 
                                        realm_dn, msg, entry_ex);
@@ -1238,19 +1179,38 @@ static krb5_error_code LDB_fetch_server(krb5_context context, HDB *db,
                }
                
        } else {
+               int lret;
+               char *filter = NULL;
+               const char * const *princ_attrs = user_attrs;
+               char *short_princ;
                /* server as client principal case, but we must not lookup userPrincipalNames */
-               realm_dn = ldb_get_default_basedn((struct ldb_context *)db->hdb_db);
+               realm_dn = ldb_get_default_basedn(db->hdb_db);
                realm = krb5_principal_get_realm(context, principal);
                
-               /* Check if it is our realm, otherwise give referall */
-
-               ret = LDB_lookup_principal(context, (struct ldb_context *)db->hdb_db, 
-                                          mem_ctx, 
-                                          principal, HDB_SAMBA4_ENT_TYPE_SERVER, realm_dn, &msg);
+               /* TODO: Check if it is our realm, otherwise give referall */
+               
+               ret = krb5_unparse_name_flags(context, principal,  KRB5_PRINCIPAL_UNPARSE_NO_REALM, &short_princ);
                
                if (ret != 0) {
+                       krb5_set_error_message(context, ret, "LDB_lookup_principal: could not parse principal");
+                       krb5_warnx(context, "LDB_lookup_principal: could not parse principal");
                        return ret;
                }
+               
+               lret = gendb_search_single_extended_dn(db->hdb_db, mem_ctx, 
+                                                      realm_dn, LDB_SCOPE_SUBTREE,
+                                                      &msg, princ_attrs, "(&(objectClass=user)(samAccountName=%s))", 
+                                                      ldb_binary_encode_string(mem_ctx, short_princ));
+               free(short_princ);
+               if (lret == LDB_ERR_NO_SUCH_OBJECT) {
+                       DEBUG(3, ("Failed find a entry for %s\n", filter));
+                       return HDB_ERR_NOENTRY;
+               }
+               if (lret != LDB_SUCCESS) {
+                       DEBUG(3, ("Failed single search for for %s - %s\n", 
+                                 filter, ldb_errstring(db->hdb_db)));
+                       return HDB_ERR_NOENTRY;
+               }
        }
 
        ret = LDB_message2entry(context, db, mem_ctx,