auth: Escape LDAP search filter properly

This is syntaxical escaping to make ldap servers accept queries
with escapable characters, instead of erroring out.

diff --git a/src/auth/db-ldap.c b/src/auth/db-ldap.c
index 0194f4667861526ae9f24bc3618013d799c5c333..8c1f1b4b3c9d8e8ca5d4ddab63057de788b1bf54 100644 (file)
--- a/src/auth/db-ldap.c
+++ b/src/auth/db-ldap.c
@@ -49,6 +49,8 @@
 #  define LDAP_OPT_SUCCESS LDAP_SUCCESS
 #endif
 
+static const char *LDAP_ESCAPE_CHARS = "*,\\#+<>;\"()= ";
+
 struct db_ldap_result {
        int refcount;
        LDAPMessage *msg;
@@ -1461,31 +1463,25 @@ db_ldap_value_get_var_expand_table(struct auth_request *auth_request,
 }
 
 #define IS_LDAP_ESCAPED_CHAR(c) \
-       ((c) == '*' || (c) == '(' || (c) == ')' || (c) == '\\')
+       ((((unsigned char)(c)) & 0x80) != 0 || strchr(LDAP_ESCAPE_CHARS, (c)) != NULL)
 
 const char *ldap_escape(const char *str,
                        const struct auth_request *auth_request ATTR_UNUSED)
 {
-       const char *p;
-       string_t *ret;
+       string_t *ret = NULL;
 
-       for (p = str; *p != '\0'; p++) {
-               if (IS_LDAP_ESCAPED_CHAR(*p))
-                       break;
+       for (const char *p = str; *p != '\0'; p++) {
+               if (IS_LDAP_ESCAPED_CHAR(*p)) {
+                       if (ret == NULL) {
+                               ret = t_str_new((size_t) (p - str) + 64);
+                               str_append_n(ret, str, (size_t) (p - str));
+                       }
+                       str_printfa(ret, "\\%02X", (unsigned char)*p);
+               } else if (ret != NULL)
+                       str_append_c(ret, *p);
        }
 
-       if (*p == '\0')
-               return str;
-
-       ret = t_str_new((size_t) (p - str) + 64);
-       str_append_n(ret, str, (size_t) (p - str));
-
-       for (; *p != '\0'; p++) {
-               if (IS_LDAP_ESCAPED_CHAR(*p))
-                       str_append_c(ret, '\\');
-               str_append_c(ret, *p);
-       }
-       return str_c(ret);
+       return ret == NULL ? str : str_c(ret);
 }
 
 static bool