Add PCRE_DOLLAR_ENDONLY to preg_match()

When using preg_match() to check for a match that starts at the
beginning of the string and ends at the last character of the string, we
do not want to allow an additional newline character to sneak in.
Amongst other potential loopholes, adding the PCRE_DOLLAR_ENDONLY
modifier prevents users from registering with user names that end with a
newline character.

Signed-off-by: Lukas Fleischer <archlinux@cryptocrack.de>

1 files changed, 1 insertions, 1 deletions

diff --git a/web/lib/acctfuncs.inc.php b/web/lib/acctfuncs.inc.php
index 254f0e2f..e3ff4949 100644
--- a/web/lib/acctfuncs.inc.php
+++ b/web/lib/acctfuncs.inc.php
@@ -544,7 +544,7 @@ function valid_username($user) {
 	if (strlen($user) < USERNAME_MIN_LEN ||
 	    strlen($user) > USERNAME_MAX_LEN) {
 		return false;
-	} else if (!preg_match("/^[a-z0-9]+[.\-_]?[a-z0-9]+$/i", $user)) {
+	} else if (!preg_match("/^[a-z0-9]+[.\-_]?[a-z0-9]+$/Di", $user)) {
 		return false;
 	}