special function for generating confirmation codes

darcs-hash:20080622163241-34904-199b3654328d78c0b9fe2fa85a3ecc1ab0b1262a.gz

1 files changed, 15 insertions, 0 deletions

diff --git a/lib/util.php b/lib/util.php
index 49349a72f..18043e867 100644
--- a/lib/util.php
+++ b/lib/util.php
@@ -927,3 +927,18 @@ function common_notice_uri(&$notice) {
 	return common_local_url('shownotice', 
 		array('notice' => $notice->id));
 }
+
+# 36 alphanums - lookalikes (0, O, 1, I) = 32 chars = 5 bits
+
+define('CODECHARS', '23456789ABCDEFGHJKLMNPQRSTUVWXYZ');
+
+function common_confirmation_code($bits) {
+	$chars = ceil($bits/5);
+	$code = '';
+	for ($i = 0; $i < $chars; $i++) {
+		# XXX: convert to string and back
+		$num = hexdec(common_good_rand(1));
+		$code .= CODECHARS[$num%32];
+	}
+	return $code;
+}