Prevent use of an invalid salt for Blowfish hashing of passwords

src/mibew/libs/operator.php

@@ -837,9 +837,9 @@ function calculate_password_hash($login, $password)
     $hash = '*0';
     if (CRYPT_BLOWFISH == 1) {
         if (defined('PHP_VERSION_ID') && (PHP_VERSION_ID > 50306)) {
-            $hash = crypt($password, '$2y$08$' . $login);
+            $hash = crypt($password, '$2y$08$' . generate_bf_salt($login));
         } else {
-            $hash = crypt($password, '$2a$08$' . $login);
+            $hash = crypt($password, '$2a$08$' . generate_bf_salt($login));
         }
     }
 
@@ -850,6 +850,61 @@ function calculate_password_hash($login, $password)
     return strcmp($hash, '*0') ? $hash : md5($password);
 }
 
+/**
+ * Generates correct blowfish salt based a string.
+ *
+ * @param string $string A string which should be turned to blowfish salt.
+ * @return string Correct blowfish salt.
+ */
+function generate_bf_salt($string)
+{
+    $result = '';
+    $bin = unpack('C*', md5($string, true));
+    for ($i = 0; $i < count($bin); $i++) {
+        $shift = 2 + ($i % 3) * 2;
+        $first = ($bin[$i + 1] >> $shift);
+        $second = ($bin[$i + 1] & bindec(str_repeat('1', $shift)));
+        switch ($shift) {
+            case 2:
+                $result .= bf_salt_character($first);
+                $tmp = $second;
+                break;
+            case 4:
+                $result .= bf_salt_character(($tmp << 4) | $first);
+                $tmp = $second;
+                break;
+            case 6:
+                $result .= bf_salt_character(($tmp << 2) | $first);
+                $result .= bf_salt_character($second);
+                break;
+        }
+    }
+    if ($shift == 2) {
+        $result .= bf_salt_character($second);
+    }
+
+    return $result;
+}
+
+/**
+ * Convert character code to a correct blowfish character.
+ *
+ * @param integer $num Character code.
+ * @return string Character that can be used in blowfish salt.
+ */
+function bf_salt_character($num)
+{
+    if ($num > 63) {
+        return chr(46);
+    } elseif ($num < 12) {
+        return chr(46 + $num);
+    } elseif ($num < 38) {
+        return chr(53 + $num);
+    } else {
+        return chr(59 + $num);
+    }
+}
+
 /**
  * Validate incoming hashed value to be the hashed value of operator's password
  *