• SFTP: don't check SFTP packet size after SFTP initialization (#1606)
• SFTP: timeout during SFTP init should return false (#1684)
• SFTP: return false if get_channel_packet returns false (#1678)
• ASN1: return false when not enough bytes are available (#1676)
• BigInteger: Serializable is being deprecated in PHP 8.1 (#1680)
• explicitly define methods as being static (#1689)
• plug memory leaks (#1672)