phpseclib has a variable-time HMAC comparison in SSH2::get_binary_packet() using != instead of hash_equals()
phpseclib SSH2: Variable-time comparison in HMAC verification Summary phpseclib\Net\SSH2::getbinarypacket uses PHP's != operator to compare a received SSH packet HMAC against the locally computed HMAC. != on equal-length binary strings in PHP uses memcmp, which short-circuits on the first differi...