# IO::Socket::Async::SSL [![Build Status](https://travis-ci.org/jnthn/p6-io-socket-async-ssl.svg?branch=master)](https://travis-ci.org/jnthn/p6-io-socket-async-ssl) This module provides a secure sockets implementation with an API very much like that of the Perl 6 built-in `IO::Socket::Async` class. For the client case, provided the standard certificate and host verification are sufficient, it is drop-in replacement. The server case only needs two extra arguments to `listen`, specifying the server key and certificate. As with `IO::Socket::Async`, it is safe to have concurrent connections and to share them across threads. ## Synopsis Client: use IO::Socket::Async::SSL; my $conn = await IO::Socket::Async::SSL.connect('www.perl6.org', 443); $conn.print: "GET / HTTP/1.0\r\nHost: www.perl6.org\r\n\r\n"; react { whenever $conn { .print } } $conn.close; Server (assumes certificate and key files `server-crt.pem` and `server-key.pem`): use IO::Socket::Async::SSL; react { my %ssl-config = certificate-file => 'server-crt.pem', private-key-file => 'server-key.pem'; whenever IO::Socket::Async::SSL.listen('localhost', 4433, |%ssl-config) -> $conn { my $req = ''; whenever $conn { $req ~= $_; if $req.contains("\r\n\r\n") { say $req.lines[0]; await $conn.print( "HTTP/1.0 200 OK\r\nContent-type: text/html\r\n\r\n" ~ "Hello from a Perl 6 HTTP server\n"); $conn.close; } } } } ## Client The `connect` method on `IO::Socket::Async::SSL` is used to establish a SSL connection to a server. It requies two positional arguments, which specify the `host` and `port` to connect to. It returns a `Promise`, which will be kept with an `IO::Socket::Async::SSL` instance when the connection is established and the SSL handshake completed. my $conn = await IO::Socket::Async::SSL.connect($host, $port); By default, the SSL certificate will be verified, using the default set of accepted Certificate Authorities. The `Promise` return by `conenct` will be broken if verification fails. Sometimes it is convenient to create a CA and use it to sign certificates for internal use, for example to secure communications between a set of services on an internal network. In this case, the `ca-file` named argument can be passed to specify the certificate authority certificate file: my $ca-file = '/config/ca-crt.pem'; my $conn = await IO::Socket::Async::SSL.connect('user-service', 443, :$ca-file); Alternatively, a `ca-path` argument can be specified, indicating a directory where one or more certificates may be found. It is possible to disable certificate verification by passing the `insecure` named argument a true value. As the name suggests, **this is not a secure configuration**, since there is no way for the client to be sure that it is communicating with the intended server. Therefore, it is vulnerable to man-in-the-middle attacks. ## Server The `listen` method returns a `Supply` that, when tapped, will start an SSL server. The server can be shut down by closing the tap. Whenever a connection is made to the server, the `Supply` will emit an `IO::Socket::Async::SSL` instance. The `listen` method requires two positional arguments, specifying the `host` and `port` to listen on. Two named arguments are also required, providing the `certificate-file` and `private-key-file`. my %ssl-config = certificate-file => 'server-crt.pem', private-key-file => 'server-key.pem'; my $connections = IO::Socket::Async::SSL.listen('localhost', 4433, |%ssl-config); react { my $listener = do whenever $connections -> $conn { say "Got a connection!"; $conn.close; } whenever signal(SIGINT) { say "Shutting down..."; $listener.close; exit; } } ## Common client and server functionality Both the `connect` and `listen` methods take the following optional named arguments: * `enc`, which specifies the encoding to use when the socket is used in character mode. Defaults to `utf-8`. * `scheduler`, which specifies the scheduler to use for processing events from the underlying `IO::Socket::Async` instance. The default is `$*SCHEDULER`. There is rarely a need to change this. The `Supply`, `print`, `write`, and `close` methods have the same semantics as in [IO::Socket::Async](https://docs.perl6.org/type/IO$COLON$COLONSocket$COLON$COLONAsync). ## Bugs, feature requests, and contributions Please use GitHub Issues to file bug reports and feature requests. If you wish to contribute to this module, please file a GitHub Pull Request, or email a Git patch (produced using `format-patch`) to [jnthn@jnthn.net](mailto:jnthn@jnthn.net).