MODIFIED: Remove TLS-related predicates from library(sockets).

They will become available in a new library, library(tls).

README.md

@@ -537,10 +537,6 @@ The modules that ship with Scryer Prolog are also called
   is often used together with [`library(sgml)`](src/lib/sgml.pl).
 * [`sockets`](src/lib/sockets.pl)
   Predicates for opening and accepting TCP connections as streams.
-  TLS negotiation is performed via the option `tls(true)` in
-  `socket_client_open/3`, yielding secure encrypted connections.
-  TLS *servers* can be created with `tls_server_context/2` and
-  `tls_server_negotiate/3`.
 * [`os`](src/lib/os.pl)
   Predicates for reasoning about environment variables.
 * [`iso_ext`](src/lib/iso_ext.pl)

src/clause_types.rs

@@ -742,7 +742,7 @@ impl SystemClauseType {
             ("$set_seed", 1) => Some(SystemClauseType::SetSeed),
             ("$skip_max_list", 4) => Some(SystemClauseType::SkipMaxList),
             ("$sleep", 1) => Some(SystemClauseType::Sleep),
-            ("$socket_client_open", 8) => Some(SystemClauseType::SocketClientOpen),
+            ("$socket_client_open", 7) => Some(SystemClauseType::SocketClientOpen),
             ("$socket_server_open", 3) => Some(SystemClauseType::SocketServerOpen),
             ("$socket_server_accept", 7) => Some(SystemClauseType::SocketServerAccept),
             ("$socket_server_close", 1) => Some(SystemClauseType::SocketServerClose),

src/lib/sockets.pl

@@ -3,24 +3,9 @@
                     socket_server_open/2,
                     socket_server_accept/4,
                     socket_server_close/1,
-                    tls_server_context/2,       % tls_server_context(-Context, +Options)
-                    tls_server_negotiate/3,     % tls_server_negotiate(+Context, +Stream0, -Stream)
                     current_hostname/1]).
 
 :- use_module(library(error)).
-:- use_module(library(lists)).
-
-% a client can negotiate a TLS connection by specifying the option
-% tls(true) in socket_client_open/3
-
-parse_socket_options_(tls(TLS), tls-TLS) :-
-    must_be(boolean, TLS), !.
-parse_socket_options_(Option, OptionPair) :-
-    builtins:parse_stream_options_(Option, OptionPair).
-
-parse_socket_options(Options, OptionValues, Stub) :-
-    DefaultOptions = [alias-[], eof_action-eof_code, reposition-false, tls-false, type-text],
-    builtins:parse_options_list(Options, sockets:parse_socket_options_, DefaultOptions, OptionValues, Stub).
 
 socket_client_open(Addr, Stream, Options) :-
     (  var(Addr) ->
@@ -37,10 +22,10 @@ socket_client_open(Addr, Stream, Options) :-
     ;
        throw(error(type_error(socket_address, Addr), socket_client_open/3))
     ),
-    parse_socket_options(Options,
+    builtins:parse_stream_options(Options,
-                         [Alias, EOFAction, Reposition, TLS, Type],
+                                  [Alias, EOFAction, Reposition, Type],
-                         socket_client_open/3),
+                                  socket_client_open/3),
-    '$socket_client_open'(Address, Port, Stream, Alias, EOFAction, Reposition, Type, TLS).
+    '$socket_client_open'(Address, Port, Stream, Alias, EOFAction, Reposition, Type).
 
 
 socket_server_open(Addr, ServerSocket) :-
@@ -70,65 +55,3 @@ socket_server_close(ServerSocket) :-
 
 current_hostname(HostName) :-
     '$current_hostname'(HostName).
-
-/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-   TLS Servers
-   ===========
-
-   Use tls_server_context/2 to create a TLS context, for example with:
-
-   tls_server_context(Context, [pkcs12(Chars)])
-
-   where Chars is a list of characters with the contents of a
-   DER-formatted PKCS #12 archive. The option password(Ps) can be used
-   to specify the password Ps (also a string) for decrypting the key.
-   On some versions of OSX, and potentially also on other platforms,
-   empty passwords are not supported.
-
-   The archive should contain a leaf certificate and its private key,
-   as well any intermediate certificates that should be sent to
-   clients to allow them to build a chain to a trusted root. The chain
-   certificates should be in order from the leaf certificate towards
-   the root.
-
-   PKCS #12 archives typically have the file extension .p12 or .pfx,
-   and can be created with the OpenSSL pkcs12 tool:
-
-   $ openssl pkcs12 -export -out identity.pfx \
-                    -inkey key.pem -in cert.pem -certfile chain_certs.pem
-
-
-   You can use phrase_from_file/3 from library(pio) and seq//1 from
-   library(dcgs) to read the contents of "identity.pfx" into a string:
-
-   phrase_from_file(seq(Chars), "identity.pfx", [type(binary)])
-
-   The obtained context should be treated as an opaque Prolog term.
-
-   Using the context and an existing stream S0 (for example, the
-   result of socket_server_accept/4), a TLS stream S can be negotiated
-   by a Prolog-based server with:
-
-   tls_server_negotiate(Context, S0, S)
-
-   S will be an encrypted and authenticated stream with the client.
-
-   The advantage of separating the creation of the server context from
-   negotiating a connection is that the context can be created only
-   once, and quickly cloned for every incoming connection. This is
-   currently not implemented: In the present implementation, a new context
-   is created for every connection, using the specified parameters.
-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
-
-tls_server_context(tls_context(Cert,Password), Options) :-
-        (   member(pcks12(Cert), Options) ->
-            must_be(chars, Cert)
-        ;   domain_error(contains_pcks12, Options, tls_server_context/2)
-        ),
-        (   member(password(Password), Options) ->
-            must_be(chars, Password)
-        ;   Password = ""
-        ).
-
-tls_server_negotiate(tls_context(Cert,Password), S0, S) :-
-        '$tls_accept_client'(Cert, Password, S0, S).