Introduce cowboy_req:sock/1 and cowboy_req:cert/1

To obtain the local socket ip/port and the client TLS
certificate, respectively.

doc/src/manual/cowboy_req.asciidoc

@@ -29,6 +29,12 @@ and to read the body once.
 
 == Exports
 
+Connection:
+
+* link:man:cowboy_req:peer(3)[cowboy_req:peer(3)] - Peer address and port
+* link:man:cowboy_req:sock(3)[cowboy_req:sock(3)] - Socket address and port
+* link:man:cowboy_req:cert(3)[cowboy_req:cert(3)] - Client TLS certificate
+
 Raw request:
 
 * link:man:cowboy_req:method(3)[cowboy_req:method(3)] - HTTP method
@@ -41,7 +47,6 @@ Raw request:
 * link:man:cowboy_req:uri(3)[cowboy_req:uri(3)] - Reconstructed URI
 * link:man:cowboy_req:header(3)[cowboy_req:header(3)] - HTTP header
 * link:man:cowboy_req:headers(3)[cowboy_req:headers(3)] - HTTP headers
-* link:man:cowboy_req:peer(3)[cowboy_req:peer(3)] - Peer address and port
 
 Processed request:
 
@@ -129,7 +134,9 @@ req() :: #{
     path    := binary(),               %% case sensitive
     qs      := binary(),               %% case sensitive
     headers := cowboy:http_headers(),
-    peer    := {inet:ip_address(), inet:port_number()}
+    peer    := {inet:ip_address(), inet:port_number()},
+    sock    := {inet:ip_address(), inet:port_number()},
+    cert    := binary() | undefined
 }
 ----
 

doc/src/manual/cowboy_req.cert.asciidoc

@@ -0,0 +1,71 @@
+= cowboy_req:cert(3)
+
+== Name
+
+cowboy_req:cert - Client TLS certificate
+
+== Description
+
+[source,erlang]
+----
+cert(Req :: cowboy_req:req()) -> binary() | undefined
+----
+
+Return the peer's TLS certificate.
+
+Using the default configuration this function will always return
+`undefined`. You need to explicitly configure Cowboy to request
+the client certificate. To do this you need to set the `verify`
+transport option to `verify_peer`:
+
+[source,erlang]
+----
+{ok, _} = cowboy:start_tls(example, [
+    {port, 8443},
+    {cert, "path/to/cert.pem"},
+    {verify, verify_peer}
+], #{
+    env => #{dispatch => Dispatch}
+}).
+----
+
+You may also want to customize the `verify_fun` function. Please
+consult the `ssl` application's manual for more details.
+
+TCP connections do not allow a certificate and this function
+will therefore always return `undefined`.
+
+The certificate can also be obtained using pattern matching:
+
+[source,erlang]
+----
+#{cert := Cert} = Req.
+----
+
+== Arguments
+
+Req::
+
+The Req object.
+
+== Return value
+
+The client TLS certificate.
+
+== Changelog
+
+* *2.0*: Function introduced.
+
+== Examples
+
+.Get the client TLS certificate.
+[source,erlang]
+----
+Cert = cowboy_req:cert(Req).
+----
+
+== See also
+
+link:man:cowboy_req(3)[cowboy_req(3)],
+link:man:cowboy_req:peer(3)[cowboy_req:peer(3)],
+link:man:cowboy_req:sock(3)[cowboy_req:sock(3)]

doc/src/manual/cowboy_req.peer.asciidoc

@@ -8,14 +8,14 @@ cowboy_req:peer - Peer address and port
 
 [source,erlang]
 ----
-peer(Req :: cowboy_req:req()) -> Peer
+peer(Req :: cowboy_req:req()) -> Info
 
-Peer :: {inet:ip_address(), inet:port_number()}
+Info :: {inet:ip_address(), inet:port_number()}
 ----
 
 Return the peer's IP address and port number.
 
-The peer can also be obtained using pattern matching:
+The peer information can also be obtained using pattern matching:
 
 [source,erlang]
 ----
@@ -56,4 +56,6 @@ way of determining the source of an HTTP request.
 
 == See also
 
-link:man:cowboy_req(3)[cowboy_req(3)]
+link:man:cowboy_req(3)[cowboy_req(3)],
+link:man:cowboy_req:sock(3)[cowboy_req:sock(3)],
+link:man:cowboy_req:cert(3)[cowboy_req:cert(3)]

doc/src/manual/cowboy_req.sock.asciidoc

@@ -0,0 +1,51 @@
+= cowboy_req:sock(3)
+
+== Name
+
+cowboy_req:sock - Socket address and port
+
+== Description
+
+[source,erlang]
+----
+sock(Req :: cowboy_req:req()) -> Info
+
+Info :: {inet:ip_address(), inet:port_number()}
+----
+
+Return the socket's IP address and port number.
+
+The socket information can also be obtained using pattern matching:
+
+[source,erlang]
+----
+#{sock := {IP, Port}} = Req.
+----
+
+== Arguments
+
+Req::
+
+The Req object.
+
+== Return value
+
+The socket's local IP address and port number.
+
+== Changelog
+
+* *2.0*: Function introduced.
+
+== Examples
+
+.Get the socket's IP address and port number.
+[source,erlang]
+----
+{IP, Port} = cowboy_req:sock(Req).
+----
+
+== See also
+
+link:man:cowboy_req(3)[cowboy_req(3)],
+link:man:cowboy_req:peer(3)[cowboy_req:peer(3)],
+link:man:cowboy_req:cert(3)[cowboy_req:cert(3)]