openssl: repairs related to listen on port number 0

Allow 0 as the port number in `ssl-listen`, and fix
`ssl-addresses` to work on a listener. Update a test
to use these features so that it won't conflict with
other tests that listen on TCP addresses.

pkgs/racket-doc/openssl/openssl.scrbl

@@ -265,7 +265,7 @@ current platform for client connections.
 @section{TCP-like Server Procedures}
 
 @defproc[(ssl-listen
-	  [port-no (integer-in 1 65535)]
+	  [port-no listen-port-number?]
 	  [queue-k exact-nonnegative-integer? 5]
 	  [reuse? any/c #f]
 	  [hostname-or-#f (or/c string? #f) #f]

pkgs/racket-test/tests/openssl/peer-verif.rkt

@@ -30,12 +30,17 @@
      ssl-server-context 
      #t))
 
-  (define ssl-listener (ssl-listen 55000
+  (define ssl-listener (ssl-listen 0
                                    4
                                    #t
                                    "127.0.0.1"
                                    ssl-server-context))
 
+  (define port-number (let ()
+                        (define-values (addr port-number other-addr other-port-number)
+                          (ssl-addresses ssl-listener #t))
+                        port-number))
+
   (define listener-main 
     (thread 
      (lambda()
@@ -91,7 +96,7 @@
     (ssl-set-verify! ssl-client-context #t))
 
   (let-values ([(in out) (ssl-connect "127.0.0.1"
-                                      55000
+                                      port-number
                                       ssl-client-context)])
     (check "Client: Made connection.~n" #t #t)
     (when later-mode

racket/collects/openssl/mzssl.rkt

@@ -172,7 +172,7 @@ TO DO:
          #:hostname (or/c string? #f)]
         (values input-port? output-port?))]
   [ssl-listen
-   (->* [(integer-in 1 (sub1 (expt 2 16)))]
+   (->* [listen-port-number?]
         [exact-nonnegative-integer?
          any/c
          (or/c string? #f)
@@ -1545,7 +1545,8 @@ TO DO:
       (if (eq? 'listener input?)
           (ssl-listener-l mzssl)
           (if input? (mzssl-i mzssl) (mzssl-o mzssl))))
-    (cond [(tcp-port? port) (tcp-addresses port port-numbers?)]
+    (cond [(or (tcp-port? port) (tcp-listener? port))
+           (tcp-addresses port port-numbers?)]
           [else (error 'ssl-addresses "not connected to TCP port")])))
 
 (define (ssl-abandon-port p)