expose the client's cipher suites from the handshake (closes #23186)

Lib/ssl.py

@@ -572,6 +572,10 @@ class SSLObject:
         ssl_version, secret_bits)``."""
         return self._sslobj.cipher()
 
+    def shared_ciphers(self):
+        """Return the ciphers shared by the client during the handshake."""
+        return self._sslobj.shared_ciphers()
+
     def compression(self):
         """Return the current compression algorithm in use, or ``None`` if
         compression was not negotiated or not supported by one of the peers."""
@@ -784,6 +788,12 @@ class SSLSocket(socket):
         else:
             return self._sslobj.cipher()
 
+    def shared_ciphers(self):
+        self._checkClosed()
+        if not self._sslobj:
+            return None
+        return self._sslobj.shared_ciphers()
+
     def compression(self):
         self._checkClosed()
         if not self._sslobj: