Change: Set TLS minimum version, avoid version protocols

TLS connections now require TLS 1.2 as the minimum version whether
certificate files are given or not.
Also, the deprecated version specific protocol for TLS 1.2 is no
longer used.

This changes prevents possible security issues from allowing
connections with older, less secure TLS versions.

gvm/connections.py

@@ -494,8 +494,13 @@ def _new_socket(self):
  keyfile=self.keyfile,
  password=self.password,
  )
+ context.minimum_version = ssl.TLSVersion.TLSv1_2
  else:
- context = ssl.SSLContext(ssl.PROTOCOL_TLSv1_2)
+ context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
+ context.minimum_version = ssl.TLSVersion.TLSv1_2
+ context.check_hostname = False
+ context.verify_mode = ssl.CERT_NONE
+
  sock = context.wrap_socket(transport_socket, server_side=False)
 
  sock.settimeout(self._timeout)