python: rewrite comment

Author: yoff

python/ql/src/Security/CWE-327/FluentApiModel.qll

@@ -4,21 +4,16 @@ import TlsLibraryModel
 
 /**
  * Configuration to determine the state of a context being used to create
- * a connection. There is one configuration for each pair of `TlsLibrary` and `ProtocolVersion`,
- * such that a single configuration only tracks contexts where a specific `ProtocolVersion` is allowed.
+ * a connection. The configuration uses a flow state to track the `TlsLibrary`
+ * and the insecure `ProtocolVersion`s that are allowed.
  *
  * The state is in terms of whether a specific protocol is allowed. This is
  * either true or false when the context is created and can then be modified
- * later by either restricting or unrestricting the protocol (see the predicates
- * `isRestriction` and `isUnrestriction`).
+ * later by either restricting or unrestricting the protocol (see the predicate
+ * `isAdditionalFlowStep`).
  *
- * Since we are interested in the final state, we want the flow to start from
- * the last unrestriction, so we disallow flow into unrestrictions. We also
- * model the creation as an unrestriction of everything it allows, to account
- * for the common case where the creation plays the role of "last unrestriction".
- *
- * Since we really want "the last unrestriction, not nullified by a restriction",
- * we also disallow flow into restrictions.
+ * The state is represented as a bit vector, where each bit corresponds to a
+ * protocol version. The bit is set if the protocol is allowed.
  */
 module InsecureContextConfiguration implements DataFlow::StateConfigSig {
   private newtype TFlowState =