*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/interfaces/libpq/fe-secure.c,v 1.105 2008/05/16 18:30:53 mha Exp $
+ * $PostgreSQL: pgsql/src/interfaces/libpq/fe-secure.c,v 1.106 2008/10/24 12:29:11 mha Exp $
*
* NOTES
- * [ Most of these notes are wrong/obsolete, but perhaps not all ]
- *
- * The client *requires* a valid server certificate. Since
- * SSH tunnels provide anonymous confidentiality, the presumption
- * is that sites that want endpoint authentication will use the
- * direct SSL support, while sites that are comfortable with
- * anonymous connections will use SSH tunnels.
- *
- * This code verifies the server certificate, to detect simple
- * "man-in-the-middle" and "impersonation" attacks. The
- * server certificate, or better yet the CA certificate used
- * to sign the server certificate, should be present in the
- * "~/.postgresql/root.crt" file. If this file isn't
- * readable, or the server certificate can't be validated,
- * pqsecure_open_client() will return an error code.
- *
- * Additionally, the server certificate's "common name" must
- * resolve to the other end of the socket. This makes it
- * substantially harder to pull off a "man-in-the-middle" or
- * "impersonation" attack even if the server's private key
- * has been stolen. This check limits acceptable network
- * layers to Unix sockets (weird, but legal), TCPv4 and TCPv6.
- *
- * Unfortunately neither the current front- or back-end handle
- * failure gracefully, resulting in the backend hiccupping.
- * This points out problems in each (the frontend shouldn't even
- * try to do SSL if pqsecure_initialize() fails, and the backend
- * shouldn't crash/recover if an SSH negotiation fails. The
- * backend definitely needs to be fixed, to prevent a "denial
- * of service" attack, but I don't know enough about how the
- * backend works (especially that pre-SSL negotiation) to identify
- * a fix.
- *
- * ...
- *
- * Unlike the server's static private key, the client's
- * static private key (~/.postgresql/postgresql.key)
- * should normally be stored encrypted. However we still
- * support EPH since it's useful for other reasons.
- *
- * ...
- *
- * Client certificates are supported, if the server requests
- * or requires them. Client certificates can be used for
- * authentication, to prevent sessions from being hijacked,
- * or to allow "road warriors" to access the database while
- * keeping it closed to everyone else.
- *
- * The user's certificate and private key are located in
- * ~/.postgresql/postgresql.crt
- * and
- * ~/.postgresql/postgresql.key
- * respectively.
- *
- * ...
*
* We don't provide informational callbacks here (like
* info_cb() in be-secure.c), since there's mechanism to