Tomasz Ostrowski wrote: > On Sun, 23 Dec 2007, Tom Lane wrote: > > > ISTM we have these action items: > > 1. Improve the code so that SSL authentication can be used across a > > Unix-socket connection (we can disable encryption though). > > I've just realised that there's a problem with SSL with disabled > encryption on a unix socket / localhost connections for cpu-saving. > Any local user using this attack would be able to eavesdrop > everything comming through a socket. > > If an attacker just acts as a tunnel, highjacking a unix-socket and > talking to a server using any other interface (or the other way > around), then he would not be able to modify information flow, but he > would be able to read and save everything going to and from a server. > It is again not obvious as normally local connections are not > susceptible to eavesdropping. And could go unnoticed for a long time > as everything would just work normally. > > So I think no cpu-saving by turning off encryption should be done. > > And this would all not help for a denial-of-service attack.
Good point. I have added the last two sentences to the documentation paragraph to highlight this issue: <productname>OpenSSL</productname> supports a wide range of ciphers and authentication algorithms, of varying strength. While a list of ciphers can be specified in the <productname>OpenSSL</productname> configuration file, you can specify ciphers specifically for use by the database server by modifying <xref linkend="guc-ssl-ciphers"> in <filename>postgresql.conf</>. It is possible to have authentication without the overhead of encryption by using <literal>NULL-SHA</> or <literal>NULL-MD5</> ciphers. However, a man-in-the-middle could read and pass communications between client and server. -- Bruce Momjian <[EMAIL PROTECTED]> http://momjian.us EnterpriseDB http://postgres.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
