Change the server to reject invalidly-encoded multibyte characters in all cases (Tatsuo, Tom)

While PostgreSQL has been moving in this direction for some time, the checks are now applied uniformly to all encodings and all textual input, and are now always errors not merely warnings. This change defends against SQL-injection attacks of the type described in CVE-2006-2313.

Reject unsafe uses of \' in string literals

As a server-side defense against SQL-injection attacks of the type described in CVE-2006-2314, the server now only accepts '' and not \' as a representation of ASCII single quote in SQL string literals. By default, \' is rejected only when client_encoding is set to a client-only encoding (SJIS, BIG5, GBK, GB18030, or UHC), which is the scenario in which SQL injection is possible. A new configuration parameter backslash_quote is available to adjust this behavior when needed. Note that full security against CVE-2006-2314 might require client-side changes; the purpose of backslash_quote is in part to make it obvious that insecure clients are insecure.

Modify libpq's string-escaping routines to be aware of encoding considerations

This fixes libpq-using applications for the security issues described in CVE-2006-2313 and CVE-2006-2314. Applications that use multiple PostgreSQL connections concurrently should migrate to PQescapeStringConn() and PQescapeByteaConn() to ensure that escaping is done correctly for the settings in use in each database connection. Applications that do string escaping “by hand” should be modified to rely on library routines instead.

Fix some incorrect encoding conversion functions

win1251_to_iso, alt_to_iso, euc_tw_to_big5, euc_tw_to_mic, mic_to_euc_tw were all broken to varying extents.

Clean up stray remaining uses of \' in strings (Bruce, Jan)

Fix server to use custom DH SSL parameters correctly (Michael Fuhr)

Fix various minor memory leaks