FakeBasicAuth can produce bad HTTP userid if certificate DN contains a colon

Issue

• FakeBasicAuth can produce bad HTTP userid if certificate DN contains a colon
• I'm using mod_nss with NSSOptions +FakeBasicAuth. Client certificates are required in order to connect to my webserver (NSSVerifyClient require). So normally someone connects with a certificate having distinguished name CN=Joe, OU=Bla, O=Company, C=US, and the HTTP basic authorization username is "/CN=Joe,OU=Bla,O=Company,C=US". So far, so good. But now I have a user whose certificate DN is something like CN=Joe:A000123, OU=Bla, O=Company, C=US, i.e. it contains a colon. His HTTP basic authorization username, once FakeBasicAuth is done with its work, is "/CN=Joe", i.e. the username is truncated before the colon. Then he can't get in, because my database doesn't contain any users named solely "/CN=Joe".