From RFC-2831 a realm name can contain whitespace, this means using space as the delimiter for possible realms is incorrect --------------------------------------------------------------------------------------------------------------------------- Key: ELY-50 URL: https://issues.jboss.org/browse/ELY-50 Project: WildFly Elytron Issue Type: Bug Reporter: Darran Lofthouse Assignee: Darran Lofthouse Fix For: 1.0.0.Beta1 This applies to RFC 2831 (using HTTP digest as a SASL mechanism): http://tools.ietf.org/html/rfc2831 By using space as the separator a single realm name that contains a space is split into two realms. Either support quoted realm names if they contain a space or choose a different delimiter - (A different delimiter other than a control character may be difficult as the rest can appear in a realm name)