XML-Security-C is the C++ XML Signature and Encryption library from the Apache Software Foundation. It is used for all XML Signature and Encryption processing in OpenSAML and Shibboleth.
Project Website: http://xml.apache.org/security/c/
For now, build notes can be found in the BuildingShibboleth topic.
The above site is now offering version 1.3.1, with version 1.3 becoming available in August 2006...
Note that version 1.3, required by OpenSAML 2 (C++ Edition), is not yet officially released, but will be at some point. The code is publically available in the Apache svn trunk:
http://svn.apache.org/repos/asf/xml/security/trunk/c
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