Rust wrapper for xmlsec1

This library aims at wrapping xmlsec1 and being interoperable with rust-libxml, while attemting to be as correct and comfortable to use as possible.

Things needing improvement

• Better input sanitization of string arguments. Currently they get blindly turned into a FFI version and passed through to xmlsec.
• Proper management for xmlsec error handling. Currently things fail very opaquely without actually telling you why the signing process failed, just that it failed for the particular job.
• More expressive error handling chain.

Things not yet supported

• XML encryption.
• Key management (as in xmlsec key manager). Though the value of wrapping that should be debated first. It may be more sensible to lift that to pure Rust instead.
• Dynamic selection of crypto backend.

Contibuting

Help in any way improving or completing the wrapping of xmlsec features always very welcome! Please keep some things in mind before PR'ing your changes;

• Please check tests for breakage and write new ones to cover your changes.
• Please run valgrind over your tests and make sure you are not leaking resources.

Tested platforms

• Debian Buster (10.x)