+ ##
+ # Verify a chain of certificates.
+ #
+ # Verification is a basic recursion: <pre>
+ # if this_certificate was signed by trusted_certs:\r
+ # return\r
+ # else\r
+ # return verify_chain(parent, trusted_certs)\r
+ # </pre>\r
+ #\r
+ # At each recursion, the parent is tested to ensure that it did sign the
+ # child. If a parent did not sign a child, then an exception is thrown. If
+ # the bottom of the recursion is reached and the certificate does not match
+ # a trusted root, then an exception is thrown.
+ #
+ # @param Trusted_certs is a list of certificates that are trusted.\r
+ #
+