From Dan: Reserved words from JWS (JSON Web Signatures) spec

[Drummond Reed <drummond.reed@xdi.org>]

Dan extracted this set of reserved words from http://tools.ietf.org/html/draft-ietf-jose-json-web-signature-17.

This will help us analyze what XDI keywords we may need for crypto metadata.

4.1.1.  "alg" (Algorithm) Header Parameter

4.1.2.  "jku" (JWK Set URL) Header Parameter

4.1.3.  "jwk" (JSON Web Key) Header Parameter 

4.1.4.  "x5u" (X.509 URL) Header Parameter

4.1.5.  "x5t" (X.509 Certificate SHA-1 Thumbprint) Header Parameter 

4.1.6.  "x5c" (X.509 Certificate Chain) Header Parameter

4.1.7.  "kid" (Key ID) Header Parameter 

4.1.8.  "typ" (Type) Header Parameter 

4.1.9.  "cty" (Content Type) Header Parameter

4.1.10. "crit" (Critical) Header Parameter