Are GET request header fields and values case-sensitive?

I'm working on a programing assignment re开发者_开发知识库garding using GET request. I am using C.

I wonder if any headers fields and values of GET packet have to be capitalized?

For example:

GET / HTTP/1.1
Connection: Keep-Alive

vs

get / HTTP/1.1
connection: keep-alive

HTTP method names are case-sensitive:

The Method token indicates the method to be performed on the resource identified by the Request-URI. The method is case-sensitive.

HTTP header names are case-insensitive.