According to http://tools.ietf.org/html/rfc7230#section-3.2.6 the pipe symbol (|) is a legal header character, whereas the comma (,) is not.
According to http://tools.ietf.org/html/rfc7230#section-3.2.6
the pipe symbol (|) is a legal header character, whereas
the comma (,) is not.

1ma/Psr7Hmac