Major NonceManager of HTTP DIGEST mechanism requires nonce to base64 encoded value, otherwise it fails on DecodeException.
In RFC there is no requirement for client to use base64 value as cnonce. There is only recommendation for server nonce:
nonce
A server-specified data string which MUST be different each time a
digest-challenge is sent as part of initial authentication. It is
recommended that this string be base64 or hexadecimal data.
