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module JSONWebToken
class RSAToken < Token
attr_reader :key_file
def initialize(key_file)
super()
@key_file = key_file
end
def encoded
headers = {
kid: kid
}
JWT.encode(payload, key, 'RS256', headers)
end
private
def key_data
@key_data ||= File.read(key_file)
end
def key
@key ||= OpenSSL::PKey::RSA.new(key_data)
end
def public_key
key.public_key
end
def kid
# calculate sha256 from DER encoded ASN1
kid = Digest::SHA256.digest(public_key.to_der)
# we encode only 30 bytes with base32
kid = Base32.encode(kid[0..29])
# insert colon every 4 characters
kid.scan(/.{4}/).join(':')
end
end
end