# File lib/aws/ec2/client.rb, line 22 def sign_request request version = @config.ec2_signature_version ? @config.ec2_signature_version.to_sym : (@region =~ /cn-/ ? :v4 : :v2) case version when :v4 then v4_signer.sign_request(request) when :v2 then v2_signer.sign_request(request) else raise "invalid signature version #{version.inspect}" end end