Create a signature (Akamai OPEN API)

sign.rb

SIGNING_ALGORITHM = 'EG1-HMAC-SHA256'

def create_auth_header(method, scheme, host, path, headers, payload = nil, _timestamp = nil, _nonce = nil)
  timestamp = _timestamp.nil? ? Time.now.gmtime.strftime('%Y%m%dT%H:%M:%S%z') : _timestamp
  nonce = _nonce.nil? ? UUIDTools::UUID.random_create.to_s : _nonce

  signing_key = Base64.encode64(OpenSSL::HMAC::digest(OpenSSL::Digest::SHA256.new, @secret, timestamp)).strip

  authorization_header = SIGNING_ALGORITHM + ' '
  authorization_header << "client_token=#{@client_token};"
  authorization_header << "access_token=#{@access_token};"
  authorization_header << "timestamp=#{timestamp};"
  authorization_header << "nonce=#{nonce};"

  payload_digest = nil
  payload_digest = Base64.encode64(OpenSSL::Digest::SHA256.digest(payload)).strip unless payload.nil?

  data = [method.upcase, scheme.downcase, host.downcase, path, headers, payload_digest, authorization_header].join("\t")

  signature = Base64.encode64(OpenSSL::HMAC::digest(OpenSSL::Digest::SHA256.new, signing_key, data)).strip

  authorization_header << "signature=#{signature}"

  authorization_header
end