class Cie::Saml::Utils

SAML2 Auxiliary class

Constants

DSIG
XENC

Public Class Methods

build_query(params) click to toggle source

Build the Query String signature that will be used in the HTTP-Redirect binding to generate the Signature @param params [Hash] Parameters to build the Query String @option params [String] :type 'SAMLRequest' or 'SAMLResponse' @option params [String] :data Base64 encoded SAMLRequest or SAMLResponse @option params [String] :relay_state The RelayState parameter @option params [String] :sig_alg The SigAlg parameter @return [String] The Query String

# File lib/cie/ruby-saml/utils.rb, line 62
def self.build_query(params)
  type, data, relay_state, sig_alg = [:type, :data, :relay_state, :sig_alg].map { |k| params[k]}

  url_string = "#{type}=#{CGI.escape(data)}"
  url_string << "&RelayState=#{CGI.escape(relay_state)}" if relay_state
  url_string << "&SigAlg=#{CGI.escape(sig_alg)}"
end
decrypt_data(encrypted_node, private_key) click to toggle source

Obtains the decrypted string from an Encrypted node element in XML @param encrypted_node [REXML::Element] The Encrypted element @param private_key [OpenSSL::PKey::RSA] The Service provider private key @return [String] The decrypted data

# File lib/cie/ruby-saml/utils.rb, line 105
def self.decrypt_data(encrypted_node, private_key)
  encrypt_data = REXML::XPath.first(
    encrypted_node,
    "./xenc:EncryptedData",
    { 'xenc' => XENC }
  )
  symmetric_key = retrieve_symmetric_key(encrypt_data, private_key)
  cipher_value = REXML::XPath.first(
    encrypt_data,
    "//xenc:EncryptedData/xenc:CipherData/xenc:CipherValue",
    { 'xenc' => XENC }
  )
  node = Base64.decode64(cipher_value.text)
  encrypt_method = REXML::XPath.first(
    encrypt_data,
    "//xenc:EncryptedData/xenc:EncryptionMethod",
    { 'xenc' => XENC }
  )
  algorithm = encrypt_method.attributes['Algorithm']
  retrieve_plaintext(node, symmetric_key, algorithm)
end
element_text(element) click to toggle source

Given a REXML::Element instance, return the concatenation of all child text nodes. Assumes that there all children other than text nodes can be ignored (e.g. comments). If nil is passed, nil will be returned.

# File lib/cie/ruby-saml/utils.rb, line 218
def self.element_text(element)
  element.texts.map(&:value).join if element
end
format_cert(cert) click to toggle source

Return a properly formatted x509 certificate

@param cert [String] The original certificate @return [String] The formatted certificate

# File lib/cie/ruby-saml/utils.rb, line 23
def self.format_cert(cert)
  # don't try to format an encoded certificate or if is empty or nil
  return cert if cert.nil? || cert.empty? || cert.match(/\x0d/)

  cert = cert.gsub(/\-{5}\s?(BEGIN|END) CERTIFICATE\s?\-{5}/, "")
  cert = cert.gsub(/[\n\r\s]/, "")
  cert = cert.scan(/.{1,64}/)
  cert = cert.join("\n")
  "-----BEGIN CERTIFICATE-----\n#{cert}\n-----END CERTIFICATE-----"
end
format_private_key(key) click to toggle source

Return a properly formatted private key

@param key [String] The original private key @return [String] The formatted private key

# File lib/cie/ruby-saml/utils.rb, line 39
def self.format_private_key(key)
  # don't try to format an encoded private key or if is empty
  return key if key.nil? || key.empty? || key.match(/\x0d/)

  # is this an rsa key?
  rsa_key = key.match("RSA PRIVATE KEY")
  key = key.gsub(/\-{5}\s?(BEGIN|END)( RSA)? PRIVATE KEY\s?\-{5}/, "")
  key = key.gsub(/[\n\r\s]/, "")
  key = key.scan(/.{1,64}/)
  key = key.join("\n")
  key_label = rsa_key ? "RSA PRIVATE KEY" : "PRIVATE KEY"
  "-----BEGIN #{key_label}-----\n#{key}\n-----END #{key_label}-----"
end
original_uri_match?(destination_url, settings_url) click to toggle source

If Rails' URI.parse can't match to valid URL, default back to the original matching service. @return [Boolean]

# File lib/cie/ruby-saml/utils.rb, line 211
def self.original_uri_match?(destination_url, settings_url)
  destination_url == settings_url
end
retrieve_plaintext(cipher_text, symmetric_key, algorithm) click to toggle source

Obtains the deciphered text @param cipher_text [String] The ciphered text @param symmetric_key [String] The symetric key used to encrypt the text @param algorithm [String] The encrypted algorithm @return [String] The deciphered text

# File lib/cie/ruby-saml/utils.rb, line 158
def self.retrieve_plaintext(cipher_text, symmetric_key, algorithm)
  case algorithm
    when 'http://www.w3.org/2001/04/xmlenc#tripledes-cbc' then cipher = OpenSSL::Cipher.new('DES-EDE3-CBC').decrypt
    when 'http://www.w3.org/2001/04/xmlenc#aes128-cbc' then cipher = OpenSSL::Cipher.new('AES-128-CBC').decrypt
    when 'http://www.w3.org/2001/04/xmlenc#aes192-cbc' then cipher = OpenSSL::Cipher.new('AES-192-CBC').decrypt
    when 'http://www.w3.org/2001/04/xmlenc#aes256-cbc' then cipher = OpenSSL::Cipher.new('AES-256-CBC').decrypt
    when 'http://www.w3.org/2001/04/xmlenc#rsa-1_5' then rsa = symmetric_key
    when 'http://www.w3.org/2001/04/xmlenc#rsa-oaep-mgf1p' then oaep = symmetric_key
  end

  if cipher
    iv_len = cipher.iv_len
    data = cipher_text[iv_len..-1]
    cipher.padding, cipher.key, cipher.iv = 0, symmetric_key, cipher_text[0..iv_len-1]
    assertion_plaintext = cipher.update(data)
    assertion_plaintext << cipher.final
  elsif rsa
    rsa.private_decrypt(cipher_text)
  elsif oaep
    oaep.private_decrypt(cipher_text, OpenSSL::PKey::RSA::PKCS1_OAEP_PADDING)
  else
    cipher_text
  end
end
retrieve_symmetric_key(encrypt_data, private_key) click to toggle source

Obtains the symmetric key from the EncryptedData element @param encrypt_data [REXML::Element] The EncryptedData element @param private_key [OpenSSL::PKey::RSA] The Service provider private key @return [String] The symmetric key

# File lib/cie/ruby-saml/utils.rb, line 131
def self.retrieve_symmetric_key(encrypt_data, private_key)
  encrypted_key = REXML::XPath.first(
    encrypt_data,
    "//xenc:EncryptedData/ds:KeyInfo/xenc:EncryptedKey or \
     //xenc:EncryptedKey[@Id=substring-after(//xenc:EncryptedData/ds:KeyInfo/ds:RetrievalMethod/@URI, '#')]",
    { "ds" => DSIG, "xenc" => XENC }
  )
  encrypted_symmetric_key_element = REXML::XPath.first(
    encrypted_key,
    "./xenc:CipherData/xenc:CipherValue",
    { "ds" => DSIG, "xenc" => XENC }
  )
  cipher_text = Base64.decode64(encrypted_symmetric_key_element.text)
  encrypt_method = REXML::XPath.first(
    encrypted_key,
    "./xenc:EncryptionMethod",
    {"ds" => DSIG,  "xenc" => XENC }
  )
  algorithm = encrypt_method.attributes['Algorithm']
  retrieve_plaintext(cipher_text, private_key, algorithm)
end
status_error_msg(error_msg, status_code = nil, status_message = nil) click to toggle source

Build the status error message @param status_code [String] StatusCode value @param status_message [Strig] StatusMessage value @return [String] The status error message

# File lib/cie/ruby-saml/utils.rb, line 88
def self.status_error_msg(error_msg, status_code = nil, status_message = nil)
  unless status_code.nil?
    printable_code = status_code.split(':').last
    error_msg << ', was ' + printable_code
  end

  unless status_message.nil?
    error_msg << ' -> ' + status_message
  end

  error_msg
end
uri_match?(destination_url, settings_url) click to toggle source

Given two strings, attempt to match them as URIs using Rails' parse method. If they can be parsed, then the fully-qualified domain name and the host should performa a case-insensitive match, per the RFC for URIs. If Rails can not parse the string in to URL pieces, return a boolean match of the two strings. This maintains the previous functionality. @return [Boolean]

# File lib/cie/ruby-saml/utils.rb, line 193
def self.uri_match?(destination_url, settings_url)
  dest_uri = URI.parse(destination_url)
  acs_uri = URI.parse(settings_url)

  if dest_uri.scheme.nil? || acs_uri.scheme.nil? || dest_uri.host.nil? || acs_uri.host.nil?
    raise URI::InvalidURIError
  else
    dest_uri.scheme.downcase == acs_uri.scheme.downcase &&
      dest_uri.host.downcase == acs_uri.host.downcase &&
      dest_uri.path == acs_uri.path &&
      dest_uri.query == acs_uri.query
  end
rescue URI::InvalidURIError
  original_uri_match?(destination_url, settings_url)
end
uuid() click to toggle source
# File lib/cie/ruby-saml/utils.rb, line 183
def self.uuid
  RUBY_VERSION < '1.9' ? "_#{@@uuid_generator.generate}" : "_#{SecureRandom.uuid}"
end
verify_signature(params) click to toggle source

Validate the Signature parameter sent on the HTTP-Redirect binding @param params [Hash] Parameters to be used in the validation process @option params [OpenSSL::X509::Certificate] cert The Identity provider public certtificate @option params [String] sig_alg The SigAlg parameter @option params [String] signature The Signature parameter (base64 encoded) @option params [String] query_string The full GET Query String to be compared @return [Boolean] True if the Signature is valid, False otherwise

# File lib/cie/ruby-saml/utils.rb, line 78
def self.verify_signature(params)
  cert, sig_alg, signature, query_string = [:cert, :sig_alg, :signature, :query_string].map { |k| params[k]}
  signature_algorithm = Cie::XMLSecurityNew::BaseDocument.new.algorithm(sig_alg)
  return cert.public_key.verify(signature_algorithm.new, Base64.decode64(signature), query_string)
end