v2.0 Support EC/DSA crypto

Author: johnnyshields

lib/ruby_saml/authrequest.rb

@@ -77,14 +77,14 @@ def create_params(settings, params={})
       sp_signing_key = settings.get_sp_signing_key
 
       if binding_redirect && settings.security[:authn_requests_signed] && sp_signing_key
-        params['SigAlg'] = settings.security[:signature_method]
+        params['SigAlg'] = settings.get_sp_signature_method
         url_string = RubySaml::Utils.build_query(
           type: 'SAMLRequest',
           data: base64_request,
           relay_state: relay_state,
           sig_alg: params['SigAlg']
         )
-        sign_algorithm = RubySaml::XML::BaseDocument.new.algorithm(settings.security[:signature_method])
+        sign_algorithm = RubySaml::XML::Crypto.hash_algorithm(settings.get_sp_signature_method)
         signature = sp_signing_key.sign(sign_algorithm.new, url_string)
         params['Signature'] = encode(signature)
       end
@@ -185,7 +185,7 @@ def create_xml_document(settings)
     def sign_document(document, settings)
       cert, private_key = settings.get_sp_signing_pair
       if settings.idp_sso_service_binding == Utils::BINDINGS[:post] && settings.security[:authn_requests_signed] && private_key && cert
-        document.sign_document(private_key, cert, settings.security[:signature_method], settings.security[:digest_method])
+        document.sign_document(private_key, cert, settings.get_sp_signature_method, settings.get_sp_digest_method)
       end
 
       document

lib/ruby_saml/idp_metadata_parser.rb

@@ -398,7 +398,7 @@ def fingerprint(certificate, fingerprint_algorithm = RubySaml::XML::Document::SH
 
           cert = OpenSSL::X509::Certificate.new(Base64.decode64(certificate))
 
-          fingerprint_alg = RubySaml::XML::BaseDocument.new.algorithm(fingerprint_algorithm).new
+          fingerprint_alg = RubySaml::XML::Crypto.hash_algorithm(fingerprint_algorithm).new
           fingerprint_alg.hexdigest(cert.to_der).upcase.scan(/../).join(":")
         end
       end

lib/ruby_saml/logoutrequest.rb

@@ -75,14 +75,14 @@ def create_params(settings, params={})
       sp_signing_key = settings.get_sp_signing_key
 
       if binding_redirect && settings.security[:logout_requests_signed] && sp_signing_key
-        params['SigAlg'] = settings.security[:signature_method]
+        params['SigAlg'] = settings.get_sp_signature_method
         url_string = RubySaml::Utils.build_query(
           type: 'SAMLRequest',
           data: base64_request,
           relay_state: relay_state,
           sig_alg: params['SigAlg']
         )
-        sign_algorithm = RubySaml::XML::BaseDocument.new.algorithm(settings.security[:signature_method])
+        sign_algorithm = RubySaml::XML::Crypto.hash_algorithm(settings.get_sp_signature_method)
         signature = settings.get_sp_signing_key.sign(sign_algorithm.new, url_string)
         params['Signature'] = encode(signature)
       end
@@ -144,7 +144,7 @@ def sign_document(document, settings)
       # embed signature
       cert, private_key = settings.get_sp_signing_pair
       if settings.idp_slo_service_binding == Utils::BINDINGS[:post] && settings.security[:logout_requests_signed] && private_key && cert
-        document.sign_document(private_key, cert, settings.security[:signature_method], settings.security[:digest_method])
+        document.sign_document(private_key, cert, settings.get_sp_signature_method, settings.get_sp_digest_method)
       end
 
       document

lib/ruby_saml/metadata.rb

@@ -142,7 +142,7 @@ def embed_signature(meta_doc, settings)
       cert, private_key = settings.get_sp_signing_pair
       return unless private_key && cert
 
-      meta_doc.sign_document(private_key, cert, settings.security[:signature_method], settings.security[:digest_method])
+      meta_doc.sign_document(private_key, cert, settings.get_sp_signature_method, settings.get_sp_digest_method)
     end
 
     def output_xml(meta_doc, pretty_print)

lib/ruby_saml/settings.rb

@@ -126,7 +126,7 @@ def get_fingerprint
       idp_cert_fingerprint || begin
         idp_cert = get_idp_cert
         if idp_cert
-          fingerprint_alg = RubySaml::XML::BaseDocument.new.algorithm(idp_cert_fingerprint_algorithm).new
+          fingerprint_alg = RubySaml::XML::Crypto.hash_algorithm(idp_cert_fingerprint_algorithm).new
           fingerprint_alg.hexdigest(idp_cert.to_der).upcase.scan(/../).join(":")
         end
       end
@@ -159,7 +159,7 @@ def get_idp_cert_multi
       certs
     end
 
-    # @return [Hash<Symbol, Array<Array<OpenSSL::X509::Certificate, OpenSSL::PKey::RSA>>>]
+    # @return [Hash<Symbol, Array<Array<OpenSSL::X509::Certificate, OpenSSL::PKey::PKey>>>]
     #   Build the SP certificates and private keys from the settings. If
     #   check_sp_cert_expiration is true, only returns certificates and private keys
     #   that are not expired.
@@ -179,7 +179,7 @@ def get_sp_certs
       active_certs.freeze
     end
 
-    # @return [Array<OpenSSL::X509::Certificate, OpenSSL::PKey::RSA>]
+    # @return [Array<OpenSSL::X509::Certificate, OpenSSL::PKey::PKey>]
     #   The SP signing certificate and private key.
     def get_sp_signing_pair
       get_sp_certs[:signing].first
@@ -267,6 +267,44 @@ def get_binding(value)
       end
     end
 
+    # @return [String] The XML Signature Algorithm attribute.
+    #
+    # This method is intentionally hacky for backwards compatibility of the
+    # settings.security[:signature_method] parameter. Previously, this parameter
+    # could have a value such as "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256",
+    # which assumes the public key type RSA. To add support for DSA and ECDSA, we will now
+    # ignore the "rsa-" prefix and only use the "sha256" hash algorithm component.
+    def get_sp_signature_method
+      sig_alg = security[:signature_method] || 'sha1' # TODO: change to sha256 by default
+      hash_alg = sig_alg.to_s.match(/(?:\A|[#_-])(sha\d+)\z/i)[1]
+      key_alg = case get_sp_signing_key
+                when OpenSSL::PKey::RSA then 'RSA'
+                when OpenSSL::PKey::DSA then 'DSA'
+                when OpenSSL::PKey::EC  then 'ECDSA'
+                else # rubocop:disable Lint/DuplicateBranch
+                  # raise ArgumentError.new("Unsupported signing key type: #{get_sp_signing_key.class}")
+                  'RSA'
+                end
+
+      begin
+        RubySaml::XML::Crypto.const_get("#{key_alg}_#{hash_alg}".upcase)
+      rescue NameError
+        raise ArgumentError.new("Unsupported signature method: #{sig_alg}")
+      end
+    end
+
+    # @return [String] The XML Signature Digest attribute.
+    def get_sp_digest_method
+      digest_alg = security[:digest_method] || 'sha1' # TODO: change to sha256 by default
+      alg = digest_alg.to_s.match(/(?:\A|#)(sha\d+)\z/i)[1]
+
+      begin
+        RubySaml::XML::Crypto.const_get(alg.upcase)
+      rescue NameError
+        raise ArgumentError.new("Unsupported signature method: #{digest_alg}")
+      end
+    end
+
     # @deprecated Will be removed in v2.1.0
     def certificate_new
       certificate_new_deprecation

lib/ruby_saml/slo_logoutresponse.rb

@@ -84,14 +84,14 @@ def create_params(settings, request_id = nil, logout_message = nil, params = {},
       sp_signing_key = settings.get_sp_signing_key
 
       if binding_redirect && settings.security[:logout_responses_signed] && sp_signing_key
-        params['SigAlg'] = settings.security[:signature_method]
+        params['SigAlg'] = settings.get_sp_signature_method
         url_string = RubySaml::Utils.build_query(
           type: 'SAMLResponse',
           data: base64_response,
           relay_state: relay_state,
           sig_alg: params['SigAlg']
         )
-        sign_algorithm = RubySaml::XML::BaseDocument.new.algorithm(settings.security[:signature_method])
+        sign_algorithm = RubySaml::XML::Crypto.hash_algorithm(settings.get_sp_signature_method)
         signature = sp_signing_key.sign(sign_algorithm.new, url_string)
         params['Signature'] = encode(signature)
       end
@@ -155,7 +155,7 @@ def sign_document(document, settings)
       # embed signature
       cert, private_key = settings.get_sp_signing_pair
       if settings.idp_slo_service_binding == Utils::BINDINGS[:post] && private_key && cert
-        document.sign_document(private_key, cert, settings.security[:signature_method], settings.security[:digest_method])
+        document.sign_document(private_key, cert, settings.get_sp_signature_method, settings.get_sp_digest_method)
       end
 
       document

lib/ruby_saml/utils.rb

@@ -123,15 +123,14 @@ 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_algo = key.match(/((?:RSA|DSA|EC|ECDSA) )PRIVATE KEY/)&.[](1)
+      key = key.gsub(/-{5}\s?(BEGIN|END)( (?:RSA|DSA|EC|ECDSA))? PRIVATE KEY\s?-{5}/, "")
       key = key.gsub(/\n/, "")
       key = key.gsub(/\r/, "")
       key = key.gsub(/\s/, "")
       key = key.scan(/.{1,64}/)
       key = key.join("\n")
-      key_label = rsa_key ? "RSA PRIVATE KEY" : "PRIVATE KEY"
+      key_label = "#{key_algo}PRIVATE KEY"
       "-----BEGIN #{key_label}-----\n#{key}\n-----END #{key_label}-----"
     end
 
@@ -149,12 +148,25 @@ def self.build_cert_object(cert)
     # Given a private key string, return an OpenSSL::PKey::RSA object.
     #
     # @param cert [String] The original private key
-    # @return [OpenSSL::PKey::RSA] The private key object
+    # @return [OpenSSL::PKey::PKey] The private key object
     #
     def self.build_private_key_object(private_key)
       return nil if private_key.nil? || private_key.empty?
 
-      OpenSSL::PKey::RSA.new(format_private_key(private_key))
+      private_key = format_private_key(private_key)
+      error = nil
+
+      [OpenSSL::PKey::RSA,
+       OpenSSL::PKey::DSA,
+       OpenSSL::PKey::EC].each do |key_class|
+        begin
+          return key_class.new(private_key)
+        rescue OpenSSL::PKey::PKeyError => e
+          error ||= e
+        end
+      end
+
+      raise error
     end
 
     # Build the Query String signature that will be used in the HTTP-Redirect binding
@@ -236,7 +248,7 @@ def self.escape_request_param(param, lowercase_url_encoding)
     #
     def self.verify_signature(params)
       cert, sig_alg, signature, query_string = %i[cert sig_alg signature query_string].map { |k| params[k]}
-      signature_algorithm = RubySaml::XML::BaseDocument.new.algorithm(sig_alg)
+      signature_algorithm = RubySaml::XML::Crypto.hash_algorithm(sig_alg)
       cert.public_key.verify(signature_algorithm.new, Base64.decode64(signature), query_string)
     end
 
@@ -266,7 +278,7 @@ def self.status_error_msg(error_msg, raw_status_code = nil, status_message = nil
     # Obtains the decrypted string from an Encrypted node element in XML,
     # given multiple private keys to try.
     # @param encrypted_node [REXML::Element] The Encrypted element
-    # @param private_keys [Array<OpenSSL::PKey::RSA>] The Service provider private key
+    # @param private_keys [Array<OpenSSL::PKey::PKey>] The Service provider private key
     # @return [String] The decrypted data
     def self.decrypt_multi(encrypted_node, private_keys)
       raise ArgumentError.new('private_keys must be specified') if !private_keys || private_keys.empty?
@@ -285,7 +297,7 @@ def self.decrypt_multi(encrypted_node, private_keys)
 
     # 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
+    # @param private_key [OpenSSL::PKey::PKey] The Service provider private key
     # @return [String] The decrypted data
     def self.decrypt_data(encrypted_node, private_key)
       encrypt_data = REXML::XPath.first(
@@ -311,7 +323,7 @@ def self.decrypt_data(encrypted_node, private_key)
 
     # 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
+    # @param private_key [OpenSSL::PKey::PKey] The Service provider private key
     # @return [String] The symmetric key
     def self.retrieve_symmetric_key(encrypt_data, private_key)
       encrypted_key = REXML::XPath.first(

lib/ruby_saml/xml.rb

@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 
+require 'ruby_saml/xml/crypto'
 require 'ruby_saml/xml/base_document'
 require 'ruby_saml/xml/document'
 require 'ruby_saml/xml/signed_document'

lib/ruby_saml/xml/base_document.rb

@@ -1,55 +1,35 @@
 # frozen_string_literal: true
 
 require 'rexml/document'
+require 'rexml/security'
 require 'rexml/xpath'
 require 'nokogiri'
 require 'openssl'
 require 'digest/sha1'
 require 'digest/sha2'
+require 'ruby_saml/xml/crypto'
 
 module RubySaml
   module XML
     class BaseDocument < REXML::Document
+      # TODO: This affects the global state
       REXML::Security.entity_expansion_limit = 0
 
-      C14N = 'http://www.w3.org/2001/10/xml-exc-c14n#'
-      DSIG = 'http://www.w3.org/2000/09/xmldsig#'
+      # @deprecated Constants moved to Crypto module
+      C14N = RubySaml::XML::Crypto::C14N
+      DSIG = RubySaml::XML::Crypto::DSIG
+
       NOKOGIRI_OPTIONS = Nokogiri::XML::ParseOptions::STRICT |
                          Nokogiri::XML::ParseOptions::NONET
 
-      def canon_algorithm(element)
-        algorithm = element
-        if algorithm.is_a?(REXML::Element)
-          algorithm = element.attribute('Algorithm').value
-        end
-
-        case algorithm
-        when 'http://www.w3.org/TR/2001/REC-xml-c14n-20010315',
-             'http://www.w3.org/TR/2001/REC-xml-c14n-20010315#WithComments'
-          Nokogiri::XML::XML_C14N_1_0
-        when 'http://www.w3.org/2006/12/xml-c14n11',
-             'http://www.w3.org/2006/12/xml-c14n11#WithComments'
-          Nokogiri::XML::XML_C14N_1_1
-        else
-          Nokogiri::XML::XML_C14N_EXCLUSIVE_1_0
-        end
+      # @deprecated Remove in v2.1.0
+      def canon_algorithm(algorithm)
+        RubySaml::XML::Crypto.canon_algorithm(algorithm)
       end
 
-      def algorithm(element)
-        algorithm = element
-        if algorithm.is_a?(REXML::Element)
-          algorithm = element.attribute('Algorithm').value
-        end
-
-        algorithm = algorithm && algorithm =~ /(rsa-)?sha(.*?)$/i && ::Regexp.last_match(2).to_i
-
-        case algorithm
-        when 1 then OpenSSL::Digest::SHA1
-        when 384 then OpenSSL::Digest::SHA384
-        when 512 then OpenSSL::Digest::SHA512
-        else
-          OpenSSL::Digest::SHA256
-        end
+      # @deprecated Remove in v2.1.0
+      def algorithm(algorithm)
+        RubySaml::XML::Crypto.hash_algorithm(algorithm)
       end
     end
   end