Class: XMLSecurity::SignedDocument
- Inherits:
-
REXML::Document
- Object
- REXML::Document
- XMLSecurity::SignedDocument
- Defined in:
- lib/xml_security.rb
Instance Method Summary collapse
- #decode(private_key) ⇒ Object
- #validate(idp_cert_fingerprint, logger = nil, private_key = nil) ⇒ Object
- #validate_doc(cert, logger) ⇒ Object
Instance Method Details
#decode(private_key) ⇒ Object
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# File 'lib/xml_security.rb', line 129 def decode private_key # This is the public key which encrypted the first CipherValue certs = REXML::XPath.match(self, '//ds:X509Certificate')#, 'ds' => "http://www.w3.org/2000/09/xmldsig#") array two elements dcert = REXML::XPath.first(self, '//ds:X509Certificate')#, 'ds' => "http://www.w3.org/2000/09/xmldsig#") #Find the certificate for the private key cert = certs.select{|c| OpenSSL::X509::Certificate.new(Base64.decode64(c.text)).check_private_key(private_key)} unless cert.empty? cert = cert[0] else return false end c1, c2 = REXML::XPath.match(self, '//xenc:CipherValue', 'xenc' => 'http://www.w3.org/2001/04/xmlenc#') # Generate the key used for the cipher below via the RSA::OAEP algo rsak = RSA::Key.new private_key.n, private_key.d v1s = Base64.decode64(c1.text) begin cipherkey = RSA::OAEP.decode rsak, v1s rescue RSA::OAEP::DecodeError return false end # The aes-128-cbc cipher has a 128 bit initialization vector (16 bytes) # and this is the first 16 bytes of the raw string. bytes = Base64.decode64(c2.text).bytes.to_a iv = bytes[0...16].pack('c*') others = bytes[16..-1].pack('c*') cipher = OpenSSL::Cipher.new('aes-128-cbc') cipher.decrypt cipher.iv = iv cipher.key = cipherkey out = cipher.update(others) # The encrypted string's length might not be a multiple of the block # length of aes-128-cbc (16), so add in another block and then trim # off the padding. More info about padding is available at # http://www.w3.org/TR/2002/REC-xmlenc-core-20021210/Overview.html in # Section 5.2 out << cipher.update("\x00" * 16) padding = out.bytes.to_a.last self.class.new(out[0..-(padding + 1)]) end |
#validate(idp_cert_fingerprint, logger = nil, private_key = nil) ⇒ Object
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# File 'lib/xml_security.rb', line 71 def validate (idp_cert_fingerprint, logger = nil, private_key = nil) # get cert from response base64_cert = self.elements["//ds:X509Certificate"].text cert_text = Base64.decode64(base64_cert) cert = OpenSSL::X509::Certificate.new(cert_text) # check cert matches registered idp cert fingerprint = Digest::SHA1.hexdigest(cert.to_der) valid_flag = fingerprint == idp_cert_fingerprint.gsub(":", "").downcase return valid_flag if !valid_flag if validate_doc(base64_cert, logger) return true elsif private_key return decode(private_key) else return false end end |
#validate_doc(cert, logger) ⇒ Object
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# File 'lib/xml_security.rb', line 92 def validate_doc(cert, logger) # validate references # remove signature node sig_element = REXML::XPath.first(self, "//ds:Signature", {"ds"=>"http://www.w3.org/2000/09/xmldsig#"}) return false unless sig_element sig_element.remove # #check digests REXML::XPath.each(sig_element, "//ds:Reference", {"ds"=>"http://www.w3.org/2000/09/xmldsig#"}) do | ref | uri = ref.attributes.get_attribute("URI").value hashed_element = REXML::XPath.first(self, "//[@ID='#{uri[1,uri.size]}']") canoner = XML::Util::XmlCanonicalizer.new(false, true) canon_hashed_element = canoner.canonicalize(hashed_element) hash = Base64.encode64(Digest::SHA1.digest(canon_hashed_element)).chomp digest_value = REXML::XPath.first(ref, "//ds:DigestValue", {"ds"=>"http://www.w3.org/2000/09/xmldsig#"}).text valid_flag = hash == digest_value return valid_flag if !valid_flag end # verify signature canoner = XML::Util::XmlCanonicalizer.new(false, true) signed_info_element = REXML::XPath.first(sig_element, "//ds:SignedInfo", {"ds"=>"http://www.w3.org/2000/09/xmldsig#"}) canon_string = canoner.canonicalize(signed_info_element) base64_signature = REXML::XPath.first(sig_element, "//ds:SignatureValue", {"ds"=>"http://www.w3.org/2000/09/xmldsig#"}).text signature = Base64.decode64(base64_signature) # get certificate object valid_flag = cert.public_key.verify(OpenSSL::Digest::SHA1.new, signature, canon_string) return valid_flag end |