package net.deterlab.abac; import java.io.*; import java.math.*; import java.text.*; import java.util.*; import java.security.*; import java.security.cert.*; import javax.xml.parsers.*; import javax.xml.transform.*; import javax.xml.transform.dom.*; import javax.xml.transform.stream.*; import javax.xml.crypto.*; import javax.xml.crypto.dsig.*; import javax.xml.crypto.dsig.dom.*; import javax.xml.crypto.dsig.keyinfo.*; import javax.xml.crypto.dsig.spec.*; import org.xml.sax.*; import org.w3c.dom.*; /** * An ABAC credential formatted as an abac-type GENI credential. * @author ISI ABAC team * @version 1.4 */ public class GENICredential extends Credential implements Comparable { /** The signed XML representing this credential */ protected Document doc; /** The GENI credential suffix */ private static final String fileSuffix = ".xml"; /** * X509KeySelector implementation from * http://www.outsourcingi.com/art-271-Programming-With-the-Java-XML-Digital-Signature-API.html * . * * Straight ahead extraction of a key from an X509 cert, but it is their * code and hard to improve on. */ static protected class X509KeySelector extends KeySelector { public KeySelectorResult select(KeyInfo keyInfo, KeySelector.Purpose purpose, AlgorithmMethod method, XMLCryptoContext context) throws KeySelectorException { Iterator ki = keyInfo.getContent().iterator(); while (ki.hasNext()) { XMLStructure info = (XMLStructure) ki.next(); if (!(info instanceof X509Data)) continue; X509Data x509Data = (X509Data) info; Iterator xi = x509Data.getContent().iterator(); while (xi.hasNext()) { Object o = xi.next(); if (!(o instanceof X509Certificate)) continue; final PublicKey key = ((X509Certificate)o).getPublicKey(); // Make sure the algorithm is compatible // with the method. if (algEquals(method.getAlgorithm(), key.getAlgorithm())) { return new KeySelectorResult() { public Key getKey() { return key; } }; } } } throw new KeySelectorException("No key found!"); } boolean algEquals(String algURI, String algName) { if ((algName.equalsIgnoreCase("DSA") && algURI.equalsIgnoreCase(SignatureMethod.DSA_SHA1)) || (algName.equalsIgnoreCase("RSA") && algURI.equalsIgnoreCase(SignatureMethod.RSA_SHA1))) { return true; } else { return false; } } } /** * Create an empty Credential. */ public GENICredential() { super(); doc = null; setSuffix(fileSuffix); } /** * Create a credential from a head and tail role. This credential has no * underlying certificate, and cannot be exported or used in real proofs. * make_cert can create a certificate for a credential initialized this * way. * @param head the Role at the head of the credential * @param tail the Role at the tail of the credential */ public GENICredential(Role head, Role tail) { super(head, tail); doc = null; setSuffix(fileSuffix); } /** * Do the credential extraction from an input stream. This parses the * certificate from the input stream and saves it. The contents must be * validated and parsed later. * @param stream the InputStream to read the certificate from. * @return the parsed XML document * @throws IOException if the stream is unparsable */ static protected Document read_certificate(InputStream stream) throws IOException { DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); DocumentBuilder db = null; Document ldoc = null; if ( dbf == null ) throw new IOException("Cannot get DocumentBuilderFactory!?"); try { /* Note this setting is required to find the properly * namespace-scoped signature block in the credential. */ dbf.setNamespaceAware(true); if ( (db = dbf.newDocumentBuilder()) == null ) throw new IOException("Cannot get DocumentBuilder!?"); ldoc = db.parse(stream); ldoc.normalizeDocument(); return ldoc; } catch (IllegalArgumentException ie) { throw new IOException("null stream", ie); } catch (SAXException se) { throw new IOException(se.getMessage(), se); } catch (Exception e) { throw new IOException(e.getMessage(), e); } } /** * Walk the document and set all instances of an xml:id attribute to be ID * attributes in terms of the java libraries. This is needed for the * signature code to find signed subsections. The "xml:id" is treated as * both a namespace free ID with a colon and as an "id" identifier in the * "xml" namespace so we don't miss it. * @param n the root of the document to mark */ static protected void setIDAttrs(Node n) { if ( n.getNodeType() == Node.ELEMENT_NODE) { Element e = (Element) n; String id = e.getAttribute("xml:id"); if ( id != null && id.length() > 0 ) e.setIdAttribute("xml:id", true); id = e.getAttributeNS("xml", "id"); if ( id != null && id.length() > 0 ) e.setIdAttributeNS("xml", "id", true); } for (Node nn = n.getFirstChild(); nn != null; nn = nn.getNextSibling()) setIDAttrs(nn); } /** * Return the child of Node n that has the given name, if there is one. * @param n a Node to search * @param name the name to search for * @return a Node with the name, may be null */ static protected Node getChildByName(Node n, String name) { if (name == null ) return null; for (Node nn = n.getFirstChild(); nn != null; nn = nn.getNextSibling()) if ( nn.getNodeType() == Node.ELEMENT_NODE && name.equals(nn.getNodeName())) return nn; return null; } /** * Find the X509Certificate in the Signature element and convert it to an * ABAC identity. This assumes a KeyInfo in that section holding an * X509Data section containing the certificate in an X509Certificate * section. Any of that not being found will cause a failure. If the * Identity cannot be created a Gignature exception is thrown. * @param n a Node pointing to a Signature section * @return an Identity constructed frm the X509 Certificate * @throws MissingIssuerException if the Identity cannot be created from the * certificate. */ static protected Identity getIdentity(Node n) throws MissingIssuerException { Identity rv = null; Node nn = getChildByName(n, "KeyInfo"); String certStr = null; if ( nn == null ) return null; if ( ( nn = getChildByName(nn, "X509Data")) == null ) return null; if ( ( nn = getChildByName(nn, "X509Certificate")) == null ) return null; if ( ( certStr = nn.getTextContent()) == null ) return null; try { certStr = "-----BEGIN CERTIFICATE-----\n" + certStr + "\n-----END CERTIFICATE-----"; return new Identity(new StringReader(certStr)); } catch (Exception e) { throw new MissingIssuerException(e.getMessage(), e); } } static protected Date getTime(Document d, String field) throws ABACException { Node root = null; Node n = null; SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssz"); Date date = null; String dstr = null; if ( (root = getChildByName(d, "signed-credential")) == null) throw new CertInvalidException("No signed-credential element"); if ( (n = getChildByName(root, "credential")) == null ) throw new CertInvalidException("No credential element"); if ( (n = getChildByName(n, field)) == null ) throw new CertInvalidException("No " + field + " element"); if ( ( dstr = n.getTextContent()) == null ) throw new CertInvalidException("No expires content"); dstr = dstr.replace("Z", "GMT"); if ((date = df.parse(dstr, new ParsePosition(0))) == null) throw new CertInvalidException("Cannot parse date: "+ n.getTextContent()); return date; } /** * Initialize a credential from parsed certificate. Validiate it against * the given identities and parse out the roles. Note that catching * java.security.GeneralSecurityException catches most of the exceptions * this throws. * @param ids a Collection of Identities to use in validating the cert * @throws CertInvalidException if the stream is unparsable * @throws MissingIssuerException if none of the Identities can validate the * certificate * @throws BadSignatureException if the signature check fails */ protected void init(Collection ids) throws ABACException { XMLSignatureFactory fac = XMLSignatureFactory.getInstance("DOM"); NodeList nl = doc.getElementsByTagNameNS(XMLSignature.XMLNS, "Signature"); DOMValidateContext valContext = null; XMLSignature signature = null; try { if (nl.getLength() == 0) throw new CertInvalidException("Cannot find Signature element"); setIDAttrs(doc); valContext = new DOMValidateContext(new X509KeySelector(), nl.item(0)); if ( valContext == null ) throw new ABACException("No validation context!?"); signature = fac.unmarshalXMLSignature(valContext); if (signature == null) throw new BadSignatureException("Cannot unmarshal signature"); if (!signature.validate(valContext)) throw new BadSignatureException("bad signature"); m_expiration = getTime(doc, "expires"); if ( m_expiration.before(new Date())) throw new CertInvalidException("Certificate Expired " + m_expiration); load_roles(); id = getIdentity(nl.item(0)); if ( !ids.contains(id) ) ids.add(id); if (!id.getKeyID().equals(m_head.principal())) throw new MissingIssuerException("Issuer ID and left hand " + "side principal disagree"); } catch (ABACException ae) { throw ae; } catch (Exception e) { throw new BadSignatureException(e.getMessage(), e); } } /** * Parse a credential from an InputStream and initialize the role from it. * Combine read_credential(stream) and init(ids). Note that catching * java.security.GeneralSecurityException catches most of the exceptions * this throws. * @param stream the InputStream to read the certificate from. * @param ids a Collection of Identities to use in validating the cert * @throws CertInvalidException if the stream is unparsable * @throws MissingIssuerException if none of the Identities can validate the * certificate * @throws BadSignatureException if the signature check fails */ protected void init(InputStream stream, Collection ids) throws ABACException { try { doc = read_certificate(stream); } catch (IOException e) { throw new CertInvalidException("Cannot parse cert", e); } if (doc == null) throw new CertInvalidException("Unknown Format"); init(ids); } /** * Create a credential from an attribute cert in a file. Throws an * exception if the cert file can't be opened or if there's a format * problem with the cert. Note that catching * java.security.GeneralSecurityException catches most of the exceptions * this throws. * @param filename a String containing the filename to read * @param ids a Collection of Identities to use in validating the cert * @throws CertInvalidException if the stream is unparsable * @throws MissingIssuerException if none of the Identities can validate the * certificate * @throws BadSignatureException if the signature check fails */ GENICredential(String filename, Collection ids) throws ABACException { super(); setSuffix(fileSuffix); try { init(new FileInputStream(filename), ids); } catch (FileNotFoundException e) { throw new CertInvalidException("Bad filename", e); } } /** * Create a credential from an attribute cert in a file. Throws an * exception if the cert file can't be opened or if there's a format * problem with the cert. Note that catching * java.security.GeneralSecurityException catches most of the exceptions * this throws. * @param file the File to read * @param ids a Collection of Identities to use in validating the cert * @throws CertInvalidException if the stream is unparsable * @throws MissingIssuerException if none of the Identities can validate the * certificate * @throws BadSignatureException if the signature check fails */ GENICredential(File file, Collection ids) throws ABACException { super(); setSuffix(fileSuffix); try { init(new FileInputStream(file), ids); } catch (FileNotFoundException e) { throw new CertInvalidException("Bad filename", e); } } /** * Create a credential from an InputStream. Throws an exception if the * stream can't be parsed or if there's a format problem with the cert. * Note that catching java.security.GeneralSecurityException catches most * of the exceptions this throws. * @param s the InputStream to read * @param ids a Collection of Identities to use in validating the cert * @throws CertInvalidException if the stream is unparsable * @throws MissingIssuerException if none of the Identities can validate the * certificate * @throws BadSignatureException if the signature check fails */ GENICredential(InputStream s, Collection ids) throws ABACException { super(); setSuffix(fileSuffix); init(s, ids); } /** * Encode the abac credential's XML and set the validity. This is straight * line code that directly builds the credential. * @param validity a long holding the number of seconds that the credential * is valid for. * @return a Node, the place to attach signatures * @throws ABACException if any of the XML construction fails */ protected Node make_rt0_content(long validity) throws ABACException { DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); DocumentBuilder db = null; SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'"); StringBuffer expBuf = new StringBuffer(); /* This is a weirdness to cope with the GENI format. They have a naked * xml:id specifier without any namespace declarations in the * credential. Notice that this is the opposite of the setting used in * init to read a credential. */ dbf.setNamespaceAware(false); if ( dbf == null ) throw new ABACException("Cannot get DocumentBuilderFactory!?"); try { db = dbf.newDocumentBuilder(); } catch (ParserConfigurationException pe) { throw new ABACException("Cannot get DocumentBuilder!?" + pe.getMessage(), pe); } doc = db.newDocument(); if ( doc == null ) throw new ABACException("No Document"); Element root = doc.createElement("signed-credential"); Element cred = doc.createElement("credential"); Element sig = doc.createElement("signatures"); Element e = doc.createElement("type"); Node text = doc.createTextNode("abac"); doc.appendChild(root); cred.setAttribute("xml:id", "ref0"); /* So that the signing code can find the section to sign */ cred.setIdAttribute("xml:id", true); root.appendChild(cred); e.appendChild(text); cred.appendChild(e); m_expiration = new Date(System.currentTimeMillis() + (1000L * validity )); df.setTimeZone(new SimpleTimeZone(0, "Z")); df.format(m_expiration, expBuf, new FieldPosition(0)); e = doc.createElement("expires"); text = doc.createTextNode(expBuf.toString()); e.appendChild(text); cred.appendChild(e); e = doc.createElement("version"); text = doc.createTextNode("1.0"); e.appendChild(text); cred.appendChild(e); e = doc.createElement("rt0"); text = doc.createTextNode(m_head + "<-" + m_tail); e.appendChild(text); cred.appendChild(e); root.appendChild(sig); return sig; } /** * Create a certificate from this credential issued by the given identity * valid for the given time (in seconds). This is the signed XML ABAC * credential. * @param i the Identity that will issue the certificate * @param validity a long holding the number of seconds that the credential * is valid for. * @throws ABACException if xml creation fails * @throws MissingIssuerException if the issuer is bad * @throws BadSignatureException if the signature creation fails */ public void make_cert(Identity i, long validity) throws ABACException { X509Certificate cert = i.getCertificate(); KeyPair kp = i.getKeyPair(); PublicKey pubKey = null; PrivateKey privKey = null; if ( cert == null ) throw new MissingIssuerException("No credential in identity?"); if ( kp == null ) throw new MissingIssuerException("No keypair in identity?"); pubKey = kp.getPublic(); if ((privKey = kp.getPrivate()) == null ) throw new MissingIssuerException("No private ket in identity"); XMLSignatureFactory fac = XMLSignatureFactory.getInstance("DOM"); Reference ref = null; SignedInfo si = null; KeyInfoFactory kif = fac.getKeyInfoFactory(); /* The doesn't say much, but shuts the compiler up about * unchecked references. The lists are polymorphyc and the signature * libs expect that, so is the best we can do. */ List x509Content = new ArrayList(); List keyInfo = new ArrayList(); x509Content.add(cert.getSubjectX500Principal().getName()); x509Content.add(cert); X509Data xd = kif.newX509Data(x509Content); KeyValue kv = null; try { kv = kif.newKeyValue(pubKey); } catch (KeyException ke) { throw new ABACException("Unsupported key format " + ke.getMessage(), ke); } Collections.addAll(keyInfo, kv, xd); KeyInfo ki = kif.newKeyInfo(keyInfo); Node sig = make_rt0_content(validity); try { ref = fac.newReference("#ref0", fac.newDigestMethod(DigestMethod.SHA1, null), Collections.singletonList( fac.newTransform(Transform.ENVELOPED, (TransformParameterSpec) null)), null, null); si = fac.newSignedInfo( fac.newCanonicalizationMethod( CanonicalizationMethod.INCLUSIVE, (C14NMethodParameterSpec) null), fac.newSignatureMethod(SignatureMethod.RSA_SHA1, null), Collections.singletonList(ref)); DOMSignContext dsc = new DOMSignContext(privKey, sig); XMLSignature signature = fac.newXMLSignature(si, ki); signature.sign(dsc); } catch (Exception me) { throw new BadSignatureException(me.getMessage(), me); } } /** * Create a certificate from this credential issued by the given identity * valid for the default validity period. This is the signed XML ABAC * credential. * @param i the Identity that will issue the certificate * @throws ABACException if xml creation fails * @throws MissingIssuerException if the issuer is bad * @throws BadSignatureException if the signature creation fails */ public void make_cert(Identity i) throws ABACException { make_cert(i, defaultValidity); } /** * Load the roles off the attribute cert. * @throws CertInvalidException if the certificate is badly formatted */ private void load_roles() throws CertInvalidException { if ( doc == null ) throw new CertInvalidException("No credential"); NodeList nodes = doc.getElementsByTagName("type"); Node node = null; String roles = null; if (nodes == null || nodes.getLength() != 1) throw new CertInvalidException("More than one type element?"); node = nodes.item(0); if ( node == null ) throw new CertInvalidException("bad rt0 element?"); if ( !"abac".equals(node.getTextContent()) ) throw new CertInvalidException("Not an abac type credential"); nodes = doc.getElementsByTagName("rt0"); if (nodes == null || nodes.getLength() != 1) throw new CertInvalidException("More than one rt0 element?"); node = nodes.item(0); if ( node == null ) throw new CertInvalidException("bad rt0 element?"); if ( (roles = node.getTextContent()) == null ) throw new CertInvalidException("bad rt0 element (no text)?"); String[] parts = roles.split("\\s*<--?\\s*"); if (parts.length != 2) throw new CertInvalidException("Invalid attribute: " + roles); m_head = new Role(parts[0]); m_tail = new Role(parts[1]); } /** * Output the signed GENI ABAC certificate associated with this * Credential to the OutputStream. * @param s the OutputStream on which to write * @throws IOException if there is an error writing. */ public void write(OutputStream s) throws IOException { if ( doc == null ) return; try { TransformerFactory tf = TransformerFactory.newInstance(); Transformer t = tf.newTransformer(); DOMSource source = new DOMSource(doc); StreamResult result = new StreamResult(s); t.transform(source, result); s.flush(); } catch (Exception e) { throw new IOException(e.getMessage(), e); } } /** * Output the signed GENI ABAC certificate associated with this * Credential to the OutputStream. * @param fn a String, the file name on which to write * @throws IOException if there is an error writing. * @throws FileNotFoundExeption if the file path is bogus */ public void write(String fn) throws IOException, FileNotFoundException { write(new FileOutputStream(fn)); } /** * Return true if this Credential has a certificate associated. A jabac * extension. * @return true if this Credential has a certificate associated. */ public boolean hasCertificate() { return doc != null; } /** * Return a CredentialCredentialFactorySpecialization for GENICredentials. * Used by the CredentialFactory to parse and generate these kind of * credentials. It basically wraps constuctor calls. * @return a CredentialFactorySpecialization for this kind of credential. */ static public CredentialFactorySpecialization getCredentialFactorySpecialization() { return new CredentialFactorySpecialization() { public Credential[] parseCredential(InputStream is, Collection ids) throws ABACException { return new Credential[] { new GENICredential(is, ids) }; } public Credential generateCredential(Role head, Role tail) { return new GENICredential(head, tail); } }; } }