jdk/src/share/classes/sun/security/provider/certpath/X509CertificatePair.java
changeset 2 90ce3da70b43
child 5506 202f599c92aa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/sun/security/provider/certpath/X509CertificatePair.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,328 @@
+/*
+ * Copyright 2000-2002 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+package sun.security.provider.certpath;
+
+import java.io.IOException;
+import java.security.GeneralSecurityException;
+import java.security.PublicKey;
+import java.security.cert.CertificateEncodingException;
+import java.security.cert.CertificateException;
+import java.security.cert.X509Certificate;
+import java.security.interfaces.DSAPublicKey;
+
+import javax.security.auth.x500.X500Principal;
+
+import sun.security.util.DerOutputStream;
+import sun.security.util.DerValue;
+import sun.security.util.Cache;
+import sun.security.x509.X509CertImpl;
+import sun.security.provider.X509Factory;
+
+/**
+ * This class represents an X.509 Certificate Pair object, which is primarily
+ * used to hold a pair of cross certificates issued between Certification
+ * Authorities. The ASN.1 structure is listed below. The forward certificate
+ * of the CertificatePair contains a certificate issued to this CA by another
+ * CA. The reverse certificate of the CertificatePair contains a certificate
+ * issued by this CA to another CA. When both the forward and the reverse
+ * certificates are present in the CertificatePair, the issuer name in one
+ * certificate shall match the subject name in the other and vice versa, and
+ * the subject public key in one certificate shall be capable of verifying the
+ * digital signature on the other certificate and vice versa.  If a subject
+ * public key in one certificate does not contain required key algorithm
+ * parameters, then the signature check involving that key is not done.<p>
+ *
+ * The ASN.1 syntax for this object is:
+ * <pre>
+ * CertificatePair      ::=     SEQUENCE {
+ *      forward [0]     Certificate OPTIONAL,
+ *      reverse [1]     Certificate OPTIONAL
+ *                      -- at least one of the pair shall be present -- }
+ * </pre><p>
+ *
+ * This structure uses EXPLICIT tagging. References: Annex A of
+ * X.509(2000), X.509(1997).
+ *
+ * @author      Sean Mullan
+ * @since       1.4
+ */
+
+public class X509CertificatePair {
+
+    /* ASN.1 explicit tags */
+    private static final byte TAG_FORWARD = 0;
+    private static final byte TAG_REVERSE = 1;
+
+    private X509Certificate forward;
+    private X509Certificate reverse;
+    private byte[] encoded;
+
+    private static final Cache cache = Cache.newSoftMemoryCache(750);
+
+    /**
+     * Creates an empty instance of X509CertificatePair.
+     */
+    public X509CertificatePair() {}
+
+    /**
+     * Creates an instance of X509CertificatePair. At least one of
+     * the pair must be non-null.
+     *
+     * @param forward The forward component of the certificate pair
+     *          which represents a certificate issued to this CA by other CAs.
+     * @param reverse The reverse component of the certificate pair
+     *          which represents a certificate issued by this CA to other CAs.
+     * @throws CertificateException If an exception occurs.
+     */
+    public X509CertificatePair(X509Certificate forward, X509Certificate reverse)
+                throws CertificateException {
+        if (forward == null && reverse == null) {
+            throw new CertificateException("at least one of certificate pair "
+                + "must be non-null");
+        }
+
+        this.forward = forward;
+        this.reverse = reverse;
+
+        checkPair();
+    }
+
+    /**
+     * Create a new X509CertificatePair from its encoding.
+     *
+     * For internal use only, external code should use generateCertificatePair.
+     */
+    private X509CertificatePair(byte[] encoded)throws CertificateException {
+        try {
+            parse(new DerValue(encoded));
+            this.encoded = encoded;
+        } catch (IOException ex) {
+            throw new CertificateException(ex.toString());
+        }
+        checkPair();
+    }
+
+    /**
+     * Clear the cache for debugging.
+     */
+    public static synchronized void clearCache() {
+        cache.clear();
+    }
+
+    /**
+     * Create a X509CertificatePair from its encoding. Uses cache lookup
+     * if possible.
+     */
+    public static synchronized X509CertificatePair generateCertificatePair
+            (byte[] encoded) throws CertificateException {
+        Object key = new Cache.EqualByteArray(encoded);
+        X509CertificatePair pair = (X509CertificatePair)cache.get(key);
+        if (pair != null) {
+            return pair;
+        }
+        pair = new X509CertificatePair(encoded);
+        key = new Cache.EqualByteArray(pair.encoded);
+        cache.put(key, pair);
+        return pair;
+    }
+
+    /**
+     * Sets the forward component of the certificate pair.
+     */
+    public void setForward(X509Certificate cert) throws CertificateException {
+        checkPair();
+        forward = cert;
+    }
+
+    /**
+     * Sets the reverse component of the certificate pair.
+     */
+    public void setReverse(X509Certificate cert) throws CertificateException {
+        checkPair();
+        reverse = cert;
+    }
+
+    /**
+     * Returns the forward component of the certificate pair.
+     *
+     * @return The forward certificate, or null if not set.
+     */
+    public X509Certificate getForward() {
+        return forward;
+    }
+
+    /**
+     * Returns the reverse component of the certificate pair.
+     *
+     * @return The reverse certificate, or null if not set.
+     */
+    public X509Certificate getReverse() {
+        return reverse;
+    }
+
+    /**
+     * Return the DER encoded form of the certificate pair.
+     *
+     * @return The encoded form of the certificate pair.
+     * @throws CerticateEncodingException If an encoding exception occurs.
+     */
+    public byte[] getEncoded() throws CertificateEncodingException {
+        try {
+            if (encoded == null) {
+                DerOutputStream tmp = new DerOutputStream();
+                emit(tmp);
+                encoded = tmp.toByteArray();
+            }
+        } catch (IOException ex) {
+            throw new CertificateEncodingException(ex.toString());
+        }
+        return encoded;
+    }
+
+    /**
+     * Return a printable representation of the certificate pair.
+     *
+     * @return A String describing the contents of the pair.
+     */
+    public String toString() {
+        StringBuffer sb = new StringBuffer();
+        sb.append("X.509 Certificate Pair: [\n");
+        if (forward != null)
+            sb.append("  Forward: " + forward + "\n");
+        if (reverse != null)
+            sb.append("  Reverse: " + reverse + "\n");
+        sb.append("]");
+        return sb.toString();
+    }
+
+    /* Parse the encoded bytes */
+    private void parse(DerValue val)
+        throws IOException, CertificateException
+    {
+        if (val.tag != DerValue.tag_Sequence) {
+            throw new IOException
+                ("Sequence tag missing for X509CertificatePair");
+        }
+
+        while (val.data != null && val.data.available() != 0) {
+            DerValue opt = val.data.getDerValue();
+            short tag = (byte) (opt.tag & 0x01f);
+            switch (tag) {
+                case TAG_FORWARD:
+                    if (opt.isContextSpecific() && opt.isConstructed()) {
+                        if (forward != null) {
+                            throw new IOException("Duplicate forward "
+                                + "certificate in X509CertificatePair");
+                        }
+                        opt = opt.data.getDerValue();
+                        forward = X509Factory.intern
+                                        (new X509CertImpl(opt.toByteArray()));
+                    }
+                    break;
+                case TAG_REVERSE:
+                    if (opt.isContextSpecific() && opt.isConstructed()) {
+                        if (reverse != null) {
+                            throw new IOException("Duplicate reverse "
+                                + "certificate in X509CertificatePair");
+                        }
+                        opt = opt.data.getDerValue();
+                        reverse = X509Factory.intern
+                                        (new X509CertImpl(opt.toByteArray()));
+                    }
+                    break;
+                default:
+                    throw new IOException("Invalid encoding of "
+                        + "X509CertificatePair");
+            }
+        }
+        if (forward == null && reverse == null) {
+            throw new CertificateException("at least one of certificate pair "
+                + "must be non-null");
+        }
+    }
+
+    /* Translate to encoded bytes */
+    private void emit(DerOutputStream out)
+        throws IOException, CertificateEncodingException
+    {
+        DerOutputStream tagged = new DerOutputStream();
+
+        if (forward != null) {
+            DerOutputStream tmp = new DerOutputStream();
+            tmp.putDerValue(new DerValue(forward.getEncoded()));
+            tagged.write(DerValue.createTag(DerValue.TAG_CONTEXT,
+                         true, TAG_FORWARD), tmp);
+        }
+
+        if (reverse != null) {
+            DerOutputStream tmp = new DerOutputStream();
+            tmp.putDerValue(new DerValue(reverse.getEncoded()));
+            tagged.write(DerValue.createTag(DerValue.TAG_CONTEXT,
+                         true, TAG_REVERSE), tmp);
+        }
+
+        out.write(DerValue.tag_Sequence, tagged);
+    }
+
+    /*
+     * Check for a valid certificate pair
+     */
+    private void checkPair() throws CertificateException {
+
+        /* if either of pair is missing, return w/o error */
+        if (forward == null || reverse == null) {
+            return;
+        }
+        /*
+         * If both elements of the pair are present, check that they
+         * are a valid pair.
+         */
+        X500Principal fwSubject = forward.getSubjectX500Principal();
+        X500Principal fwIssuer = forward.getIssuerX500Principal();
+        X500Principal rvSubject = reverse.getSubjectX500Principal();
+        X500Principal rvIssuer = reverse.getIssuerX500Principal();
+        if (!fwIssuer.equals(rvSubject) || !rvIssuer.equals(fwSubject)) {
+            throw new CertificateException("subject and issuer names in "
+                + "forward and reverse certificates do not match");
+        }
+
+        /* check signatures unless key parameters are missing */
+        try {
+            PublicKey pk = reverse.getPublicKey();
+            if (!(pk instanceof DSAPublicKey) ||
+                        ((DSAPublicKey)pk).getParams() != null) {
+                forward.verify(pk);
+            }
+            pk = forward.getPublicKey();
+            if (!(pk instanceof DSAPublicKey) ||
+                        ((DSAPublicKey)pk).getParams() != null) {
+                reverse.verify(pk);
+            }
+        } catch (GeneralSecurityException e) {
+            throw new CertificateException("invalid signature: "
+                + e.getMessage());
+        }
+    }
+}