1 files changed, 101 insertions, 0 deletions
diff --git a/libraries/spongycastle/prov/src/main/java/org/spongycastle/x509/extension/X509ExtensionUtil.java b/libraries/spongycastle/prov/src/main/java/org/spongycastle/x509/extension/X509ExtensionUtil.java
new file mode 100644
index 000000000..4a6a93d67
--- /dev/null
+++ b/libraries/spongycastle/prov/src/main/java/org/spongycastle/x509/extension/X509ExtensionUtil.java
@@ -0,0 +1,101 @@
+package org.spongycastle.x509.extension;
+
+import java.io.IOException;
+import java.security.cert.CertificateParsingException;
+import java.security.cert.X509Certificate;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.List;
+
+import org.spongycastle.asn1.ASN1ObjectIdentifier;
+import org.spongycastle.asn1.ASN1OctetString;
+import org.spongycastle.asn1.ASN1Primitive;
+import org.spongycastle.asn1.ASN1String;
+import org.spongycastle.asn1.DEROctetString;
+import org.spongycastle.asn1.DERSequence;
+import org.spongycastle.asn1.x500.X500Name;
+import org.spongycastle.asn1.x509.GeneralName;
+import org.spongycastle.asn1.x509.X509Extension;
+import org.spongycastle.util.Integers;
+
+
+public class X509ExtensionUtil
+{
+    public static ASN1Primitive fromExtensionValue(
+        byte[]  encodedValue) 
+        throws IOException
+    {
+        ASN1OctetString octs = (ASN1OctetString)ASN1Primitive.fromByteArray(encodedValue);
+        
+        return ASN1Primitive.fromByteArray(octs.getOctets());
+    }
+
+    public static Collection getIssuerAlternativeNames(X509Certificate cert)
+            throws CertificateParsingException
+    {
+        byte[] extVal = cert.getExtensionValue(X509Extension.issuerAlternativeName.getId());
+
+        return getAlternativeNames(extVal);
+    }
+
+    public static Collection getSubjectAlternativeNames(X509Certificate cert)
+            throws CertificateParsingException
+    {        
+        byte[] extVal = cert.getExtensionValue(X509Extension.subjectAlternativeName.getId());
+
+        return getAlternativeNames(extVal);
+    }
+
+    private static Collection getAlternativeNames(byte[] extVal)
+        throws CertificateParsingException
+    {
+        if (extVal == null)
+        {
+            return Collections.EMPTY_LIST;
+        }
+        try
+        {
+            Collection temp = new ArrayList();
+            Enumeration it = DERSequence.getInstance(fromExtensionValue(extVal)).getObjects();
+            while (it.hasMoreElements())
+            {
+                GeneralName genName = GeneralName.getInstance(it.nextElement());
+                List list = new ArrayList();
+                list.add(Integers.valueOf(genName.getTagNo()));
+                switch (genName.getTagNo())
+                {
+                case GeneralName.ediPartyName:
+                case GeneralName.x400Address:
+                case GeneralName.otherName:
+                    list.add(genName.getName().toASN1Primitive());
+                    break;
+                case GeneralName.directoryName:
+                    list.add(X500Name.getInstance(genName.getName()).toString());
+                    break;
+                case GeneralName.dNSName:
+                case GeneralName.rfc822Name:
+                case GeneralName.uniformResourceIdentifier:
+                    list.add(((ASN1String)genName.getName()).getString());
+                    break;
+                case GeneralName.registeredID:
+                    list.add(ASN1ObjectIdentifier.getInstance(genName.getName()).getId());
+                    break;
+                case GeneralName.iPAddress:
+                    list.add(DEROctetString.getInstance(genName.getName()).getOctets());
+                    break;
+                default:
+                    throw new IOException("Bad tag number: " + genName.getTagNo());
+                }
+
+                temp.add(list);
+            }
+            return Collections.unmodifiableCollection(temp);
+        }
+        catch (Exception e)
+        {
+            throw new CertificateParsingException(e.getMessage());
+        }
+    }
+}