1 files changed, 91 insertions, 0 deletions
diff --git a/pkix/src/main/java/org/spongycastle/cert/bc/BcX509ExtensionUtils.java b/pkix/src/main/java/org/spongycastle/cert/bc/BcX509ExtensionUtils.java
new file mode 100644
index 00000000..6d4dc217
--- /dev/null
+++ b/pkix/src/main/java/org/spongycastle/cert/bc/BcX509ExtensionUtils.java
@@ -0,0 +1,91 @@
+package org.spongycastle.cert.bc;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+
+import org.spongycastle.asn1.oiw.OIWObjectIdentifiers;
+import org.spongycastle.asn1.x509.AlgorithmIdentifier;
+import org.spongycastle.asn1.x509.AuthorityKeyIdentifier;
+import org.spongycastle.asn1.x509.SubjectKeyIdentifier;
+import org.spongycastle.cert.X509ExtensionUtils;
+import org.spongycastle.crypto.Digest;
+import org.spongycastle.crypto.digests.SHA1Digest;
+import org.spongycastle.crypto.params.AsymmetricKeyParameter;
+import org.spongycastle.crypto.util.SubjectPublicKeyInfoFactory;
+import org.spongycastle.operator.DigestCalculator;
+
+public class BcX509ExtensionUtils
+    extends X509ExtensionUtils
+{
+    /**
+     * Create a utility class pre-configured with a SHA-1 digest calculator based on the
+     * BC implementation.
+     */
+    public BcX509ExtensionUtils()
+    {
+        super(new SHA1DigestCalculator());
+    }
+
+    public BcX509ExtensionUtils(DigestCalculator calculator)
+    {
+        super(calculator);
+    }
+
+    public AuthorityKeyIdentifier createAuthorityKeyIdentifier(
+        AsymmetricKeyParameter publicKey)
+        throws IOException
+    {
+        return super.createAuthorityKeyIdentifier(SubjectPublicKeyInfoFactory.createSubjectPublicKeyInfo(publicKey));
+    }
+
+    /**
+     * Return a RFC 3280 type 1 key identifier. As in:
+     * <pre>
+     * (1) The keyIdentifier is composed of the 160-bit SHA-1 hash of the
+     * value of the BIT STRING subjectPublicKey (excluding the tag,
+     * length, and number of unused bits).
+     * </pre>
+     * @param publicKey the key object containing the key identifier is to be based on.
+     * @return the key identifier.
+     */
+    public SubjectKeyIdentifier createSubjectKeyIdentifier(
+        AsymmetricKeyParameter publicKey)
+        throws IOException
+    {
+        return super.createSubjectKeyIdentifier(SubjectPublicKeyInfoFactory.createSubjectPublicKeyInfo(publicKey));
+    }
+
+    private static class SHA1DigestCalculator
+        implements DigestCalculator
+    {
+        private ByteArrayOutputStream bOut = new ByteArrayOutputStream();
+
+        public AlgorithmIdentifier getAlgorithmIdentifier()
+        {
+            return new AlgorithmIdentifier(OIWObjectIdentifiers.idSHA1);
+        }
+
+        public OutputStream getOutputStream()
+        {
+            return bOut;
+        }
+
+        public byte[] getDigest()
+        {
+            byte[] bytes = bOut.toByteArray();
+
+            bOut.reset();
+
+            Digest sha1 = new SHA1Digest();
+
+            sha1.update(bytes, 0, bytes.length);
+
+            byte[] digest = new byte[sha1.getDigestSize()];
+
+            sha1.doFinal(digest, 0);
+
+            return digest;
+        }
+    }
+}