1 files changed, 144 insertions, 0 deletions
diff --git a/libraries/spongycastle/pkix/src/main/java/org/spongycastle/operator/bc/BcContentVerifierProviderBuilder.java b/libraries/spongycastle/pkix/src/main/java/org/spongycastle/operator/bc/BcContentVerifierProviderBuilder.java
new file mode 100644
index 000000000..3b975e4fa
--- /dev/null
+++ b/libraries/spongycastle/pkix/src/main/java/org/spongycastle/operator/bc/BcContentVerifierProviderBuilder.java
@@ -0,0 +1,144 @@
+package org.spongycastle.operator.bc;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+import org.spongycastle.asn1.x509.AlgorithmIdentifier;
+import org.spongycastle.asn1.x509.SubjectPublicKeyInfo;
+import org.spongycastle.cert.X509CertificateHolder;
+import org.spongycastle.crypto.Signer;
+import org.spongycastle.crypto.params.AsymmetricKeyParameter;
+import org.spongycastle.operator.ContentVerifier;
+import org.spongycastle.operator.ContentVerifierProvider;
+import org.spongycastle.operator.OperatorCreationException;
+
+public abstract class BcContentVerifierProviderBuilder
+{
+    protected BcDigestProvider digestProvider;
+
+    public BcContentVerifierProviderBuilder()
+    {
+        this.digestProvider = BcDefaultDigestProvider.INSTANCE;
+    }
+
+    public ContentVerifierProvider build(final X509CertificateHolder certHolder)
+        throws OperatorCreationException
+    {
+        return new ContentVerifierProvider()
+        {
+            public boolean hasAssociatedCertificate()
+            {
+                return true;
+            }
+
+            public X509CertificateHolder getAssociatedCertificate()
+            {
+                return certHolder;
+            }
+
+            public ContentVerifier get(AlgorithmIdentifier algorithm)
+                throws OperatorCreationException
+            {
+                try
+                {
+                    AsymmetricKeyParameter publicKey = extractKeyParameters(certHolder.getSubjectPublicKeyInfo());
+                    BcSignerOutputStream stream = createSignatureStream(algorithm, publicKey);
+
+                    return new SigVerifier(algorithm, stream);
+                }
+                catch (IOException e)
+                {
+                    throw new OperatorCreationException("exception on setup: " + e, e);
+                }
+            }
+        };
+    }
+
+    public ContentVerifierProvider build(final AsymmetricKeyParameter publicKey)
+        throws OperatorCreationException
+    {
+        return new ContentVerifierProvider()
+        {
+            public boolean hasAssociatedCertificate()
+            {
+                return false;
+            }
+
+            public X509CertificateHolder getAssociatedCertificate()
+            {
+                return null;
+            }
+
+            public ContentVerifier get(AlgorithmIdentifier algorithm)
+                throws OperatorCreationException
+            {
+                BcSignerOutputStream stream = createSignatureStream(algorithm, publicKey);
+
+                return new SigVerifier(algorithm, stream);
+            }
+        };
+    }
+
+    private BcSignerOutputStream createSignatureStream(AlgorithmIdentifier algorithm, AsymmetricKeyParameter publicKey)
+        throws OperatorCreationException
+    {
+        Signer sig = createSigner(algorithm);
+
+        sig.init(false, publicKey);
+
+        return new BcSignerOutputStream(sig);
+    }
+
+    /**
+     * Extract an AsymmetricKeyParameter from the passed in SubjectPublicKeyInfo structure.
+     *
+     * @param publicKeyInfo a publicKeyInfo structure describing the public key required.
+     * @return an AsymmetricKeyParameter object containing the appropriate public key.
+     * @throws IOException if the publicKeyInfo data cannot be parsed,
+     */
+    protected abstract AsymmetricKeyParameter extractKeyParameters(SubjectPublicKeyInfo publicKeyInfo)
+        throws IOException;
+
+    /**
+     * Create the correct signer for the algorithm identifier sigAlgId.
+     *
+     * @param sigAlgId the algorithm details for the signature we want to verify.
+     * @return a Signer object.
+     * @throws OperatorCreationException if the Signer cannot be constructed.
+     */
+    protected abstract Signer createSigner(AlgorithmIdentifier sigAlgId)
+        throws OperatorCreationException;
+
+    private class SigVerifier
+        implements ContentVerifier
+    {
+        private BcSignerOutputStream stream;
+        private AlgorithmIdentifier algorithm;
+
+        SigVerifier(AlgorithmIdentifier algorithm, BcSignerOutputStream stream)
+        {
+            this.algorithm = algorithm;
+            this.stream = stream;
+        }
+
+        public AlgorithmIdentifier getAlgorithmIdentifier()
+        {
+            return algorithm;
+        }
+
+        public OutputStream getOutputStream()
+        {
+            if (stream == null)
+            {
+                throw new IllegalStateException("verifier not initialised");
+            }
+
+            return stream;
+        }
+
+        public boolean verify(byte[] expected)
+        {
+            return stream.verify(expected);
+        }
+    }
+}
+\ No newline at end of file