1 files changed, 124 insertions, 0 deletions
diff --git a/libraries/spongycastle/pkix/src/main/java/org/spongycastle/cms/bc/BcCMSContentEncryptorBuilder.java b/libraries/spongycastle/pkix/src/main/java/org/spongycastle/cms/bc/BcCMSContentEncryptorBuilder.java
new file mode 100644
index 000000000..22f79fb77
--- /dev/null
+++ b/libraries/spongycastle/pkix/src/main/java/org/spongycastle/cms/bc/BcCMSContentEncryptorBuilder.java
@@ -0,0 +1,124 @@
+package org.spongycastle.cms.bc;
+
+import java.io.OutputStream;
+import java.security.SecureRandom;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.spongycastle.asn1.ASN1ObjectIdentifier;
+import org.spongycastle.asn1.x509.AlgorithmIdentifier;
+import org.spongycastle.cms.CMSAlgorithm;
+import org.spongycastle.cms.CMSException;
+import org.spongycastle.crypto.BufferedBlockCipher;
+import org.spongycastle.crypto.CipherKeyGenerator;
+import org.spongycastle.crypto.StreamCipher;
+import org.spongycastle.crypto.io.CipherOutputStream;
+import org.spongycastle.crypto.params.KeyParameter;
+import org.spongycastle.operator.GenericKey;
+import org.spongycastle.operator.OutputEncryptor;
+import org.spongycastle.util.Integers;
+
+public class BcCMSContentEncryptorBuilder
+{
+    private static Map keySizes = new HashMap();
+
+    static
+    {
+        keySizes.put(CMSAlgorithm.AES128_CBC, Integers.valueOf(128));
+        keySizes.put(CMSAlgorithm.AES192_CBC, Integers.valueOf(192));
+        keySizes.put(CMSAlgorithm.AES256_CBC, Integers.valueOf(256));
+
+        keySizes.put(CMSAlgorithm.CAMELLIA128_CBC, Integers.valueOf(128));
+        keySizes.put(CMSAlgorithm.CAMELLIA192_CBC, Integers.valueOf(192));
+        keySizes.put(CMSAlgorithm.CAMELLIA256_CBC, Integers.valueOf(256));
+    }
+
+    private static int getKeySize(ASN1ObjectIdentifier oid)
+    {
+        Integer size = (Integer)keySizes.get(oid);
+
+        if (size != null)
+        {
+            return size.intValue();
+        }
+
+        return -1;
+    }
+
+    private final ASN1ObjectIdentifier encryptionOID;
+    private final int                  keySize;
+
+    private EnvelopedDataHelper helper = new EnvelopedDataHelper();
+    private SecureRandom random;
+
+    public BcCMSContentEncryptorBuilder(ASN1ObjectIdentifier encryptionOID)
+    {
+        this(encryptionOID, getKeySize(encryptionOID));
+    }
+
+    public BcCMSContentEncryptorBuilder(ASN1ObjectIdentifier encryptionOID, int keySize)
+    {
+        this.encryptionOID = encryptionOID;
+        this.keySize = keySize;
+    }
+
+    public BcCMSContentEncryptorBuilder setSecureRandom(SecureRandom random)
+    {
+        this.random = random;
+
+        return this;
+    }
+
+    public OutputEncryptor build()
+        throws CMSException
+    {
+        return new CMSOutputEncryptor(encryptionOID, keySize, random);
+    }
+
+    private class CMSOutputEncryptor
+        implements OutputEncryptor
+    {
+        private KeyParameter encKey;
+        private AlgorithmIdentifier algorithmIdentifier;
+        private Object             cipher;
+
+        CMSOutputEncryptor(ASN1ObjectIdentifier encryptionOID, int keySize, SecureRandom random)
+            throws CMSException
+        {
+            if (random == null)
+            {
+                random = new SecureRandom();
+            }
+
+            CipherKeyGenerator keyGen = helper.createKeyGenerator(encryptionOID, random);
+
+            encKey = new KeyParameter(keyGen.generateKey());
+
+            algorithmIdentifier = helper.generateAlgorithmIdentifier(encryptionOID, encKey, random);
+
+            cipher = helper.createContentCipher(true, encKey, algorithmIdentifier);
+        }
+
+        public AlgorithmIdentifier getAlgorithmIdentifier()
+        {
+            return algorithmIdentifier;
+        }
+
+        public OutputStream getOutputStream(OutputStream dOut)
+        {
+            if (cipher instanceof BufferedBlockCipher)
+            {
+                return new CipherOutputStream(dOut, (BufferedBlockCipher)cipher);
+            }
+            else
+            {
+                return new CipherOutputStream(dOut, (StreamCipher)cipher);
+            }
+        }
+
+        public GenericKey getKey()
+        {
+            return new GenericKey(algorithmIdentifier, encKey.getKey());
+        }
+    }
+}