1 files changed, 57 insertions, 0 deletions
diff --git a/pg/src/main/java/org/spongycastle/openpgp/operator/PBEDataDecryptorFactory.java b/pg/src/main/java/org/spongycastle/openpgp/operator/PBEDataDecryptorFactory.java
new file mode 100644
index 00000000..5660468e
--- /dev/null
+++ b/pg/src/main/java/org/spongycastle/openpgp/operator/PBEDataDecryptorFactory.java
@@ -0,0 +1,57 @@
+package org.spongycastle.openpgp.operator;
+
+import org.spongycastle.bcpg.S2K;
+import org.spongycastle.bcpg.SymmetricKeyAlgorithmTags;
+import org.spongycastle.openpgp.PGPException;
+
+/**
+ * A factory for performing PBE decryption operations.
+ */
+public abstract class PBEDataDecryptorFactory
+    implements PGPDataDecryptorFactory
+{
+    private char[] passPhrase;
+    private PGPDigestCalculatorProvider calculatorProvider;
+
+    /**
+     * Construct a PBE data decryptor factory.
+     *
+     * @param passPhrase the pass phrase to generate decryption keys with.
+     * @param calculatorProvider the digest to use in key generation.
+     */
+    protected PBEDataDecryptorFactory(char[] passPhrase, PGPDigestCalculatorProvider calculatorProvider)
+    {
+        this.passPhrase = passPhrase;
+        this.calculatorProvider = calculatorProvider;
+    }
+
+    /**
+     * Generates an encryption key using the pass phrase and digest calculator configured for this
+     * factory.
+     *
+     * @param keyAlgorithm the {@link SymmetricKeyAlgorithmTags encryption algorithm} to generate a
+     *            key for.
+     * @param s2k the string-to-key specification to use to generate the key.
+     * @return the key bytes for the encryption algorithm, generated using the pass phrase of this
+     *         factory.
+     * @throws PGPException if an error occurs generating the key.
+     */
+    public byte[] makeKeyFromPassPhrase(int keyAlgorithm, S2K s2k)
+        throws PGPException
+    {
+        return PGPUtil.makeKeyFromPassPhrase(calculatorProvider, keyAlgorithm, s2k, passPhrase);
+    }
+
+    /**
+     * Decrypts session data from an encrypted data packet.
+     *
+     * @param keyAlgorithm the {@link SymmetricKeyAlgorithmTags encryption algorithm} used to
+     *            encrypt the session data.
+     * @param key the key bytes for the encryption algorithm.
+     * @param seckKeyData the encrypted session data to decrypt.
+     * @return the decrypted session data.
+     * @throws PGPException if an error occurs decrypting the session data.
+     */
+    public abstract byte[] recoverSessionData(int keyAlgorithm, byte[] key, byte[] seckKeyData)
+        throws PGPException;
+}