1 files changed, 155 insertions, 0 deletions
diff --git a/pg/src/main/java/org/spongycastle/openpgp/examples/PGPExampleUtil.java b/pg/src/main/java/org/spongycastle/openpgp/examples/PGPExampleUtil.java
new file mode 100644
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+++ b/pg/src/main/java/org/spongycastle/openpgp/examples/PGPExampleUtil.java
@@ -0,0 +1,155 @@
+package org.spongycastle.openpgp.examples;
+
+import java.io.BufferedInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.security.NoSuchProviderException;
+import java.util.Iterator;
+
+import org.spongycastle.openpgp.PGPCompressedDataGenerator;
+import org.spongycastle.openpgp.PGPException;
+import org.spongycastle.openpgp.PGPLiteralData;
+import org.spongycastle.openpgp.PGPPrivateKey;
+import org.spongycastle.openpgp.PGPPublicKey;
+import org.spongycastle.openpgp.PGPPublicKeyRing;
+import org.spongycastle.openpgp.PGPPublicKeyRingCollection;
+import org.spongycastle.openpgp.PGPSecretKey;
+import org.spongycastle.openpgp.PGPSecretKeyRing;
+import org.spongycastle.openpgp.PGPSecretKeyRingCollection;
+import org.spongycastle.openpgp.PGPUtil;
+import org.spongycastle.openpgp.operator.jcajce.JcaKeyFingerprintCalculator;
+import org.spongycastle.openpgp.operator.jcajce.JcePBESecretKeyDecryptorBuilder;
+
+class PGPExampleUtil
+{
+    static byte[] compressFile(String fileName, int algorithm) throws IOException
+    {
+        ByteArrayOutputStream bOut = new ByteArrayOutputStream();
+        PGPCompressedDataGenerator comData = new PGPCompressedDataGenerator(algorithm);
+        PGPUtil.writeFileToLiteralData(comData.open(bOut), PGPLiteralData.BINARY,
+            new File(fileName));
+        comData.close();
+        return bOut.toByteArray();
+    }
+
+    /**
+     * Search a secret key ring collection for a secret key corresponding to keyID if it
+     * exists.
+     * 
+     * @param pgpSec a secret key ring collection.
+     * @param keyID keyID we want.
+     * @param pass passphrase to decrypt secret key with.
+     * @return the private key.
+     * @throws PGPException
+     * @throws NoSuchProviderException
+     */
+    static PGPPrivateKey findSecretKey(PGPSecretKeyRingCollection pgpSec, long keyID, char[] pass)
+        throws PGPException, NoSuchProviderException
+    {
+        PGPSecretKey pgpSecKey = pgpSec.getSecretKey(keyID);
+
+        if (pgpSecKey == null)
+        {
+            return null;
+        }
+
+        return pgpSecKey.extractPrivateKey(new JcePBESecretKeyDecryptorBuilder().setProvider("SC").build(pass));
+    }
+
+    static PGPPublicKey readPublicKey(String fileName) throws IOException, PGPException
+    {
+        InputStream keyIn = new BufferedInputStream(new FileInputStream(fileName));
+        PGPPublicKey pubKey = readPublicKey(keyIn);
+        keyIn.close();
+        return pubKey;
+    }
+
+    /**
+     * A simple routine that opens a key ring file and loads the first available key
+     * suitable for encryption.
+     * 
+     * @param input data stream containing the public key data
+     * @return the first public key found.
+     * @throws IOException
+     * @throws PGPException
+     */
+    static PGPPublicKey readPublicKey(InputStream input) throws IOException, PGPException
+    {
+        PGPPublicKeyRingCollection pgpPub = new PGPPublicKeyRingCollection(
+            PGPUtil.getDecoderStream(input), new JcaKeyFingerprintCalculator());
+
+        //
+        // we just loop through the collection till we find a key suitable for encryption, in the real
+        // world you would probably want to be a bit smarter about this.
+        //
+
+        Iterator keyRingIter = pgpPub.getKeyRings();
+        while (keyRingIter.hasNext())
+        {
+            PGPPublicKeyRing keyRing = (PGPPublicKeyRing)keyRingIter.next();
+
+            Iterator keyIter = keyRing.getPublicKeys();
+            while (keyIter.hasNext())
+            {
+                PGPPublicKey key = (PGPPublicKey)keyIter.next();
+
+                if (key.isEncryptionKey())
+                {
+                    return key;
+                }
+            }
+        }
+
+        throw new IllegalArgumentException("Can't find encryption key in key ring.");
+    }
+
+    static PGPSecretKey readSecretKey(String fileName) throws IOException, PGPException
+    {
+        InputStream keyIn = new BufferedInputStream(new FileInputStream(fileName));
+        PGPSecretKey secKey = readSecretKey(keyIn);
+        keyIn.close();
+        return secKey;
+    }
+
+    /**
+     * A simple routine that opens a key ring file and loads the first available key
+     * suitable for signature generation.
+     * 
+     * @param input stream to read the secret key ring collection from.
+     * @return a secret key.
+     * @throws IOException on a problem with using the input stream.
+     * @throws PGPException if there is an issue parsing the input stream.
+     */
+    static PGPSecretKey readSecretKey(InputStream input) throws IOException, PGPException
+    {
+        PGPSecretKeyRingCollection pgpSec = new PGPSecretKeyRingCollection(
+            PGPUtil.getDecoderStream(input), new JcaKeyFingerprintCalculator());
+
+        //
+        // we just loop through the collection till we find a key suitable for encryption, in the real
+        // world you would probably want to be a bit smarter about this.
+        //
+
+        Iterator keyRingIter = pgpSec.getKeyRings();
+        while (keyRingIter.hasNext())
+        {
+            PGPSecretKeyRing keyRing = (PGPSecretKeyRing)keyRingIter.next();
+
+            Iterator keyIter = keyRing.getSecretKeys();
+            while (keyIter.hasNext())
+            {
+                PGPSecretKey key = (PGPSecretKey)keyIter.next();
+
+                if (key.isSigningKey())
+                {
+                    return key;
+                }
+            }
+        }
+
+        throw new IllegalArgumentException("Can't find signing key in key ring.");
+    }
+}