enabled use of MD5 in an S2K.

3 files changed, 96 insertions, 10 deletions

diff --git a/src/main/java/org/bouncycastle/openpgp/PGPSecretKey.java b/src/main/java/org/bouncycastle/openpgp/PGPSecretKey.java
index 0bab60ce..8ac0bd86 100644
--- a/src/main/java/org/bouncycastle/openpgp/PGPSecretKey.java
+++ b/src/main/java/org/bouncycastle/openpgp/PGPSecretKey.java
@@ -822,7 +822,7 @@ public class PGPSecretKey
                 byte[] encKey = newKeyEncryptor.getKey();
                 keyData = new byte[rawKeyData.length];
 
-                if (newKeyEncryptor.getS2K() != null)
+                if (newKeyEncryptor.getHashAlgorithm() != HashAlgorithmTags.MD5)
                 {
                     throw new PGPException("MD5 Digest Calculator required for version 3 key encryptor.");
                 }
diff --git a/src/main/java/org/bouncycastle/openpgp/operator/PBESecretKeyEncryptor.java b/src/main/java/org/bouncycastle/openpgp/operator/PBESecretKeyEncryptor.java
index a0d44570..0530638c 100644
--- a/src/main/java/org/bouncycastle/openpgp/operator/PBESecretKeyEncryptor.java
+++ b/src/main/java/org/bouncycastle/openpgp/operator/PBESecretKeyEncryptor.java
@@ -2,7 +2,6 @@ package org.bouncycastle.openpgp.operator;
 
 import java.security.SecureRandom;
 
-import org.bouncycastle.bcpg.HashAlgorithmTags;
 import org.bouncycastle.bcpg.S2K;
 import org.bouncycastle.openpgp.PGPException;
 
@@ -41,18 +40,19 @@ public abstract class PBESecretKeyEncryptor
         return encAlgorithm;
     }
 
-    public byte[] getKey()
-        throws PGPException
+    public int getHashAlgorithm()
     {
-        if (s2k == null && s2kDigestCalculator.getAlgorithm() != HashAlgorithmTags.MD5)
+        if (s2kDigestCalculator != null)
         {
-            byte[]        iv = new byte[8];
-
-            random.nextBytes(iv);
-
-            s2k = new S2K(s2kDigestCalculator.getAlgorithm(), iv, s2kCount);
+            return s2kDigestCalculator.getAlgorithm();
         }
 
+        return -1;
+    }
+
+    public byte[] getKey()
+        throws PGPException
+    {
         return PGPUtil.makeKeyFromPassPhrase(s2kDigestCalculator, encAlgorithm, s2k, passPhrase);
     }
 
@@ -61,9 +61,27 @@ public abstract class PBESecretKeyEncryptor
         return s2k;
     }
 
+    /**
+     * Key encryption method invoked for V4 keys and greater.
+     *
+     * @param keyData raw key data
+     * @param keyOff offset into rawe key data
+     * @param keyLen length of key data to use.
+     * @return an encryption of the passed in keyData.
+     * @throws PGPException on error in the underlying encryption process.
+     */
     public byte[] encryptKeyData(byte[] keyData, int keyOff, int keyLen)
         throws PGPException
     {
+        if (s2k == null)
+        {
+            byte[]        iv = new byte[8];
+
+            random.nextBytes(iv);
+
+            s2k = new S2K(s2kDigestCalculator.getAlgorithm(), iv, s2kCount);
+        }
+
         return encryptKeyData(getKey(), keyData, keyOff, keyLen);
     }
 
diff --git a/src/test/java/org/bouncycastle/openpgp/test/PGPKeyRingTest.java b/src/test/java/org/bouncycastle/openpgp/test/PGPKeyRingTest.java
index 8e044aff..d52f56ee 100644
--- a/src/test/java/org/bouncycastle/openpgp/test/PGPKeyRingTest.java
+++ b/src/test/java/org/bouncycastle/openpgp/test/PGPKeyRingTest.java
@@ -27,6 +27,7 @@ import org.bouncycastle.openpgp.PGPSecretKey;
 import org.bouncycastle.openpgp.PGPSecretKeyRing;
 import org.bouncycastle.openpgp.PGPSecretKeyRingCollection;
 import org.bouncycastle.openpgp.PGPSignature;
+import org.bouncycastle.openpgp.operator.PGPDigestCalculatorProvider;
 import org.bouncycastle.openpgp.operator.jcajce.JcaKeyFingerprintCalculator;
 import org.bouncycastle.openpgp.operator.jcajce.JcaPGPDigestCalculatorProviderBuilder;
 import org.bouncycastle.openpgp.operator.jcajce.JcePBESecretKeyDecryptorBuilder;
@@ -2354,6 +2355,72 @@ public class PGPKeyRingTest
         }
     }
 
+    private void rewrapTestMD5()
+        throws Exception
+    {
+        // Read the secret key rings
+        PGPSecretKeyRingCollection privRings = new PGPSecretKeyRingCollection(
+                                                         new ByteArrayInputStream(rewrapKey));
+        char[] newPass = "fred".toCharArray();
+
+        Iterator rIt = privRings.getKeyRings();
+
+        if (rIt.hasNext())
+        {
+            PGPSecretKeyRing pgpPriv= (PGPSecretKeyRing)rIt.next();
+
+            Iterator it = pgpPriv.getSecretKeys();
+
+            PGPDigestCalculatorProvider calcProvider = new JcaPGPDigestCalculatorProviderBuilder().setProvider("BC").build();
+
+            while (it.hasNext())
+            {
+                PGPSecretKey pgpKey = (PGPSecretKey)it.next();
+                long oldKeyID = pgpKey.getKeyID();
+
+                // re-encrypt the key with an empty password
+                pgpPriv = PGPSecretKeyRing.removeSecretKey(pgpPriv, pgpKey);
+                pgpKey = PGPSecretKey.copyWithNewPassword(
+                                    pgpKey,
+                                    new JcePBESecretKeyDecryptorBuilder(calcProvider).setProvider("BC").build(rewrapPass),
+                                    null);
+                pgpPriv = PGPSecretKeyRing.insertSecretKey(pgpPriv, pgpKey);
+
+                // this should succeed
+                PGPPrivateKey privTmp = pgpKey.extractPrivateKey(null);
+
+                if (pgpKey.getKeyID() != oldKeyID)
+                {
+                    fail("key ID mismatch");
+                }
+            }
+
+            it = pgpPriv.getSecretKeys();
+
+            while (it.hasNext())
+            {
+                PGPSecretKey pgpKey = (PGPSecretKey)it.next();
+                long oldKeyID = pgpKey.getKeyID();
+
+                // re-encrypt the key with an empty password
+                pgpPriv = PGPSecretKeyRing.removeSecretKey(pgpPriv, pgpKey);
+                pgpKey = PGPSecretKey.copyWithNewPassword(
+                                    pgpKey,
+                                    null,
+                                    new JcePBESecretKeyEncryptorBuilder(SymmetricKeyAlgorithmTags.CAST5, calcProvider.get(HashAlgorithmTags.MD5)).setProvider("BC").build(newPass));
+                pgpPriv = PGPSecretKeyRing.insertSecretKey(pgpPriv, pgpKey);
+
+                // this should succeed
+                PGPPrivateKey privTmp = pgpKey.extractPrivateKey(new JcePBESecretKeyDecryptorBuilder(calcProvider).setProvider("BC").build(newPass));
+
+                if (pgpKey.getKeyID() != oldKeyID)
+                {
+                    fail("key ID mismatch");
+                }
+            }
+        }
+    }
+
     private void testPublicKeyRingWithX509()
         throws Exception
     {
@@ -2508,6 +2575,7 @@ public class PGPKeyRingTest
             generateSha1Test();
             rewrapTest();
             rewrapTestV3();
+            rewrapTestMD5();
             testPublicKeyRingWithX509();
             testSecretKeyRingWithPersonalCertificate();
             insertMasterTest();