Separate getEskAndTag into two functions

Author: gefeili

pg/src/main/java/org/bouncycastle/openpgp/operator/PBEKeyEncryptionMethodGenerator.java

@@ -163,7 +163,7 @@ public byte[] getKey(int encAlgorithm)
 
     @Override
     public ContainedPacket generateV5(int kekAlgorithm, int aeadAlgorithm, byte[] sessionInfo)
-            throws PGPException
+        throws PGPException
     {
         return generate(kekAlgorithm, sessionInfo);
         // TODO: Implement v5 SKESK creation properly.
@@ -180,44 +180,46 @@ public ContainedPacket generateV6(int kekAlgorithm, int aeadAlgorithm, byte[] se
     // If we use this method, roundtripping v5 AEAD is broken.
     //  TODO: Investigate
     private ContainedPacket generateV5ESK(int kekAlgorithm, int aeadAlgorithm, byte[] sessionInfo)
-            throws PGPException
+        throws PGPException
     {
         byte[] ikm = getKey(kekAlgorithm);
-        byte[] info = new byte[] {
-                (byte) 0xC3,
-                (byte) SymmetricKeyEncSessionPacket.VERSION_5,
-                (byte) kekAlgorithm,
-                (byte) aeadAlgorithm
+        byte[] info = new byte[]{
+            (byte)0xC3,
+            (byte)SymmetricKeyEncSessionPacket.VERSION_5,
+            (byte)kekAlgorithm,
+            (byte)aeadAlgorithm
         };
 
         byte[] iv = new byte[AEADUtils.getIVLength(aeadAlgorithm)];
         random.nextBytes(iv);
 
         int tagLen = AEADUtils.getAuthTagLength(aeadAlgorithm);
-        byte[] eskAndTag = getEskAndTag(kekAlgorithm, aeadAlgorithm, sessionInfo, ikm, iv, info);
+        byte[] sessionKey = getSessionKey(sessionInfo);
+        byte[] eskAndTag = getEskAndTag(kekAlgorithm, aeadAlgorithm, sessionKey, ikm, iv, info);
         byte[] esk = Arrays.copyOfRange(eskAndTag, 0, eskAndTag.length - tagLen);
         byte[] tag = Arrays.copyOfRange(eskAndTag, esk.length, eskAndTag.length);
 
         return SymmetricKeyEncSessionPacket.createV5Packet(kekAlgorithm, aeadAlgorithm, iv, s2k, esk, tag);
     }
 
     private ContainedPacket generateV6ESK(int kekAlgorithm, int aeadAlgorithm, byte[] sessionInfo)
-            throws PGPException
+        throws PGPException
     {
         byte[] ikm = getKey(kekAlgorithm);
-        byte[] info = new byte[] {
-                (byte) 0xC3,
-                (byte) SymmetricKeyEncSessionPacket.VERSION_6,
-                (byte) kekAlgorithm,
-                (byte) aeadAlgorithm
+        byte[] info = new byte[]{
+            (byte)0xC3,
+            (byte)SymmetricKeyEncSessionPacket.VERSION_6,
+            (byte)kekAlgorithm,
+            (byte)aeadAlgorithm
         };
         byte[] kek = generateV6KEK(kekAlgorithm, ikm, info);
 
         byte[] iv = new byte[AEADUtils.getIVLength(aeadAlgorithm)];
         random.nextBytes(iv);
 
         int tagLen = AEADUtils.getAuthTagLength(aeadAlgorithm);
-        byte[] eskAndTag = getEskAndTag(kekAlgorithm, aeadAlgorithm, sessionInfo, kek, iv, info);
+        byte[] sessionKey = getSessionKey(sessionInfo);
+        byte[] eskAndTag = getEskAndTag(kekAlgorithm, aeadAlgorithm, sessionKey, ikm, iv, info);
         byte[] esk = Arrays.copyOfRange(eskAndTag, 0, eskAndTag.length - tagLen);
         byte[] tag = Arrays.copyOfRange(eskAndTag, esk.length, eskAndTag.length);
 
@@ -228,7 +230,7 @@ private ContainedPacket generateV6ESK(int kekAlgorithm, int aeadAlgorithm, byte[
      * Generate a V4 SKESK packet.
      *
      * @param encAlgorithm the {@link SymmetricKeyAlgorithmTags encryption algorithm} being used
-     * @param sessionInfo session data generated by the encrypted data generator.
+     * @param sessionInfo  session data generated by the encrypted data generator.
      * @return v4 SKESK packet
      * @throws PGPException
      */
@@ -251,10 +253,17 @@ public ContainedPacket generate(int encAlgorithm, byte[] sessionInfo)
         return SymmetricKeyEncSessionPacket.createV4Packet(encAlgorithm, s2k, encryptSessionInfo(encAlgorithm, key, nSessionInfo));
     }
 
+    protected byte[] getSessionKey(byte[] sessionInfo)
+    {
+        byte[] sessionKey = new byte[sessionInfo.length - 3];
+        System.arraycopy(sessionInfo, 1, sessionKey, 0, sessionKey.length);
+        return sessionKey;
+    }
+
     abstract protected byte[] encryptSessionInfo(int encAlgorithm, byte[] key, byte[] sessionInfo)
         throws PGPException;
 
-    abstract protected byte[] getEskAndTag(int kekAlgorithm, int aeadAlgorithm, byte[] sessionInfo, byte[] key, byte[] iv, byte[] info)
+    abstract protected byte[] getEskAndTag(int kekAlgorithm, int aeadAlgorithm, byte[] sessionKey, byte[] key, byte[] iv, byte[] info)
         throws PGPException;
 
     abstract protected byte[] generateV6KEK(int kekAlgorithm, byte[] ikm, byte[] info)

pg/src/main/java/org/bouncycastle/openpgp/operator/bc/BcPBEKeyEncryptionMethodGenerator.java

@@ -113,12 +113,9 @@ protected byte[] generateV6KEK(int kekAlgorithm, byte[] ikm, byte[] info)
         return BcAEADUtil.generateHKDFBytes(ikm, null, info, SymmetricKeyUtils.getKeyLengthInOctets(kekAlgorithm));
     }
 
-    protected byte[] getEskAndTag(int kekAlgorithm, int aeadAlgorithm, byte[] sessionInfo, byte[] key, byte[] iv, byte[] info)
+    protected byte[] getEskAndTag(int kekAlgorithm, int aeadAlgorithm, byte[] sessionKey, byte[] key, byte[] iv, byte[] info)
         throws PGPException
     {
-        byte[] sessionKey = new byte[sessionInfo.length - 3];
-        System.arraycopy(sessionInfo, 1, sessionKey, 0, sessionKey.length);
-
         AEADCipher aeadCipher = BcAEADUtil.createAEADCipher(kekAlgorithm, aeadAlgorithm);
         aeadCipher.init(true, new AEADParameters(new KeyParameter(key), 128, iv, info));
         int outLen = aeadCipher.getOutputSize(sessionKey.length);

pg/src/main/java/org/bouncycastle/openpgp/operator/jcajce/JcePBEKeyEncryptionMethodGenerator.java

@@ -151,12 +151,9 @@ protected byte[] generateV6KEK(int kekAlgorithm, byte[] ikm, byte[] info)
          return JceAEADUtil.generateHKDFBytes(ikm, null, info, SymmetricKeyUtils.getKeyLengthInOctets(kekAlgorithm));
      }
 
-     protected byte[] getEskAndTag(int kekAlgorithm, int aeadAlgorithm, byte[] sessionInfo, byte[] key, byte[] iv, byte[] info)
+     protected byte[] getEskAndTag(int kekAlgorithm, int aeadAlgorithm, byte[] sessionKey, byte[] key, byte[] iv, byte[] info)
          throws PGPException
      {
-         byte[] sessionKey = new byte[sessionInfo.length - 3];
-         System.arraycopy(sessionInfo, 1, sessionKey, 0, sessionKey.length);
-
          AEADCipher aeadCipher = BcAEADUtil.createAEADCipher(kekAlgorithm, aeadAlgorithm);
          aeadCipher.init(true, new AEADParameters(new KeyParameter(key), 128, iv, info));
          int outLen = aeadCipher.getOutputSize(sessionKey.length);