1 files changed, 19 insertions, 50 deletions

diff --git a/core/src/main/java/org/bouncycastle/crypto/io/CipherInputStream.java b/core/src/main/java/org/bouncycastle/crypto/io/CipherInputStream.java
index f80add1a..11cd903b 100644
--- a/core/src/main/java/org/bouncycastle/crypto/io/CipherInputStream.java
+++ b/core/src/main/java/org/bouncycastle/crypto/io/CipherInputStream.java
@@ -12,28 +12,28 @@ import org.bouncycastle.crypto.modes.AEADBlockCipher;
 /**
  * A CipherInputStream is composed of an InputStream and a cipher so that read() methods return data
  * that are read in from the underlying InputStream but have been additionally processed by the
- * cipher. The cipher must be fully initialized before being used by a CipherInputStream.
- * <p/>
- * For example, if the cipher is initialized for decryption, the
+ * Cipher. The cipher must be fully initialized before being used by a CipherInputStream.
+ * <p>
+ * For example, if the Cipher is initialized for decryption, the
  * CipherInputStream will attempt to read in data and decrypt them,
  * before returning the decrypted data.
  */
 public class CipherInputStream
     extends FilterInputStream
 {
-    private static final int INPUT_BUF_SIZE = 2048;
-
     private BufferedBlockCipher bufferedBlockCipher;
     private StreamCipher streamCipher;
     private AEADBlockCipher aeadBlockCipher;
 
-    private byte[] buf;
-    private final byte[] inBuf = new byte[INPUT_BUF_SIZE];
+    private final byte[] buf;
+    private final byte[] inBuf;
 
     private int bufOff;
     private int maxBuf;
     private boolean finalized;
 
+    private static final int INPUT_BUF_SIZE = 2048;
+
     /**
      * Constructs a CipherInputStream from an InputStream and a
      * BufferedBlockCipher.
@@ -45,6 +45,9 @@ public class CipherInputStream
         super(is);
 
         this.bufferedBlockCipher = cipher;
+
+        buf = new byte[cipher.getOutputSize(INPUT_BUF_SIZE)];
+        inBuf = new byte[INPUT_BUF_SIZE];
     }
 
     public CipherInputStream(
@@ -54,6 +57,9 @@ public class CipherInputStream
         super(is);
 
         this.streamCipher = cipher;
+
+        buf = new byte[INPUT_BUF_SIZE];
+        inBuf = new byte[INPUT_BUF_SIZE];
     }
 
     /**
@@ -64,6 +70,9 @@ public class CipherInputStream
         super(is);
 
         this.aeadBlockCipher = cipher;
+
+        buf = new byte[cipher.getOutputSize(INPUT_BUF_SIZE)];
+        inBuf = new byte[INPUT_BUF_SIZE];
     }
 
     /**
@@ -99,7 +108,6 @@ public class CipherInputStream
 
             try
             {
-                ensureCapacity(read, false);
                 if (bufferedBlockCipher != null)
                 {
                     maxBuf = bufferedBlockCipher.processBytes(inBuf, 0, read, buf, 0);
@@ -116,7 +124,7 @@ public class CipherInputStream
             }
             catch (Exception e)
             {
-                throw new CipherIOException("Error processing stream ", e);
+                throw new IOException("Error processing stream " + e);
             }
         }
         return maxBuf;
@@ -128,7 +136,6 @@ public class CipherInputStream
         try
         {
             finalized = true;
-            ensureCapacity(0, true);
             if (bufferedBlockCipher != null)
             {
                 maxBuf = bufferedBlockCipher.doFinal(buf, 0);
@@ -148,7 +155,7 @@ public class CipherInputStream
         }
         catch (Exception e)
         {
-            throw new CipherIOException("Error finalising cipher ", e);
+            throw new IOException("Error finalising cipher " + e);
         }
     }
 
@@ -252,49 +259,11 @@ public class CipherInputStream
     }
 
     /**
-     * Ensure the ciphertext buffer has space sufficient to accept an upcoming output.
-     *
-     * @param updateSize the size of the pending update.
-     * @param <code>true</code> iff this the cipher is to be finalised.
-     */
-    private void ensureCapacity(int updateSize, boolean finalOutput)
-    {
-        int bufLen = updateSize;
-        if (finalOutput)
-        {
-            if (bufferedBlockCipher != null)
-            {
-                bufLen = bufferedBlockCipher.getOutputSize(updateSize);
-            }
-            else if (aeadBlockCipher != null)
-            {
-                bufLen = aeadBlockCipher.getOutputSize(updateSize);
-            }
-        }
-        else
-        {
-            if (bufferedBlockCipher != null)
-            {
-                bufLen = bufferedBlockCipher.getUpdateOutputSize(updateSize);
-            }
-            else if (aeadBlockCipher != null)
-            {
-                bufLen = aeadBlockCipher.getUpdateOutputSize(updateSize);
-            }
-        }
-
-        if ((buf == null) || (buf.length < bufLen))
-        {
-            buf = new byte[bufLen];
-        }
-    }
-
-    /**
      * Closes the underlying input stream and finalises the processing of the data by the cipher.
      *
      * @throws IOException if there was an error closing the input stream.
      * @throws InvalidCipherTextIOException if the data read from the stream was invalid ciphertext
-     *             (e.g. the cipher is an AEAD cipher and the ciphertext tag check fails).
+     * (e.g. the cipher is an AEAD cipher and the ciphertext tag check fails).
      */
     public void close()
         throws IOException