Simplify: in practice, AAD is always either the hash array or `null…

…`, never a `ByteBuffer` or a sub-array
jchambers · Mar 3, 2024 · 2b09344 · 2b09344
1 parent 0edd2e0
commit 2b09344
Show file tree

Hide file tree

Showing 6 changed files with 30 additions and 82 deletions.
diff --git a/src/main/java/com/eatthepath/noise/CipherState.java b/src/main/java/com/eatthepath/noise/CipherState.java
@@ -39,7 +39,7 @@ public boolean hasKey() {
     return this.key != null;
   }
 
-  public ByteBuffer decrypt(@Nullable final ByteBuffer associatedData, final ByteBuffer ciphertext)
+  public ByteBuffer decrypt(@Nullable final byte[] associatedData, final ByteBuffer ciphertext)
       throws AEADBadTagException {
 
     final ByteBuffer plaintext = ByteBuffer.allocate(getPlaintextLength(ciphertext.remaining()));
@@ -54,7 +54,7 @@ public ByteBuffer decrypt(@Nullable final ByteBuffer associatedData, final ByteB
     return plaintext.flip();
   }
 
-  public int decrypt(@Nullable final ByteBuffer associatedData, final ByteBuffer ciphertext, final ByteBuffer plaintext)
+  public int decrypt(@Nullable final byte[] associatedData, final ByteBuffer ciphertext, final ByteBuffer plaintext)
       throws AEADBadTagException, ShortBufferException {
 
     if (hasKey()) {
@@ -75,8 +75,6 @@ public byte[] decrypt(@Nullable final byte[] associatedData, final byte[] cipher
 
     try {
       decrypt(associatedData,
-          0,
-          associatedData != null ? associatedData.length : 0,
           ciphertext,
           0,
           ciphertext.length,
@@ -91,8 +89,6 @@ public byte[] decrypt(@Nullable final byte[] associatedData, final byte[] cipher
   }
 
   public int decrypt(@Nullable final byte[] associatedData,
-                     final int aadOffset,
-                     final int aadLength,
                      final byte[] ciphertext,
                      final int ciphertextOffset,
                      final int ciphertextLength,
@@ -103,8 +99,6 @@ public int decrypt(@Nullable final byte[] associatedData,
       final int plaintextLength = cipher.decrypt(key,
           nonce,
           associatedData,
-          aadOffset,
-          aadLength,
           ciphertext,
           ciphertextOffset,
           ciphertextLength,
@@ -119,7 +113,7 @@ public int decrypt(@Nullable final byte[] associatedData,
     }
   }
 
-  public ByteBuffer encrypt(@Nullable final ByteBuffer associatedData, final ByteBuffer plaintext) {
+  public ByteBuffer encrypt(@Nullable final byte[] associatedData, final ByteBuffer plaintext) {
     final ByteBuffer ciphertext = ByteBuffer.allocate(getCiphertextLength(plaintext.remaining()));
 
     try {
@@ -132,7 +126,7 @@ public ByteBuffer encrypt(@Nullable final ByteBuffer associatedData, final ByteB
     return ciphertext.flip();
   }
 
-  public int encrypt(@Nullable final ByteBuffer associatedData, final ByteBuffer plaintext, final ByteBuffer ciphertext) throws ShortBufferException {
+  public int encrypt(@Nullable final byte[] associatedData, final ByteBuffer plaintext, final ByteBuffer ciphertext) throws ShortBufferException {
     if (hasKey()) {
       final int ciphertextLength = cipher.encrypt(key, nonce, associatedData, plaintext, ciphertext);
       nonce += 1;
@@ -151,8 +145,6 @@ public byte[] encrypt(@Nullable final byte[] associatedData, final byte[] plaint
 
     try {
       encrypt(associatedData,
-          0,
-          associatedData != null ? associatedData.length : 0,
           plaintext,
           0,
           plaintext.length,
@@ -167,8 +159,6 @@ public byte[] encrypt(@Nullable final byte[] associatedData, final byte[] plaint
   }
 
   public int encrypt(@Nullable final byte[] associatedData,
-                       final int aadOffset,
-                       final int aadLength,
                        final byte[] plaintext,
                        final int plaintextOffset,
                        final int plaintextLength,
@@ -179,8 +169,6 @@ public int encrypt(@Nullable final byte[] associatedData,
       final int ciphertextLength = cipher.encrypt(key,
           nonce,
           associatedData,
-          aadOffset,
-          aadLength,
           plaintext,
           plaintextOffset,
           plaintextLength,

diff --git a/src/main/java/com/eatthepath/noise/NoiseHandshake.java b/src/main/java/com/eatthepath/noise/NoiseHandshake.java
@@ -418,15 +418,15 @@ private int encryptAndHash(final byte[] plaintext,
                              final int ciphertextOffset) throws ShortBufferException {
 
     final int ciphertextLength =
-        cipherState.encrypt(hash, 0, hash.length, plaintext, plaintextOffset, plaintextLength, ciphertext, ciphertextOffset);
+        cipherState.encrypt(hash, plaintext, plaintextOffset, plaintextLength, ciphertext, ciphertextOffset);
 
     mixHash(ciphertext, ciphertextOffset, ciphertextLength);
 
     return ciphertextLength;
   }
 
   private int encryptAndHash(final ByteBuffer plaintext, final ByteBuffer ciphertext) throws ShortBufferException {
-    final int ciphertextLength = cipherState.encrypt(ByteBuffer.wrap(hash), plaintext, ciphertext);
+    final int ciphertextLength = cipherState.encrypt(hash, plaintext, ciphertext);
 
     mixHash(ciphertext.slice(ciphertext.position() - ciphertextLength, ciphertextLength));
 
@@ -440,7 +440,7 @@ private int decryptAndHash(final byte[] ciphertext,
                              final int plaintextOffset) throws ShortBufferException, AEADBadTagException {
 
     final int plaintextLength =
-        cipherState.decrypt(hash, 0, hash.length, ciphertext, ciphertextOffset, ciphertextLength, plaintext, plaintextOffset);
+        cipherState.decrypt(hash, ciphertext, ciphertextOffset, ciphertextLength, plaintext, plaintextOffset);
 
     mixHash(ciphertext, ciphertextOffset, ciphertextLength);
 
@@ -451,7 +451,7 @@ private int decryptAndHash(final ByteBuffer ciphertext,
                              final ByteBuffer plaintext) throws ShortBufferException, AEADBadTagException {
 
     final int initialCiphertextPosition = ciphertext.position();
-    final int plaintextLength = cipherState.decrypt(ByteBuffer.wrap(hash), ciphertext, plaintext);
+    final int plaintextLength = cipherState.decrypt(hash, ciphertext, plaintext);
 
     mixHash(ciphertext.slice(initialCiphertextPosition, ciphertext.position() - initialCiphertextPosition));
 

diff --git a/src/main/java/com/eatthepath/noise/NoiseTransportImpl.java b/src/main/java/com/eatthepath/noise/NoiseTransportImpl.java
@@ -64,7 +64,7 @@ public int readMessage(final byte[] ciphertext,
       throw new ShortBufferException("Plaintext array after offset is not large enough to hold plaintext");
     }
 
-    return readerState.decrypt(null, 0, 0,
+    return readerState.decrypt(null,
         ciphertext, ciphertextOffset, ciphertextLength,
         plaintext, plaintextOffset);
   }
@@ -113,7 +113,7 @@ public int writeMessage(final byte[] plaintext,
       throw new ShortBufferException("Ciphertext array after offset is not large enough to hold ciphertext");
     }
 
-    return writerState.encrypt(null, 0, 0,
+    return writerState.encrypt(null,
         plaintext, plaintextOffset, plaintextLength,
         ciphertext, ciphertextOffset);
   }

diff --git a/src/main/java/com/eatthepath/noise/component/AbstractNoiseCipher.java b/src/main/java/com/eatthepath/noise/component/AbstractNoiseCipher.java
@@ -26,17 +26,14 @@ private interface CipherFinalizer<T> {
   @Override
   public int encrypt(final Key key,
                      final long nonce,
-                     @Nullable final ByteBuffer associatedData,
+                     @Nullable final byte[] associatedData,
                      final ByteBuffer plaintext,
                      final ByteBuffer ciphertext) throws ShortBufferException {
 
     initCipher(cipher, Cipher.ENCRYPT_MODE, key, nonce);
 
     if (associatedData != null) {
-      final byte[] adBytes = new byte[associatedData.remaining()];
-      associatedData.get(adBytes);
-
-      cipher.updateAAD(adBytes);
+      cipher.updateAAD(associatedData);
     }
 
     return finishEncryption(() -> cipher.doFinal(plaintext, ciphertext));
@@ -46,8 +43,6 @@ public int encrypt(final Key key,
   public int encrypt(final Key key,
                      final long nonce,
                      @Nullable final byte[] associatedData,
-                     final int aadOffset,
-                     final int aadLength,
                      final byte[] plaintext,
                      final int plaintextOffset,
                      final int plaintextLength,
@@ -57,7 +52,7 @@ public int encrypt(final Key key,
     initCipher(cipher, Cipher.ENCRYPT_MODE, key, nonce);
 
     if (associatedData != null) {
-      cipher.updateAAD(associatedData, aadOffset, aadLength);
+      cipher.updateAAD(associatedData);
     }
 
     return finishEncryption(() ->
@@ -67,17 +62,14 @@ public int encrypt(final Key key,
   @Override
   public int decrypt(final Key key,
                      final long nonce,
-                     @Nullable final ByteBuffer associatedData,
+                     @Nullable final byte[] associatedData,
                      final ByteBuffer ciphertext,
                      final ByteBuffer plaintext) throws AEADBadTagException, ShortBufferException {
 
     initCipher(cipher, Cipher.DECRYPT_MODE, key, nonce);
 
     if (associatedData != null) {
-      final byte[] adBytes = new byte[associatedData.remaining()];
-      associatedData.get(adBytes);
-
-      cipher.updateAAD(adBytes);
+      cipher.updateAAD(associatedData);
     }
 
     return finishDecryption(() -> cipher.doFinal(ciphertext, plaintext));
@@ -87,8 +79,6 @@ public int decrypt(final Key key,
   public int decrypt(final Key key,
                      final long nonce,
                      @Nullable final byte[] associatedData,
-                     final int aadOffset,
-                     final int aadLength,
                      final byte[] ciphertext,
                      final int ciphertextOffset,
                      final int ciphertextLength,
@@ -98,7 +88,7 @@ public int decrypt(final Key key,
     initCipher(cipher, Cipher.DECRYPT_MODE, key, nonce);
 
     if (associatedData != null) {
-      cipher.updateAAD(associatedData, aadOffset, aadLength);
+      cipher.updateAAD(associatedData);
     }
 
     return finishDecryption(() ->

diff --git a/src/main/java/com/eatthepath/noise/component/NoiseCipher.java b/src/main/java/com/eatthepath/noise/component/NoiseCipher.java
@@ -77,7 +77,7 @@ static NoiseCipher getInstance(final String noiseCipherName) throws NoSuchAlgori
    */
   default ByteBuffer encrypt(final Key key,
                              final long nonce,
-                             @Nullable final ByteBuffer associatedData,
+                             @Nullable final byte[] associatedData,
                              final ByteBuffer plaintext) {
 
     final ByteBuffer ciphertext = ByteBuffer.allocate(getCiphertextLength(plaintext.remaining()));
@@ -121,7 +121,7 @@ default ByteBuffer encrypt(final Key key,
    */
   int encrypt(final Key key,
               final long nonce,
-              @Nullable final ByteBuffer associatedData,
+              @Nullable final byte[] associatedData,
               final ByteBuffer plaintext,
               final ByteBuffer ciphertext)
       throws ShortBufferException;
@@ -150,8 +150,6 @@ default byte[] encrypt(final Key key,
       encrypt(key,
           nonce,
           associatedData,
-          0,
-          associatedData != null ? associatedData.length : 0,
           plaintext,
           0,
           plaintext.length,
@@ -175,10 +173,6 @@ default byte[] encrypt(final Key key,
    * @param nonce a nonce, which must be unique for the given key
    * @param associatedData a byte array containing the associated data (if any) to be used when encrypting the given
    *                       plaintext; may be {@code null}
-   * @param aadOffset the position within {@code associatedData} where the associated data starts; ignored if
-   *                  {@code associatedData} is {@code null}
-   * @param aadLength the length of the associated data within {@code associatedData}; ignored if {@code associatedData}
-   *                  is {@code null}
    * @param plaintext a byte array containing the plaintext to encrypt
    * @param plaintextOffset the offset within {@code plaintext} where the plaintext begins
    * @param plaintextLength the length of the plaintext within {@code plaintext}
@@ -198,8 +192,6 @@ default byte[] encrypt(final Key key,
   int encrypt(final Key key,
               final long nonce,
               @Nullable final byte[] associatedData,
-              final int aadOffset,
-              final int aadLength,
               final byte[] plaintext,
               final int plaintextOffset,
               final int plaintextLength,
@@ -229,7 +221,7 @@ int encrypt(final Key key,
    */
   default ByteBuffer decrypt(final Key key,
                              final long nonce,
-                             @Nullable final ByteBuffer associatedData,
+                             @Nullable final byte[] associatedData,
                              final ByteBuffer ciphertext) throws AEADBadTagException {
 
     final ByteBuffer plaintext = ByteBuffer.allocate(getPlaintextLength(ciphertext.remaining()));
@@ -272,7 +264,7 @@ default ByteBuffer decrypt(final Key key,
    */
   int decrypt(final Key key,
               final long nonce,
-              @Nullable final ByteBuffer associatedData,
+              @Nullable final byte[] associatedData,
               final ByteBuffer ciphertext,
               final ByteBuffer plaintext)
       throws AEADBadTagException, ShortBufferException;
@@ -304,8 +296,6 @@ default byte[] decrypt(final Key key,
       decrypt(key,
           nonce,
           associatedData,
-          0,
-          associatedData != null ? associatedData.length : 0,
           ciphertext,
           0,
           ciphertext.length,
@@ -330,10 +320,6 @@ default byte[] decrypt(final Key key,
    * @param nonce a nonce, which must be unique for the given key
    * @param associatedData a byte array containing the associated data (if any) to be used when verifying the AEAD tag
    *                       for the given ciphertext; may be {@code null}
-   * @param aadOffset the position within {@code associatedData} where the associated data starts; ignored if
-   *                  {@code associatedData} is {@code null}
-   * @param aadLength the length of the associated data within {@code associatedData}; ignored if {@code associatedData}
-   *                  is {@code null}
    * @param ciphertext a byte array containing the ciphertext and AEAD tag to be decrypted and verified
    * @param ciphertextOffset the position within {@code ciphertext} at which to begin reading the ciphertext and AEAD
    *                         tag
@@ -353,8 +339,6 @@ default byte[] decrypt(final Key key,
   int decrypt(final Key key,
               final long nonce,
               @Nullable final byte[] associatedData,
-              final int aadOffset,
-              final int aadLength,
               final byte[] ciphertext,
               final int ciphertextOffset,
               final int ciphertextLength,

diff --git a/src/test/java/com/eatthepath/noise/component/AbstractNoiseCipherTest.java b/src/test/java/com/eatthepath/noise/component/AbstractNoiseCipherTest.java
@@ -47,12 +47,12 @@ void encryptDecryptByteArrayInPlace() throws AEADBadTagException, ShortBufferExc
     System.arraycopy(plaintextBytes, 0, buffer, 0, plaintextBytes.length);
 
     assertEquals(buffer.length, getNoiseCipher().encrypt(key, nonce,
-        hash, 0, hash.length,
+        hash,
         buffer, 0, plaintextBytes.length,
         buffer, 0));
 
     assertEquals(plaintextBytes.length, getNoiseCipher().decrypt(key, nonce,
-        hash, 0, hash.length,
+        hash,
         buffer, 0, buffer.length,
         buffer, 0));
 
@@ -66,39 +66,26 @@ void encryptDecryptByteArrayInPlace() throws AEADBadTagException, ShortBufferExc
   void encryptDecryptNewByteBuffer() throws AEADBadTagException {
     final Key key = generateKey();
     final long nonce = ThreadLocalRandom.current().nextLong();
-
-    final ByteBuffer hashBuffer;
-    {
-      final byte[] hash = new byte[32];
-      ThreadLocalRandom.current().nextBytes(hash);
-
-      hashBuffer = ByteBuffer.wrap(hash);
-    }
+    final byte[] hash = new byte[32];
+    ThreadLocalRandom.current().nextBytes(hash);
 
     final ByteBuffer plaintext = ByteBuffer.wrap("Hark! Plaintext!".getBytes(StandardCharsets.UTF_8));
-    final ByteBuffer ciphertext = getNoiseCipher().encrypt(key, nonce, hashBuffer, plaintext);
+    final ByteBuffer ciphertext = getNoiseCipher().encrypt(key, nonce, hash, plaintext);
 
     plaintext.rewind();
-    hashBuffer.rewind();
 
     assertEquals(ciphertext.remaining(), getNoiseCipher().getCiphertextLength(plaintext.remaining()));
     assertEquals(plaintext.remaining(), getNoiseCipher().getPlaintextLength(ciphertext.remaining()));
 
-    assertEquals(plaintext, getNoiseCipher().decrypt(key, nonce, hashBuffer, ciphertext));
+    assertEquals(plaintext, getNoiseCipher().decrypt(key, nonce, hash, ciphertext));
   }
 
   @Test
   void encryptDecryptByteBufferInPlace() throws AEADBadTagException, ShortBufferException {
     final Key key = generateKey();
     final long nonce = ThreadLocalRandom.current().nextLong();
-
-    final ByteBuffer hashBuffer;
-    {
-      final byte[] hash = new byte[32];
-      ThreadLocalRandom.current().nextBytes(hash);
-
-      hashBuffer = ByteBuffer.wrap(hash);
-    }
+    final byte[] hash = new byte[32];
+    ThreadLocalRandom.current().nextBytes(hash);
 
     final byte[] plaintextBytes = "Hark! Plaintext!".getBytes(StandardCharsets.UTF_8);
     final byte[] sharedByteArray = new byte[getNoiseCipher().getCiphertextLength(plaintextBytes.length)];
@@ -111,18 +98,17 @@ void encryptDecryptByteBufferInPlace() throws AEADBadTagException, ShortBufferEx
     final ByteBuffer ciphertextBuffer = ByteBuffer.wrap(sharedByteArray);
 
     assertEquals(sharedByteArray.length,
-        getNoiseCipher().encrypt(key, nonce, hashBuffer, plaintextBuffer, ciphertextBuffer));
+        getNoiseCipher().encrypt(key, nonce, hash, plaintextBuffer, ciphertextBuffer));
 
     assertEquals(plaintextBytes.length, plaintextBuffer.limit());
     assertEquals(plaintextBuffer.limit(), plaintextBuffer.position());
     assertEquals(sharedByteArray.length, ciphertextBuffer.position());
 
-    hashBuffer.rewind();
     plaintextBuffer.rewind();
     ciphertextBuffer.rewind();
 
     assertEquals(plaintextBytes.length,
-        getNoiseCipher().decrypt(key, nonce, hashBuffer, ciphertextBuffer, plaintextBuffer));
+        getNoiseCipher().decrypt(key, nonce, hash, ciphertextBuffer, plaintextBuffer));
 
     assertEquals(plaintextBytes.length, plaintextBuffer.limit());
     assertEquals(plaintextBuffer.limit(), plaintextBuffer.position());