move size calculation methods to FileContentCryptor

src/main/java/org/cryptomator/cryptolib/api/Cryptor.java

@@ -10,8 +10,6 @@
 
 import javax.security.auth.Destroyable;
 
-import static com.google.common.base.Preconditions.checkArgument;
-
 public interface Cryptor extends Destroyable, AutoCloseable {
 
 	FileContentCryptor fileContentCryptor();
@@ -31,44 +29,4 @@ default void close() {
 		destroy();
 	}
 
-	/**
-	 * Calculates the size of the cleartext resulting from the given ciphertext decrypted with the given cryptor.
-	 *
-	 * @param ciphertextSize Length of encrypted payload. Not including the {@link FileHeaderCryptor#headerSize() length of the header}.
-	 * @return Cleartext length of a <code>ciphertextSize</code>-sized ciphertext decrypted with <code>cryptor</code>.
-	 */
-	default long cleartextSize(long ciphertextSize) {
-		checkArgument(ciphertextSize >= 0, "expected ciphertextSize to be positive, but was %s", ciphertextSize);
-		long cleartextChunkSize = fileContentCryptor().cleartextChunkSize();
-		long ciphertextChunkSize = fileContentCryptor().ciphertextChunkSize();
-		long overheadPerChunk = ciphertextChunkSize - cleartextChunkSize;
-		long numFullChunks = ciphertextSize / ciphertextChunkSize; // floor by int-truncation
-		long additionalCiphertextBytes = ciphertextSize % ciphertextChunkSize;
-		if (additionalCiphertextBytes > 0 && additionalCiphertextBytes <= overheadPerChunk) {
-			throw new IllegalArgumentException("Method not defined for input value " + ciphertextSize);
-		}
-		long additionalCleartextBytes = (additionalCiphertextBytes == 0) ? 0 : additionalCiphertextBytes - overheadPerChunk;
-		assert additionalCleartextBytes >= 0;
-		return cleartextChunkSize * numFullChunks + additionalCleartextBytes;
-	}
-
-	/**
-	 * Calculates the size of the ciphertext resulting from the given cleartext encrypted with the given cryptor.
-	 *
-	 * @param cleartextSize Length of a unencrypted payload.
-	 * @return Ciphertext length of a <code>cleartextSize</code>-sized cleartext encrypted with <code>cryptor</code>.
-	 * Not including the {@link FileHeader#getFilesize() length of the header}.
-	 */
-	default long ciphertextSize(long cleartextSize) {
-		checkArgument(cleartextSize >= 0, "expected cleartextSize to be positive, but was %s", cleartextSize);
-		long cleartextChunkSize = fileContentCryptor().cleartextChunkSize();
-		long ciphertextChunkSize = fileContentCryptor().ciphertextChunkSize();
-		long overheadPerChunk = ciphertextChunkSize - cleartextChunkSize;
-		long numFullChunks = cleartextSize / cleartextChunkSize; // floor by int-truncation
-		long additionalCleartextBytes = cleartextSize % cleartextChunkSize;
-		long additionalCiphertextBytes = (additionalCleartextBytes == 0) ? 0 : additionalCleartextBytes + overheadPerChunk;
-		assert additionalCiphertextBytes >= 0;
-		return ciphertextChunkSize * numFullChunks + additionalCiphertextBytes;
-	}
-
 }

src/main/java/org/cryptomator/cryptolib/api/FileContentCryptor.java

@@ -10,6 +10,8 @@
 
 import java.nio.ByteBuffer;
 
+import static com.google.common.base.Preconditions.checkArgument;
+
 public interface FileContentCryptor {
 
 	/**
@@ -73,4 +75,44 @@ public interface FileContentCryptor {
 	 */
 	void decryptChunk(ByteBuffer ciphertextChunk, ByteBuffer cleartextChunk, long chunkNumber, FileHeader header, boolean authenticate) throws AuthenticationFailedException;
 
+	/**
+	 * Calculates the size of the cleartext resulting from the given ciphertext decrypted with the given cryptor.
+	 *
+	 * @param ciphertextSize Length of encrypted payload. Not including the {@link FileHeaderCryptor#headerSize() length of the header}.
+	 * @return Cleartext length of a <code>ciphertextSize</code>-sized ciphertext decrypted with <code>cryptor</code>.
+	 */
+	default long cleartextSize(long ciphertextSize) {
+		checkArgument(ciphertextSize >= 0, "expected ciphertextSize to be positive, but was %s", ciphertextSize);
+		long cleartextChunkSize = cleartextChunkSize();
+		long ciphertextChunkSize = ciphertextChunkSize();
+		long overheadPerChunk = ciphertextChunkSize - cleartextChunkSize;
+		long numFullChunks = ciphertextSize / ciphertextChunkSize; // floor by int-truncation
+		long additionalCiphertextBytes = ciphertextSize % ciphertextChunkSize;
+		if (additionalCiphertextBytes > 0 && additionalCiphertextBytes <= overheadPerChunk) {
+			throw new IllegalArgumentException("Method not defined for input value " + ciphertextSize);
+		}
+		long additionalCleartextBytes = (additionalCiphertextBytes == 0) ? 0 : additionalCiphertextBytes - overheadPerChunk;
+		assert additionalCleartextBytes >= 0;
+		return cleartextChunkSize * numFullChunks + additionalCleartextBytes;
+	}
+
+	/**
+	 * Calculates the size of the ciphertext resulting from the given cleartext encrypted with the given cryptor.
+	 *
+	 * @param cleartextSize Length of a unencrypted payload.
+	 * @return Ciphertext length of a <code>cleartextSize</code>-sized cleartext encrypted with <code>cryptor</code>.
+	 * Not including the {@link FileHeader#getFilesize() length of the header}.
+	 */
+	default long ciphertextSize(long cleartextSize) {
+		checkArgument(cleartextSize >= 0, "expected cleartextSize to be positive, but was %s", cleartextSize);
+		long cleartextChunkSize = cleartextChunkSize();
+		long ciphertextChunkSize = ciphertextChunkSize();
+		long overheadPerChunk = ciphertextChunkSize - cleartextChunkSize;
+		long numFullChunks = cleartextSize / cleartextChunkSize; // floor by int-truncation
+		long additionalCleartextBytes = cleartextSize % cleartextChunkSize;
+		long additionalCiphertextBytes = (additionalCleartextBytes == 0) ? 0 : additionalCleartextBytes + overheadPerChunk;
+		assert additionalCiphertextBytes >= 0;
+		return ciphertextChunkSize * numFullChunks + additionalCiphertextBytes;
+	}
+
 }

src/main/java/org/cryptomator/cryptolib/api/FileHeader.java

@@ -11,7 +11,7 @@
 public interface FileHeader {
 
 	/**
-	 * @deprecated No longer supported since vault version 5. Use {@link org.cryptomator.cryptolib.api.Cryptor#cleartextSize(long)} to calculate the cleartext size from the ciphertext size
+	 * @deprecated No longer supported since vault version 5. Use {@link org.cryptomator.cryptolib.api.FileContentCryptor#cleartextSize(long)} to calculate the cleartext size from the ciphertext size
 	 * @return file size stored in file header
 	 */
 	@Deprecated

src/test/java/org/cryptomator/cryptolib/api/CryptorTest.java → src/test/java/org/cryptomator/cryptolib/api/FileContentCryptorTest.java

@@ -7,18 +7,16 @@
 import org.junit.jupiter.params.provider.ValueSource;
 import org.mockito.Mockito;
 
-public class CryptorTest {
+public class FileContentCryptorTest {
 
-	private final Cryptor cryptor = Mockito.mock(Cryptor.class);
+	private final FileContentCryptor contentCryptor = Mockito.mock(FileContentCryptor.class);
 
 	@BeforeEach
 	public void setup() {
-		FileContentCryptor contentCryptor = Mockito.mock(FileContentCryptor.class);
-		Mockito.when(cryptor.fileContentCryptor()).thenReturn(contentCryptor);
 		Mockito.when(contentCryptor.cleartextChunkSize()).thenReturn(32);
 		Mockito.when(contentCryptor.ciphertextChunkSize()).thenReturn(40);
-		Mockito.doCallRealMethod().when(cryptor).cleartextSize(Mockito.anyLong());
-		Mockito.doCallRealMethod().when(cryptor).ciphertextSize(Mockito.anyLong());
+		Mockito.doCallRealMethod().when(contentCryptor).cleartextSize(Mockito.anyLong());
+		Mockito.doCallRealMethod().when(contentCryptor).ciphertextSize(Mockito.anyLong());
 	}
 
 	@ParameterizedTest(name = "cleartextSize({1}) == {0}")
@@ -34,14 +32,14 @@ public void setup() {
 			"65,89"
 	})
 	public void testCleartextSize(int cleartextSize, int ciphertextSize) {
-		Assertions.assertEquals(cleartextSize, cryptor.cleartextSize(ciphertextSize));
+		Assertions.assertEquals(cleartextSize, contentCryptor.cleartextSize(ciphertextSize));
 	}
 
 	@ParameterizedTest(name = "cleartextSize({0}) == undefined")
 	@ValueSource(ints = {-1, 1, 8, 41, 48, 81, 88})
 	public void testCleartextSizeWithInvalidCiphertextSize(int invalidCiphertextSize) {
 		Assertions.assertThrows(IllegalArgumentException.class, () -> {
-			cryptor.cleartextSize(invalidCiphertextSize);
+			contentCryptor.cleartextSize(invalidCiphertextSize);
 		});
 	}
 
@@ -58,14 +56,14 @@ public void testCleartextSizeWithInvalidCiphertextSize(int invalidCiphertextSize
 			"65,89"
 	})
 	public void testCiphertextSize(int cleartextSize, int ciphertextSize) {
-		Assertions.assertEquals(ciphertextSize, cryptor.ciphertextSize(cleartextSize));
+		Assertions.assertEquals(ciphertextSize, contentCryptor.ciphertextSize(cleartextSize));
 	}
 
 	@ParameterizedTest(name = "ciphertextSize({0}) == undefined")
 	@ValueSource(ints = {-1})
 	public void testCiphertextSizewithInvalidCleartextSize(int invalidCleartextSize) {
 		Assertions.assertThrows(IllegalArgumentException.class, () -> {
-			cryptor.ciphertextSize(invalidCleartextSize);
+			contentCryptor.ciphertextSize(invalidCleartextSize);
 		});
 	}