flyrain commented on code in PR #3231: URL: https://github.com/apache/iceberg/pull/3231#discussion_r902974131
########## core/src/main/java/org/apache/iceberg/encryption/AesGcmOutputStream.java: ########## @@ -0,0 +1,173 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ + +package org.apache.iceberg.encryption; + +import java.io.IOException; +import java.nio.ByteBuffer; +import java.nio.ByteOrder; +import java.nio.charset.StandardCharsets; +import java.security.GeneralSecurityException; +import java.security.InvalidAlgorithmParameterException; +import java.security.InvalidKeyException; +import java.security.SecureRandom; +import javax.crypto.Cipher; +import javax.crypto.SecretKey; +import javax.crypto.spec.GCMParameterSpec; +import javax.crypto.spec.SecretKeySpec; +import org.apache.iceberg.io.PositionOutputStream; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.apache.iceberg.relocated.com.google.common.primitives.Ints; + +public class AesGcmOutputStream extends PositionOutputStream { + // AES-GCM parameters + public static final int GCM_NONCE_LENGTH = 12; // in bytes + public static final int GCM_TAG_LENGTH = 16; // in bytes + public static final int GCM_TAG_LENGTH_BITS = 8 * GCM_TAG_LENGTH; + public static final String MAGIC_STRING = "GCM1"; + + static final byte[] MAGIC_ARRAY = MAGIC_STRING.getBytes(StandardCharsets.UTF_8); + static final int PREFIX_LENGTH = MAGIC_ARRAY.length + 4; // magic_len + block_size_len + + private PositionOutputStream targetStream; + + private Cipher gcmCipher; + private SecureRandom random; + private SecretKey key; + private byte[] nonce; + + private int blockSize = 1024 * 1024; + private byte[] plaintextBlockBuffer; + private int positionInBuffer; + private long streamPosition; + private int currentBlockIndex; + private byte[] fileAadPrefix; + + AesGcmOutputStream(PositionOutputStream targetStream, byte[] aesKey, byte[] fileAadPrefix) throws IOException { + this.targetStream = targetStream; + try { + gcmCipher = Cipher.getInstance("AES/GCM/NoPadding"); + } catch (GeneralSecurityException e) { + throw new IOException(e); + } + this.random = new SecureRandom(); + this.nonce = new byte[GCM_NONCE_LENGTH]; + this.key = new SecretKeySpec(aesKey, "AES"); + this.plaintextBlockBuffer = new byte[blockSize]; + this.positionInBuffer = 0; + this.streamPosition = 0; + this.currentBlockIndex = 0; + this.fileAadPrefix = fileAadPrefix; + + byte[] prefixBytes = ByteBuffer.allocate(PREFIX_LENGTH).order(ByteOrder.LITTLE_ENDIAN) + .put(MAGIC_ARRAY) + .putInt(blockSize) + .array(); + targetStream.write(prefixBytes); + } + + @Override + public void write(int b) throws IOException { + throw new UnsupportedOperationException(); + } + + @Override + public void write(byte[] b) throws IOException { + write(b, 0, b.length); + } + + @Override + public void write(byte[] b, int off, int len) throws IOException { + int remaining = len; + int offset = off; + + while (remaining > 0) { + int freeBlockBytes = blockSize - positionInBuffer; + int toWrite = freeBlockBytes <= remaining ? freeBlockBytes : remaining; + + System.arraycopy(b, offset, plaintextBlockBuffer, positionInBuffer, toWrite); + positionInBuffer += toWrite; + if (positionInBuffer == blockSize) { + encryptAndWriteBlock(); + positionInBuffer = 0; + } + offset += toWrite; + remaining -= toWrite; + } + + streamPosition += len; + } + + @Override + public long getPos() throws IOException { + return streamPosition; + } + + @Override + public void flush() throws IOException { + targetStream.flush(); + } + + @Override + public void close() throws IOException { + if (positionInBuffer > 0) { + encryptAndWriteBlock(); + } + targetStream.close(); + } + + private void encryptAndWriteBlock() throws IOException { + random.nextBytes(nonce); + GCMParameterSpec spec = new GCMParameterSpec(GCM_TAG_LENGTH_BITS, nonce); + try { + gcmCipher.init(Cipher.ENCRYPT_MODE, key, spec); + } catch (InvalidKeyException | InvalidAlgorithmParameterException e) { + throw new IOException("Failed to init GCM cipher", e); + } + + byte[] aad = calculateAAD(fileAadPrefix, currentBlockIndex); + gcmCipher.updateAAD(aad); + + byte[] cipherText = new byte[GCM_NONCE_LENGTH + positionInBuffer + GCM_TAG_LENGTH]; + System.arraycopy(nonce, 0, cipherText, 0, GCM_NONCE_LENGTH); + try { + int encrypted = gcmCipher.doFinal(plaintextBlockBuffer, 0, positionInBuffer, cipherText, GCM_NONCE_LENGTH); + Preconditions.checkArgument((encrypted == (positionInBuffer + GCM_TAG_LENGTH)), + "Wrong length of encrypted output: " + encrypted + " vs " + (positionInBuffer + GCM_TAG_LENGTH)); + } catch (GeneralSecurityException e) { + throw new IOException("Failed to encrypt", e); + } + + currentBlockIndex++; + + targetStream.write(cipherText); + } + + static byte[] calculateAAD(byte[] fileAadPrefix, int currentBlockIndex) { Review Comment: This can go to a common place as well since both classes need it. We may have a util class, e.g. `GcmUtil` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
