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/*
 * Copyright 2013-2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *  http://aws.amazon.com/apache2.0
 *
 * or in the "license" file accompanying this file. This file 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 com.amazonaws.services.s3.internal.crypto;

import static com.amazonaws.services.s3.AmazonS3EncryptionClient.USER_AGENT;
import static com.amazonaws.services.s3.model.CryptoStorageMode.InstructionFile;
import static com.amazonaws.services.s3.model.CryptoStorageMode.ObjectMetadata;
import static com.amazonaws.services.s3.model.InstructionFileId.DEFAULT_INSTRUCTION_FILE_SUFFIX;
import static com.amazonaws.services.s3.model.InstructionFileId.DOT;
import static com.amazonaws.services.s3.model.S3DataSource.Utils.cleanupDataSource;
import static com.amazonaws.util.BinaryUtils.copyAllBytesFrom;
import static com.amazonaws.util.IOUtils.closeQuietly;
import static com.amazonaws.util.LengthCheckInputStream.EXCLUDE_SKIPPED_BYTES;
import static com.amazonaws.util.StringUtils.UTF8;

import com.amazonaws.AmazonClientException;
import com.amazonaws.AmazonServiceException;
import com.amazonaws.AmazonWebServiceRequest;
import com.amazonaws.auth.AWSCredentialsProvider;
import com.amazonaws.internal.ReleasableInputStream;
import com.amazonaws.internal.ResettableInputStream;
import com.amazonaws.internal.SdkFilterInputStream;
import com.amazonaws.services.kms.AWSKMSClient;
import com.amazonaws.services.kms.model.GenerateDataKeyRequest;
import com.amazonaws.services.kms.model.GenerateDataKeyResult;
import com.amazonaws.services.s3.Headers;
import com.amazonaws.services.s3.internal.InputSubstream;
import com.amazonaws.services.s3.internal.S3Direct;
import com.amazonaws.services.s3.model.AbortMultipartUploadRequest;
import com.amazonaws.services.s3.model.AbstractPutObjectRequest;
import com.amazonaws.services.s3.model.CompleteMultipartUploadRequest;
import com.amazonaws.services.s3.model.CompleteMultipartUploadResult;
import com.amazonaws.services.s3.model.CopyPartRequest;
import com.amazonaws.services.s3.model.CopyPartResult;
import com.amazonaws.services.s3.model.CryptoConfiguration;
import com.amazonaws.services.s3.model.CryptoMode;
import com.amazonaws.services.s3.model.EncryptionMaterials;
import com.amazonaws.services.s3.model.EncryptionMaterialsFactory;
import com.amazonaws.services.s3.model.EncryptionMaterialsProvider;
import com.amazonaws.services.s3.model.GetObjectRequest;
import com.amazonaws.services.s3.model.InitiateMultipartUploadRequest;
import com.amazonaws.services.s3.model.InitiateMultipartUploadResult;
import com.amazonaws.services.s3.model.InstructionFileId;
import com.amazonaws.services.s3.model.MaterialsDescriptionProvider;
import com.amazonaws.services.s3.model.ObjectMetadata;
import com.amazonaws.services.s3.model.PutInstructionFileRequest;
import com.amazonaws.services.s3.model.PutObjectRequest;
import com.amazonaws.services.s3.model.PutObjectResult;
import com.amazonaws.services.s3.model.S3Object;
import com.amazonaws.services.s3.model.S3ObjectId;
import com.amazonaws.services.s3.model.UploadObjectRequest;
import com.amazonaws.services.s3.model.UploadPartRequest;
import com.amazonaws.services.s3.model.UploadPartResult;
import com.amazonaws.services.s3.util.Mimetypes;
import com.amazonaws.util.IOUtils;
import com.amazonaws.util.LengthCheckInputStream;
import com.amazonaws.util.json.JsonUtils;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.KeyPair;
import java.security.NoSuchAlgorithmException;
import java.security.Provider;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

/**
 * Common implementation for different S3 cryptographic modules.
 * @param  class type.
 */
public abstract class S3CryptoModuleBase
        extends S3CryptoModule {
    private static final boolean IS_MULTI_PART = true;
    protected static final int DEFAULT_BUFFER_SIZE = 1024 * 2;    // 2K
    private static final int MAX_RETRY_COUNT = 9;
    protected final EncryptionMaterialsProvider kekMaterialsProvider;
    protected final Log log = LogFactory.getLog(getClass());
    protected final S3CryptoScheme cryptoScheme;
    protected final ContentCryptoScheme contentCryptoScheme;
    /** A read-only copy of the crypto configuration. */
    protected final CryptoConfiguration cryptoConfig;

    /** Map of data about in progress encrypted multipart uploads. */
    protected final  Map multipartUploadContexts =
            Collections.synchronizedMap(new HashMap());
    protected final S3Direct s3;
    protected final AWSKMSClient kms;

    /**
     * @param cryptoConfig a read-only copy of the crypto configuration.
     */
    protected S3CryptoModuleBase(AWSKMSClient kms, S3Direct s3,
            AWSCredentialsProvider credentialsProvider,
            EncryptionMaterialsProvider kekMaterialsProvider,
            CryptoConfiguration cryptoConfig) {
        if (!cryptoConfig.isReadOnly()) {
            throw new IllegalArgumentException("The cryto configuration parameter is required to be read-only");
        }
        this.kekMaterialsProvider = kekMaterialsProvider;
        this.s3 = s3;
        this.cryptoConfig = cryptoConfig;
        this.cryptoScheme = S3CryptoScheme.from(cryptoConfig.getCryptoMode());
        this.contentCryptoScheme = cryptoScheme.getContentCryptoScheme();
        this.kms = kms;
    }

    /**
     * For testing purposes only.
     */
    protected S3CryptoModuleBase(S3Direct s3,
            AWSCredentialsProvider credentialsProvider,
            EncryptionMaterialsProvider kekMaterialsProvider,
            CryptoConfiguration cryptoConfig) {
        this.kekMaterialsProvider = kekMaterialsProvider;
        this.s3 = s3;
        this.cryptoConfig = cryptoConfig;
        this.cryptoScheme = S3CryptoScheme.from(cryptoConfig.getCryptoMode());
        this.contentCryptoScheme = cryptoScheme.getContentCryptoScheme();
        this.kms = null;
    }

    /**
     * Returns the length of the ciphertext computed from the length of the
     * plaintext.
     *
     * @param plaintextLength
     *            a non-negative number
     * @return a non-negative number
     */
    protected abstract long ciphertextLength(long plaintextLength);

    //////////////////////// Common Implementation ////////////////////////
    @Override
    public PutObjectResult putObjectSecurely(PutObjectRequest req) {
        // TODO: consider cloning req before proceeding further to reduce side
        // effects
        appendUserAgent(req, USER_AGENT);
        return cryptoConfig.getStorageMode() == InstructionFile
             ? putObjectUsingInstructionFile(req)
             : putObjectUsingMetadata(req);
    }

    private PutObjectResult putObjectUsingMetadata(PutObjectRequest req) {
        final ContentCryptoMaterial cekMaterial = createContentCryptoMaterial(req);
        // Wraps the object data with a cipher input stream
        final File fileOrig = req.getFile();
        final InputStream isOrig = req.getInputStream();
        final PutObjectRequest wrappedReq = wrapWithCipher(req, cekMaterial);
        // Update the metadata
        req.setMetadata(updateMetadataWithContentCryptoMaterial(
                req.getMetadata(), req.getFile(), cekMaterial));
        // Put the encrypted object into S3
        try {
            return s3.putObject(wrappedReq);
        } finally {
            cleanupDataSource(req, fileOrig, isOrig, wrappedReq.getInputStream(), log);
        }
    }

    /**
     * Puts an encrypted object into S3, and puts an instruction file into S3.
     * Encryption info is stored in the instruction file.
     *
     * @param putObjectRequest
     *            The request object containing all the parameters to upload a
     *            new object to Amazon S3.
     * @return A {@link PutObjectResult} object containing the information
     *         returned by Amazon S3 for the new, created object.
     */
    private PutObjectResult putObjectUsingInstructionFile(
            PutObjectRequest putObjectRequest) {
        final File fileOrig = putObjectRequest.getFile();
        final InputStream isOrig = putObjectRequest.getInputStream();
        final PutObjectRequest putInstFileRequest = putObjectRequest.clone()
            .withFile(null)
            .withInputStream(null);
        putInstFileRequest.setKey(putInstFileRequest.getKey() + DOT
                + DEFAULT_INSTRUCTION_FILE_SUFFIX);
        // Create instruction
        final ContentCryptoMaterial cekMaterial = createContentCryptoMaterial(putObjectRequest);
        // Wraps the object data with a cipher input stream; note the metadata
        // is mutated as a side effect.
        final PutObjectRequest req = wrapWithCipher(putObjectRequest, cekMaterial);
        // Put the encrypted object into S3
        final PutObjectResult result;
        try {
            result = s3.putObject(req);
        } finally {
            cleanupDataSource(putObjectRequest, fileOrig, isOrig,
                    req.getInputStream(), log);
        }
        // Put the instruction file into S3
        s3.putObject(updateInstructionPutRequest(putInstFileRequest,
                cekMaterial));
        // Return the result of the encrypted object PUT.
        return result;
    }

    @Override
    public final void abortMultipartUploadSecurely(AbortMultipartUploadRequest req) {
        s3.abortMultipartUpload(req);
        multipartUploadContexts.remove(req.getUploadId());
    }

    @Override
    public final CopyPartResult copyPartSecurely(CopyPartRequest copyPartRequest) {
        final String uploadId = copyPartRequest.getUploadId();
        final T uploadContext = multipartUploadContexts.get(uploadId);
        final CopyPartResult result = s3.copyPart(copyPartRequest);

        if (uploadContext != null && !uploadContext.hasFinalPartBeenSeen()) {
            uploadContext.setHasFinalPartBeenSeen(true);
        }
        return result;
    }

    abstract T newUploadContext(InitiateMultipartUploadRequest req,
            ContentCryptoMaterial cekMaterial);

    @Override
    public InitiateMultipartUploadResult initiateMultipartUploadSecurely(
            InitiateMultipartUploadRequest req) {
        appendUserAgent(req, USER_AGENT);
        // Generate a one-time use symmetric key and initialize a cipher to
        // encrypt object data
        final ContentCryptoMaterial cekMaterial = createContentCryptoMaterial(req);
        if (cryptoConfig.getStorageMode() == ObjectMetadata) {
            ObjectMetadata metadata = req.getObjectMetadata();
            if (metadata == null) {
                metadata = new ObjectMetadata();
            }
            // Store encryption info in metadata
            req.setObjectMetadata(updateMetadataWithContentCryptoMaterial(
                    metadata, null, cekMaterial));
        }
        final InitiateMultipartUploadResult result = s3.initiateMultipartUpload(req);
        final T uploadContext = newUploadContext(req, cekMaterial);
        if (req instanceof MaterialsDescriptionProvider) {
            final MaterialsDescriptionProvider p = (MaterialsDescriptionProvider) req;
            uploadContext.setMaterialsDescription(p.getMaterialsDescription());
        }
        multipartUploadContexts.put(result.getUploadId(), uploadContext);
        return result;
    }

    //// specific crypto module behavior for uploading parts.
    abstract CipherLite cipherLiteForNextPart(T uploadContext);
    abstract long computeLastPartSize(UploadPartRequest req);
    abstract  SdkFilterInputStream wrapForMultipart(
            I is, long partSize);
    abstract void updateUploadContext(T uploadContext, SdkFilterInputStream is);
    /**
     * {@inheritDoc}
     *
     * 

* NOTE: Because the encryption process requires context from * previous blocks, parts uploaded with the AmazonS3EncryptionClient (as * opposed to the normal AmazonS3Client) must be uploaded serially, and in * order. Otherwise, the previous encryption context isn't available to use * when encrypting the current part. */ @Override public UploadPartResult uploadPartSecurely(UploadPartRequest req) { appendUserAgent(req, USER_AGENT); final int blockSize = contentCryptoScheme.getBlockSizeInBytes(); final boolean isLastPart = req.isLastPart(); final String uploadId = req.getUploadId(); final long partSize = req.getPartSize(); final boolean partSizeMultipleOfCipherBlockSize = 0 == (partSize % blockSize); if (!isLastPart && !partSizeMultipleOfCipherBlockSize) { throw new AmazonClientException( "Invalid part size: part sizes for encrypted multipart uploads must be multiples " + "of the cipher block size (" + blockSize + ") with the exception of the last part."); } final T uploadContext = multipartUploadContexts.get(uploadId); if (uploadContext == null) { throw new AmazonClientException( "No client-side information available on upload ID " + uploadId); } final UploadPartResult result; // Checks the parts are uploaded in series uploadContext.beginPartUpload(req.getPartNumber()); final CipherLite cipherLite = cipherLiteForNextPart(uploadContext); final File fileOrig = req.getFile(); final InputStream isOrig = req.getInputStream(); SdkFilterInputStream isCurr = null; try { final CipherLiteInputStream clis = newMultipartS3CipherInputStream(req, cipherLite); isCurr = clis; // so the clis will be closed (in the finally block below) upon // unexpected failure should we opened a file undereath isCurr = wrapForMultipart(clis, partSize); req.setInputStream(isCurr); // Treat all encryption requests as input stream upload requests, // not as file upload requests. req.setFile(null); req.setFileOffset(0); // The last part of the multipart upload will contain an extra // 16-byte mac if (isLastPart) { // We only change the size of the last part final long lastPartSize = computeLastPartSize(req); if (lastPartSize > -1) { req.setPartSize(lastPartSize); } if (uploadContext.hasFinalPartBeenSeen()) { throw new AmazonClientException( "This part was specified as the last part in a multipart upload, but a previous part was already marked as the last part. " + "Only the last part of the upload should be marked as the last part."); } } result = s3.uploadPart(req); } finally { cleanupDataSource(req, fileOrig, isOrig, isCurr, log); uploadContext.endPartUpload(); } if (isLastPart) { uploadContext.setHasFinalPartBeenSeen(true); } updateUploadContext(uploadContext, isCurr); return result; } protected final CipherLiteInputStream newMultipartS3CipherInputStream( UploadPartRequest req, CipherLite cipherLite) { final File fileOrig = req.getFile(); final InputStream isOrig = req.getInputStream(); InputStream isCurr = null; try { if (fileOrig == null) { if (isOrig == null) { throw new IllegalArgumentException( "A File or InputStream must be specified when uploading part"); } isCurr = isOrig; } else { isCurr = new ResettableInputStream(fileOrig); } isCurr = new InputSubstream(isCurr, req.getFileOffset(), req.getPartSize(), req.isLastPart()); return cipherLite.markSupported() ? new CipherLiteInputStream(isCurr, cipherLite, DEFAULT_BUFFER_SIZE, IS_MULTI_PART, req.isLastPart()) : new RenewableCipherLiteInputStream(isCurr, cipherLite, DEFAULT_BUFFER_SIZE, IS_MULTI_PART, req.isLastPart()); } catch (final Exception e) { cleanupDataSource(req, fileOrig, isOrig, isCurr, log); throw new AmazonClientException("Unable to create cipher input stream", e); } } @Override public CompleteMultipartUploadResult completeMultipartUploadSecurely( CompleteMultipartUploadRequest req) { appendUserAgent(req, USER_AGENT); final String uploadId = req.getUploadId(); final T uploadContext = multipartUploadContexts.get(uploadId); if (uploadContext != null && !uploadContext.hasFinalPartBeenSeen()) { throw new AmazonClientException( "Unable to complete an encrypted multipart upload without being told which part was the last. " + "Without knowing which part was the last, the encrypted data in Amazon S3 is incomplete and corrupt."); } final CompleteMultipartUploadResult result = s3.completeMultipartUpload(req); // In InstructionFile mode, we want to write the instruction file only // after the whole upload has completed correctly. if (uploadContext != null && cryptoConfig.getStorageMode() == InstructionFile) { // Put the instruction file into S3 s3.putObject(createInstructionPutRequest( uploadContext.getBucketName(), uploadContext.getKey(), uploadContext.getContentCryptoMaterial())); } multipartUploadContexts.remove(uploadId); return result; } protected final ObjectMetadata updateMetadataWithContentCryptoMaterial( ObjectMetadata metadata, File file, ContentCryptoMaterial instruction) { if (metadata == null) { metadata = new ObjectMetadata(); } if (file != null) { final Mimetypes mimetypes = Mimetypes.getInstance(); metadata.setContentType(mimetypes.getMimetype(file)); } return instruction.toObjectMetadata(metadata, cryptoConfig.getCryptoMode()); } /** * Creates and returns a non-null content crypto material for the given * request. * * @throws AmazonClientException if no encryption material can be found. */ protected final ContentCryptoMaterial createContentCryptoMaterial( AmazonWebServiceRequest req) { if (req instanceof EncryptionMaterialsFactory) { // per request level encryption materials final EncryptionMaterialsFactory f = (EncryptionMaterialsFactory) req; final EncryptionMaterials materials = f.getEncryptionMaterials(); if (materials != null) { return buildContentCryptoMaterial(materials, cryptoConfig.getCryptoProvider(), req); } } if (req instanceof MaterialsDescriptionProvider) { // per request level material description final MaterialsDescriptionProvider mdp = (MaterialsDescriptionProvider) req; final Map matdescReq = mdp.getMaterialsDescription(); final ContentCryptoMaterial ccm = newContentCryptoMaterial( kekMaterialsProvider, matdescReq, cryptoConfig.getCryptoProvider(), req); if (ccm != null) { return ccm; } if (matdescReq != null) { // check to see if KMS is in use and if so we should fall thru // to the s3 client level encryption material final EncryptionMaterials material = kekMaterialsProvider.getEncryptionMaterials(); if (!material.isKMSEnabled()) { throw new AmazonClientException( "No material available from the encryption material provider for description " + matdescReq); } } // if there is no material description, fall thru to use // the per s3 client level encryption materials } // per s3 client level encryption materials return newContentCryptoMaterial(this.kekMaterialsProvider, cryptoConfig.getCryptoProvider(), req); } /** * Returns the content encryption material generated with the given kek * material, material description and security providers; or null if * the encryption material cannot be found for the specified description. */ private ContentCryptoMaterial newContentCryptoMaterial( EncryptionMaterialsProvider kekMaterialProvider, Map materialsDescription, Provider provider, AmazonWebServiceRequest req) { final EncryptionMaterials kekMaterials = kekMaterialProvider.getEncryptionMaterials(materialsDescription); if (kekMaterials == null) { return null; } return buildContentCryptoMaterial(kekMaterials, provider, req); } /** * Returns a non-null content encryption material generated with the given * kek material and security providers. * * @throws AmazonClientException if no encryption material can be found from * the given encryption material provider. */ private ContentCryptoMaterial newContentCryptoMaterial( EncryptionMaterialsProvider kekMaterialProvider, Provider provider, AmazonWebServiceRequest req) { final EncryptionMaterials kekMaterials = kekMaterialProvider.getEncryptionMaterials(); if (kekMaterials == null) { throw new AmazonClientException("No material available from the encryption material provider"); } return buildContentCryptoMaterial(kekMaterials, provider, req); } @Override public final void putLocalObjectSecurely(final UploadObjectRequest reqIn, String uploadId, OutputStream os) throws IOException { UploadObjectRequest req = reqIn.clone(); final File fileOrig = req.getFile(); final InputStream isOrig = req.getInputStream(); final T uploadContext = multipartUploadContexts.get(uploadId); final ContentCryptoMaterial cekMaterial = uploadContext.getContentCryptoMaterial(); req = wrapWithCipher(req, cekMaterial); try { IOUtils.copy(req.getInputStream(), os); // so it won't crap out with a false negative at the end; (Not // really relevant here) uploadContext.setHasFinalPartBeenSeen(true); } finally { cleanupDataSource(req, fileOrig, isOrig, req.getInputStream(), log); IOUtils.closeQuietly(os, log); } return; } /** * @param materials a non-null encryption material */ private ContentCryptoMaterial buildContentCryptoMaterial( EncryptionMaterials materials, Provider provider, AmazonWebServiceRequest req) { // Randomly generate the IV final byte[] iv = new byte[contentCryptoScheme.getIVLengthInBytes()]; cryptoScheme.getSecureRandom().nextBytes(iv); if (materials.isKMSEnabled()) { final Map encryptionContext = ContentCryptoMaterial.mergeMaterialDescriptions(materials, req); final GenerateDataKeyRequest keyGenReq = new GenerateDataKeyRequest() .withEncryptionContext(encryptionContext) .withKeyId(materials.getCustomerMasterKeyId()) .withKeySpec(contentCryptoScheme.getKeySpec()); keyGenReq .withGeneralProgressListener(req.getGeneralProgressListener()) .withRequestMetricCollector(req.getRequestMetricCollector()); final GenerateDataKeyResult keyGenRes = kms.generateDataKey(keyGenReq); final SecretKey cek = new SecretKeySpec(copyAllBytesFrom(keyGenRes.getPlaintext()), contentCryptoScheme.getKeyGeneratorAlgorithm()); final byte[] keyBlob = copyAllBytesFrom(keyGenRes.getCiphertextBlob()); return ContentCryptoMaterial.wrap(cek, iv, contentCryptoScheme, provider, new KMSSecuredCEK(keyBlob, encryptionContext)); } else { // Generate a one-time use symmetric key and initialize a cipher to encrypt object data return ContentCryptoMaterial.create( generateCEK(materials, provider), iv, materials, cryptoScheme, provider, kms, req); } } /** * @param kekMaterials non-null encryption materials */ protected final SecretKey generateCEK( final EncryptionMaterials kekMaterials, final Provider providerIn) { final String keygenAlgo = contentCryptoScheme.getKeyGeneratorAlgorithm(); KeyGenerator generator; try { generator = providerIn == null ? KeyGenerator.getInstance(keygenAlgo) : KeyGenerator.getInstance(keygenAlgo, providerIn); generator.init(contentCryptoScheme.getKeyLengthInBits(), cryptoScheme.getSecureRandom()); // Set to true iff the key encryption involves the use of BC's public key boolean involvesBCPublicKey = false; final KeyPair keypair = kekMaterials.getKeyPair(); if (keypair != null) { final String keyWrapAlgo = cryptoScheme.getKeyWrapScheme().getKeyWrapAlgorithm(keypair.getPublic()); if (keyWrapAlgo == null) { final Provider provider = generator.getProvider(); final String providerName = provider == null ? null : provider.getName(); involvesBCPublicKey = CryptoRuntime.BOUNCY_CASTLE_PROVIDER.equals(providerName); } } SecretKey secretKey = generator.generateKey(); if (!involvesBCPublicKey || secretKey.getEncoded()[0] != 0) { return secretKey; } for (int retry = 0; retry < MAX_RETRY_COUNT; retry++) { // Regenerate the random key due to a bug/feature in BC: // https://github.com/aws/aws-sdk-android/issues/15 secretKey = generator.generateKey(); if (secretKey.getEncoded()[0] != 0) { return secretKey; } } // The probability of getting here is 2^80, which is impossible in practice. throw new AmazonClientException("Failed to generate secret key"); } catch (final NoSuchAlgorithmException e) { throw new AmazonClientException( "Unable to generate envelope symmetric key:" + e.getMessage(), e); } } /** * Returns the given PutObjectRequest but has the content as * input stream wrapped with a cipher, and configured with some meta data * and user metadata. */ protected final R wrapWithCipher( final R request, ContentCryptoMaterial cekMaterial) { // Create a new metadata object if there is no metadata already. ObjectMetadata metadata = request.getMetadata(); if (metadata == null) { metadata = new ObjectMetadata(); } // Record the original Content MD5, if present, for the unencrypted data if (metadata.getContentMD5() != null) { metadata.addUserMetadata(Headers.UNENCRYPTED_CONTENT_MD5, metadata.getContentMD5()); } // Removes the original content MD5 if present from the meta data. metadata.setContentMD5(null); // Record the original, unencrypted content-length so it can be accessed // later final long plaintextLength = plaintextLength(request, metadata); if (plaintextLength >= 0) { metadata.addUserMetadata(Headers.UNENCRYPTED_CONTENT_LENGTH, Long.toString(plaintextLength)); // Put the ciphertext length in the metadata metadata.setContentLength(ciphertextLength(plaintextLength)); } request.setMetadata(metadata); request.setInputStream(newS3CipherLiteInputStream( request, cekMaterial, plaintextLength)); // Treat all encryption requests as input stream upload requests, not as // file upload requests. request.setFile(null); return request; } private CipherLiteInputStream newS3CipherLiteInputStream( AbstractPutObjectRequest req, ContentCryptoMaterial cekMaterial, long plaintextLength) { final File fileOrig = req.getFile(); final InputStream isOrig = req.getInputStream(); InputStream isCurr = null; try { if (fileOrig == null) { // When input is a FileInputStream, this wrapping enables // unlimited mark-and-reset isCurr = isOrig == null ? null : ReleasableInputStream.wrap(isOrig); } else { isCurr = new ResettableInputStream(fileOrig); } if (plaintextLength > -1) { // S3 allows a single PUT to be no more than 5GB, which // therefore won't exceed the maximum length that can be // encrypted either using any cipher such as CBC or GCM. // This ensures the plain-text read from the underlying data // stream has the same length as the expected total. isCurr = new LengthCheckInputStream(isCurr, plaintextLength, EXCLUDE_SKIPPED_BYTES); } final CipherLite cipherLite = cekMaterial.getCipherLite(); if (cipherLite.markSupported()) { return new CipherLiteInputStream(isCurr, cipherLite, DEFAULT_BUFFER_SIZE); } else { return new RenewableCipherLiteInputStream(isCurr, cipherLite, DEFAULT_BUFFER_SIZE); } } catch (final Exception e) { cleanupDataSource(req, fileOrig, isOrig, isCurr, log); throw new AmazonClientException("Unable to create cipher input stream", e); } } /** * Returns the plaintext length from the request and metadata; or -1 if * unknown. */ protected final long plaintextLength(AbstractPutObjectRequest request, ObjectMetadata metadata) { if (request.getFile() != null) { return request.getFile().length(); } else if (request.getInputStream() != null && metadata.getRawMetadataValue(Headers.CONTENT_LENGTH) != null) { return metadata.getContentLength(); } return -1; } public final S3CryptoScheme getS3CryptoScheme() { return cryptoScheme; } /** * Updates put request to store the specified instruction object in S3. * * @param req * The put-instruction-file request for the instruction file to * be stored in S3. * @param cekMaterial * The instruction object to be stored in S3. * @return A put request to store the specified instruction object in S3. */ protected final PutObjectRequest updateInstructionPutRequest( PutObjectRequest req, ContentCryptoMaterial cekMaterial) { final byte[] bytes = cekMaterial.toJsonString(cryptoConfig.getCryptoMode()) .getBytes(UTF8); ObjectMetadata metadata = req.getMetadata(); if (metadata == null) { metadata = new ObjectMetadata(); req.setMetadata(metadata); } // Set the content-length of the upload metadata.setContentLength(bytes.length); // Set the crypto instruction file header metadata.addUserMetadata(Headers.CRYPTO_INSTRUCTION_FILE, ""); // Update the instruction request req.setMetadata(metadata); req.setInputStream(new ByteArrayInputStream(bytes)); // the file attribute in the request is always null before calling this // routine return req; } protected final PutObjectRequest createInstructionPutRequest( String bucketName, String key, ContentCryptoMaterial cekMaterial) { final byte[] bytes = cekMaterial.toJsonString(cryptoConfig.getCryptoMode()) .getBytes(UTF8); final InputStream is = new ByteArrayInputStream(bytes); final ObjectMetadata metadata = new ObjectMetadata(); metadata.setContentLength(bytes.length); metadata.addUserMetadata(Headers.CRYPTO_INSTRUCTION_FILE, ""); final InstructionFileId ifileId = new S3ObjectId(bucketName, key) .instructionFileId(); return new PutObjectRequest(ifileId.getBucket(), ifileId.getKey(), is, metadata); } /** * Appends a user agent to the request's USER_AGENT client marker. * This method is intended only for internal use by the AWS SDK. */ final X appendUserAgent( X request, String userAgent) { request.getRequestClientOptions().appendUserAgent(userAgent); return request; } /** * Checks if the the crypto scheme used in the given content crypto material * is allowed to be used in this crypto module. Default is no-op. Subclass * may override. * * @throws SecurityException * if the crypto scheme used in the given content crypto * material is not allowed in this crypto module. */ protected void securityCheck(ContentCryptoMaterial cekMaterial, S3ObjectWrapper retrieved) { } /** * Retrieves an instruction file from S3; or null if no instruction file is * found. * * @param s3ObjectId * the S3 object id (not the instruction file id) * @param instFileSuffix * suffix of the instruction file to be retrieved; or null to use * the default suffix. * @return an instruction file, or null if no instruction file is found. */ final S3ObjectWrapper fetchInstructionFile(S3ObjectId s3ObjectId, String instFileSuffix) { try { final S3Object o = s3.getObject( createInstructionGetRequest(s3ObjectId, instFileSuffix)); return o == null ? null : new S3ObjectWrapper(o, s3ObjectId); } catch (final AmazonServiceException e) { // If no instruction file is found, log a debug message, and return // null. if (log.isDebugEnabled()) { log.debug("Unable to retrieve instruction file : " + e.getMessage()); } return null; } } @Override public final PutObjectResult putInstructionFileSecurely( PutInstructionFileRequest req) { final S3ObjectId id = req.getS3ObjectId(); final GetObjectRequest getreq = new GetObjectRequest(id); appendUserAgent(getreq, USER_AGENT); // Get the object from S3 final S3Object retrieved = s3.getObject(getreq); // We only need the meta-data already retrieved, not the data stream. // So close it immediately to prevent resource leakage. closeQuietly(retrieved, log); if (retrieved == null) { throw new IllegalArgumentException( "The specified S3 object (" + id + ") doesn't exist."); } final S3ObjectWrapper wrapped = new S3ObjectWrapper(retrieved, id); try { final ContentCryptoMaterial origCCM = contentCryptoMaterialOf(wrapped); if (ContentCryptoScheme.AES_GCM.equals(origCCM.getContentCryptoScheme()) && cryptoConfig.getCryptoMode() == CryptoMode.EncryptionOnly) { throw new SecurityException( "Lowering the protection of encryption material is not allowed"); } securityCheck(origCCM, wrapped); // Re-ecnrypt the CEK in a new content crypto material final EncryptionMaterials newKEK = req.getEncryptionMaterials(); final ContentCryptoMaterial newCCM; if (newKEK == null) { newCCM = origCCM.recreate(req.getMaterialsDescription(), this.kekMaterialsProvider, cryptoScheme, cryptoConfig.getCryptoProvider(), kms, req); } else { newCCM = origCCM.recreate(newKEK, this.kekMaterialsProvider, cryptoScheme, cryptoConfig.getCryptoProvider(), kms, req); } final PutObjectRequest putInstFileRequest = req.createPutObjectRequest(retrieved); // Put the new instruction file into S3 return s3.putObject(updateInstructionPutRequest(putInstFileRequest, newCCM)); } catch (final RuntimeException ex) { // If we're unable to set up the decryption, make sure we close the // HTTP connection closeQuietly(retrieved, log); throw ex; } catch (final Error error) { closeQuietly(retrieved, log); throw error; } } /** * Returns the content crypto material of an existing S3 object. * * @param s3w * an existing S3 object (wrapper) * @param s3objectId * the object id used to retrieve the existing S3 object * * @return a non-null content crypto material. */ private ContentCryptoMaterial contentCryptoMaterialOf(S3ObjectWrapper s3w) { // Check if encryption info is in object metadata if (s3w.hasEncryptionInfo()) { return ContentCryptoMaterial .fromObjectMetadata(s3w.getObjectMetadata(), kekMaterialsProvider, cryptoConfig.getCryptoProvider(), false, // existing CEK not necessarily key-wrapped kms ); } final S3ObjectWrapper origIfile = fetchInstructionFile(s3w.getS3ObjectId(), null); if (origIfile == null) { throw new IllegalArgumentException( "S3 object is not encrypted: " + s3w); } if (!origIfile.isInstructionFile()) { throw new AmazonClientException( "Invalid instruction file for S3 object: " + s3w); } final String json = origIfile.toJsonString(); return ccmFromJson(json); } private ContentCryptoMaterial ccmFromJson(String json) { @SuppressWarnings("unchecked") final Map instruction = Collections.unmodifiableMap( JsonUtils.jsonToMap(json)); return ContentCryptoMaterial.fromInstructionFile( instruction, kekMaterialsProvider, cryptoConfig.getCryptoProvider(), false, // existing CEK not necessarily key-wrapped kms ); } /** * Creates a get object request for an instruction file using * the default instruction file suffix. * * @param id * an S3 object id (not the instruction file id) * @return * A get request to retrieve an instruction file from S3. */ final GetObjectRequest createInstructionGetRequest(S3ObjectId id) { return createInstructionGetRequest(id, null); } /** * Creates and return a get object request for an instruction file. * * @param s3objectId * an S3 object id (not the instruction file id) * @param instFileSuffix * suffix of the specific instruction file to be used, or null if * the default instruction file is to be used. */ final GetObjectRequest createInstructionGetRequest( S3ObjectId s3objectId, String instFileSuffix) { return new GetObjectRequest( s3objectId.instructionFileId(instFileSuffix)); } static long[] getAdjustedCryptoRange(long[] range) { // If range is invalid, then return null. if (range == null || range[0] > range[1]) { return null; } final long[] adjustedCryptoRange = new long[2]; adjustedCryptoRange[0] = getCipherBlockLowerBound(range[0]); adjustedCryptoRange[1] = getCipherBlockUpperBound(range[1]); return adjustedCryptoRange; } private static long getCipherBlockLowerBound(long leftmostBytePosition) { final long cipherBlockSize = JceEncryptionConstants.SYMMETRIC_CIPHER_BLOCK_SIZE; final long offset = leftmostBytePosition % cipherBlockSize; final long lowerBound = leftmostBytePosition - offset - cipherBlockSize; return lowerBound < 0 ? 0 : lowerBound; } /** * Takes the position of the rightmost desired byte of a user specified * range and returns the position of the end of the following cipher block; * or {@value Long#MAX_VALUE} if the resultant position has a value that * exceeds {@value Long#MAX_VALUE}. */ private static long getCipherBlockUpperBound(final long rightmostBytePosition) { final long cipherBlockSize = JceEncryptionConstants.SYMMETRIC_CIPHER_BLOCK_SIZE; final long offset = cipherBlockSize - (rightmostBytePosition % cipherBlockSize); final long upperBound = rightmostBytePosition + offset + cipherBlockSize; return upperBound < 0 ? Long.MAX_VALUE : upperBound; } }





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