/*
* Copyright 2013-2014 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 static com.amazonaws.util.Throwables.failure;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.InputStream;
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;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import com.amazonaws.AmazonClientException;
import com.amazonaws.AmazonServiceException;
import com.amazonaws.AmazonWebServiceRequest;
import com.amazonaws.auth.AWSCredentialsProvider;
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.Mimetypes;
import com.amazonaws.services.s3.internal.S3Direct;
import com.amazonaws.services.s3.model.AbortMultipartUploadRequest;
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.UploadPartRequest;
import com.amazonaws.services.s3.model.UploadPartResult;
import com.amazonaws.util.LengthCheckInputStream;
import com.amazonaws.util.json.Jackson;
/**
* Common implementation for different S3 cryptographic modules.
*/
public abstract class S3CryptoModuleBase<T extends MultipartUploadCryptoContext>
extends S3CryptoModule<T> {
private static final boolean IS_MULTI_PART = true;
protected static final int DEFAULT_BUFFER_SIZE = 1024*2; // 2K
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<String, T> multipartUploadContexts =
Collections.synchronizedMap(new HashMap<String,T>());
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) {
appendUserAgent(req, USER_AGENT);
return cryptoConfig.getStorageMode() == InstructionFile
? putObjectUsingInstructionFile(req)
: putObjectUsingMetadata(req);
}
private PutObjectResult putObjectUsingMetadata(PutObjectRequest req) {
ContentCryptoMaterial cekMaterial = createContentCryptoMaterial(req);
// Wraps the object data with a cipher input stream
final File fileOrig = req.getFile();
final InputStream isOrig = req.getInputStream();
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
ContentCryptoMaterial cekMaterial = createContentCryptoMaterial(putObjectRequest);
// Wraps the object data with a cipher input stream; note the metadata
// is mutated as a side effect.
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) {
String uploadId = copyPartRequest.getUploadId();
T uploadContext = multipartUploadContexts.get(uploadId);
CopyPartResult result = s3.copyPart(copyPartRequest);
if (!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
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));
}
InitiateMultipartUploadResult result = s3.initiateMultipartUpload(req);
T uploadContext = newUploadContext(req, cekMaterial);
if (req instanceof MaterialsDescriptionProvider) {
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 <I extends CipherLiteInputStream> SdkFilterInputStream wrapForMultipart(
I is, long partSize);
abstract void updateUploadContext(T uploadContext, SdkFilterInputStream is);
/**
* {@inheritDoc}
*
* <p>
* <b>NOTE:</b> 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());
CipherLite cipherLite = cipherLiteForNextPart(uploadContext);
final File fileOrig = req.getFile();
final InputStream isOrig = req.getInputStream();
SdkFilterInputStream isCurr = null;
try {
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
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)
: new RenewableCipherLiteInputStream(isCurr, cipherLite,
DEFAULT_BUFFER_SIZE,
IS_MULTI_PART);
} catch (Exception e) {
cleanupDataSource(req, fileOrig, isOrig, isCurr, log);
throw failure(e,"Unable to create cipher input stream");
}
}
@Override
public CompleteMultipartUploadResult completeMultipartUploadSecurely(
CompleteMultipartUploadRequest req) {
appendUserAgent(req, USER_AGENT);
String uploadId = req.getUploadId();
T uploadContext = multipartUploadContexts.get(uploadId);
if (uploadContext.hasFinalPartBeenSeen() == false) {
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.");
}
CompleteMultipartUploadResult result = s3.completeMultipartUpload(req);
// In InstructionFile mode, we want to write the instruction file only
// after the whole upload has completed correctly.
if (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) {
Mimetypes mimetypes = Mimetypes.getInstance();
metadata.setContentType(mimetypes.getMimetype(file));
}
return instruction.toObjectMetadata(metadata, cryptoConfig.getCryptoMode());
}
protected final ContentCryptoMaterial createContentCryptoMaterial(
AmazonWebServiceRequest req) {
if (req instanceof EncryptionMaterialsFactory) {
// per request level encryption materials
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
MaterialsDescriptionProvider mdp = (MaterialsDescriptionProvider) req;
return newContentCryptoMaterial(this.kekMaterialsProvider,
mdp.getMaterialsDescription(),
cryptoConfig.getCryptoProvider(), req);
}
// per s3 client level encryption materails
return newContentCryptoMaterial(this.kekMaterialsProvider,
cryptoConfig.getCryptoProvider(), req);
}
/**
* Generates and returns the content encryption material with the given kek
* material, material description and security providers.
*/
private ContentCryptoMaterial newContentCryptoMaterial(
EncryptionMaterialsProvider kekMaterialProvider,
Map<String, String> materialsDescription, Provider provider,
AmazonWebServiceRequest req) {
EncryptionMaterials kekMaterials =
kekMaterialProvider.getEncryptionMaterials(materialsDescription);
return buildContentCryptoMaterial(kekMaterials, provider, req);
}
/**
* Generates and returns the content encryption material with the given kek
* material and security providers.
*/
private ContentCryptoMaterial newContentCryptoMaterial(
EncryptionMaterialsProvider kekMaterialProvider,
Provider provider, AmazonWebServiceRequest req) {
EncryptionMaterials kekMaterials = kekMaterialProvider.getEncryptionMaterials();
if (kekMaterials == null)
throw new AmazonClientException("No material available from the encryption material provider");
return buildContentCryptoMaterial(kekMaterials, provider, req);
}
private ContentCryptoMaterial buildContentCryptoMaterial(
EncryptionMaterials kekMaterials, Provider provider,
AmazonWebServiceRequest req) {
// Randomly generate the IV
final byte[] iv = new byte[contentCryptoScheme.getIVLengthInBytes()];
cryptoScheme.getSecureRandom().nextBytes(iv);
if (kekMaterials.isKMSEnabled()) {
GenerateDataKeyRequest keyGenReq = new GenerateDataKeyRequest()
.withEncryptionContext(kekMaterials.getMaterialsDescription())
.withKeyId(kekMaterials.getCustomerMasterKeyId())
.withKeySpec(contentCryptoScheme.getKeySpec());
keyGenReq
.withGeneralProgressListener(req.getGeneralProgressListener())
.withRequestMetricCollector(req.getRequestMetricCollector())
;
GenerateDataKeyResult keyGenRes = kms.generateDataKey(keyGenReq);
final SecretKey cek =
new SecretKeySpec(copyAllBytesFrom(keyGenRes.getPlaintext()),
contentCryptoScheme.getKeyGeneratorAlgorithm());
byte[] keyBlob = copyAllBytesFrom(keyGenRes.getCiphertextBlob());
return ContentCryptoMaterial.wrap(cek, iv,
kekMaterials, contentCryptoScheme, provider,
new KMSSecuredCEK(keyBlob));
} else {
// Generate a one-time use symmetric key and initialize a cipher to encrypt object data
return ContentCryptoMaterial.create(
generateCEK(kekMaterials, provider),
iv, kekMaterials, cryptoScheme, provider, kms, req);
}
}
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;
KeyPair keypair = kekMaterials.getKeyPair();
if (keypair != null) {
String keyWrapAlgo = cryptoScheme.getKeyWrapScheme().getKeyWrapAlgorithm(keypair.getPublic());
if (keyWrapAlgo == null) {
Provider provider = generator.getProvider();
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 < 9; 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 (NoSuchAlgorithmException e) {
throw new AmazonClientException(
"Unable to generate envelope symmetric key:"
+ e.getMessage(), e);
}
}
/**
* Returns a request that has the content as input stream wrapped with a
* cipher, and configured with some meta data and user metadata.
*/
protected final PutObjectRequest wrapWithCipher(
PutObjectRequest 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(
PutObjectRequest req, ContentCryptoMaterial cekMaterial,
long plaintextLength) {
final File fileOrig = req.getFile();
final InputStream isOrig = req.getInputStream();
InputStream isCurr = null;
try {
if (fileOrig == null) {
isCurr = 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 (Exception e) {
cleanupDataSource(req, fileOrig, isOrig, isCurr, log);
throw failure(e, "Unable to create cipher input stream");
}
}
/**
* Returns the plaintext length from the request and metadata; or -1 if
* unknown.
*/
protected final long plaintextLength(PutObjectRequest 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) {
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) {
byte[] bytes = cekMaterial.toJsonString(cryptoConfig.getCryptoMode())
.getBytes(UTF8);
InputStream is = new ByteArrayInputStream(bytes);
ObjectMetadata metadata = new ObjectMetadata();
metadata.setContentLength(bytes.length);
metadata.addUserMetadata(Headers.CRYPTO_INSTRUCTION_FILE, "");
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 extends AmazonWebServiceRequest> 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 {
S3Object o = s3.getObject(
createInstructionGetRequest(s3ObjectId, instFileSuffix));
return o == null ? null : new S3ObjectWrapper(o, s3ObjectId);
} catch (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.");
}
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);
}
PutObjectRequest putInstFileRequest = req.createPutObjectRequest(retrieved);
// Put the new instruction file into S3
return s3.putObject(updateInstructionPutRequest(putInstFileRequest, newCCM));
} catch (RuntimeException ex) {
// If we're unable to set up the decryption, make sure we close the
// HTTP connection
closeQuietly(retrieved, log);
throw ex;
} catch (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
);
}
S3ObjectWrapper orig_ifile =
fetchInstructionFile(s3w.getS3ObjectId(), null);
if (orig_ifile == null) {
throw new IllegalArgumentException(
"S3 object is not encrypted: " + s3w);
}
if (!orig_ifile.isInstructionFile()) {
throw new AmazonClientException(
"Invalid instruction file for S3 object: " + s3w);
}
String json = orig_ifile.toJsonString();
@SuppressWarnings("unchecked")
Map<String, String> instruction = Collections.unmodifiableMap(
Jackson.fromJsonString(json, Map.class));
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;
}
long[] adjustedCryptoRange = new long[2];
adjustedCryptoRange[0] = getCipherBlockLowerBound(range[0]);
adjustedCryptoRange[1] = getCipherBlockUpperBound(range[1]);
return adjustedCryptoRange;
}
private static long getCipherBlockLowerBound(long leftmostBytePosition) {
long cipherBlockSize = JceEncryptionConstants.SYMMETRIC_CIPHER_BLOCK_SIZE;
long offset = leftmostBytePosition % cipherBlockSize;
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) {
long cipherBlockSize = JceEncryptionConstants.SYMMETRIC_CIPHER_BLOCK_SIZE;
long offset = cipherBlockSize - (rightmostBytePosition % cipherBlockSize);
long upperBound = rightmostBytePosition + offset + cipherBlockSize;
return upperBound < 0 ? Long.MAX_VALUE : upperBound;
}
}