com.microsoft.azure.storage.queue.QueueEncryptionPolicy Maven / Gradle / Ivy
/**
* Copyright Microsoft Corporation
*
* Licensed 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 com.microsoft.azure.storage.queue;
import java.util.HashMap;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.lang3.tuple.Pair;
import com.microsoft.azure.keyvault.core.IKey;
import com.microsoft.azure.keyvault.core.IKeyResolver;
import com.microsoft.azure.storage.Constants;
import com.microsoft.azure.storage.StorageErrorCodeStrings;
import com.microsoft.azure.storage.StorageException;
import com.microsoft.azure.storage.core.Base64;
import com.microsoft.azure.storage.core.EncryptionAgent;
import com.microsoft.azure.storage.core.EncryptionAlgorithm;
import com.microsoft.azure.storage.core.EncryptionData;
import com.microsoft.azure.storage.core.SR;
import com.microsoft.azure.storage.core.Utility;
import com.microsoft.azure.storage.core.WrappedContentKey;
/**
* Represents a queue encryption policy that is used to perform envelope encryption/decryption of Azure queue messages.
*/
public final class QueueEncryptionPolicy {
/**
* An object of type {@link IKey} that is used to wrap/unwrap the content key during encryption.
*/
public IKey keyWrapper;
/**
* The {@link IKeyResolver} used to select the correct key for decrypting existing queue messages.
*/
public IKeyResolver keyResolver;
/**
* Initializes a new instance of the {@link QueueEncryptionPolicy} class with the specified key and resolver.
*
* If the generated policy is intended to be used for encryption, users are expected to provide a key at the
* minimum. The absence of key will cause an exception to be thrown during encryption. If the generated policy is
* intended to be used for decryption, users can provide a keyResolver. The client library will - 1. Invoke the key
* resolver if specified to get the key. 2. If resolver is not specified but a key is specified, match the key id on
* the key and use it.
*
* @param key
* An object of type {@link IKey} that is used to wrap/unwrap the content encryption key.
* @param keyResolver
* The key resolver used to select the correct key for decrypting existing queue messages.
*/
public QueueEncryptionPolicy(IKey key, IKeyResolver keyResolver) {
this.keyWrapper = key;
this.keyResolver = keyResolver;
}
/**
* Gets the {@link IKey} that is used to wrap/unwrap the content key during encryption.
*
* @return An {@link IKey} object.
*/
public IKey getKey() {
return this.keyWrapper;
}
/**
* Gets the key resolver used to select the correct key for decrypting existing queue messages.
*
* @return A resolver that returns an {@link IKey} given a keyId.
*/
public IKeyResolver getKeyResolver() {
return this.keyResolver;
}
/**
* Sets the {@link IKey} that is used to wrap/unwrap the content key during encryption.
*
* @param key
* An {@link IKey} object.
*/
public void setKey(IKey key) {
this.keyWrapper = key;
}
/**
* Sets the key resolver used to select the correct key for decrypting existing queue messages.
*
* @param keyResolver
* A resolver that returns an {@link IKey} given a keyId.
*/
public void setKeyResolver(IKeyResolver keyResolver) {
this.keyResolver = keyResolver;
}
/**
* Return an encrypted base64 encoded message along with encryption related metadata given a plain text message.
*
* @param inputMessage
* The input message in bytes.
* @return The encrypted message that will be uploaded to the service.
* @throws StorageException
* An exception representing any error which occurred during the operation.
*/
String encryptMessage(byte[] inputMessage) throws StorageException {
Utility.assertNotNull("inputMessage", inputMessage);
if (this.keyWrapper == null)
{
throw new IllegalArgumentException(SR.KEY_MISSING);
}
CloudQueueEncryptedMessage encryptedMessage = new CloudQueueEncryptedMessage();
EncryptionData encryptionData = new EncryptionData();
if (encryptionData.getKeyWrappingMetadata() == null) {
encryptionData.setKeyWrappingMetadata(new HashMap());
}
encryptionData.getKeyWrappingMetadata().put("EncryptionLibrary", "Java " + Constants.HeaderConstants.USER_AGENT_VERSION);
encryptionData.setEncryptionAgent(new EncryptionAgent(
Constants.EncryptionConstants.ENCRYPTION_PROTOCOL_V1, EncryptionAlgorithm.AES_CBC_256));
try {
KeyGenerator keyGen = KeyGenerator.getInstance("AES");
keyGen.init(256);
Cipher myAes = Cipher.getInstance("AES/CBC/PKCS5Padding");
SecretKey aesKey = keyGen.generateKey();
myAes.init(Cipher.ENCRYPT_MODE, aesKey);
// Wrap key
Pair encryptedKey = this.keyWrapper
.wrapKeyAsync(aesKey.getEncoded(), null /* algorithm */).get();
encryptionData.setWrappedContentKey(new WrappedContentKey(this.keyWrapper.getKid(), encryptedKey.getKey(),
encryptedKey.getValue()));
encryptedMessage.setEncryptedMessageContents(new String(
Base64.encode(myAes.doFinal(inputMessage, 0, inputMessage.length))));
encryptionData.setContentEncryptionIV(myAes.getIV());
encryptedMessage.setEncryptionData(encryptionData);
return encryptedMessage.serialize();
}
catch (Exception e) {
throw StorageException.translateClientException(e);
}
}
/**
* Returns a plain text message given an encrypted message.
*
* @param inputMessage
* The encrypted message.
* @param requireEncryption
* A value to indicate that the data read from the server should be encrypted.
* @return The plain text message bytes.
* @throws StorageException
* An exception representing any error which occurred during the operation.
*/
byte[] decryptMessage(String inputMessage, Boolean requireEncryption) throws StorageException {
Utility.assertNotNull("inputMessage", inputMessage);
try
{
CloudQueueEncryptedMessage encryptedMessage = CloudQueueEncryptedMessage.deserialize(inputMessage);
if (requireEncryption != null && requireEncryption && encryptedMessage.getEncryptionData() == null) {
throw new StorageException(StorageErrorCodeStrings.DECRYPTION_ERROR,
SR.ENCRYPTION_DATA_NOT_PRESENT_ERROR, null);
}
if (encryptedMessage.getEncryptionData() != null) {
EncryptionData encryptionData = encryptedMessage.getEncryptionData();
Utility.assertNotNull("contentEncryptionIV", encryptionData.getContentEncryptionIV());
Utility.assertNotNull("encryptedKey", encryptionData.getWrappedContentKey().getEncryptedKey());
// Throw if the encryption protocol on the message doesn't match the version that this client library understands
// and is able to decrypt.
if (!Constants.EncryptionConstants.ENCRYPTION_PROTOCOL_V1.equals(encryptionData.getEncryptionAgent()
.getProtocol())) {
throw new StorageException(StorageErrorCodeStrings.DECRYPTION_ERROR,
SR.ENCRYPTION_PROTOCOL_VERSION_INVALID, null);
}
// Throw if neither the key nor the key resolver are set.
if (this.keyWrapper == null && this.keyResolver == null) {
throw new StorageException(StorageErrorCodeStrings.DECRYPTION_ERROR, SR.KEY_AND_RESOLVER_MISSING,
null);
}
byte[] contentEncryptionKey = null;
// 1. Invoke the key resolver if specified to get the key. If the resolver is specified but does not have a
// mapping for the key id, an error should be thrown. This is important for key rotation scenario.
// 2. If resolver is not specified but a key is specified, match the key id on the key and and use it.
// Calling UnwrapKeyAsync synchronously is fine because for the storage client scenario, unwrap happens
// locally. No service call is made.
if (this.keyResolver != null) {
IKey keyEncryptionKey = this.keyResolver.resolveKeyAsync(encryptionData.getWrappedContentKey()
.getKeyId()).get();
Utility.assertNotNull("keyEncryptionKey", keyEncryptionKey);
contentEncryptionKey = keyEncryptionKey.unwrapKeyAsync(
encryptionData.getWrappedContentKey().getEncryptedKey(),
encryptionData.getWrappedContentKey().getAlgorithm()).get();
}
else {
if (encryptionData.getWrappedContentKey().getKeyId().equals(this.keyWrapper.getKid())) {
contentEncryptionKey = this.keyWrapper.unwrapKeyAsync(
encryptionData.getWrappedContentKey().getEncryptedKey(),
encryptionData.getWrappedContentKey().getAlgorithm()).get();
}
else {
throw new StorageException(StorageErrorCodeStrings.DECRYPTION_ERROR, SR.KEY_MISMATCH, null);
}
}
switch (encryptionData.getEncryptionAgent().getEncryptionAlgorithm()) {
case AES_CBC_256:
Cipher myAes = Cipher.getInstance("AES/CBC/PKCS5Padding");
IvParameterSpec ivParameterSpec = new IvParameterSpec(encryptionData.getContentEncryptionIV());
SecretKey keySpec = new SecretKeySpec(contentEncryptionKey, 0, contentEncryptionKey.length,
"AES");
myAes.init(Cipher.DECRYPT_MODE, keySpec,ivParameterSpec);
byte[] src = Base64.decode(encryptedMessage.getEncryptedMessageContents());
return myAes.doFinal(src, 0, src.length);
default:
throw new StorageException(StorageErrorCodeStrings.DECRYPTION_ERROR,
SR.INVALID_ENCRYPTION_ALGORITHM, null);
}
}
else {
return Base64.decode(encryptedMessage.getEncryptedMessageContents());
}
}
catch (StorageException ex) {
throw ex;
}
catch (Exception ex) {
throw new StorageException(StorageErrorCodeStrings.DECRYPTION_ERROR, SR.DECRYPTION_LOGIC_ERROR, ex);
}
}
}