Package org.apache.shiro.crypto

Class AesCipherService

java.lang.Object

org.apache.shiro.crypto.JcaCipherService

org.apache.shiro.crypto.AbstractSymmetricCipherService

org.apache.shiro.crypto.DefaultBlockCipherService

org.apache.shiro.crypto.AesCipherService

All Implemented Interfaces:

CipherService

public class AesCipherService
extends DefaultBlockCipherService

CipherService using the AES cipher algorithm for all encryption, decryption, and key operations.

The AES algorithm can support key sizes of 128, 192 and 256 bits*. This implementation defaults to 128 bits.

Note that this class retains changes the parent class's default CBC mode to GCM of operation instead of the typical JDK default of ECB. ECB should not be used in security-sensitive environments because ECB does not allow for initialization vectors, which are considered necessary for strong encryption. See the parent class's JavaDoc and the JcaCipherService JavaDoc for more on why the JDK default should not be used and is not used in this implementation.

* Generating and using AES key sizes greater than 128 require installation of the Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy files.

Since:

1.0

Constructor Summary

Constructors

Constructor	Description
AesCipherService()	Creates a new CipherService instance using the AES cipher algorithm with the following important cipher default attributes: Attribute Value keySize 128 bits blockSize 128 bits (required for AES mode GCM* paddingScheme NoPadding*** initializationVectorSize 128 bits generateInitializationVectors true**

Method Summary

Modifier and Type	Method	Description
protected AlgorithmParameterSpec	createParameterSpec(byte[] iv, boolean streaming)

Methods inherited from class org.apache.shiro.crypto.DefaultBlockCipherService

generateInitializationVector, getBlockSize, getModeName, getPaddingSchemeName, getStreamingBlockSize, getStreamingModeName, getStreamingPaddingSchemeName, getTransformationString, isGenerateInitializationVectors, setBlockSize, setMode, setModeName, setPaddingScheme, setPaddingSchemeName, setStreamingBlockSize, setStreamingMode, setStreamingModeName, setStreamingPaddingScheme, setStreamingPaddingSchemeName

Methods inherited from class org.apache.shiro.crypto.AbstractSymmetricCipherService

generateNewKey, generateNewKey

Methods inherited from class org.apache.shiro.crypto.JcaCipherService

decrypt, decrypt, encrypt, encrypt, ensureSecureRandom, getAlgorithmName, getDefaultSecureRandom, getInitializationVectorSize, getKeySize, getSecureRandom, getStreamingBufferSize, isGenerateInitializationVectors, setGenerateInitializationVectors, setInitializationVectorSize, setKeySize, setSecureRandom, setStreamingBufferSize

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AesCipherService

public AesCipherService()

Creates a new CipherService instance using the AES cipher algorithm with the following important cipher default attributes:

Attribute	Value
keySize	128 bits
blockSize	128 bits (required for AES
mode	GCM*
paddingScheme	NoPadding***
initializationVectorSize	128 bits
generateInitializationVectors	true**

* The GCM operation mode is used instead of the JDK default ECB to ensure strong encryption. ECB should not be used in security-sensitive environments - see the DefaultBlockCipherService class JavaDoc's "Operation Mode" section for more.

**In conjunction with the default GCM operation mode, initialization vectors are generated by default to ensure strong encryption. See the JcaCipherService class JavaDoc for more.

**Since GCM is a stream cipher, padding is implemented in the operation mode and an external padding scheme cannot be used in conjunction with GCM. In fact, AES/GCM/PKCS5Padding is just an alias in most JVM for AES/GCM/NoPadding.

Method Detail

createParameterSpec

protected AlgorithmParameterSpec createParameterSpec(byte[] iv,
                                                     boolean streaming)

Overrides:

createParameterSpec in class JcaCipherService