javax.crypto

  • The javax.crypto package provides classes for cryptographic operations, including encryption, decryption, key generation, and message authentication.

  • Core functionalities are exposed through key classes like Cipher, KeyAgreement, KeyGenerator, Mac, and SecretKeyFactory.

  • Cipher offers encryption and decryption capabilities, supporting various algorithms and modes of operation.

  • KeyAgreement enables key exchange protocols for secure communication establishment.

  • Several specialized exception classes handle cryptographic errors and exceptional conditions during operations.

Interfaces

SecretKey A secret (symmetric) key. 

Classes

Cipher This class provides the functionality of a cryptographic cipher for encryption and decryption. 
CipherInputStream A CipherInputStream is composed of an InputStream and a Cipher so that read() methods return data that are read in from the underlying InputStream but have been additionally processed by the Cipher. 
CipherOutputStream A CipherOutputStream is composed of an OutputStream and a Cipher so that write() methods first process the data before writing them out to the underlying OutputStream. 
CipherSpi This class defines the Service Provider Interface (SPI) for the Cipher class. 
ExemptionMechanism This class provides the functionality of an exemption mechanism, examples of which are key recovery, key weakening, and key escrow. 
ExemptionMechanismSpi This class defines the Service Provider Interface (SPI) for the ExemptionMechanism class. 
KeyAgreement This class provides the functionality of a key agreement (or key exchange) protocol. 
KeyAgreementSpi This class defines the Service Provider Interface (SPI) for the KeyAgreement class. 
KeyGenerator This class provides the functionality of a secret (symmetric) key generator. 
KeyGeneratorSpi This class defines the Service Provider Interface (SPI) for the KeyGenerator class. 
Mac This class provides the functionality of a "Message Authentication Code" (MAC) algorithm. 
MacSpi This class defines the Service Provider Interface (SPI) for the Mac class. 
NullCipher The NullCipher class is a class that provides an "identity cipher" -- one that does not transform the plain text. 
SealedObject This class enables a programmer to create an object and protect its confidentiality with a cryptographic algorithm. 
SecretKeyFactory This class represents a factory for secret keys. 
SecretKeyFactorySpi This class defines the Service Provider Interface (SPI) for the SecretKeyFactory class. 

Exceptions

AEADBadTagException This exception is thrown when a Cipher operating in an AEAD mode (such as GCM/CCM) is unable to verify the supplied authentication tag. 
BadPaddingException This exception is thrown when a particular padding mechanism is expected for the input data but the data is not padded properly. 
ExemptionMechanismException This is the generic ExemptionMechanism exception. 
IllegalBlockSizeException This exception is thrown when the length of data provided to a block cipher is incorrect, i.e., does not match the block size of the cipher. 
NoSuchPaddingException This exception is thrown when a particular padding mechanism is requested but is not available in the environment. 
ShortBufferException This exception is thrown when an output buffer provided by the user is too short to hold the operation result.