javax.crypto.KeyGenerator — clojure-interop/javax.crypto 1.0.5

This class provides the functionality of a secret (symmetric) key generator.

Key generators are constructed using one of the getInstance class methods of this class.

KeyGenerator objects are reusable, i.e., after a key has been generated, the same KeyGenerator object can be re-used to generate further keys.

There are two ways to generate a key: in an algorithm-independent manner, and in an algorithm-specific manner. The only difference between the two is the initialization of the object:

Algorithm-Independent Initialization All key generators share the concepts of a keysize and a source of randomness. There is an init method in this KeyGenerator class that takes these two universally shared types of arguments. There is also one that takes just a keysize argument, and uses the SecureRandom implementation of the highest-priority installed provider as the source of randomness (or a system-provided source of randomness if none of the installed providers supply a SecureRandom implementation), and one that takes just a source of randomness.

Since no other parameters are specified when you call the above algorithm-independent init methods, it is up to the provider what to do about the algorithm-specific parameters (if any) to be associated with each of the keys.

Algorithm-Specific Initialization For situations where a set of algorithm-specific parameters already exists, there are two init methods that have an AlgorithmParameterSpec argument. One also has a SecureRandom argument, while the other uses the SecureRandom implementation of the highest-priority installed provider as the source of randomness (or a system-provided source of randomness if none of the installed providers supply a SecureRandom implementation).

In case the client does not explicitly initialize the KeyGenerator (via a call to an init method), each provider must supply (and document) a default initialization.

Every implementation of the Java platform is required to support the following standard KeyGenerator algorithms with the keysizes in parentheses:

AES (128) DES (56) DESede (168) HmacSHA1 HmacSHA256

These algorithms are described in the KeyGenerator section of the Java Cryptography Architecture Standard Algorithm Name Documentation. Consult the release documentation for your implementation to see if any other algorithms are supported.

*get-instance clj

(*get-instance algorithm)

(*get-instance algorithm provider)

Returns a KeyGenerator object that generates secret keys for the specified algorithm.

A new KeyGenerator object encapsulating the KeyGeneratorSpi implementation from the specified provider is returned. The specified provider must be registered in the security provider list.

Note that the list of registered providers may be retrieved via the Security.getProviders() method.

algorithm - the standard name of the requested key algorithm. See the KeyGenerator section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard algorithm names. - java.lang.String provider - the name of the provider. - java.lang.String

returns: the new KeyGenerator object. - javax.crypto.KeyGenerator

throws: java.lang.NullPointerException - if the specified algorithm is null.

generate-key clj

(generate-key this)

Generates a secret key.

returns: the new key - javax.crypto.SecretKey

get-algorithm clj

(get-algorithm this)

Returns the algorithm name of this KeyGenerator object.

This is the same name that was specified in one of the getInstance calls that created this KeyGenerator object.

returns: the algorithm name of this KeyGenerator object. - java.lang.String

get-provider clj

(get-provider this)

Returns the provider of this KeyGenerator object.

returns: the provider of this KeyGenerator object - java.security.Provider

init clj

(init this random)

(init this params random)

Initializes this key generator with the specified parameter set and a user-provided source of randomness.

params - the key generation parameters - java.security.spec.AlgorithmParameterSpec random - the source of randomness for this key generator - java.security.SecureRandom

throws: java.security.InvalidAlgorithmParameterException - if params is inappropriate for this key generator