Added in API level 1

SecretKeyFactory

open class SecretKeyFactory
kotlin.Any
   ↳ javax.crypto.SecretKeyFactory

This class represents a factory for secret keys.

Key factories are used to convert keys (opaque cryptographic keys of type Key) into key specifications (transparent representations of the underlying key material), and vice versa. Secret key factories operate only on secret (symmetric) keys.

Key factories are bi-directional, i.e., they allow to build an opaque key object from a given key specification (key material), or to retrieve the underlying key material of a key object in a suitable format.

Application developers should refer to their provider's documentation to find out which key specifications are supported by the generateSecret and getKeySpec methods. For example, the DES secret-key factory supplied by the "SunJCE" provider supports DESKeySpec as a transparent representation of DES keys, and that provider's secret-key factory for Triple DES keys supports DESedeKeySpec as a transparent representation of Triple DES keys.

Android provides the following SecretKeyFactory algorithms:

Algorithm Supported API Levels
AES 23+
DES 1+
DESede 1+
HmacSHA1 23+
HmacSHA224 23+
HmacSHA256 23+
HmacSHA384 23+
HmacSHA512 23+
PBEwithHmacSHA1 1+
PBEwithHmacSHA1AndAES_128 26+
PBEwithHmacSHA1AndAES_256 26+
PBEwithHmacSHA224AndAES_128 26+
PBEwithHmacSHA224AndAES_256 26+
PBEwithHmacSHA256AndAES_128 26+
PBEwithHmacSHA256AndAES_256 26+
PBEwithHmacSHA384AndAES_128 26+
PBEwithHmacSHA384AndAES_256 26+
PBEwithHmacSHA512AndAES_128 26+
PBEwithHmacSHA512AndAES_256 26+
PBEwithMD5AND128BITAES-CBC-OPENSSL 1+
PBEwithMD5AND192BITAES-CBC-OPENSSL 1+
PBEwithMD5AND256BITAES-CBC-OPENSSL 1+
PBEwithMD5ANDDES 1+
PBEwithMD5ANDRC2 1+
PBEwithSHA1ANDDES 1+
PBEwithSHA1ANDRC2 1+
PBEwithSHA256AND128BITAES-CBC-BC 1+
PBEwithSHA256AND192BITAES-CBC-BC 1+
PBEwithSHA256AND256BITAES-CBC-BC 1+
PBEwithSHAAND128BITAES-CBC-BC 1+
PBEwithSHAAND128BITRC2-CBC 10+
PBEwithSHAAND128BITRC4 10+
PBEwithSHAAND192BITAES-CBC-BC 1+
PBEwithSHAAND2-KEYTRIPLEDES-CBC 1+
PBEwithSHAAND256BITAES-CBC-BC 1+
PBEwithSHAAND3-KEYTRIPLEDES-CBC 1+
PBEwithSHAAND40BITRC2-CBC 1+
PBEwithSHAAND40BITRC4 10+
PBEwithSHAANDTWOFISH-CBC 10+
PBKDF2withHmacSHA1 10+
PBKDF2withHmacSHA1And8BIT 19+
PBKDF2withHmacSHA224 26+
PBKDF2withHmacSHA256 26+
PBKDF2withHmacSHA384 26+
PBKDF2withHmacSHA512 26+
These algorithms are described in the SecretKeyFactory section of the Java Cryptography Architecture Standard Algorithm Name Documentation.

Summary

Protected constructors
SecretKeyFactory(keyFacSpi: SecretKeyFactorySpi!, provider: Provider!, algorithm: String!)

Creates a SecretKeyFactory object.

Public methods
SecretKey!

Generates a SecretKey object from the provided key specification (key material).

String!

Returns the algorithm name of this SecretKeyFactory object.

static SecretKeyFactory!
getInstance(algorithm: String!)

Returns a SecretKeyFactory object that converts secret keys of the specified algorithm.

static SecretKeyFactory!
getInstance(algorithm: String!, provider: String!)

Returns a SecretKeyFactory object that converts secret keys of the specified algorithm.

static SecretKeyFactory!
getInstance(algorithm: String!, provider: Provider!)

Returns a SecretKeyFactory object that converts secret keys of the specified algorithm.

KeySpec!
getKeySpec(key: SecretKey!, keySpec: Class<*>!)

Returns a specification (key material) of the given key object in the requested format.

Provider!

Returns the provider of this SecretKeyFactory object.

SecretKey!

Translates a key object, whose provider may be unknown or potentially untrusted, into a corresponding key object of this secret-key factory.

Protected constructors

SecretKeyFactory

Added in API level 1
protected SecretKeyFactory(
    keyFacSpi: SecretKeyFactorySpi!,
    provider: Provider!,
    algorithm: String!)

Creates a SecretKeyFactory object.

Parameters
keyFacSpi SecretKeyFactorySpi!: the delegate
provider Provider!: the provider
algorithm String!: the secret-key algorithm

Public methods

generateSecret

Added in API level 1
fun generateSecret(keySpec: KeySpec!): SecretKey!

Generates a SecretKey object from the provided key specification (key material).

Parameters
keySpec KeySpec!: the specification (key material) of the secret key
Return
SecretKey! the secret key
Exceptions
java.security.spec.InvalidKeySpecException if the given key specification is inappropriate for this secret-key factory to produce a secret key.

getAlgorithm

Added in API level 1
fun getAlgorithm(): String!

Returns the algorithm name of this SecretKeyFactory object.

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

Return
String! the algorithm name of this SecretKeyFactory object.

getInstance

Added in API level 1
static fun getInstance(algorithm: String!): SecretKeyFactory!

Returns a SecretKeyFactory object that converts secret keys of the specified algorithm.

This method traverses the list of registered security Providers, starting with the most preferred Provider. A new SecretKeyFactory object encapsulating the SecretKeyFactorySpi implementation from the first Provider that supports the specified algorithm is returned.

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

Parameters
algorithm String!: the standard name of the requested secret-key algorithm. See the SecretKeyFactory section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard algorithm names.
Return
SecretKeyFactory! the new SecretKeyFactory object.
Exceptions
java.lang.NullPointerException if the specified algorithm is null.
java.security.NoSuchAlgorithmException if no Provider supports a SecretKeyFactorySpi implementation for the specified algorithm.

getInstance

Added in API level 1
static fun getInstance(
    algorithm: String!,
    provider: String!
): SecretKeyFactory!

Returns a SecretKeyFactory object that converts secret keys of the specified algorithm.

A new SecretKeyFactory object encapsulating the SecretKeyFactorySpi 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.

Parameters
algorithm String!: the standard name of the requested secret-key algorithm. See the SecretKeyFactory section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard algorithm names.
provider String!: the name of the provider.
Return
SecretKeyFactory! the new SecretKeyFactory object.
Exceptions
java.security.NoSuchProviderException if the specified provider is not registered in the security provider list.
java.security.NoSuchAlgorithmException if a SecretKeyFactorySpi implementation for the specified algorithm is not available from the specified provider.
java.lang.NullPointerException if the specified algorithm is null.
java.lang.IllegalArgumentException if the provider is null or empty.

getInstance

Added in API level 1
static fun getInstance(
    algorithm: String!,
    provider: Provider!
): SecretKeyFactory!

Returns a SecretKeyFactory object that converts secret keys of the specified algorithm.

A new SecretKeyFactory object encapsulating the SecretKeyFactorySpi implementation from the specified Provider object is returned. Note that the specified Provider object does not have to be registered in the provider list.

Parameters
algorithm String!: the standard name of the requested secret-key algorithm. See the SecretKeyFactory section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard algorithm names.
provider Provider!: the provider.
Return
SecretKeyFactory! the new SecretKeyFactory object.
Exceptions
java.lang.NullPointerException if the specified algorithm is null.
java.security.NoSuchAlgorithmException if a SecretKeyFactorySpi implementation for the specified algorithm is not available from the specified Provider object.
java.lang.IllegalArgumentException if the provider is null.

getKeySpec

Added in API level 1
fun getKeySpec(
    key: SecretKey!,
    keySpec: Class<*>!
): KeySpec!

Returns a specification (key material) of the given key object in the requested format.

Parameters
key SecretKey!: the key
keySpec Class<*>!: the requested format in which the key material shall be returned
Return
KeySpec! the underlying key specification (key material) in the requested format
Exceptions
java.security.spec.InvalidKeySpecException if the requested key specification is inappropriate for the given key (e.g., the algorithms associated with key and keySpec do not match, or key references a key on a cryptographic hardware device whereas keySpec is the specification of a software-based key), or the given key cannot be dealt with (e.g., the given key has an algorithm or format not supported by this secret-key factory).

getProvider

Added in API level 1
fun getProvider(): Provider!

Returns the provider of this SecretKeyFactory object.

Return
Provider! the provider of this SecretKeyFactory object

translateKey

Added in API level 1
fun translateKey(key: SecretKey!): SecretKey!

Translates a key object, whose provider may be unknown or potentially untrusted, into a corresponding key object of this secret-key factory.

Parameters
key SecretKey!: the key whose provider is unknown or untrusted
Return
SecretKey! the translated key
Exceptions
java.security.InvalidKeyException if the given key cannot be processed by this secret-key factory.