Module java.base
Package javax.crypto

## Class EncryptedPrivateKeyInfo

- java.lang.Object
- - javax.crypto.EncryptedPrivateKeyInfo

-     public class EncryptedPrivateKeyInfo
      extends Object

  This class implements the `EncryptedPrivateKeyInfo` type as defined in PKCS #8.

  Its ASN.1 definition is as follows:

       EncryptedPrivateKeyInfo ::=  SEQUENCE {
           encryptionAlgorithm   AlgorithmIdentifier,
           encryptedData   OCTET STRING }

       AlgorithmIdentifier  ::=  SEQUENCE  {
           algorithm              OBJECT IDENTIFIER,
           parameters             ANY DEFINED BY algorithm OPTIONAL  }

  Since:
    1.4
  See Also:
    `PKCS8EncodedKeySpec`

- - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `EncryptedPrivateKeyInfo​(byte[] encoded)` | Constructs (i.e., parses) an `EncryptedPrivateKeyInfo` from its ASN.1 encoding.
    `EncryptedPrivateKeyInfo​(String algName, byte[] encryptedData)` | Constructs an `EncryptedPrivateKeyInfo` from the encryption algorithm name and the encrypted data.
    `EncryptedPrivateKeyInfo​(AlgorithmParameters algParams, byte[] encryptedData)` | Constructs an `EncryptedPrivateKeyInfo` from the encryption algorithm parameters and the encrypted data.

  - ### Method Summary

    Modifier and Type | Method | Description
    --- | --- | ---
    `String` | `getAlgName()` | Returns the encryption algorithm.
    `AlgorithmParameters` | `getAlgParameters()` | Returns the algorithm parameters used by the encryption algorithm.
    `byte[]` | `getEncoded()` | Returns the ASN.1 encoding of this object.
    `byte[]` | `getEncryptedData()` | Returns the encrypted data.
    `PKCS8EncodedKeySpec` | `getKeySpec​(Key decryptKey)` | Extract the enclosed PKCS8EncodedKeySpec object from the encrypted data and return it.
    `PKCS8EncodedKeySpec` | `getKeySpec​(Key decryptKey, String providerName)` | Extract the enclosed PKCS8EncodedKeySpec object from the encrypted data and return it.
    `PKCS8EncodedKeySpec` | `getKeySpec​(Key decryptKey, Provider provider)` | Extract the enclosed PKCS8EncodedKeySpec object from the encrypted data and return it.
    `PKCS8EncodedKeySpec` | `getKeySpec​(Cipher cipher)` | Extract the enclosed PKCS8EncodedKeySpec object from the encrypted data and return it.

    - ### Methods declared in class java.lang.Object

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

- - ### Constructor Detail

    - #### EncryptedPrivateKeyInfo

          public EncryptedPrivateKeyInfo​(byte[] encoded)
                                  throws IOException

      Constructs (i.e., parses) an `EncryptedPrivateKeyInfo` from its ASN.1 encoding.
      Parameters:
        `encoded` - the ASN.1 encoding of this object. The contents of the array are copied to protect against subsequent modification.
      Throws:
        `NullPointerException` - if the `encoded` is null.
        `IOException` - if error occurs when parsing the ASN.1 encoding.

    - #### EncryptedPrivateKeyInfo

          public EncryptedPrivateKeyInfo​(String algName,
                                         byte[] encryptedData)
                                  throws NoSuchAlgorithmException

      Constructs an `EncryptedPrivateKeyInfo` from the encryption algorithm name and the encrypted data.

      Note: This constructor will use null as the value of the algorithm parameters. If the encryption algorithm has parameters whose value is not null, a different constructor, e.g. EncryptedPrivateKeyInfo(AlgorithmParameters, byte[]), should be used.

      Parameters:
        `algName` - encryption algorithm name. See the Java Security Standard Algorithm Names document for information about standard Cipher algorithm names.
        `encryptedData` - encrypted data. The contents of `encrypedData` are copied to protect against subsequent modification when constructing this object.
      Throws:
        `NullPointerException` - if `algName` or `encryptedData` is null.
        `IllegalArgumentException` - if `encryptedData` is empty, i.e. 0-length.
        `NoSuchAlgorithmException` - if the specified algName is not supported.

    - #### EncryptedPrivateKeyInfo

          public EncryptedPrivateKeyInfo​(AlgorithmParameters algParams,
                                         byte[] encryptedData)
                                  throws NoSuchAlgorithmException

      Constructs an `EncryptedPrivateKeyInfo` from the encryption algorithm parameters and the encrypted data.
      Parameters:
        `algParams` - the algorithm parameters for the encryption algorithm. `algParams.getEncoded()` should return the ASN.1 encoded bytes of the `parameters` field of the `AlgorithmIdentifer` component of the `EncryptedPrivateKeyInfo` type.
        `encryptedData` - encrypted data. The contents of `encrypedData` are copied to protect against subsequent modification when constructing this object.
      Throws:
        `NullPointerException` - if `algParams` or `encryptedData` is null.
        `IllegalArgumentException` - if `encryptedData` is empty, i.e. 0-length.
        `NoSuchAlgorithmException` - if the specified algName of the specified `algParams` parameter is not supported.

  - ### Method Detail

    - #### getAlgName

          public String getAlgName()

      Returns the encryption algorithm.

      Note: Standard name is returned instead of the specified one in the constructor when such mapping is available. See the Java Security Standard Algorithm Names document for information about standard Cipher algorithm names.

      Returns:
        the encryption algorithm name.

    - #### getAlgParameters

          public AlgorithmParameters getAlgParameters()

      Returns the algorithm parameters used by the encryption algorithm.
      Returns:
        the algorithm parameters.

    - #### getEncryptedData

          public byte[] getEncryptedData()

      Returns the encrypted data.
      Returns:
        the encrypted data. Returns a new array each time this method is called.

    - #### getKeySpec

          public PKCS8EncodedKeySpec getKeySpec​(Cipher cipher)
                                         throws InvalidKeySpecException

      Extract the enclosed PKCS8EncodedKeySpec object from the encrypted data and return it.
      Note: In order to successfully retrieve the enclosed PKCS8EncodedKeySpec object, `cipher` needs to be initialized to either Cipher.DECRYPT_MODE or Cipher.UNWRAP_MODE, with the same key and parameters used for generating the encrypted data.
      Parameters:
        `cipher` - the initialized cipher object which will be used for decrypting the encrypted data.
      Returns:
        the PKCS8EncodedKeySpec object.
      Throws:
        `NullPointerException` - if `cipher` is null.
        `InvalidKeySpecException` - if the given cipher is inappropriate for the encrypted data or the encrypted data is corrupted and cannot be decrypted.

    - #### getKeySpec

          public PKCS8EncodedKeySpec getKeySpec​(Key decryptKey)
                                         throws NoSuchAlgorithmException,
                                                InvalidKeyException

      Extract the enclosed PKCS8EncodedKeySpec object from the encrypted data and return it.
      Parameters:
        `decryptKey` - key used for decrypting the encrypted data.
      Returns:
        the PKCS8EncodedKeySpec object.
      Throws:
        `NullPointerException` - if `decryptKey` is null.
        `NoSuchAlgorithmException` - if cannot find appropriate cipher to decrypt the encrypted data.
        `InvalidKeyException` - if `decryptKey` cannot be used to decrypt the encrypted data or the decryption result is not a valid PKCS8KeySpec.
      Since:
        1.5

    - #### getKeySpec

          public PKCS8EncodedKeySpec getKeySpec​(Key decryptKey,
                                                String providerName)
                                         throws NoSuchProviderException,
                                                NoSuchAlgorithmException,
                                                InvalidKeyException

      Extract the enclosed PKCS8EncodedKeySpec object from the encrypted data and return it.
      Parameters:
        `decryptKey` - key used for decrypting the encrypted data.
        `providerName` - the name of provider whose Cipher implementation will be used.
      Returns:
        the PKCS8EncodedKeySpec object.
      Throws:
        `NullPointerException` - if `decryptKey` or `providerName` is null.
        `NoSuchProviderException` - if no provider `providerName` is registered.
        `NoSuchAlgorithmException` - if cannot find appropriate cipher to decrypt the encrypted data.
        `InvalidKeyException` - if `decryptKey` cannot be used to decrypt the encrypted data or the decryption result is not a valid PKCS8KeySpec.
      Since:
        1.5

    - #### getKeySpec

          public PKCS8EncodedKeySpec getKeySpec​(Key decryptKey,
                                                Provider provider)
                                         throws NoSuchAlgorithmException,
                                                InvalidKeyException

      Extract the enclosed PKCS8EncodedKeySpec object from the encrypted data and return it.
      Parameters:
        `decryptKey` - key used for decrypting the encrypted data.
        `provider` - the name of provider whose Cipher implementation will be used.
      Returns:
        the PKCS8EncodedKeySpec object.
      Throws:
        `NullPointerException` - if `decryptKey` or `provider` is null.
        `NoSuchAlgorithmException` - if cannot find appropriate cipher to decrypt the encrypted data in `provider`.
        `InvalidKeyException` - if `decryptKey` cannot be used to decrypt the encrypted data or the decryption result is not a valid PKCS8KeySpec.
      Since:
        1.5

    - #### getEncoded

          public byte[] getEncoded()
                            throws IOException

      Returns the ASN.1 encoding of this object.
      Returns:
        the ASN.1 encoding. Returns a new array each time this method is called.
      Throws:
        `IOException` - if error occurs when constructing its ASN.1 encoding.