iaik.pkcs.pkcs1

Class PKCS1v15Padding

java.lang.Object

iaik.pkcs.pkcs1.Padding

iaik.pkcs.pkcs1.PKCS1v15Padding

public final class PKCS1v15Padding
extends Padding

PKCS#1v1.5 padding.
This class implements the PKCS#1v1.5 padding scheme as used by the PKCS#1/ RSAES-PKCS1-v_1 encryption and RSASSA-PKCS1-v1_5 signature algorithms.

Version:

File Revision 13

Field Summary

Fields inherited from class iaik.pkcs.pkcs1.Padding

modLen_, opMode_, PADDING_NONE, PADDING_OAEP, PADDING_PKCS1, PADDING_PKCS1_SSL2, privateKey_, publicKey_

Constructor Summary

Constructors

Constructor and Description
PKCS1v15Padding(java.lang.String paddingName, java.lang.String transformationMode) Creates a PKCS#1v1.5 Padding object with given padding name and transformationMode.

Method Summary

Methods

Modifier and Type	Method and Description
java.security.AlgorithmParameters	getParameters() Returns null since no parameters are used.
void	init(int paddingMode, java.security.Key key, int modLen, java.security.spec.AlgorithmParameterSpec params, java.security.SecureRandom random) Initializes this Padding engine.
byte[]	pad(byte[] data) Pads the supplied data according to PKCS#1v1.5.
byte[]	unpad(byte[] paddedData) Unpads the supplied padded data according to PKCS#1v1.5.

Methods inherited from class java.lang.Object

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

Constructor Detail

PKCS1v15Padding

public PKCS1v15Padding(java.lang.String paddingName,
               java.lang.String transformationMode)
                throws javax.crypto.NoSuchPaddingException

Creates a PKCS#1v1.5 Padding object with given padding name and transformationMode.

The transformationMode is the "mode" specification of the transformation string that has to be specified when instantiating a Cipher object. For RSA Ciphers that use PKCS#1v1.5 padding the mode name may be "ECB", "NONE" or the blockType number (0, 1, or 2), e.g.:

 Cipher.getInstance("RSA/ECB/PKCS1Padding");
 

or

 Cipher.getInstance("RSA/bt/PKCS1Padding");
 

where bt is 0, 1 or 2.
If "ECB" or "NONE" is specified as transformation mode, the blockType will be automatically selected as 2 for public key encryption/ private key decryption and 1 for private key encryption/ public key decryption.

Parameters:

paddingName - the name of the padding scheme ("PKCS1Padding" or "PKCS1PaddingSSL2")

transformationMode - the transformation mode name ("ECB", "NONE" or "0", "1" or "2")

Throws:

javax.crypto.NoSuchPaddingException - if the transformationMode is not "ECB" or "NONE" but specifies an illegal block type

Method Detail

init

public void init(int paddingMode,
        java.security.Key key,
        int modLen,
        java.security.spec.AlgorithmParameterSpec params,
        java.security.SecureRandom random)
          throws java.security.InvalidKeyException,
                 java.security.InvalidAlgorithmParameterException

Initializes this Padding engine.

Overrides:

init in class Padding

Parameters:

paddingMode - the padding mode, either PAD_MODE (1) or UNPAD_MODE (2)

key - the RSA en/decryption key; used for checking block type conformance

modLen - the length of the key modulus

params - parameters; ignored since not required for PKCS#1v1.5 padding

random - generator supplying random numbers if required

Throws:

java.security.InvalidKeyException - if the key does not match to the padding block type

java.security.InvalidAlgorithmParameterException - if the parameters are invalid, or the padding Mode is invalid (not PAD_MODE (1) or UNPAD_MODE (2), or SSL2 padding variant is requested in UNPAD mode which is not supported

getParameters

public java.security.AlgorithmParameters getParameters()

Returns null since no parameters are used.

Specified by:

getParameters in class Padding

pad

public byte[] pad(byte[] data)
           throws javax.crypto.BadPaddingException

Pads the supplied data according to PKCS#1v1.5.

Specified by:

pad in class Padding

Parameters:

data - the data to be padded

Returns:

the padded data

Throws:

javax.crypto.BadPaddingException - if an error occurs during padding the data

unpad

public byte[] unpad(byte[] paddedData)
             throws javax.crypto.BadPaddingException

Unpads the supplied padded data according to PKCS#1v1.5. The contents of the paddedData input array maybe changed after calling this method.

Specified by:

unpad in class Padding

Parameters:

paddedData - the data to be unpadded;

Returns:

the unpadded data

Throws:

javax.crypto.BadPaddingException - if the padding was invalid