Package org.mozilla.jss.crypto

Class Cipher

  • public abstract class Cipher
extends java.lang.Object
    A context for performing symmetric encryption and decryption. First, the context must be initialized. Then, it can be updated with input through zero or more calls to update. Finally, doFinal is called to finalize the operation. Note that it is not necessary to call update if all of the data is available at once. In this case, all of the input can be processed with one call to doFinal.

    • Constructor Summary

      Constructors 
      Constructor Description
      Cipher()  

    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      abstract byte[] doFinal()
      Completes an cipher operation.
      abstract byte[] doFinal​(byte[] bytes)
      Completes an cipher operation.
      abstract byte[] doFinal​(byte[] bytes, int offset, int length)
      Completes an cipher operation.
      abstract void initDecrypt​(SymmetricKey key)
      Initializes a decryption context with a symmetric key.
      abstract void initDecrypt​(SymmetricKey key, java.security.spec.AlgorithmParameterSpec parameters)
      Initializes a decryption context with a symmetric key and algorithm parameters.
      abstract void initEncrypt​(SymmetricKey key)
      Initializes a encryption context with a symmetric key.
      abstract void initEncrypt​(SymmetricKey key, java.security.spec.AlgorithmParameterSpec parameters)
      Initializes an encryption context with a symmetric key and algorithm parameters.
      static byte[] pad​(byte[] toBePadded, int blockSize)
      Pads a byte array so that its length is a multiple of the given blocksize.
      static byte[] unPad​(byte[] padded)
      Un-pads a byte array that is padded with PKCS padding.
      static byte[] unPad​(byte[] padded, int blockSize)
      Un-pads a byte array that is padded with PKCS padding.
      abstract byte[] update​(byte[] bytes)
      Updates the encryption context with additional input.
      abstract byte[] update​(byte[] bytes, int offset, int length)
      Updates the encryption context with additional plaintext.

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • Cipher

        public Cipher()

    • Method Detail

      • initEncrypt

        public abstract void initEncrypt​(SymmetricKey key)
                          throws java.security.InvalidKeyException,
                                 java.security.InvalidAlgorithmParameterException,
                                 TokenException
        Initializes a encryption context with a symmetric key.
        Throws:
        java.security.InvalidKeyException
        java.security.InvalidAlgorithmParameterException
        TokenException

      • initDecrypt

        public abstract void initDecrypt​(SymmetricKey key)
                          throws java.security.InvalidKeyException,
                                 java.security.InvalidAlgorithmParameterException,
                                 TokenException
        Initializes a decryption context with a symmetric key.
        Throws:
        java.security.InvalidKeyException
        java.security.InvalidAlgorithmParameterException
        TokenException

      • initEncrypt

        public abstract void initEncrypt​(SymmetricKey key,
                                 java.security.spec.AlgorithmParameterSpec parameters)
                          throws java.security.InvalidKeyException,
                                 java.security.InvalidAlgorithmParameterException,
                                 TokenException
        Initializes an encryption context with a symmetric key and algorithm parameters.
        Throws:
        java.security.InvalidKeyException
        java.security.InvalidAlgorithmParameterException
        TokenException

      • initDecrypt

        public abstract void initDecrypt​(SymmetricKey key,
                                 java.security.spec.AlgorithmParameterSpec parameters)
                          throws java.security.InvalidKeyException,
                                 java.security.InvalidAlgorithmParameterException,
                                 TokenException
        Initializes a decryption context with a symmetric key and algorithm parameters.
        Throws:
        java.security.InvalidKeyException
        java.security.InvalidAlgorithmParameterException
        TokenException

      • update

        public abstract byte[] update​(byte[] bytes)
                       throws java.lang.IllegalStateException,
                              TokenException
        Updates the encryption context with additional input.
        Parameters:
        bytes - Bytes of plaintext (if encrypting) or ciphertext (if decrypting).
        Returns:
        Bytes of ciphertext (if encrypting) or plaintext (if decrypting).
        Throws:
        java.lang.IllegalStateException
        TokenException

      • update

        public abstract byte[] update​(byte[] bytes,
                              int offset,
                              int length)
                       throws java.lang.IllegalStateException,
                              TokenException
        Updates the encryption context with additional plaintext.
        Parameters:
        bytes - Bytes of plaintext (if encrypting) or ciphertext (if decrypting).
        offset - The index in bytes at which to begin reading.
        length - The number of bytes from bytes to read.
        Returns:
        Bytes of ciphertext (if encrypting) or plaintext (if decrypting).
        Throws:
        java.lang.IllegalStateException
        TokenException

      • doFinal

        public abstract byte[] doFinal​(byte[] bytes)
                        throws java.lang.IllegalStateException,
                               IllegalBlockSizeException,
                               javax.crypto.BadPaddingException,
                               TokenException
        Completes an cipher operation. This can be called directly after the context is initialized, or update may be called any number of times before calling final.
        Parameters:
        bytes - Bytes of plaintext (if encrypting) or ciphertext (if decrypting).
        Returns:
        The last of the output.
        Throws:
        java.lang.IllegalStateException
        IllegalBlockSizeException
        javax.crypto.BadPaddingException
        TokenException

      • doFinal

        public abstract byte[] doFinal​(byte[] bytes,
                               int offset,
                               int length)
                        throws java.lang.IllegalStateException,
                               IllegalBlockSizeException,
                               javax.crypto.BadPaddingException,
                               TokenException
        Completes an cipher operation.
        Parameters:
        bytes - Bytes of plaintext (if encrypting) or ciphertext (if decrypting).
        offset - The index in bytes at which to begin reading.
        length - The number of bytes from bytes to read.
        Returns:
        The last of the output.
        Throws:
        java.lang.IllegalStateException
        IllegalBlockSizeException
        javax.crypto.BadPaddingException
        TokenException

      • pad

        public static byte[] pad​(byte[] toBePadded,
                         int blockSize)
        Pads a byte array so that its length is a multiple of the given blocksize. The method of padding is the one defined in the RSA PKCS standards. If M is the length of the data and B is the block size, the padding string consists of B - (M mod B) octets, each having the value B - (M mod B).
        Parameters:
        toBePadded - The byte array to pad.
        blockSize - The block size of the encryption algorithm. Must be greater than zero.
        See Also:
        unPad(byte[], int)

      • unPad

        public static byte[] unPad​(byte[] padded,
                           int blockSize)
                    throws javax.crypto.BadPaddingException
        Un-pads a byte array that is padded with PKCS padding.
        Parameters:
        blockSize - The block size of the encryption algorithm. This is only used for error checking: if the pad size is not between 1 and blockSize, a BadPaddingException is thrown.
        Throws:
        javax.crypto.BadPaddingException
        See Also:
        pad(byte[], int)

      • unPad

        public static byte[] unPad​(byte[] padded)
                    throws javax.crypto.BadPaddingException
        Un-pads a byte array that is padded with PKCS padding. Since this version does not take block size as a parameter, it cannot error check.
        Throws:
        javax.crypto.BadPaddingException
        See Also:
        pad(byte[], int)