Package org.bouncycastle.pqc.jcajce.provider.util

Class AsymmetricBlockCipher

  • Direct Known Subclasses:
    McEliecePKCSCipherSpi
    public abstract class AsymmetricBlockCipher
extends CipherSpiExt
    The AsymmetricBlockCipher class extends CipherSpiExt. NOTE: Some Ciphers are using Padding. OneAndZeroesPadding is used as default padding. However padding can still be specified, but mode is not supported; if you try to instantiate the cipher with something else than "NONE" as mode NoSuchAlgorithmException is thrown.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected java.io.ByteArrayOutputStream buf
      Internal buffer
      protected int cipherTextSize
      The maximum number of bytes the cipher can encrypt.
      protected int maxPlainTextSize
      The maximum number of bytes the cipher can decrypt.
      protected java.security.spec.AlgorithmParameterSpec paramSpec
      ParameterSpec used with this cipher

    • Constructor Summary

      Constructors 
      Constructor Description
      AsymmetricBlockCipher()
      The AsymmetricBlockCipher() constructor

    • Method Summary

      All Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      protected void checkLength​(int inLen)
      Check if the message length plus the length of the input length can be en/decrypted.
      byte[] doFinal​(byte[] input, int inOff, int inLen)
      Finish a multiple-part encryption or decryption operation (depending on how this cipher was initialized).
      int doFinal​(byte[] input, int inOff, int inLen, byte[] output, int outOff)
      Finish a multiple-part encryption or decryption operation (depending on how this cipher was initialized).
      int getBlockSize()
      Return the block size (in bytes).
      byte[] getIV()
      Return the initialization vector.
      int getOutputSize​(int inLen)
      Return the length in bytes that an output buffer would need to be in order to hold the result of the next update or doFinal operation, given the input length inLen (in bytes).
      java.security.spec.AlgorithmParameterSpec getParameters()
      Returns the parameters used with this cipher.
      protected abstract void initCipherDecrypt​(java.security.Key key, java.security.spec.AlgorithmParameterSpec params)
      Initialize the AsymmetricBlockCipher with a certain key for data encryption.
      protected abstract void initCipherEncrypt​(java.security.Key key, java.security.spec.AlgorithmParameterSpec params, java.security.SecureRandom sr)
      Initialize the AsymmetricBlockCipher with a certain key for data encryption.
      void initDecrypt​(java.security.Key key)
      Initialize the cipher for decryption by forwarding it to initDecrypt(Key, AlgorithmParameterSpec).
      void initDecrypt​(java.security.Key key, java.security.spec.AlgorithmParameterSpec params)
      This method initializes the AsymmetricBlockCipher with a certain key for data decryption.
      void initEncrypt​(java.security.Key key)
      Initializes the cipher for encryption by forwarding it to initEncrypt(Key, FlexiSecureRandom).
      void initEncrypt​(java.security.Key key, java.security.SecureRandom random)
      Initialize this cipher for encryption by forwarding it to initEncrypt(Key, FlexiSecureRandom, AlgorithmParameterSpec).
      void initEncrypt​(java.security.Key key, java.security.spec.AlgorithmParameterSpec params)
      Initializes the cipher for encryption by forwarding it to initEncrypt(Key, FlexiSecureRandom, AlgorithmParameterSpec).
      void initEncrypt​(java.security.Key key, java.security.spec.AlgorithmParameterSpec params, java.security.SecureRandom secureRandom)
      This method initializes the AsymmetricBlockCipher with a certain key for data encryption.
      protected abstract byte[] messageDecrypt​(byte[] input)
      Decrypt the ciphertext stored in input.
      protected abstract byte[] messageEncrypt​(byte[] input)
      Encrypt the message stored in input.
      protected void setMode​(java.lang.String modeName)
      Since asymmetric block ciphers do not support modes, this method does nothing.
      protected void setPadding​(java.lang.String paddingName)
      Since asymmetric block ciphers do not support padding, this method does nothing.
      byte[] update​(byte[] input, int inOff, int inLen)
      Continue a multiple-part encryption or decryption operation.
      int update​(byte[] input, int inOff, int inLen, byte[] output, int outOff)
      Continue a multiple-part encryption or decryption operation (depending on how this cipher was initialized), processing another data part.

      • Methods inherited from class javax.crypto.CipherSpi

        engineDoFinal, engineUnwrap, engineUpdate, engineUpdateAAD, engineUpdateAAD, engineWrap

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • paramSpec

        protected java.security.spec.AlgorithmParameterSpec paramSpec
        ParameterSpec used with this cipher

      • buf

        protected java.io.ByteArrayOutputStream buf
        Internal buffer

      • maxPlainTextSize

        protected int maxPlainTextSize
        The maximum number of bytes the cipher can decrypt.

      • cipherTextSize

        protected int cipherTextSize
        The maximum number of bytes the cipher can encrypt.

    • Constructor Detail

      • AsymmetricBlockCipher

        public AsymmetricBlockCipher()
        The AsymmetricBlockCipher() constructor

    • Method Detail

      • getBlockSize

        public final int getBlockSize()
        Return the block size (in bytes). Note: although the ciphers extending this class are not block ciphers, the method was adopted to return the maximal plaintext and ciphertext sizes for non hybrid ciphers. If the cipher is hybrid, it returns 0.
        Specified by:
        getBlockSize in class CipherSpiExt
        Returns:
        if the cipher is not a hybrid one the max plain/cipher text size is returned, otherwise 0 is returned

      • getIV

        public final byte[] getIV()
        Description copied from class: CipherSpiExt
        Return the initialization vector. This is useful in the context of password-based encryption or decryption, where the IV is derived from a user-provided passphrase.
        Specified by:
        getIV in class CipherSpiExt
        Returns:
        null since no initialization vector is used.

      • getOutputSize

        public final int getOutputSize​(int inLen)
        Return the length in bytes that an output buffer would need to be in order to hold the result of the next update or doFinal operation, given the input length inLen (in bytes). This call takes into account any unprocessed (buffered) data from a previous update call, and padding. The actual output length of the next update() or doFinal() call may be smaller than the length returned by this method.

        If the input length plus the length of the buffered data exceeds the maximum length, 0 is returned.

        Specified by:
        getOutputSize in class CipherSpiExt
        Parameters:
        inLen - the length of the input
        Returns:
        the length of the ciphertext or 0 if the input is too long.

      • getParameters

        public final java.security.spec.AlgorithmParameterSpec getParameters()
        Returns the parameters used with this cipher.

        The returned parameters may be the same that were used to initialize this cipher, or may contain the default set of parameters or a set of randomly generated parameters used by the underlying cipher implementation (provided that the underlying cipher implementation uses a default set of parameters or creates new parameters if it needs parameters but was not initialized with any).

        Specified by:
        getParameters in class CipherSpiExt
        Returns:
        the parameters used with this cipher, or null if this cipher does not use any parameters.

      • initEncrypt

        public final void initEncrypt​(java.security.Key key)
                       throws java.security.InvalidKeyException
        Initializes the cipher for encryption by forwarding it to initEncrypt(Key, FlexiSecureRandom).

        If this cipher requires any algorithm parameters that cannot be derived from the given key, the underlying cipher implementation is supposed to generate the required parameters itself (using provider-specific default or random values) if it is being initialized for encryption, and raise an InvalidKeyException if it is being initialized for decryption. The generated parameters can be retrieved using engineGetParameters or engineGetIV (if the parameter is an IV).

        Parameters:
        key - the encryption or decryption key.
        Throws:
        java.security.InvalidKeyException - if the given key is inappropriate for initializing this cipher.

      • initEncrypt

        public final void initEncrypt​(java.security.Key key,
                              java.security.SecureRandom random)
                       throws java.security.InvalidKeyException
        Initialize this cipher for encryption by forwarding it to initEncrypt(Key, FlexiSecureRandom, AlgorithmParameterSpec).

        If this cipher requires any algorithm parameters that cannot be derived from the given key, the underlying cipher implementation is supposed to generate the required parameters itself (using provider-specific default or random values) if it is being initialized for encryption, and raise an InvalidKeyException if it is being initialized for decryption. The generated parameters can be retrieved using engineGetParameters or engineGetIV (if the parameter is an IV).

        Parameters:
        key - the encryption or decryption key.
        random - the source of randomness.
        Throws:
        java.security.InvalidKeyException - if the given key is inappropriate for initializing this cipher.

      • initEncrypt

        public final void initEncrypt​(java.security.Key key,
                              java.security.spec.AlgorithmParameterSpec params)
                       throws java.security.InvalidKeyException,
                              java.security.InvalidAlgorithmParameterException
        Initializes the cipher for encryption by forwarding it to initEncrypt(Key, FlexiSecureRandom, AlgorithmParameterSpec).
        Parameters:
        key - the encryption or decryption key.
        params - the algorithm parameters.
        Throws:
        java.security.InvalidKeyException - if the given key is inappropriate for initializing this cipher.
        java.security.InvalidAlgorithmParameterException - if the given algortihm parameters are inappropriate for this cipher, or if this cipher is being initialized for decryption and requires algorithm parameters and params is null.

      • initEncrypt

        public final void initEncrypt​(java.security.Key key,
                              java.security.spec.AlgorithmParameterSpec params,
                              java.security.SecureRandom secureRandom)
                       throws java.security.InvalidKeyException,
                              java.security.InvalidAlgorithmParameterException
        This method initializes the AsymmetricBlockCipher with a certain key for data encryption.

        If this cipher (including its underlying feedback or padding scheme) requires any random bytes (e.g., for parameter generation), it will get them from random.

        Note that when a Cipher object is initialized, it loses all previously-acquired state. In other words, initializing a Cipher is equivalent to creating a new instance of that Cipher and initializing it

        Specified by:
        initEncrypt in class CipherSpiExt
        Parameters:
        key - the key which has to be used to encrypt data.
        secureRandom - the source of randomness.
        params - the algorithm parameters.
        Throws:
        java.security.InvalidKeyException - if the given key is inappropriate for initializing this cipher
        java.security.InvalidAlgorithmParameterException - if the given algorithm parameters are inappropriate for this cipher, or if this cipher is being initialized for decryption and requires algorithm parameters and params is null.

      • initDecrypt

        public final void initDecrypt​(java.security.Key key)
                       throws java.security.InvalidKeyException
        Initialize the cipher for decryption by forwarding it to initDecrypt(Key, AlgorithmParameterSpec).

        If this cipher requires any algorithm parameters that cannot be derived from the given key, the underlying cipher implementation is supposed to generate the required parameters itself (using provider-specific default or random values) if it is being initialized for encryption, and raise an InvalidKeyException if it is being initialized for decryption. The generated parameters can be retrieved using engineGetParameters or engineGetIV (if the parameter is an IV).

        Parameters:
        key - the encryption or decryption key.
        Throws:
        java.security.InvalidKeyException - if the given key is inappropriate for initializing this cipher.

      • initDecrypt

        public final void initDecrypt​(java.security.Key key,
                              java.security.spec.AlgorithmParameterSpec params)
                       throws java.security.InvalidKeyException,
                              java.security.InvalidAlgorithmParameterException
        This method initializes the AsymmetricBlockCipher with a certain key for data decryption.

        If this cipher (including its underlying feedback or padding scheme) requires any random bytes (e.g., for parameter generation), it will get them from random.

        Note that when a Cipher object is initialized, it loses all previously-acquired state. In other words, initializing a Cipher is equivalent to creating a new instance of that Cipher and initializing it

        Specified by:
        initDecrypt in class CipherSpiExt
        Parameters:
        key - the key which has to be used to decrypt data.
        params - the algorithm parameters.
        Throws:
        java.security.InvalidKeyException - if the given key is inappropriate for initializing this cipher
        java.security.InvalidAlgorithmParameterException - if the given algorithm parameters are inappropriate for this cipher, or if this cipher is being initialized for decryption and requires algorithm parameters and params is null.

      • update

        public final byte[] update​(byte[] input,
                           int inOff,
                           int inLen)
        Continue a multiple-part encryption or decryption operation. This method just writes the input into an internal buffer.
        Specified by:
        update in class CipherSpiExt
        Parameters:
        input - byte array containing the next part of the input
        inOff - index in the array where the input starts
        inLen - length of the input
        Returns:
        a new buffer with the result (always empty)

      • update

        public final int update​(byte[] input,
                        int inOff,
                        int inLen,
                        byte[] output,
                        int outOff)
        Continue a multiple-part encryption or decryption operation (depending on how this cipher was initialized), processing another data part.
        Specified by:
        update in class CipherSpiExt
        Parameters:
        input - the input buffer
        inOff - the offset where the input starts
        inLen - the input length
        output - the output buffer
        outOff - the offset where the result is stored
        Returns:
        the length of the output (always 0)

      • doFinal

        public final byte[] doFinal​(byte[] input,
                            int inOff,
                            int inLen)
                     throws javax.crypto.IllegalBlockSizeException,
                            javax.crypto.BadPaddingException
        Finish a multiple-part encryption or decryption operation (depending on how this cipher was initialized).
        Specified by:
        doFinal in class CipherSpiExt
        Parameters:
        input - the input buffer
        inOff - the offset where the input starts
        inLen - the input length
        Returns:
        a new buffer with the result
        Throws:
        javax.crypto.IllegalBlockSizeException - if the plaintext or ciphertext size is too large.
        javax.crypto.BadPaddingException - if the ciphertext is invalid.

      • doFinal

        public final int doFinal​(byte[] input,
                         int inOff,
                         int inLen,
                         byte[] output,
                         int outOff)
                  throws javax.crypto.ShortBufferException,
                         javax.crypto.IllegalBlockSizeException,
                         javax.crypto.BadPaddingException
        Finish a multiple-part encryption or decryption operation (depending on how this cipher was initialized).
        Specified by:
        doFinal in class CipherSpiExt
        Parameters:
        input - the input buffer
        inOff - the offset where the input starts
        inLen - the input length
        output - the buffer for the result
        outOff - the offset where the result is stored
        Returns:
        the output length
        Throws:
        javax.crypto.ShortBufferException - if the output buffer is too small to hold the result.
        javax.crypto.IllegalBlockSizeException - if the plaintext or ciphertext size is too large.
        javax.crypto.BadPaddingException - if the ciphertext is invalid.

      • setMode

        protected final void setMode​(java.lang.String modeName)
        Since asymmetric block ciphers do not support modes, this method does nothing.
        Specified by:
        setMode in class CipherSpiExt
        Parameters:
        modeName - the cipher mode (unused)

      • setPadding

        protected final void setPadding​(java.lang.String paddingName)
        Since asymmetric block ciphers do not support padding, this method does nothing.
        Specified by:
        setPadding in class CipherSpiExt
        Parameters:
        paddingName - the name of the padding scheme (not used)

      • checkLength

        protected void checkLength​(int inLen)
                    throws javax.crypto.IllegalBlockSizeException
        Check if the message length plus the length of the input length can be en/decrypted. This method uses the specific values maxPlainTextSize and cipherTextSize which are set by the implementations. If the input length plus the length of the internal buffer is greater than maxPlainTextSize for encryption or not equal to cipherTextSize for decryption, an IllegalBlockSizeException will be thrown.
        Parameters:
        inLen - length of the input to check
        Throws:
        javax.crypto.IllegalBlockSizeException - if the input length is invalid.

      • initCipherEncrypt

        protected abstract void initCipherEncrypt​(java.security.Key key,
                                          java.security.spec.AlgorithmParameterSpec params,
                                          java.security.SecureRandom sr)
                                   throws java.security.InvalidKeyException,
                                          java.security.InvalidAlgorithmParameterException
        Initialize the AsymmetricBlockCipher with a certain key for data encryption.
        Parameters:
        key - the key which has to be used to encrypt data
        params - the algorithm parameters
        sr - the source of randomness
        Throws:
        java.security.InvalidKeyException - if the given key is inappropriate for initializing this cipher.
        java.security.InvalidAlgorithmParameterException - if the given parameters are inappropriate for initializing this cipher.

      • initCipherDecrypt

        protected abstract void initCipherDecrypt​(java.security.Key key,
                                          java.security.spec.AlgorithmParameterSpec params)
                                   throws java.security.InvalidKeyException,
                                          java.security.InvalidAlgorithmParameterException
        Initialize the AsymmetricBlockCipher with a certain key for data encryption.
        Parameters:
        key - the key which has to be used to decrypt data
        params - the algorithm parameters
        Throws:
        java.security.InvalidKeyException - if the given key is inappropriate for initializing this cipher
        java.security.InvalidAlgorithmParameterException - if the given parameters are inappropriate for initializing this cipher.

      • messageEncrypt

        protected abstract byte[] messageEncrypt​(byte[] input)
                                  throws javax.crypto.IllegalBlockSizeException,
                                         javax.crypto.BadPaddingException
        Encrypt the message stored in input. The method should also perform an additional length check.
        Parameters:
        input - the message to be encrypted (usually the message length is less than or equal to maxPlainTextSize)
        Returns:
        the encrypted message (it has length equal to maxCipherTextSize_)
        Throws:
        javax.crypto.IllegalBlockSizeException - if the input is inappropriate for this cipher.
        javax.crypto.BadPaddingException - if the input format is invalid.

      • messageDecrypt

        protected abstract byte[] messageDecrypt​(byte[] input)
                                  throws javax.crypto.IllegalBlockSizeException,
                                         javax.crypto.BadPaddingException
        Decrypt the ciphertext stored in input. The method should also perform an additional length check.
        Parameters:
        input - the ciphertext to be decrypted (the ciphertext length is less than or equal to maxCipherTextSize)
        Returns:
        the decrypted message
        Throws:
        javax.crypto.IllegalBlockSizeException - if the input is inappropriate for this cipher.
        javax.crypto.BadPaddingException - if the input format is invalid.