1 package org.bouncycastle.crypto.modes; 2 3 import org.bouncycastle.crypto.BlockCipher; 4 import org.bouncycastle.crypto.CipherParameters; 5 import org.bouncycastle.crypto.DataLengthException; 6 import org.bouncycastle.crypto.InvalidCipherTextException; 7 8 /** 9 * A block cipher mode that includes authenticated encryption with a streaming mode and optional associated data. 10 * <p> 11 * Implementations of this interface may operate in a packet mode (where all input data is buffered and 12 * processed dugin the call to {@link #doFinal(byte[], int)}), or in a streaming mode (where output data is 13 * incrementally produced with each call to {@link #processByte(byte, byte[], int)} or 14 * {@link #processBytes(byte[], int, int, byte[], int)}. 15 * </p> 16 * This is important to consider during decryption: in a streaming mode, unauthenticated plaintext data 17 * may be output prior to the call to {@link #doFinal(byte[], int)} that results in an authentication 18 * failure. The higher level protocol utilising this cipher must ensure the plaintext data is handled 19 * appropriately until the end of data is reached and the entire ciphertext is authenticated. 20 * @see org.bouncycastle.crypto.params.AEADParameters 21 */ 22 public interface AEADBlockCipher 23 { 24 /** 25 * initialise the underlying cipher. Parameter can either be an AEADParameters or a ParametersWithIV object. 26 * 27 * @param forEncryption true if we are setting up for encryption, false otherwise. 28 * @param params the necessary parameters for the underlying cipher to be initialised. 29 * @exception IllegalArgumentException if the params argument is inappropriate. 30 */ init(boolean forEncryption, CipherParameters params)31 public void init(boolean forEncryption, CipherParameters params) 32 throws IllegalArgumentException; 33 34 /** 35 * Return the name of the algorithm. 36 * 37 * @return the algorithm name. 38 */ getAlgorithmName()39 public String getAlgorithmName(); 40 41 /** 42 * return the cipher this object wraps. 43 * 44 * @return the cipher this object wraps. 45 */ getUnderlyingCipher()46 public BlockCipher getUnderlyingCipher(); 47 48 /** 49 * Add a single byte to the associated data check. 50 * <br>If the implementation supports it, this will be an online operation and will not retain the associated data. 51 * 52 * @param in the byte to be processed. 53 */ processAADByte(byte in)54 public void processAADByte(byte in); 55 56 /** 57 * Add a sequence of bytes to the associated data check. 58 * <br>If the implementation supports it, this will be an online operation and will not retain the associated data. 59 * 60 * @param in the input byte array. 61 * @param inOff the offset into the in array where the data to be processed starts. 62 * @param len the number of bytes to be processed. 63 */ processAADBytes(byte[] in, int inOff, int len)64 public void processAADBytes(byte[] in, int inOff, int len); 65 66 /** 67 * encrypt/decrypt a single byte. 68 * 69 * @param in the byte to be processed. 70 * @param out the output buffer the processed byte goes into. 71 * @param outOff the offset into the output byte array the processed data starts at. 72 * @return the number of bytes written to out. 73 * @exception DataLengthException if the output buffer is too small. 74 */ processByte(byte in, byte[] out, int outOff)75 public int processByte(byte in, byte[] out, int outOff) 76 throws DataLengthException; 77 78 /** 79 * process a block of bytes from in putting the result into out. 80 * 81 * @param in the input byte array. 82 * @param inOff the offset into the in array where the data to be processed starts. 83 * @param len the number of bytes to be processed. 84 * @param out the output buffer the processed bytes go into. 85 * @param outOff the offset into the output byte array the processed data starts at. 86 * @return the number of bytes written to out. 87 * @exception DataLengthException if the output buffer is too small. 88 */ processBytes(byte[] in, int inOff, int len, byte[] out, int outOff)89 public int processBytes(byte[] in, int inOff, int len, byte[] out, int outOff) 90 throws DataLengthException; 91 92 /** 93 * Finish the operation either appending or verifying the MAC at the end of the data. 94 * 95 * @param out space for any resulting output data. 96 * @param outOff offset into out to start copying the data at. 97 * @return number of bytes written into out. 98 * @throws IllegalStateException if the cipher is in an inappropriate state. 99 * @throws org.bouncycastle.crypto.InvalidCipherTextException if the MAC fails to match. 100 */ doFinal(byte[] out, int outOff)101 public int doFinal(byte[] out, int outOff) 102 throws IllegalStateException, InvalidCipherTextException; 103 104 /** 105 * Return the value of the MAC associated with the last stream processed. 106 * 107 * @return MAC for plaintext data. 108 */ getMac()109 public byte[] getMac(); 110 111 /** 112 * return the size of the output buffer required for a processBytes 113 * an input of len bytes. 114 * <p> 115 * The returned size may be dependent on the initialisation of this cipher 116 * and may not be accurate once subsequent input data is processed - this method 117 * should be invoked immediately prior to input data being processed. 118 * </p> 119 * 120 * @param len the length of the input. 121 * @return the space required to accommodate a call to processBytes 122 * with len bytes of input. 123 */ getUpdateOutputSize(int len)124 public int getUpdateOutputSize(int len); 125 126 /** 127 * return the size of the output buffer required for a processBytes plus a 128 * doFinal with an input of len bytes. 129 * <p> 130 * The returned size may be dependent on the initialisation of this cipher 131 * and may not be accurate once subsequent input data is processed - this method 132 * should be invoked immediately prior to a call to final processing of input data 133 * and a call to {@link #doFinal(byte[], int)}. 134 * </p> 135 * @param len the length of the input. 136 * @return the space required to accommodate a call to processBytes and doFinal 137 * with len bytes of input. 138 */ getOutputSize(int len)139 public int getOutputSize(int len); 140 141 /** 142 * Reset the cipher. After resetting the cipher is in the same state 143 * as it was after the last init (if there was one). 144 */ reset()145 public void reset(); 146 } 147