AEADBlockCipher.java revision e1142c149e244797ce73b0e7fad40816e447a817 
1package org.bouncycastle.crypto.modes;
2
3import org.bouncycastle.crypto.BlockCipher;
4import org.bouncycastle.crypto.CipherParameters;
5import org.bouncycastle.crypto.DataLengthException;
6import org.bouncycastle.crypto.InvalidCipherTextException;
7
8/**
9 * A block cipher mode that includes authenticated encryption with a streaming mode and optional associated data.
10 * @see org.bouncycastle.crypto.params.AEADParameters
11 */
12public interface AEADBlockCipher
13{
14    /**
15     * initialise the underlying cipher. Parameter can either be an AEADParameters or a ParametersWithIV object.
16     *
17     * @param forEncryption true if we are setting up for encryption, false otherwise.
18     * @param params the necessary parameters for the underlying cipher to be initialised.
19     * @exception IllegalArgumentException if the params argument is inappropriate.
20     */
21    public void init(boolean forEncryption, CipherParameters params)
22        throws IllegalArgumentException;
23
24    /**
25     * Return the name of the algorithm.
26     *
27     * @return the algorithm name.
28     */
29    public String getAlgorithmName();
30
31    /**
32     * return the cipher this object wraps.
33     *
34     * @return the cipher this object wraps.
35     */
36    public BlockCipher getUnderlyingCipher();
37
38    /**
39     * Add a single byte to the associated data check.
40     * <br>If the implementation supports it, this will be an online operation and will not retain the associated data.
41     *
42     * @param in the byte to be processed.
43     */
44    public void processAADByte(byte in);
45
46    /**
47     * Add a sequence of bytes to the associated data check.
48     * <br>If the implementation supports it, this will be an online operation and will not retain the associated data.
49     *
50     * @param in the input byte array.
51     * @param inOff the offset into the in array where the data to be processed starts.
52     * @param len the number of bytes to be processed.
53     */
54    public void processAADBytes(byte[] in, int inOff, int len);
55
56    /**
57     * encrypt/decrypt a single byte.
58     *
59     * @param in the byte to be processed.
60     * @param out the output buffer the processed byte goes into.
61     * @param outOff the offset into the output byte array the processed data starts at.
62     * @return the number of bytes written to out.
63     * @exception DataLengthException if the output buffer is too small.
64     */
65    public int processByte(byte in, byte[] out, int outOff)
66        throws DataLengthException;
67
68    /**
69     * process a block of bytes from in putting the result into out.
70     *
71     * @param in the input byte array.
72     * @param inOff the offset into the in array where the data to be processed starts.
73     * @param len the number of bytes to be processed.
74     * @param out the output buffer the processed bytes go into.
75     * @param outOff the offset into the output byte array the processed data starts at.
76     * @return the number of bytes written to out.
77     * @exception DataLengthException if the output buffer is too small.
78     */
79    public int processBytes(byte[] in, int inOff, int len, byte[] out, int outOff)
80        throws DataLengthException;
81
82    /**
83     * Finish the operation either appending or verifying the MAC at the end of the data.
84     *
85     * @param out space for any resulting output data.
86     * @param outOff offset into out to start copying the data at.
87     * @return number of bytes written into out.
88     * @throws IllegalStateException if the cipher is in an inappropriate state.
89     * @throws org.bouncycastle.crypto.InvalidCipherTextException if the MAC fails to match.
90     */
91    public int doFinal(byte[] out, int outOff)
92        throws IllegalStateException, InvalidCipherTextException;
93
94    /**
95     * Return the value of the MAC associated with the last stream processed.
96     *
97     * @return MAC for plaintext data.
98     */
99    public byte[] getMac();
100
101    /**
102     * return the size of the output buffer required for a processBytes
103     * an input of len bytes.
104     *
105     * @param len the length of the input.
106     * @return the space required to accommodate a call to processBytes
107     * with len bytes of input.
108     */
109    public int getUpdateOutputSize(int len);
110
111    /**
112     * return the size of the output buffer required for a processBytes plus a
113     * doFinal with an input of len bytes.
114     *
115     * @param len the length of the input.
116     * @return the space required to accommodate a call to processBytes and doFinal
117     * with len bytes of input.
118     */
119    public int getOutputSize(int len);
120
121    /**
122     * Reset the cipher. After resetting the cipher is in the same state
123     * as it was after the last init (if there was one).
124     */
125    public void reset();
126}
127