AESEngine (Javadocs [I2P+ 2.13.0+] - API Version 0.9.70+)

java.lang.Object
- net.i2p.crypto.AESEngine

Direct Known Subclasses:
CryptixAESEngine
```
public class AESEngine
extends Object
```
Abstract base class for AES cipher operations in I2P. This class provides the interface and common functionality for AES encryption and decryption operations. The base implementation contains placeholder methods that log warnings when called. The actual AES implementation is provided by CryptixAESEngine which extends this class.
This design pattern allows for:
- Consistent API across different AES implementations
- Graceful fallback when AES is unavailable
- Easy swapping of underlying AES providers
See Also:
CryptixAESEngine

Field Summary
Fields
Modifier and Type Field and Description
protected I2PAppContext _context
I2P application context
protected Log _log
Logger instance

Fields
Modifier and Type	Field and Description
`protected I2PAppContext`	`_context` I2P application context
`protected Log`	`_log` Logger instance

Constructor Summary
Constructors
Modifier Constructor and Description
protected AESEngine(I2PAppContext ctx)
Constructor for subclasses.

Constructors
Modifier	Constructor and Description
`protected`	`AESEngine(I2PAppContext ctx)` Constructor for subclasses.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`decrypt(byte[] payload, int payloadIndex, byte[] out, int outIndex, SessionKey sessionKey, byte[] iv, int length)` Decrypt the data with the session key
`void`	`decrypt(byte[] payload, int payloadIndex, byte[] out, int outIndex, SessionKey sessionKey, byte[] iv, int ivOffset, int length)` Decrypt the data with the session key.
`void`	`decryptBlock(byte[] payload, int inIndex, SessionKey sessionKey, byte[] rv, int outIndex)` This just copies payload to rv, see extension for the real thing.
`void`	`encrypt(byte[] payload, int payloadIndex, byte[] out, int outIndex, SessionKey sessionKey, byte[] iv, int length)` Encrypt the payload with the session key
`void`	`encrypt(byte[] payload, int payloadIndex, byte[] out, int outIndex, SessionKey sessionKey, byte[] iv, int ivOffset, int length)` Encrypt payload with session key.
`void`	`encryptBlock(byte[] payload, int inIndex, SessionKey sessionKey, byte[] out, int outIndex)` This just copies payload to out, see extension for the real thing.
`static byte[]`	`getPadding(I2PAppContext context, int curSize, long minPaddedSize)` Return random bytes for padding the data to a mod 16 size so that it is at least minPaddedSize Public for ElGamalAESEngine.
`static int`	`getPaddingSize(int curSize, long minPaddedSize)` Return size for padding the data to a mod 16 size so that it is at least minPaddedSize Public for ElGamalAESEngine.
`byte[]`	`safeDecrypt(byte[] payload, SessionKey sessionKey, byte[] iv)` See safeEncrypt() for description.
`byte[]`	`safeEncrypt(byte[] payload, SessionKey sessionKey, byte[] iv, int paddedSize)` Encrypt SHA-256 Hash of IV, 4 byte length, and payload, with random padding up to paddedSize, rounded up to next multiple of 16.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - _context
```
protected final I2PAppContext _context
```
    I2P application context
  - _log
```
protected final Log _log
```
    Logger instance
- Constructor Detail
  - AESEngine
```
protected AESEngine(I2PAppContext ctx)
```
    Constructor for subclasses.
    Parameters:
    ctx - I2P application context
- Method Detail
  - decrypt
```
public void decrypt(byte[] payload,
                    int payloadIndex,
                    byte[] out,
                    int outIndex,
                    SessionKey sessionKey,
                    byte[] iv,
                    int length)
```
    Decrypt the data with the session key
    Parameters:
    payload - data to be decrypted
    payloadIndex - index into the payload to start decrypting
    out - where to store the cleartext
    outIndex - where in out to start writing
    sessionKey - private session key to decrypt to
    iv - IV for CBC
    length - how much data to decrypt
  - decrypt
```
public void decrypt(byte[] payload,
                    int payloadIndex,
                    byte[] out,
                    int outIndex,
                    SessionKey sessionKey,
                    byte[] iv,
                    int ivOffset,
                    int length)
```
    Decrypt the data with the session key. This just copies payload to out, see extension for the real thing.
    Parameters:
    payload - data to be decrypted
    payloadIndex - index into the payload to start decrypting
    out - where to store the cleartext
    outIndex - where in out to start writing
    sessionKey - private session key to decrypt to
    iv - IV for CBC
    ivOffset - offset into IV
    length - how much data to decrypt
  - decryptBlock
```
public void decryptBlock(byte[] payload,
                         int inIndex,
                         SessionKey sessionKey,
                         byte[] rv,
                         int outIndex)
```
    This just copies payload to rv, see extension for the real thing.
    Parameters:
    payload - encrypted data
    inIndex - starting index in payload
    sessionKey - private session key
    rv - output buffer
    outIndex - starting index in output
  - encrypt
```
public void encrypt(byte[] payload,
                    int payloadIndex,
                    byte[] out,
                    int outIndex,
                    SessionKey sessionKey,
                    byte[] iv,
                    int length)
```
    Encrypt the payload with the session key
    Parameters:
    payload - data to be encrypted
    payloadIndex - index into the payload to start encrypting
    out - where to store the result
    outIndex - where in out to start writing
    sessionKey - private esession key to encrypt to
    iv - IV for CBC, must be 16 bytes
    length - how much data to encrypt
  - encrypt
```
public void encrypt(byte[] payload,
                    int payloadIndex,
                    byte[] out,
                    int outIndex,
                    SessionKey sessionKey,
                    byte[] iv,
                    int ivOffset,
                    int length)
```
    Encrypt payload with session key. This just copies payload to out, see extension for the real thing.
    Parameters:
    payload - data to be encrypted
    payloadIndex - index into payload to start encrypting
    out - where to store result
    outIndex - where in out to start writing
    sessionKey - private session key to encrypt to
    iv - IV for CBC
    ivOffset - offset into IV
    length - how much data to encrypt
  - encryptBlock
```
public void encryptBlock(byte[] payload,
                         int inIndex,
                         SessionKey sessionKey,
                         byte[] out,
                         int outIndex)
```
    This just copies payload to out, see extension for the real thing.
    Parameters:
    payload - data to encrypt
    inIndex - starting index in payload
    sessionKey - unused
    out - output buffer
    outIndex - starting index in output
  - getPadding
```
public static final byte[] getPadding(I2PAppContext context,
                                      int curSize,
                                      long minPaddedSize)
```
    Return random bytes for padding the data to a mod 16 size so that it is at least minPaddedSize Public for ElGamalAESEngine. Not a public API, not for external use.
    Parameters:
    context - I2P application context
    curSize - current data size
    minPaddedSize - minimum padded size
    Returns:
    padding bytes
  - getPaddingSize
```
public static final int getPaddingSize(int curSize,
                                       long minPaddedSize)
```
    Return size for padding the data to a mod 16 size so that it is at least minPaddedSize Public for ElGamalAESEngine. Not a public API, not for external use.
    Parameters:
    curSize - current data size
    minPaddedSize - minimum padded size
    Returns:
    padding size required
  - safeDecrypt
```
public byte[] safeDecrypt(byte[] payload,
                          SessionKey sessionKey,
                          byte[] iv)
```
    See safeEncrypt() for description. WARNING - no check for maximum length here, OOM DOS possible, fix it if you're going to use this.
    Parameters:
    payload - data to be decrypted
    sessionKey - session key for decryption
    iv - IV for CBC, must be 16 bytes
    Returns:
    decrypted data or null on error Obsolete — prefer decrypt(byte[], int, byte[], int, SessionKey, byte[], int).
  - safeEncrypt
```
public byte[] safeEncrypt(byte[] payload,
                          SessionKey sessionKey,
                          byte[] iv,
                          int paddedSize)
```
    Encrypt SHA-256 Hash of IV, 4 byte length, and payload, with random padding up to paddedSize, rounded up to next multiple of 16.
    Parameters:
    payload - data to be encrypted
    sessionKey - session key for encryption
    iv - IV for CBC, must be 16 bytes
    paddedSize - minimum size of output
    Returns:
    encrypted data or null on error Obsolete — prefer encrypt(byte[], int, byte[], int, SessionKey, byte[], int).

Class AESEngine

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

_context

_log

Constructor Detail

AESEngine

Method Detail

decrypt

decrypt

decryptBlock

encrypt

encrypt

encryptBlock

getPadding

getPaddingSize

safeDecrypt

safeEncrypt