Padding

```
public interface Padding
```
Padding interface. This interface is implemented by general-purpose padding schemes, such as the one described in PKCS#5.

Method Summary

Methods
Modifier and Type	Method and Description
`int`	`pad(byte[] in, int off, int len)` Performs padding for the given data input.
`int`	`padLength(int len)` Determines how long the padding will be for a given input length.
`void`	`padWithLen(byte[] in, int off, int len)` Adds the given number of padding bytes to the data input.
`int`	`unpad(byte[] in, int off, int len)` Returns the index where padding starts.

- Method Detail
  - pad
```
int pad(byte[] in,
      int off,
      int len)
        throws javax.crypto.ShortBufferException
```
    Performs padding for the given data input. The padding bytes are appended to the data input.
    
    Parameters:
    in - the input buffer with the data to pad
    off - the offset in in where the data to pad starts
    len - the length of the data to pad
    
    Returns:
    the number of padding bytes appended
    
    Throws:
    
    javax.crypto.ShortBufferException - if in is too small to hold the padding bytes
  - padWithLen
```
void padWithLen(byte[] in,
              int off,
              int len)
                throws javax.crypto.ShortBufferException
```
    Adds the given number of padding bytes to the data input. The value of the padding bytes is determined by the specific padding mechanism that implements this interface.
    
    Parameters:
    in - the input buffer with the data to pad
    the - offset in in where the padding bytes are appended
    len - the number of padding bytes to add
    
    Throws:
    
    javax.crypto.ShortBufferException - if in is too small to hold the padding bytes
  - unpad
```
int unpad(byte[] in,
        int off,
        int len)
```
    Returns the index where padding starts.
    Given a buffer with data and their padding, this method returns the index where the padding starts.
    
    Parameters:
    in - the buffer with the data and their padding
    off - the offset in in where the data starts
    len - the length of the data and their padding
    
    Returns:
    the index where the padding starts, or -1 if the input is not properly padded
  - padLength
```
int padLength(int len)
```
    Determines how long the padding will be for a given input length.
    
    Parameters:
    len - the length of the data to pad
    
    Returns:
    the length of the padding

pad

padWithLen

unpad

padLength