DERBuffer (Alfresco JLan 5.2 API)

java.lang.Object
- org.alfresco.jlan.server.auth.asn.DERBuffer

```
public class DERBuffer
extends Object
```
DER Buffer Class
Pack/unpack objects from a ASN.1 DER encoded blob.

Author:

gkspencer

Constructor Summary

Constructors
Constructor and Description
`DERBuffer()` Default constructor
`DERBuffer(byte[] buf)` Create a data buffer to read data from
`DERBuffer(byte[] buf, int off, int len)` Create a data buffer to read data from
`DERBuffer(int siz)` Create a data buffer to write data to

Method Summary

Methods
Modifier and Type	Method and Description
`int`	`calculateLengthBytes(int len)` Calculate the number of length bytes required for a data length
`int`	`getAvailableLength()` Return the available data length
`byte[]`	`getBuffer()` Return the data buffer
`byte[]`	`getBytes()` Return the used buffer as a byte array
`int`	`getLength()` Return the data length
`int`	`getLengthInWords()` Return the data length in words
`int`	`getPosition()` Return the data position
`void`	`packApplicationSpecific(byte[] byts)` Pack an application specific object
`void`	`packApplicationSpecific(DERObject derObj)` Pack an application specific object
`void`	`packApplicationSpecific(int tagId, byte[] byts)` Pack an application specific object
`void`	`packApplicationSpecific(int tagId, DERObject derObj)` Pack an application specific object
`void`	`packApplicationSpecific(int tagId, List derList)` Pack an application specific list of objects
`void`	`packApplicationSpecific(List derList)` Pack an application specific list of objects
`void`	`packByte(int bval)` Append a byte value to the buffer
`void`	`packByteAt(int pos, int bval)` Pack a byte at the specified position
`void`	`packBytes(byte[] buf, int off, int len)` Pack bytes into the buffer
`void`	`packBytes(DERBuffer buf)` Pack bytes from the specified DER buffer into this buffer
`void`	`packInt(int ival)` Pack an integer value
`void`	`packLength(int len)` Pack a data length
`void`	`packLong(long lval)` Pack a long value
`void`	`packObject(DERObject derObj)` Pack an object
`int`	`peekType()` Peek at the next type in the buffer
`void`	`setEndOfBuffer()` Set the end of buffer position, and reset the read position to the beginning of the buffer
`void`	`setLength(int len)` Set the data length
`void`	`setPosition(int pos)` Set the read/write buffer position
`DERObject`	`unpackApplicationSpecific()` Unpack an application specific object
`byte[]`	`unpackApplicationSpecificBytes()` Unpack an application specific blob
`int`	`unpackByte()` Unpack a data byte from the buffer
`byte[]`	`unpackBytes(int len)` Unpack a block of bytes
`int`	`unpackInt(int len)` Unpack an integer value
`int`	`unpackLength()` Unpack a data length value
`long`	`unpackLong(int len)` Unpack a long (64 bit) value
`DERObject`	`unpackObject()` Unpack an object from the buffer
`int`	`unpackType()` Unpack a data type from the buffer

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

- Constructor Detail
  - DERBuffer
```
public DERBuffer()
```
    Default constructor
  - DERBuffer
```
public DERBuffer(int siz)
```
    Create a data buffer to write data to
    
    Parameters:
    siz - int
  - DERBuffer
```
public DERBuffer(byte[] buf,
         int off,
         int len)
```
    Create a data buffer to read data from
    
    Parameters:
    buf - byte[]
    off - int
    len - int
  - DERBuffer
```
public DERBuffer(byte[] buf)
```
    Create a data buffer to read data from
    
    Parameters:
    buf - byte[]
- Method Detail
  - getBuffer
```
public final byte[] getBuffer()
```
    Return the data buffer
    
    Returns:
    byte[]
  - getLength
```
public final int getLength()
```
    Return the data length
    
    Returns:
    int
  - getLengthInWords
```
public final int getLengthInWords()
```
    Return the data length in words
    
    Returns:
    int
  - getAvailableLength
```
public final int getAvailableLength()
```
    Return the available data length
    
    Returns:
    int
  - getPosition
```
public final int getPosition()
```
    Return the data position
    
    Returns:
    int
  - getBytes
```
public final byte[] getBytes()
```
    Return the used buffer as a byte array
    
    Returns:
    byte[]
  - unpackByte
```
public final int unpackByte()
```
    Unpack a data byte from the buffer
    
    Returns:
    int
  - unpackBytes
```
public final byte[] unpackBytes(int len)
```
    Unpack a block of bytes
    
    Parameters:
    len - int
    
    Returns:
    byte[]
  - peekType
```
public final int peekType()
```
    Peek at the next type in the buffer
    
    Returns:
    int
  - unpackType
```
public final int unpackType()
```
    Unpack a data type from the buffer
    
    Returns:
    int
  - unpackLength
```
public final int unpackLength()
```
    Unpack a data length value
    
    Returns:
    int
  - unpackObject
```
public final DERObject unpackObject()
                             throws IOException
```
    Unpack an object from the buffer
    
    Returns:
    DERObject
    
    Throws:
    
    IOException
  - unpackInt
```
public final int unpackInt(int len)
```
    Unpack an integer value
    
    Parameters:
    len - int
    
    Returns:
    int
  - unpackLong
```
public final long unpackLong(int len)
```
    Unpack a long (64 bit) value
    
    Parameters:
    len - int
    
    Returns:
    long
  - packByte
```
public final void packByte(int bval)
```
    Append a byte value to the buffer
    
    Parameters:
    bval - int
  - packByteAt
```
public final void packByteAt(int pos,
              int bval)
```
    Pack a byte at the specified position
    
    Parameters:
    pos - int
    bval - int
  - packBytes
```
public final void packBytes(byte[] buf,
             int off,
             int len)
```
    Pack bytes into the buffer
    
    Parameters:
    buf - byte[]
    off - int
    len - int
  - packBytes
```
public final void packBytes(DERBuffer buf)
```
    Pack bytes from the specified DER buffer into this buffer
    
    Parameters:
    buf - DERBuffer
  - packLength
```
public final void packLength(int len)
```
    Pack a data length
    
    Parameters:
    len - int
  - packInt
```
public final void packInt(int ival)
```
    Pack an integer value
    
    Parameters:
    ival - int
  - packLong
```
public final void packLong(long lval)
```
    Pack a long value
    
    Parameters:
    lval - long
  - packObject
```
public final void packObject(DERObject derObj)
                      throws IOException
```
    Pack an object
    
    Parameters:
    derObj - DERObject
    
    Throws:
    
    IOException
  - packApplicationSpecific
```
public final void packApplicationSpecific(DERObject derObj)
                                   throws IOException
```
    Pack an application specific object
    
    Parameters:
    derObj - DERObject
    
    Throws:
    
    IOException
  - packApplicationSpecific
```
public final void packApplicationSpecific(int tagId,
                           DERObject derObj)
                                   throws IOException
```
    Pack an application specific object
    
    Parameters:
    tagId - int
    derObj - DERObject
    
    Throws:
    
    IOException
  - packApplicationSpecific
```
public final void packApplicationSpecific(List derList)
                                   throws IOException
```
    Pack an application specific list of objects
    
    Parameters:
    derList - List
    
    Throws:
    
    IOException
  - packApplicationSpecific
```
public final void packApplicationSpecific(int tagId,
                           List derList)
                                   throws IOException
```
    Pack an application specific list of objects
    
    Parameters:
    tagId - int
    derList - List
    
    Throws:
    
    IOException
  - packApplicationSpecific
```
public final void packApplicationSpecific(int tagId,
                           byte[] byts)
                                   throws IOException
```
    Pack an application specific object
    
    Parameters:
    tagId - int
    byts - byte[]
    
    Throws:
    
    IOException
  - packApplicationSpecific
```
public final void packApplicationSpecific(byte[] byts)
                                   throws IOException
```
    Pack an application specific object
    
    Parameters:
    byts - byte[]
    
    Throws:
    
    IOException
  - unpackApplicationSpecific
```
public final DERObject unpackApplicationSpecific()
                                          throws IOException
```
    Unpack an application specific object
    
    Returns:
    DERObject
    
    Throws:
    
    IOException
  - unpackApplicationSpecificBytes
```
public final byte[] unpackApplicationSpecificBytes()
                                            throws IOException
```
    Unpack an application specific blob
    
    Returns:
    byte[]
    
    Throws:
    
    IOException
  - calculateLengthBytes
```
public final int calculateLengthBytes(int len)
```
    Calculate the number of length bytes required for a data length
    
    Parameters:
    len - int
    
    Returns:
    int
  - setPosition
```
public final void setPosition(int pos)
```
    Set the read/write buffer position
    
    Parameters:
    pos - int
  - setEndOfBuffer
```
public final void setEndOfBuffer()
```
    Set the end of buffer position, and reset the read position to the beginning of the buffer
  - setLength
```
public final void setLength(int len)
```
    Set the data length
    
    Parameters:
    len - int

Class DERBuffer

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

DERBuffer

DERBuffer

DERBuffer

DERBuffer

Method Detail

getBuffer

getLength

getLengthInWords

getAvailableLength

getPosition

getBytes

unpackByte

unpackBytes

peekType

unpackType

unpackLength

unpackObject

unpackInt

unpackLong

packByte

packByteAt

packBytes

packBytes

packLength

packInt

packLong

packObject

packApplicationSpecific

packApplicationSpecific

packApplicationSpecific

packApplicationSpecific

packApplicationSpecific

packApplicationSpecific

unpackApplicationSpecific

unpackApplicationSpecificBytes

calculateLengthBytes

setPosition

setEndOfBuffer

setLength