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gnu.crypto.sasl.srp
Class SRP

java.lang.Object
  extended bygnu.crypto.sasl.srp.SRP

public final class SRP
extends Object

A Factory class that returns SRP Singletons that know all SRP-related mathematical computations and protocol-related operations for both the client- and server-sides.

Version:
$Revision: 1.6 $

Method Summary
 byte[] computeX(byte[] s, String user, byte[] p)
           
 byte[] computeX(byte[] s, String user, String password)
           
 byte[] digest(byte[] src)
          Convenience method to return the result of digesting the designated input with a new instance of the SRP message digest algorithm.
 byte[] digest(String src)
          Convenience method to return the result of digesting the designated input with a new instance of the SRP message digest algorithm.
 byte[] generateKn(byte[] K, byte[] cn, byte[] sn)
           
 byte[] generateM1(BigInteger N, BigInteger g, String U, byte[] s, BigInteger A, BigInteger B, byte[] K, String I, String L, byte[] cn, byte[] cCB)
           
 byte[] generateM2(BigInteger A, byte[] M1, byte[] K, String U, String I, String o, byte[] sid, int ttl, byte[] cIV, byte[] sIV, byte[] sCB)
           
 String getAlgorithm()
           
static SRP instance(String mdName)
          Returns an instance of this object that uses the designated message digest algorithm as its digest function.
 IMessageDigest newDigest()
          Returns a new instance of the SRP message digest algorithm --which is SHA-160 by default, but could be anything else provided the proper conditions as specified in the SRP specifications.
 byte[] xor(byte[] a, byte[] b)
          Convenience method to XOR N bytes from two arrays; N being the output size of the SRP message digest algorithm.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

instance

public static SRP instance(String mdName)

Returns an instance of this object that uses the designated message digest algorithm as its digest function.

Returns:
an instance of this object for the designated digest name.

getAlgorithm

public String getAlgorithm()
Returns:
the message digest algorithm name used by this instance.

newDigest

public IMessageDigest newDigest()

Returns a new instance of the SRP message digest algorithm --which is SHA-160 by default, but could be anything else provided the proper conditions as specified in the SRP specifications.

Returns:
a new instance of the underlying SRP message digest algorithm.
Throws:
RuntimeException - if the implementation of the message digest algorithm does not support cloning.

digest

public byte[] digest(byte[] src)

Convenience method to return the result of digesting the designated input with a new instance of the SRP message digest algorithm.

Parameters:
src - some bytes to digest.
Returns:
the bytes constituting the result of digesting the designated input with a new instance of the SRP message digest algorithm.

digest

public byte[] digest(String src)
              throws UnsupportedEncodingException

Convenience method to return the result of digesting the designated input with a new instance of the SRP message digest algorithm.

Parameters:
src - a String whose bytes (using US-ASCII encoding) are to be digested.
Returns:
the bytes constituting the result of digesting the designated input with a new instance of the SRP message digest algorithm.
Throws:
UnsupportedEncodingException - if US-ASCII charset is not found.

xor

public byte[] xor(byte[] a,
                  byte[] b)

Convenience method to XOR N bytes from two arrays; N being the output size of the SRP message digest algorithm.

Parameters:
a - the first byte array.
b - the second one.
Returns:
N bytes which are the result of the XOR operations on the first N bytes from the designated arrays. N is the size of the SRP message digest algorithm; eg. 20 for SHA-160.

generateM1

public byte[] generateM1(BigInteger N,
                         BigInteger g,
                         String U,
                         byte[] s,
                         BigInteger A,
                         BigInteger B,
                         byte[] K,
                         String I,
                         String L,
                         byte[] cn,
                         byte[] cCB)
                  throws UnsupportedEncodingException
Throws:
UnsupportedEncodingException

generateM2

public byte[] generateM2(BigInteger A,
                         byte[] M1,
                         byte[] K,
                         String U,
                         String I,
                         String o,
                         byte[] sid,
                         int ttl,
                         byte[] cIV,
                         byte[] sIV,
                         byte[] sCB)
                  throws UnsupportedEncodingException
Throws:
UnsupportedEncodingException

generateKn

public byte[] generateKn(byte[] K,
                         byte[] cn,
                         byte[] sn)

computeX

public byte[] computeX(byte[] s,
                       String user,
                       String password)
                throws UnsupportedEncodingException
Throws:
UnsupportedEncodingException

computeX

public byte[] computeX(byte[] s,
                       String user,
                       byte[] p)
                throws UnsupportedEncodingException
Throws:
UnsupportedEncodingException

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