Kurt Nelson

UPDATED! See this post

Here is my java implementation of Steve Gibson’s PPPv2 built off of John Graham-Cumming’s Java Phone Client Implementation. My class will handle all of the necessary functions to create a PPP card including performing the SHA-256 hash of a passcode to the 64 character sequence key.

This is a copy of my example driver for my class:

 1: Scanner in = new Scanner(System.in);

 2: System.out.print("Password: ");

 3: String password = in.next();

 4: System.out.print("Card #: ");

 5: int card = in.nextInt();

 6: System.out.print("Column: ");

 7: String col = in.next();

 8: System.out.print("Row: ");

 9: int row = in.nextInt();

 10: String sequencekey = PPPengine.findSequenceKey(password);

 11: PPPengine card1 = new PPPengine(sequencekey);

 12: System.out.println("Your one-time code is "+card1.makePasscode (card,col,row));

<p>.csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, “Courier New”, courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }

Download the zip file including the source, the bytecode, the javadocs, a demonstration jar file, and a demonstration exe file made from the jar using jSmooth.

Class PPPengine Java Doc

java.lang.Object extended by PPPengine

public class PPPengine
extends java.lang.Object

Main class for PPP password calculations.

PPPengine

public PPPengine(java.lang.String sequencekey)

Initiates the PPP card object. Use this to create a virtual replacement for printed PPP cards. Takes sequence key only.

Parameters:

sequencekey – 64 Character key used to generate card

columnToInt

public int columnToInt(java.lang.String s)

Converts A-F to 0-6 for the PPPengine.

Parameters:

s – String A-F to be converted

Returns:

0-5 to be used as column

Throws:

java.lang.IllegalArgumentException

makePasscode

public java.lang.String makePasscode()

Generates the passcode using the Rinjndael cypher.

Returns:

String of 4 characters that is the passcode.

Throws:

java.lang.IllegalArgumentException

See Also:

Rinjndael

makePasscode

public java.lang.String makePasscode(int cardNumber, java.lang.String column, int row)

Generates and returns specified passcode. Takes String column.

Parameters:

cardNumber – Card number

column – String A-F specifing column

row – Int 1-10 specifing row

makePasscode

public java.lang.String makePasscode(int cardNumber, int column, int row)

Generates and returns specified passcode. Takes integer column.

Parameters:

cardNumber – Card number

column – Int 1-6 specifing column

row – Int 1-10 specifing row

findSequenceKey

public static java.lang.String findSequenceKey(java.lang.String passphrase)

Creates 64-bit sequence key from passphrase using SHA-256.

Parameters:

passphrase – String passphrase to be converted

Returns:

String 64-bit sequence key