Software BigNumberMath Library Package (Stub)

This is a JavaCard library package that provides a stub implementation of big number modular arithmetic operations.

Package AID

0xA0:0x00:0x00:0x08:0x04:0x00:0x02

Package Name

im.status.keycard.math

Version

1.0

Class

BigNumberMath - Stub implementation that throws exceptions for all operations

Methods

• modAdd(byte[] a, short aOff, short aLen, byte[] b, short bOff, short bLen, byte[] n, short nOff, short nLen) - Modular addition: a = (a + b) mod n - Implemented
• modMul(byte[] a, short aOff, short aLen, byte[] b, short bOff, short bLen, byte[] n, short nOff, short nLen) - Modular multiplication: a = (a * b) mod n - Throws ISOException
• modSub(byte[] a, short aOff, short aLen, byte[] b, short bOff, short bLen, byte[] n, short nOff, short nLen) - Modular subtraction: a = (a - b) mod n - Implemented
• modRed(byte[] a, short aOff, short aLen, byte[] n, short nOff, short nLen) - Modular reduction: a = a mod n - Throws ISOException

Building

./gradlew build

Dependencies

• None (pure JavaCard API)

Usage

This library package provides a software implementation for modular arithmetic. Just load it before Keycard's main package