org.bouncycastle.crypto.test
Class ConstantTimeUsageTest

java.lang.Object
  org.bouncycastle.util.test.SimpleTest
      org.bouncycastle.crypto.test.ConstantTimeUsageTest

All Implemented Interfaces:

Test

public class ConstantTimeUsageTest

extends SimpleTest

Checks that the code paths handling a secret scalar still reach for BouncyCastle's hardened arithmetic rather than the variable-time defaults.

The substitutions guarded here - BigInteger.modInverse to BigIntegers.modOddInverse, add([]).mod([]) to BigIntegers.modAdd, and the default point multiplier to the secure one - all preserve the result, so no functional test can tell whether they are in place: the KAT vectors and the round-trips pass either way, which is exactly why the substitutions can be undone by an unrelated edit without anything going red. What is left to look at is the compiled form, so this test reads each class file back and checks the symbols its constant pool must and must not contain.

Note what this does and does not establish. It says a named call is still being made; it says nothing about whether the surrounding code is constant time, and it cannot see a secret that reaches a variable-time operation by some other route. It is a regression gate for four specific call sites, not a proof.

A scan that quietly reads nothing would pass every "must not contain" check, so the controls in #checkControls() are load bearing: they run the same scan over a class in this file that deliberately calls BigInteger.modInverse, and fail if it is not flagged.

Nested Class Summary

Nested classes inherited from class org.bouncycastle.util.test.SimpleTest

SimpleTest.TestExceptionOperation

Constructor Summary

ConstantTimeUsageTest()

Method Summary

java.lang.String	getName()
static void	main(java.lang.String[] args)
void	performTest()

Methods inherited from class org.bouncycastle.util.test.SimpleTest

areEqual, areEqual, areEqual, fail, fail, fail, isEquals, isEquals, isEquals, isEquals, isEquals, isEquals, isEquals, isTrue, isTrue, perform, runTest, runTest, runTests, runTests, testException

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ConstantTimeUsageTest

public ConstantTimeUsageTest()

Method Detail

getName

public java.lang.String getName()

Specified by:

getName in interface Test

Specified by:

getName in class SimpleTest

performTest

public void performTest()
                 throws java.lang.Exception

Specified by:

performTest in class SimpleTest

Throws:

java.lang.Exception

main

public static void main(java.lang.String[] args)