Add publicKey property test

common/src/main/java/dev/openrs2/common/crypto/Rsa.kt

@@ -24,6 +24,9 @@ import java.math.BigInteger
 import java.nio.file.Files
 import java.nio.file.Path
 
+val RSAPrivateCrtKeyParameters.publicKey
+    get() = RSAKeyParameters(false, modulus, publicExponent)
+
 private fun ByteBuf.toBigInteger(): BigInteger {
     val bytes: ByteArray
     if (hasArray() && arrayOffset() == 0 && readerIndex() == 0 && readableBytes() == array().size) {
@@ -67,9 +70,6 @@ object Rsa {
     // 1 in 2^80
     private const val CERTAINTY = 80
 
-    val RSAPrivateCrtKeyParameters.publicKey
-        get() = RSAKeyParameters(false, modulus, publicExponent)
-
     fun generateKeyPair(): Pair<RSAKeyParameters, RSAPrivateCrtKeyParameters> {
         val generator = RSAKeyPairGenerator()
         generator.init(RSAKeyGenerationParameters(F4, secureRandom, KEY_LENGTH, CERTAINTY))

common/src/test/java/dev/openrs2/common/crypto/RsaTest.kt

@@ -178,6 +178,13 @@ object RsaTest {
         }
     }
 
+    @Test
+    fun testPrivateToPublicKey() {
+        val public = allowUnsafeMod { PRIVATE_KEY_CRT.publicKey }
+        assertEquals(PUBLIC_KEY.modulus, public.modulus)
+        assertEquals(PUBLIC_KEY.exponent, public.exponent)
+    }
+
     private fun <T> allowUnsafeMod(f: () -> T): T {
         Properties.setThreadOverride(ALLOW_UNSAFE_MOD, true)
         try {