Return RSAPrivateCrtKeyParameters from readPrivateKey

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

@@ -145,7 +145,7 @@ object Rsa {
         return writeSinglePemObject(path, PUBLIC_KEY, spki.encoded)
     }
 
-    fun readPrivateKey(path: Path): RSAKeyParameters {
+    fun readPrivateKey(path: Path): RSAPrivateCrtKeyParameters {
         val der = readSinglePemObject(path, PRIVATE_KEY)
 
         val pki = PrivateKeyInfo.getInstance(der)

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

@@ -150,7 +150,7 @@ object RsaTest {
             try {
                 Files.write(file, PRIVATE_KEY_PEM)
 
-                val key = allowUnsafeMod { Rsa.readPrivateKey(file) } as RSAPrivateCrtKeyParameters
+                val key = allowUnsafeMod { Rsa.readPrivateKey(file) }
                 assertTrue(key.isPrivate)
                 assertEquals(PRIVATE_KEY_CRT.modulus, key.modulus)
                 assertEquals(PRIVATE_KEY_CRT.exponent, key.exponent)