Add Amount class with tests

1 files changed, 21 insertions, 9 deletions

diff --git a/src/commonMain/kotlin/net/taler/wallet/kotlin/crypto/CryptoImpl.kt b/src/commonMain/kotlin/net/taler/wallet/kotlin/crypto/CryptoImpl.kt
index 98ee656..e6995b1 100644
--- a/src/commonMain/kotlin/net/taler/wallet/kotlin/crypto/CryptoImpl.kt
+++ b/src/commonMain/kotlin/net/taler/wallet/kotlin/crypto/CryptoImpl.kt
@@ -1,7 +1,28 @@
 package net.taler.wallet.kotlin.crypto
 
+import net.taler.wallet.kotlin.crypto.CryptoImpl.Companion.toByteArray
+
 abstract class CryptoImpl : Crypto {
 
+    companion object {
+        fun Int.toByteArray(): ByteArray {
+            val bytes = ByteArray(4)
+            bytes[3] = (this and 0xFFFF).toByte()
+            bytes[2] = ((this ushr 8) and 0xFFFF).toByte()
+            bytes[1] = ((this ushr 16) and 0xFFFF).toByte()
+            bytes[0] = ((this ushr 24) and 0xFFFF).toByte()
+            return bytes
+        }
+
+        fun Long.toByteArray() = ByteArray(8).apply {
+            var l = this@toByteArray
+            for (i in 7 downTo 0) {
+                this[i] = (l and 0xFF).toByte()
+                l = l shr 8
+            }
+        }
+    }
+
     override fun kdf(outputLength: Int, ikm: ByteArray, salt: ByteArray, info: ByteArray): ByteArray {
         return Kdf.kdf(outputLength, ikm, salt, info, { sha256(it) }, { sha512(it) })
     }
@@ -15,13 +36,4 @@ abstract class CryptoImpl : Crypto {
         return FreshCoin(eddsaGetPublic(coinPrivateKey), coinPrivateKey, bks)
     }
 
-    private fun Int.toByteArray(): ByteArray {
-        val bytes = ByteArray(4)
-        bytes[3] = (this and 0xFFFF).toByte()
-        bytes[2] = ((this ushr 8) and 0xFFFF).toByte()
-        bytes[1] = ((this ushr 16) and 0xFFFF).toByte()
-        bytes[0] = ((this ushr 24) and 0xFFFF).toByte()
-        return bytes
-    }
-
 }