Started working on sodium_ utility functions

multiplatform-crypto-libsodium-bindings/src/commonMain/kotlin/com.ionspin.kotlin.crypto/util/LibsodiumUtil.kt

@@ -5,6 +5,19 @@ package com.ionspin.kotlin.crypto.util
  * ugljesa.jovanovic@ionspin.com
  * on 31-Aug-2020
  */
-//expect object LibsodiumUtil {
-//
-//}
+expect object LibsodiumUtil {
+
+    fun memcmp(first: UByteArray, second: UByteArray) : Boolean
+    fun memzero(target: UByteArray)
+
+    fun pad(unpaddedData : UByteArray, blocksize: Int) : UByteArray
+    fun unpad(paddedData: UByteArray, blocksize: Int) : UByteArray
+
+    fun toBase64(data: UByteArray) : String
+    fun toHex(data: UByteArray) : String
+    fun toString(data : UByteArray) : String
+
+    fun fromBase64(data: String) : UByteArray
+    fun fromHex(data: String) : UByteArray
+    fun fromString(data: String) : UByteArray
+}

multiplatform-crypto-libsodium-bindings/src/commonTest/kotlin/com/ionspin/kotlin/crypto/util/LibsodiumUtilTest.kt

@@ -0,0 +1,27 @@
+package com.ionspin.kotlin.crypto.util
+
+import com.ionspin.kotlin.bignum.integer.util.hexColumsPrint
+import kotlin.test.Test
+import kotlin.test.assertTrue
+
+/**
+ * Created by Ugljesa Jovanovic
+ * ugljesa.jovanovic@ionspin.com
+ * on 25-Sep-2020
+ */
+
+class LibsodiumUtilTest {
+    @Test
+    fun testPadding() {
+        val input = ubyteArrayOf(1U, 2U)
+        val blocksize = 16
+        val padded = LibsodiumUtil.pad(input, blocksize)
+        println(padded.hexColumsPrint())
+        val unpadded = LibsodiumUtil.unpad(padded, blocksize)
+        println(unpadded.hexColumsPrint())
+
+        assertTrue {
+            input.contentEquals(unpadded)
+        }
+    }
+}

multiplatform-crypto-libsodium-bindings/src/nativeMain/kotlin/com/ionspin/kotlin/crypto/util/LibsodiumUtil.kt

@@ -0,0 +1,102 @@
+package com.ionspin.kotlin.crypto.util
+
+import kotlinx.cinterop.StableRef
+import kotlinx.cinterop.addressOf
+import kotlinx.cinterop.convert
+import kotlinx.cinterop.pin
+import kotlinx.cinterop.reinterpret
+import libsodium.sodium_memcmp
+import libsodium.sodium_memzero
+import libsodium.sodium_pad
+import libsodium.sodium_unpad
+import platform.posix.size_t
+
+/**
+ * Created by Ugljesa Jovanovic
+ * ugljesa.jovanovic@ionspin.com
+ * on 31-Aug-2020
+ */
+actual object LibsodiumUtil {
+
+
+    actual fun memcmp(first: UByteArray, second: UByteArray): Boolean {
+        val firstPinned = first.pin()
+        val secondPinned = second.pin()
+        val result = sodium_memcmp(firstPinned.toPtr(), secondPinned.toPtr(), first.size.convert())
+        firstPinned.unpin()
+        secondPinned.unpin()
+        return result == 0
+    }
+
+    actual fun memzero(target: UByteArray) {
+        val targetPinned = target.pin()
+        sodium_memzero(targetPinned.toPtr(), target.size.convert())
+    }
+
+    actual fun pad(unpaddedData : UByteArray, blocksize: Int) : UByteArray {
+        val resultingSize = if (unpaddedData.size % blocksize != 0 ) {
+            ((unpaddedData.size / blocksize) + 1 ) * blocksize
+        } else {
+            unpaddedData.size + 1
+        }
+        val paddedData = UByteArray(resultingSize)
+        unpaddedData.copyInto(paddedData, 0, 0)
+        val paddedDataPinned = paddedData.pin()
+
+        sodium_pad(
+            null,
+            paddedDataPinned.toPtr(),
+            unpaddedData.size.convert(),
+            blocksize.convert(),
+            resultingSize.convert()
+        )
+        paddedDataPinned.unpin()
+        return paddedData
+    }
+
+    actual fun unpad(paddedData: UByteArray, blocksize: Int) : UByteArray {
+        val paddedDataCopy = paddedData.copyOf()
+        val paddedDataCopyPinned = paddedDataCopy.pin()
+        var newSize = ULongArray(1) { 99UL }
+        val newSizePinned = newSize.pin()
+        sodium_unpad(
+            newSizePinned.addressOf(0),
+            paddedDataCopyPinned.toPtr(),
+            paddedData.size.convert(),
+            blocksize.convert()
+        )
+        val unpaddedSize = newSize[0]
+        if (unpaddedSize > Int.MAX_VALUE.toULong()) {
+            throw RuntimeException("Unsupported array size (larger than Integer max value) $unpaddedSize")
+        }
+        val unpadded = paddedDataCopy.sliceArray(0 until unpaddedSize.toInt())
+        paddedDataCopyPinned.unpin()
+        newSizePinned.unpin()
+        return unpadded
+    }
+
+    actual fun toBase64(data: UByteArray): String {
+        TODO("not implemented yet")
+    }
+
+    actual fun toHex(data: UByteArray): String {
+        TODO("not implemented yet")
+    }
+
+    actual fun toString(data: UByteArray): String {
+        TODO("not implemented yet")
+    }
+
+    actual fun fromBase64(data: String): UByteArray {
+        TODO("not implemented yet")
+    }
+
+    actual fun fromHex(data: String): UByteArray {
+        TODO("not implemented yet")
+    }
+
+    actual fun fromString(data: String): UByteArray {
+        TODO("not implemented yet")
+    }
+
+}