Dropping AES gcm from public api as it's not portable in libsodium and going the xchacha20poly1305 as only AEAD

multiplatform-crypto-api/src/commonMain/kotlin/com/ionspin/kotlin/crypto/authenticated/Aes256Gcm.kt

@@ -6,10 +6,10 @@ package com.ionspin.kotlin.crypto.authenticated
  * on 14-Jun-2020
  */
 interface Aes256GcmStateless {
-    /**
-     * Nonce autogenerated, key autogenerated
-     */
-    fun encrypt(message: UByteArray, additionalData: UByteArray, rawData : UByteArray) : Aes256GcmEncryptionResult
+
+    fun encrypt(message: UByteArray, additionalData: UByteArray, rawData : UByteArray, key: Aes256GcmKey) : Aes256GcmEncryptionResult
+
+    fun decrypt(encryptedData: UByteArray, nonce: UByteArray, key : Aes256GcmKey) : UByteArray
 }
 
 data class Aes256GcmEncryptionResult(val cyphertext : UByteArray, val additionalData: UByteArray, val nonce: UByteArray, val tag: UByteArray) {
@@ -35,3 +35,8 @@ data class Aes256GcmEncryptionResult(val cyphertext : UByteArray, val additional
         return result
     }
 }
+
+
+interface Aes256GcmKey {
+    val key : UByteArray
+}

multiplatform-crypto-api/src/commonMain/kotlin/com/ionspin/kotlin/crypto/authenticated/XChaCha20Poly1305.kt

@@ -0,0 +1,8 @@
+package com.ionspin.kotlin.crypto.authenticated
+
+/**
+ * Created by Ugljesa Jovanovic
+ * ugljesa.jovanovic@ionspin.com
+ * on 14-Jun-2020
+ */
+interface XChaCha20Poly1305

multiplatform-crypto-api/src/commonMain/kotlin/com/ionspin/kotlin/crypto/symmetric/XChaCha20.kt

@@ -0,0 +1,47 @@
+package com.ionspin.kotlin.crypto.symmetric
+
+/**
+ * Created by Ugljesa Jovanovic
+ * ugljesa.jovanovic@ionspin.com
+ * on 14-Jun-2020
+ */
+interface XChaCha20 {
+    interface Nonce {
+        val content: UByteArray
+    }
+
+    interface Key {
+        val content : UByteArray
+    }
+    fun encrypt(key: Key, inputMessage: UByteArray) : XChaCha20EncryptionResult
+
+    fun decrypt(key: Key, nonce: Nonce) : UByteArray
+}
+
+data class XChaCha20EncryptionResult(val nonce: UByteArray, val encryptionData: UByteArray) {
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (other == null || this::class != other::class) return false
+
+        other as XChaCha20EncryptionResult
+
+        if (nonce != other.nonce) return false
+        if (encryptionData != other.encryptionData) return false
+
+        return true
+    }
+
+    override fun hashCode(): Int {
+        var result = nonce.hashCode()
+        result = 31 * result + encryptionData.hashCode()
+        return result
+    }
+}
+
+
+
+interface XChaCha20KeyProvider {
+    fun generateNewKey() : XChaCha20.Key
+
+    fun createFromUByteArray(uByteArray: UByteArray) : XChaCha20.Key
+}