Moved SecureStorage to util :truck:

1 files changed, 71 insertions, 0 deletions

diff --git a/app/src/main/java/me/texx/Texx/Util/SecureStorage.kt b/app/src/main/java/me/texx/Texx/Util/SecureStorage.kt
new file mode 100644
index 0000000..86b5cbf
--- /dev/null
+++ b/app/src/main/java/me/texx/Texx/Util/SecureStorage.kt
@@ -0,0 +1,71 @@
+package me.texx.Texx.Util
+
+import android.content.Context
+import android.preference.PreferenceManager
+import android.util.Base64
+import com.kazakago.cryptore.CipherAlgorithm
+import com.kazakago.cryptore.Cryptore
+import com.madapps.prefrences.EasyPrefrences
+
+/**
+ * Class for saving data securely in SharedPreferences
+ */
+class SecureStorage(private val context: Context) {
+    /**
+     * Encrypts and saves the [value] with [key] as index
+     */
+    fun set(key: String, value: String) {
+        sharedPrefs.putString(key, encryptAES(value))
+    }
+
+    /**
+     * Finds the encrypted value by [key], decrypts it and returns the value as string
+     */
+    fun get(key: String): String? {
+        return try {
+            decryptAES(sharedPrefs.getString(key))
+        } catch (e: Exception) {
+            null
+        }
+    }
+
+    private val sharedPrefs = EasyPrefrences(context)
+
+    private enum class Alias(val value: String) {
+        RSA("CIPHER_RSA"),
+        AES("CIPHER_AES")
+    }
+
+    private val cryptoreAES: Cryptore by lazy {
+        val builder = Cryptore.Builder(alias = Alias.AES.value, type = CipherAlgorithm.AES)
+        builder.build()
+    }
+
+    private fun encryptAES(plainStr: String): String {
+        val plainByte = plainStr.toByteArray()
+        val result = cryptoreAES.encrypt(plainByte = plainByte)
+        cipherIV = result.cipherIV
+        return Base64.encodeToString(result.bytes, Base64.DEFAULT)
+    }
+
+    private fun decryptAES(encryptedStr: String): String {
+        val encryptedByte = Base64.decode(encryptedStr, Base64.DEFAULT)
+        val result = cryptoreAES.decrypt(encryptedByte = encryptedByte, cipherIV = cipherIV)
+        return String(result.bytes)
+    }
+
+    private var cipherIV: ByteArray?
+        get() {
+            val preferences = PreferenceManager.getDefaultSharedPreferences(this.context)
+            preferences.getString("cipher_iv", null)?.let {
+                return Base64.decode(it, Base64.DEFAULT)
+            }
+            return null
+        }
+        set(value) {
+            val preferences = PreferenceManager.getDefaultSharedPreferences(this.context)
+            val editor = preferences.edit()
+            editor.putString("cipher_iv", Base64.encodeToString(value, Base64.DEFAULT))
+            editor.apply()
+        }
+}
\ No newline at end of file