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/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
*/
package mozilla.lockbox.support
import android.content.Context
import android.content.SharedPreferences
import android.util.Base64
import androidx.preference.PreferenceManager
import mozilla.components.lib.dataprotect.Keystore
import mozilla.lockbox.log
import mozilla.lockbox.store.ContextStore
import java.nio.charset.StandardCharsets
import java.security.GeneralSecurityException
private const val BASE_64_FLAGS = Base64.URL_SAFE or Base64.NO_PADDING
open class SecurePreferences(
private val keystore: Keystore = Keystore(Constant.App.keystoreLabel)
) : ContextStore {
companion object {
val shared by lazy { SecurePreferences() }
}
private lateinit var prefs: SharedPreferences
override fun injectContext(context: Context) {
prefs = PreferenceManager.getDefaultSharedPreferences(context)
}
open fun getString(key: String): String? {
verifyKey()
return if (prefs.contains(key)) {
val value = prefs.getString(key, "")
val encrypted = Base64.decode(value, BASE_64_FLAGS)
val plain = try {
keystore.decryptBytes(encrypted)
} catch (error: IllegalArgumentException) {
log.error("IllegalArgumentException exception: ", error)
null
} catch (error: GeneralSecurityException) {
log.error("Decrypt exception: ", error)
null
}
plain.let {
if (it != null) String(it, StandardCharsets.UTF_8) else null
}
} else {
null
}
}
open fun putString(key: String, value: String) {
verifyKey()
val editor = prefs.edit()
val encrypted = keystore.encryptBytes(value.toByteArray(StandardCharsets.UTF_8))
val data = Base64.encodeToString(encrypted, BASE_64_FLAGS)
editor.putString(key, data).apply()
}
open fun remove(key: String) {
val editor = prefs.edit()
editor.remove(key)
editor.apply()
}
open fun clear() = prefs
.edit()
.clear()
.apply()
// these methods won't be used until https://github.com/mozilla-lockwise/lockwise-android/issues/165
// is addressed.
// open fun createEncryptCipher(): Cipher {
// verifyKey()
//
// return keystore.createEncryptCipher()
// }
//
// open fun createDecryptCipher(byteArray: ByteArray): Cipher {
// verifyKey()
//
// return keystore.createDecryptCipher(byteArray)
// }
private fun verifyKey() {
if (!keystore.available()) {
keystore.generateKey()
}
}
}