Files
coop-mobile/composeApp/src/androidMain/kotlin/su/reya/coop/AppStorage.kt
2026-07-09 07:53:22 +00:00

115 lines
4.0 KiB
Kotlin

package su.reya.coop
import android.content.Context
import android.security.keystore.KeyGenParameterSpec
import android.security.keystore.KeyProperties
import android.util.Base64
import androidx.datastore.preferences.core.edit
import androidx.datastore.preferences.core.stringPreferencesKey
import androidx.datastore.preferences.preferencesDataStore
import kotlinx.coroutines.flow.first
import java.nio.charset.StandardCharsets
import java.security.KeyStore
import javax.crypto.Cipher
import javax.crypto.KeyGenerator
import javax.crypto.SecretKey
import javax.crypto.spec.GCMParameterSpec
private val Context.dataStore by preferencesDataStore("secret_store")
data class SecretEntry(val encrypted: String, val iv: String)
class SecretCrypto {
private val keyAlias = "coop"
private val keyStoreType = "AndroidKeyStore"
private val transformation = "AES/GCM/NoPadding"
fun encrypt(content: String): SecretEntry {
val cipher = Cipher.getInstance(transformation)
cipher.init(Cipher.ENCRYPT_MODE, getOrCreateKey())
val encrypted = cipher.doFinal(content.toByteArray())
val iv = cipher.iv
return SecretEntry(
encrypted = Base64.encodeToString(encrypted, Base64.NO_WRAP),
iv = Base64.encodeToString(iv, Base64.NO_WRAP)
)
}
fun decrypt(entry: SecretEntry): String {
val encrypted = Base64.decode(entry.encrypted, Base64.NO_WRAP)
val iv = Base64.decode(entry.iv, Base64.NO_WRAP)
val cipher = Cipher.getInstance(transformation)
val spec = GCMParameterSpec(128, iv)
cipher.init(Cipher.DECRYPT_MODE, getOrCreateKey(), spec)
val plaintext = cipher.doFinal(encrypted)
return String(plaintext, StandardCharsets.UTF_8)
}
private fun getOrCreateKey(): SecretKey {
val keyStore = KeyStore.getInstance(keyStoreType).apply { load(null) }
val existingKey = keyStore.getKey(keyAlias, null)
if (existingKey is SecretKey) return existingKey
val keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, keyStoreType)
val spec = KeyGenParameterSpec.Builder(
keyAlias,
KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT
)
.setBlockModes(KeyProperties.BLOCK_MODE_GCM)
.setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE)
.setKeySize(256)
.build()
keyGenerator.init(spec)
return keyGenerator.generateKey()
}
}
class AppStore(private val context: Context) : AppStorage {
private val crypto = SecretCrypto()
override suspend fun get(key: String): String? {
return context.dataStore.data.first()[stringPreferencesKey(key)]
}
override suspend fun set(key: String, value: String) {
context.dataStore.edit { it[stringPreferencesKey(key)] = value }
}
override suspend fun getSecret(key: String): String? {
val prefs = context.dataStore.data.first()
val encrypted = prefs[stringPreferencesKey("${key}_encrypted")] ?: return null
val iv = prefs[stringPreferencesKey("${key}_iv")] ?: return null
return crypto.decrypt(SecretEntry(encrypted, iv))
}
override suspend fun setSecret(key: String, value: String) {
val entry = crypto.encrypt(value)
context.dataStore.edit { prefs ->
prefs[stringPreferencesKey("${key}_encrypted")] = entry.encrypted
prefs[stringPreferencesKey("${key}_iv")] = entry.iv
}
}
override suspend fun clear(key: String) {
context.dataStore.edit { prefs ->
prefs.remove(stringPreferencesKey(key))
prefs.remove(stringPreferencesKey("${key}_encrypted"))
prefs.remove(stringPreferencesKey("${key}_iv"))
}
}
override suspend fun has(key: String): Boolean {
val prefs = context.dataStore.data.first()
return prefs.contains(stringPreferencesKey(key)) ||
prefs.contains(stringPreferencesKey("${key}_encrypted"))
}
}