Security Code Snippets

• Create KeyStoreinstance and prepare it for working using AndroidKeyStore provider:

val keyStore = KeyStore.getInstance("AndroidKeyStore")
keyStore.load(null)

• Get information about keys currently existed in keystore:

// Define data class to store key info
data class KeyData(val alias: String, val creationDate: Date)
val keyData = keyStore.aliases().toList().map { KeyData(it, keyStore.getCreationDate(it)) }

• Prepare KeyGenerator instance for generating and saving AES symmetric keys using AndroidKeyStore provider:

val generator = KeyGenerator.getInstance(algorithm, "AndroidKeyStore")


val builder = KeyGenParameterSpec.Builder(alias, KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT)
                .setBlockModes(KeyProperties.BLOCK_MODE_CBC)
                .setUserAuthenticationRequired(userAuthenticationRequired)
                .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_PKCS7)
                .setInvalidatedByBiometricEnrollment(invalidatedByBiometricEnrollment)

generator?.init(builder.build())

// This will create and save key to KeyStore
val key = keyGenerator?.generateKey()

• Prepare KeyPairGenerator instance for generating and saving RSA asymmetric key pairs using AndroidKeyStore provider:

val generator = KeyPairGenerator.getInstance(keyProps.mKeyType, provider);

val startDate = Calendar.getInstance()
val endDate = Calendar.getInstance()
endDate.add(Calendar.YEAR, 20)

val builder = KeyGenParameterSpec.Builder(alias, KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT)
                .setCertificateSerialNumber(BigInteger.ONE)
                .setCertificateSubject(X500Principal("CN=${alias} CA Certificate"))
                .setCertificateNotBefore(startDate.time)
                .setCertificateNotAfter(endDate.time)
                .setBlockModes(KeyProperties.BLOCK_MODE_ECB)
                .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_RSA_PKCS1)

generator.initialize(generator.build())

// This will create and save key to KeyStore
val keyPair = generator?.generateKeyPair()