KeyPairGeneratorSpec.Builder Sınıfı

build metodu
Şöyle yaparız.

KeyPairGeneratorSpec.Builder keySpecBuilder = new KeyPairGeneratorSpec.Builder(context)
    .setAlias(keyName)
    .setSubject(new X500Principal("CN=" + keyName))
    .setSerialNumber(BigInteger.TEN)
    .setStartDate(start.getTime())
    .setEndDate(end.getTime())
    .setKeySize(RSA_KEY_SIZE);

KeyPairGeneratorSpec spec = keySpecBuilder.build();
KeyPairGenerator gen = KeyPairGenerator.getInstance("RSA", "AndroidKeyStore");
gen.initialize(spec);
gen.generateKeyPair();