cleanup rsa encryption

This commit is contained in:
Kyle Spearrin 2017-06-05 22:25:59 -04:00
parent 93176989fd
commit cf079a159f
1 changed files with 25 additions and 45 deletions

View File

@ -10,7 +10,6 @@ using Java.Math;
using Android.Security.Keystore;
using Android.App;
using Plugin.Settings.Abstractions;
using System.Collections.Generic;
using Java.Util;
namespace Bit.Android.Services
@ -18,19 +17,21 @@ namespace Bit.Android.Services
public class KeyStoreBackedStorageService : ISecureStorageService
{
private const string AndroidKeyStore = "AndroidKeyStore";
private const string AndroidOpenSSL = "AndroidOpenSSL";
private const string KeyAlias = "bitwardenKey";
private const string SettingsFormat = "ksSecured:{0}";
private const string RsaMode = "RSA/ECB/PKCS1Padding";
private const string AesKey = "ksSecured:aesKeyForService";
private readonly string _rsaMode;
private readonly bool _oldAndroid;
private readonly ISettings _settings;
private readonly KeyStore _keyStore;
private readonly bool _oldAndroid = Build.VERSION.SdkInt < BuildVersionCodes.M;
private readonly ISecureStorageService _oldKeyStorageService;
public KeyStoreBackedStorageService(ISettings settings)
{
_oldAndroid = Build.VERSION.SdkInt < BuildVersionCodes.M;
_rsaMode = _oldAndroid ? "RSA/ECB/PKCS1Padding" : "RSA/ECB/OAEPWithSHA-256AndMGF1Padding";
_oldKeyStorageService = new KeyStoreStorageService(new char[] { });
_settings = settings;
@ -118,6 +119,7 @@ namespace Bit.Android.Services
return;
}
var gen = KeyPairGenerator.GetInstance(KeyProperties.KeyAlgorithmRsa, AndroidKeyStore);
var start = Calendar.Instance;
var end = Calendar.Instance;
end.Add(CalendarField.Year, 30);
@ -125,7 +127,6 @@ namespace Bit.Android.Services
if(_oldAndroid)
{
var gen = KeyPairGenerator.GetInstance(KeyProperties.KeyAlgorithmRsa, AndroidKeyStore);
var spec = new KeyPairGeneratorSpec.Builder(Application.Context)
.SetAlias(KeyAlias)
.SetSubject(subject)
@ -135,21 +136,22 @@ namespace Bit.Android.Services
.Build();
gen.Initialize(spec);
gen.GenerateKeyPair();
}
else
{
var gen = KeyGenerator.GetInstance(KeyProperties.KeyAlgorithmRsa, AndroidKeyStore);
var spec = new KeyGenParameterSpec.Builder(KeyAlias, KeyStorePurpose.Decrypt | KeyStorePurpose.Encrypt)
.SetCertificateSubject(subject)
.SetCertificateSerialNumber(BigInteger.Ten)
.SetKeyValidityStart(start.Time)
.SetKeyValidityEnd(end.Time)
.SetDigests(KeyProperties.DigestSha256)
.SetEncryptionPaddings(KeyProperties.EncryptionPaddingRsaOaep)
.Build();
gen.Init(spec);
gen.GenerateKey();
gen.Initialize(spec);
}
gen.GenerateKeyPair();
}
private KeyStore.PrivateKeyEntry GetRsaKeyEntry()
@ -192,48 +194,26 @@ namespace Bit.Android.Services
}
}
private byte[] RsaEncrypt(byte[] input)
private byte[] RsaEncrypt(byte[] data)
{
var entry = GetRsaKeyEntry();
var inputCipher = Cipher.GetInstance(RsaMode, AndroidOpenSSL);
inputCipher.Init(CipherMode.EncryptMode, entry.Certificate.PublicKey);
var outputStream = new MemoryStream();
var cipherStream = new CipherOutputStream(outputStream, inputCipher);
cipherStream.Write(input);
cipherStream.Close();
var vals = outputStream.ToArray();
outputStream.Close();
return vals;
using(var entry = GetRsaKeyEntry())
using(var cipher = Cipher.GetInstance(_rsaMode))
{
cipher.Init(CipherMode.EncryptMode, entry.Certificate.PublicKey);
var cipherText = cipher.DoFinal(data);
return cipherText;
}
}
private byte[] RsaDecrypt(byte[] encInput)
private byte[] RsaDecrypt(byte[] encData)
{
var entry = GetRsaKeyEntry();
var outputCipher = Cipher.GetInstance(RsaMode, AndroidOpenSSL);
outputCipher.Init(CipherMode.DecryptMode, entry.PrivateKey);
var inputStream = new MemoryStream(encInput);
var cipherStream = new CipherInputStream(inputStream, outputCipher);
var values = new List<byte>();
int nextByte;
while((nextByte = cipherStream.Read()) != -1)
using(var entry = GetRsaKeyEntry())
using(var cipher = Cipher.GetInstance(_rsaMode))
{
values.Add((byte)nextByte);
cipher.Init(CipherMode.DecryptMode, entry.PrivateKey);
var plainText = cipher.DoFinal(encData);
return plainText;
}
inputStream.Close();
cipherStream.Close();
var bytes = new byte[values.Count];
for(var i = 0; i < bytes.Length; i++)
{
bytes[i] = values[i];
}
return bytes;
}
private byte[] TryGetAndMigrateFromOldKeyStore(string key)