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use aes key in keystore on "new" android. migrate.

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This commit is contained in:
Kyle Spearrin 2017-06-10 22:18:34 -04:00
parent 6a88524f8e
commit 6aaa083157
2 changed files with 108 additions and 50 deletions
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15
src/Android/MainApplication.cs
View file

@ -207,23 +207,10 @@ namespace Bit.Android
container.RegisterSingleton(application.ApplicationContext);
container.RegisterSingleton<Application>(application);
// Secure Storage
ISecureStorageService secureStorage;
try
{
secureStorage = new AndroidKeyStoreStorageService(CrossSettings.Current);
}
catch
{
// Some isolated devices are having a hard time generating RSA keys for the key store.
// Continue using the "old" keystore implementation for now.
secureStorage = new KeyStoreStorageService(new char[] { });
}
// Services
container.RegisterSingleton<IDatabaseService, DatabaseService>();
container.RegisterSingleton<ISqlService, SqlService>();
container.RegisterSingleton(secureStorage);
container.RegisterSingleton<ISecureStorageService, AndroidKeyStoreStorageService>();
container.RegisterSingleton<ICryptoService, CryptoService>();
container.RegisterSingleton<IKeyDerivationService, BouncyCastleKeyDerivationService>();
container.RegisterSingleton<IAuthService, AuthService>();

141
src/Android/Services/AndroidKeyStoreStorageService.cs
View file

@ -18,9 +18,16 @@ namespace Bit.Android.Services
public class AndroidKeyStoreStorageService : ISecureStorageService
{
private const string AndroidKeyStore = "AndroidKeyStore";
private const string KeyAlias = "bitwardenKey";
private const string SettingsFormat = "ksSecured:{0}";
private const string AesKey = "ksSecured:aesKeyForService";
private const string AesMode = "AES/GCM/NoPadding";
private const string KeyAlias = "bitwardenKey2";
private const string KeyAliasV1 = "bitwardenKey";
private const string SettingsFormat = "ksSecured2:{0}";
private const string SettingsFormatV1 = "ksSecured:{0}";
private const string AesKey = "ksSecured2:aesKeyForService";
private const string AesKeyV1 = "ksSecured:aesKeyForService";
private readonly string _rsaMode;
private readonly bool _oldAndroid;
@ -39,19 +46,26 @@ namespace Bit.Android.Services
_keyStore = KeyStore.GetInstance(AndroidKeyStore);
_keyStore.Load(null);
GenerateRsaKey();
GenerateStoreKey();
GenerateAesKey();
}
public bool Contains(string key)
{
return _settings.Contains(string.Format(SettingsFormat, key)) || _oldKeyStorageService.Contains(key);
return _settings.Contains(string.Format(SettingsFormat, key)) ||
_settings.Contains(string.Format(SettingsFormatV1, key)) ||
_oldKeyStorageService.Contains(key);
}
public void Delete(string key)
{
CleanupOldKeyStore(key);
_settings.Remove(string.Format(SettingsFormat, key));
CleanupOld(key);
var formattedKey = string.Format(SettingsFormat, key);
if(_settings.Contains(formattedKey))
{
_settings.Remove(formattedKey);
}
}
public byte[] Retrieve(string key)
@ -59,7 +73,7 @@ namespace Bit.Android.Services
var formattedKey = string.Format(SettingsFormat, key);
if(!_settings.Contains(formattedKey))
{
return TryGetAndMigrateFromOldKeyStore(key);
return TryGetAndMigrate(key);
}
var cs = _settings.GetValueOrDefault<string>(formattedKey);
@ -90,7 +104,7 @@ namespace Bit.Android.Services
public void Store(string key, byte[] dataBytes)
{
var formattedKey = string.Format(SettingsFormat, key);
CleanupOldKeyStore(key);
CleanupOld(key);
if(dataBytes == null)
{
_settings.Remove(formattedKey);
@ -115,18 +129,16 @@ namespace Bit.Android.Services
}
}
private void GenerateRsaKey()
private void GenerateStoreKey()
{
if(_keyStore.ContainsAlias(KeyAlias))
{
return;
}
var gen = KeyPairGenerator.GetInstance(KeyProperties.KeyAlgorithmRsa, AndroidKeyStore);
var subject = new X500Principal($"CN={KeyAlias}");
if(_oldAndroid)
{
var subject = new X500Principal($"CN={KeyAlias}");
var start = Calendar.Instance;
var end = Calendar.Instance;
end.Add(CalendarField.Year, 30);
@ -139,25 +151,26 @@ namespace Bit.Android.Services
.SetEndDate(end.Time)
.Build();
var gen = KeyPairGenerator.GetInstance(KeyProperties.KeyAlgorithmRsa, AndroidKeyStore);
gen.Initialize(spec);
gen.GenerateKeyPair();
}
else
{
var spec = new KeyGenParameterSpec.Builder(KeyAlias, KeyStorePurpose.Decrypt | KeyStorePurpose.Encrypt)
.SetCertificateSubject(subject)
.SetDigests(KeyProperties.DigestSha1)
.SetEncryptionPaddings(KeyProperties.EncryptionPaddingRsaOaep)
.SetBlockModes(KeyProperties.BlockModeGcm)
.SetEncryptionPaddings(KeyProperties.EncryptionPaddingNone)
.Build();
gen.Initialize(spec);
var gen = KeyGenerator.GetInstance(KeyProperties.KeyAlgorithmAes, AndroidKeyStore);
gen.Init(spec);
gen.GenerateKey();
}
}
gen.GenerateKeyPair();
}
private KeyStore.PrivateKeyEntry GetRsaKeyEntry()
private KeyStore.PrivateKeyEntry GetRsaKeyEntry(string alias)
{
return _keyStore.GetEntry(KeyAlias, null) as KeyStore.PrivateKeyEntry;
return _keyStore.GetEntry(alias, null) as KeyStore.PrivateKeyEntry;
}
private void GenerateAesKey()
@ -168,24 +181,40 @@ namespace Bit.Android.Services
}
var key = App.Utilities.Crypto.RandomBytes(512 / 8);
var encKey = RsaEncrypt(key);
_settings.AddOrUpdateValue(AesKey, Convert.ToBase64String(encKey));
var encKey = _oldAndroid ? RsaEncrypt(key) : AesEncrypt(key);
_settings.AddOrUpdateValue(AesKey, encKey);
}
private App.Models.SymmetricCryptoKey GetAesKey()
private App.Models.SymmetricCryptoKey GetAesKey(bool v1 = false)
{
try
{
var encKey = _settings.GetValueOrDefault<string>(AesKey);
var encKey = _settings.GetValueOrDefault<string>(v1 ? AesKeyV1 : AesKey);
if(encKey == null)
{
return null;
}
if(_oldAndroid || v1)
{
var encKeyBytes = Convert.FromBase64String(encKey);
var key = RsaDecrypt(encKeyBytes);
var key = RsaDecrypt(encKeyBytes, v1);
return new App.Models.SymmetricCryptoKey(key);
}
else
{
var parts = encKey.Split('|');
if(parts.Length < 2)
{
return null;
}
var ivBytes = Convert.FromBase64String(parts[0]);
var encKeyBytes = Convert.FromBase64String(parts[1]);
var key = AesDecrypt(ivBytes, encKeyBytes);
return new App.Models.SymmetricCryptoKey(key);
}
}
catch(Exception e)
{
Console.WriteLine("Cannot get AesKey.");
@ -196,20 +225,44 @@ namespace Bit.Android.Services
}
}
private byte[] RsaEncrypt(byte[] data)
private string AesEncrypt(byte[] input)
{
using(var entry = GetRsaKeyEntry())
using(var entry = _keyStore.GetKey(KeyAlias, null))
using(var cipher = Cipher.GetInstance(AesMode))
{
cipher.Init(CipherMode.EncryptMode, entry);
var encBytes = cipher.DoFinal(input);
var ivBytes = cipher.GetIV();
return $"{Convert.ToBase64String(ivBytes)}|{Convert.ToBase64String(encBytes)}";
}
}
private byte[] AesDecrypt(byte[] iv, byte[] encData)
{
using(var entry = _keyStore.GetKey(KeyAlias, null))
using(var cipher = Cipher.GetInstance(AesMode))
{
var spec = new GCMParameterSpec(128, iv);
cipher.Init(CipherMode.DecryptMode, entry, spec);
var decBytes = cipher.DoFinal(encData);
return decBytes;
}
}
private string RsaEncrypt(byte[] data)
{
using(var entry = GetRsaKeyEntry(KeyAlias))
using(var cipher = Cipher.GetInstance(_rsaMode))
{
cipher.Init(CipherMode.EncryptMode, entry.Certificate.PublicKey);
var cipherText = cipher.DoFinal(data);
return cipherText;
return Convert.ToBase64String(cipherText);
}
}
private byte[] RsaDecrypt(byte[] encData)
private byte[] RsaDecrypt(byte[] encData, bool v1)
{
using(var entry = GetRsaKeyEntry())
using(var entry = GetRsaKeyEntry(v1 ? KeyAliasV1 : KeyAlias))
using(var cipher = Cipher.GetInstance(_rsaMode))
{
if(_oldAndroid)
@ -226,25 +279,43 @@ namespace Bit.Android.Services
}
}
private byte[] TryGetAndMigrateFromOldKeyStore(string key)
private byte[] TryGetAndMigrate(string key)
{
if(_oldKeyStorageService.Contains(key))
{
var value = _oldKeyStorageService.Retrieve(key);
Store(key, value);
_oldKeyStorageService.Delete(key);
return value;
}
var formattedKeyV1 = string.Format(SettingsFormatV1, key);
if(_settings.Contains(formattedKeyV1))
{
var aesKeyV1 = GetAesKey(true);
if(aesKeyV1 != null)
{
var cs = _settings.GetValueOrDefault<string>(formattedKeyV1);
var value = App.Utilities.Crypto.AesCbcDecrypt(new App.Models.CipherString(cs), aesKeyV1);
Store(key, value);
return value;
}
}
return null;
}
private void CleanupOldKeyStore(string key)
private void CleanupOld(string key)
{
if(_oldKeyStorageService.Contains(key))
{
_oldKeyStorageService.Delete(key);
}
var formattedKeyV1 = string.Format(SettingsFormatV1, key);
if(_settings.Contains(formattedKeyV1))
{
_settings.Remove(formattedKeyV1);
}
}
}
}