internal Stream DoGetDataStream(byte[] rawPassPhrase, bool clearPassPhrase)
{
//IL_012b: Unknown result type (might be due to invalid IL or missing references)
//IL_015a: Unknown result type (might be due to invalid IL or missing references)
try
{
SymmetricKeyAlgorithmTag symmetricKeyAlgorithmTag = keyData.EncAlgorithm;
KeyParameter parameters = PgpUtilities.DoMakeKeyFromPassPhrase(symmetricKeyAlgorithmTag, keyData.S2k, rawPassPhrase, clearPassPhrase);
byte[] secKeyData = keyData.GetSecKeyData();
if (secKeyData != null && secKeyData.Length > 0)
{
IBufferedCipher cipher = CipherUtilities.GetCipher(PgpUtilities.GetSymmetricCipherName(symmetricKeyAlgorithmTag) + "/CFB/NoPadding");
cipher.Init(forEncryption: false, new ParametersWithIV(parameters, new byte[cipher.GetBlockSize()]));
byte[] array = cipher.DoFinal(secKeyData);
symmetricKeyAlgorithmTag = (SymmetricKeyAlgorithmTag)array[0];
parameters = ParameterUtilities.CreateKeyParameter(PgpUtilities.GetSymmetricCipherName(symmetricKeyAlgorithmTag), array, 1, array.Length - 1);
}
IBufferedCipher bufferedCipher = CreateStreamCipher(symmetricKeyAlgorithmTag);
byte[] array2 = new byte[bufferedCipher.GetBlockSize()];
bufferedCipher.Init(forEncryption: false, new ParametersWithIV(parameters, array2));
encStream = (Stream)(object)BcpgInputStream.Wrap((Stream)(object)new CipherStream((Stream)(object)encData.GetInputStream(), bufferedCipher, null));
if (encData is SymmetricEncIntegrityPacket)
{
truncStream = new TruncatedStream(encStream);
string digestName = PgpUtilities.GetDigestName(HashAlgorithmTag.Sha1);
IDigest digest = DigestUtilities.GetDigest(digestName);
encStream = (Stream)(object)new DigestStream((Stream)(object)truncStream, digest, null);
}
if (Streams.ReadFully(encStream, array2, 0, array2.Length) < array2.Length)
{
throw new EndOfStreamException("unexpected end of stream.");
}
int num = encStream.ReadByte();
int num2 = encStream.ReadByte();
if (num < 0 || num2 < 0)
{
throw new EndOfStreamException("unexpected end of stream.");
}
bool flag = array2[array2.Length - 2] == (byte)num && array2[array2.Length - 1] == (byte)num2;
bool flag2 = num == 0 && num2 == 0;
if (!flag && !flag2)
{
throw new PgpDataValidationException("quick check failed.");
}
return(encStream);
}
catch (PgpException ex)
{
throw ex;
}
catch (global::System.Exception exception)
{
throw new PgpException("Exception creating cipher", exception);
}
}
/// <summary>Return the decrypted input stream, using the passed in passphrase.</summary>
public Stream GetDataStream(char[] passPhrase)
{
try
{
var keyAlgorithm = _keyData.EncAlgorithm;
var key = PgpUtilities.MakeKeyFromPassPhrase(
keyAlgorithm, _keyData.S2K, passPhrase);
var secKeyData = _keyData.GetSecKeyData();
if (secKeyData != null && secKeyData.Length > 0)
{
var keyCipher = CipherUtilities.GetCipher(
PgpUtilities.GetSymmetricCipherName(keyAlgorithm) + "/CFB/NoPadding");
keyCipher.Init(false,
new ParametersWithIV(key, new byte[keyCipher.GetBlockSize()]));
var keyBytes = keyCipher.DoFinal(secKeyData);
keyAlgorithm = (SymmetricKeyAlgorithmTag)keyBytes[0];
key = ParameterUtilities.CreateKeyParameter(
PgpUtilities.GetSymmetricCipherName(keyAlgorithm),
keyBytes, 1, keyBytes.Length - 1);
}
var c = CreateStreamCipher(keyAlgorithm);
var iv = new byte[c.GetBlockSize()];
c.Init(false, new ParametersWithIV(key, iv));
EncStream = BcpgInputStream.Wrap(new CipherStream(EncData.GetInputStream(), c, null));
if (EncData is SymmetricEncIntegrityPacket)
{
TruncStream = new TruncatedStream(EncStream);
var digestName = PgpUtilities.GetDigestName(HashAlgorithmTag.Sha1);
var digest = DigestUtilities.GetDigest(digestName);
EncStream = new DigestStream(TruncStream, digest, null);
}
if (Streams.ReadFully(EncStream, iv, 0, iv.Length) < iv.Length)
{
throw new EndOfStreamException("unexpected end of stream.");
}
var v1 = EncStream.ReadByte();
var v2 = EncStream.ReadByte();
if (v1 < 0 || v2 < 0)
{
throw new EndOfStreamException("unexpected end of stream.");
}
// Note: the oracle attack on the "quick check" bytes is not deemed
// a security risk for PBE (see PgpPublicKeyEncryptedData)
var repeatCheckPassed =
iv[iv.Length - 2] == (byte)v1 &&
iv[iv.Length - 1] == (byte)v2;
// Note: some versions of PGP appear to produce 0 for the extra
// bytes rather than repeating the two previous bytes
var zeroesCheckPassed = v1 == 0 && v2 == 0;
if (!repeatCheckPassed && !zeroesCheckPassed)
{
throw new PgpDataValidationException("quick check failed.");
}
return(EncStream);
}
catch (PgpException)
{
throw;
}
catch (Exception e)
{
throw new PgpException("Exception creating cipher", e);
}
}
