public static SymmetricAlgorithm CreateSymAlgorithm(SymAlgorithms saAlgo)
{
SymmetricAlgorithm saReturn;
switch (saAlgo)
{
case SymAlgorithms.AES128:
saReturn = Rijndael.Create();
saReturn.BlockSize = 128;
saReturn.KeySize = 128;
break;
case SymAlgorithms.AES192:
saReturn = Rijndael.Create();
saReturn.BlockSize = 128;
saReturn.KeySize = 192;
break;
case SymAlgorithms.AES256:
saReturn = Rijndael.Create();
saReturn.BlockSize = 128;
saReturn.KeySize = 256;
break;
case SymAlgorithms.CAST5:
saReturn = CAST5.Create();
break;
case SymAlgorithms.Triple_DES:
saReturn = TripleDES.Create();
break;
default:
throw new System.Security.Cryptography.CryptographicException("The algorithm is not supported!");
}
return(saReturn);
}
public BigInteger[] GetDecryptedKeyMaterial(string strPassphrase)
{
BigInteger[] biKeys = new BigInteger[0];
if (this.bIsEncrypted)
{
SharpPrivacy.SharpPrivacyLib.Cipher.SymmetricAlgorithm saAlgo;
switch (this.SymmetricalAlgorithm)
{
case SymAlgorithms.AES128:
saAlgo = Rijndael.Create();
saAlgo.BlockSize = 128;
saAlgo.KeySize = 128;
break;
case SymAlgorithms.AES192:
saAlgo = Rijndael.Create();
saAlgo.BlockSize = 128;
saAlgo.KeySize = 192;
break;
case SymAlgorithms.AES256:
saAlgo = Rijndael.Create();
saAlgo.BlockSize = 128;
saAlgo.KeySize = 256;
break;
case SymAlgorithms.Triple_DES:
saAlgo = TripleDES.Create();
saAlgo.KeySize = 192;
break;
case SymAlgorithms.CAST5:
saAlgo = CAST5.Create();
break;
default:
throw(new System.NotSupportedException("Sorry, but the Algorithm that was used to encrypt the secret key data is not (yet) supported by SharpPrivacy!"));
}
saAlgo.Mode = CipherMode.CFB;
saAlgo.Key = this.S2KSpecifier.GetKey(strPassphrase, saAlgo.KeySize);
if (this.PublicKey.Version == PublicKeyPacketVersionNumbers.v3)
{
throw(new System.NotImplementedException("Sorry, but we have not yet implemented the decryption of v3 keys!"));
}
else if (this.PublicKey.Version == PublicKeyPacketVersionNumbers.v4)
{
//In v4 keys, everything - including mpi headers and checksum
//is encrypted. Should be a heck of a lot easier than for
//v3 keys.
saAlgo.IV = this.InitialVector;
saAlgo.Padding = PaddingMode.None;
byte[] bOutput = new byte[this.bEncryptedKeyMaterial.Length];
ICryptoTransform ictDec = saAlgo.CreateDecryptor();
ictDec.TransformBlock(bEncryptedKeyMaterial, 0, bEncryptedKeyMaterial.Length, ref bOutput, 0);
int iCurrentChecksum = 0;
for (int i = 0; i < bOutput.Length; i++)
{
iCurrentChecksum = (iCurrentChecksum + bOutput[i]) % 65536;
}
if (pkpPublicKey.Algorithm == AsymAlgorithms.DSA ||
pkpPublicKey.Algorithm == AsymAlgorithms.ElGama_Encrypt_Sign ||
pkpPublicKey.Algorithm == AsymAlgorithms.ElGamal_Encrypt_Only)
{
biKeys = new BigInteger[1];
try {
biKeys = BigInteger.ParseMPIs(bOutput, 1);
} catch (Exception) {
throw new Exception("Invalid Passphrase!");
}
}
else if (pkpPublicKey.Algorithm == AsymAlgorithms.RSA_Encrypt_Only ||
pkpPublicKey.Algorithm == AsymAlgorithms.RSA_Encrypt_Sign ||
pkpPublicKey.Algorithm == AsymAlgorithms.RSA_Sign_Only)
{
biKeys = new BigInteger[4];
try {
biKeys = BigInteger.ParseMPIs(bOutput, 4);
} catch (Exception) {
throw new Exception("Invalid Passphrase!");
}
}
}
}
else
{
//Key Material is not encrypted anyway
biKeys = this.DecryptedKeyMaterial;
}
return(biKeys);
}
public void EncryptKeyMaterial(BigInteger[] biGivenKeyMaterial, string strPassphrase)
{
this.biDecryptedKeyMaterial = biGivenKeyMaterial;
if (!bIsEncrypted)
{
return;
}
if (this.PublicKey.Version == PublicKeyPacketVersionNumbers.v4)
{
int iKeyMaterialLength = 0;
for (int i = 0; i < this.biDecryptedKeyMaterial.Length; i++)
{
iKeyMaterialLength += biDecryptedKeyMaterial[i].GetMPI().Length;
}
byte[] bData = new byte[iKeyMaterialLength + 2];
int iPos = 0;
for (int i = 0; i < this.biDecryptedKeyMaterial.Length; i++)
{
byte[] bMPI = biDecryptedKeyMaterial[i].GetMPI();
Array.Copy(bMPI, 0, bData, iPos, bMPI.Length);
iPos += bMPI.Length;
}
int iChecksum = 0;
for (int i = 0; i < bData.Length - 2; i++)
{
iChecksum = (iChecksum + bData[i]) % 65536;
}
bData[iPos++] = (byte)((iChecksum >> 8) & 0xFF);
bData[iPos++] = (byte)(iChecksum & 0xFF);
SharpPrivacy.SharpPrivacyLib.Cipher.SymmetricAlgorithm saAlgo;
switch (this.SymmetricalAlgorithm)
{
case SymAlgorithms.AES128:
saAlgo = Rijndael.Create();
saAlgo.BlockSize = 128;
saAlgo.KeySize = 128;
break;
case SymAlgorithms.AES192:
saAlgo = Rijndael.Create();
saAlgo.BlockSize = 128;
saAlgo.KeySize = 192;
break;
case SymAlgorithms.AES256:
saAlgo = Rijndael.Create();
saAlgo.BlockSize = 128;
saAlgo.KeySize = 256;
break;
case SymAlgorithms.Triple_DES:
saAlgo = TripleDES.Create();
saAlgo.KeySize = 192;
break;
case SymAlgorithms.CAST5:
saAlgo = CAST5.Create();
break;
default:
throw(new System.NotSupportedException("Sorry, but the Algorithm that was used to encrypt the secret key data is not (yet) supported by SharpPrivacy!"));
}
saAlgo.Mode = CipherMode.CFB;
saAlgo.Key = this.S2KSpecifier.GetKey(strPassphrase, saAlgo.KeySize);
saAlgo.IV = this.InitialVector;
saAlgo.Padding = PaddingMode.None;
byte[] bOutput = new byte[bData.Length];
ICryptoTransform ictEnc = saAlgo.CreateEncryptor();
ictEnc.TransformBlock(bData, 0, bData.Length, ref bOutput, 0);
byte[] bTmp = new byte[bData.Length];
Array.Copy(bOutput, 0, bTmp, 0, bTmp.Length);
bOutput = bTmp;
if (bOutput.Length != bData.Length)
{
throw new Exception("Encryption of the secret Key material did not work correctly. Look at the file SecretKeyPacket, function EncryptKeyMaterial()");
}
bEncryptedKeyMaterial = bOutput;
}
else
{
throw new Exception("Sorry, but we don't support v3 secret keys so far!");
}
this.bIsUpdated = true;
}