private byte[] littleEndianToBigEndian(Java.Math.BigInteger bigInt)
{
byte[] input = bigInt.ToByteArray();
if (input[0] == 0x00)
{
return(input.Skip(1).ToArray());
}
return(input);
}
private KeyPair rsaKeyFromBytes(byte [] keyBytes)
{
try
{
int offset = 0;
int dataLen = 0;
int version = 0;
if (keyBytes.Length != 523 && keyBytes.Length != 2339)
{
offset += 1; // skip address version
version = BitConverter.ToInt32(keyBytes, offset);
offset += 4;
}
dataLen = BitConverter.ToInt32(keyBytes, offset);
offset += 4;
Java.Math.BigInteger modulus = bigEndianToLittleEndian(keyBytes.Skip(offset).Take(dataLen).ToArray());
offset += dataLen;
dataLen = BitConverter.ToInt32(keyBytes, offset);
offset += 4;
Java.Math.BigInteger exponent = bigEndianToLittleEndian(keyBytes.Skip(offset).Take(dataLen).ToArray());
offset += dataLen;
RSAPrivateCrtKeySpec privKeySpec = null;
if (keyBytes.Length > offset)
{
dataLen = BitConverter.ToInt32(keyBytes, offset);
offset += 4;
Java.Math.BigInteger P = bigEndianToLittleEndian(keyBytes.Skip(offset).Take(dataLen).ToArray());
offset += dataLen;
dataLen = BitConverter.ToInt32(keyBytes, offset);
offset += 4;
Java.Math.BigInteger Q = bigEndianToLittleEndian(keyBytes.Skip(offset).Take(dataLen).ToArray());
offset += dataLen;
dataLen = BitConverter.ToInt32(keyBytes, offset);
offset += 4;
Java.Math.BigInteger DP = bigEndianToLittleEndian(keyBytes.Skip(offset).Take(dataLen).ToArray());
offset += dataLen;
dataLen = BitConverter.ToInt32(keyBytes, offset);
offset += 4;
Java.Math.BigInteger DQ = bigEndianToLittleEndian(keyBytes.Skip(offset).Take(dataLen).ToArray());
offset += dataLen;
dataLen = BitConverter.ToInt32(keyBytes, offset);
offset += 4;
Java.Math.BigInteger InverseQ = bigEndianToLittleEndian(keyBytes.Skip(offset).Take(dataLen).ToArray());
offset += dataLen;
dataLen = BitConverter.ToInt32(keyBytes, offset);
offset += 4;
Java.Math.BigInteger D = bigEndianToLittleEndian(keyBytes.Skip(offset).Take(dataLen).ToArray());
offset += dataLen;
privKeySpec = new RSAPrivateCrtKeySpec(modulus, exponent, D, P, Q, DP, DQ, InverseQ);
}
RSAPublicKeySpec pubKeySpec = new RSAPublicKeySpec(modulus, exponent);
KeyFactory keyFactory = KeyFactory.GetInstance("RSA");
IPublicKey pubKey = keyFactory.GeneratePublic(pubKeySpec);
IPrivateKey privKey = null;
if (privKeySpec != null)
{
privKey = keyFactory.GeneratePrivate(privKeySpec);
}
return(new KeyPair(pubKey, privKey));
}catch (Exception)
{
Logging.warn("An exception occured while trying to reconstruct PKI from bytes");
}
return(null);
}