public void decryptFile(string inputFileName, string outputFileName, string privateKey, bool OAEPpadding)
{
using (FileStream stReader = new FileStream(inputFileName, FileMode.Open, FileAccess.Read))
{
RSACryptoServiceProvider rsa = PEM.ImportPrivateKey(privateKey);
int blocksize = rsa.KeySize / 8;
if (ProgressConfigure != null)
{
ProgressConfigure(stReader.Length / blocksize);
}
using (FileStream stWriter = new FileStream(outputFileName, FileMode.OpenOrCreate, FileAccess.Write))
{
byte[] buff = new byte[blocksize];
while (stReader.Read(buff, 0, buff.Length) > 0)
{
byte[] buffDencrypted = rsa.Decrypt(buff, OAEPpadding);
stWriter.Write(buffDencrypted, 0, buffDencrypted.Length);
buff = new byte[blocksize];
if (ProgressChanged != null)
{
ProgressChanged();
}
}
}
}
}
public static string decrypt(string privateKey, string Hash, bool OAEPpadding)
{
string decryptedText = string.Empty;
RSACryptoServiceProvider rsa = PEM.ImportPrivateKey(privateKey);
byte[] inputBytes = Convert.FromBase64String(Hash);
int room = rsa.KeySize / 8;
int remainingBytes = inputBytes.Length;
int startIndex = 0;
while (remainingBytes > 0)
{
int lengthToDencrypt;
if (remainingBytes > room)
{
lengthToDencrypt = room;
}
else
{
lengthToDencrypt = remainingBytes;
}
byte[] block = new byte[lengthToDencrypt];
Array.Copy(inputBytes, startIndex, block, 0, lengthToDencrypt);
decryptedText += Encoding.ASCII.GetString(rsa.Decrypt(block, OAEPpadding));
startIndex += lengthToDencrypt;
remainingBytes -= lengthToDencrypt;
}
return(decryptedText);
}
public static Key getPublicKeyfromPrivateKey(string privateKey)
{
RSACryptoServiceProvider rsa = PEM.ImportPrivateKey(privateKey);
return(new Key()
{
privateKey = privateKey, publicKey = PEM.ExportPublicKey(rsa), keySize = rsa.KeySize
});
}
public static Key ReadPrivateKey(Stream FileStream)
{
Key myKey = new Key();
using (FileStream)
{
using (StreamReader reader = new StreamReader(FileStream))
{
myKey.privateKey = reader.ReadToEnd();
RSACryptoServiceProvider csp = PEM.ImportPrivateKey(myKey.privateKey);
myKey.publicKey = PEM.ExportPublicKey(PEM.ImportPrivateKey(myKey.privateKey));
myKey.keySize = csp.KeySize;
}
}
return(myKey);
}
public static bool validate(string key, bool isprivate)
{
try
{
RSACryptoServiceProvider rsa;
if (isprivate)
{
rsa = PEM.ImportPrivateKey(key);
}
else
{
rsa = PEM.ImportPublicKey(key);
}
return(true);
}
catch
{
return(false);
}
}
public static string Sign(string privateKey, string inputString, string HashAlgo)
{
RSACryptoServiceProvider rsa = PEM.ImportPrivateKey(privateKey);
return(Convert.ToBase64String(rsa.SignData(Encoding.ASCII.GetBytes(inputString), getHashingAlgorithm(HashAlgo))));
}