private static void TestSignVerifyDataRoundTrip(byte[] message, HashAlgorithmName hashAlgorithm, RSASignaturePadding paddingMode, int expectedSignatureLength)
{
using (RSA rsa = new RSACng())
{
byte[] signature = rsa.SignData(message, hashAlgorithm, paddingMode);
// RSACng.SignHash() is intentionally non-deterministic so we can verify that we got back a signature of the right length
// but nothing about the contents.
Assert.Equal(expectedSignatureLength, signature.Length);
bool verified = rsa.VerifyData(message, signature, hashAlgorithm, paddingMode);
Assert.True(verified);
}
}
/// <summary>
/// Generates signature based on RSA PKCS#v1.5 scheme using a specified CNG Key.
/// </summary>
/// <param name="dataToSign">Text to sign.</param>
/// <param name="rsaCngProvider">RSA CNG Provider.</param>
/// <returns>Signature</returns>
private byte[] RSASignHashedData(byte[] dataToSign, RSACng rsaCngProvider)
{
Debug.Assert((dataToSign != null) && (dataToSign.Length != 0));
Debug.Assert(rsaCngProvider != null);
return rsaCngProvider.SignData(dataToSign, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
}
private static void TestSignAndVerifyDataFromStream(int messageSize)
{
RSASignaturePadding padding = RSASignaturePadding.Pkcs1;
byte[] message = new byte[messageSize];
byte b = 5;
for (int i = 0; i < message.Length; i++)
{
message[i] = b;
b = (byte)((b << 4) | (i & 0xf));
}
byte[] hash = SHA1.Create().ComputeHash(message);
Stream stream = new MemoryStream(message);
using (RSA rsa = new RSACng())
{
byte[] signature = rsa.SignData(stream, HashAlgorithmName.SHA1, padding);
// Since the unique codepath being tested here is HashData(Stream...), the interesting test is to see if HashData(Stream...)
// computed the right hash. The easiest way to test that is to compute the hash ourselves and call VerifyHash.
bool verified = rsa.VerifyHash(hash, signature, HashAlgorithmName.SHA1, padding);
Assert.True(verified);
stream = new MemoryStream(message);
verified = rsa.VerifyData(stream, signature, HashAlgorithmName.SHA1, padding);
Assert.True(verified);
}
}
