public static bool VerifySignature(DataSignature ds)
{
byte[] remoteText = ds.Data;
byte[] signHash = ds.Signature;
if (dsa == null)
{
dsa = new DSACryptoServiceProvider();
}
if (ds.PublicKey != null)
{
try
{
dsa.FromXmlString(ds.PublicKey);
return(dsa.VerifyData(remoteText, signHash));
}
catch
{
return(false);
}
}
else
{
return(true);
}
}
public static DataSignature CreateSignature(byte[] plainText)
{
DataSignature ds = new DataSignature();
if (plainText != null)
{
SHA1Managed sha1 = new SHA1Managed();
//if (dsa == null)
dsa = new DSACryptoServiceProvider();
DSASignatureFormatter formatter = new DSASignatureFormatter(dsa);
byte[] data = plainText;
byte[] hash = sha1.ComputeHash(data);
formatter.SetHashAlgorithm("SHA1");
byte[] signHash = formatter.CreateSignature(hash);
ds.Data = data;
ds.Signature = signHash;
ds.PublicKey = dsa.ToXmlString(false);
}
return(ds);
}