private bool CheckSignature(ISource source, string cellFileName, string cellPath, string signaturePath)
{
S63SignatureFile sig = new S63SignatureFile(source.OpenRead(signaturePath));
var certSig = sig.DataServerCertSignedBySA;
var publicKeyFromFile = sig.PublicKeyOfDSCert();// the whole second half the of the signature file -- Encoding.ASCII.GetBytes(LineRange(8, 8));
var pkHash = SHA1.ComputeHash(publicKeyFromFile);
if (!SA.VerifySignature(pkHash, certSig))
{
WriteVerbose($"Cell certificate not signed {cellFileName}");
return(false);
}
var cellHash = SHA1.ComputeHash(source.OpenRead(cellPath));
using (var dsaCell = new DSACryptoServiceProvider())
{
dsaCell.ImportParameters(new DSAParameters()
{
P = sig.BigP,
Q = sig.BigQ,
G = sig.BigG,
Y = sig.BigY,
});
return(dsaCell.VerifySignature(cellHash, sig.CellSignature));
}
}
public XmlSignature(XElement fileSignature)
{
var ns = S63SignaturesXmlFile.Namespace;
DataServerID = (string)fileSignature.Attribute("dataServerID");
FileLocation = (string)fileSignature.Element(ns + "fileLocation");
FileName = (string)fileSignature.Element(ns + "fileName");
string r = (string)fileSignature.Element(ns + "Signature").Element(ns + "R");
string s = (string)fileSignature.Element(ns + "Signature").Element(ns + "S");
SignatureR = S63SignatureFile.StringToByteArray(r);
SignatureS = S63SignatureFile.StringToByteArray(s);
}
public XmlDataServer(XElement dataServerElement)
{
var ns = S63SignaturesXmlFile.Namespace;
ID = (string)dataServerElement.Attribute("dataServerID");
string parameterP = (string)dataServerElement.Element(ns + "Parameters").Element(ns + "P");
string parameterQ = (string)dataServerElement.Element(ns + "Parameters").Element(ns + "Q");
string parameterG = (string)dataServerElement.Element(ns + "Parameters").Element(ns + "G");
string publicKeyY = (string)dataServerElement.Element(ns + "PublicKey").Element(ns + "Y");
string certR = (string)dataServerElement.Element(ns + "dataserverCertificate").Element(ns + "R");
string certS = (string)dataServerElement.Element(ns + "dataserverCertificate").Element(ns + "S");
BigP = S63SignatureFile.StringToByteArray(parameterP);
BigQ = S63SignatureFile.StringToByteArray(parameterQ);
BigG = S63SignatureFile.StringToByteArray(parameterG);
BigY = S63SignatureFile.StringToByteArray(publicKeyY);
CertR = S63SignatureFile.StringToByteArray(certR);
CertS = S63SignatureFile.StringToByteArray(certS);
// I found this bit fairly troubling to program. Formatting something in a very specific way and then taking the bytes!
StringBuilder sb = new StringBuilder();
sb.Append("// BIG p");
sb.Append("\r\n");
sb.Append(parameterP);
sb.Append(".\r\n");
sb.Append("// BIG q");
sb.Append("\r\n");
sb.Append(parameterQ);
sb.Append(".\r\n");
sb.Append("// BIG g");
sb.Append("\r\n");
sb.Append(parameterG);
sb.Append(".\r\n");
sb.Append("// BIG y");
sb.Append("\r\n");
sb.Append(publicKeyY);
sb.Append(".\r\n");
PublicKeyOfDSCert = Encoding.ASCII.GetBytes(sb.ToString());
}
