public void SignHashDirectly()
{
KSI.Ksi ksi = GetKsi();
// Compute the hash first, use the input stream to provide the data to save memory for
// hashing very large documents
// In this example we simply use an input stream from an array of bytes but in practice it
// could be file input stream from a very large file (several GB)
IDataHasher dataHasher = KsiProvider.CreateDataHasher();
using (MemoryStream stream = new MemoryStream())
{
byte[] data = Encoding.UTF8.GetBytes("Imagine this is a large file");
stream.Write(data, 0, data.Length);
stream.Seek(0, SeekOrigin.Begin);
dataHasher.AddData(stream);
}
// Provide the signing method with the computed hash instead of document itself
IKsiSignature signature = ksi.Sign(dataHasher.GetHash());
// Persist signature to file
//using (FileStream stream = File.OpenRead("sample-file-for-signing.txt.ksig"))
//{
// signature.WriteTo(stream);
//}
}
public void SignSampleByteArray()
{
KSI.Ksi ksi = GetKsi();
// Whenever signing text data, make sure you control and know what the character set
// (encoding) was otherwise you may have trouble in the verification later.
byte[] document = Encoding.UTF8.GetBytes("This is my document");
// Sign it, the hash of the document is computed implicitly by the sign method
IKsiSignature signature = ksi.Sign(document);
// Persist signature to file
//using (FileStream stream = File.OpenRead("sample-file-for-signing.txt.ksig"))
//{
// signature.WriteTo(stream);
//}
}
public void CreateAndSignSampleFile()
{
KSI.Ksi ksi = GetKsi();
// Let's create a file to be singed
string inputFileName = "sample-file-for-signing.txt";
File.WriteAllText(inputFileName, "Sample file, generated for signing!");
IKsiSignature signature;
using (FileStream stream = File.OpenRead(inputFileName))
{
// Sign it, the hash of the document is computed implicitly by the sign method
signature = ksi.Sign(stream);
}
// Persist signature to file
using (FileStream stream = File.Create("sample-file-for-signing.txt.ksig"))
{
signature.WriteTo(stream);
}
}