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Question:

I can sign a file with p7s on one computer, but a new computer doesn't let me

Mar 04 '16 at 11:32

I have this code that signs a file and then outputs a detached signature file. The code works perfectly on one machine, but I go to a newer machine and it does not work. I have tried all versions of chilkat and it won't generate the signature file, but the code compiles and has no issues. I copied the code below. Please HELP!

//in Nuget ChilkatDotNet4 void Main() { Chilkat.Crypt crypt = new Chilkat.Crypt();

crypt.UnlockComponent("UnlockCode");

// Read the PDF
System.IO.FileInfo fInfo = new System.IO.FileInfo(@"D:\AttidoMobile\manifest.json");
System.IO.BinaryReader br = new System.IO.BinaryReader(
    System.IO.File.OpenRead(@"D:\AttidoMobile\manifest.json"));
byte [] pdfBytes = br.ReadBytes((int)fInfo.Length);
br.Close();

// Indicate which digital certificate is to be used.
// This certificate must have the private key installed on the system.
Chilkat.Cert cert = new Chilkat.Cert();
// Replace this line with your own .cer or .p7b file.
cert.LoadFromFile(@"D:\AttidoMobile\pass.cer");
crypt.SetSigningCertificate(cert);

// Create the signature.
byte [] signature = crypt.CreateSignature(pdfBytes);

// Save the signature to a file.
System.IO.BinaryWriter bw = new System.IO.BinaryWriter(
    System.IO.File.Create(@"D:\AttidoMobile\signature"));
bw.Write(signature);
bw.Close();

// Now load the signature back into another byte array.
fInfo = new System.IO.FileInfo(@"D:\AttidoMobile\signature");
br = new System.IO.BinaryReader(
    System.IO.File.OpenRead(@"D:\AttidoMobile\signature"));
byte [] sigBytes = br.ReadBytes((int)fInfo.Length);
br.Close();

// This should be valid.
bool valid1 = crypt.VerifySignature(pdfBytes,sigBytes);

// Modify the data, and verify should return false.
pdfBytes[0] = 0xCC;
bool valid2 = crypt.VerifySignature(pdfBytes,sigBytes);

Console.WriteLine("valid1 = " + valid1 + ", valid2 = " + valid2);

}

// Define other methods and classes here

Accepted Answer

Answer

Ok, so I figured it out... Apparently the certificate also has to be in the certificate store. you just can't load the .cer file. I did all that and now its working on my new machine. The Last.ErrorText is what helped me though, so thanks for the tip!!!!