C#

Create PEM-encoded PKCS#7 Detached Signature

See more Digital Signatures Examples

Demonstrates how to create a PKCS7 PEM-encoded object containing a detached signature. C#

bool success = false;

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

Chilkat.Cert cert = new Chilkat.Cert();

// Load the cert and private key.
success = cert.LoadPfxFile("qa_data/pfx/myCertAndKey.p12","password");
if (success != true) {
    Debug.WriteLine(cert.LastErrorText);
    return;
}

Chilkat.Crypt2 crypt = new Chilkat.Crypt2();

success = crypt.SetSigningCert(cert);
if (success != true) {
    Debug.WriteLine(crypt.LastErrorText);
    return;
}

// Use SHA-256
crypt.HashAlgorithm = "sha256";

// Hash the utf-8 byte representation of the string
crypt.Charset = "utf-8";

// Return the result in base64
crypt.EncodingMode = "base64Mime";

// Sign some text to create a detached signature (i.e. a signature that does not include the signed data)
string textToSign = "This is the text to be hashed and signed.";
string sigBase64 = crypt.SignStringENC(textToSign);
if (crypt.LastMethodSuccess != true) {
    Debug.WriteLine(crypt.LastErrorText);
    return;
}

Debug.WriteLine(sigBase64);

// The result:

// MIIWbgYJKoZIhvcNAQcCoIIWXzCCFlsCAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg
// ghMXMIIFuzCCA6OgAwIBAgIIVwoRl0LE48wwDQYJKoZIhvcNAQELBQAwazELMAkGA1UEBhMCSVQx
// ...
// ...

// If we want it in PEM format with just LF line-endings:
Chilkat.StringBuilder sb = new Chilkat.StringBuilder();
// Just LF line endings, not CRLF.
bool crlf = false;
sb.AppendLine("-----BEGIN PKCS7-----",crlf);
sb.Append(sigBase64);
sb.AppendLine("-----END PKCS7-----",crlf);
sb.ToLF();

// Save to a file.
sb.WriteFile("c:/temp/qa_output/sig.pem","utf-8",false);

// Examine..
Debug.WriteLine(sb.GetAsString());

// Result is:

// -----BEGIN PKCS7-----
// MIIWbgYJKoZIhvcNAQcCoIIWXzCCFlsCAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg
// ghMXMIIFuzCCA6OgAwIBAgIIVwoRl0LE48wwDQYJKoZIhvcNAQELBQAwazELMAkGA1UEBhMCSVQx
// DjAMBgNVBAcMBU1pbGFuMSMwIQYDVQQKDBpBY3RhbGlzIFMucC5BLi8wMzM1ODUyMDk2NzEnMCUG
// A1UEAwweQWN0YWxpcyBBdXRoZW50aWNhdGlvbiBSb290IENBMB4XDTExMDkyMjExMjIwMloXDTMw
// MDkyMjExMjIwMlowazELMAkGA1UEBhMCSVQxDjAMBgNVBAcMBU1pbGFuMSMwIQYDVQQKDBpBY3Rh
// bGlzIFMucC5BLi8wMzM1ODUyMDk2NzEnMCUGA1UEAwweQWN0YWxpcyBBdXRoZW50aWNhdGlvbiBS
// b290IENBMIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEAp8bEpSmkLO/lGMWwUKNvUTuf
// ClrJwkg4CsIcoBh/kbWHuUA/3R1oHwiD1S0eiKD4j1aPbZkCkpAW1V8IbInX4ay8IMKx4INRimlN
// AJZaby/ARH6jDuSRzVju3PvHHkVH3Se5CAGfpiEd9UEtL0z9KK3giq0itFZljoZUj5NDKd45Rnij
// MCO6zfB9E1fAXdKDa0hMxKufgFpbOr3JpyI/gCczWw63igxdBzcIy2zSekciRDXFzMwujt0q7bd9
// ...
// ...
// -----END PKCS7-----