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++

#include <CkCert.h>
#include <CkCrypt2.h>
#include <CkStringBuilder.h>

void ChilkatSample(void)
    {
    bool success = false;

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

    CkCert cert;

    // Load the cert and private key.
    success = cert.LoadPfxFile("qa_data/pfx/myCertAndKey.p12","password");
    if (success != true) {
        std::cout << cert.lastErrorText() << "\r\n";
        return;
    }

    CkCrypt2 crypt;

    success = crypt.SetSigningCert(cert);
    if (success != true) {
        std::cout << crypt.lastErrorText() << "\r\n";
        return;
    }

    // Use SHA-256
    crypt.put_HashAlgorithm("sha256");

    // Hash the utf-8 byte representation of the string
    crypt.put_Charset("utf-8");

    // Return the result in base64
    crypt.put_EncodingMode("base64Mime");

    // Sign some text to create a detached signature (i.e. a signature that does not include the signed data)
    const char *textToSign = "This is the text to be hashed and signed.";
    const char *sigBase64 = crypt.signStringENC(textToSign);
    if (crypt.get_LastMethodSuccess() != true) {
        std::cout << crypt.lastErrorText() << "\r\n";
        return;
    }

    std::cout << sigBase64 << "\r\n";

    // The result:

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

    // If we want it in PEM format with just LF line-endings:
    CkStringBuilder sb;
    // 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..
    std::cout << sb.getAsString() << "\r\n";

    // Result is:

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