C

Sign String to create a CAdES-T Signature

See more CAdES Examples

This example will sign a string to create a CAdEST-T signature.

Note: This example requires Chilkat v9.5.0.78 or greater.

C

#include <C_CkCrypt2.h>
#include <C_CkCert.h>
#include <C_CkJsonObject.h>
#include <C_CkBinData.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkCrypt2 crypt;
    HCkCert cert;
    HCkJsonObject attrs;
    const char *strToSign;
    HCkBinData bd;

    success = FALSE;

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

    crypt = CkCrypt2_Create();

    // This example will use the certificate + private key currently inserted into a smartcard reader.
    cert = CkCert_Create();

    // If we wish to provide the smartcard PIN (otherwise the user will be prompted by the operating system).
    CkCert_putSmartCardPin(cert,"000000");
    success = CkCert_LoadFromSmartcard(cert,"");
    if (success != TRUE) {
        printf("%s\n",CkCert_lastErrorText(cert));
        CkCrypt2_Dispose(crypt);
        CkCert_Dispose(cert);
        return;
    }

    // Note: It is also possible to use certs from .pfx/.p12, .pem, or other sources such as 
    // pre-installed Windows certificates.

    success = CkCrypt2_SetSigningCert(crypt,cert);

    // Use SHA-256 rather than the default of SHA-1
    CkCrypt2_putHashAlgorithm(crypt,"sha256");

    // Create JSON that tells Chilkat what signing attributes to include:
    attrs = CkJsonObject_Create();
    CkJsonObject_UpdateBool(attrs,"contentType",TRUE);
    CkJsonObject_UpdateBool(attrs,"signingTime",TRUE);
    CkJsonObject_UpdateBool(attrs,"messageDigest",TRUE);
    CkJsonObject_UpdateBool(attrs,"signingCertificateV2",TRUE);

    // A CAdES-T signature is one that includes a timestampToken created by an online TSA (time stamping authority).
    // We must include the TSA's URL, as well as a few options to indicate what is desired.
    // Except for the TSA URL, the options shown here are typically what you would need.
    CkJsonObject_UpdateBool(attrs,"timestampToken.enabled",TRUE);
    CkJsonObject_UpdateString(attrs,"timestampToken.tsaUrl","https://freetsa.org/tsr");
    CkJsonObject_UpdateBool(attrs,"timestampToken.addNonce",FALSE);
    CkJsonObject_UpdateBool(attrs,"timestampToken.requestTsaCert",TRUE);
    CkJsonObject_UpdateString(attrs,"timestampToken.hashAlg","sha256");

    CkCrypt2_putSigningAttributes(crypt,CkJsonObject_emit(attrs));

    strToSign = "THIS IS MY ID";

    bd = CkBinData_Create();
    CkBinData_AppendString(bd,strToSign,"utf-8");

    // This creates the CAdES-T signature.  During the signature creation, it
    // communicates with the TSA to get a timestampToken.
    // The contents of bd are signed and replaced with the CAdES-T signature (which embeds the original content).
    success = CkCrypt2_OpaqueSignBd(crypt,bd);
    if (success != TRUE) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        CkCrypt2_Dispose(crypt);
        CkCert_Dispose(cert);
        CkJsonObject_Dispose(attrs);
        CkBinData_Dispose(bd);
        return;
    }

    // Get the signature in base64 format:
    printf("%s\n",CkBinData_getEncoded(bd,"base64_mime"));

    // Or save the signature to a file.
    CkBinData_WriteFile(bd,"qa_output/cades-t_sample.p7m");

    printf("Success.\n");


    CkCrypt2_Dispose(crypt);
    CkCert_Dispose(cert);
    CkJsonObject_Dispose(attrs);
    CkBinData_Dispose(bd);

    }