(C) Sign JSON to Create CAdES P7S Bytes

Demonstrates how to sign JSON using a certificate + private key from a .p12/.pfx to create a CAdES P7S byte array.

Chilkat C/C++ Library Downloads
MS Visual C/C++ Linux/CentOS C/C++ Alpine Linux C/C++ MAC OS X C/C++	armhf/aarch64 C/C++ C++ Builder iOS C/C++ Android C/C++	Solaris C/C++ MinGW C/C++

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

void ChilkatSample(void)
    {
    HCkCrypt2 crypt;
    HCkCert cert;
    BOOL success;
    HCkJsonObject jsonSigningAttrs;
    HCkByteData cadesP7s;
    const char *originalJson;

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

    crypt = CkCrypt2_Create();

    cert = CkCert_Create();
    success = CkCert_LoadPfxFile(cert,"qa_data/pfx/cert_test123.pfx","test123");
    if (success != TRUE) {
        printf("%s\n",CkCert_lastErrorText(cert));
        CkCrypt2_Dispose(crypt);
        CkCert_Dispose(cert);
        return;
    }

    // Tell the crypt component to use this cert.
    success = CkCrypt2_SetSigningCert(crypt,cert);
    if (success != TRUE) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        CkCrypt2_Dispose(crypt);
        CkCert_Dispose(cert);
        return;
    }

    // The CadesEnabled property applies to all methods that create PKCS7 signatures. 
    // To create a CAdES-BES signature, set this property equal to true. 
    CkCrypt2_putCadesEnabled(crypt,TRUE);

    CkCrypt2_putHashAlgorithm(crypt,"sha256");

    jsonSigningAttrs = CkJsonObject_Create();
    CkJsonObject_UpdateInt(jsonSigningAttrs,"contentType",1);
    CkJsonObject_UpdateInt(jsonSigningAttrs,"signingTime",1);
    CkJsonObject_UpdateInt(jsonSigningAttrs,"messageDigest",1);
    CkJsonObject_UpdateInt(jsonSigningAttrs,"signingCertificateV2",1);
    CkCrypt2_putSigningAttributes(crypt,CkJsonObject_emit(jsonSigningAttrs));

    // By default, all the certs in the chain of authentication are included in the signature.
    // If desired, we can choose to only include the signing certificate:
    CkCrypt2_putIncludeCertChain(crypt,FALSE);

    // Create the CAdES-BES attached signature, which contains the original data.
    CkCrypt2_putCharset(crypt,"utf-8");
    cadesP7s = CkByteData_Create();
    success = CkCrypt2_OpaqueSignString(crypt,"{ \"abc\": 123}",cadesP7s);
    if (CkCrypt2_getLastMethodSuccess(crypt) == FALSE) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        CkCrypt2_Dispose(crypt);
        CkCert_Dispose(cert);
        CkJsonObject_Dispose(jsonSigningAttrs);
        CkByteData_Dispose(cadesP7s);
        return;
    }

    // Verify the signature and extract the original JSON:
    originalJson = CkCrypt2_opaqueVerifyString(crypt,cadesP7s);
    if (CkCrypt2_getLastMethodSuccess(crypt) == FALSE) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        CkCrypt2_Dispose(crypt);
        CkCert_Dispose(cert);
        CkJsonObject_Dispose(jsonSigningAttrs);
        CkByteData_Dispose(cadesP7s);
        return;
    }

    printf("Original JSON: %s\n",originalJson);

    printf("Success!\n");


    CkCrypt2_Dispose(crypt);
    CkCert_Dispose(cert);
    CkJsonObject_Dispose(jsonSigningAttrs);
    CkByteData_Dispose(cadesP7s);

    }