(Unicode C) Sign PDF using PAdES-Baseline-B

See more PDF Signatures Examples

PAdES-Baseline-B is the most basic, entry-level profile of the PDF Advanced Electronic Signatures (PAdES) standard.

It means:

• A PDF contains a CMS/PKCS#7 detached signature over the document’s byte range.
• /SubFilter must be ETSI.CAdES.detached.
• The signer’s X.509 certificate is included inside the signature.
• The signature uses recognized secure algorithms (e.g., SHA-256 with RSA/ECDSA).
• It proves document integrity (no changes since signing) and signer authenticity (certificate identifies who signed).
• It does not include time-stamps, revocation data (CRL/OCSP), or long-term validation information — those appear only in higher levels (PAdES-Baseline-T, -LT, -LTA).

In short: Baseline-B = a standard PDF digital signature that ensures integrity and origin, but without time or revocation guarantees.

Chilkat C/C++ Library Downloads
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#include <C_CkPdfW.h>
#include <C_CkJsonObjectW.h>
#include <C_CkCertW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkPdfW pdf;
    HCkJsonObjectW json;
    HCkCertW cert;
    const wchar_t *outFilePath;

    success = FALSE;

    pdf = CkPdfW_Create();

    // Load a PDF to be signed.
    success = CkPdfW_LoadFile(pdf,L"c:/someDir/my.pdf");
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        return;
    }

    // Options for signing are specified in JSON.
    json = CkJsonObjectW_Create();

    CkJsonObjectW_UpdateString(json,L"subFilter",L"/ETSI.CAdES.detached");
    CkJsonObjectW_UpdateBool(json,L"signingCertificateV2",TRUE);
    CkJsonObjectW_UpdateBool(json,L"signingTime",TRUE);
    CkJsonObjectW_UpdateString(json,L"signingAlgorithm",L"pkcs");
    CkJsonObjectW_UpdateString(json,L"hashAlgorithm",L"sha256");

    // -----------------------------------------------------------
    // The following JSON settings define the signature appearance.
    CkJsonObjectW_UpdateInt(json,L"page",1);
    CkJsonObjectW_UpdateString(json,L"appearance.y",L"top");
    CkJsonObjectW_UpdateString(json,L"appearance.x",L"left");
    CkJsonObjectW_UpdateString(json,L"appearance.fontScale",L"10.0");
    CkJsonObjectW_UpdateString(json,L"appearance.text[0]",L"Digitally signed by: cert_cn");
    CkJsonObjectW_UpdateString(json,L"appearance.text[1]",L"current_dt");
    CkJsonObjectW_UpdateString(json,L"appearance.text[2]",L"Hello 123 ABC");

    // --------------------------------------------------------------
    // Load the signing certificate. (Use your own certificate.)
    // Note: There are other methods for using a certificate on an HSM (smartcard or token)
    // or from other sources, such as a cloud HSM, a Windows installed certificate,
    // or other file formats.
    cert = CkCertW_Create();
    success = CkCertW_LoadPfxFile(cert,L"c:/myPfxFiles/myPdfSigningCert.pfx",L"pfxPassword");
    if (success == FALSE) {
        wprintf(L"%s\n",CkCertW_lastErrorText(cert));
        CkPdfW_Dispose(pdf);
        CkJsonObjectW_Dispose(json);
        CkCertW_Dispose(cert);
        return;
    }

    // Once we have the certificate object, tell the PDF object to use it for signing
    success = CkPdfW_SetSigningCert(pdf,cert);
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        CkJsonObjectW_Dispose(json);
        CkCertW_Dispose(cert);
        return;
    }

    // Sign the PDF, creating the output file.
    outFilePath = L"c:/someDir/mySigned.pdf";
    success = CkPdfW_SignPdf(pdf,json,outFilePath);
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        CkJsonObjectW_Dispose(json);
        CkCertW_Dispose(cert);
        return;
    }

    wprintf(L"Success.\n");


    CkPdfW_Dispose(pdf);
    CkJsonObjectW_Dispose(json);
    CkCertW_Dispose(cert);

    }