Unicode C

Export a Public Key as DER into a BinData

Demonstrates the Chilkat PublicKey.GetDerBd method, which writes the public key as binary DER into a BinData. The first argument selects the representation (as for GetPem) and the second is the BinData that receives the bytes (its contents are replaced).

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: The in-memory binary export: the raw DER lands in a BinData ready to hash, transmit, or hand to another API without a temporary file. It is the BinData counterpart to the text exporters, and the first argument picks the same PKCS #1 versus SubjectPublicKeyInfo structure.

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Unicode C

#include <C_CkPublicKeyW.h>
#include <C_CkBinDataW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkPublicKeyW pubKey;
    BOOL preferPkcs1;
    HCkBinDataW bd;

    success = FALSE;

    //  Load a public key to export.  LoadFromFile inspects the content, so it accepts DER, PEM, XML,
    //  JWK, and other supported representations.
    pubKey = CkPublicKeyW_Create();
    success = CkPublicKeyW_LoadFromFile(pubKey,L"qa_data/public.pem");
    if (success == FALSE) {
        wprintf(L"%s\n",CkPublicKeyW_lastErrorText(pubKey));
        CkPublicKeyW_Dispose(pubKey);
        return;
    }

    //  Write the public key as binary DER into a BinData.  The 1st argument selects the representation
    //  (as for GetPem) and the 2nd is the BinData that receives the bytes (its contents are replaced).
    preferPkcs1 = FALSE;
    bd = CkBinDataW_Create();
    success = CkPublicKeyW_GetDerBd(pubKey,preferPkcs1,bd);
    if (success == FALSE) {
        wprintf(L"%s\n",CkPublicKeyW_lastErrorText(pubKey));
        CkPublicKeyW_Dispose(pubKey);
        CkBinDataW_Dispose(bd);
        return;
    }

    wprintf(L"Exported %d DER bytes.\n",CkBinDataW_getNumBytes(bd));


    CkPublicKeyW_Dispose(pubKey);
    CkBinDataW_Dispose(bd);

    }