Unicode C

Export a Private Key as DER into a BinData

Demonstrates the Chilkat PrivateKey.GetPkcsBd method, which exports the key as DER into a BinData. The first argument selects PKCS #1 (true) versus PKCS #8 (false), the second is the password (empty for unencrypted), and the third is the BinData that receives the bytes.

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: This is the in-memory binary export — the raw DER bytes land in a BinData ready to hash, encrypt, or hand to another API without a temporary file. One method covers several cases: the boolean picks the traditional (PKCS #1) versus modern (PKCS #8) structure, and a nonempty password produces an encrypted PKCS #8 export (with the cipher from Pkcs8EncryptAlg). Source any password securely.

Chilkat Unicode C Downloads

Download Chilkat for Unicode C

Unicode C

#include <C_CkPrivateKeyW.h>
#include <C_CkBinDataW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkPrivateKeyW privKey;
    const wchar_t *password;
    BOOL usePkcs1;
    HCkBinDataW bd;

    success = FALSE;

    //  Load a private key to export.
    privKey = CkPrivateKeyW_Create();
    success = CkPrivateKeyW_LoadPemFile(privKey,L"qa_data/private.pem");
    if (success == FALSE) {
        wprintf(L"%s\n",CkPrivateKeyW_lastErrorText(privKey));
        CkPrivateKeyW_Dispose(privKey);
        return;
    }

    //  The key password is not hard-coded in a real application; obtain it from an interactive
    //  prompt, environment variable, or a secrets vault.
    password = L"myKeyPassword";

    //  Export the key as DER into a BinData.  The 1st argument selects PKCS #1 (TRUE) versus PKCS #8
    //  (FALSE); the 2nd is the password (empty string for an unencrypted export); the 3rd is the
    //  BinData that receives the DER bytes.
    usePkcs1 = FALSE;
    bd = CkBinDataW_Create();
    success = CkPrivateKeyW_GetPkcsBd(privKey,usePkcs1,password,bd);
    if (success == FALSE) {
        wprintf(L"%s\n",CkPrivateKeyW_lastErrorText(privKey));
        CkPrivateKeyW_Dispose(privKey);
        CkBinDataW_Dispose(bd);
        return;
    }

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


    CkPrivateKeyW_Dispose(privKey);
    CkBinDataW_Dispose(bd);

    }