Sample code for 30+ languages & platforms
Unicode C

Generate an ECC Key (Public and Private)

See more ECC Examples

Demonstrates how to generate an ECC key and save both public and private parts.

Chilkat Unicode C Downloads

Unicode C
#include <C_CkPrngW.h>
#include <C_CkEccW.h>
#include <C_CkPrivateKeyW.h>
#include <C_CkPublicKeyW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkPrngW fortuna;
    const wchar_t *entropy;
    HCkEccW ecc;
    HCkPrivateKeyW privKey;
    HCkPublicKeyW pubKey;
    BOOL bPreferPkcs1;

    success = FALSE;

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

    // Create a Fortuna PRNG and seed it with system entropy.
    // This will be our source of random data for generating the ECC private key.
    fortuna = CkPrngW_Create();
    entropy = CkPrngW_getEntropy(fortuna,32,L"base64");
    success = CkPrngW_AddEntropy(fortuna,entropy,L"base64");

    ecc = CkEccW_Create();

    // Generate a random ECC private key on the secp256r1 curve.
    // Chilkat also supports other curves, such as secp384r1, secp521r1, and secp256k1.

    privKey = CkPrivateKeyW_Create();
    success = CkEccW_GenKey(ecc,L"secp256r1",fortuna,privKey);
    if (success == FALSE) {
        wprintf(L"%s\n",CkEccW_lastErrorText(ecc));
        CkPrngW_Dispose(fortuna);
        CkEccW_Dispose(ecc);
        CkPrivateKeyW_Dispose(privKey);
        return;
    }

    // Save the private key to PKCS8 encrypted PEM
    // (The private key can be saved in a variety of different formats. See the online reference documentation.)
    success = CkPrivateKeyW_SavePkcs8EncryptedPemFile(privKey,L"pemPassword",L"qa_output/eccPrivKey.pem");
    if (success != TRUE) {
        wprintf(L"%s\n",CkPrivateKeyW_lastErrorText(privKey));
    }

    // The private key PEM looks like this:

    // 	-----BEGIN ENCRYPTED PRIVATE KEY-----
    // 	MIHFMEAGCSqGSIb3DQEFDTAzMBsGCSqGSIb3DQEFDDAOBAhUmn+1/lwCIwICCAAw
    // 	FAYIKoZIhvcNAwcECPlyNXAXZO+oBIGAIvxvTENXJWbrCwSjh0QNxLecBotUpfI5
    // 	auOonLmwVMyt1ahMmNyVo/D+pnKQSE41Fg8fApM0DCDKZUOVCCcK1qirIsMPQkGp
    // 	klPJbvrQRVYgzBtU31uNB5y2wqhrIeepal1HXBvbkUK0nfJMbcdz/XAEIQu2HhTD
    // 	t6LMScPQld4=
    // 	-----END ENCRYPTED PRIVATE KEY-----

    // Now get the public key part from the private key.
    // (A public key is actually a subset of the private key.)
    pubKey = CkPublicKeyW_Create();
    CkPrivateKeyW_ToPublicKey(privKey,pubKey);

    // Save the public key to a PEM file.
    // (The public key can be saved in a variety of different formats. See the online reference documentation.)
    // For ECC keys, the 1st argument (bPreferPkcs1) is ignored and unused.
    bPreferPkcs1 = FALSE;
    success = CkPublicKeyW_SavePemFile(pubKey,bPreferPkcs1,L"qa_output/eccPubKey.pem");

    // The public key PEM looks like this:

    // 	-----BEGIN PUBLIC KEY-----
    // 	MIIBSzCCAQMGByqGSM49AgEwgfcCAQEwLAYHKoZIzj0BAQIhAP////8AAAABAAAA
    // 	AAAAAAAAAAAA////////////////MFsEIP////8AAAABAAAAAAAAAAAAAAAA////
    // 	///////////8BCBaxjXYqjqT57PrvVV2mIa8ZR0GsMxTsPY7zjw+J9JgSwMVAMSd
    // 	NgiG5wSTamZ44ROdJreBn36QBEEEaxfR8uEsQkf4vOblY6RA8ncDfYEt6zOg9KE5
    // 	RdiYwpZP40Li/hp/m47n60p8D54WK84zV2sxXs7LtkBoN79R9QIhAP////8AAAAA
    // 	//////////+85vqtpxeehPO5ysL8YyVRAgEBA0IABGdOH8uM6SfX3mdV+TR0mWp2
    // 	gfVRPlxWxwhOiowuNByBxmQz7ZR4CJY1XcN2zkUo5pzW73ZhGwgd2XTOvqPqG40=
    // 	-----END PUBLIC KEY-----
    // 

    wprintf(L"finished.\n");


    CkPrngW_Dispose(fortuna);
    CkEccW_Dispose(ecc);
    CkPrivateKeyW_Dispose(privKey);
    CkPublicKeyW_Dispose(pubKey);

    }