(C) Create JWT using a Brainpool EC Key

See more JSON Web Token (JWT) Examples

Demonstrates how to create a JWT using an EC private key. This is for JOSE headers having an "alg" member with any of the following values:

• BP160R1
• BP192R1
• BP224R1
• BP256R1
• BP320R1
• BP384R1
• BP512R1

This example also demonstrates how to include time constraints:

• nbf: Not Before Time
• exp: Expiration Time
• iat: Issue At Time

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#include <C_CkPrivateKey.h>
#include <C_CkJwt.h>
#include <C_CkJsonObject.h>

void ChilkatSample(void)
    {
    HCkPrivateKey privKey;
    BOOL success;
    HCkJwt jwt;
    HCkJsonObject jose;
    HCkJsonObject claims;
    int curDateTime;
    const char *token;

    // Demonstrates how to create a JWT using a brainpool EC private key.

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

    privKey = CkPrivateKey_Create();

    // Load a brainpool EC key.
    success = CkPrivateKey_LoadPemFile(privKey,"c:/qa_data/pem/ec_brainpool_privKey.pem");
    if (success != TRUE) {
        printf("%s\n",CkPrivateKey_lastErrorText(privKey));
        CkPrivateKey_Dispose(privKey);
        return;
    }

    // You can examine the curve name of the key you just loaded by getting the private in XML format:
    // <ECCKeyValue curve="CURVE_NAME">...</ECCKeyValue>
    printf("%s\n",CkPrivateKey_getXml(privKey));

    jwt = CkJwt_Create();

    // Build the JOSE header
    jose = CkJsonObject_Create();
    // Use the brainpool curve name matching the private key you just loaded.
    // Use "BP256R1", or "BP384R1", etc.   
    success = CkJsonObject_AppendString(jose,"alg","BP256R1");
    success = CkJsonObject_AppendString(jose,"typ","JWT");

    // Now build the JWT claims (also known as the payload)
    claims = CkJsonObject_Create();
    success = CkJsonObject_AppendString(claims,"iss","http://example.org");
    success = CkJsonObject_AppendString(claims,"sub","John");
    success = CkJsonObject_AppendString(claims,"aud","http://example.com");

    // Set the timestamp of when the JWT was created to now.
    curDateTime = CkJwt_GenNumericDate(jwt,0);
    success = CkJsonObject_AddIntAt(claims,-1,"iat",curDateTime);

    // Set the "not process before" timestamp to now.
    success = CkJsonObject_AddIntAt(claims,-1,"nbf",curDateTime);

    // Set the timestamp defining an expiration time (end time) for the token
    // to be now + 1 hour (3600 seconds)
    success = CkJsonObject_AddIntAt(claims,-1,"exp",curDateTime + 3600);

    // Produce the smallest possible JWT:
    CkJwt_putAutoCompact(jwt,TRUE);

    // Create the JWT token.  This is where the ECC signature is created.
    token = CkJwt_createJwtPk(jwt,CkJsonObject_emit(jose),CkJsonObject_emit(claims),privKey);

    printf("%s\n",token);


    CkPrivateKey_Dispose(privKey);
    CkJwt_Dispose(jwt);
    CkJsonObject_Dispose(jose);
    CkJsonObject_Dispose(claims);

    }