(Unicode C++) JWS Using HMAC SHA-256

Creates a JSON Web Signatures (JWS) using HMAC SHA-256.

Note: This example requires Chilkat v9.5.0.66 or greater.

Chilkat C/C++ Library Downloads
MS Visual C/C++ Linux/CentOS C/C++ Alpine Linux C/C++ MAC OS X C/C++	armhf/aarch64 C/C++ C++ Builder iOS C/C++ Android C/C++	Solaris C/C++ MinGW C/C++

#include <CkJsonObjectW.h>
#include <CkJwsW.h>

void ChilkatSample(void)
    {
    // This requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // Note: This example requires Chilkat v9.5.0.66 or greater.

    bool success;

    // First create the JWS Protected Header
    CkJsonObjectW jwsProtHdr;
    jwsProtHdr.AppendString(L"typ",L"JWT");
    jwsProtHdr.AppendString(L"alg",L"HS256");
    wprintf(L"JWS Protected Header: %s\n",jwsProtHdr.emit());

    // Output:
    // JWS Protected Header: {"typ":"JWT","alg":"HS256"}

    CkJwsW jws;

    // Set the HMAC key:
    const wchar_t *hmacKey = L"AyM1SysPpbyDfgZld3umj1qzKObwVMkoqQ-EstJQLr_T-1qS0gZH75aKtMN3Yj0iPS4hcgUuTwjAzZr1Z9CAow";
    int signatureIndex = 0;
    jws.SetMacKey(signatureIndex,hmacKey,L"base64url");

    // Set the protected header:
    jws.SetProtectedHeader(signatureIndex,jwsProtHdr);

    // Set the payload.
    bool bIncludeBom = false;
    const wchar_t *payloadStr = L"In our village, folks say God crumbles up the old moon into stars.";
    jws.SetPayload(payloadStr,L"utf-8",bIncludeBom);

    // Create the JWS
    // By default, the compact serialization is used.
    const wchar_t *jwsCompact = jws.createJws();
    if (jws.get_LastMethodSuccess() != true) {
        wprintf(L"%s\n",jws.lastErrorText());
        return;
    }

    wprintf(L"JWS: %s\n",jwsCompact);

    // sample output:
    // JWS: eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu.bsYsi8HJ0N6OqGI1hKQ9QQRNPxxA5qMpcHLtOvXatk8

    // Now load the JWS, validate, and recover the original text.
    CkJwsW jws2;

    // Load the JWS.
    success = jws2.LoadJws(jwsCompact);

    // Set the MAC key used for validation.
    signatureIndex = 0;
    jws2.SetMacKey(signatureIndex,hmacKey,L"base64url");

    // Validate the 1st (and only) signature at index 0..
    int v = jws2.Validate(signatureIndex);
    if (v < 0) {
        // Perhaps Chilkat was not unlocked or the trial expired..
        wprintf(L"Method call failed for some other reason.\n");
        wprintf(L"%s\n",jws2.lastErrorText());
        return;
    }

    if (v == 0) {
        wprintf(L"Invalid signature.  The MAC key was incorrect, the JWS was invalid, or both.\n");
        return;
    }

    // If we get here, the signature was validated..
    wprintf(L"Signature validated.\n");

    // Recover the original content:
    wprintf(L"%s\n",jws2.getPayload(L"utf-8"));

    // Examine the protected header:
    CkJsonObjectW *joseHeader = jws2.GetProtectedHeader(signatureIndex);
    if (jws2.get_LastMethodSuccess() != true) {
        wprintf(L"No protected header found at the given index.\n");
        return;
    }

    joseHeader->put_EmitCompact(false);

    wprintf(L"Protected (JOSE) header:\n");
    wprintf(L"%s\n",joseHeader->emit());
    delete joseHeader;

    // Output:

    // 	Signature validated.
    // 	In our village, folks say God crumbles up the old moon into stars.
    // 	Protected (JOSE) header:
    // 	{ 
    // 	  "typ": "JWT",
    // 	  "alg": "HS256"
    // 	} 
    }