(C++) JWE using ECDH-ES, BP-256, A256GCM

See more JSON Web Encryption (JWE) Examples

Create a JWE with the following header:

	{
	  "alg": "ECDH-ES",
	  "enc": "A256GCM",
	  "exp": 1621957030,
	  "cty": "NJWT",
	  "epk": {
	    "kty": "EC",
	    "x": "QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w"
	    "y": "AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu"
	    "crv": "BP-256"
	  }
	}

Note: This example requires Chilkat v9.5.0.87 or greater.

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#include <CkJsonObject.h>
#include <CkPublicKey.h>
#include <CkJwt.h>
#include <CkJwe.h>

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

    bool success;

    // Load our brainpool BP-256 public key.

    // 	{
    // 	  "use": "enc",
    // 	  "kid": "puk_idp_enc",
    // 	  "kty": "EC",
    // 	  "crv": "BP-256",
    // 	  "x": "QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w",
    // 	  "y": "AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu"
    // 	}

    CkJsonObject json;
    json.UpdateString("use","enc");
    json.UpdateString("kid","puk_idp_enc");
    json.UpdateString("kty","EC");
    json.UpdateString("crv","BP-256");
    json.UpdateString("x","QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w");
    json.UpdateString("y","AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu");

    CkPublicKey pubkey;

    success = pubkey.LoadFromString(json.emit());
    if (success == false) {
        std::cout << pubkey.lastErrorText() << "\r\n";
        return;
    }

    // Build our protected header:

    // 	{
    // 	  "alg": "ECDH-ES",
    // 	  "enc": "A256GCM",
    // 	  "exp": 1621957030,
    // 	  "cty": "NJWT",
    // 	  "epk": {
    // 	    "kty": "EC",
    // 	    "x": "QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w"
    // 	    "y": "AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu"
    // 	    "crv": "BP-256"
    // 	  }
    // 	}

    // Use jwt only for getting the current date/time + 3600 seconds.
    CkJwt jwt;

    CkJsonObject jweProtHdr;
    jweProtHdr.UpdateString("alg","ECDH-ES");
    jweProtHdr.UpdateString("enc","A256GCM");
    jweProtHdr.UpdateInt("exp",jwt.GenNumericDate(3600));
    jweProtHdr.UpdateString("cty","NJWT");
    jweProtHdr.UpdateString("epk.kty","EC");
    jweProtHdr.UpdateString("epk.x","QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w");
    jweProtHdr.UpdateString("epk.y","AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu");
    jweProtHdr.UpdateString("epk.crv","BP-256");

    CkJwe jwe;
    jwe.SetProtectedHeader(jweProtHdr);
    jwe.SetPublicKey(0,pubkey);

    const char *plainText = "This is the text to be encrypted.";
    const char *strJwe = jwe.encrypt(plainText,"utf-8");
    if (jwe.get_LastMethodSuccess() != true) {
        std::cout << jwe.lastErrorText() << "\r\n";
        return;
    }

    std::cout << strJwe << "\r\n";

    std::cout << "Success." << "\r\n";
    }