(Go) Create JWS using the Flattened JSON Serialization Format

Creates a JSON Web Signature (JWS) containing 1 signature and output using the flattened JSON serialization format.

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

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    // 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.

    // The JWS to be created will contain one signature using an ECDSA key.

    sbEccJwk := chilkat.NewStringBuilder()
    sbEccJwk.Append("{\"kty\":\"EC\",")
    sbEccJwk.Append("\"crv\":\"P-256\",")
    sbEccJwk.Append("\"x\":\"f83OJ3D2xF1Bg8vub9tLe1gHMzV76e8Tus9uPHvRVEU\",")
    sbEccJwk.Append("\"y\":\"x_FEzRu9m36HLN_tue659LNpXW6pCyStikYjKIWI5a0\",")
    sbEccJwk.Append("\"d\":\"jpsQnnGQmL-YBIffH1136cspYG6-0iY7X1fCE9-E9LI\"")
    sbEccJwk.Append("}")

    eccKey := chilkat.NewPrivateKey()
    // Note: This example loads the ECDSA key from JWK format.  Any format can be loaded
    // into the private key object. (See the online reference documentation..)
    success := eccKey.LoadJwk(*sbEccJwk.GetAsString())
    if success != true {
        fmt.Println(eccKey.LastErrorText())
        sbEccJwk.DisposeStringBuilder()
        eccKey.DisposePrivateKey()
        return
    }

    // ---------------------------------------------------
    // Prepare both a protected and unprotected header.

    jwsProtHdr := chilkat.NewJsonObject()
    jwsProtHdr.AppendString("alg","ES256")

    jwsUnprotHdr := chilkat.NewJsonObject()
    jwsUnprotHdr.AppendString("kid","myEcKey")

    // ---------------------------------------------------
    jws := chilkat.NewJws()

    jws.SetProtectedHeader(0,jwsProtHdr)
    jws.SetUnprotectedHeader(0,jwsUnprotHdr)

    jws.SetPrivateKey(0,eccKey)

    bIncludeBom := false
    payloadStr := "In our village, folks say God crumbles up the old moon into stars."
    jws.SetPayload(payloadStr,"utf-8",bIncludeBom)

    // ---------------------------------------------------
    // Create the JWS.
    // Indicate we prefer the non-compact, flattened serialization.
    jws.SetPreferCompact(false)
    jws.SetPreferFlattened(true)

    jwsStr := jws.CreateJws()
    if jws.LastMethodSuccess() != true {
        fmt.Println(jws.LastErrorText())
        sbEccJwk.DisposeStringBuilder()
        eccKey.DisposePrivateKey()
        jwsProtHdr.DisposeJsonObject()
        jwsUnprotHdr.DisposeJsonObject()
        jws.DisposeJws()
        return
    }

    // The jwsStr is contains the flattened JSON in the smallest possible size, which is a single line.
    // To get in human-readable format, load into a Chilkat JSON object and emit..
    json := chilkat.NewJsonObject()
    json.Load(*jwsStr)
    json.SetEmitCompact(false)
    fmt.Println(*json.Emit())

    // Sample output:

    // { 
    //   "payload": "SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu",
    //   "protected": "eyJhbGciOiJFUzI1NiJ9",
    //   "header": { 
    //     "kid": "myEcKey"
    //   },
    //   "signature": "b7V2UpDPytr-kMnM_YjiQ3E0J2ucOI9LYA7mt57vccrK1rb84j9areqgQcJwOA00aWGoz4hf6sMTBfobdcJEGg"
    // }

    sbEccJwk.DisposeStringBuilder()
    eccKey.DisposePrivateKey()
    jwsProtHdr.DisposeJsonObject()
    jwsUnprotHdr.DisposeJsonObject()
    jws.DisposeJws()
    json.DisposeJsonObject()