(Go) JWE using PBES2 Key Wrapping

Demonstrates how to create and decrypt a JWE that using PBES2 key wrapping.

This example demonstrates PBES2 with HMAC SHA-256 and A128KW wrapping. It is also possible to do the following by simply changing the "alg" parameter:

• PBES2 with HMAC SHA-384 and A192KW wrapping
• PBES2 with HMAC SHA-512 and A256KW wrapping

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

Chilkat Go Downloads Go Package for Windows, MacOS, Linux, Alpine Linux, Solaris

    // 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.

    var success bool
    plaintext := "Live long and prosper."

    jwe := chilkat.NewJwe()

    // First build the JWE Protected Header..
    jweProtHdr := chilkat.NewJsonObject()
    jweProtHdr.AppendString("alg","PBES2-HS256+A128KW")
    jweProtHdr.AppendString("enc","A128GCM")

    // PBES2 requires two additional parameters:
    // 1) A random salt parameter ("p2s") containing 8 or more bytes in base64url format.
    // 2) An iteration count parameter ("p2c").  A minimum count of 1000 is recommended.
    //    The iteration count is intended to make the PBES2 computation more expensive (time consuming)
    //    to prevent brute-force attacks.
    prng := chilkat.NewPrng()
    jweProtHdr.AppendString("p2s",*prng.GenRandom(16,"base64url"))
    jweProtHdr.AppendString("p2c","1000")

    fmt.Println("JWE Protected Header: ", *jweProtHdr.Emit())
    fmt.Println("--")

    // Don't forget to actually provide the protected header to the JWE object:
    jwe.SetProtectedHeader(jweProtHdr)

    // Set the PBES2 password
    recipientIndex := 0
    jwe.SetPassword(recipientIndex,"top secret")

    // Encrypt and return the JWE:
    strJwe := jwe.Encrypt(plaintext,"utf-8")
    if jwe.LastMethodSuccess() != true {
        fmt.Println(jwe.LastErrorText())
        jwe.DisposeJwe()
        jweProtHdr.DisposeJsonObject()
        prng.DisposePrng()
        return
    }

    // Show the JWE we just created:
    fmt.Println(*strJwe)

    // Decrypt the JWE.
    jwe2 := chilkat.NewJwe()
    success = jwe2.LoadJwe(*strJwe)
    if success != true {
        fmt.Println(jwe2.LastErrorText())
        jwe.DisposeJwe()
        jweProtHdr.DisposeJsonObject()
        prng.DisposePrng()
        jwe2.DisposeJwe()
        return
    }

    // Set the PBES2 password
    jwe2.SetPassword(recipientIndex,"top secret")

    // Decrypt.
    originalPlaintext := jwe2.Decrypt(0,"utf-8")
    if jwe2.LastMethodSuccess() != true {
        fmt.Println(jwe2.LastErrorText())
        jwe.DisposeJwe()
        jweProtHdr.DisposeJsonObject()
        prng.DisposePrng()
        jwe2.DisposeJwe()
        return
    }

    fmt.Println("original text: ")
    fmt.Println(*originalPlaintext)

    // Sample output:

    // JWE Protected Header: {"alg":"PBES2-HS256+A128KW","enc":"A128GCM","p2s":"z39rTEfRy1T1Yn_D1mZRlg","p2c":"1000"}
    // --
    // eyJhbGciOiJQQkVTMi1IUzI1NitBMTI4S1ciLCJlbmMiOiJBMTI4R0NNIiwicDJzIjoiejM5clRFZlJ5MVQxWW5fRDFtWlJsZyIsInAyYyI6IjEwMDAifQ.koYt6PrFmYwcwdcT7ZcvXHA1d-Xez5h4.luGlbvEnZp-7IsBOj42Yhw.YMTcfLf8Qe4zazozGV2OAu3cUdQ8Kg.rWub47ESWkc6IqZJTvSTmg
    // original text: 
    // Live long and prosper.

    jwe.DisposeJwe()
    jweProtHdr.DisposeJsonObject()
    prng.DisposePrng()
    jwe2.DisposeJwe()