Authenticating with an NKey

    Handling challenge response may require more than just a setting in the connection options, depending on the client library.

    Java

    2. Options options = new Options.Builder().
    3.             server("nats://localhost:4222").
    4.             authHandler(new AuthHandler(){
    5.                 public char[] getID() {
    6.                     try {
    7.                         return theNKey.getPublicKey();
    8.                     } catch (GeneralSecurityException|IOException|NullPointerException ex) {
    9.                         return null;
    10.                     }
    11.                 }
    13.                 public byte[] sign(byte[] nonce) {
    14.                     try {
    15.                         return theNKey.sign(nonce);
    16.                     } catch (GeneralSecurityException|IOException|NullPointerException ex) {
    17.                         return null;
    18.                     }
    19.                 }
    21.                 public char[] getJWT() {
    22.                     return null;
    23.                 }
    24.             }).
    25.             build();
    27. // Do something with the connection
    29. nc.close();

    Python

    1. nc = NATS()
    3. async def error_cb(e):
    4.     print("Error:", e)
    6. await nc.connect("nats://localhost:4222",
    7.                  nkeys_seed="./path/to/nkeys/user.nk",
    8.                  error_cb=error_cb,
    9.                  )
    11. # Do something with the connection
    13. await nc.close()

    C

    1. static natsStatus
    2. sigHandler(
    3.     char            **customErrTxt,
    4.     unsigned char   **signature,
    5.     int             *signatureLength,
    6.     const char      *nonce,
    7.     void            *closure)
    8. {
    10.     // returned as `signatureLength`.
    11.     // If an error occurs the user can return specific error text through
    12.     // `customErrTxt`. The library will free this pointer.
    14.     return NATS_OK;
    15. }
    17. (...)
    19. natsConnection      *conn      = NULL;
    20. natsOptions         *opts      = NULL;
    21. natsStatus          s          = NATS_OK;
    22. const char          *pubKey    = "my public key......";
    24. s = natsOptions_Create(&opts);
    25. if (s == NATS_OK)
    26.     s = natsOptions_SetNKey(opts, pubKey, sigHandler, NULL);
    27. if (s == NATS_OK)
    28.     s = natsConnection_Connect(&conn, opts);
    30. (...)
    32. // Destroy objects that were created
    33. natsConnection_Destroy(conn);