/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this file,

 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "cbor-cpp/src/cbor.h"

#include "mozilla/dom/WebAuthnCBORUtil.h"

#include "mozilla/dom/WebAuthnUtil.h"

namespace mozilla {

namespace dom {

nsresult

CBOREncodePublicKeyObj(const CryptoBuffer& aPubKeyBuf,

                       /* out */ CryptoBuffer& aPubKeyObj)

{

  mozilla::dom::CryptoBuffer xBuf, yBuf;

  nsresult rv = U2FDecomposeECKey(aPubKeyBuf, xBuf, yBuf);

  if (NS_FAILED(rv)) {

    return rv;

  }

  // COSE_Key object. See https://tools.ietf.org/html/rfc8152#section-7

  cbor::output_dynamic cborPubKeyOut;

  cbor::encoder encoder(cborPubKeyOut);

  encoder.write_map(5);

  {

    encoder.write_int(1);   // kty

    encoder.write_int(2);   // EC2

    encoder.write_int(3);   // alg

    encoder.write_int(-7);  // ES256

    // See https://tools.ietf.org/html/rfc8152#section-13.1

    encoder.write_int(-1);  // crv

    encoder.write_int(1);   // P-256

    encoder.write_int(-2);  // x

    encoder.write_bytes(xBuf.Elements(), xBuf.Length());

    encoder.write_int(-3);  // y

    encoder.write_bytes(yBuf.Elements(), yBuf.Length());

  }

  if (!aPubKeyObj.Assign(cborPubKeyOut.data(), cborPubKeyOut.size())) {

    return NS_ERROR_OUT_OF_MEMORY;

  }

  return NS_OK;

}

nsresult

CBOREncodeFidoU2FAttestationObj(const CryptoBuffer& aAuthDataBuf,

                                const CryptoBuffer& aAttestationCertBuf,

                                const CryptoBuffer& aSignatureBuf,

                                /* out */ CryptoBuffer& aAttestationObj)

{

  /*

  Attestation Object, encoded in CBOR (description is CDDL)

  attObj = {

              authData: bytes,

              $$attStmtType

           }

  $$attStmtType //= (

                        fmt: "fido-u2f",

                        attStmt: u2fStmtFormat

                    )

  u2fStmtFormat = {

                      x5c: [ attestnCert: bytes, * (caCert: bytes) ],

                      sig: bytes

                  }

  */

  cbor::output_dynamic cborAttOut;

  cbor::encoder encoder(cborAttOut);

  encoder.write_map(3);

  {

    encoder.write_string("fmt");

    encoder.write_string("fido-u2f");

    encoder.write_string("attStmt");

    encoder.write_map(2);

    {

      encoder.write_string("sig");

      encoder.write_bytes(aSignatureBuf.Elements(), aSignatureBuf.Length());

      encoder.write_string("x5c");

      // U2F wire protocol can only deliver 1 certificate, so it's never a chain

      encoder.write_array(1);

      encoder.write_bytes(aAttestationCertBuf.Elements(), aAttestationCertBuf.Length());

    }

    encoder.write_string("authData");

    encoder.write_bytes(aAuthDataBuf.Elements(), aAuthDataBuf.Length());

  }

  if (!aAttestationObj.Assign(cborAttOut.data(), cborAttOut.size())) {

    return NS_ERROR_OUT_OF_MEMORY;

  }

  return NS_OK;

}

nsresult

CBOREncodeNoneAttestationObj(const CryptoBuffer& aAuthDataBuf,

                             /* out */ CryptoBuffer& aAttestationObj)

{

  /*

  Attestation Object, encoded in CBOR (description is CDDL)

  $$attStmtType //= (

                          fmt: "none",

                          attStmt: emptyMap

                      )

  emptyMap = {}

  */

  cbor::output_dynamic cborAttOut;

  cbor::encoder encoder(cborAttOut);

  encoder.write_map(3);

  {

    encoder.write_string("fmt");

    encoder.write_string("none");

    encoder.write_string("attStmt");

    encoder.write_map(0);

    encoder.write_string("authData");

    encoder.write_bytes(aAuthDataBuf.Elements(), aAuthDataBuf.Length());

  }

  if (!aAttestationObj.Assign(cborAttOut.data(), cborAttOut.size())) {

    return NS_ERROR_OUT_OF_MEMORY;

  }

  return NS_OK;

}

}

}