path: root/rpc_client.c

/*
 * rpc_client.c
 * ------------
 * Remote procedure call client-side private API implementation.
 *
 * Authors: Rob Austein, Paul Selkirk
 * Copyright (c) 2015-2018, NORDUnet A/S All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of the NORDUnet nor the names of its contributors may
 *   be used to endorse or promote products derived from this software
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <assert.h>

#include "hal.h"
#include "hal_internal.h"
#include "xdr_internal.h"
#include "hashsig.h"

#ifndef HAL_RPC_CLIENT_DEBUG
#define HAL_RPC_CLIENT_DEBUG 0
#endif

#if HAL_RPC_CLIENT_DEBUG
#include <stdio.h>
#define check(op) do { const hal_error_t _err_ = (op); if (_err_ != HAL_OK) { printf("%s returned %d (%s)\n", #op, _err_, hal_error_string(_err_)); return _err_; } } while (0)
#else
#define check(op) do { const hal_error_t _err_ = (op); if (_err_ != HAL_OK) { return _err_; } } while (0)
#endif

#define pad(n) (((n) + 3) & ~3)

#define nargs(n) ((n) * 4)

#if RPC_CLIENT != RPC_CLIENT_LOCAL

/*
 * Consolidate a bit of the repetitive code from the packet receive loop.
 * We're looking for a packet which is a response to the packet we sent,
 * so if the opcode is wrong, we discard and wait for another packet.
 */

static hal_error_t read_matching_packet(const rpc_func_num_t expected_func,
                                        uint8_t *inbuf,
                                        const size_t inbuf_max,
                                        const uint8_t **iptr,
                                        const uint8_t **ilimit)
{
  hal_client_handle_t dummy_client;
  uint32_t received_func;
  size_t ilen = inbuf_max;
  hal_error_t err;

  assert(inbuf != NULL && iptr != NULL && ilimit != NULL);

  do {

    if ((err = hal_rpc_recv(inbuf, &ilen)) != HAL_OK)
      return err;

    assert(ilen <= inbuf_max);
    *iptr = inbuf;
    *ilimit = inbuf + ilen;

    if ((err = hal_xdr_decode_int(iptr, *ilimit, &received_func))       == HAL_ERROR_XDR_BUFFER_OVERFLOW)
      continue;
    if (err != HAL_OK)
      return err;

    if ((err = hal_xdr_decode_int(iptr, *ilimit, &dummy_client.handle)) == HAL_ERROR_XDR_BUFFER_OVERFLOW)
      continue;
    if (err != HAL_OK)
      return err;

  } while (received_func != expected_func);

  return HAL_OK;
}

/*
 * RPC calls.
 *
 * In reading these, it helps to know that every call takes a minimum
 * of two arguments (function code and client handle, even if the
 * latter is just a dummy), and that every call returns a minimum of
 * three values (function code, client handle, and return status).
 * This may seem a bit redundant, but There Are Reasons:
 * read_matching_packet() wants to make sure the result we're getting
 * is from the function we thought we called, and having the client
 * handle always present in a known place vastly simplifies the task
 * of the client-side MUX daemon.
 */

static hal_error_t get_version(uint32_t *version)
{
  uint8_t outbuf[nargs(2)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(4)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_GET_VERSION));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_GET_VERSION, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  if (rpc_ret == HAL_OK) {
    check(hal_xdr_decode_int(&iptr, ilimit, version));
  }
  return rpc_ret;
}

static hal_error_t get_random(void *buffer, const size_t length)
{
  uint8_t outbuf[nargs(3)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(4) + pad(length)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  size_t rcvlen = length;
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_GET_RANDOM));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_xdr_encode_int(&optr, olimit, (uint32_t)length));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_GET_RANDOM, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  if (rpc_ret == HAL_OK) {
    check(hal_xdr_decode_variable_opaque(&iptr, ilimit, buffer, &rcvlen));
    // XXX check rcvlen vs length
  }
  return rpc_ret;
}

static hal_error_t set_pin(const hal_client_handle_t client,
                           const hal_user_t user,
                           const char * const pin, const size_t pin_len)
{
  uint8_t outbuf[nargs(4) + pad(pin_len)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(3)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_SET_PIN));
  check(hal_xdr_encode_int(&optr, olimit, client.handle));
  check(hal_xdr_encode_int(&optr, olimit, user));
  check(hal_xdr_encode_variable_opaque(&optr, olimit, (const uint8_t *)pin, pin_len));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_SET_PIN, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  return rpc_ret;
}

/*
 * We may end up wanting to wrap a client-side cache around the
 * login()/logout()/logout_all() calls and reimplement is_logged_in()
 * on the client side using that cache, so that access checks don't
 * need to cross the RPC boundary.  Then again, we might not, if the
 * RPC call is fast enough, so implementing all before the RPC would
 * qualify as premature optimization.  There aren't all that many
 * things on the client side that would use this anyway, so the whole
 * question may be moot.
 *
 * For now, we leave all of these as plain RPC calls, but we may want
 * to revisit this if the is_logged_in() call turns into a bottleneck.
 */

static hal_error_t login(const hal_client_handle_t client,
                         const hal_user_t user,
                         const char * const pin, const size_t pin_len)
{
  uint8_t outbuf[nargs(4) + pad(pin_len)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(3)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_LOGIN));
  check(hal_xdr_encode_int(&optr, olimit, client.handle));
  check(hal_xdr_encode_int(&optr, olimit, user));
  check(hal_xdr_encode_variable_opaque(&optr, olimit, (const uint8_t *)pin, pin_len));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_LOGIN, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  return rpc_ret;
}

static hal_error_t logout(const hal_client_handle_t client)
{
  uint8_t outbuf[nargs(2)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(3)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_LOGOUT));
  check(hal_xdr_encode_int(&optr, olimit, client.handle));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_LOGOUT, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  return rpc_ret;
}

static hal_error_t logout_all(void)
{
  uint8_t outbuf[nargs(2)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(3)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_LOGOUT_ALL));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_LOGOUT_ALL, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  return rpc_ret;
}

static hal_error_t is_logged_in(const hal_client_handle_t client,
                                const hal_user_t user)
{
  uint8_t outbuf[nargs(3)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(3)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_IS_LOGGED_IN));
  check(hal_xdr_encode_int(&optr, olimit, client.handle));
  check(hal_xdr_encode_int(&optr, olimit, user));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_IS_LOGGED_IN, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  return rpc_ret;
}

static hal_error_t hash_get_digest_len(const hal_digest_algorithm_t alg, size_t *length)
{
  uint8_t outbuf[nargs(3)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(4)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  uint32_t len32;
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_HASH_GET_DIGEST_LEN));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_xdr_encode_int(&optr, olimit, alg));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_HASH_GET_DIGEST_LEN, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  if (rpc_ret == HAL_OK) {
    check(hal_xdr_decode_int(&iptr, ilimit, &len32));
    *length = (size_t)len32;
  }
  return rpc_ret;
}

static hal_error_t hash_get_digest_algorithm_id(const hal_digest_algorithm_t alg,
                                                uint8_t *id, size_t *len, const size_t len_max)
{
  uint8_t outbuf[nargs(4)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(4) + pad(len_max)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_HASH_GET_DIGEST_ALGORITHM_ID));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_xdr_encode_int(&optr, olimit, alg));
  check(hal_xdr_encode_int(&optr, olimit, len_max));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_HASH_GET_DIGEST_ALGORITHM_ID,
                             inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  if (rpc_ret == HAL_OK) {
    *len = len_max;
    check(hal_xdr_decode_variable_opaque(&iptr, ilimit, id, len));
  }
  return rpc_ret;
}

static hal_error_t hash_get_algorithm(const hal_hash_handle_t hash, hal_digest_algorithm_t *alg)
{
  uint8_t outbuf[nargs(3)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(4)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  uint32_t alg32;
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_HASH_GET_ALGORITHM));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_xdr_encode_int(&optr, olimit, hash.handle));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_HASH_GET_ALGORITHM, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  if (rpc_ret == HAL_OK) {
    check(hal_xdr_decode_int(&iptr, ilimit, &alg32));
    *alg = (hal_digest_algorithm_t) alg32;
  }
  return rpc_ret;
}

static hal_error_t hash_initialize(const hal_client_handle_t client,
                                   const hal_session_handle_t session,
                                   hal_hash_handle_t *hash,
                                   const hal_digest_algorithm_t alg,
                                   const uint8_t * const key, const size_t key_len)
{
  uint8_t outbuf[nargs(5) + pad(key_len)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(4)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_HASH_INITIALIZE));
  check(hal_xdr_encode_int(&optr, olimit, client.handle));
  check(hal_xdr_encode_int(&optr, olimit, session.handle));
  check(hal_xdr_encode_int(&optr, olimit, alg));
  check(hal_xdr_encode_variable_opaque(&optr, olimit, key, key_len));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_HASH_INITIALIZE, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  if (rpc_ret == HAL_OK) {
    check(hal_xdr_decode_int(&iptr, ilimit, &hash->handle));
  }
  return rpc_ret;
}

static hal_error_t hash_update(const hal_hash_handle_t hash,
                               const uint8_t * data, const size_t length)
{
  uint8_t outbuf[nargs(4) + pad(length)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(3)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_HASH_UPDATE));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_xdr_encode_int(&optr, olimit, hash.handle));
  check(hal_xdr_encode_variable_opaque(&optr, olimit, data, length));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_HASH_UPDATE, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  return rpc_ret;
}

static hal_error_t hash_finalize(const hal_hash_handle_t hash,
                                 uint8_t *digest, const size_t length)
{
  uint8_t outbuf[nargs(4)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(4) + pad(length)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  size_t digest_len = length;
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_HASH_FINALIZE));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_xdr_encode_int(&optr, olimit, hash.handle));
  check(hal_xdr_encode_int(&optr, olimit, length));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_HASH_FINALIZE, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  if (rpc_ret == HAL_OK) {
    check(hal_xdr_decode_variable_opaque(&iptr, ilimit, digest, &digest_len));
    /* XXX check digest_len vs length */
  }
  return rpc_ret;
}

static hal_error_t pkey_remote_load(const hal_client_handle_t client,
                                    const hal_session_handle_t session,
                                    hal_pkey_handle_t *pkey,
                                    hal_uuid_t *name,
                                    const uint8_t * const der, const size_t der_len,
                                    const hal_key_flags_t flags)
{
  uint8_t outbuf[nargs(5) + pad(der_len)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(5) + pad(sizeof(name->uuid))];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  size_t name_len = sizeof(name->uuid);
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_LOAD));
  check(hal_xdr_encode_int(&optr, olimit, client.handle));
  check(hal_xdr_encode_int(&optr, olimit, session.handle));
  check(hal_xdr_encode_variable_opaque(&optr, olimit, der, der_len));
  check(hal_xdr_encode_int(&optr, olimit, flags));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_LOAD, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  if (rpc_ret == HAL_OK) {
    check(hal_xdr_decode_int(&iptr, ilimit, &pkey->handle));
    check(hal_xdr_decode_variable_opaque(&iptr, ilimit, name->uuid, &name_len));
    if (name_len != sizeof(name->uuid))
      return HAL_ERROR_KEY_NAME_TOO_LONG;
  }
  return rpc_ret;
}

static hal_error_t pkey_remote_open(const hal_client_handle_t client,
                                    const hal_session_handle_t session,
                                    hal_pkey_handle_t *pkey,
                                    const hal_uuid_t * const name)
{
  uint8_t outbuf[nargs(4) + pad(sizeof(name->uuid))], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(4)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_OPEN));
  check(hal_xdr_encode_int(&optr, olimit, client.handle));
  check(hal_xdr_encode_int(&optr, olimit, session.handle));
  check(hal_xdr_encode_variable_opaque(&optr, olimit, name->uuid, sizeof(name->uuid)));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_OPEN, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));

  if (rpc_ret == HAL_OK)
    check(hal_xdr_decode_int(&iptr, ilimit, &pkey->handle));

  return rpc_ret;
}

static hal_error_t pkey_remote_generate_rsa(const hal_client_handle_t client,
                                            const hal_session_handle_t session,
                                            hal_pkey_handle_t *pkey,
                                            hal_uuid_t *name,
                                            const unsigned key_len,
                                            const uint8_t * const exp, const size_t exp_len,
                                            const hal_key_flags_t flags)
{
  uint8_t outbuf[nargs(6) + pad(exp_len)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(5) + pad(sizeof(name->uuid))];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  size_t name_len = sizeof(name->uuid);
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_GENERATE_RSA));
  check(hal_xdr_encode_int(&optr, olimit, client.handle));
  check(hal_xdr_encode_int(&optr, olimit, session.handle));
  check(hal_xdr_encode_int(&optr, olimit, key_len));
  check(hal_xdr_encode_variable_opaque(&optr, olimit, exp, exp_len));
  check(hal_xdr_encode_int(&optr, olimit, flags));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_GENERATE_RSA, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));

  if (rpc_ret == HAL_OK) {
    check(hal_xdr_decode_int(&iptr, ilimit, &pkey->handle));
    check(hal_xdr_decode_variable_opaque(&iptr, ilimit, name->uuid, &name_len));
    if (name_len != sizeof(name->uuid))
      return HAL_ERROR_KEY_NAME_TOO_LONG;
  }

  return rpc_ret;
}

static hal_error_t pkey_remote_generate_ec(const hal_client_handle_t client,
                                           const hal_session_handle_t session,
                                           hal_pkey_handle_t *pkey,
                                           hal_uuid_t *name,
                                           const hal_curve_name_t curve,
                                           const hal_key_flags_t flags)
{
  uint8_t outbuf[nargs(5)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(5) + pad(sizeof(name->uuid))];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  size_t name_len = sizeof(name->uuid);
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_GENERATE_EC));
  check(hal_xdr_encode_int(&optr, olimit, client.handle));
  check(hal_xdr_encode_int(&optr, olimit, session.handle));
  check(hal_xdr_encode_int(&optr, olimit, curve));
  check(hal_xdr_encode_int(&optr, olimit, flags));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_GENERATE_EC, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));

  if (rpc_ret == HAL_OK) {
    check(hal_xdr_decode_int(&iptr, ilimit, &pkey->handle));
    check(hal_xdr_decode_variable_opaque(&iptr, ilimit, name->uuid, &name_len));
    if (name_len != sizeof(name->uuid))
      return HAL_ERROR_KEY_NAME_TOO_LONG;
  }

  return rpc_ret;
}

static hal_error_t pkey_remote_generate_hashsig(const hal_client_handle_t client,
                                                const hal_session_handle_t session,
                                                hal_pkey_handle_t *pkey,
                                                hal_uuid_t *name,
                                                const size_t hss_levels,
                                                const lms_algorithm_t lms_type,
                                                const lmots_algorithm_t lmots_type,
                                                const hal_key_flags_t flags)
{
  uint8_t outbuf[nargs(7)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(5) + pad(sizeof(name->uuid))];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  size_t name_len = sizeof(name->uuid);
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_GENERATE_HASHSIG));
  check(hal_xdr_encode_int(&optr, olimit, client.handle));
  check(hal_xdr_encode_int(&optr, olimit, session.handle));
  check(hal_xdr_encode_int(&optr, olimit, (uint32_t)hss_levels));
  check(hal_xdr_encode_int(&optr, olimit, (uint32_t)lms_type));
  check(hal_xdr_encode_int(&optr, olimit, (uint32_t)lmots_type));
  check(hal_xdr_encode_int(&optr, olimit, flags));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_GENERATE_HASHSIG, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));

  if (rpc_ret == HAL_OK) {
    check(hal_xdr_decode_int(&iptr, ilimit, &pkey->handle));
    check(hal_xdr_decode_variable_opaque(&iptr, ilimit, name->uuid, &name_len));
    if (name_len != sizeof(name->uuid))
      return HAL_ERROR_KEY_NAME_TOO_LONG;
  }

  return rpc_ret;
}

static hal_error_t pkey_remote_close(const hal_pkey_handle_t pkey)
{
  uint8_t outbuf[nargs(3)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(3)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_CLOSE));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_xdr_encode_int(&optr, olimit, pkey.handle));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_CLOSE, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  return rpc_ret;
}

static hal_error_t pkey_remote_delete(const hal_pkey_handle_t pkey)
{
  uint8_t outbuf[nargs(3)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(3)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_DELETE));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_xdr_encode_int(&optr, olimit, pkey.handle));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_DELETE, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  return rpc_ret;
}

static hal_error_t pkey_remote_get_key_type(const hal_pkey_handle_t pkey,
                                            hal_key_type_t *type)
{
  uint8_t outbuf[nargs(3)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(4)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  uint32_t type32;
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_GET_KEY_TYPE));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_xdr_encode_int(&optr, olimit, pkey.handle));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_GET_KEY_TYPE, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  if (rpc_ret == HAL_OK) {
    check(hal_xdr_decode_int(&iptr, ilimit, &type32));
    *type = (hal_key_type_t)type32;
  }
  return rpc_ret;
}

static hal_error_t pkey_remote_get_key_curve(const hal_pkey_handle_t pkey,
                                             hal_curve_name_t *curve)
{
  uint8_t outbuf[nargs(3)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(4)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  uint32_t curve32;
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_GET_KEY_CURVE));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_xdr_encode_int(&optr, olimit, pkey.handle));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_GET_KEY_CURVE, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  if (rpc_ret == HAL_OK) {
    check(hal_xdr_decode_int(&iptr, ilimit, &curve32));
    *curve = (hal_curve_name_t)curve32;
  }
  return rpc_ret;
}

static hal_error_t pkey_remote_get_key_flags(const hal_pkey_handle_t pkey,
                                             hal_key_flags_t *flags)
{
  uint8_t outbuf[nargs(3)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(4)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  uint32_t flags32;
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_GET_KEY_FLAGS));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_xdr_encode_int(&optr, olimit, pkey.handle));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_GET_KEY_FLAGS, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  if (rpc_ret == HAL_OK) {
    check(hal_xdr_decode_int(&iptr, ilimit, &flags32));
    *flags = (hal_key_flags_t)flags32;
  }
  return rpc_ret;
}

static size_t pkey_remote_get_public_key_len(const hal_pkey_handle_t pkey)
{
  uint8_t outbuf[nargs(3)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(4)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  uint32_t len32;
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_GET_PUBLIC_KEY_LEN));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_xdr_encode_int(&optr, olimit, pkey.handle));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_GET_PUBLIC_KEY_LEN, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  if (rpc_ret == HAL_OK &&
      hal_xdr_decode_int(&iptr, ilimit, &len32) == HAL_OK)
    return (size_t)len32;

  return 0;
}

static hal_error_t pkey_remote_get_public_key(const hal_pkey_handle_t pkey,
                                              uint8_t *der, size_t *der_len, const size_t der_max)
{
  uint8_t outbuf[nargs(4)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(4) + pad(der_max)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_GET_PUBLIC_KEY));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_xdr_encode_int(&optr, olimit, pkey.handle));
  check(hal_xdr_encode_int(&optr, olimit, der_max));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_GET_PUBLIC_KEY, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  if (rpc_ret == HAL_OK) {
    *der_len = der_max;
    check(hal_xdr_decode_variable_opaque(&iptr, ilimit, der, der_len));
  }
  return rpc_ret;
}

static hal_error_t pkey_remote_sign(const hal_pkey_handle_t pkey,
                                    const hal_hash_handle_t hash,
                                    const uint8_t * const input, const size_t input_len,
                                    uint8_t * signature, size_t *signature_len, const size_t signature_max)
{
  uint8_t outbuf[nargs(6) + pad(input_len)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(4) + pad(signature_max)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_SIGN));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_xdr_encode_int(&optr, olimit, pkey.handle));
  check(hal_xdr_encode_int(&optr, olimit, hash.handle));
  check(hal_xdr_encode_variable_opaque(&optr, olimit, input, input_len));
  check(hal_xdr_encode_int(&optr, olimit, signature_max));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_SIGN, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  if (rpc_ret == HAL_OK) {
    *signature_len = signature_max;
    check(hal_xdr_decode_variable_opaque(&iptr, ilimit, signature, signature_len));
  }
  return rpc_ret;
}

static hal_error_t pkey_remote_verify(const hal_pkey_handle_t pkey,
                                      const hal_hash_handle_t hash,
                                      const uint8_t * const input, const size_t input_len,
                                      const uint8_t * const signature, const size_t signature_len)
{
  uint8_t outbuf[nargs(6) + pad(input_len) + pad(signature_len)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(3)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_VERIFY));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_xdr_encode_int(&optr, olimit, pkey.handle));
  check(hal_xdr_encode_int(&optr, olimit, hash.handle));
  check(hal_xdr_encode_variable_opaque(&optr, olimit, input, input_len));
  check(hal_xdr_encode_variable_opaque(&optr, olimit, signature, signature_len));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_VERIFY, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  return rpc_ret;
}

static hal_error_t pkey_remote_match(const hal_client_handle_t client,
                                     const hal_session_handle_t session,
                                     const hal_key_type_t type,
                                     const hal_curve_name_t curve,
                                     const hal_key_flags_t mask,
                                     const hal_key_flags_t flags,
                                     const hal_pkey_attribute_t *attributes,
                                     const unsigned attributes_len,
                                     unsigned *state,
                                     hal_uuid_t *result,
                                     unsigned *result_len,
                                     const unsigned result_max,
                                     const hal_uuid_t * const previous_uuid)
{
  size_t attributes_buffer_len = 0;
  if (attributes != NULL)
    for (int i = 0; i < attributes_len; i++)
      attributes_buffer_len += pad(attributes[i].length);

  uint8_t outbuf[nargs(11 + attributes_len * 2) + attributes_buffer_len + pad(sizeof(hal_uuid_t))];
  uint8_t *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(5 + result_max) + pad(result_max * sizeof(hal_uuid_t))];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_MATCH));
  check(hal_xdr_encode_int(&optr, olimit, client.handle));
  check(hal_xdr_encode_int(&optr, olimit, session.handle));
  check(hal_xdr_encode_int(&optr, olimit, type));
  check(hal_xdr_encode_int(&optr, olimit, curve));
  check(hal_xdr_encode_int(&optr, olimit, mask));
  check(hal_xdr_encode_int(&optr, olimit, flags));
  check(hal_xdr_encode_int(&optr, olimit, attributes_len));
  if (attributes != NULL) {
    for (int i = 0; i < attributes_len; i++) {
      check(hal_xdr_encode_int(&optr, olimit, attributes[i].type));
      check(hal_xdr_encode_variable_opaque(&optr, olimit, attributes[i].value, attributes[i].length));
    }
  }
  check(hal_xdr_encode_int(&optr, olimit, *state));
  check(hal_xdr_encode_int(&optr, olimit, result_max));
  check(hal_xdr_encode_variable_opaque(&optr, olimit, previous_uuid->uuid, sizeof(previous_uuid->uuid)));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_MATCH, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  if (rpc_ret == HAL_OK) {
    uint32_t array_len, ustate;
    *result_len = 0;
    check(hal_xdr_decode_int(&iptr, ilimit, &ustate));
    *state = ustate;
    check(hal_xdr_decode_int(&iptr, ilimit, &array_len));
    for (int i = 0; i < array_len; ++i) {
      size_t uuid_len = sizeof(result[i].uuid);
      check(hal_xdr_decode_variable_opaque(&iptr, ilimit, result[i].uuid, &uuid_len));
      if (uuid_len != sizeof(result[i].uuid))
        return HAL_ERROR_KEY_NAME_TOO_LONG;
    }
    *result_len = array_len;
  }
  return rpc_ret;
}

static hal_error_t pkey_remote_set_attributes(const hal_pkey_handle_t pkey,
                                             const hal_pkey_attribute_t *attributes,
                                             const unsigned attributes_len)
{
  size_t outbuf_len = nargs(4 + 2 * attributes_len);
  for (int i = 0; i < attributes_len; i++)
    outbuf_len += pad(attributes[i].length);

  uint8_t outbuf[outbuf_len], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(3)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_SET_ATTRIBUTES));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_xdr_encode_int(&optr, olimit, pkey.handle));
  check(hal_xdr_encode_int(&optr, olimit, attributes_len));
  for (int i = 0; i < attributes_len; i++) {
    check(hal_xdr_encode_int(&optr, olimit, attributes[i].type));
    if (attributes[i].length == HAL_PKEY_ATTRIBUTE_NIL)
      check(hal_xdr_encode_int(&optr, olimit, HAL_PKEY_ATTRIBUTE_NIL));
    else
      check(hal_xdr_encode_variable_opaque(&optr, olimit, attributes[i].value, attributes[i].length));
  }
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_SET_ATTRIBUTES, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  return rpc_ret;
}

static hal_error_t pkey_remote_get_attributes(const hal_pkey_handle_t pkey,
                                              hal_pkey_attribute_t *attributes,
                                              const unsigned attributes_len,
                                              uint8_t *attributes_buffer,
                                              const size_t attributes_buffer_len)
{
  /* inbuf[] here includes one extra word per attribute for padding */
  uint8_t outbuf[nargs(5 + attributes_len)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(3 + 3 * attributes_len) + attributes_buffer_len];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_GET_ATTRIBUTES));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_xdr_encode_int(&optr, olimit, pkey.handle));
  check(hal_xdr_encode_int(&optr, olimit, attributes_len));
  for (int i = 0; i < attributes_len; i++)
    check(hal_xdr_encode_int(&optr, olimit, attributes[i].type));
  check(hal_xdr_encode_int(&optr, olimit, attributes_buffer_len));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_GET_ATTRIBUTES, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  if (rpc_ret == HAL_OK) {
    uint8_t *abuf = attributes_buffer;
    uint32_t u32;
    check(hal_xdr_decode_int(&iptr, ilimit, &u32));
    if (u32 != attributes_len)
      return HAL_ERROR_RPC_PROTOCOL_ERROR;
    for (int i = 0; i < attributes_len; i++) {
      check(hal_xdr_decode_int(&iptr, ilimit, &u32));
      if (u32 != attributes[i].type)
        return HAL_ERROR_RPC_PROTOCOL_ERROR;
      if (attributes_buffer_len == 0) {
        check(hal_xdr_decode_int(&iptr, ilimit, &u32));
        attributes[i].value  = NULL;
        attributes[i].length = u32;
      }
      else {
        size_t len = attributes_buffer + attributes_buffer_len - abuf;
        check(hal_xdr_decode_variable_opaque(&iptr, ilimit, abuf, &len));
        attributes[i].value  = abuf;
        attributes[i].length = len;
        abuf += u32;
      }
    }
  }
  return rpc_ret;
}

static hal_error_t pkey_remote_export(const hal_pkey_handle_t pkey,
                                      const hal_pkey_handle_t kekek,
                                      uint8_t *pkcs8, size_t *pkcs8_len, const size_t pkcs8_max,
                                      uint8_t *kek,   size_t *kek_len,   const size_t kek_max)
{
  uint8_t outbuf[nargs(6)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(5) + pad(pkcs8_max) + pad(kek_max)];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  hal_client_handle_t dummy_client = {0};
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_EXPORT));
  check(hal_xdr_encode_int(&optr, olimit, dummy_client.handle));
  check(hal_xdr_encode_int(&optr, olimit, pkey.handle));
  check(hal_xdr_encode_int(&optr, olimit, kekek.handle));
  check(hal_xdr_encode_int(&optr, olimit, pkcs8_max));
  check(hal_xdr_encode_int(&optr, olimit, kek_max));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_EXPORT, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));
  if (rpc_ret == HAL_OK) {
    *pkcs8_len = pkcs8_max;
    check(hal_xdr_decode_variable_opaque(&iptr, ilimit, pkcs8, pkcs8_len));
    *kek_len = kek_max;
    check(hal_xdr_decode_variable_opaque(&iptr, ilimit, kek, kek_len));
  }
  return rpc_ret;
}

static hal_error_t pkey_remote_import(const hal_client_handle_t client,
                                      const hal_session_handle_t session,
                                      hal_pkey_handle_t *pkey,
                                      hal_uuid_t *name,
                                      const hal_pkey_handle_t kekek,
                                      const uint8_t * const pkcs8, const size_t pkcs8_len,
                                      const uint8_t * const kek,   const size_t kek_len,
                                      const hal_key_flags_t flags)
{
  uint8_t outbuf[nargs(7) + pad(pkcs8_len) + pad(kek_len)], *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
  uint8_t inbuf[nargs(5) + pad(sizeof(name->uuid))];
  const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
  size_t name_len = sizeof(name->uuid);
  hal_error_t rpc_ret;

  check(hal_xdr_encode_int(&optr, olimit, RPC_FUNC_PKEY_IMPORT));
  check(hal_xdr_encode_int(&optr, olimit, client.handle));
  check(hal_xdr_encode_int(&optr, olimit, session.handle));
  check(hal_xdr_encode_int(&optr, olimit, kekek.handle));
  check(hal_xdr_encode_variable_opaque(&optr, olimit, pkcs8, pkcs8_len));
  check(hal_xdr_encode_variable_opaque(&optr, olimit, kek, kek_len));
  check(hal_xdr_encode_int(&optr, olimit, flags));
  check(hal_rpc_send(outbuf, optr - outbuf));

  check(read_matching_packet(RPC_FUNC_PKEY_IMPORT, inbuf, sizeof(inbuf), &iptr, &ilimit));

  check(hal_xdr_decode_int(&iptr, ilimit, &rpc_ret));

  if (rpc_ret == HAL_OK) {
    check(hal_xdr_decode_int(&iptr, ilimit, &pkey->handle));
    check(hal_xdr_decode_variable_opaque(&iptr, ilimit, name->uuid, &name_len));
    if (name_len != sizeof(name->uuid))
      return HAL_ERROR_KEY_NAME_TOO_LONG;
  }

  return rpc_ret;
}

#if RPC_CLIENT == RPC_CLIENT_MIXED

/*
 * "Mixed" mode pkey operations, where the public key operation itself
 * takes place on the HSM but the hashing takes place locally.  If
 * we're given a hash context in this case, it's local, so we have to
 * pull the digest from the hash context and send that to the HSM.
 */

static hal_error_t pkey_mixed_sign(const hal_pkey_handle_t pkey,
                                   const hal_hash_handle_t hash,
                                   const uint8_t * const input,  const size_t input_len,
                                   uint8_t * signature, size_t *signature_len, const size_t signature_max)
{
  if (input != NULL)
    return hal_rpc_remote_pkey_dispatch.sign(pkey, hash, input, input_len,
                                             signature, signature_len, signature_max);

  hal_digest_algorithm_t alg;
  hal_key_type_t pkey_type;
  size_t digest_len;
  hal_error_t err;

  if ((err = hal_rpc_hash_get_algorithm(hash, &alg))           != HAL_OK ||
      (err = hal_rpc_hash_get_digest_length(alg, &digest_len)) != HAL_OK ||
      (err = hal_rpc_pkey_get_key_type(pkey, &pkey_type))      != HAL_OK)
    return err;

  uint8_t digest[digest_len > signature_max ? digest_len : signature_max];

  switch (pkey_type) {

  case HAL_KEY_TYPE_RSA_PRIVATE:
  case HAL_KEY_TYPE_RSA_PUBLIC:
    if ((err = hal_rpc_pkcs1_construct_digestinfo(hash, digest, &digest_len, sizeof(digest))) != HAL_OK)
      return err;
    break;

  default:
    if ((err = hal_rpc_hash_finalize(hash, digest, digest_len)) != HAL_OK)
      return err;

  }

  return hal_rpc_remote_pkey_dispatch.sign(pkey, hal_hash_handle_none, digest, digest_len,
                                           signature, signature_len, signature_max);
}

static hal_error_t pkey_mixed_verify(const hal_pkey_handle_t pkey,
                                     const hal_hash_handle_t hash,
                                     const uint8_t * const input, const size_t input_len,
                                     const uint8_t * const signature, const size_t signature_len)
{
  if (input != NULL)
    return hal_rpc_remote_pkey_dispatch.verify(pkey, hash, input, input_len,
                                               signature, signature_len);

  hal_digest_algorithm_t alg;
  hal_key_type_t pkey_type;
  size_t digest_len;
  hal_error_t err;

  if ((err = hal_rpc_hash_get_algorithm(hash, &alg))           != HAL_OK ||
      (err = hal_rpc_hash_get_digest_length(alg, &digest_len)) != HAL_OK ||
      (err = hal_rpc_pkey_get_key_type(pkey, &pkey_type))      != HAL_OK)
    return err;

  uint8_t digest[digest_len > signature_len ? digest_len : signature_len];

  switch (pkey_type) {

  case HAL_KEY_TYPE_RSA_PRIVATE:
  case HAL_KEY_TYPE_RSA_PUBLIC:
    if ((err = hal_rpc_pkcs1_construct_digestinfo(hash, digest, &digest_len, sizeof(digest))) != HAL_OK)
      return err;
    break;

  default:
    if ((err = hal_rpc_hash_finalize(hash, digest, digest_len)) != HAL_OK)
      return err;

  }

  return hal_rpc_remote_pkey_dispatch.verify(pkey, hal_hash_handle_none,
                                             digest, digest_len, signature, signature_len);
}

#endif /* RPC_CLIENT == RPC_CLIENT_MIXED */

/*
 * Dispatch vectors.
 */

const hal_rpc_misc_dispatch_t hal_rpc_remote_misc_dispatch = {
  .set_pin                      = set_pin,
  .login                        = login,
  .logout                       = logout,
  .logout_all                   = logout_all,
  .is_logged_in                 = is_logged_in,
  .get_random                   = get_random,
  .get_version                  = get_version
};

const hal_rpc_hash_dispatch_t hal_rpc_remote_hash_dispatch = {
  .get_digest_length            = hash_get_digest_len,
  .get_digest_algorithm_id      = hash_get_digest_algorithm_id,
  .get_algorithm                = hash_get_algorithm,
  .initialize                   = hash_initialize,
  .update                       = hash_update,
  .finalize                     = hash_finalize
};

const hal_rpc_pkey_dispatch_t hal_rpc_remote_pkey_dispatch = {
  .load                         = pkey_remote_load,
  .open                         = pkey_remote_open,
  .generate_rsa                 = pkey_remote_generate_rsa,
  .generate_ec                  = pkey_remote_generate_ec,
  .generate_hashsig             = pkey_remote_generate_hashsig,
  .close                        = pkey_remote_close,
  .delete                       = pkey_remote_delete,
  .get_key_type                 = pkey_remote_get_key_type,
  .get_key_curve                = pkey_remote_get_key_curve,
  .get_key_flags                = pkey_remote_get_key_flags,
  .get_public_key_len           = pkey_remote_get_public_key_len,
  .get_public_key               = pkey_remote_get_public_key,
  .sign                         = pkey_remote_sign,
  .verify                       = pkey_remote_verify,
  .match                        = pkey_remote_match,
  .set_attributes               = pkey_remote_set_attributes,
  .get_attributes               = pkey_remote_get_attributes,
  .export                       = pkey_remote_export,
  .import                       = pkey_remote_import
};

#if RPC_CLIENT == RPC_CLIENT_MIXED
const hal_rpc_pkey_dispatch_t hal_rpc_mixed_pkey_dispatch = {
  .load                         = pkey_remote_load,
  .open                         = pkey_remote_open,
  .generate_rsa                 = pkey_remote_generate_rsa,
  .generate_ec                  = pkey_remote_generate_ec,
  .generate_hashsig             = pkey_remote_generate_hashsig,
  .close                        = pkey_remote_close,
  .delete                       = pkey_remote_delete,
  .get_key_type                 = pkey_remote_get_key_type,
  .get_key_curve                = pkey_remote_get_key_curve,
  .get_key_flags                = pkey_remote_get_key_flags,
  .get_public_key_len           = pkey_remote_get_public_key_len,
  .get_public_key               = pkey_remote_get_public_key,
  .sign                         = pkey_mixed_sign,
  .verify                       = pkey_mixed_verify,
  .match                        = pkey_remote_match,
  .set_attributes               = pkey_remote_set_attributes,
  .get_attributes               = pkey_remote_get_attributes,
  .export                       = pkey_remote_export,
  .import                       = pkey_remote_import
};
#endif /* RPC_CLIENT == RPC_CLIENT_MIXED */

#endif /* RPC_CLIENT != RPC_CLIENT_LOCAL */


#if RPC_CLIENT == RPC_CLIENT_REMOTE
const hal_rpc_misc_dispatch_t * hal_rpc_misc_dispatch = &hal_rpc_remote_misc_dispatch;
const hal_rpc_hash_dispatch_t * hal_rpc_hash_dispatch = &hal_rpc_remote_hash_dispatch;
const hal_rpc_pkey_dispatch_t * hal_rpc_pkey_dispatch = &hal_rpc_remote_pkey_dispatch;
#endif

#if RPC_CLIENT == RPC_CLIENT_MIXED
const hal_rpc_misc_dispatch_t * hal_rpc_misc_dispatch = &hal_rpc_remote_misc_dispatch;
const hal_rpc_hash_dispatch_t * hal_rpc_hash_dispatch = &hal_rpc_local_hash_dispatch;
const hal_rpc_pkey_dispatch_t * hal_rpc_pkey_dispatch = &hal_rpc_mixed_pkey_dispatch;
#endif

hal_error_t hal_rpc_client_init(void)
{
#if RPC_CLIENT == RPC_CLIENT_LOCAL
  return HAL_OK;
#else
  return hal_rpc_client_transport_init();
#endif
}

hal_error_t hal_rpc_client_close(void)
{
#if RPC_CLIENT == RPC_CLIENT_LOCAL
  return HAL_OK;
#else
  return hal_rpc_client_transport_close();
#endif
}

/*
 * Local variables:
 * indent-tabs-mode: nil
 * End:
 */