/*

 * Copyright (c) 2006 Kungliga Tekniska Högskolan

 * (Royal Institute of Technology, Stockholm, Sweden).

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 *

 * 2. 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.

 *

 * 3. Neither the name of the Institute 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 INSTITUTE 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 INSTITUTE 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 <config.h>

#include <roken.h>

#include <rand.h>

#include <heim_threads.h>

#include "randi.h"

/*

 * Unix /dev/random

 */

int

_hc_unix_device_fd(int flags, const char **fn)

{

    static const char *rnd_devices[] = {

  "/dev/urandom",

  "/dev/random",

  "/dev/srandom",

  "/dev/arandom",

  NULL

    };

    const char **p;

    for(p = rnd_devices; *p; p++) {

  int fd = open(*p, flags | O_NDELAY);

  if(fd >= 0) {

      if (fn)

    *fn = *p;

      rk_cloexec(fd);

      return fd;

  }

    }

    return -1;

}

static void

unix_seed(const void *p, int size)

{

    const unsigned char *indata = p;

    ssize_t count;

    int fd;

    if (size < 0)

  return;

    else if (size == 0)

  return;

    fd = _hc_unix_device_fd(O_RDONLY, NULL);

    if (fd < 0)

  return;

    while (size > 0) {

  count = write(fd, indata, size);

  if (count < 0 && errno == EINTR)

      continue;

  else if (count <= 0) {

      close(fd);

      return;

  }

  indata += count;

  size -= count;

    }

    close(fd);

}

static int

unix_bytes(unsigned char *outdata, int size)

{

    ssize_t count;

    int fd;

    if (size < 0)

  return 0;

    else if (size == 0)

  return 1;

    fd = _hc_unix_device_fd(O_RDONLY, NULL);

    if (fd < 0)

  return 0;

    while (size > 0) {

  count = read(fd, outdata, size);

  if (count < 0 && errno == EINTR)

      continue;

  else if (count <= 0) {

      close(fd);

      return 0;

  }

  outdata += count;

  size -= count;

    }

    close(fd);

    return 1;

}

static void

unix_cleanup(void)

{

}

static void

unix_add(const void *indata, int size, double entropi)

{

    unix_seed(indata, size);

}

static int

unix_pseudorand(unsigned char *outdata, int size)

{

    return unix_bytes(outdata, size);

}

static int

unix_status(void)

{

    int fd;

    fd = _hc_unix_device_fd(O_RDONLY, NULL);

    if (fd < 0)

  return 0;

    close(fd);

    return 1;

}

const RAND_METHOD hc_rand_unix_method = {

    unix_seed,

    unix_bytes,

    unix_cleanup,

    unix_add,

    unix_pseudorand,

    unix_status

};

const RAND_METHOD *

RAND_unix_method(void)

{

    return &hc_rand_unix_method;

}