/*  $OpenBSD: sshbuf-io.c,v 1.2 2020/01/25 23:28:06 djm Exp $ */

/*

 * Copyright (c) 2011 Damien Miller

 *

 * Permission to use, copy, modify, and distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 */

#include "includes.h"

#include <sys/types.h>

#include <sys/stat.h>

#include <errno.h>

#include <fcntl.h>

#include <unistd.h>

#include <string.h>

#include "ssherr.h"

#include "sshbuf.h"

#include "atomicio.h"

/* Load a file from a fd into a buffer */

int

sshbuf_load_fd(int fd, struct sshbuf **blobp)

{

  u_char buf[4096];

  size_t len;

  struct stat st;

  int r;

  struct sshbuf *blob;

  *blobp = NULL;

  if (fstat(fd, &st) == -1)

    return SSH_ERR_SYSTEM_ERROR;

  if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&

      st.st_size > SSHBUF_SIZE_MAX)

    return SSH_ERR_INVALID_FORMAT;

  if ((blob = sshbuf_new()) == NULL)

    return SSH_ERR_ALLOC_FAIL;

  for (;;) {

    if ((len = atomicio(read, fd, buf, sizeof(buf))) == 0) {

      if (errno == EPIPE)

        break;

      r = SSH_ERR_SYSTEM_ERROR;

      goto out;

    }

    if ((r = sshbuf_put(blob, buf, len)) != 0)

      goto out;

    if (sshbuf_len(blob) > SSHBUF_SIZE_MAX) {

      r = SSH_ERR_INVALID_FORMAT;

      goto out;

    }

  }

  if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&

      st.st_size != (off_t)sshbuf_len(blob)) {

    r = SSH_ERR_FILE_CHANGED;

    goto out;

  }

  /* success */

  *blobp = blob;

  blob = NULL; /* transferred */

  r = 0;

 out:

  explicit_bzero(buf, sizeof(buf));

  sshbuf_free(blob);

  return r;

}

int

sshbuf_load_file(const char *path, struct sshbuf **bufp)

{

  int r, fd, oerrno;

  *bufp = NULL;

  if ((fd = open(path, O_RDONLY)) == -1)

    return SSH_ERR_SYSTEM_ERROR;

  if ((r = sshbuf_load_fd(fd, bufp)) != 0)

    goto out;

  /* success */

  r = 0;

 out:

  oerrno = errno;

  close(fd);

  if (r != 0)

    errno = oerrno;

  return r;

}

int

sshbuf_write_file(const char *path, struct sshbuf *buf)

{

  int fd, oerrno;

  if ((fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644)) == -1)

    return SSH_ERR_SYSTEM_ERROR;

  if (atomicio(vwrite, fd, sshbuf_mutable_ptr(buf),

      sshbuf_len(buf)) != sshbuf_len(buf) || close(fd) != 0) {

    oerrno = errno;

    close(fd);

    unlink(path);

    errno = oerrno;

    return SSH_ERR_SYSTEM_ERROR;

  }

  return 0;

}