/*

 * SPDX-License-Identifier: ISC

 *

 * Copyright (c) 1996, 1998-2005, 2007-2021, 2023-2025

 *  Todd C. Miller <Todd.Miller@sudo.ws>

 *

 * 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.

 *

 * Sponsored in part by the Defense Advanced Research Projects

 * Agency (DARPA) and Air Force Research Laboratory, Air Force

 * Materiel Command, USAF, under agreement number F39502-99-1-0512.

 */

/*

 * This is an open source non-commercial project. Dear PVS-Studio, please check it.

 * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com

 */

#include <config.h>

#include <stddef.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <errno.h>

#include <limits.h>

#include <pwd.h>

#include <grp.h>

#include <sudoers.h>

#include <pwutil.h>

/*

 * For testsudoers and cvtsudoers need to support building with a different

 * function prefix and using custom getpwnam/getpwuid/getgrnam/getgrgid.

 */

#define EXPAND(p, f)  p ## _ ## f

#define WRAP(p, f)  EXPAND(p, f)

#ifdef PWUTIL_PREFIX

# define CALL(x)  WRAP(PWUTIL_PREFIX, x)

# define PREFIX(x)  WRAP(PWUTIL_PREFIX, x)

#else

# define CALL(x)  x

# define PREFIX(x)  WRAP(sudo, x)

#endif

#define FIELD_SIZE(src, name, size)     \

do {             \

  if (src->name) {       \

    size = strlen(src->name) + 1;   \

    total += size;        \

  } else {                                        \

    size = 0;       \

  }                                               \

} while (0)

#define FIELD_COPY(src, dst, name, size)    \

do {             \

  if (src->name) {       \

    memcpy(cp, src->name, size);    \

    dst->name = cp;       \

    cp += size;       \

  }            \

} while (0)

/*

 * Dynamically allocate space for a struct item plus the key and data

 * elements.  If name is non-NULL it is used as the key, else the

 * uid is the key.  Fills in datum from struct password.

 * Returns NULL on calloc error or unknown name/id, setting errno

 * to ENOMEM or ENOENT respectively.

 */

struct cache_item *

PREFIX(make_pwitem)(uid_t uid, const char *name)

{

    char *cp;

    const char *pw_shell;

    size_t nsize, psize, gsize, dsize, ssize, total;

#ifdef HAVE_LOGIN_CAP_H

    size_t csize;

#endif

    struct cache_item_pw *pwitem;

    struct passwd *pw, *newpw;

    debug_decl(sudo_make_pwitem, SUDOERS_DEBUG_NSS);

    /* Look up by name or uid. */

    pw = name ? CALL(getpwnam)(name) : CALL(getpwuid)(uid);

    if (pw == NULL) {

  errno = ENOENT;

  debug_return_ptr(NULL);

    }

    /* If shell field is empty, expand to _PATH_BSHELL. */

    pw_shell = (pw->pw_shell == NULL || pw->pw_shell[0] == '\0')

  ? _PATH_BSHELL : pw->pw_shell;

    /* Allocate in one big chunk for easy freeing. */

    total = sizeof(*pwitem);

    FIELD_SIZE(pw, pw_name, nsize);

    FIELD_SIZE(pw, pw_passwd, psize);

#ifdef HAVE_LOGIN_CAP_H

    FIELD_SIZE(pw, pw_class, csize);

#endif

    FIELD_SIZE(pw, pw_gecos, gsize);

    FIELD_SIZE(pw, pw_dir, dsize);

    /* Treat shell specially since we expand "" -> _PATH_BSHELL */

    ssize = strlen(pw_shell) + 1;

    total += ssize;

    if (name != NULL)

  total += strlen(name) + 1;

    /* Allocate space for struct item, struct passwd and the strings. */

    if ((pwitem = calloc(1, total)) == NULL) {

  sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,

      "unable to allocate memory");

  debug_return_ptr(NULL);

    }

    newpw = &pwitem->pw;

    /*

     * Copy in passwd contents and make strings relative to space

     * at the end of the struct.

     */

    memcpy(newpw, pw, sizeof(*pw));

    cp = (char *)(pwitem + 1);

    FIELD_COPY(pw, newpw, pw_name, nsize);

    FIELD_COPY(pw, newpw, pw_passwd, psize);

#ifdef HAVE_LOGIN_CAP_H

    FIELD_COPY(pw, newpw, pw_class, csize);

#endif

    FIELD_COPY(pw, newpw, pw_gecos, gsize);

    FIELD_COPY(pw, newpw, pw_dir, dsize);

    /* Treat shell specially since we expand "" -> _PATH_BSHELL */

    memcpy(cp, pw_shell, ssize);

    newpw->pw_shell = cp;

    cp += ssize;

    /* Set key and datum. */

    if (name != NULL) {

  memcpy(cp, name, strlen(name) + 1);

  pwitem->cache.k.name = cp;

    } else {

  pwitem->cache.k.uid = pw->pw_uid;

    }

    pwitem->cache.d.pw = newpw;

    pwitem->cache.refcnt = 1;

    debug_return_ptr(&pwitem->cache);

}

/*

 * Dynamically allocate space for a struct item plus the key and data

 * elements.  If name is non-NULL it is used as the key, else the

 * gid is the key.  Fills in datum from struct group.

 * Returns NULL on calloc error or unknown name/id, setting errno

 * to ENOMEM or ENOENT respectively.

 */

struct cache_item *

PREFIX(make_gritem)(gid_t gid, const char *name)

{

    char *cp;

    size_t nsize, psize, total, len, nmem = 0;

    struct cache_item_gr *gritem;

    struct group *gr, *newgr;

    debug_decl(sudo_make_gritem, SUDOERS_DEBUG_NSS);

    /* Look up by name or gid. */

    gr = name ? CALL(getgrnam)(name) : CALL(getgrgid)(gid);

    if (gr == NULL) {

  errno = ENOENT;

  debug_return_ptr(NULL);

    }

    /* Allocate in one big chunk for easy freeing. */

    total = sizeof(*gritem);

    FIELD_SIZE(gr, gr_name, nsize);

    FIELD_SIZE(gr, gr_passwd, psize);

    if (gr->gr_mem) {

  for (nmem = 0; gr->gr_mem[nmem] != NULL; nmem++)

      total += strlen(gr->gr_mem[nmem]) + 1;

  nmem++;

  total += sizeof(char *) * nmem;

    }

    if (name != NULL)

  total += strlen(name) + 1;

    if ((gritem = calloc(1, total)) == NULL) {

  sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,

      "unable to allocate memory");

  debug_return_ptr(NULL);

    }

    /*

     * Copy in group contents and make strings relative to space

     * at the end of the buffer.  Note that gr_mem must come

     * immediately after struct group to guarantee proper alignment.

     */

    newgr = &gritem->gr;

    memcpy(newgr, gr, sizeof(*gr));

    cp = (char *)(gritem + 1);

    if (gr->gr_mem) {

  newgr->gr_mem = (char **)cp;

  cp += sizeof(char *) * nmem;

  for (nmem = 0; gr->gr_mem[nmem] != NULL; nmem++) {

      len = strlen(gr->gr_mem[nmem]) + 1;

      memcpy(cp, gr->gr_mem[nmem], len);

      newgr->gr_mem[nmem] = cp;

      cp += len;

  }

  newgr->gr_mem[nmem] = NULL;

    }

    FIELD_COPY(gr, newgr, gr_passwd, psize);

    FIELD_COPY(gr, newgr, gr_name, nsize);

    /* Set key and datum. */

    if (name != NULL) {

  memcpy(cp, name, strlen(name) + 1);

  gritem->cache.k.name = cp;

    } else {

  gritem->cache.k.gid = gr->gr_gid;

    }

    gritem->cache.d.gr = newgr;

    gritem->cache.refcnt = 1;

    debug_return_ptr(&gritem->cache);

}

/*

 * Dynamically allocate space for a struct item plus the key and data elements.

 */

struct cache_item *

PREFIX(make_gidlist_item)(const struct passwd *pw, int ngids, GETGROUPS_T *gids,

    char * const *gidstrs, unsigned int type)

{

    char *cp;

    size_t nsize, total;

    struct cache_item_gidlist *glitem;

    struct gid_list *gidlist;

    int i;

    debug_decl(sudo_make_gidlist_item, SUDOERS_DEBUG_NSS);

    /*

     * Ignore supplied gids if the entry type says we must query the group db.

     */

    if (type != ENTRY_TYPE_QUERIED && (gids != NULL || gidstrs != NULL)) {

  if (gids == NULL) {

      /* Convert the supplied gids list from string format to gid_t. */

      ngids = 1;

      for (i = 0; gidstrs[i] != NULL; i++)

    ngids++;

      gids = reallocarray(NULL, (size_t)ngids, sizeof(GETGROUPS_T));

      if (gids == NULL) {

    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,

        "unable to allocate memory");

    debug_return_ptr(NULL);

      }

      ngids = 1;

      gids[0] = pw->pw_gid;

      for (i = 0; gidstrs[i] != NULL; i++) {

    const char *errstr;

    GETGROUPS_T gid = (gid_t) sudo_strtoid(gidstrs[i], &errstr);

    if (errstr != NULL) {

        sudo_debug_printf(SUDO_DEBUG_DIAG|SUDO_DEBUG_LINENO,

      "gid %s %s", gidstrs[i], errstr);

        continue;

    }

    if (gid != gids[0])

        gids[ngids++] = gid;

      }

  }

  type = ENTRY_TYPE_FRONTEND;

    } else {

  type = ENTRY_TYPE_QUERIED;

  ngids = sudo_pwutil_get_max_groups();

  if (ngids > 0) {

      gids = reallocarray(NULL, (size_t)ngids, sizeof(GETGROUPS_T));

      if (gids == NULL) {

    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,

        "unable to allocate memory");

    debug_return_ptr(NULL);

      }

      /* Clamp to max_groups if insufficient space for all groups. */

      if (PREFIX(getgrouplist2)(pw->pw_name, pw->pw_gid, &gids, &ngids) == -1)

    ngids = sudo_pwutil_get_max_groups();

  } else {

      gids = NULL;

      if (PREFIX(getgrouplist2)(pw->pw_name, pw->pw_gid, &gids, &ngids) == -1) {

    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,

        "unable to allocate memory");

    debug_return_ptr(NULL);

      }

  }

    }

    if (ngids <= 0) {

  free(gids);

  errno = ENOENT;

  debug_return_ptr(NULL);

    }

    /* Allocate in one big chunk for easy freeing. */

    nsize = strlen(pw->pw_name) + 1;

    total = sizeof(*glitem) + nsize;

    total += sizeof(gid_t *) * (size_t)ngids;

    if ((glitem = calloc(1, total)) == NULL) {

  sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,

      "unable to allocate memory");

  free(gids);

  debug_return_ptr(NULL);

    }

    /*

     * Copy in group list and make pointers relative to space

     * at the end of the buffer.  Note that the groups array must come

     * immediately after struct group to guarantee proper alignment.

     */

    gidlist = &glitem->gidlist;

    cp = (char *)(glitem + 1);

    gidlist->gids = (gid_t *)cp;

    cp += sizeof(gid_t) * (size_t)ngids;

    /* Set key and datum. */

    memcpy(cp, pw->pw_name, nsize);

    glitem->cache.k.name = cp;

    glitem->cache.d.gidlist = gidlist;

    glitem->cache.refcnt = 1;

    glitem->cache.type = type;

    /*

     * Store group IDs.

     */

    for (i = 0; i < ngids; i++)

  gidlist->gids[i] = gids[i];

    gidlist->ngids = ngids;

    free(gids);

    debug_return_ptr(&glitem->cache);

}

/*

 * Dynamically allocate space for a struct item plus the key and data

 * elements.  Fills in group names from a call to sudo_get_gidlist().

 */

struct cache_item *

PREFIX(make_grlist_item)(const struct passwd *pw, char * const *unused1)

{

    const size_t groupname_len = sudo_login_name_max();

    size_t len, ngroups, nsize, total;

    struct cache_item_grlist *grlitem;

    struct group_list *grlist;

    struct gid_list *gidlist;

    struct group *grp = NULL;

    char *cp;

    int i;

    debug_decl(sudo_make_grlist_item, SUDOERS_DEBUG_NSS);

    gidlist = sudo_get_gidlist(pw, ENTRY_TYPE_ANY);

    if (gidlist == NULL) {

  sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,

      "no gid list for use %s", pw->pw_name);

  errno = ENOENT;

  debug_return_ptr(NULL);

    }

    /* Allocate in one big chunk for easy freeing. */

    nsize = strlen(pw->pw_name) + 1;

    total = sizeof(*grlitem) + nsize;

    total += sizeof(char *) * (size_t)gidlist->ngids;

    total += groupname_len * (size_t)gidlist->ngids;

again:

    if ((grlitem = calloc(1, total)) == NULL) {

  sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,

      "unable to allocate memory");

  sudo_gidlist_delref(gidlist);

  debug_return_ptr(NULL);

    }

    /*

     * Copy in group list and make pointers relative to space

     * at the end of the buffer.  Note that the groups array must come

     * immediately after struct group to guarantee proper alignment.

     */

    grlist = &grlitem->grlist;

    cp = (char *)(grlitem + 1);

    grlist->groups = (char **)cp;

    cp += sizeof(char *) * (size_t)gidlist->ngids;

    /* Set key and datum. */

    memcpy(cp, pw->pw_name, nsize);

    grlitem->cache.k.name = cp;

    grlitem->cache.d.grlist = grlist;

    grlitem->cache.refcnt = 1;

    cp += nsize;

    /*

     * Resolve and store group names by ID.

     */

#ifdef HAVE_SETAUTHDB

    if (grp == NULL)

  aix_setauthdb((char *) pw->pw_name, NULL);

#endif

    ngroups = 0;

    for (i = 0; i < gidlist->ngids; i++) {

  if ((grp = sudo_getgrgid(gidlist->gids[i])) != NULL) {

      len = strlen(grp->gr_name) + 1;

      if ((size_t)(cp - (char *)grlitem) + len > total) {

    total += len + groupname_len;

    free(grlitem);

    sudo_gr_delref(grp);

    goto again;

      }

      memcpy(cp, grp->gr_name, len);

      grlist->groups[ngroups++] = cp;

      cp += len;

      sudo_gr_delref(grp);

  }

    }

    grlist->ngroups = (int)ngroups;

    sudo_gidlist_delref(gidlist);

#ifdef HAVE_SETAUTHDB

    aix_restoreauthdb();

#endif

    debug_return_ptr(&grlitem->cache);

}

/*

 * Returns true if the specified shell is allowed by /etc/shells, else false.

 */

bool

PREFIX(valid_shell)(const char *shell)

{

    const char *entry;

    debug_decl(valid_shell, SUDOERS_DEBUG_NSS);

    sudo_debug_printf(SUDO_DEBUG_INFO,

  "%s: checking /etc/shells for %s", __func__, shell);

    CALL(setusershell)();

    while ((entry = CALL(getusershell)()) != NULL) {

  if (strcmp(entry, shell) == 0)

      debug_return_bool(true);

    }

    CALL(endusershell)();

    debug_return_bool(false);

}