diff options
Diffstat (limited to 'plugins/sudoers/sudo_nss.c')
-rw-r--r-- | plugins/sudoers/sudo_nss.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/plugins/sudoers/sudo_nss.c b/plugins/sudoers/sudo_nss.c new file mode 100644 index 0000000..a48bb67 --- /dev/null +++ b/plugins/sudoers/sudo_nss.c @@ -0,0 +1,264 @@ +/* + * SPDX-License-Identifier: ISC + * + * Copyright (c) 2007-2015 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. + */ + +/* + * 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 <stdio.h> +#include <stdlib.h> +#include <string.h> +#ifdef HAVE_STRINGS_H +# include <strings.h> +#endif /* HAVE_STRINGS_H */ +#include <ctype.h> + +#include "sudoers.h" + +extern struct sudo_nss sudo_nss_file; +#ifdef HAVE_LDAP +extern struct sudo_nss sudo_nss_ldap; +#endif +#ifdef HAVE_SSSD +extern struct sudo_nss sudo_nss_sss; +#endif + +/* Make sure we have not already inserted the nss entry. */ +#define SUDO_NSS_CHECK_UNUSED(nss, tag) \ + if (nss.entries.tqe_next != NULL || nss.entries.tqe_prev != NULL) { \ + sudo_warnx("internal error: nsswitch entry \"%s\" already in use", \ + tag); \ + continue; \ + } + +#if (defined(HAVE_LDAP) || defined(HAVE_SSSD)) && defined(_PATH_NSSWITCH_CONF) +/* + * Read in /etc/nsswitch.conf + * Returns a tail queue of matches. + */ +struct sudo_nss_list * +sudo_read_nss(void) +{ + FILE *fp; + char *line = NULL; + size_t linesize = 0; +#ifdef HAVE_SSSD + bool saw_sss = false; +#endif +#ifdef HAVE_LDAP + bool saw_ldap = false; +#endif + bool saw_files = false; + bool got_match = false; + static struct sudo_nss_list snl = TAILQ_HEAD_INITIALIZER(snl); + debug_decl(sudo_read_nss, SUDOERS_DEBUG_NSS); + + if ((fp = fopen(_PATH_NSSWITCH_CONF, "r")) == NULL) + goto nomatch; + + while (sudo_parseln(&line, &linesize, NULL, fp, 0) != -1) { + char *cp, *last; + + /* Skip blank or comment lines */ + if (*line == '\0') + continue; + + /* Look for a line starting with "sudoers:" */ + if (strncasecmp(line, "sudoers:", 8) != 0) + continue; + + /* Parse line */ + for ((cp = strtok_r(line + 8, " \t", &last)); cp != NULL; (cp = strtok_r(NULL, " \t", &last))) { + if (strcasecmp(cp, "files") == 0 && !saw_files) { + SUDO_NSS_CHECK_UNUSED(sudo_nss_file, "files"); + TAILQ_INSERT_TAIL(&snl, &sudo_nss_file, entries); + got_match = saw_files = true; +#ifdef HAVE_LDAP + } else if (strcasecmp(cp, "ldap") == 0 && !saw_ldap) { + SUDO_NSS_CHECK_UNUSED(sudo_nss_ldap, "ldap"); + TAILQ_INSERT_TAIL(&snl, &sudo_nss_ldap, entries); + got_match = saw_ldap = true; +#endif +#ifdef HAVE_SSSD + } else if (strcasecmp(cp, "sss") == 0 && !saw_sss) { + SUDO_NSS_CHECK_UNUSED(sudo_nss_sss, "sss"); + TAILQ_INSERT_TAIL(&snl, &sudo_nss_sss, entries); + got_match = saw_sss = true; +#endif + } else if (strcasecmp(cp, "[NOTFOUND=return]") == 0 && got_match) { + /* NOTFOUND affects the most recent entry */ + TAILQ_LAST(&snl, sudo_nss_list)->ret_if_notfound = true; + got_match = false; + } else if (strcasecmp(cp, "[SUCCESS=return]") == 0 && got_match) { + /* SUCCESS affects the most recent entry */ + TAILQ_LAST(&snl, sudo_nss_list)->ret_if_found = true; + got_match = false; + } else + got_match = false; + } + /* Only parse the first "sudoers:" line */ + break; + } + free(line); + fclose(fp); + +nomatch: + /* Default to files only if no matches */ + if (TAILQ_EMPTY(&snl)) + TAILQ_INSERT_TAIL(&snl, &sudo_nss_file, entries); + + debug_return_ptr(&snl); +} + +#else /* (HAVE_LDAP || HAVE_SSSD) && _PATH_NSSWITCH_CONF */ + +# if (defined(HAVE_LDAP) || defined(HAVE_SSSD)) && defined(_PATH_NETSVC_CONF) + +/* + * Read in /etc/netsvc.conf (like nsswitch.conf on AIX) + * Returns a tail queue of matches. + */ +struct sudo_nss_list * +sudo_read_nss(void) +{ + FILE *fp; + char *cp, *ep, *last, *line = NULL; + size_t linesize = 0; +#ifdef HAVE_SSSD + bool saw_sss = false; +#endif + bool saw_files = false; + bool saw_ldap = false; + bool got_match = false; + static struct sudo_nss_list snl = TAILQ_HEAD_INITIALIZER(snl); + debug_decl(sudo_read_nss, SUDOERS_DEBUG_NSS); + + if ((fp = fopen(_PATH_NETSVC_CONF, "r")) == NULL) + goto nomatch; + + while (sudo_parseln(&line, &linesize, NULL, fp, 0) != -1) { + /* Skip blank or comment lines */ + if (*(cp = line) == '\0') + continue; + + /* Look for a line starting with "sudoers = " */ + if (strncasecmp(cp, "sudoers", 7) != 0) + continue; + cp += 7; + while (isspace((unsigned char)*cp)) + cp++; + if (*cp++ != '=') + continue; + + /* Parse line */ + for ((cp = strtok_r(cp, ",", &last)); cp != NULL; (cp = strtok_r(NULL, ",", &last))) { + /* Trim leading whitespace. */ + while (isspace((unsigned char)*cp)) + cp++; + + if (!saw_files && strncasecmp(cp, "files", 5) == 0 && + (isspace((unsigned char)cp[5]) || cp[5] == '\0')) { + TAILQ_INSERT_TAIL(&snl, &sudo_nss_file, entries); + got_match = saw_files = true; + ep = &cp[5]; +#ifdef HAVE_LDAP + } else if (!saw_ldap && strncasecmp(cp, "ldap", 4) == 0 && + (isspace((unsigned char)cp[4]) || cp[4] == '\0')) { + TAILQ_INSERT_TAIL(&snl, &sudo_nss_ldap, entries); + got_match = saw_ldap = true; + ep = &cp[4]; +#endif +#ifdef HAVE_SSSD + } else if (!saw_sss && strncasecmp(cp, "sss", 3) == 0 && + (isspace((unsigned char)cp[3]) || cp[3] == '\0')) { + TAILQ_INSERT_TAIL(&snl, &sudo_nss_sss, entries); + got_match = saw_sss = true; + ep = &cp[3]; +#endif + } else { + got_match = false; + } + + /* check for = auth qualifier */ + if (got_match && *ep) { + cp = ep; + while (isspace((unsigned char)*cp) || *cp == '=') + cp++; + if (strncasecmp(cp, "auth", 4) == 0 && + (isspace((unsigned char)cp[4]) || cp[4] == '\0')) { + TAILQ_LAST(&snl, sudo_nss_list)->ret_if_found = true; + } + } + } + /* Only parse the first "sudoers" line */ + break; + } + fclose(fp); + +nomatch: + /* Default to files only if no matches */ + if (TAILQ_EMPTY(&snl)) + TAILQ_INSERT_TAIL(&snl, &sudo_nss_file, entries); + + debug_return_ptr(&snl); +} + +# else /* !_PATH_NETSVC_CONF && !_PATH_NSSWITCH_CONF */ + +/* + * Non-nsswitch.conf version with hard-coded order. + */ +struct sudo_nss_list * +sudo_read_nss(void) +{ + static struct sudo_nss_list snl = TAILQ_HEAD_INITIALIZER(snl); + debug_decl(sudo_read_nss, SUDOERS_DEBUG_NSS); + +# ifdef HAVE_SSSD + TAILQ_INSERT_TAIL(&snl, &sudo_nss_sss, entries); +# endif +# ifdef HAVE_LDAP + TAILQ_INSERT_TAIL(&snl, &sudo_nss_ldap, entries); +# endif + TAILQ_INSERT_TAIL(&snl, &sudo_nss_file, entries); + + debug_return_ptr(&snl); +} + +# endif /* !HAVE_LDAP || !_PATH_NETSVC_CONF */ + +#endif /* HAVE_LDAP && _PATH_NSSWITCH_CONF */ + +bool +sudo_nss_can_continue(struct sudo_nss *nss, int match) +{ + debug_decl(sudo_nss_should_continue, SUDOERS_DEBUG_NSS); + + /* Handle [NOTFOUND=return] */ + if (nss->ret_if_notfound && match == UNSPEC) + debug_return_bool(false); + + /* Handle [SUCCESS=return] */ + if (nss->ret_if_found && match != UNSPEC) + debug_return_bool(false); + + debug_return_bool(true); +} |