Files
sudo/plugins/sudoers/ldap_common.c
2018-02-09 18:21:40 -07:00

429 lines
11 KiB
C

/*
* Copyright (c) 2013, 2016, 2018 Todd C. Miller <Todd.Miller@sudo.ws>
*
* This code is derived from software contributed by Aaron Spangler.
*
* 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 <config.h>
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#ifdef HAVE_STRING_H
# include <string.h>
#endif /* HAVE_STRING_H */
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif /* HAVE_STRINGS_H */
#include <ctype.h>
#ifdef HAVE_LBER_H
# include <lber.h>
#endif
#include <ldap.h>
#include "sudoers.h"
#include "parse.h"
#include "gram.h"
#include "sudo_lbuf.h"
#include "sudo_ldap.h"
/*
* Returns true if the string pointed to by valp begins with an
* odd number of '!' characters. Intervening blanks are ignored.
* Stores the address of the string after '!' removal in valp.
*/
bool
sudo_ldap_is_negated(char **valp)
{
char *val = *valp;
bool ret = false;
debug_decl(sudo_ldap_is_negated, SUDOERS_DEBUG_LDAP)
while (*val == '!') {
ret = !ret;
do {
val++;
} while (isblank((unsigned char)*val));
}
*valp = val;
debug_return_bool(ret);
}
/*
* Parse an option string into a defaults structure.
* The members of def are pointers into optstr (which is modified).
*/
int
sudo_ldap_parse_option(char *optstr, char **varp, char **valp)
{
char *cp, *val = NULL;
char *var = optstr;
int op;
debug_decl(sudo_ldap_parse_option, SUDOERS_DEBUG_LDAP)
/* check for equals sign past first char */
cp = strchr(var, '=');
if (cp > var) {
val = cp + 1;
op = cp[-1]; /* peek for += or -= cases */
if (op == '+' || op == '-') {
/* case var+=val or var-=val */
cp--;
} else {
/* case var=val */
op = true;
}
/* Trim whitespace between var and operator. */
while (cp > var && isblank((unsigned char)cp[-1]))
cp--;
/* Truncate variable name. */
*cp = '\0';
/* Trim leading whitespace from val. */
while (isblank((unsigned char)*val))
val++;
/* Strip double quotes if present. */
if (*val == '"') {
char *ep = val + strlen(val);
if (ep != val && ep[-1] == '"') {
val++;
ep[-1] = '\0';
}
}
} else {
/* Boolean value, either true or false. */
op = sudo_ldap_is_negated(&var) ? false : true;
}
*varp = var;
*valp = val;
debug_return_int(op);
}
/*
* Convert an array to a member list.
* The caller is responsible for freeing the returned struct member_list.
*/
static struct member_list *
array_to_member_list(void *a, size_t ele_size, size_t str_off)
{
struct member_list *members;
struct member *m;
debug_decl(bv_to_member_list, SUDOERS_DEBUG_LDAP)
if ((members = calloc(1, sizeof(*members))) == NULL)
return NULL;
TAILQ_INIT(members);
for (;*((char **)a) != NULL; a = (char *)a + ele_size) {
char *val = *(char **)(*((char **)a) + str_off);
if ((m = calloc(1, sizeof(*m))) == NULL)
goto bad;
switch (val[0]) {
case '\0':
/* Empty RunAsUser means run as the invoking user. */
m->type = MYSELF;
break;
case 'A':
if (strcmp(val, "ALL") == 0) {
m->type = ALL;
break;
}
/* FALLTHROUGH */
default:
m->type = WORD;
m->name = strdup(val);
if (m->name == NULL) {
free(m);
goto bad;
}
break;
}
TAILQ_INSERT_TAIL(members, m, entries);
}
debug_return_ptr(members);
bad:
while ((m = TAILQ_FIRST(members)) != NULL) {
TAILQ_REMOVE(members, m, entries);
free(m->name);
free(m);
}
free(members);
debug_return_ptr(NULL);
}
/*
* Convert an LDAP sudoRole to a sudoers privilege.
* Pass in struct berval ** for LDAP or char *** for SSSD.
*/
struct privilege *
sudo_ldap_role_to_priv(const char *cn, void *runasusers, void *runasgroups,
void *cmnds, void *opts, const char *notbefore,
const char *notafter, size_t ele_size, size_t str_off)
{
struct cmndspec *cmndspec = NULL;
struct cmndspec *prev_cmndspec = NULL;
struct sudo_command *c;
struct privilege *priv;
struct member *m;
debug_decl(sudo_ldap_role_to_priv, SUDOERS_DEBUG_LDAP)
if ((priv = calloc(1, sizeof(*priv))) == NULL)
goto oom;
TAILQ_INIT(&priv->hostlist);
TAILQ_INIT(&priv->cmndlist);
TAILQ_INIT(&priv->defaults);
priv->ldap_role = strdup(cn ? cn : "UNKNOWN");
if (priv->ldap_role == NULL)
goto oom;
/* The host has already matched, use ALL as wildcard. */
if ((m = calloc(1, sizeof(*m))) == NULL)
goto oom;
m->type = ALL;
TAILQ_INSERT_TAIL(&priv->hostlist, m, entries);
/*
* Parse sudoCommands and add to cmndlist.
* The convoluted pointer arithmetic is to support passing in
* either a struct berval ** or a char ***.
* An interator would probably be better.
*/
for (;*((char **)cmnds) != NULL; cmnds = (char *)cmnds + ele_size) {
char *cmnd = *(char **)(*((char **)cmnds) + str_off);
char *args;
/* Allocate storage upfront. */
cmndspec = calloc(1, sizeof(*cmndspec));
c = calloc(1, sizeof(*c));
m = calloc(1, sizeof(*m));
if (cmndspec == NULL || c == NULL || m == NULL) {
free(cmndspec);
free(c);
free(m);
goto oom;
}
TAILQ_INSERT_TAIL(&priv->cmndlist, cmndspec, entries);
/* Initialize cmndspec */
TAGS_INIT(cmndspec->tags);
cmndspec->notbefore = UNSPEC;
cmndspec->notafter = UNSPEC;
cmndspec->timeout = UNSPEC;
/* Fill in command. */
if ((args = strpbrk(cmnd, " \t")) != NULL) {
*args++ = '\0';
if ((c->args = strdup(args)) == NULL) {
free(c);
free(m);
goto oom;
}
}
if ((c->cmnd = strdup(cmnd)) == NULL) {
free(c->args);
free(c);
free(m);
goto oom;
}
m->type = COMMAND;
m->name = (char *)c;
cmndspec->cmnd = m;
if (prev_cmndspec != NULL) {
/* Inherit values from prior cmndspec */
cmndspec->runasuserlist = prev_cmndspec->runasuserlist;
cmndspec->runasgrouplist = prev_cmndspec->runasgrouplist;
cmndspec->notbefore = prev_cmndspec->notbefore;
cmndspec->notafter = prev_cmndspec->notafter;
cmndspec->tags = prev_cmndspec->tags;
} else {
/* Parse sudoRunAsUser / sudoRunAs */
if (runasusers != NULL) {
cmndspec->runasuserlist =
array_to_member_list(runasusers, ele_size, str_off);
if (cmndspec->runasuserlist == NULL)
goto oom;
}
/* Parse sudoRunAsGroup */
if (runasgroups != NULL) {
cmndspec->runasgrouplist =
array_to_member_list(runasgroups, ele_size, str_off);
if (cmndspec->runasgrouplist == NULL)
goto oom;
}
/* Parse sudoNotBefore / sudoNotAfter */
if (notbefore != NULL)
cmndspec->notbefore = parse_gentime(notbefore);
if (notafter != NULL)
cmndspec->notbefore = parse_gentime(notafter);
/* Parse sudoOptions. */
if (opts != NULL) {
for (; *((char **)opts) != NULL; opts = (char *)opts + ele_size) {
char *opt = *(char **)(*((char **)opts) + str_off);
char *var, *val;
int op;
op = sudo_ldap_parse_option(opt, &var, &val);
if (strcmp(var, "command_timeout") == 0) {
if (op == '=')
cmndspec->timeout = parse_timeout(val);
#ifdef HAVE_SELINUX
} else if (strcmp(var, "role") == 0) {
if (op == '=') {
if ((cmndspec->role = strdup(val)) == NULL)
goto oom;
}
} else if (strcmp(var, "type") == 0) {
if (op == '=') {
if ((cmndspec->type = strdup(val)) == NULL)
goto oom;
}
#endif /* HAVE_SELINUX */
#ifdef HAVE_PRIV_SET
} else if (strcmp(var, "privs") == 0) {
if (op == '=') {
if ((cmndspec->privs = strdup(val)) == NULL)
goto oom;
}
} else if (strcmp(val, "limitprivs") == 0) {
if (op == '=') {
if ((cmndspec->limitprivs = strdup(val)) == NULL)
goto oom;
}
#endif /* HAVE_PRIV_SET */
} else if (long_list) {
struct defaults *def = calloc(1, sizeof(*def));
if (def == NULL)
goto oom;
def->op = op;
if ((def->var = strdup(var)) == NULL) {
free(def);
goto oom;
}
if (val != NULL) {
if ((def->val = strdup(val)) == NULL) {
free(def->var);
free(def);
goto oom;
}
}
TAILQ_INSERT_TAIL(&priv->defaults, def, entries);
} else {
/* Convert to tags. */
if (op != true && op != false)
continue;
if (strcmp(var, "authenticate") == 0) {
cmndspec->tags.nopasswd = op == false;
} else if (strcmp(var, "sudoedit_follow") == 0) {
cmndspec->tags.follow = op == true;
} else if (strcmp(var, "noexec") == 0) {
cmndspec->tags.noexec = op == true;
} else if (strcmp(var, "setenv") == 0) {
cmndspec->tags.setenv = op == true;
} else if (strcmp(var, "mail_all_cmnds") == 0 ||
strcmp(var, "mail_always") == 0) {
cmndspec->tags.send_mail = op == true;
}
}
}
}
/* So we can inherit previous values. */
prev_cmndspec = cmndspec;
}
}
debug_return_ptr(priv);
oom:
sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
if (priv != NULL)
free_privilege(priv);
debug_return_ptr(NULL);
}
/*
* If a digest prefix is present, fills in struct sudo_digest
* and returns a pointer to it, updating cmnd to point to the
* command after the digest.
*/
struct sudo_digest *
sudo_ldap_extract_digest(char **cmnd, struct sudo_digest *digest)
{
char *ep, *cp = *cmnd;
int digest_type = SUDO_DIGEST_INVALID;
debug_decl(sudo_ldap_check_command, SUDOERS_DEBUG_LDAP)
/*
* Check for and extract a digest prefix, e.g.
* sha224:d06a2617c98d377c250edd470fd5e576327748d82915d6e33b5f8db1 /bin/ls
*/
if (cp[0] == 's' && cp[1] == 'h' && cp[2] == 'a') {
switch (cp[3]) {
case '2':
if (cp[4] == '2' && cp[5] == '4')
digest_type = SUDO_DIGEST_SHA224;
else if (cp[4] == '5' && cp[5] == '6')
digest_type = SUDO_DIGEST_SHA256;
break;
case '3':
if (cp[4] == '8' && cp[5] == '4')
digest_type = SUDO_DIGEST_SHA384;
break;
case '5':
if (cp[4] == '1' && cp[5] == '2')
digest_type = SUDO_DIGEST_SHA512;
break;
}
if (digest_type != SUDO_DIGEST_INVALID) {
cp += 6;
while (isblank((unsigned char)*cp))
cp++;
if (*cp == ':') {
cp++;
while (isblank((unsigned char)*cp))
cp++;
ep = cp;
while (*ep != '\0' && !isblank((unsigned char)*ep))
ep++;
if (*ep != '\0') {
digest->digest_type = digest_type;
digest->digest_str = strndup(cp, (size_t)(ep - cp));
if (digest->digest_str == NULL) {
sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
debug_return_ptr(NULL);
}
cp = ep + 1;
while (isblank((unsigned char)*cp))
cp++;
*cmnd = cp;
sudo_debug_printf(SUDO_DEBUG_INFO,
"%s digest %s for %s",
digest_type_to_name(digest_type),
digest->digest_str, cp);
debug_return_ptr(digest);
}
}
}
}
debug_return_ptr(NULL);
}