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Files
sudo/plugins/sudoers/cvtsudoers_ldif.c
Todd C. Miller 6286ce1d16 Store column number for aliases, defaults and userspecs too.
This is used to provided the column number along with the line
number in error messages.  For aliases we store the column of the
alias name, not the value since that is what visudo generally needs.
2020-11-02 05:39:06 -07:00

713 lines
19 KiB
C

/*
* SPDX-License-Identifier: ISC
*
* Copyright (c) 2018 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 <unistd.h>
#include <stdarg.h>
#include "sudoers.h"
#include "sudo_ldap.h"
#include "redblack.h"
#include "cvtsudoers.h"
#include "sudo_lbuf.h"
#include <gram.h>
struct seen_user {
const char *name;
unsigned long count;
};
static struct rbtree *seen_users;
static int
seen_user_compare(const void *aa, const void *bb)
{
const struct seen_user *a = aa;
const struct seen_user *b = bb;
return strcasecmp(a->name, b->name);
}
static void
seen_user_free(void *v)
{
struct seen_user *su = v;
free((void *)su->name);
free(su);
}
static bool
safe_string(const char *str)
{
unsigned int ch = *str++;
debug_decl(safe_string, SUDOERS_DEBUG_UTIL);
/* Initial char must be <= 127 and not LF, CR, SPACE, ':', '<' */
switch (ch) {
case '\0':
debug_return_bool(true);
case '\n':
case '\r':
case ' ':
case ':':
case '<':
debug_return_bool(false);
default:
if (ch > 127)
debug_return_bool(false);
}
/* Any value <= 127 decimal except NUL, LF, and CR is safe */
while ((ch = *str++) != '\0') {
if (ch > 127 || ch == '\n' || ch == '\r')
debug_return_bool(false);
}
debug_return_bool(true);
}
static bool
print_attribute_ldif(FILE *fp, const char *name, const char *value)
{
const unsigned char *uvalue = (unsigned char *)value;
char *encoded = NULL;
size_t esize;
debug_decl(print_attribute_ldif, SUDOERS_DEBUG_UTIL);
if (!safe_string(value)) {
const size_t vlen = strlen(value);
esize = ((vlen + 2) / 3 * 4) + 1;
if ((encoded = malloc(esize)) == NULL)
debug_return_bool(false);
if (base64_encode(uvalue, vlen, encoded, esize) == (size_t)-1) {
free(encoded);
debug_return_bool(false);
}
fprintf(fp, "%s:: %s\n", name, encoded);
free(encoded);
} else if (*value != '\0') {
fprintf(fp, "%s: %s\n", name, value);
} else {
fprintf(fp, "%s:\n", name);
}
debug_return_bool(true);
}
/*
* Print sudoOptions from a defaults_list.
*/
static bool
print_options_ldif(FILE *fp, struct defaults_list *options)
{
struct defaults *opt;
char *attr_val;
int len;
debug_decl(print_options_ldif, SUDOERS_DEBUG_UTIL);
TAILQ_FOREACH(opt, options, entries) {
if (opt->type != DEFAULTS)
continue; /* don't support bound defaults */
if (opt->val != NULL) {
/* There is no need to double quote values here. */
len = asprintf(&attr_val, "%s%s%s", opt->var,
opt->op == '+' ? "+=" : opt->op == '-' ? "-=" : "=", opt->val);
} else {
/* Boolean flag. */
len = asprintf(&attr_val, "%s%s",
opt->op == false ? "!" : "", opt->var);
}
if (len == -1) {
sudo_fatalx(U_("%s: %s"), __func__,
U_("unable to allocate memory"));
}
print_attribute_ldif(fp, "sudoOption", attr_val);
free(attr_val);
}
debug_return_bool(!ferror(fp));
}
/*
* Print global Defaults in a single sudoRole object.
*/
static bool
print_global_defaults_ldif(FILE *fp, struct sudoers_parse_tree *parse_tree,
const char *base)
{
unsigned int count = 0;
struct sudo_lbuf lbuf;
struct defaults *opt;
char *dn;
debug_decl(print_global_defaults_ldif, SUDOERS_DEBUG_UTIL);
sudo_lbuf_init(&lbuf, NULL, 0, NULL, 80);
TAILQ_FOREACH(opt, &parse_tree->defaults, entries) {
/* Skip bound Defaults (unsupported). */
if (opt->type == DEFAULTS) {
count++;
} else {
lbuf.len = 0;
sudo_lbuf_append(&lbuf, "# ");
sudoers_format_default_line(&lbuf, parse_tree, opt, false, true);
fprintf(fp, "# Unable to translate %s:%d:%d:\n%s\n",
opt->file, opt->line, opt->column, lbuf.buf);
}
}
sudo_lbuf_destroy(&lbuf);
if (count == 0)
debug_return_bool(true);
if (asprintf(&dn, "cn=defaults,%s", base) == -1) {
sudo_fatalx(U_("%s: %s"), __func__,
U_("unable to allocate memory"));
}
print_attribute_ldif(fp, "dn", dn);
free(dn);
print_attribute_ldif(fp, "objectClass", "top");
print_attribute_ldif(fp, "objectClass", "sudoRole");
print_attribute_ldif(fp, "cn", "defaults");
print_attribute_ldif(fp, "description", "Default sudoOption's go here");
print_options_ldif(fp, &parse_tree->defaults);
putc('\n', fp);
debug_return_bool(!ferror(fp));
}
/*
* Format a sudo_command as a string.
* Returns the formatted, dynamically allocated string or dies on error.
*/
static char *
format_cmnd(struct sudo_command *c, bool negated)
{
struct command_digest *digest;
char *buf, *cp, *cmnd;
size_t bufsiz;
int len;
debug_decl(format_cmnd, SUDOERS_DEBUG_UTIL);
cmnd = c->cmnd ? c->cmnd : "ALL";
bufsiz = negated + strlen(cmnd) + 1;
if (c->args != NULL)
bufsiz += 1 + strlen(c->args);
TAILQ_FOREACH(digest, &c->digests, entries) {
bufsiz += strlen(digest_type_to_name(digest->digest_type)) + 1 +
strlen(digest->digest_str) + 1;
if (TAILQ_NEXT(digest, entries) != NULL)
bufsiz += 2;
}
if ((buf = malloc(bufsiz)) == NULL) {
sudo_fatalx(U_("%s: %s"), __func__,
U_("unable to allocate memory"));
}
cp = buf;
TAILQ_FOREACH(digest, &c->digests, entries) {
len = snprintf(cp, bufsiz - (cp - buf), "%s:%s%s ",
digest_type_to_name(digest->digest_type), digest->digest_str,
TAILQ_NEXT(digest, entries) ? "," : "");
if (len < 0 || len >= (int)bufsiz - (cp - buf))
sudo_fatalx(U_("internal error, %s overflow"), __func__);
cp += len;
}
len = snprintf(cp, bufsiz - (cp - buf), "%s%s%s%s", negated ? "!" : "",
cmnd, c->args ? " " : "", c->args ? c->args : "");
if (len < 0 || len >= (int)bufsiz - (cp - buf))
sudo_fatalx(U_("internal error, %s overflow"), __func__);
debug_return_str(buf);
}
/*
* Print struct member in LDIF format as the specified attribute.
* See print_member_int() in parse.c.
*/
static void
print_member_ldif(FILE *fp, struct sudoers_parse_tree *parse_tree, char *name,
int type, bool negated, int alias_type, const char *attr_name)
{
struct alias *a;
struct member *m;
char *attr_val;
int len;
debug_decl(print_member_ldif, SUDOERS_DEBUG_UTIL);
switch (type) {
case MYSELF:
/* Only valid for sudoRunasUser */
print_attribute_ldif(fp, attr_name, "");
break;
case ALL:
if (name == NULL) {
print_attribute_ldif(fp, attr_name, negated ? "!ALL" : "ALL");
break;
}
FALLTHROUGH;
case COMMAND:
attr_val = format_cmnd((struct sudo_command *)name, negated);
print_attribute_ldif(fp, attr_name, attr_val);
free(attr_val);
break;
case ALIAS:
if ((a = alias_get(parse_tree, name, alias_type)) != NULL) {
TAILQ_FOREACH(m, &a->members, entries) {
print_member_ldif(fp, parse_tree, m->name, m->type,
negated ? !m->negated : m->negated, alias_type, attr_name);
}
alias_put(a);
break;
}
FALLTHROUGH;
default:
len = asprintf(&attr_val, "%s%s", negated ? "!" : "", name);
if (len == -1) {
sudo_fatalx(U_("%s: %s"), __func__,
U_("unable to allocate memory"));
}
print_attribute_ldif(fp, attr_name, attr_val);
free(attr_val);
break;
}
debug_return;
}
/*
* Print a Cmnd_Spec in LDIF format.
* A pointer to the next Cmnd_Spec is passed in to make it possible to
* merge adjacent entries that are identical in all but the command.
*/
static void
print_cmndspec_ldif(FILE *fp, struct sudoers_parse_tree *parse_tree,
struct cmndspec *cs, struct cmndspec **nextp, struct defaults_list *options)
{
struct cmndspec *next = *nextp;
struct member *m;
struct tm *tp;
char *attr_val;
bool last_one;
char timebuf[sizeof("20120727121554Z")];
debug_decl(print_cmndspec_ldif, SUDOERS_DEBUG_UTIL);
/* Print runasuserlist as sudoRunAsUser attributes */
if (cs->runasuserlist != NULL) {
TAILQ_FOREACH(m, cs->runasuserlist, entries) {
print_member_ldif(fp, parse_tree, m->name, m->type, m->negated,
RUNASALIAS, "sudoRunAsUser");
}
}
/* Print runasgrouplist as sudoRunAsGroup attributes */
if (cs->runasgrouplist != NULL) {
TAILQ_FOREACH(m, cs->runasgrouplist, entries) {
print_member_ldif(fp, parse_tree, m->name, m->type, m->negated,
RUNASALIAS, "sudoRunAsGroup");
}
}
/* Print sudoNotBefore and sudoNotAfter attributes */
if (cs->notbefore != UNSPEC) {
if ((tp = gmtime(&cs->notbefore)) == NULL) {
sudo_warn("%s", U_("unable to get GMT time"));
} else {
if (strftime(timebuf, sizeof(timebuf), "%Y%m%d%H%M%SZ", tp) == 0) {
sudo_warnx("%s", U_("unable to format timestamp"));
} else {
print_attribute_ldif(fp, "sudoNotBefore", timebuf);
}
}
}
if (cs->notafter != UNSPEC) {
if ((tp = gmtime(&cs->notafter)) == NULL) {
sudo_warn("%s", U_("unable to get GMT time"));
} else {
if (strftime(timebuf, sizeof(timebuf), "%Y%m%d%H%M%SZ", tp) == 0) {
sudo_warnx("%s", U_("unable to format timestamp"));
} else {
print_attribute_ldif(fp, "sudoNotAfter", timebuf);
}
}
}
/* Print timeout as a sudoOption. */
if (cs->timeout > 0) {
if (asprintf(&attr_val, "command_timeout=%d", cs->timeout) == -1) {
sudo_fatalx(U_("%s: %s"), __func__,
U_("unable to allocate memory"));
}
print_attribute_ldif(fp, "sudoOption", attr_val);
free(attr_val);
}
/* Print tags as sudoOption attributes */
if (TAGS_SET(cs->tags)) {
struct cmndtag tag = cs->tags;
if (tag.nopasswd != UNSPEC) {
print_attribute_ldif(fp, "sudoOption",
tag.nopasswd ? "!authenticate" : "authenticate");
}
if (tag.noexec != UNSPEC) {
print_attribute_ldif(fp, "sudoOption",
tag.noexec ? "noexec" : "!noexec");
}
if (tag.send_mail != UNSPEC) {
if (tag.send_mail) {
print_attribute_ldif(fp, "sudoOption", "mail_all_cmnds");
} else {
print_attribute_ldif(fp, "sudoOption", "!mail_all_cmnds");
print_attribute_ldif(fp, "sudoOption", "!mail_always");
print_attribute_ldif(fp, "sudoOption", "!mail_no_perms");
}
}
if (tag.setenv != UNSPEC && tag.setenv != IMPLIED) {
print_attribute_ldif(fp, "sudoOption",
tag.setenv ? "setenv" : "!setenv");
}
if (tag.follow != UNSPEC) {
print_attribute_ldif(fp, "sudoOption",
tag.follow ? "sudoedit_follow" : "!sudoedit_follow");
}
if (tag.log_input != UNSPEC) {
print_attribute_ldif(fp, "sudoOption",
tag.log_input ? "log_input" : "!log_input");
}
if (tag.log_output != UNSPEC) {
print_attribute_ldif(fp, "sudoOption",
tag.log_output ? "log_output" : "!log_output");
}
}
print_options_ldif(fp, options);
/* Print runchroot and runcwd. */
if (cs->runchroot != NULL) {
if (asprintf(&attr_val, "runchroot=%s", cs->runchroot) == -1) {
sudo_fatalx(U_("%s: %s"), __func__,
U_("unable to allocate memory"));
}
print_attribute_ldif(fp, "sudoOption", attr_val);
free(attr_val);
}
if (cs->runcwd != NULL) {
if (asprintf(&attr_val, "runcwd=%s", cs->runcwd) == -1) {
sudo_fatalx(U_("%s: %s"), __func__,
U_("unable to allocate memory"));
}
print_attribute_ldif(fp, "sudoOption", attr_val);
free(attr_val);
}
#ifdef HAVE_SELINUX
/* Print SELinux role/type */
if (cs->role != NULL && cs->type != NULL) {
if (asprintf(&attr_val, "role=%s", cs->role) == -1) {
sudo_fatalx(U_("%s: %s"), __func__,
U_("unable to allocate memory"));
}
print_attribute_ldif(fp, "sudoOption", attr_val);
free(attr_val);
if (asprintf(&attr_val, "type=%s", cs->type) == -1) {
sudo_fatalx(U_("%s: %s"), __func__,
U_("unable to allocate memory"));
}
print_attribute_ldif(fp, "sudoOption", attr_val);
free(attr_val);
}
#endif /* HAVE_SELINUX */
#ifdef HAVE_PRIV_SET
/* Print Solaris privs/limitprivs */
if (cs->privs != NULL || cs->limitprivs != NULL) {
if (cs->privs != NULL) {
if (asprintf(&attr_val, "privs=%s", cs->privs) == -1) {
sudo_fatalx(U_("%s: %s"), __func__,
U_("unable to allocate memory"));
}
print_attribute_ldif(fp, "sudoOption", attr_val);
free(attr_val);
}
if (cs->limitprivs != NULL) {
if (asprintf(&attr_val, "limitprivs=%s", cs->limitprivs) == -1) {
sudo_fatalx(U_("%s: %s"), __func__,
U_("unable to allocate memory"));
}
print_attribute_ldif(fp, "sudoOption", attr_val);
free(attr_val);
}
}
#endif /* HAVE_PRIV_SET */
/*
* Merge adjacent commands with matching tags, runas, SELinux
* role/type and Solaris priv settings.
*/
for (;;) {
/* Does the next entry differ only in the command itself? */
/* XXX - move into a function that returns bool */
/* XXX - TAG_SET does not account for implied SETENV */
last_one = next == NULL ||
RUNAS_CHANGED(cs, next) || TAGS_CHANGED(cs->tags, next->tags)
#ifdef HAVE_PRIV_SET
|| cs->privs != next->privs || cs->limitprivs != next->limitprivs
#endif /* HAVE_PRIV_SET */
#ifdef HAVE_SELINUX
|| cs->role != next->role || cs->type != next->type
#endif /* HAVE_SELINUX */
|| cs->runchroot != next->runchroot || cs->runcwd != next->runcwd;
print_member_ldif(fp, parse_tree, cs->cmnd->name, cs->cmnd->type,
cs->cmnd->negated, CMNDALIAS, "sudoCommand");
if (last_one)
break;
cs = next;
next = TAILQ_NEXT(cs, entries);
}
*nextp = next;
debug_return;
}
/*
* Convert user name to cn, avoiding duplicates and quoting as needed.
* See http://www.faqs.org/rfcs/rfc2253.html
*/
static char *
user_to_cn(const char *user)
{
struct seen_user key, *su = NULL;
struct rbnode *node;
const char *src;
char *cn, *dst;
size_t size;
debug_decl(user_to_cn, SUDOERS_DEBUG_UTIL);
/* Allocate as much as we could possibly need. */
size = (2 * strlen(user)) + 64 + 1;
if ((cn = malloc(size)) == NULL)
goto bad;
/*
* Increment the number of times we have seen this user.
*/
key.name = user;
node = rbfind(seen_users, &key);
if (node != NULL) {
su = node->data;
} else {
if ((su = malloc(sizeof(*su))) == NULL)
goto bad;
su->count = 0;
if ((su->name = strdup(user)) == NULL)
goto bad;
if (rbinsert(seen_users, su, NULL) != 0)
goto bad;
}
/* Build cn, quoting special chars as needed (we allocated 2 x len). */
for (src = user, dst = cn; *src != '\0'; src++) {
switch (*src) {
case ',':
case '+':
case '"':
case '\\':
case '<':
case '>':
case '#':
case ';':
*dst++ = '\\'; /* always escape */
break;
case ' ':
if (src == user || src[1] == '\0')
*dst++ = '\\'; /* only escape at beginning or end of string */
break;
default:
break;
}
*dst++ = *src;
}
*dst = '\0';
/* Append count if there are duplicate users (cn must be unique). */
if (su->count != 0) {
size -= (size_t)(dst - cn);
if ((size_t)snprintf(dst, size, "_%lu", su->count) >= size) {
sudo_warnx(U_("internal error, %s overflow"), __func__);
goto bad;
}
}
su->count++;
debug_return_str(cn);
bad:
if (su != NULL && su->count == 0)
seen_user_free(su);
free(cn);
debug_return_str(NULL);
}
/*
* Print a single User_Spec.
*/
static bool
print_userspec_ldif(FILE *fp, struct sudoers_parse_tree *parse_tree,
struct userspec *us, struct cvtsudoers_config *conf)
{
struct privilege *priv;
struct member *m;
struct cmndspec *cs, *next;
debug_decl(print_userspec_ldif, SUDOERS_DEBUG_UTIL);
/*
* Each userspec struct may contain multiple privileges for
* the user. We export each privilege as a separate sudoRole
* object for simplicity's sake.
*/
TAILQ_FOREACH(priv, &us->privileges, entries) {
TAILQ_FOREACH_SAFE(cs, &priv->cmndlist, entries, next) {
const char *base = conf->sudoers_base;
char *cn, *dn;
/*
* Increment the number of times we have seen this user.
* If more than one user is listed, just use the first one.
*/
m = TAILQ_FIRST(&us->users);
cn = user_to_cn(m->type == ALL ? "ALL" : m->name);
if (cn == NULL || asprintf(&dn, "cn=%s,%s", cn, base) == -1) {
sudo_fatalx(U_("%s: %s"), __func__,
U_("unable to allocate memory"));
}
print_attribute_ldif(fp, "dn", dn);
print_attribute_ldif(fp, "objectClass", "top");
print_attribute_ldif(fp, "objectClass", "sudoRole");
print_attribute_ldif(fp, "cn", cn);
free(cn);
free(dn);
TAILQ_FOREACH(m, &us->users, entries) {
print_member_ldif(fp, parse_tree, m->name, m->type, m->negated,
USERALIAS, "sudoUser");
}
TAILQ_FOREACH(m, &priv->hostlist, entries) {
print_member_ldif(fp, parse_tree, m->name, m->type, m->negated,
HOSTALIAS, "sudoHost");
}
print_cmndspec_ldif(fp, parse_tree, cs, &next, &priv->defaults);
if (conf->sudo_order != 0) {
char numbuf[(((sizeof(conf->sudo_order) * 8) + 2) / 3) + 2];
if (conf->order_max != 0 && conf->sudo_order > conf->order_max) {
sudo_fatalx(U_("too many sudoers entries, maximum %u"),
conf->order_padding);
}
(void)snprintf(numbuf, sizeof(numbuf), "%u", conf->sudo_order);
print_attribute_ldif(fp, "sudoOrder", numbuf);
putc('\n', fp);
conf->sudo_order += conf->order_increment;
}
}
}
debug_return_bool(!ferror(fp));
}
/*
* Print User_Specs.
*/
static bool
print_userspecs_ldif(FILE *fp, struct sudoers_parse_tree *parse_tree,
struct cvtsudoers_config *conf)
{
struct userspec *us;
debug_decl(print_userspecs_ldif, SUDOERS_DEBUG_UTIL);
TAILQ_FOREACH(us, &parse_tree->userspecs, entries) {
if (!print_userspec_ldif(fp, parse_tree, us, conf))
debug_return_bool(false);
}
debug_return_bool(true);
}
/*
* Export the parsed sudoers file in LDIF format.
*/
bool
convert_sudoers_ldif(struct sudoers_parse_tree *parse_tree,
const char *output_file, struct cvtsudoers_config *conf)
{
bool ret = true;
FILE *output_fp = stdout;
debug_decl(convert_sudoers_ldif, SUDOERS_DEBUG_UTIL);
if (conf->sudoers_base == NULL) {
sudo_fatalx("%s", U_("the SUDOERS_BASE environment variable is not set and the -b option was not specified."));
}
if (output_file != NULL && strcmp(output_file, "-") != 0) {
if ((output_fp = fopen(output_file, "w")) == NULL)
sudo_fatal(U_("unable to open %s"), output_file);
}
/* Create a dictionary of already-seen users. */
seen_users = rbcreate(seen_user_compare);
/* Dump global Defaults in LDIF format. */
if (!ISSET(conf->suppress, SUPPRESS_DEFAULTS))
print_global_defaults_ldif(output_fp, parse_tree, conf->sudoers_base);
/* Dump User_Specs in LDIF format, expanding Aliases. */
if (!ISSET(conf->suppress, SUPPRESS_PRIVS))
print_userspecs_ldif(output_fp, parse_tree, conf);
/* Clean up. */
rbdestroy(seen_users, seen_user_free);
(void)fflush(output_fp);
if (ferror(output_fp))
ret = false;
if (output_fp != stdout)
fclose(output_fp);
debug_return_bool(ret);
}