boringssl/crypto/conf/conf.c
David Benjamin 2d05568a7b Fix out-of-memory condition in conf.
conf has the ability to expand variables in config files. Repeatedly doing
this can lead to an exponential increase in the amount of memory required.
This places a limit on the length of a value that can result from an
expansion.

Credit to OSS-Fuzz for finding this problem.

(Imported from upstream's 6a6213556a80ab0a9eb926a1d6023b8bf44f2afd. This
also import's upstream's ee1ccd0a41ad068957fe65ba7521e593b51bbad4 which
we had previously missed.)

Change-Id: I9be06a7e8a062b5adcd00c974a7b245226123563
Reviewed-on: https://boringssl-review.googlesource.com/14316
Reviewed-by: Steven Valdez <svaldez@google.com>
Commit-Queue: Steven Valdez <svaldez@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2017-03-21 16:19:22 +00:00

804 lines
19 KiB
C

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.] */
#include <openssl/conf.h>
#include <string.h>
#include <ctype.h>
#include <openssl/bio.h>
#include <openssl/buf.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include "conf_def.h"
#include "internal.h"
#include "../internal.h"
/* The maximum length we can grow a value to after variable expansion. 64k
* should be more than enough for all reasonable uses. */
#define MAX_CONF_VALUE_LENGTH 65536
static uint32_t conf_value_hash(const CONF_VALUE *v) {
return (lh_strhash(v->section) << 2) ^ lh_strhash(v->name);
}
static int conf_value_cmp(const CONF_VALUE *a, const CONF_VALUE *b) {
int i;
if (a->section != b->section) {
i = strcmp(a->section, b->section);
if (i) {
return i;
}
}
if (a->name != NULL && b->name != NULL) {
return strcmp(a->name, b->name);
} else if (a->name == b->name) {
return 0;
} else {
return (a->name == NULL) ? -1 : 1;
}
}
CONF *NCONF_new(void *method) {
CONF *conf;
if (method != NULL) {
return NULL;
}
conf = OPENSSL_malloc(sizeof(CONF));
if (conf == NULL) {
return NULL;
}
conf->data = lh_CONF_VALUE_new(conf_value_hash, conf_value_cmp);
if (conf->data == NULL) {
OPENSSL_free(conf);
return NULL;
}
return conf;
}
CONF_VALUE *CONF_VALUE_new(void) {
CONF_VALUE *v = OPENSSL_malloc(sizeof(CONF_VALUE));
if (!v) {
OPENSSL_PUT_ERROR(CONF, ERR_R_MALLOC_FAILURE);
return NULL;
}
OPENSSL_memset(v, 0, sizeof(CONF_VALUE));
return v;
}
static void value_free_contents(CONF_VALUE *value) {
if (value->section) {
OPENSSL_free(value->section);
}
if (value->name) {
OPENSSL_free(value->name);
if (value->value) {
OPENSSL_free(value->value);
}
} else {
if (value->value) {
sk_CONF_VALUE_free((STACK_OF(CONF_VALUE)*)value->value);
}
}
}
static void value_free(CONF_VALUE *value) {
value_free_contents(value);
OPENSSL_free(value);
}
void NCONF_free(CONF *conf) {
if (conf == NULL || conf->data == NULL) {
return;
}
lh_CONF_VALUE_doall(conf->data, value_free);
lh_CONF_VALUE_free(conf->data);
OPENSSL_free(conf);
}
static CONF_VALUE *NCONF_new_section(const CONF *conf, const char *section) {
STACK_OF(CONF_VALUE) *sk = NULL;
int ok = 0;
CONF_VALUE *v = NULL, *old_value;
sk = sk_CONF_VALUE_new_null();
v = CONF_VALUE_new();
if (sk == NULL || v == NULL) {
goto err;
}
v->section = OPENSSL_strdup(section);
if (v->section == NULL) {
goto err;
}
v->name = NULL;
v->value = (char *)sk;
if (!lh_CONF_VALUE_insert(conf->data, &old_value, v)) {
goto err;
}
if (old_value) {
value_free(old_value);
}
ok = 1;
err:
if (!ok) {
if (sk != NULL) {
sk_CONF_VALUE_free(sk);
}
if (v != NULL) {
OPENSSL_free(v);
}
v = NULL;
}
return v;
}
static int str_copy(CONF *conf, char *section, char **pto, char *from) {
int q, r, rr = 0, to = 0, len = 0;
char *s, *e, *rp, *rrp, *np, *cp, v;
const char *p;
BUF_MEM *buf;
buf = BUF_MEM_new();
if (buf == NULL) {
return 0;
}
len = strlen(from) + 1;
if (!BUF_MEM_grow(buf, len)) {
goto err;
}
for (;;) {
if (IS_QUOTE(conf, *from)) {
q = *from;
from++;
while (!IS_EOF(conf, *from) && (*from != q)) {
if (IS_ESC(conf, *from)) {
from++;
if (IS_EOF(conf, *from)) {
break;
}
}
buf->data[to++] = *(from++);
}
if (*from == q) {
from++;
}
} else if (IS_DQUOTE(conf, *from)) {
q = *from;
from++;
while (!IS_EOF(conf, *from)) {
if (*from == q) {
if (*(from + 1) == q) {
from++;
} else {
break;
}
}
buf->data[to++] = *(from++);
}
if (*from == q) {
from++;
}
} else if (IS_ESC(conf, *from)) {
from++;
v = *(from++);
if (IS_EOF(conf, v)) {
break;
} else if (v == 'r') {
v = '\r';
} else if (v == 'n') {
v = '\n';
} else if (v == 'b') {
v = '\b';
} else if (v == 't') {
v = '\t';
}
buf->data[to++] = v;
} else if (IS_EOF(conf, *from)) {
break;
} else if (*from == '$') {
/* try to expand it */
rrp = NULL;
s = &(from[1]);
if (*s == '{') {
q = '}';
} else if (*s == '(') {
q = ')';
} else {
q = 0;
}
if (q) {
s++;
}
cp = section;
e = np = s;
while (IS_ALPHA_NUMERIC(conf, *e)) {
e++;
}
if (e[0] == ':' && e[1] == ':') {
cp = np;
rrp = e;
rr = *e;
*rrp = '\0';
e += 2;
np = e;
while (IS_ALPHA_NUMERIC(conf, *e)) {
e++;
}
}
r = *e;
*e = '\0';
rp = e;
if (q) {
if (r != q) {
OPENSSL_PUT_ERROR(CONF, CONF_R_NO_CLOSE_BRACE);
goto err;
}
e++;
}
/* So at this point we have
* np which is the start of the name string which is
* '\0' terminated.
* cp which is the start of the section string which is
* '\0' terminated.
* e is the 'next point after'.
* r and rr are the chars replaced by the '\0'
* rp and rrp is where 'r' and 'rr' came from. */
p = NCONF_get_string(conf, cp, np);
if (rrp != NULL) {
*rrp = rr;
}
*rp = r;
if (p == NULL) {
OPENSSL_PUT_ERROR(CONF, CONF_R_VARIABLE_HAS_NO_VALUE);
goto err;
}
size_t newsize = strlen(p) + buf->length - (e - from);
if (newsize > MAX_CONF_VALUE_LENGTH) {
OPENSSL_PUT_ERROR(CONF, CONF_R_VARIABLE_EXPANSION_TOO_LONG);
goto err;
}
if (!BUF_MEM_grow_clean(buf, newsize)) {
OPENSSL_PUT_ERROR(CONF, ERR_R_MALLOC_FAILURE);
goto err;
}
while (*p) {
buf->data[to++] = *(p++);
}
/* Since we change the pointer 'from', we also have
to change the perceived length of the string it
points at. /RL */
len -= e - from;
from = e;
/* In case there were no braces or parenthesis around
the variable reference, we have to put back the
character that was replaced with a '\0'. /RL */
*rp = r;
} else {
buf->data[to++] = *(from++);
}
}
buf->data[to] = '\0';
if (*pto != NULL) {
OPENSSL_free(*pto);
}
*pto = buf->data;
OPENSSL_free(buf);
return 1;
err:
if (buf != NULL) {
BUF_MEM_free(buf);
}
return 0;
}
static CONF_VALUE *get_section(const CONF *conf, const char *section) {
CONF_VALUE template;
OPENSSL_memset(&template, 0, sizeof(template));
template.section = (char *) section;
return lh_CONF_VALUE_retrieve(conf->data, &template);
}
STACK_OF(CONF_VALUE) *NCONF_get_section(const CONF *conf, const char *section) {
CONF_VALUE *section_value = get_section(conf, section);
if (section_value == NULL) {
return NULL;
}
return (STACK_OF(CONF_VALUE)*) section_value->value;
}
const char *NCONF_get_string(const CONF *conf, const char *section,
const char *name) {
CONF_VALUE template, *value;
OPENSSL_memset(&template, 0, sizeof(template));
template.section = (char *) section;
template.name = (char *) name;
value = lh_CONF_VALUE_retrieve(conf->data, &template);
if (value == NULL) {
return NULL;
}
return value->value;
}
static int add_string(const CONF *conf, CONF_VALUE *section,
CONF_VALUE *value) {
STACK_OF(CONF_VALUE) *section_stack = (STACK_OF(CONF_VALUE)*) section->value;
CONF_VALUE *old_value;
value->section = OPENSSL_strdup(section->section);
if (!sk_CONF_VALUE_push(section_stack, value)) {
return 0;
}
if (!lh_CONF_VALUE_insert(conf->data, &old_value, value)) {
return 0;
}
if (old_value != NULL) {
(void)sk_CONF_VALUE_delete_ptr(section_stack, old_value);
value_free(old_value);
}
return 1;
}
static char *eat_ws(CONF *conf, char *p) {
while (IS_WS(conf, *p) && !IS_EOF(conf, *p)) {
p++;
}
return p;
}
#define scan_esc(conf, p) (((IS_EOF((conf), (p)[1])) ? ((p) + 1) : ((p) + 2)))
static char *eat_alpha_numeric(CONF *conf, char *p) {
for (;;) {
if (IS_ESC(conf, *p)) {
p = scan_esc(conf, p);
continue;
}
if (!IS_ALPHA_NUMERIC_PUNCT(conf, *p)) {
return p;
}
p++;
}
}
static char *scan_quote(CONF *conf, char *p) {
int q = *p;
p++;
while (!IS_EOF(conf, *p) && *p != q) {
if (IS_ESC(conf, *p)) {
p++;
if (IS_EOF(conf, *p)) {
return p;
}
}
p++;
}
if (*p == q) {
p++;
}
return p;
}
static char *scan_dquote(CONF *conf, char *p) {
int q = *p;
p++;
while (!(IS_EOF(conf, *p))) {
if (*p == q) {
if (*(p + 1) == q) {
p++;
} else {
break;
}
}
p++;
}
if (*p == q) {
p++;
}
return p;
}
static void clear_comments(CONF *conf, char *p) {
for (;;) {
if (IS_FCOMMENT(conf, *p)) {
*p = '\0';
return;
}
if (!IS_WS(conf, *p)) {
break;
}
p++;
}
for (;;) {
if (IS_COMMENT(conf, *p)) {
*p = '\0';
return;
}
if (IS_DQUOTE(conf, *p)) {
p = scan_dquote(conf, p);
continue;
}
if (IS_QUOTE(conf, *p)) {
p = scan_quote(conf, p);
continue;
}
if (IS_ESC(conf, *p)) {
p = scan_esc(conf, p);
continue;
}
if (IS_EOF(conf, *p)) {
return;
} else {
p++;
}
}
}
static int def_load_bio(CONF *conf, BIO *in, long *out_error_line) {
static const size_t CONFBUFSIZE = 512;
int bufnum = 0, i, ii;
BUF_MEM *buff = NULL;
char *s, *p, *end;
int again;
long eline = 0;
char btmp[DECIMAL_SIZE(eline) + 1];
CONF_VALUE *v = NULL, *tv;
CONF_VALUE *sv = NULL;
char *section = NULL, *buf;
char *start, *psection, *pname;
if ((buff = BUF_MEM_new()) == NULL) {
OPENSSL_PUT_ERROR(CONF, ERR_R_BUF_LIB);
goto err;
}
section = OPENSSL_strdup("default");
if (section == NULL) {
OPENSSL_PUT_ERROR(CONF, ERR_R_MALLOC_FAILURE);
goto err;
}
sv = NCONF_new_section(conf, section);
if (sv == NULL) {
OPENSSL_PUT_ERROR(CONF, CONF_R_UNABLE_TO_CREATE_NEW_SECTION);
goto err;
}
bufnum = 0;
again = 0;
for (;;) {
if (!BUF_MEM_grow(buff, bufnum + CONFBUFSIZE)) {
OPENSSL_PUT_ERROR(CONF, ERR_R_BUF_LIB);
goto err;
}
p = &(buff->data[bufnum]);
*p = '\0';
BIO_gets(in, p, CONFBUFSIZE - 1);
p[CONFBUFSIZE - 1] = '\0';
ii = i = strlen(p);
if (i == 0 && !again) {
break;
}
again = 0;
while (i > 0) {
if ((p[i - 1] != '\r') && (p[i - 1] != '\n')) {
break;
} else {
i--;
}
}
/* we removed some trailing stuff so there is a new
* line on the end. */
if (ii && i == ii) {
again = 1; /* long line */
} else {
p[i] = '\0';
eline++; /* another input line */
}
/* we now have a line with trailing \r\n removed */
/* i is the number of bytes */
bufnum += i;
v = NULL;
/* check for line continuation */
if (bufnum >= 1) {
/* If we have bytes and the last char '\\' and
* second last char is not '\\' */
p = &(buff->data[bufnum - 1]);
if (IS_ESC(conf, p[0]) && ((bufnum <= 1) || !IS_ESC(conf, p[-1]))) {
bufnum--;
again = 1;
}
}
if (again) {
continue;
}
bufnum = 0;
buf = buff->data;
clear_comments(conf, buf);
s = eat_ws(conf, buf);
if (IS_EOF(conf, *s)) {
continue; /* blank line */
}
if (*s == '[') {
char *ss;
s++;
start = eat_ws(conf, s);
ss = start;
again:
end = eat_alpha_numeric(conf, ss);
p = eat_ws(conf, end);
if (*p != ']') {
if (*p != '\0' && ss != p) {
ss = p;
goto again;
}
OPENSSL_PUT_ERROR(CONF, CONF_R_MISSING_CLOSE_SQUARE_BRACKET);
goto err;
}
*end = '\0';
if (!str_copy(conf, NULL, &section, start)) {
goto err;
}
if ((sv = get_section(conf, section)) == NULL) {
sv = NCONF_new_section(conf, section);
}
if (sv == NULL) {
OPENSSL_PUT_ERROR(CONF, CONF_R_UNABLE_TO_CREATE_NEW_SECTION);
goto err;
}
continue;
} else {
pname = s;
psection = NULL;
end = eat_alpha_numeric(conf, s);
if ((end[0] == ':') && (end[1] == ':')) {
*end = '\0';
end += 2;
psection = pname;
pname = end;
end = eat_alpha_numeric(conf, end);
}
p = eat_ws(conf, end);
if (*p != '=') {
OPENSSL_PUT_ERROR(CONF, CONF_R_MISSING_EQUAL_SIGN);
goto err;
}
*end = '\0';
p++;
start = eat_ws(conf, p);
while (!IS_EOF(conf, *p)) {
p++;
}
p--;
while ((p != start) && (IS_WS(conf, *p))) {
p--;
}
p++;
*p = '\0';
if (!(v = CONF_VALUE_new())) {
goto err;
}
if (psection == NULL) {
psection = section;
}
v->name = OPENSSL_strdup(pname);
if (v->name == NULL) {
OPENSSL_PUT_ERROR(CONF, ERR_R_MALLOC_FAILURE);
goto err;
}
if (!str_copy(conf, psection, &(v->value), start)) {
goto err;
}
if (strcmp(psection, section) != 0) {
if ((tv = get_section(conf, psection)) == NULL) {
tv = NCONF_new_section(conf, psection);
}
if (tv == NULL) {
OPENSSL_PUT_ERROR(CONF, CONF_R_UNABLE_TO_CREATE_NEW_SECTION);
goto err;
}
} else {
tv = sv;
}
if (add_string(conf, tv, v) == 0) {
OPENSSL_PUT_ERROR(CONF, ERR_R_MALLOC_FAILURE);
goto err;
}
v = NULL;
}
}
if (buff != NULL) {
BUF_MEM_free(buff);
}
if (section != NULL) {
OPENSSL_free(section);
}
return 1;
err:
if (buff != NULL) {
BUF_MEM_free(buff);
}
if (section != NULL) {
OPENSSL_free(section);
}
if (out_error_line != NULL) {
*out_error_line = eline;
}
BIO_snprintf(btmp, sizeof btmp, "%ld", eline);
ERR_add_error_data(2, "line ", btmp);
if (v != NULL) {
if (v->name != NULL) {
OPENSSL_free(v->name);
}
if (v->value != NULL) {
OPENSSL_free(v->value);
}
if (v != NULL) {
OPENSSL_free(v);
}
}
return 0;
}
int NCONF_load(CONF *conf, const char *filename, long *out_error_line) {
BIO *in = BIO_new_file(filename, "rb");
int ret;
if (in == NULL) {
OPENSSL_PUT_ERROR(CONF, ERR_R_SYS_LIB);
return 0;
}
ret = def_load_bio(conf, in, out_error_line);
BIO_free(in);
return ret;
}
int NCONF_load_bio(CONF *conf, BIO *bio, long *out_error_line) {
return def_load_bio(conf, bio, out_error_line);
}
int CONF_parse_list(const char *list, char sep, int remove_whitespace,
int (*list_cb)(const char *elem, int len, void *usr),
void *arg) {
int ret;
const char *lstart, *tmpend, *p;
if (list == NULL) {
OPENSSL_PUT_ERROR(CONF, CONF_R_LIST_CANNOT_BE_NULL);
return 0;
}
lstart = list;
for (;;) {
if (remove_whitespace) {
while (*lstart && isspace((unsigned char)*lstart)) {
lstart++;
}
}
p = strchr(lstart, sep);
if (p == lstart || !*lstart) {
ret = list_cb(NULL, 0, arg);
} else {
if (p) {
tmpend = p - 1;
} else {
tmpend = lstart + strlen(lstart) - 1;
}
if (remove_whitespace) {
while (isspace((unsigned char)*tmpend)) {
tmpend--;
}
}
ret = list_cb(lstart, tmpend - lstart + 1, arg);
}
if (ret <= 0) {
return ret;
}
if (p == NULL) {
return 1;
}
lstart = p + 1;
}
}
int CONF_modules_load_file(CONF_MUST_BE_NULL *filename, const char *appname,
unsigned long flags) {
return 1;
}
void CONF_modules_free(void) {}
void OPENSSL_config(CONF_MUST_BE_NULL *config_name) {}
void OPENSSL_no_config(void) {}