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openssl/crypto/conf/conf_def.c
Matt Caswell 8a585601fe 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.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2894)
2017-03-12 00:19:14 +00:00

642 lines
16 KiB
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/*
* Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
/* Part of the code in here was originally in conf.c, which is now removed */
#include <stdio.h>
#include <string.h>
#include "internal/cryptlib.h"
#include <openssl/stack.h>
#include <openssl/lhash.h>
#include <openssl/conf.h>
#include <openssl/conf_api.h>
#include "conf_def.h"
#include <openssl/buffer.h>
#include <openssl/err.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 char *eat_ws(CONF *conf, char *p);
static char *eat_alpha_numeric(CONF *conf, char *p);
static void clear_comments(CONF *conf, char *p);
static int str_copy(CONF *conf, char *section, char **to, char *from);
static char *scan_quote(CONF *conf, char *p);
static char *scan_dquote(CONF *conf, char *p);
#define scan_esc(conf,p) (((IS_EOF((conf),(p)[1]))?((p)+1):((p)+2)))
static CONF *def_create(CONF_METHOD *meth);
static int def_init_default(CONF *conf);
static int def_init_WIN32(CONF *conf);
static int def_destroy(CONF *conf);
static int def_destroy_data(CONF *conf);
static int def_load(CONF *conf, const char *name, long *eline);
static int def_load_bio(CONF *conf, BIO *bp, long *eline);
static int def_dump(const CONF *conf, BIO *bp);
static int def_is_number(const CONF *conf, char c);
static int def_to_int(const CONF *conf, char c);
static CONF_METHOD default_method = {
"OpenSSL default",
def_create,
def_init_default,
def_destroy,
def_destroy_data,
def_load_bio,
def_dump,
def_is_number,
def_to_int,
def_load
};
static CONF_METHOD WIN32_method = {
"WIN32",
def_create,
def_init_WIN32,
def_destroy,
def_destroy_data,
def_load_bio,
def_dump,
def_is_number,
def_to_int,
def_load
};
CONF_METHOD *NCONF_default()
{
return &default_method;
}
CONF_METHOD *NCONF_WIN32()
{
return &WIN32_method;
}
static CONF *def_create(CONF_METHOD *meth)
{
CONF *ret;
ret = OPENSSL_malloc(sizeof(*ret));
if (ret != NULL)
if (meth->init(ret) == 0) {
OPENSSL_free(ret);
ret = NULL;
}
return ret;
}
static int def_init_default(CONF *conf)
{
if (conf == NULL)
return 0;
conf->meth = &default_method;
conf->meth_data = (void *)CONF_type_default;
conf->data = NULL;
return 1;
}
static int def_init_WIN32(CONF *conf)
{
if (conf == NULL)
return 0;
conf->meth = &WIN32_method;
conf->meth_data = (void *)CONF_type_win32;
conf->data = NULL;
return 1;
}
static int def_destroy(CONF *conf)
{
if (def_destroy_data(conf)) {
OPENSSL_free(conf);
return 1;
}
return 0;
}
static int def_destroy_data(CONF *conf)
{
if (conf == NULL)
return 0;
_CONF_free_data(conf);
return 1;
}
static int def_load(CONF *conf, const char *name, long *line)
{
int ret;
BIO *in = NULL;
#ifdef OPENSSL_SYS_VMS
in = BIO_new_file(name, "r");
#else
in = BIO_new_file(name, "rb");
#endif
if (in == NULL) {
if (ERR_GET_REASON(ERR_peek_last_error()) == BIO_R_NO_SUCH_FILE)
CONFerr(CONF_F_DEF_LOAD, CONF_R_NO_SUCH_FILE);
else
CONFerr(CONF_F_DEF_LOAD, ERR_R_SYS_LIB);
return 0;
}
ret = def_load_bio(conf, in, line);
BIO_free(in);
return ret;
}
static int def_load_bio(CONF *conf, BIO *in, long *line)
{
/* The macro BUFSIZE conflicts with a system macro in VxWorks */
#define 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;
void *h = (void *)(conf->data);
if ((buff = BUF_MEM_new()) == NULL) {
CONFerr(CONF_F_DEF_LOAD_BIO, ERR_R_BUF_LIB);
goto err;
}
section = OPENSSL_strdup("default");
if (section == NULL) {
CONFerr(CONF_F_DEF_LOAD_BIO, ERR_R_MALLOC_FAILURE);
goto err;
}
if (_CONF_new_data(conf) == 0) {
CONFerr(CONF_F_DEF_LOAD_BIO, ERR_R_MALLOC_FAILURE);
goto err;
}
sv = _CONF_new_section(conf, section);
if (sv == NULL) {
CONFerr(CONF_F_DEF_LOAD_BIO, CONF_R_UNABLE_TO_CREATE_NEW_SECTION);
goto err;
}
bufnum = 0;
again = 0;
for (;;) {
if (!BUF_MEM_grow(buff, bufnum + CONFBUFSIZE)) {
CONFerr(CONF_F_DEF_LOAD_BIO, 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;
}
CONFerr(CONF_F_DEF_LOAD_BIO,
CONF_R_MISSING_CLOSE_SQUARE_BRACKET);
goto err;
}
*end = '\0';
if (!str_copy(conf, NULL, &section, start))
goto err;
if ((sv = _CONF_get_section(conf, section)) == NULL)
sv = _CONF_new_section(conf, section);
if (sv == NULL) {
CONFerr(CONF_F_DEF_LOAD_BIO,
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 != '=') {
CONFerr(CONF_F_DEF_LOAD_BIO, 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 = OPENSSL_malloc(sizeof(*v))) == NULL) {
CONFerr(CONF_F_DEF_LOAD_BIO, ERR_R_MALLOC_FAILURE);
goto err;
}
if (psection == NULL)
psection = section;
v->name = OPENSSL_malloc(strlen(pname) + 1);
v->value = NULL;
if (v->name == NULL) {
CONFerr(CONF_F_DEF_LOAD_BIO, ERR_R_MALLOC_FAILURE);
goto err;
}
OPENSSL_strlcpy(v->name, pname, strlen(pname) + 1);
if (!str_copy(conf, psection, &(v->value), start))
goto err;
if (strcmp(psection, section) != 0) {
if ((tv = _CONF_get_section(conf, psection))
== NULL)
tv = _CONF_new_section(conf, psection);
if (tv == NULL) {
CONFerr(CONF_F_DEF_LOAD_BIO,
CONF_R_UNABLE_TO_CREATE_NEW_SECTION);
goto err;
}
} else
tv = sv;
if (_CONF_add_string(conf, tv, v) == 0) {
CONFerr(CONF_F_DEF_LOAD_BIO, ERR_R_MALLOC_FAILURE);
goto err;
}
v = NULL;
}
}
BUF_MEM_free(buff);
OPENSSL_free(section);
return (1);
err:
BUF_MEM_free(buff);
OPENSSL_free(section);
if (line != NULL)
*line = eline;
BIO_snprintf(btmp, sizeof btmp, "%ld", eline);
ERR_add_error_data(2, "line ", btmp);
if (h != conf->data) {
CONF_free(conf->data);
conf->data = NULL;
}
if (v != NULL) {
OPENSSL_free(v->name);
OPENSSL_free(v->value);
OPENSSL_free(v);
}
return (0);
}
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 str_copy(CONF *conf, char *section, char **pto, char *from)
{
int q, r, rr = 0, to = 0, len = 0;
char *s, *e, *rp, *p, *rrp, *np, *cp, v;
BUF_MEM *buf;
if ((buf = BUF_MEM_new()) == 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 == '$') {
size_t newsize;
/* 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) {
CONFerr(CONF_F_STR_COPY, 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 = _CONF_get_string(conf, cp, np);
if (rrp != NULL)
*rrp = rr;
*rp = r;
if (p == NULL) {
CONFerr(CONF_F_STR_COPY, CONF_R_VARIABLE_HAS_NO_VALUE);
goto err;
}
newsize = strlen(p) + buf->length - (e - from);
if (newsize > MAX_CONF_VALUE_LENGTH) {
CONFerr(CONF_F_STR_COPY, CONF_R_VARIABLE_EXPANSION_TOO_LONG);
goto err;
}
if (!BUF_MEM_grow_clean(buf, newsize)) {
CONFerr(CONF_F_STR_COPY, 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';
OPENSSL_free(*pto);
*pto = buf->data;
OPENSSL_free(buf);
return (1);
err:
BUF_MEM_free(buf);
return (0);
}
static char *eat_ws(CONF *conf, char *p)
{
while (IS_WS(conf, *p) && (!IS_EOF(conf, *p)))
p++;
return (p);
}
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 dump_value_doall_arg(const CONF_VALUE *a, BIO *out)
{
if (a->name)
BIO_printf(out, "[%s] %s=%s\n", a->section, a->name, a->value);
else
BIO_printf(out, "[[%s]]\n", a->section);
}
IMPLEMENT_LHASH_DOALL_ARG_CONST(CONF_VALUE, BIO);
static int def_dump(const CONF *conf, BIO *out)
{
lh_CONF_VALUE_doall_BIO(conf->data, dump_value_doall_arg, out);
return 1;
}
static int def_is_number(const CONF *conf, char c)
{
return IS_NUMBER(conf, c);
}
static int def_to_int(const CONF *conf, char c)
{
return c - '0';
}
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