Validate SOCKS arguments.

This commit is contained in:
George Kadianakis 2012-12-17 14:39:24 +02:00
parent 757b03aacb
commit faf4f6c6d1
4 changed files with 83 additions and 0 deletions

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@ -4025,6 +4025,40 @@ options_init_logs(or_options_t *options, int validate_only)
return ok?0:-1;
}
/** Given a smartlist of SOCKS arguments to be passed to a transport
* proxy in <b>args</b>, validate them and return -1 if they are
* corrupted. Return 0 if they seem OK. */
static int
validate_transport_socks_arguments(const smartlist_t *args)
{
char *socks_string = NULL;
size_t socks_string_len;
tor_assert(args);
tor_assert(smartlist_len(args) > 0);
SMARTLIST_FOREACH_BEGIN(args, const char *, s) {
if (!string_is_key_value(s)) /* arguments should be k=v items */
return -1;
} SMARTLIST_FOREACH_END(s);
socks_string = pt_stringify_socks_args(args);
if (!socks_string)
return -1;
socks_string_len = strlen(socks_string);
tor_free(socks_string);
if (socks_string_len > MAX_SOCKS5_AUTH_SIZE_TOTAL) {
log_warn(LD_CONFIG, "SOCKS arguments can't be more than %u bytes (%lu).",
MAX_SOCKS5_AUTH_SIZE_TOTAL,
(unsigned long) socks_string_len);
return -1;
}
return 0;
}
/** Read the contents of a Bridge line from <b>line</b>. Return 0
* if the line is well-formed, and -1 if it isn't. If
* <b>validate_only</b> is 0, and the line is well-formed, then add
@ -4143,6 +4177,11 @@ parse_bridge_line(const char *line, int validate_only)
bridge_add_from_config(&addr, port,
fingerprint ? digest : NULL,
transport_name, socks_args);
} else {
if (socks_args) {
if (validate_transport_socks_arguments(socks_args) < 0)
goto err;
}
}
r = 0;

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@ -89,6 +89,14 @@ int connection_connect(connection_t *conn, const char *address,
const tor_addr_t *addr,
uint16_t port, int *socket_error);
/** Maximum size of information that we can fit into SOCKS5 username
or password fields. */
#define MAX_SOCKS5_AUTH_FIELD_SIZE 255
/** Total maximum size of information that we can fit into SOCKS5
username and password fields. */
#define MAX_SOCKS5_AUTH_SIZE_TOTAL 2*MAX_SOCKS5_AUTH_FIELD_SIZE
int connection_proxy_connect(connection_t *conn, int type);
int connection_read_proxy_handshake(connection_t *conn);
void log_failed_proxy_connection(connection_t *conn);

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@ -1424,6 +1424,41 @@ pt_get_extra_info_descriptor_string(void)
return the_string;
}
/** Stringify the SOCKS arguments in <b>socks_args</b> according to
* 180_pluggable_transport.txt. The string is allocated on the heap
* and it's the responsibility of the caller to free it after use. */
char *
pt_stringify_socks_args(const smartlist_t *socks_args)
{
/* tmp place to store escaped socks arguments, so that we can
concatenate them up afterwards */
smartlist_t *sl_tmp = NULL;
char *escaped_string = NULL;
char *new_string = NULL;
tor_assert(socks_args);
tor_assert(smartlist_len(socks_args) > 0);
sl_tmp = smartlist_new();
SMARTLIST_FOREACH_BEGIN(socks_args, const char *, s) {
/* Escape ';' and '\'. */
escaped_string = tor_escape_str_for_socks_arg(s);
if (!escaped_string)
goto done;
smartlist_add(sl_tmp, escaped_string);
} SMARTLIST_FOREACH_END(s);
new_string = smartlist_join_strings(sl_tmp, ";", 0, NULL);
done:
SMARTLIST_FOREACH(sl_tmp, char *, s, tor_free(s));
smartlist_free(sl_tmp);
return new_string;
}
/** The tor config was read.
* Destroy all managed proxies that were marked by a previous call to
* prepare_proxy_list_for_config_read() and are not used by the new

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@ -55,6 +55,7 @@ void pt_prepare_proxy_list_for_config_read(void);
void sweep_proxy_list(void);
smartlist_t *get_transport_proxy_ports(void);
char *pt_stringify_socks_args(const smartlist_t *socks_args);
#ifdef PT_PRIVATE
/** State of the managed proxy configuration protocol. */