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|
00-sslauth.patch by Artur R. Czechowski <arturcz@hell.pl>
http://sourceforge.net/support/tracker.php?aid=1744566
This patch allows ssl-enabled clients to connect to
non-ssl-enabled servers and vice versa. It also enables use
of /dev/random based encryption instead of C's built-in
(and rather weak) rand() function.
Index: vtun-3.0.3/auth.c
===================================================================
--- vtun-3.0.3.orig/auth.c 2012-10-07 20:22:53.425321705 +0200
+++ vtun-3.0.3/auth.c 2012-10-07 20:41:25.545351485 +0200
@@ -23,6 +23,10 @@
/*
* Challenge based authentication.
* Thanx to Chris Todd<christ@insynq.com> for the good idea.
+ *
+ * Artur R. Czechowski <arturcz@hell.pl>, 02/17/2002
+ * Add support for connectin ssl to non-ssl vtuns (sslauth option)
+ * Use /dev/random in non-ssl gen_chal (if possible)
*/
#include "config.h"
@@ -55,34 +59,57 @@
#include "lock.h"
#include "auth.h"
-/* Encryption and Decryption of the challenge key */
#ifdef HAVE_SSL
#include <openssl/md5.h>
#include <openssl/blowfish.h>
#include <openssl/rand.h>
+#endif /* HAVE_SSL */
+
+/* Okay, start the "blue-wire" non-ssl auth patch stuff */
+static void nonssl_encrypt_chal(char *chal, char *pwd)
+{
+ char *xor_msk = pwd;
+ register int i, xor_len = strlen(xor_msk);
+
+ syslog(LOG_INFO, "Use nonSSL-aware challenge/response");
+ for(i=0; i < VTUN_CHAL_SIZE; i++)
+ chal[i] ^= xor_msk[i%xor_len];
+}
+
+static inline void nonssl_decrypt_chal(char *chal, char *pwd)
+{
+ nonssl_encrypt_chal(chal, pwd);
+}
+/* Mostly ended here, other than a couple replaced #ifdefs */
+
+/* Encryption and Decryption of the challenge-key */
+#ifdef HAVE_SSL
+
static void gen_chal(char *buf)
{
RAND_bytes(buf, VTUN_CHAL_SIZE);
}
-static void encrypt_chal(char *chal, char *pwd)
+static void ssl_encrypt_chal(char *chal, char *pwd)
{
register int i;
BF_KEY key;
+ syslog(LOG_INFO, "Use SSL-aware challenge/response");
BF_set_key(&key, 16, MD5(pwd,strlen(pwd),NULL));
for(i=0; i < VTUN_CHAL_SIZE; i += 8 )
BF_ecb_encrypt(chal + i, chal + i, &key, BF_ENCRYPT);
}
-static void decrypt_chal(char *chal, char *pwd)
+static void ssl_decrypt_chal(char *chal, char *pwd)
{
register int i;
BF_KEY key;
+ syslog(LOG_INFO, "Use SSL-aware challenge/response");
BF_set_key(&key, 16, MD5(pwd,strlen(pwd),NULL));
for(i=0; i < VTUN_CHAL_SIZE; i += 8 )
@@ -91,30 +118,43 @@
#else /* HAVE_SSL */
-static void encrypt_chal(char *chal, char *pwd)
-{
- char * xor_msk = pwd;
- register int i, xor_len = strlen(xor_msk);
-
- for(i=0; i < VTUN_CHAL_SIZE; i++)
- chal[i] ^= xor_msk[i%xor_len];
-}
-
-static void inline decrypt_chal(char *chal, char *pwd)
-{
- encrypt_chal(chal, pwd);
-}
-
/* Generate PSEUDO random challenge key. */
static void gen_chal(char *buf)
{
register int i;
-
- srand(time(NULL));
+ unsigned int seed;
+ char *pseed;
+ int fd,cnt,len;
+
+ if((fd=open("/dev/random",O_RDONLY))!=-1) {
+ pseed=(char *)&seed;
+ len=cnt=sizeof(seed);
+ while(cnt>0) {
+ cnt=read(fd,pseed,len);
+ len=len-cnt;
+ pseed=pseed+cnt;
+ }
+ } else {
+ seed=time(NULL);
+ }
+ srand(seed);
for(i=0; i < VTUN_CHAL_SIZE; i++)
buf[i] = (unsigned int)(255.0 * rand()/RAND_MAX);
}
+
+static void ssl_encrypt_chal(char *chal, char *pwd)
+{
+ syslog(LOG_ERR,"Cannot use `sslauth yes' without SSL support - fallback to `sslauth no'");
+ nonssl_encrypt_chal(chal,pwd);
+}
+
+static void ssl_decrypt_chal(char *chal, char *pwd)
+{
+ syslog(LOG_ERR,"Cannot use `sslauth yes' without SSL support - fallback to `sslauth no'");
+ nonssl_decrypt_chal(chal,pwd);
+}
+
#endif /* HAVE_SSL */
/*
@@ -358,7 +398,11 @@
if( !(h = find_host(host)) )
break;
- decrypt_chal(chal_res, h->passwd);
+ if (h->sslauth) {
+ ssl_decrypt_chal(chal_res, h->passwd);
+ } else {
+ nonssl_decrypt_chal(chal_res, h->passwd);
+ }
if( !memcmp(chal_req, chal_res, VTUN_CHAL_SIZE) ){
/* Auth successeful. */
@@ -410,7 +454,11 @@
if( !strncmp(buf,"OK",2) && cs2cl(buf,chal)){
stage = ST_CHAL;
- encrypt_chal(chal,host->passwd);
+ if (host->sslauth) {
+ ssl_encrypt_chal(chal,host->passwd);
+ } else {
+ nonssl_encrypt_chal(chal,host->passwd);
+ }
print_p(fd,"CHAL: %s\n", cl2cs(chal));
continue;
Index: vtun-3.0.3/cfg_file.y
===================================================================
--- vtun-3.0.3.orig/cfg_file.y 2012-10-07 20:22:53.425321705 +0200
+++ vtun-3.0.3/cfg_file.y 2012-10-07 20:41:25.545351485 +0200
@@ -74,7 +74,7 @@
%token K_OPTIONS K_DEFAULT K_PORT K_BINDADDR K_PERSIST K_TIMEOUT
%token K_PASSWD K_PROG K_PPP K_SPEED K_IFCFG K_FWALL K_ROUTE K_DEVICE
%token K_MULTI K_SRCADDR K_IFACE K_ADDR
-%token K_TYPE K_PROT K_NAT_HACK K_COMPRESS K_ENCRYPT K_KALIVE K_STAT
+%token K_TYPE K_PROT K_NAT_HACK K_COMPRESS K_ENCRYPT K_KALIVE K_STAT K_SSLAUTH
%token K_UP K_DOWN K_SYSLOG K_IPROUTE
%token <str> K_HOST K_ERROR
@@ -284,6 +284,13 @@
}
compress
+ | K_SSLAUTH NUM {
+ parse_host->sslauth = $2;
+
+ if(vtun.sslauth == -1)
+ vtun.sslauth = $2;
+ }
+
| K_ENCRYPT NUM {
if( $2 ){
parse_host->flags |= VTUN_ENCRYPT;
Index: vtun-3.0.3/cfg_kwords.h
===================================================================
--- vtun-3.0.3.orig/cfg_kwords.h 2012-10-07 20:22:53.425321705 +0200
+++ vtun-3.0.3/cfg_kwords.h 2012-10-07 20:41:25.545351485 +0200
@@ -37,6 +37,7 @@
{ "addr", K_ADDR },
{ "iface", K_IFACE },
{ "bindaddr", K_BINDADDR },
+ { "sslauth", K_SSLAUTH },
{ "persist", K_PERSIST },
{ "multi", K_MULTI },
{ "iface", K_IFACE },
Index: vtun-3.0.3/main.c
===================================================================
--- vtun-3.0.3.orig/main.c 2012-10-07 20:22:53.425321705 +0200
+++ vtun-3.0.3/main.c 2012-10-07 20:41:25.549351485 +0200
@@ -66,6 +66,7 @@
vtun.cfg_file = VTUN_CONFIG_FILE;
vtun.persist = -1;
vtun.timeout = -1;
+ vtun.sslauth = -1;
/* Dup strings because parser will try to free them */
vtun.ppp = strdup("/usr/sbin/pppd");
@@ -88,6 +89,11 @@
default_host.ka_interval = 30;
default_host.ka_maxfail = 4;
default_host.loc_fd = default_host.rmt_fd = -1;
+#ifdef HAVE_SSL
+ default_host.sslauth = 1;
+#else /* HAVE_SSL */
+ default_host.sslauth = 0;
+#endif /* HAVE_SSL */
/* Start logging to syslog and stderr */
openlog("vtund", LOG_PID | LOG_NDELAY | LOG_PERROR, LOG_DAEMON);
@@ -166,6 +172,16 @@
vtun.persist = 0;
if(vtun.timeout == -1)
vtun.timeout = VTUN_TIMEOUT;
+ /*
+ * Want to save behaviour from older version: stronger authentication
+ * if compiled with --enable-ssl, weaker otherwise
+ */
+ if(vtun.sslauth == -1)
+#ifdef HAVE_SSL
+ vtun.sslauth = 1;
+#else /* HAVE_SSL */
+ vtun.sslauth = 0;
+#endif /* HAVE_SSL */
switch( vtun.svr_type ){
case -1:
Index: vtun-3.0.3/vtun.h
===================================================================
--- vtun-3.0.3.orig/vtun.h 2012-10-07 20:22:53.425321705 +0200
+++ vtun-3.0.3/vtun.h 2012-10-07 20:41:25.549351485 +0200
@@ -99,6 +99,9 @@
int rmt_fd;
int loc_fd;
+ /* SSL strong auth */
+ int sslauth;
+
/* Persist mode */
int persist;
@@ -204,6 +207,7 @@
struct vtun_opts {
int timeout;
int persist;
+ int sslauth;
char *cfg_file;
|