[Openswan dev] bug in openswan-2.1.0rc1/programs/pluto/whack.c

[Niki Waibel]

problem:

if i use x509 certs and keypairs with passphrases + %prompt in /etc/ipsec.secrets
the passphrase is never accepted.
===
# ipsec auto --rereadsecrets
040 need passphrase for '/etc/ipsec.d/private/testKey.pem'
Secret enter: 
003 no passphrase entered, aborted
003 "/etc/ipsec.secrets" line 2: error loading RSA private key file
040 need passphrase for '/etc/ipsec.d/private/testKey.pem'
Secret enter: 
sh: line 4:  1061 Segmentation fault      ipsec whack --rereadsecrets
===



analysis:

the problematic function is get_secret. you can find it in
./programs/pluto/whack.c. it seems that this part:
===
                        case RC_ENTERSECRET:
                            if(!gotxauthpass)
                            {
                                xauthpasslen = get_secret(xauthpass
                                                          , sizeof(xauthpass));
                            }
===
is wrong. it is a bit stange to me that the var ``xauthpass'' is used. i am
not using the XAUTH feature ... anyway, sizeof(xauthpass) seems to be zero...

i think this should be:
xauthpasslen = get_secret(xauthpass, 128);

and -- the funktion itself should look like this:
===
static size_t
get_secret(char *buf, size_t bufsize)
{
    const char *secret;
    int len;

    fflush(stdout);
    usleep(20000); /* give fflush time for flushing */
    secret = getpass("Secret enter: ");
    secret = (secret == NULL) ? "" : secret;

    strncpy(buf, secret, bufsize);

    len = strlen(buf) + 1;

    return len;
}
===



patch:

===
diff -u -r openswan-2.1.0rc1.orig/programs/pluto/whack.c openswan-2.1.0rc1/programs/pluto/whack.c
--- openswan-2.1.0rc1.orig/programs/pluto/whack.c       2004-02-09 23:00:53.000000000 +0100
+++ openswan-2.1.0rc1/programs/pluto/whack.c    2004-03-19 17:05:34.313319440 +0100
@@ -666,8 +666,8 @@
 
     fflush(stdout);
     usleep(20000); /* give fflush time for flushing */
-    buf = getpass("Secret enter: ");
-    secret = (buf == NULL)? "" : buf;
+    secret = getpass("Secret enter: ");
+    secret = (secret == NULL) ? "" : secret;
 
     strncpy(buf, secret, bufsize);
 
@@ -1651,7 +1651,7 @@
                            if(!gotxauthpass)
                            {
                                xauthpasslen = get_secret(xauthpass
-                                                         , sizeof(xauthpass));
+                                                         , 128);
                            }
                            send_reply(sock, xauthpass, xauthpasslen);
                            break;
===



in addition:
===
GETPASS(3)                 Linux Programmer's Manual                GETPASS(3)
NAME
       getpass - get a password
SYNOPSIS
       #include <unistd.h>
       char *getpass( const char * prompt );
DESCRIPTION
       This function is obsolete. Do not use it.
       The  getpass() function opens /dev/tty (the controlling terminal of the
       process), outputs the string prompt, turns off echoing, reads one  line
       (the  "password"),  restores  the  terminal  state  and closes /dev/tty
       again.
===
note ---> ``This function is obsolete. Do not use it.''



hope this helps, niki