Update the GPL boilerplate with the new address of the FSF.

[freeradius.git] / src / modules / rlm_otp / otp_site.c

diff --git a/src/modules/rlm_otp/otp_site.c b/src/modules/rlm_otp/otp_site.c
index ed04567..d8b92f2 100644 (file)
--- a/src/modules/rlm_otp/otp_site.c
+++ b/src/modules/rlm_otp/otp_site.c
@@ -14,10 +14,10 @@
  *
  *   You should have received a copy of the GNU General Public License
  *   along with this program; if not, write to the Free Software
- *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  *
  * Copyright 2001,2002  Google, Inc.
- * Copyright 2005 TRI-D Systems, Inc.
+ * Copyright 2005,2006 TRI-D Systems, Inc.
  */
 
 /*
@@ -27,9 +27,6 @@
  * - implement a site-specific transform of the challenge, and/or
  * - only allow async mode from secure locations.
  *
- * Note that you cannot easily just disallow async mode completely
- * as you typically must provide a way to resynchronize the token.
- *
  * Please read the accompanying docs for more info.
  *
  * IMPORTANT  IMPORTANT  IMPORTANT  IMPORTANT  IMPORTANT  IMPORTANT
@@ -41,15 +38,28 @@
 static const char rcsid[] = "$Id$";
 
 
-int
-otp_challenge_transform(
-#ifdef __GNUC__
-__attribute__ ((unused))
-#endif
-                        const char *username,
-                        char challenge[OTP_MAX_CHALLENGE_LEN + 1])
+/*
+ * The default transform appends the first 2 username chars to the
+ * challenge.  This results in a challenge that generally cannot be
+ * entered on any supported token, thus forcing a site-specific
+ * implementation to support async mode.
+ */
+ssize_t
+otp_challenge_transform(const char *username,
+                        unsigned char challenge[OTP_MAX_CHALLENGE_LEN],
+                        size_t clen)
 {
-  (void) strcpy(challenge, "DISABLED");
-  return 0;
-}
+  /* overwrite challenge in-place if not enough room */
+  switch (OTP_MAX_CHALLENGE_LEN - clen) {
+    case 0: clen -= 2; break;
+    case 1: clen -= 1; break;
+  }
+
+  /* append first 2 username chars to challenge */
+  if (*username)
+    challenge[clen++] = *username++;
+  if (*username)
+    challenge[clen++] = *username++;
 
+  return clen;
+}