OpenVPN auth-pam plugin patch for password concatenation delimiting on rightmost comma (meant to be used with Duo Security's OpenVPN plugin)

auth-pam.patch

--- auth-pam.c.bak	2012-01-19 11:39:38.728363546 -0600
+++ auth-pam.c	2012-01-20 14:11:35.718361562 -0600
@@ -548,6 +548,28 @@
   int ret = PAM_SUCCESS;
 
   *response_array = NULL;
+  char *p;
+  p = strrchr(up->password, ',');
+
+  /* dont process nothing or any string longer then 7 characters */
+  if (p == NULL)
+  {
+      fprintf(stderr, "ERROR: your 2nd password is null\n");
+      return (PAM_CONV_ERR);
+  } else if ((strlen(p)) > 8 )
+  {
+      fprintf(stderr, "ERROR: your 2nd password is too long\n"); 
+      return (PAM_CONV_ERR);
+  }
+
+  /*fprintf(stderr, "DEBUG: strrchr split: %s\n", p);*/
+
+  /* intentionally leaving newpass 1 byte larger so its null terminated */
+  char newpass[(strlen(up->password)) - (strlen(p)-1)];
+  memset(newpass, 0, sizeof(newpass));
+  strncpy(newpass, up->password, (strlen(up->password)-1)-(strlen(p)-1));
+  memset((void *)up->password, 0, sizeof(up->password));
+  strncpy((void *)up->password, newpass, sizeof(newpass));
 
   if (n <= 0 || n > PAM_MAX_NUM_MSG)
     return (PAM_CONV_ERR);