Enhance extra user data value and external cookie length max size

configure.ac

@@ -10376,9 +10376,10 @@ case "$ENABLED_EX_DATA" in
 no) ;;
 yes) AM_CFLAGS="$AM_CFLAGS -DHAVE_EX_DATA"
      ;;
-[[1-9]]|[[1-9]][[0-9]]) AM_CFLAGS="$AM_CFLAGS -DHAVE_EX_DATA -DMAX_EX_DATA=$ENABLED_EX_DATA"
+[[1-9]]|[[1-9]][[0-9]]|[[1-9]][[0-9]][[0-9]]|[[1-9]][[0-9]][[0-9]][[0-9]])
+       AM_CFLAGS="$AM_CFLAGS -DHAVE_EX_DATA -DMAX_EX_DATA=$ENABLED_EX_DATA"
        ;;
-*) AC_MSG_ERROR([Invalid argument to --enable-context-extra-user-data -- must be yes, no, or a number from 1 to 99])
+*) AC_MSG_ERROR([Invalid argument to --enable-context-extra-user-data -- must be yes, no, or a number from 1 to 9999])
    ;;
 esac
 

wolfssl/internal.h

@@ -1569,7 +1569,7 @@ enum Misc {
     SEED_LEN     = RAN_LEN * 2, /* tls prf seed length    */
     ID_LEN       = 32,         /* session id length       */
     COOKIE_SECRET_SZ = 14,     /* dtls cookie secret size */
-    MAX_COOKIE_LEN = 32,       /* max dtls cookie size    */
+    MAX_COOKIE_LEN = 254,      /* max dtls cookie size per RFC 6347 (opaque<0..2^8-1>) more than 254 can be malformed / malicious  */
     COOKIE_SZ    = 20,         /* use a 20 byte cookie    */
     SUITE_LEN    =  2,         /* cipher suite sz length  */
     ENUM_LEN     =  1,         /* always a byte           */