Fix: PR notes fixes

Author: Roy-Carter

configure.ac

@@ -10379,7 +10379,7 @@ yes) AM_CFLAGS="$AM_CFLAGS -DHAVE_EX_DATA"
 [[1-9]]|[[1-9]][[0-9]]|[[1-9]][[0-9]][[0-9]]|[[1-9]][[0-9]][[0-9]][[0-9]])
        AM_CFLAGS="$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 9999])
+*) AC_MSG_ERROR([Invalid argument to --enable-context-extra-user-data -- must be yes, no, or a number from 1 to 9999 (note: each index reserves one pointer per object, so large values increase memory use)])  
    ;;
 esac
 

wolfssl/internal.h

@@ -1444,9 +1444,13 @@ enum {
 
 #ifndef WOLFSSL_COOKIE_LEN
 /* Maximum size for a DTLS cookie */
-#define WOLFSSL_COOKIE_LEN 32 
+#define WOLFSSL_COOKIE_LEN 32
 #endif 
 
+#if WOLFSSL_COOKIE_LEN > 255
+#error "WOLFSSL_COOKIE_LEN must be <= 255 per RFC 6347 (opaque<0..2^8-1>)"
+#endif
+
 #if defined(WOLFSSL_TLS13) || !defined(NO_PSK)
 
 #define TLS13_TICKET_NONCE_MAX_SZ 255