1 files changed, 13 insertions, 0 deletions
diff --git a/src/handshake/messages.rs b/src/handshake/messages.rs
index 8611609..796e3c0 100644
--- a/src/handshake/messages.rs
+++ b/src/handshake/messages.rs
@@ -4,6 +4,9 @@ use hex;
 #[cfg(test)]
 use std::fmt;
 
+use std::cmp;
+use std::mem;
+
 use byteorder::LittleEndian;
 use zerocopy::byteorder::U32;
 use zerocopy::{AsBytes, ByteSlice, FromBytes, LayoutVerified};
@@ -21,6 +24,16 @@ pub const TYPE_INITIATION: u32 = 1;
 pub const TYPE_RESPONSE: u32 = 2;
 pub const TYPE_COOKIE_REPLY: u32 = 3;
 
+const fn max(a: usize, b: usize) -> usize {
+    let m: usize = (a > b) as usize;
+    m * a + (1 - m) * b
+}
+
+pub const MAX_HANDSHAKE_MSG_SIZE: usize = max(
+    max(mem::size_of::<Response>(), mem::size_of::<Initiation>()),
+    mem::size_of::<CookieReply>(),
+);
+
 /* Handshake messsages */
 
 #[repr(packed)]