From d55812cb97e464f972c25d92282788370782438d Mon Sep 17 00:00:00 2001
From: Matt Johnston <matt@ucc.asn.au>
Date: Sat, 19 Nov 2022 20:54:43 +0800
Subject: [PATCH] Add sanity check against cleartext messages
---
src/encrypt.rs | 5 +++++
src/traffic.rs | 10 ++++++++++
2 files changed, 15 insertions(+)
diff --git a/src/encrypt.rs b/src/encrypt.rs
index d108cf3..eba4f4b 100644
--- a/src/encrypt.rs
+++ b/src/encrypt.rs
@@ -59,6 +59,11 @@ impl KeyState {
}
}
+ pub fn is_cleartext(&self) -> bool {
+ matches!(self.keys.enc, EncKey::NoCipher)
+ || matches!(self.keys.dec, DecKey::NoCipher)
+ }
+
/// Updates with new keys, keeping the same sequence numbers
pub fn rekey(&mut self, keys: Keys) {
self.keys = keys
diff --git a/src/traffic.rs b/src/traffic.rs
index f480b80..ec6f93c 100644
--- a/src/traffic.rs
+++ b/src/traffic.rs
@@ -290,6 +290,16 @@ impl<'a> TrafOut<'a> {
TxState::Write { idx, len } => (idx, len),
};
+ // Sanity check
+ match p.category() {
+ packets::Category::All | packets::Category::Kex => (), // OK cleartext
+ _ => {
+ if keys.is_cleartext() {
+ return Error::bug_msg("send cleartext")
+ }
+ }
+ }
+
// Use the remainder of our buffer to write the packet. Payload starts
// after the length and padding bytes which get filled by encrypt()
let wbuf = &mut self.buf[len..];
--
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