From 95becaaf3b65d6227a41f4cb3f0f114bcfbe5562 Mon Sep 17 00:00:00 2001 From: Robert Pluim Date: Mon, 2 Sep 2019 14:55:00 +0200 Subject: [PATCH] Don't check for :safe-renegotiation with TLS1.3 * lisp/net/nsm.el (nsm-protocol-check--renegotiation-info-ext): Don't check when using TLS1.3, renegotiation has been removed from TLS. Reported in --- lisp/net/nsm.el | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/lisp/net/nsm.el b/lisp/net/nsm.el index 8750c19267a..2121fdeb519 100644 --- a/lisp/net/nsm.el +++ b/lisp/net/nsm.el @@ -665,17 +665,19 @@ the MD5 Message-Digest and the HMAC-MD5 Algorithms\", If this TLS extension is not used, the connection established is vulnerable to an attack in which an impersonator can extract sensitive information such as HTTP session ID cookies or login -passwords. +passwords. Renegotiation was removed in TLS1.3, so this is only +checked for earlier protocol versions. Reference: E. Rescorla, M. Ray, S. Dispensa, N. Oskov (Feb 2010). \"Transport Layer Security (TLS) Renegotiation Indication Extension\", `https://tools.ietf.org/html/rfc5746'" - (let ((unsafe-renegotiation (not (plist-get status :safe-renegotiation)))) - (and unsafe-renegotiation - (format-message - "safe renegotiation is not supported, connection not protected from impersonators")))) + (when (plist-member status :safe-renegotiation) + (let ((unsafe-renegotiation (not (plist-get status :safe-renegotiation)))) + (and unsafe-renegotiation + (format-message + "safe renegotiation is not supported, connection not protected from impersonators"))))) ;; Compression checks -- 2.39.2