From e838ba44150ecbd4b1f78582b470915d172fa05c Mon Sep 17 00:00:00 2001 From: djm Date: Sun, 29 Aug 2021 23:53:10 +0000 Subject: [PATCH] After years of forewarning, disable the RSA/SHA-1 signature algorithm by default. It is feasible to create colliding SHA1 hashes, so we need to deprecate its use. RSA/SHA-256/512 remains available and will be transparently selected instead of RSA/SHA1 for most SSH servers released in the last five+ years. There is no need to regenerate RSA keys. The use of RSA/SHA1 can be re-enabled by adding "ssh-rsa" to the PubkeyAcceptedAlgorithms directives on the client and server. ok dtucker deraadt --- usr.bin/ssh/myproposal.h | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/usr.bin/ssh/myproposal.h b/usr.bin/ssh/myproposal.h index f03b7dfd0df..6d79937b6fa 100644 --- a/usr.bin/ssh/myproposal.h +++ b/usr.bin/ssh/myproposal.h @@ -1,4 +1,4 @@ -/* $OpenBSD: myproposal.h,v 1.68 2020/10/03 04:15:06 djm Exp $ */ +/* $OpenBSD: myproposal.h,v 1.69 2021/08/29 23:53:10 djm Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. @@ -46,7 +46,6 @@ "sk-ecdsa-sha2-nistp256-cert-v01@openssh.com," \ "rsa-sha2-512-cert-v01@openssh.com," \ "rsa-sha2-256-cert-v01@openssh.com," \ - "ssh-rsa-cert-v01@openssh.com," \ "ssh-ed25519," \ "ecdsa-sha2-nistp256," \ "ecdsa-sha2-nistp384," \ @@ -54,8 +53,7 @@ "sk-ssh-ed25519@openssh.com," \ "sk-ecdsa-sha2-nistp256@openssh.com," \ "rsa-sha2-512," \ - "rsa-sha2-256," \ - "ssh-rsa" + "rsa-sha2-256" #define KEX_SERVER_ENCRYPT \ "chacha20-poly1305@openssh.com," \ -- 2.20.1