path: root/authfd.c
diff options
mode: <>2019-06-21 04:21:04 +0000
committerDamien Miller <>2019-06-21 14:24:35 +1000
commit4f7a56d5e02e3d04ab69eac1213817a7536d0562 (patch)
treeb17da67f20831b53f9b00c6647c5eb1bdf88d626 /authfd.c
parent4cd6b12cc9c10bf59c8b425041f3ea5091285a0f (diff)
upstream: Add protection for private keys at rest in RAM against
speculation and memory sidechannel attacks like Spectre, Meltdown, Rowhammer and Rambleed. This change encrypts private keys when they are not in use with a symmetic key that is derived from a relatively large "prekey" consisting of random data (currently 16KB). Attackers must recover the entire prekey with high accuracy before they can attempt to decrypt the shielded private key, but the current generation of attacks have bit error rates that, when applied cumulatively to the entire prekey, make this unlikely. Implementation-wise, keys are encrypted "shielded" when loaded and then automatically and transparently unshielded when used for signatures or when being saved/serialised. Hopefully we can remove this in a few years time when computer architecture has become less unsafe. been in snaps for a bit already; thanks deraadt@ ok dtucker@ deraadt@ OpenBSD-Commit-ID: 19767213c312e46f94b303a512ef8e9218a39bd4
Diffstat (limited to 'authfd.c')
1 files changed, 2 insertions, 2 deletions
diff --git a/authfd.c b/authfd.c
index 95348abf..327a333d 100644
--- a/authfd.c
+++ b/authfd.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: authfd.c,v 1.113 2018/12/27 23:02:11 djm Exp $ */
+/* $OpenBSD: authfd.c,v 1.114 2019/06/21 04:21:04 djm Exp $ */
* Author: Tatu Ylonen <>
* Copyright (c) 1995 Tatu Ylonen <>, Espoo, Finland
@@ -423,7 +423,7 @@ encode_constraints(struct sshbuf *m, u_int life, u_int confirm, u_int maxsign)
* This call is intended only for use by ssh-add(1) and like applications.
-ssh_add_identity_constrained(int sock, const struct sshkey *key,
+ssh_add_identity_constrained(int sock, struct sshkey *key,
const char *comment, u_int life, u_int confirm, u_int maxsign)
struct sshbuf *msg;