diff options
| author | Damien Miller <djm@cvs.openbsd.org> | 2020-01-25 00:06:49 +0000 |
|---|---|---|
| committer | Damien Miller <djm@cvs.openbsd.org> | 2020-01-25 00:06:49 +0000 |
| commit | 201a77d860e4bc3171d344453d28799c14827b24 (patch) | |
| tree | bdeb9fa1a923b26813c27bf9afd9294c1e05531b /usr.bin | |
| parent | 85c9568845c5930d5ce54984e4dbe8ced31c5ddc (diff) | |
process security key provider via realpath() in agent, avoids
malicious client from being able to cause agent to load arbitrary
libraries into ssh-sk-helper.
reported by puck AT puckipedia.com; ok markus
Diffstat (limited to 'usr.bin')
| -rw-r--r-- | usr.bin/ssh/ssh-agent.c | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/usr.bin/ssh/ssh-agent.c b/usr.bin/ssh/ssh-agent.c index af50b8237f0..5d31edb8ea5 100644 --- a/usr.bin/ssh/ssh-agent.c +++ b/usr.bin/ssh/ssh-agent.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ssh-agent.c,v 1.253 2020/01/25 00:03:36 djm Exp $ */ +/* $OpenBSD: ssh-agent.c,v 1.254 2020/01/25 00:06:48 djm Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland @@ -416,6 +416,7 @@ process_add_identity(SocketEntry *e) int success = 0, confirm = 0; u_int seconds, maxsign; char *fp, *comment = NULL, *ext_name = NULL, *sk_provider = NULL; + char canonical_provider[PATH_MAX]; time_t death = 0; struct sshkey *k = NULL; u_char ctype; @@ -500,14 +501,25 @@ process_add_identity(SocketEntry *e) free(sk_provider); goto send; } - if (strcasecmp(sk_provider, "internal") == 0) + if (strcasecmp(sk_provider, "internal") == 0) { debug("%s: internal provider", __func__); - else if (match_pattern_list(sk_provider, - provider_whitelist, 0) != 1) { - error("Refusing add key: provider %s not whitelisted", - sk_provider); + } else { + if (realpath(sk_provider, canonical_provider) == NULL) { + verbose("failed provider \"%.100s\": " + "realpath: %s", sk_provider, + strerror(errno)); + free(sk_provider); + goto send; + } free(sk_provider); - goto send; + sk_provider = xstrdup(canonical_provider); + if (match_pattern_list(sk_provider, + provider_whitelist, 0) != 1) { + error("Refusing add key: " + "provider %s not whitelisted", sk_provider); + free(sk_provider); + goto send; + } } } if ((r = sshkey_shield_private(k)) != 0) { |