diff options
author | djm@openbsd.org <djm@openbsd.org> | 2021-12-19 22:13:12 +0000 |
---|---|---|
committer | Damien Miller <djm@mindrot.org> | 2021-12-20 09:28:07 +1100 |
commit | 3e16365a79cdeb2d758cf1da6051b1c5266ceed7 (patch) | |
tree | 5045eb987548e925013a3bb89bdb021e9a3a2fb3 | |
parent | 94ae0c6f0e35903b695e033bf4beacea1d376bb1 (diff) |
upstream: EXT_INFO negotiation of hostbound pubkey auth
the EXT_INFO packet gets a new publickey-hostbound@openssh.com to
advertise the hostbound public key method.
Client side support to parse this feature flag and set the kex->flags
indicator if the expected version is offered (currently "0").
ok markus@
OpenBSD-Commit-ID: 4cdb2ca5017ec1ed7a9d33bda95c1d6a97b583b0
-rw-r--r-- | kex.c | 22 |
1 files changed, 20 insertions, 2 deletions
@@ -1,4 +1,4 @@ -/* $OpenBSD: kex.c,v 1.169 2021/12/19 22:08:06 djm Exp $ */ +/* $OpenBSD: kex.c,v 1.170 2021/12/19 22:13:12 djm Exp $ */ /* * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. * @@ -436,9 +436,12 @@ kex_send_ext_info(struct ssh *ssh) return SSH_ERR_ALLOC_FAIL; /* XXX filter algs list by allowed pubkey/hostbased types */ if ((r = sshpkt_start(ssh, SSH2_MSG_EXT_INFO)) != 0 || - (r = sshpkt_put_u32(ssh, 1)) != 0 || + (r = sshpkt_put_u32(ssh, 2)) != 0 || (r = sshpkt_put_cstring(ssh, "server-sig-algs")) != 0 || (r = sshpkt_put_cstring(ssh, algs)) != 0 || + (r = sshpkt_put_cstring(ssh, + "publickey-hostbound@openssh.com")) != 0 || + (r = sshpkt_put_cstring(ssh, "0")) != 0 || (r = sshpkt_send(ssh)) != 0) { error_fr(r, "compose"); goto out; @@ -498,6 +501,21 @@ kex_input_ext_info(int type, u_int32_t seq, struct ssh *ssh) debug_f("%s=<%s>", name, val); kex->server_sig_algs = val; val = NULL; + } else if (strcmp(name, + "publickey-hostbound@openssh.com") == 0) { + /* XXX refactor */ + /* Ensure no \0 lurking in value */ + if (memchr(val, '\0', vlen) != NULL) { + error_f("nul byte in %s", name); + return SSH_ERR_INVALID_FORMAT; + } + debug_f("%s=<%s>", name, val); + if (strcmp(val, "0") == 0) + kex->flags |= KEX_HAS_PUBKEY_HOSTBOUND; + else { + debug_f("unsupported version of %s extension", + name); + } } else debug_f("%s (unrecognised)", name); free(name); |