diff options
| -rw-r--r-- | usr.bin/ssh/kex.c | 31 | ||||
| -rw-r--r-- | usr.bin/ssh/sshconnect2.c | 21 | ||||
| -rw-r--r-- | usr.bin/ssh/sshd.c | 4 |
3 files changed, 35 insertions, 21 deletions
diff --git a/usr.bin/ssh/kex.c b/usr.bin/ssh/kex.c index 050d0df1001..1e9ad51d882 100644 --- a/usr.bin/ssh/kex.c +++ b/usr.bin/ssh/kex.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kex.c,v 1.184 2023/12/18 14:45:49 djm Exp $ */ +/* $OpenBSD: kex.c,v 1.185 2024/01/08 00:34:33 djm Exp $ */ /* * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. * @@ -757,10 +757,11 @@ static int kex_input_newkeys(int type, u_int32_t seq, struct ssh *ssh) { struct kex *kex = ssh->kex; - int r; + int r, initial = (kex->flags & KEX_INITIAL) != 0; + char *cp, **prop; debug("SSH2_MSG_NEWKEYS received"); - if (kex->ext_info_c && (kex->flags & KEX_INITIAL) != 0) + if (kex->ext_info_c && initial) ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &kex_input_ext_info); ssh_dispatch_set(ssh, SSH2_MSG_NEWKEYS, &kex_protocol_error); ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, &kex_input_kexinit); @@ -768,10 +769,32 @@ kex_input_newkeys(int type, u_int32_t seq, struct ssh *ssh) return r; if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0) return r; + if (initial) { + /* Remove initial KEX signalling from proposal for rekeying */ + if ((r = kex_buf2prop(kex->my, NULL, &prop)) != 0) + return r; + if ((cp = match_filter_denylist(prop[PROPOSAL_KEX_ALGS], + kex->server ? + "ext-info-s,kex-strict-s-v00@openssh.com" : + "ext-info-c,kex-strict-c-v00@openssh.com")) == NULL) { + error_f("match_filter_denylist failed"); + goto fail; + } + free(prop[PROPOSAL_KEX_ALGS]); + prop[PROPOSAL_KEX_ALGS] = cp; + if ((r = kex_prop2buf(ssh->kex->my, prop)) != 0) { + error_f("kex_prop2buf failed"); + fail: + kex_proposal_free_entries(prop); + free(prop); + return SSH_ERR_INTERNAL_ERROR; + } + kex_proposal_free_entries(prop); + free(prop); + } kex->done = 1; kex->flags &= ~KEX_INITIAL; sshbuf_reset(kex->peer); - /* sshbuf_reset(kex->my); */ kex->flags &= ~KEX_INIT_SENT; free(kex->name); kex->name = NULL; diff --git a/usr.bin/ssh/sshconnect2.c b/usr.bin/ssh/sshconnect2.c index dead8d5d19c..020a0f6effb 100644 --- a/usr.bin/ssh/sshconnect2.c +++ b/usr.bin/ssh/sshconnect2.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sshconnect2.c,v 1.371 2023/12/18 14:45:49 djm Exp $ */ +/* $OpenBSD: sshconnect2.c,v 1.372 2024/01/08 00:34:34 djm Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. * Copyright (c) 2008 Damien Miller. All rights reserved. @@ -216,7 +216,7 @@ ssh_kex2(struct ssh *ssh, char *host, struct sockaddr *hostaddr, u_short port, const struct ssh_conn_info *cinfo) { char *myproposal[PROPOSAL_MAX]; - char *s, *all_key, *hkalgs = NULL; + char *all_key, *hkalgs = NULL; int r, use_known_hosts_order = 0; xxx_host = host; @@ -244,14 +244,12 @@ ssh_kex2(struct ssh *ssh, char *host, struct sockaddr *hostaddr, u_short port, fatal_fr(r, "kex_assemble_namelist"); free(all_key); - if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL) - fatal_f("kex_names_cat"); - if (use_known_hosts_order) hkalgs = order_hostkeyalgs(host, hostaddr, port, cinfo); - kex_proposal_populate_entries(ssh, myproposal, s, options.ciphers, - options.macs, compression_alg_list(options.compression), + kex_proposal_populate_entries(ssh, myproposal, + options.kex_algorithms, options.ciphers, options.macs, + compression_alg_list(options.compression), hkalgs ? hkalgs : options.hostkeyalgorithms); free(hkalgs); @@ -274,13 +272,7 @@ ssh_kex2(struct ssh *ssh, char *host, struct sockaddr *hostaddr, u_short port, ssh->kex->verify_host_key=&verify_host_key_callback; ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &ssh->kex->done); - - /* remove ext-info from the KEX proposals for rekeying */ - free(myproposal[PROPOSAL_KEX_ALGS]); - myproposal[PROPOSAL_KEX_ALGS] = - compat_kex_proposal(ssh, options.kex_algorithms); - if ((r = kex_prop2buf(ssh->kex->my, myproposal)) != 0) - fatal_r(r, "kex_prop2buf"); + kex_proposal_free_entries(myproposal); #ifdef DEBUG_KEXDH /* send 1st encrypted/maced/compressed message */ @@ -290,7 +282,6 @@ ssh_kex2(struct ssh *ssh, char *host, struct sockaddr *hostaddr, u_short port, (r = ssh_packet_write_wait(ssh)) != 0) fatal_fr(r, "send packet"); #endif - kex_proposal_free_entries(myproposal); } /* diff --git a/usr.bin/ssh/sshd.c b/usr.bin/ssh/sshd.c index 04b450efd03..a5d56e9fa01 100644 --- a/usr.bin/ssh/sshd.c +++ b/usr.bin/ssh/sshd.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sshd.c,v 1.601 2023/12/18 14:45:49 djm Exp $ */ +/* $OpenBSD: sshd.c,v 1.602 2024/01/08 00:34:34 djm Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland @@ -2261,6 +2261,7 @@ do_ssh2_kex(struct ssh *ssh) kex->sign = sshd_hostkey_sign; ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &kex->done); + kex_proposal_free_entries(myproposal); #ifdef DEBUG_KEXDH /* send 1st encrypted/maced/compressed message */ @@ -2270,7 +2271,6 @@ do_ssh2_kex(struct ssh *ssh) (r = ssh_packet_write_wait(ssh)) != 0) fatal_fr(r, "send test"); #endif - kex_proposal_free_entries(myproposal); debug("KEX done"); } |