diff options
Diffstat (limited to 'usr.bin/ssh/serverloop.c')
| -rw-r--r-- | usr.bin/ssh/serverloop.c | 88 |
1 files changed, 84 insertions, 4 deletions
diff --git a/usr.bin/ssh/serverloop.c b/usr.bin/ssh/serverloop.c index d46459d4309..6b09fbde2f5 100644 --- a/usr.bin/ssh/serverloop.c +++ b/usr.bin/ssh/serverloop.c @@ -1,4 +1,4 @@ -/* $OpenBSD: serverloop.c,v 1.176 2015/01/20 23:14:00 deraadt Exp $ */ +/* $OpenBSD: serverloop.c,v 1.177 2015/02/16 22:13:32 djm Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland @@ -75,6 +75,7 @@ #include "auth-options.h" #include "serverloop.h" #include "roaming.h" +#include "ssherr.h" extern ServerOptions options; @@ -1113,11 +1114,82 @@ server_input_channel_open(int type, u_int32_t seq, void *ctxt) } static int +server_input_hostkeys_prove(struct sshbuf **respp) +{ + struct ssh *ssh = active_state; /* XXX */ + struct sshbuf *resp = NULL; + struct sshbuf *sigbuf = NULL; + struct sshkey *key = NULL, *key_pub = NULL, *key_prv = NULL; + int r, ndx, success = 0; + const u_char *blob; + u_char *sig = 0; + size_t blen, slen; + + if ((resp = sshbuf_new()) == NULL || (sigbuf = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); + + while (ssh_packet_remaining(ssh) > 0) { + sshkey_free(key); + key = NULL; + if ((r = sshpkt_get_string_direct(ssh, &blob, &blen)) != 0 || + (r = sshkey_from_blob(blob, blen, &key)) != 0) { + error("%s: couldn't parse key: %s", + __func__, ssh_err(r)); + goto out; + } + /* + * Better check that this is actually one of our hostkeys + * before attempting to sign anything with it. + */ + if ((ndx = ssh->kex->host_key_index(key, 1, ssh)) == -1) { + error("%s: unknown host %s key", + __func__, sshkey_type(key)); + goto out; + } + /* + * XXX refactor: make kex->sign just use an index rather + * than passing in public and private keys + */ + if ((key_prv = get_hostkey_by_index(ndx)) == NULL && + (key_pub = get_hostkey_public_by_index(ndx, ssh)) == NULL) { + error("%s: can't retrieve hostkey %d", __func__, ndx); + goto out; + } + sshbuf_reset(sigbuf); + free(sig); + sig = NULL; + if ((r = sshbuf_put_string(sigbuf, + ssh->kex->session_id, ssh->kex->session_id_len)) != 0 || + (r = sshbuf_put_cstring(sigbuf, + "hostkeys-prove@openssh.com")) != 0 || + (r = sshkey_puts(key, sigbuf)) != 0 || + (r = ssh->kex->sign(key_prv, key_pub, &sig, &slen, + sshbuf_ptr(sigbuf), sshbuf_len(sigbuf), 0)) != 0 || + (r = sshbuf_put_string(resp, sig, slen)) != 0) { + error("%s: couldn't prepare signature: %s", + __func__, ssh_err(r)); + goto out; + } + } + /* Success */ + *respp = resp; + resp = NULL; /* don't free it */ + success = 1; + out: + free(sig); + sshbuf_free(resp); + sshbuf_free(sigbuf); + sshkey_free(key); + return success; +} + +static int server_input_global_request(int type, u_int32_t seq, void *ctxt) { char *rtype; int want_reply; - int success = 0, allocated_listen_port = 0; + int r, success = 0, allocated_listen_port = 0; + struct sshbuf *resp = NULL; rtype = packet_get_string(NULL); want_reply = packet_get_char(); @@ -1151,6 +1223,10 @@ server_input_global_request(int type, u_int32_t seq, void *ctxt) &allocated_listen_port, &options.fwd_opts); } free(fwd.listen_host); + if ((resp = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); + if ((r = sshbuf_put_u32(resp, allocated_listen_port)) != 0) + fatal("%s: sshbuf_put_u32: %s", __func__, ssh_err(r)); } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) { struct Forward fwd; @@ -1194,16 +1270,20 @@ server_input_global_request(int type, u_int32_t seq, void *ctxt) } else if (strcmp(rtype, "no-more-sessions@openssh.com") == 0) { no_more_sessions = 1; success = 1; + } else if (strcmp(rtype, "hostkeys-prove@openssh.com") == 0) { + success = server_input_hostkeys_prove(&resp); } if (want_reply) { packet_start(success ? SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); - if (success && allocated_listen_port > 0) - packet_put_int(allocated_listen_port); + if (success && resp != NULL) + ssh_packet_put_raw(active_state, sshbuf_ptr(resp), + sshbuf_len(resp)); packet_send(); packet_write_wait(); } free(rtype); + sshbuf_free(resp); return 0; } |