mirror of
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2a7e344990
to set this was removed in OpenSSH 7.7 when support for SSH implementations dating back to before RFC standardization were removed. "burn it all" djm@ OpenBSD-Commit-ID: 6330935fbe23dd00be79891505e06d1ffdac7cda
1951 lines
52 KiB
C
1951 lines
52 KiB
C
/* $OpenBSD: monitor.c,v 1.235 2023/02/17 04:22:50 dtucker Exp $ */
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/*
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* Copyright 2002 Niels Provos <provos@citi.umich.edu>
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* Copyright 2002 Markus Friedl <markus@openbsd.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "includes.h"
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <sys/wait.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <limits.h>
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#ifdef HAVE_PATHS_H
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#include <paths.h>
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#endif
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#include <pwd.h>
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#include <signal.h>
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#ifdef HAVE_STDINT_H
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# include <stdint.h>
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#endif
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#include <stdlib.h>
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#include <string.h>
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#include <stdarg.h>
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#include <stdio.h>
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#include <unistd.h>
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#ifdef HAVE_POLL_H
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#include <poll.h>
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#else
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# ifdef HAVE_SYS_POLL_H
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# include <sys/poll.h>
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# endif
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#endif
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#ifdef WITH_OPENSSL
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#include <openssl/dh.h>
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#endif
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#include "openbsd-compat/sys-tree.h"
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#include "openbsd-compat/sys-queue.h"
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#include "openbsd-compat/openssl-compat.h"
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#include "atomicio.h"
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#include "xmalloc.h"
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#include "ssh.h"
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#include "sshkey.h"
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#include "sshbuf.h"
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#include "hostfile.h"
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#include "auth.h"
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#include "cipher.h"
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#include "kex.h"
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#include "dh.h"
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#include "auth-pam.h"
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#include "packet.h"
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#include "auth-options.h"
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#include "sshpty.h"
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#include "channels.h"
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#include "session.h"
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#include "sshlogin.h"
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#include "canohost.h"
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#include "log.h"
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#include "misc.h"
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#include "servconf.h"
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#include "monitor.h"
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#ifdef GSSAPI
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#include "ssh-gss.h"
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#endif
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#include "monitor_wrap.h"
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#include "monitor_fdpass.h"
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#include "compat.h"
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#include "ssh2.h"
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#include "authfd.h"
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#include "match.h"
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#include "ssherr.h"
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#include "sk-api.h"
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#ifdef GSSAPI
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static Gssctxt *gsscontext = NULL;
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#endif
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/* Imports */
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extern ServerOptions options;
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extern u_int utmp_len;
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extern struct sshbuf *loginmsg;
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extern struct sshauthopt *auth_opts; /* XXX move to permanent ssh->authctxt? */
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/* State exported from the child */
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static struct sshbuf *child_state;
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/* Functions on the monitor that answer unprivileged requests */
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int mm_answer_moduli(struct ssh *, int, struct sshbuf *);
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int mm_answer_sign(struct ssh *, int, struct sshbuf *);
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int mm_answer_pwnamallow(struct ssh *, int, struct sshbuf *);
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int mm_answer_auth2_read_banner(struct ssh *, int, struct sshbuf *);
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int mm_answer_authserv(struct ssh *, int, struct sshbuf *);
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int mm_answer_authpassword(struct ssh *, int, struct sshbuf *);
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int mm_answer_bsdauthquery(struct ssh *, int, struct sshbuf *);
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int mm_answer_bsdauthrespond(struct ssh *, int, struct sshbuf *);
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int mm_answer_keyallowed(struct ssh *, int, struct sshbuf *);
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int mm_answer_keyverify(struct ssh *, int, struct sshbuf *);
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int mm_answer_pty(struct ssh *, int, struct sshbuf *);
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int mm_answer_pty_cleanup(struct ssh *, int, struct sshbuf *);
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int mm_answer_term(struct ssh *, int, struct sshbuf *);
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int mm_answer_rsa_keyallowed(struct ssh *, int, struct sshbuf *);
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int mm_answer_rsa_challenge(struct ssh *, int, struct sshbuf *);
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int mm_answer_rsa_response(struct ssh *, int, struct sshbuf *);
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int mm_answer_sesskey(struct ssh *, int, struct sshbuf *);
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int mm_answer_sessid(struct ssh *, int, struct sshbuf *);
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#ifdef USE_PAM
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int mm_answer_pam_start(struct ssh *, int, struct sshbuf *);
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int mm_answer_pam_account(struct ssh *, int, struct sshbuf *);
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int mm_answer_pam_init_ctx(struct ssh *, int, struct sshbuf *);
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int mm_answer_pam_query(struct ssh *, int, struct sshbuf *);
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int mm_answer_pam_respond(struct ssh *, int, struct sshbuf *);
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int mm_answer_pam_free_ctx(struct ssh *, int, struct sshbuf *);
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#endif
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#ifdef GSSAPI
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int mm_answer_gss_setup_ctx(struct ssh *, int, struct sshbuf *);
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int mm_answer_gss_accept_ctx(struct ssh *, int, struct sshbuf *);
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int mm_answer_gss_userok(struct ssh *, int, struct sshbuf *);
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int mm_answer_gss_checkmic(struct ssh *, int, struct sshbuf *);
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#endif
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#ifdef SSH_AUDIT_EVENTS
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int mm_answer_audit_event(struct ssh *, int, struct sshbuf *);
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int mm_answer_audit_command(struct ssh *, int, struct sshbuf *);
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#endif
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static Authctxt *authctxt;
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/* local state for key verify */
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static u_char *key_blob = NULL;
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static size_t key_bloblen = 0;
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static u_int key_blobtype = MM_NOKEY;
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static struct sshauthopt *key_opts = NULL;
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static char *hostbased_cuser = NULL;
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static char *hostbased_chost = NULL;
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static char *auth_method = "unknown";
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static char *auth_submethod = NULL;
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static u_int session_id2_len = 0;
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static u_char *session_id2 = NULL;
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static pid_t monitor_child_pid;
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struct mon_table {
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enum monitor_reqtype type;
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int flags;
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int (*f)(struct ssh *, int, struct sshbuf *);
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};
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#define MON_ISAUTH 0x0004 /* Required for Authentication */
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#define MON_AUTHDECIDE 0x0008 /* Decides Authentication */
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#define MON_ONCE 0x0010 /* Disable after calling */
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#define MON_ALOG 0x0020 /* Log auth attempt without authenticating */
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#define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE)
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#define MON_PERMIT 0x1000 /* Request is permitted */
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static int monitor_read(struct ssh *, struct monitor *, struct mon_table *,
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struct mon_table **);
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static int monitor_read_log(struct monitor *);
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struct mon_table mon_dispatch_proto20[] = {
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#ifdef WITH_OPENSSL
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{MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
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#endif
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{MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
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{MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
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{MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
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{MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
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{MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
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#ifdef USE_PAM
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{MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
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{MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
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{MONITOR_REQ_PAM_INIT_CTX, MON_ONCE, mm_answer_pam_init_ctx},
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{MONITOR_REQ_PAM_QUERY, 0, mm_answer_pam_query},
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{MONITOR_REQ_PAM_RESPOND, MON_ONCE, mm_answer_pam_respond},
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{MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
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#endif
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#ifdef SSH_AUDIT_EVENTS
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{MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
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#endif
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#ifdef BSD_AUTH
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{MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
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{MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
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#endif
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{MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
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{MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
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#ifdef GSSAPI
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{MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
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{MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx},
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{MONITOR_REQ_GSSUSEROK, MON_ONCE|MON_AUTHDECIDE, mm_answer_gss_userok},
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{MONITOR_REQ_GSSCHECKMIC, MON_ONCE, mm_answer_gss_checkmic},
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#endif
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{0, 0, NULL}
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};
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struct mon_table mon_dispatch_postauth20[] = {
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#ifdef WITH_OPENSSL
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{MONITOR_REQ_MODULI, 0, mm_answer_moduli},
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#endif
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{MONITOR_REQ_SIGN, 0, mm_answer_sign},
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{MONITOR_REQ_PTY, 0, mm_answer_pty},
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{MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
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{MONITOR_REQ_TERM, 0, mm_answer_term},
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#ifdef SSH_AUDIT_EVENTS
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{MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
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{MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command},
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#endif
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{0, 0, NULL}
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};
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struct mon_table *mon_dispatch;
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/* Specifies if a certain message is allowed at the moment */
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static void
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monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
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{
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while (ent->f != NULL) {
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if (ent->type == type) {
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ent->flags &= ~MON_PERMIT;
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ent->flags |= permit ? MON_PERMIT : 0;
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return;
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}
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ent++;
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}
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}
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static void
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monitor_permit_authentications(int permit)
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{
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struct mon_table *ent = mon_dispatch;
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while (ent->f != NULL) {
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if (ent->flags & MON_AUTH) {
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ent->flags &= ~MON_PERMIT;
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ent->flags |= permit ? MON_PERMIT : 0;
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}
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ent++;
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}
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}
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void
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monitor_child_preauth(struct ssh *ssh, struct monitor *pmonitor)
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{
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struct mon_table *ent;
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int authenticated = 0, partial = 0;
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debug3("preauth child monitor started");
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if (pmonitor->m_recvfd >= 0)
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close(pmonitor->m_recvfd);
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if (pmonitor->m_log_sendfd >= 0)
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close(pmonitor->m_log_sendfd);
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pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1;
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authctxt = (Authctxt *)ssh->authctxt;
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memset(authctxt, 0, sizeof(*authctxt));
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ssh->authctxt = authctxt;
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authctxt->loginmsg = loginmsg;
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mon_dispatch = mon_dispatch_proto20;
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/* Permit requests for moduli and signatures */
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monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
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monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
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/* The first few requests do not require asynchronous access */
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while (!authenticated) {
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partial = 0;
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auth_method = "unknown";
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auth_submethod = NULL;
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auth2_authctxt_reset_info(authctxt);
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authenticated = (monitor_read(ssh, pmonitor,
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mon_dispatch, &ent) == 1);
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/* Special handling for multiple required authentications */
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if (options.num_auth_methods != 0) {
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if (authenticated &&
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!auth2_update_methods_lists(authctxt,
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auth_method, auth_submethod)) {
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debug3_f("method %s: partial", auth_method);
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authenticated = 0;
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partial = 1;
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}
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}
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if (authenticated) {
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if (!(ent->flags & MON_AUTHDECIDE))
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fatal_f("unexpected authentication from %d",
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ent->type);
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if (authctxt->pw->pw_uid == 0 &&
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!auth_root_allowed(ssh, auth_method))
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authenticated = 0;
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#ifdef USE_PAM
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/* PAM needs to perform account checks after auth */
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if (options.use_pam && authenticated) {
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struct sshbuf *m;
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if ((m = sshbuf_new()) == NULL)
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fatal("%s: sshbuf_new failed",
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__func__);
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mm_request_receive_expect(pmonitor->m_sendfd,
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MONITOR_REQ_PAM_ACCOUNT, m);
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authenticated = mm_answer_pam_account(
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ssh, pmonitor->m_sendfd, m);
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sshbuf_free(m);
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}
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#endif
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}
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if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
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auth_log(ssh, authenticated, partial,
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auth_method, auth_submethod);
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if (!partial && !authenticated)
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authctxt->failures++;
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if (authenticated || partial) {
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auth2_update_session_info(authctxt,
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auth_method, auth_submethod);
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}
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}
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}
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if (!authctxt->valid)
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fatal_f("authenticated invalid user");
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if (strcmp(auth_method, "unknown") == 0)
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fatal_f("authentication method name unknown");
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debug_f("user %s authenticated by privileged process", authctxt->user);
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ssh->authctxt = NULL;
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ssh_packet_set_log_preamble(ssh, "user %s", authctxt->user);
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mm_get_keystate(ssh, pmonitor);
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/* Drain any buffered messages from the child */
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while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0)
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;
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if (pmonitor->m_recvfd >= 0)
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close(pmonitor->m_recvfd);
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if (pmonitor->m_log_sendfd >= 0)
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close(pmonitor->m_log_sendfd);
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pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1;
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}
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static void
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monitor_set_child_handler(pid_t pid)
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{
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monitor_child_pid = pid;
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}
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static void
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monitor_child_handler(int sig)
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{
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kill(monitor_child_pid, sig);
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}
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void
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monitor_child_postauth(struct ssh *ssh, struct monitor *pmonitor)
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{
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close(pmonitor->m_recvfd);
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pmonitor->m_recvfd = -1;
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monitor_set_child_handler(pmonitor->m_pid);
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ssh_signal(SIGHUP, &monitor_child_handler);
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ssh_signal(SIGTERM, &monitor_child_handler);
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ssh_signal(SIGINT, &monitor_child_handler);
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#ifdef SIGXFSZ
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ssh_signal(SIGXFSZ, SIG_IGN);
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#endif
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mon_dispatch = mon_dispatch_postauth20;
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/* Permit requests for moduli and signatures */
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monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
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monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
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monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
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if (auth_opts->permit_pty_flag) {
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monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
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monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
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}
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for (;;)
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monitor_read(ssh, pmonitor, mon_dispatch, NULL);
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}
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static int
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monitor_read_log(struct monitor *pmonitor)
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{
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struct sshbuf *logmsg;
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u_int len, level, forced;
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char *msg;
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u_char *p;
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int r;
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if ((logmsg = sshbuf_new()) == NULL)
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fatal_f("sshbuf_new");
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/* Read length */
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if ((r = sshbuf_reserve(logmsg, 4, &p)) != 0)
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fatal_fr(r, "reserve len");
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if (atomicio(read, pmonitor->m_log_recvfd, p, 4) != 4) {
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if (errno == EPIPE) {
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sshbuf_free(logmsg);
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debug_f("child log fd closed");
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close(pmonitor->m_log_recvfd);
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pmonitor->m_log_recvfd = -1;
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return -1;
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}
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fatal_f("log fd read: %s", strerror(errno));
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}
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if ((r = sshbuf_get_u32(logmsg, &len)) != 0)
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fatal_fr(r, "parse len");
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if (len <= 4 || len > 8192)
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fatal_f("invalid log message length %u", len);
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/* Read severity, message */
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sshbuf_reset(logmsg);
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if ((r = sshbuf_reserve(logmsg, len, &p)) != 0)
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fatal_fr(r, "reserve msg");
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if (atomicio(read, pmonitor->m_log_recvfd, p, len) != len)
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fatal_f("log fd read: %s", strerror(errno));
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if ((r = sshbuf_get_u32(logmsg, &level)) != 0 ||
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(r = sshbuf_get_u32(logmsg, &forced)) != 0 ||
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(r = sshbuf_get_cstring(logmsg, &msg, NULL)) != 0)
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fatal_fr(r, "parse");
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/* Log it */
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if (log_level_name(level) == NULL)
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fatal_f("invalid log level %u (corrupted message?)", level);
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sshlogdirect(level, forced, "%s [preauth]", msg);
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sshbuf_free(logmsg);
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free(msg);
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return 0;
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}
|
|
|
|
static int
|
|
monitor_read(struct ssh *ssh, struct monitor *pmonitor, struct mon_table *ent,
|
|
struct mon_table **pent)
|
|
{
|
|
struct sshbuf *m;
|
|
int r, ret;
|
|
u_char type;
|
|
struct pollfd pfd[2];
|
|
|
|
for (;;) {
|
|
memset(&pfd, 0, sizeof(pfd));
|
|
pfd[0].fd = pmonitor->m_sendfd;
|
|
pfd[0].events = POLLIN;
|
|
pfd[1].fd = pmonitor->m_log_recvfd;
|
|
pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN;
|
|
if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) {
|
|
if (errno == EINTR || errno == EAGAIN)
|
|
continue;
|
|
fatal_f("poll: %s", strerror(errno));
|
|
}
|
|
if (pfd[1].revents) {
|
|
/*
|
|
* Drain all log messages before processing next
|
|
* monitor request.
|
|
*/
|
|
monitor_read_log(pmonitor);
|
|
continue;
|
|
}
|
|
if (pfd[0].revents)
|
|
break; /* Continues below */
|
|
}
|
|
|
|
if ((m = sshbuf_new()) == NULL)
|
|
fatal_f("sshbuf_new");
|
|
|
|
mm_request_receive(pmonitor->m_sendfd, m);
|
|
if ((r = sshbuf_get_u8(m, &type)) != 0)
|
|
fatal_fr(r, "parse type");
|
|
|
|
debug3_f("checking request %d", type);
|
|
|
|
while (ent->f != NULL) {
|
|
if (ent->type == type)
|
|
break;
|
|
ent++;
|
|
}
|
|
|
|
if (ent->f != NULL) {
|
|
if (!(ent->flags & MON_PERMIT))
|
|
fatal_f("unpermitted request %d", type);
|
|
ret = (*ent->f)(ssh, pmonitor->m_sendfd, m);
|
|
sshbuf_free(m);
|
|
|
|
/* The child may use this request only once, disable it */
|
|
if (ent->flags & MON_ONCE) {
|
|
debug2_f("%d used once, disabling now", type);
|
|
ent->flags &= ~MON_PERMIT;
|
|
}
|
|
|
|
if (pent != NULL)
|
|
*pent = ent;
|
|
|
|
return ret;
|
|
}
|
|
|
|
fatal_f("unsupported request: %d", type);
|
|
|
|
/* NOTREACHED */
|
|
return (-1);
|
|
}
|
|
|
|
/* allowed key state */
|
|
static int
|
|
monitor_allowed_key(const u_char *blob, u_int bloblen)
|
|
{
|
|
/* make sure key is allowed */
|
|
if (key_blob == NULL || key_bloblen != bloblen ||
|
|
timingsafe_bcmp(key_blob, blob, key_bloblen))
|
|
return (0);
|
|
return (1);
|
|
}
|
|
|
|
static void
|
|
monitor_reset_key_state(void)
|
|
{
|
|
/* reset state */
|
|
free(key_blob);
|
|
free(hostbased_cuser);
|
|
free(hostbased_chost);
|
|
sshauthopt_free(key_opts);
|
|
key_blob = NULL;
|
|
key_bloblen = 0;
|
|
key_blobtype = MM_NOKEY;
|
|
key_opts = NULL;
|
|
hostbased_cuser = NULL;
|
|
hostbased_chost = NULL;
|
|
}
|
|
|
|
#ifdef WITH_OPENSSL
|
|
int
|
|
mm_answer_moduli(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
DH *dh;
|
|
const BIGNUM *dh_p, *dh_g;
|
|
int r;
|
|
u_int min, want, max;
|
|
|
|
if ((r = sshbuf_get_u32(m, &min)) != 0 ||
|
|
(r = sshbuf_get_u32(m, &want)) != 0 ||
|
|
(r = sshbuf_get_u32(m, &max)) != 0)
|
|
fatal_fr(r, "parse");
|
|
|
|
debug3_f("got parameters: %d %d %d", min, want, max);
|
|
/* We need to check here, too, in case the child got corrupted */
|
|
if (max < min || want < min || max < want)
|
|
fatal_f("bad parameters: %d %d %d", min, want, max);
|
|
|
|
sshbuf_reset(m);
|
|
|
|
dh = choose_dh(min, want, max);
|
|
if (dh == NULL) {
|
|
if ((r = sshbuf_put_u8(m, 0)) != 0)
|
|
fatal_fr(r, "assemble empty");
|
|
return (0);
|
|
} else {
|
|
/* Send first bignum */
|
|
DH_get0_pqg(dh, &dh_p, NULL, &dh_g);
|
|
if ((r = sshbuf_put_u8(m, 1)) != 0 ||
|
|
(r = sshbuf_put_bignum2(m, dh_p)) != 0 ||
|
|
(r = sshbuf_put_bignum2(m, dh_g)) != 0)
|
|
fatal_fr(r, "assemble");
|
|
|
|
DH_free(dh);
|
|
}
|
|
mm_request_send(sock, MONITOR_ANS_MODULI, m);
|
|
return (0);
|
|
}
|
|
#endif
|
|
|
|
int
|
|
mm_answer_sign(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
extern int auth_sock; /* XXX move to state struct? */
|
|
struct sshkey *key;
|
|
struct sshbuf *sigbuf = NULL;
|
|
u_char *p = NULL, *signature = NULL;
|
|
char *alg = NULL;
|
|
size_t datlen, siglen, alglen;
|
|
int r, is_proof = 0;
|
|
u_int keyid, compat;
|
|
const char proof_req[] = "hostkeys-prove-00@openssh.com";
|
|
|
|
debug3_f("entering");
|
|
|
|
if ((r = sshbuf_get_u32(m, &keyid)) != 0 ||
|
|
(r = sshbuf_get_string(m, &p, &datlen)) != 0 ||
|
|
(r = sshbuf_get_cstring(m, &alg, &alglen)) != 0 ||
|
|
(r = sshbuf_get_u32(m, &compat)) != 0)
|
|
fatal_fr(r, "parse");
|
|
if (keyid > INT_MAX)
|
|
fatal_f("invalid key ID");
|
|
|
|
/*
|
|
* Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes),
|
|
* SHA384 (48 bytes) and SHA512 (64 bytes).
|
|
*
|
|
* Otherwise, verify the signature request is for a hostkey
|
|
* proof.
|
|
*
|
|
* XXX perform similar check for KEX signature requests too?
|
|
* it's not trivial, since what is signed is the hash, rather
|
|
* than the full kex structure...
|
|
*/
|
|
if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) {
|
|
/*
|
|
* Construct expected hostkey proof and compare it to what
|
|
* the client sent us.
|
|
*/
|
|
if (session_id2_len == 0) /* hostkeys is never first */
|
|
fatal_f("bad data length: %zu", datlen);
|
|
if ((key = get_hostkey_public_by_index(keyid, ssh)) == NULL)
|
|
fatal_f("no hostkey for index %d", keyid);
|
|
if ((sigbuf = sshbuf_new()) == NULL)
|
|
fatal_f("sshbuf_new");
|
|
if ((r = sshbuf_put_cstring(sigbuf, proof_req)) != 0 ||
|
|
(r = sshbuf_put_string(sigbuf, session_id2,
|
|
session_id2_len)) != 0 ||
|
|
(r = sshkey_puts(key, sigbuf)) != 0)
|
|
fatal_fr(r, "assemble private key proof");
|
|
if (datlen != sshbuf_len(sigbuf) ||
|
|
memcmp(p, sshbuf_ptr(sigbuf), sshbuf_len(sigbuf)) != 0)
|
|
fatal_f("bad data length: %zu, hostkey proof len %zu",
|
|
datlen, sshbuf_len(sigbuf));
|
|
sshbuf_free(sigbuf);
|
|
is_proof = 1;
|
|
}
|
|
|
|
/* save session id, it will be passed on the first call */
|
|
if (session_id2_len == 0) {
|
|
session_id2_len = datlen;
|
|
session_id2 = xmalloc(session_id2_len);
|
|
memcpy(session_id2, p, session_id2_len);
|
|
}
|
|
|
|
if ((key = get_hostkey_by_index(keyid)) != NULL) {
|
|
if ((r = sshkey_sign(key, &signature, &siglen, p, datlen, alg,
|
|
options.sk_provider, NULL, compat)) != 0)
|
|
fatal_fr(r, "sign");
|
|
} else if ((key = get_hostkey_public_by_index(keyid, ssh)) != NULL &&
|
|
auth_sock > 0) {
|
|
if ((r = ssh_agent_sign(auth_sock, key, &signature, &siglen,
|
|
p, datlen, alg, compat)) != 0)
|
|
fatal_fr(r, "agent sign");
|
|
} else
|
|
fatal_f("no hostkey from index %d", keyid);
|
|
|
|
debug3_f("%s %s signature len=%zu", alg,
|
|
is_proof ? "hostkey proof" : "KEX", siglen);
|
|
|
|
sshbuf_reset(m);
|
|
if ((r = sshbuf_put_string(m, signature, siglen)) != 0)
|
|
fatal_fr(r, "assemble");
|
|
|
|
free(alg);
|
|
free(p);
|
|
free(signature);
|
|
|
|
mm_request_send(sock, MONITOR_ANS_SIGN, m);
|
|
|
|
/* Turn on permissions for getpwnam */
|
|
monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
|
|
|
|
return (0);
|
|
}
|
|
|
|
#define PUTPW(b, id) \
|
|
do { \
|
|
if ((r = sshbuf_put_string(b, \
|
|
&pwent->id, sizeof(pwent->id))) != 0) \
|
|
fatal_fr(r, "assemble %s", #id); \
|
|
} while (0)
|
|
|
|
/* Retrieves the password entry and also checks if the user is permitted */
|
|
int
|
|
mm_answer_pwnamallow(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
struct passwd *pwent;
|
|
int r, allowed = 0;
|
|
u_int i;
|
|
|
|
debug3_f("entering");
|
|
|
|
if (authctxt->attempt++ != 0)
|
|
fatal_f("multiple attempts for getpwnam");
|
|
|
|
if ((r = sshbuf_get_cstring(m, &authctxt->user, NULL)) != 0)
|
|
fatal_fr(r, "parse");
|
|
|
|
pwent = getpwnamallow(ssh, authctxt->user);
|
|
|
|
setproctitle("%s [priv]", pwent ? authctxt->user : "unknown");
|
|
|
|
sshbuf_reset(m);
|
|
|
|
if (pwent == NULL) {
|
|
if ((r = sshbuf_put_u8(m, 0)) != 0)
|
|
fatal_fr(r, "assemble fakepw");
|
|
authctxt->pw = fakepw();
|
|
goto out;
|
|
}
|
|
|
|
allowed = 1;
|
|
authctxt->pw = pwent;
|
|
authctxt->valid = 1;
|
|
|
|
/* XXX send fake class/dir/shell, etc. */
|
|
if ((r = sshbuf_put_u8(m, 1)) != 0)
|
|
fatal_fr(r, "assemble ok");
|
|
PUTPW(m, pw_uid);
|
|
PUTPW(m, pw_gid);
|
|
#ifdef HAVE_STRUCT_PASSWD_PW_CHANGE
|
|
PUTPW(m, pw_change);
|
|
#endif
|
|
#ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE
|
|
PUTPW(m, pw_expire);
|
|
#endif
|
|
if ((r = sshbuf_put_cstring(m, pwent->pw_name)) != 0 ||
|
|
(r = sshbuf_put_cstring(m, "*")) != 0 ||
|
|
#ifdef HAVE_STRUCT_PASSWD_PW_GECOS
|
|
(r = sshbuf_put_cstring(m, pwent->pw_gecos)) != 0 ||
|
|
#endif
|
|
#ifdef HAVE_STRUCT_PASSWD_PW_CLASS
|
|
(r = sshbuf_put_cstring(m, pwent->pw_class)) != 0 ||
|
|
#endif
|
|
(r = sshbuf_put_cstring(m, pwent->pw_dir)) != 0 ||
|
|
(r = sshbuf_put_cstring(m, pwent->pw_shell)) != 0)
|
|
fatal_fr(r, "assemble pw");
|
|
|
|
out:
|
|
ssh_packet_set_log_preamble(ssh, "%suser %s",
|
|
authctxt->valid ? "authenticating" : "invalid ", authctxt->user);
|
|
if ((r = sshbuf_put_string(m, &options, sizeof(options))) != 0)
|
|
fatal_fr(r, "assemble options");
|
|
|
|
#define M_CP_STROPT(x) do { \
|
|
if (options.x != NULL && \
|
|
(r = sshbuf_put_cstring(m, options.x)) != 0) \
|
|
fatal_fr(r, "assemble %s", #x); \
|
|
} while (0)
|
|
#define M_CP_STRARRAYOPT(x, nx) do { \
|
|
for (i = 0; i < options.nx; i++) { \
|
|
if ((r = sshbuf_put_cstring(m, options.x[i])) != 0) \
|
|
fatal_fr(r, "assemble %s", #x); \
|
|
} \
|
|
} while (0)
|
|
/* See comment in servconf.h */
|
|
COPY_MATCH_STRING_OPTS();
|
|
#undef M_CP_STROPT
|
|
#undef M_CP_STRARRAYOPT
|
|
|
|
/* Create valid auth method lists */
|
|
if (auth2_setup_methods_lists(authctxt) != 0) {
|
|
/*
|
|
* The monitor will continue long enough to let the child
|
|
* run to its packet_disconnect(), but it must not allow any
|
|
* authentication to succeed.
|
|
*/
|
|
debug_f("no valid authentication method lists");
|
|
}
|
|
|
|
debug3_f("sending MONITOR_ANS_PWNAM: %d", allowed);
|
|
mm_request_send(sock, MONITOR_ANS_PWNAM, m);
|
|
|
|
/* Allow service/style information on the auth context */
|
|
monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
|
|
monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
|
|
|
|
#ifdef USE_PAM
|
|
if (options.use_pam)
|
|
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
|
|
#endif
|
|
|
|
return (0);
|
|
}
|
|
|
|
int mm_answer_auth2_read_banner(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
char *banner;
|
|
int r;
|
|
|
|
sshbuf_reset(m);
|
|
banner = auth2_read_banner();
|
|
if ((r = sshbuf_put_cstring(m, banner != NULL ? banner : "")) != 0)
|
|
fatal_fr(r, "assemble");
|
|
mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
|
|
free(banner);
|
|
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
mm_answer_authserv(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
int r;
|
|
|
|
monitor_permit_authentications(1);
|
|
|
|
if ((r = sshbuf_get_cstring(m, &authctxt->service, NULL)) != 0 ||
|
|
(r = sshbuf_get_cstring(m, &authctxt->style, NULL)) != 0)
|
|
fatal_fr(r, "parse");
|
|
debug3_f("service=%s, style=%s", authctxt->service, authctxt->style);
|
|
|
|
if (strlen(authctxt->style) == 0) {
|
|
free(authctxt->style);
|
|
authctxt->style = NULL;
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Check that the key type appears in the supplied pattern list, ignoring
|
|
* mismatches in the signature algorithm. (Signature algorithm checks are
|
|
* performed in the unprivileged authentication code).
|
|
* Returns 1 on success, 0 otherwise.
|
|
*/
|
|
static int
|
|
key_base_type_match(const char *method, const struct sshkey *key,
|
|
const char *list)
|
|
{
|
|
char *s, *l, *ol = xstrdup(list);
|
|
int found = 0;
|
|
|
|
l = ol;
|
|
for ((s = strsep(&l, ",")); s && *s != '\0'; (s = strsep(&l, ","))) {
|
|
if (sshkey_type_from_name(s) == key->type) {
|
|
found = 1;
|
|
break;
|
|
}
|
|
}
|
|
if (!found) {
|
|
error("%s key type %s is not in permitted list %s", method,
|
|
sshkey_ssh_name(key), list);
|
|
}
|
|
|
|
free(ol);
|
|
return found;
|
|
}
|
|
|
|
int
|
|
mm_answer_authpassword(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
static int call_count;
|
|
char *passwd;
|
|
int r, authenticated;
|
|
size_t plen;
|
|
|
|
if (!options.password_authentication)
|
|
fatal_f("password authentication not enabled");
|
|
if ((r = sshbuf_get_cstring(m, &passwd, &plen)) != 0)
|
|
fatal_fr(r, "parse");
|
|
/* Only authenticate if the context is valid */
|
|
authenticated = options.password_authentication &&
|
|
auth_password(ssh, passwd);
|
|
freezero(passwd, plen);
|
|
|
|
sshbuf_reset(m);
|
|
if ((r = sshbuf_put_u32(m, authenticated)) != 0)
|
|
fatal_fr(r, "assemble");
|
|
#ifdef USE_PAM
|
|
if ((r = sshbuf_put_u32(m, sshpam_get_maxtries_reached())) != 0)
|
|
fatal_fr(r, "assemble PAM");
|
|
#endif
|
|
|
|
debug3("%s: sending result %d", __func__, authenticated);
|
|
debug3_f("sending result %d", authenticated);
|
|
mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
|
|
|
|
call_count++;
|
|
if (plen == 0 && call_count == 1)
|
|
auth_method = "none";
|
|
else
|
|
auth_method = "password";
|
|
|
|
/* Causes monitor loop to terminate if authenticated */
|
|
return (authenticated);
|
|
}
|
|
|
|
#ifdef BSD_AUTH
|
|
int
|
|
mm_answer_bsdauthquery(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
char *name, *infotxt;
|
|
u_int numprompts, *echo_on, success;
|
|
char **prompts;
|
|
int r;
|
|
|
|
if (!options.kbd_interactive_authentication)
|
|
fatal_f("kbd-int authentication not enabled");
|
|
success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
|
|
&prompts, &echo_on) < 0 ? 0 : 1;
|
|
|
|
sshbuf_reset(m);
|
|
if ((r = sshbuf_put_u32(m, success)) != 0)
|
|
fatal_fr(r, "assemble");
|
|
if (success) {
|
|
if ((r = sshbuf_put_cstring(m, prompts[0])) != 0)
|
|
fatal_fr(r, "assemble prompt");
|
|
}
|
|
|
|
debug3_f("sending challenge success: %u", success);
|
|
mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
|
|
|
|
if (success) {
|
|
free(name);
|
|
free(infotxt);
|
|
free(prompts);
|
|
free(echo_on);
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
mm_answer_bsdauthrespond(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
char *response;
|
|
int r, authok;
|
|
|
|
if (!options.kbd_interactive_authentication)
|
|
fatal_f("kbd-int authentication not enabled");
|
|
if (authctxt->as == NULL)
|
|
fatal_f("no bsd auth session");
|
|
|
|
if ((r = sshbuf_get_cstring(m, &response, NULL)) != 0)
|
|
fatal_fr(r, "parse");
|
|
authok = options.kbd_interactive_authentication &&
|
|
auth_userresponse(authctxt->as, response, 0);
|
|
authctxt->as = NULL;
|
|
debug3_f("<%s> = <%d>", response, authok);
|
|
free(response);
|
|
|
|
sshbuf_reset(m);
|
|
if ((r = sshbuf_put_u32(m, authok)) != 0)
|
|
fatal_fr(r, "assemble");
|
|
|
|
debug3_f("sending authenticated: %d", authok);
|
|
mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
|
|
|
|
auth_method = "keyboard-interactive";
|
|
auth_submethod = "bsdauth";
|
|
|
|
return (authok != 0);
|
|
}
|
|
#endif
|
|
|
|
#ifdef USE_PAM
|
|
int
|
|
mm_answer_pam_start(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
if (!options.use_pam)
|
|
fatal("UsePAM not set, but ended up in %s anyway", __func__);
|
|
|
|
start_pam(ssh);
|
|
|
|
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1);
|
|
if (options.kbd_interactive_authentication)
|
|
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_INIT_CTX, 1);
|
|
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
mm_answer_pam_account(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
u_int ret;
|
|
int r;
|
|
|
|
if (!options.use_pam)
|
|
fatal("%s: PAM not enabled", __func__);
|
|
|
|
ret = do_pam_account();
|
|
|
|
if ((r = sshbuf_put_u32(m, ret)) != 0 ||
|
|
(r = sshbuf_put_stringb(m, loginmsg)) != 0)
|
|
fatal("%s: buffer error: %s", __func__, ssh_err(r));
|
|
|
|
mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m);
|
|
|
|
return (ret);
|
|
}
|
|
|
|
static void *sshpam_ctxt, *sshpam_authok;
|
|
extern KbdintDevice sshpam_device;
|
|
|
|
int
|
|
mm_answer_pam_init_ctx(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
u_int ok = 0;
|
|
int r;
|
|
|
|
debug3("%s", __func__);
|
|
if (!options.kbd_interactive_authentication)
|
|
fatal("%s: kbd-int authentication not enabled", __func__);
|
|
if (sshpam_ctxt != NULL)
|
|
fatal("%s: already called", __func__);
|
|
sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);
|
|
sshpam_authok = NULL;
|
|
sshbuf_reset(m);
|
|
if (sshpam_ctxt != NULL) {
|
|
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1);
|
|
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_QUERY, 1);
|
|
ok = 1;
|
|
}
|
|
if ((r = sshbuf_put_u32(m, ok)) != 0)
|
|
fatal("%s: buffer error: %s", __func__, ssh_err(r));
|
|
mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m);
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
mm_answer_pam_query(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
char *name = NULL, *info = NULL, **prompts = NULL;
|
|
u_int i, num = 0, *echo_on = 0;
|
|
int r, ret;
|
|
|
|
debug3("%s", __func__);
|
|
sshpam_authok = NULL;
|
|
if (sshpam_ctxt == NULL)
|
|
fatal("%s: no context", __func__);
|
|
ret = (sshpam_device.query)(sshpam_ctxt, &name, &info,
|
|
&num, &prompts, &echo_on);
|
|
if (ret == 0 && num == 0)
|
|
sshpam_authok = sshpam_ctxt;
|
|
if (num > 1 || name == NULL || info == NULL)
|
|
fatal("sshpam_device.query failed");
|
|
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_RESPOND, 1);
|
|
sshbuf_reset(m);
|
|
if ((r = sshbuf_put_u32(m, ret)) != 0 ||
|
|
(r = sshbuf_put_cstring(m, name)) != 0 ||
|
|
(r = sshbuf_put_cstring(m, info)) != 0 ||
|
|
(r = sshbuf_put_u32(m, sshpam_get_maxtries_reached())) != 0 ||
|
|
(r = sshbuf_put_u32(m, num)) != 0)
|
|
fatal("%s: buffer error: %s", __func__, ssh_err(r));
|
|
free(name);
|
|
free(info);
|
|
for (i = 0; i < num; ++i) {
|
|
if ((r = sshbuf_put_cstring(m, prompts[i])) != 0 ||
|
|
(r = sshbuf_put_u32(m, echo_on[i])) != 0)
|
|
fatal("%s: buffer error: %s", __func__, ssh_err(r));
|
|
free(prompts[i]);
|
|
}
|
|
free(prompts);
|
|
free(echo_on);
|
|
auth_method = "keyboard-interactive";
|
|
auth_submethod = "pam";
|
|
mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m);
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
mm_answer_pam_respond(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
char **resp;
|
|
u_int i, num;
|
|
int r, ret;
|
|
|
|
debug3("%s", __func__);
|
|
if (sshpam_ctxt == NULL)
|
|
fatal("%s: no context", __func__);
|
|
sshpam_authok = NULL;
|
|
if ((r = sshbuf_get_u32(m, &num)) != 0)
|
|
fatal("%s: buffer error: %s", __func__, ssh_err(r));
|
|
if (num > 0) {
|
|
resp = xcalloc(num, sizeof(char *));
|
|
for (i = 0; i < num; ++i) {
|
|
if ((r = sshbuf_get_cstring(m, &(resp[i]), NULL)) != 0)
|
|
fatal("%s: buffer error: %s",
|
|
__func__, ssh_err(r));
|
|
}
|
|
ret = (sshpam_device.respond)(sshpam_ctxt, num, resp);
|
|
for (i = 0; i < num; ++i)
|
|
free(resp[i]);
|
|
free(resp);
|
|
} else {
|
|
ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL);
|
|
}
|
|
sshbuf_reset(m);
|
|
if ((r = sshbuf_put_u32(m, ret)) != 0)
|
|
fatal("%s: buffer error: %s", __func__, ssh_err(r));
|
|
mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m);
|
|
auth_method = "keyboard-interactive";
|
|
auth_submethod = "pam";
|
|
if (ret == 0)
|
|
sshpam_authok = sshpam_ctxt;
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
mm_answer_pam_free_ctx(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
int r = sshpam_authok != NULL && sshpam_authok == sshpam_ctxt;
|
|
|
|
debug3("%s", __func__);
|
|
if (sshpam_ctxt == NULL)
|
|
fatal("%s: no context", __func__);
|
|
(sshpam_device.free_ctx)(sshpam_ctxt);
|
|
sshpam_ctxt = sshpam_authok = NULL;
|
|
sshbuf_reset(m);
|
|
mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m);
|
|
/* Allow another attempt */
|
|
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_INIT_CTX, 1);
|
|
auth_method = "keyboard-interactive";
|
|
auth_submethod = "pam";
|
|
return r;
|
|
}
|
|
#endif
|
|
|
|
int
|
|
mm_answer_keyallowed(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
struct sshkey *key = NULL;
|
|
char *cuser, *chost;
|
|
u_int pubkey_auth_attempt;
|
|
u_int type = 0;
|
|
int r, allowed = 0;
|
|
struct sshauthopt *opts = NULL;
|
|
|
|
debug3_f("entering");
|
|
if ((r = sshbuf_get_u32(m, &type)) != 0 ||
|
|
(r = sshbuf_get_cstring(m, &cuser, NULL)) != 0 ||
|
|
(r = sshbuf_get_cstring(m, &chost, NULL)) != 0 ||
|
|
(r = sshkey_froms(m, &key)) != 0 ||
|
|
(r = sshbuf_get_u32(m, &pubkey_auth_attempt)) != 0)
|
|
fatal_fr(r, "parse");
|
|
|
|
if (key != NULL && authctxt->valid) {
|
|
switch (type) {
|
|
case MM_USERKEY:
|
|
auth_method = "publickey";
|
|
if (!options.pubkey_authentication)
|
|
break;
|
|
if (auth2_key_already_used(authctxt, key))
|
|
break;
|
|
if (!key_base_type_match(auth_method, key,
|
|
options.pubkey_accepted_algos))
|
|
break;
|
|
allowed = user_key_allowed(ssh, authctxt->pw, key,
|
|
pubkey_auth_attempt, &opts);
|
|
break;
|
|
case MM_HOSTKEY:
|
|
auth_method = "hostbased";
|
|
if (!options.hostbased_authentication)
|
|
break;
|
|
if (auth2_key_already_used(authctxt, key))
|
|
break;
|
|
if (!key_base_type_match(auth_method, key,
|
|
options.hostbased_accepted_algos))
|
|
break;
|
|
allowed = hostbased_key_allowed(ssh, authctxt->pw,
|
|
cuser, chost, key);
|
|
auth2_record_info(authctxt,
|
|
"client user \"%.100s\", client host \"%.100s\"",
|
|
cuser, chost);
|
|
break;
|
|
default:
|
|
fatal_f("unknown key type %u", type);
|
|
break;
|
|
}
|
|
}
|
|
|
|
debug3_f("%s authentication%s: %s key is %s", auth_method,
|
|
pubkey_auth_attempt ? "" : " test",
|
|
(key == NULL || !authctxt->valid) ? "invalid" : sshkey_type(key),
|
|
allowed ? "allowed" : "not allowed");
|
|
|
|
auth2_record_key(authctxt, 0, key);
|
|
|
|
/* clear temporarily storage (used by verify) */
|
|
monitor_reset_key_state();
|
|
|
|
if (allowed) {
|
|
/* Save temporarily for comparison in verify */
|
|
if ((r = sshkey_to_blob(key, &key_blob, &key_bloblen)) != 0)
|
|
fatal_fr(r, "sshkey_to_blob");
|
|
key_blobtype = type;
|
|
key_opts = opts;
|
|
hostbased_cuser = cuser;
|
|
hostbased_chost = chost;
|
|
} else {
|
|
/* Log failed attempt */
|
|
auth_log(ssh, 0, 0, auth_method, NULL);
|
|
free(cuser);
|
|
free(chost);
|
|
}
|
|
sshkey_free(key);
|
|
|
|
sshbuf_reset(m);
|
|
if ((r = sshbuf_put_u32(m, allowed)) != 0)
|
|
fatal_fr(r, "assemble");
|
|
if (opts != NULL && (r = sshauthopt_serialise(opts, m, 1)) != 0)
|
|
fatal_fr(r, "sshauthopt_serialise");
|
|
mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
|
|
|
|
if (!allowed)
|
|
sshauthopt_free(opts);
|
|
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
monitor_valid_userblob(struct ssh *ssh, const u_char *data, u_int datalen)
|
|
{
|
|
struct sshbuf *b;
|
|
struct sshkey *hostkey = NULL;
|
|
const u_char *p;
|
|
char *userstyle, *cp;
|
|
size_t len;
|
|
u_char type;
|
|
int hostbound = 0, r, fail = 0;
|
|
|
|
if ((b = sshbuf_from(data, datalen)) == NULL)
|
|
fatal_f("sshbuf_from");
|
|
|
|
if (ssh->compat & SSH_OLD_SESSIONID) {
|
|
p = sshbuf_ptr(b);
|
|
len = sshbuf_len(b);
|
|
if ((session_id2 == NULL) ||
|
|
(len < session_id2_len) ||
|
|
(timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
|
|
fail++;
|
|
if ((r = sshbuf_consume(b, session_id2_len)) != 0)
|
|
fatal_fr(r, "consume");
|
|
} else {
|
|
if ((r = sshbuf_get_string_direct(b, &p, &len)) != 0)
|
|
fatal_fr(r, "parse sessionid");
|
|
if ((session_id2 == NULL) ||
|
|
(len != session_id2_len) ||
|
|
(timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
|
|
fail++;
|
|
}
|
|
if ((r = sshbuf_get_u8(b, &type)) != 0)
|
|
fatal_fr(r, "parse type");
|
|
if (type != SSH2_MSG_USERAUTH_REQUEST)
|
|
fail++;
|
|
if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
|
|
fatal_fr(r, "parse userstyle");
|
|
xasprintf(&userstyle, "%s%s%s", authctxt->user,
|
|
authctxt->style ? ":" : "",
|
|
authctxt->style ? authctxt->style : "");
|
|
if (strcmp(userstyle, cp) != 0) {
|
|
logit("wrong user name passed to monitor: "
|
|
"expected %s != %.100s", userstyle, cp);
|
|
fail++;
|
|
}
|
|
free(userstyle);
|
|
free(cp);
|
|
if ((r = sshbuf_skip_string(b)) != 0 || /* service */
|
|
(r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
|
|
fatal_fr(r, "parse method");
|
|
if (strcmp("publickey", cp) != 0) {
|
|
if (strcmp("publickey-hostbound-v00@openssh.com", cp) == 0)
|
|
hostbound = 1;
|
|
else
|
|
fail++;
|
|
}
|
|
free(cp);
|
|
if ((r = sshbuf_get_u8(b, &type)) != 0)
|
|
fatal_fr(r, "parse pktype");
|
|
if (type == 0)
|
|
fail++;
|
|
if ((r = sshbuf_skip_string(b)) != 0 || /* pkalg */
|
|
(r = sshbuf_skip_string(b)) != 0 || /* pkblob */
|
|
(hostbound && (r = sshkey_froms(b, &hostkey)) != 0))
|
|
fatal_fr(r, "parse pk");
|
|
if (sshbuf_len(b) != 0)
|
|
fail++;
|
|
sshbuf_free(b);
|
|
if (hostkey != NULL) {
|
|
/*
|
|
* Ensure this is actually one of our hostkeys; unfortunately
|
|
* can't check ssh->kex->initial_hostkey directly at this point
|
|
* as packet state has not yet been exported to monitor.
|
|
*/
|
|
if (get_hostkey_index(hostkey, 1, ssh) == -1)
|
|
fatal_f("hostbound hostkey does not match");
|
|
sshkey_free(hostkey);
|
|
}
|
|
return (fail == 0);
|
|
}
|
|
|
|
static int
|
|
monitor_valid_hostbasedblob(const u_char *data, u_int datalen,
|
|
const char *cuser, const char *chost)
|
|
{
|
|
struct sshbuf *b;
|
|
const u_char *p;
|
|
char *cp, *userstyle;
|
|
size_t len;
|
|
int r, fail = 0;
|
|
u_char type;
|
|
|
|
if ((b = sshbuf_from(data, datalen)) == NULL)
|
|
fatal_f("sshbuf_new");
|
|
if ((r = sshbuf_get_string_direct(b, &p, &len)) != 0)
|
|
fatal_fr(r, "parse sessionid");
|
|
|
|
if ((session_id2 == NULL) ||
|
|
(len != session_id2_len) ||
|
|
(timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
|
|
fail++;
|
|
|
|
if ((r = sshbuf_get_u8(b, &type)) != 0)
|
|
fatal_fr(r, "parse type");
|
|
if (type != SSH2_MSG_USERAUTH_REQUEST)
|
|
fail++;
|
|
if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
|
|
fatal_fr(r, "parse userstyle");
|
|
xasprintf(&userstyle, "%s%s%s", authctxt->user,
|
|
authctxt->style ? ":" : "",
|
|
authctxt->style ? authctxt->style : "");
|
|
if (strcmp(userstyle, cp) != 0) {
|
|
logit("wrong user name passed to monitor: "
|
|
"expected %s != %.100s", userstyle, cp);
|
|
fail++;
|
|
}
|
|
free(userstyle);
|
|
free(cp);
|
|
if ((r = sshbuf_skip_string(b)) != 0 || /* service */
|
|
(r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
|
|
fatal_fr(r, "parse method");
|
|
if (strcmp(cp, "hostbased") != 0)
|
|
fail++;
|
|
free(cp);
|
|
if ((r = sshbuf_skip_string(b)) != 0 || /* pkalg */
|
|
(r = sshbuf_skip_string(b)) != 0) /* pkblob */
|
|
fatal_fr(r, "parse pk");
|
|
|
|
/* verify client host, strip trailing dot if necessary */
|
|
if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
|
|
fatal_fr(r, "parse host");
|
|
if (((len = strlen(cp)) > 0) && cp[len - 1] == '.')
|
|
cp[len - 1] = '\0';
|
|
if (strcmp(cp, chost) != 0)
|
|
fail++;
|
|
free(cp);
|
|
|
|
/* verify client user */
|
|
if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
|
|
fatal_fr(r, "parse ruser");
|
|
if (strcmp(cp, cuser) != 0)
|
|
fail++;
|
|
free(cp);
|
|
|
|
if (sshbuf_len(b) != 0)
|
|
fail++;
|
|
sshbuf_free(b);
|
|
return (fail == 0);
|
|
}
|
|
|
|
int
|
|
mm_answer_keyverify(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
struct sshkey *key;
|
|
const u_char *signature, *data, *blob;
|
|
char *sigalg = NULL, *fp = NULL;
|
|
size_t signaturelen, datalen, bloblen;
|
|
int r, ret, req_presence = 0, req_verify = 0, valid_data = 0;
|
|
int encoded_ret;
|
|
struct sshkey_sig_details *sig_details = NULL;
|
|
|
|
if ((r = sshbuf_get_string_direct(m, &blob, &bloblen)) != 0 ||
|
|
(r = sshbuf_get_string_direct(m, &signature, &signaturelen)) != 0 ||
|
|
(r = sshbuf_get_string_direct(m, &data, &datalen)) != 0 ||
|
|
(r = sshbuf_get_cstring(m, &sigalg, NULL)) != 0)
|
|
fatal_fr(r, "parse");
|
|
|
|
if (hostbased_cuser == NULL || hostbased_chost == NULL ||
|
|
!monitor_allowed_key(blob, bloblen))
|
|
fatal_f("bad key, not previously allowed");
|
|
|
|
/* Empty signature algorithm means NULL. */
|
|
if (*sigalg == '\0') {
|
|
free(sigalg);
|
|
sigalg = NULL;
|
|
}
|
|
|
|
/* XXX use sshkey_froms here; need to change key_blob, etc. */
|
|
if ((r = sshkey_from_blob(blob, bloblen, &key)) != 0)
|
|
fatal_fr(r, "parse key");
|
|
|
|
switch (key_blobtype) {
|
|
case MM_USERKEY:
|
|
valid_data = monitor_valid_userblob(ssh, data, datalen);
|
|
auth_method = "publickey";
|
|
break;
|
|
case MM_HOSTKEY:
|
|
valid_data = monitor_valid_hostbasedblob(data, datalen,
|
|
hostbased_cuser, hostbased_chost);
|
|
auth_method = "hostbased";
|
|
break;
|
|
default:
|
|
valid_data = 0;
|
|
break;
|
|
}
|
|
if (!valid_data)
|
|
fatal_f("bad %s signature data blob",
|
|
key_blobtype == MM_USERKEY ? "userkey" :
|
|
(key_blobtype == MM_HOSTKEY ? "hostkey" : "unknown"));
|
|
|
|
if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
|
|
SSH_FP_DEFAULT)) == NULL)
|
|
fatal_f("sshkey_fingerprint failed");
|
|
|
|
ret = sshkey_verify(key, signature, signaturelen, data, datalen,
|
|
sigalg, ssh->compat, &sig_details);
|
|
debug3_f("%s %s signature using %s %s%s%s", auth_method,
|
|
sshkey_type(key), sigalg == NULL ? "default" : sigalg,
|
|
(ret == 0) ? "verified" : "unverified",
|
|
(ret != 0) ? ": " : "", (ret != 0) ? ssh_err(ret) : "");
|
|
|
|
if (ret == 0 && key_blobtype == MM_USERKEY && sig_details != NULL) {
|
|
req_presence = (options.pubkey_auth_options &
|
|
PUBKEYAUTH_TOUCH_REQUIRED) ||
|
|
!key_opts->no_require_user_presence;
|
|
if (req_presence &&
|
|
(sig_details->sk_flags & SSH_SK_USER_PRESENCE_REQD) == 0) {
|
|
error("public key %s %s signature for %s%s from %.128s "
|
|
"port %d rejected: user presence "
|
|
"(authenticator touch) requirement not met ",
|
|
sshkey_type(key), fp,
|
|
authctxt->valid ? "" : "invalid user ",
|
|
authctxt->user, ssh_remote_ipaddr(ssh),
|
|
ssh_remote_port(ssh));
|
|
ret = SSH_ERR_SIGNATURE_INVALID;
|
|
}
|
|
req_verify = (options.pubkey_auth_options &
|
|
PUBKEYAUTH_VERIFY_REQUIRED) || key_opts->require_verify;
|
|
if (req_verify &&
|
|
(sig_details->sk_flags & SSH_SK_USER_VERIFICATION_REQD) == 0) {
|
|
error("public key %s %s signature for %s%s from %.128s "
|
|
"port %d rejected: user verification requirement "
|
|
"not met ", sshkey_type(key), fp,
|
|
authctxt->valid ? "" : "invalid user ",
|
|
authctxt->user, ssh_remote_ipaddr(ssh),
|
|
ssh_remote_port(ssh));
|
|
ret = SSH_ERR_SIGNATURE_INVALID;
|
|
}
|
|
}
|
|
auth2_record_key(authctxt, ret == 0, key);
|
|
|
|
if (key_blobtype == MM_USERKEY)
|
|
auth_activate_options(ssh, key_opts);
|
|
monitor_reset_key_state();
|
|
|
|
sshbuf_reset(m);
|
|
|
|
/* encode ret != 0 as positive integer, since we're sending u32 */
|
|
encoded_ret = (ret != 0);
|
|
if ((r = sshbuf_put_u32(m, encoded_ret)) != 0 ||
|
|
(r = sshbuf_put_u8(m, sig_details != NULL)) != 0)
|
|
fatal_fr(r, "assemble");
|
|
if (sig_details != NULL) {
|
|
if ((r = sshbuf_put_u32(m, sig_details->sk_counter)) != 0 ||
|
|
(r = sshbuf_put_u8(m, sig_details->sk_flags)) != 0)
|
|
fatal_fr(r, "assemble sk");
|
|
}
|
|
sshkey_sig_details_free(sig_details);
|
|
mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
|
|
|
|
free(sigalg);
|
|
free(fp);
|
|
sshkey_free(key);
|
|
|
|
return ret == 0;
|
|
}
|
|
|
|
static void
|
|
mm_record_login(struct ssh *ssh, Session *s, struct passwd *pw)
|
|
{
|
|
socklen_t fromlen;
|
|
struct sockaddr_storage from;
|
|
|
|
/*
|
|
* Get IP address of client. If the connection is not a socket, let
|
|
* the address be 0.0.0.0.
|
|
*/
|
|
memset(&from, 0, sizeof(from));
|
|
fromlen = sizeof(from);
|
|
if (ssh_packet_connection_is_on_socket(ssh)) {
|
|
if (getpeername(ssh_packet_get_connection_in(ssh),
|
|
(struct sockaddr *)&from, &fromlen) == -1) {
|
|
debug("getpeername: %.100s", strerror(errno));
|
|
cleanup_exit(255);
|
|
}
|
|
}
|
|
/* Record that there was a login on that tty from the remote host. */
|
|
record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
|
|
session_get_remote_name_or_ip(ssh, utmp_len, options.use_dns),
|
|
(struct sockaddr *)&from, fromlen);
|
|
}
|
|
|
|
static void
|
|
mm_session_close(Session *s)
|
|
{
|
|
debug3_f("session %d pid %ld", s->self, (long)s->pid);
|
|
if (s->ttyfd != -1) {
|
|
debug3_f("tty %s ptyfd %d", s->tty, s->ptyfd);
|
|
session_pty_cleanup2(s);
|
|
}
|
|
session_unused(s->self);
|
|
}
|
|
|
|
int
|
|
mm_answer_pty(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
extern struct monitor *pmonitor;
|
|
Session *s;
|
|
int r, res, fd0;
|
|
|
|
debug3_f("entering");
|
|
|
|
sshbuf_reset(m);
|
|
s = session_new();
|
|
if (s == NULL)
|
|
goto error;
|
|
s->authctxt = authctxt;
|
|
s->pw = authctxt->pw;
|
|
s->pid = pmonitor->m_pid;
|
|
res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
|
|
if (res == 0)
|
|
goto error;
|
|
pty_setowner(authctxt->pw, s->tty);
|
|
|
|
if ((r = sshbuf_put_u32(m, 1)) != 0 ||
|
|
(r = sshbuf_put_cstring(m, s->tty)) != 0)
|
|
fatal_fr(r, "assemble");
|
|
|
|
/* We need to trick ttyslot */
|
|
if (dup2(s->ttyfd, 0) == -1)
|
|
fatal_f("dup2");
|
|
|
|
mm_record_login(ssh, s, authctxt->pw);
|
|
|
|
/* Now we can close the file descriptor again */
|
|
close(0);
|
|
|
|
/* send messages generated by record_login */
|
|
if ((r = sshbuf_put_stringb(m, loginmsg)) != 0)
|
|
fatal_fr(r, "assemble loginmsg");
|
|
sshbuf_reset(loginmsg);
|
|
|
|
mm_request_send(sock, MONITOR_ANS_PTY, m);
|
|
|
|
if (mm_send_fd(sock, s->ptyfd) == -1 ||
|
|
mm_send_fd(sock, s->ttyfd) == -1)
|
|
fatal_f("send fds failed");
|
|
|
|
/* make sure nothing uses fd 0 */
|
|
if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) == -1)
|
|
fatal_f("open(/dev/null): %s", strerror(errno));
|
|
if (fd0 != 0)
|
|
error_f("fd0 %d != 0", fd0);
|
|
|
|
/* slave side of pty is not needed */
|
|
close(s->ttyfd);
|
|
s->ttyfd = s->ptyfd;
|
|
/* no need to dup() because nobody closes ptyfd */
|
|
s->ptymaster = s->ptyfd;
|
|
|
|
debug3_f("tty %s ptyfd %d", s->tty, s->ttyfd);
|
|
|
|
return (0);
|
|
|
|
error:
|
|
if (s != NULL)
|
|
mm_session_close(s);
|
|
if ((r = sshbuf_put_u32(m, 0)) != 0)
|
|
fatal_fr(r, "assemble 0");
|
|
mm_request_send(sock, MONITOR_ANS_PTY, m);
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
mm_answer_pty_cleanup(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
Session *s;
|
|
char *tty;
|
|
int r;
|
|
|
|
debug3_f("entering");
|
|
|
|
if ((r = sshbuf_get_cstring(m, &tty, NULL)) != 0)
|
|
fatal_fr(r, "parse tty");
|
|
if ((s = session_by_tty(tty)) != NULL)
|
|
mm_session_close(s);
|
|
sshbuf_reset(m);
|
|
free(tty);
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
mm_answer_term(struct ssh *ssh, int sock, struct sshbuf *req)
|
|
{
|
|
extern struct monitor *pmonitor;
|
|
int res, status;
|
|
|
|
debug3_f("tearing down sessions");
|
|
|
|
/* The child is terminating */
|
|
session_destroy_all(ssh, &mm_session_close);
|
|
|
|
#ifdef USE_PAM
|
|
if (options.use_pam)
|
|
sshpam_cleanup();
|
|
#endif
|
|
|
|
while (waitpid(pmonitor->m_pid, &status, 0) == -1)
|
|
if (errno != EINTR)
|
|
exit(1);
|
|
|
|
res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
|
|
|
|
/* Terminate process */
|
|
exit(res);
|
|
}
|
|
|
|
#ifdef SSH_AUDIT_EVENTS
|
|
/* Report that an audit event occurred */
|
|
int
|
|
mm_answer_audit_event(struct ssh *ssh, int socket, struct sshbuf *m)
|
|
{
|
|
u_int n;
|
|
ssh_audit_event_t event;
|
|
int r;
|
|
|
|
debug3("%s entering", __func__);
|
|
|
|
if ((r = sshbuf_get_u32(m, &n)) != 0)
|
|
fatal("%s: buffer error: %s", __func__, ssh_err(r));
|
|
event = (ssh_audit_event_t)n;
|
|
switch (event) {
|
|
case SSH_AUTH_FAIL_PUBKEY:
|
|
case SSH_AUTH_FAIL_HOSTBASED:
|
|
case SSH_AUTH_FAIL_GSSAPI:
|
|
case SSH_LOGIN_EXCEED_MAXTRIES:
|
|
case SSH_LOGIN_ROOT_DENIED:
|
|
case SSH_CONNECTION_CLOSE:
|
|
case SSH_INVALID_USER:
|
|
audit_event(ssh, event);
|
|
break;
|
|
default:
|
|
fatal("Audit event type %d not permitted", event);
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
mm_answer_audit_command(struct ssh *ssh, int socket, struct sshbuf *m)
|
|
{
|
|
char *cmd;
|
|
int r;
|
|
|
|
debug3("%s entering", __func__);
|
|
if ((r = sshbuf_get_cstring(m, &cmd, NULL)) != 0)
|
|
fatal("%s: buffer error: %s", __func__, ssh_err(r));
|
|
/* sanity check command, if so how? */
|
|
audit_run_command(cmd);
|
|
free(cmd);
|
|
return (0);
|
|
}
|
|
#endif /* SSH_AUDIT_EVENTS */
|
|
|
|
void
|
|
monitor_clear_keystate(struct ssh *ssh, struct monitor *pmonitor)
|
|
{
|
|
ssh_clear_newkeys(ssh, MODE_IN);
|
|
ssh_clear_newkeys(ssh, MODE_OUT);
|
|
sshbuf_free(child_state);
|
|
child_state = NULL;
|
|
}
|
|
|
|
void
|
|
monitor_apply_keystate(struct ssh *ssh, struct monitor *pmonitor)
|
|
{
|
|
struct kex *kex;
|
|
int r;
|
|
|
|
debug3_f("packet_set_state");
|
|
if ((r = ssh_packet_set_state(ssh, child_state)) != 0)
|
|
fatal_fr(r, "packet_set_state");
|
|
sshbuf_free(child_state);
|
|
child_state = NULL;
|
|
if ((kex = ssh->kex) == NULL)
|
|
fatal_f("internal error: ssh->kex == NULL");
|
|
if (session_id2_len != sshbuf_len(ssh->kex->session_id)) {
|
|
fatal_f("incorrect session id length %zu (expected %u)",
|
|
sshbuf_len(ssh->kex->session_id), session_id2_len);
|
|
}
|
|
if (memcmp(sshbuf_ptr(ssh->kex->session_id), session_id2,
|
|
session_id2_len) != 0)
|
|
fatal_f("session ID mismatch");
|
|
/* XXX set callbacks */
|
|
#ifdef WITH_OPENSSL
|
|
kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_server;
|
|
kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_server;
|
|
kex->kex[KEX_DH_GRP14_SHA256] = kex_gen_server;
|
|
kex->kex[KEX_DH_GRP16_SHA512] = kex_gen_server;
|
|
kex->kex[KEX_DH_GRP18_SHA512] = kex_gen_server;
|
|
kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
|
|
kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
|
|
# ifdef OPENSSL_HAS_ECC
|
|
kex->kex[KEX_ECDH_SHA2] = kex_gen_server;
|
|
# endif
|
|
#endif /* WITH_OPENSSL */
|
|
kex->kex[KEX_C25519_SHA256] = kex_gen_server;
|
|
kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_server;
|
|
kex->load_host_public_key=&get_hostkey_public_by_type;
|
|
kex->load_host_private_key=&get_hostkey_private_by_type;
|
|
kex->host_key_index=&get_hostkey_index;
|
|
kex->sign = sshd_hostkey_sign;
|
|
}
|
|
|
|
/* This function requires careful sanity checking */
|
|
|
|
void
|
|
mm_get_keystate(struct ssh *ssh, struct monitor *pmonitor)
|
|
{
|
|
debug3_f("Waiting for new keys");
|
|
|
|
if ((child_state = sshbuf_new()) == NULL)
|
|
fatal_f("sshbuf_new failed");
|
|
mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT,
|
|
child_state);
|
|
debug3_f("GOT new keys");
|
|
}
|
|
|
|
|
|
/* XXX */
|
|
|
|
#define FD_CLOSEONEXEC(x) do { \
|
|
if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \
|
|
fatal("fcntl(%d, F_SETFD)", x); \
|
|
} while (0)
|
|
|
|
static void
|
|
monitor_openfds(struct monitor *mon, int do_logfds)
|
|
{
|
|
int pair[2];
|
|
#ifdef SO_ZEROIZE
|
|
int on = 1;
|
|
#endif
|
|
|
|
if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
|
|
fatal_f("socketpair: %s", strerror(errno));
|
|
#ifdef SO_ZEROIZE
|
|
if (setsockopt(pair[0], SOL_SOCKET, SO_ZEROIZE, &on, sizeof(on)) == -1)
|
|
error("setsockopt SO_ZEROIZE(0): %.100s", strerror(errno));
|
|
if (setsockopt(pair[1], SOL_SOCKET, SO_ZEROIZE, &on, sizeof(on)) == -1)
|
|
error("setsockopt SO_ZEROIZE(1): %.100s", strerror(errno));
|
|
#endif
|
|
FD_CLOSEONEXEC(pair[0]);
|
|
FD_CLOSEONEXEC(pair[1]);
|
|
mon->m_recvfd = pair[0];
|
|
mon->m_sendfd = pair[1];
|
|
|
|
if (do_logfds) {
|
|
if (pipe(pair) == -1)
|
|
fatal_f("pipe: %s", strerror(errno));
|
|
FD_CLOSEONEXEC(pair[0]);
|
|
FD_CLOSEONEXEC(pair[1]);
|
|
mon->m_log_recvfd = pair[0];
|
|
mon->m_log_sendfd = pair[1];
|
|
} else
|
|
mon->m_log_recvfd = mon->m_log_sendfd = -1;
|
|
}
|
|
|
|
#define MM_MEMSIZE 65536
|
|
|
|
struct monitor *
|
|
monitor_init(void)
|
|
{
|
|
struct monitor *mon;
|
|
|
|
mon = xcalloc(1, sizeof(*mon));
|
|
monitor_openfds(mon, 1);
|
|
|
|
return mon;
|
|
}
|
|
|
|
void
|
|
monitor_reinit(struct monitor *mon)
|
|
{
|
|
monitor_openfds(mon, 0);
|
|
}
|
|
|
|
#ifdef GSSAPI
|
|
int
|
|
mm_answer_gss_setup_ctx(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
gss_OID_desc goid;
|
|
OM_uint32 major;
|
|
size_t len;
|
|
u_char *p;
|
|
int r;
|
|
|
|
if (!options.gss_authentication)
|
|
fatal_f("GSSAPI authentication not enabled");
|
|
|
|
if ((r = sshbuf_get_string(m, &p, &len)) != 0)
|
|
fatal_fr(r, "parse");
|
|
goid.elements = p;
|
|
goid.length = len;
|
|
|
|
major = ssh_gssapi_server_ctx(&gsscontext, &goid);
|
|
|
|
free(goid.elements);
|
|
|
|
sshbuf_reset(m);
|
|
if ((r = sshbuf_put_u32(m, major)) != 0)
|
|
fatal_fr(r, "assemble");
|
|
|
|
mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
|
|
|
|
/* Now we have a context, enable the step */
|
|
monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
|
|
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
mm_answer_gss_accept_ctx(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
gss_buffer_desc in;
|
|
gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
|
|
OM_uint32 major, minor;
|
|
OM_uint32 flags = 0; /* GSI needs this */
|
|
int r;
|
|
|
|
if (!options.gss_authentication)
|
|
fatal_f("GSSAPI authentication not enabled");
|
|
|
|
if ((r = ssh_gssapi_get_buffer_desc(m, &in)) != 0)
|
|
fatal_fr(r, "ssh_gssapi_get_buffer_desc");
|
|
major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
|
|
free(in.value);
|
|
|
|
sshbuf_reset(m);
|
|
if ((r = sshbuf_put_u32(m, major)) != 0 ||
|
|
(r = sshbuf_put_string(m, out.value, out.length)) != 0 ||
|
|
(r = sshbuf_put_u32(m, flags)) != 0)
|
|
fatal_fr(r, "assemble");
|
|
mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
|
|
|
|
gss_release_buffer(&minor, &out);
|
|
|
|
if (major == GSS_S_COMPLETE) {
|
|
monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
|
|
monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
|
|
monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
mm_answer_gss_checkmic(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
gss_buffer_desc gssbuf, mic;
|
|
OM_uint32 ret;
|
|
int r;
|
|
|
|
if (!options.gss_authentication)
|
|
fatal_f("GSSAPI authentication not enabled");
|
|
|
|
if ((r = ssh_gssapi_get_buffer_desc(m, &gssbuf)) != 0 ||
|
|
(r = ssh_gssapi_get_buffer_desc(m, &mic)) != 0)
|
|
fatal_fr(r, "ssh_gssapi_get_buffer_desc");
|
|
|
|
ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
|
|
|
|
free(gssbuf.value);
|
|
free(mic.value);
|
|
|
|
sshbuf_reset(m);
|
|
if ((r = sshbuf_put_u32(m, ret)) != 0)
|
|
fatal_fr(r, "assemble");
|
|
|
|
mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
|
|
|
|
if (!GSS_ERROR(ret))
|
|
monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
|
|
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
mm_answer_gss_userok(struct ssh *ssh, int sock, struct sshbuf *m)
|
|
{
|
|
int r, authenticated;
|
|
const char *displayname;
|
|
|
|
if (!options.gss_authentication)
|
|
fatal_f("GSSAPI authentication not enabled");
|
|
|
|
authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
|
|
|
|
sshbuf_reset(m);
|
|
if ((r = sshbuf_put_u32(m, authenticated)) != 0)
|
|
fatal_fr(r, "assemble");
|
|
|
|
debug3_f("sending result %d", authenticated);
|
|
mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
|
|
|
|
auth_method = "gssapi-with-mic";
|
|
|
|
if ((displayname = ssh_gssapi_displayname()) != NULL)
|
|
auth2_record_info(authctxt, "%s", displayname);
|
|
|
|
/* Monitor loop will terminate if authenticated */
|
|
return (authenticated);
|
|
}
|
|
#endif /* GSSAPI */
|
|
|