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upstream: split the low-level file handling functions out from
auth2-pubkey.c Put them in a new auth2-pubkeyfile.c to make it easier to refer to them (e.g. in unit/fuzz tests) without having to refer to everything else pubkey auth brings in. ok dtucker@ OpenBSD-Commit-ID: 3fdca2c61ad97dc1b8d4a7346816f83dc4ce2217
This commit is contained in:
djm@openbsd.org
Damien Miller
parent
3b0b142d2a
commit
c83d8c4d6f
@ -123,7 +123,7 @@ SSHDOBJS=sshd.o auth-rhosts.o auth-passwd.o \
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auth.o auth2.o auth-options.o session.o \
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auth2-chall.o groupaccess.o \
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auth-bsdauth.o auth2-hostbased.o auth2-kbdint.o \
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auth2-none.o auth2-passwd.o auth2-pubkey.o \
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auth2-none.o auth2-passwd.o auth2-pubkey.o auth2-pubkeyfile.o \
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monitor.o monitor_wrap.o auth-krb5.o \
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auth2-gss.o gss-serv.o gss-serv-krb5.o \
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loginrec.o auth-pam.o auth-shadow.o auth-sia.o \
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94
auth.c
94
auth.c
@ -1,4 +1,4 @@
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/* $OpenBSD: auth.c,v 1.156 2022/05/27 05:01:25 djm Exp $ */
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/* $OpenBSD: auth.c,v 1.157 2022/05/27 05:02:46 djm Exp $ */
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/*
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* Copyright (c) 2000 Markus Friedl. All rights reserved.
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*
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@ -912,95 +912,3 @@ auth_restrict_session(struct ssh *ssh)
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fatal_f("failed to restrict session");
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sshauthopt_free(restricted);
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}
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int
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auth_authorise_keyopts(struct passwd *pw, struct sshauthopt *opts,
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int allow_cert_authority, const char *remote_ip, const char *remote_host,
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const char *loc)
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{
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time_t now = time(NULL);
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char buf[64];
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/*
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* Check keys/principals file expiry time.
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* NB. validity interval in certificate is handled elsewhere.
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*/
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if (opts->valid_before && now > 0 &&
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opts->valid_before < (uint64_t)now) {
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format_absolute_time(opts->valid_before, buf, sizeof(buf));
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debug("%s: entry expired at %s", loc, buf);
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auth_debug_add("%s: entry expired at %s", loc, buf);
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return -1;
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}
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/* Consistency checks */
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if (opts->cert_principals != NULL && !opts->cert_authority) {
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debug("%s: principals on non-CA key", loc);
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auth_debug_add("%s: principals on non-CA key", loc);
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/* deny access */
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return -1;
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}
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/* cert-authority flag isn't valid in authorized_principals files */
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if (!allow_cert_authority && opts->cert_authority) {
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debug("%s: cert-authority flag invalid here", loc);
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auth_debug_add("%s: cert-authority flag invalid here", loc);
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/* deny access */
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return -1;
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}
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/* Perform from= checks */
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if (opts->required_from_host_keys != NULL) {
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switch (match_host_and_ip(remote_host, remote_ip,
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opts->required_from_host_keys )) {
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case 1:
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/* Host name matches. */
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break;
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case -1:
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default:
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debug("%s: invalid from criteria", loc);
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auth_debug_add("%s: invalid from criteria", loc);
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/* FALLTHROUGH */
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case 0:
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logit("%s: Authentication tried for %.100s with "
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"correct key but not from a permitted "
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"host (host=%.200s, ip=%.200s, required=%.200s).",
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loc, pw->pw_name, remote_host, remote_ip,
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opts->required_from_host_keys);
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auth_debug_add("%s: Your host '%.200s' is not "
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"permitted to use this key for login.",
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loc, remote_host);
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/* deny access */
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return -1;
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}
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}
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/* Check source-address restriction from certificate */
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if (opts->required_from_host_cert != NULL) {
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switch (addr_match_cidr_list(remote_ip,
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opts->required_from_host_cert)) {
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case 1:
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/* accepted */
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break;
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case -1:
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default:
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/* invalid */
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error("%s: Certificate source-address invalid", loc);
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/* FALLTHROUGH */
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case 0:
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logit("%s: Authentication tried for %.100s with valid "
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"certificate but not from a permitted source "
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"address (%.200s).", loc, pw->pw_name, remote_ip);
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auth_debug_add("%s: Your address '%.200s' is not "
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"permitted to use this certificate for login.",
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loc, remote_ip);
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return -1;
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}
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}
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/*
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*
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* XXX this is spammy. We should report remotely only for keys
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* that are successful in actual auth attempts, and not PK_OK
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* tests.
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*/
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auth_log_authopts(loc, opts, 1);
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return 0;
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}
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18
auth.h
18
auth.h
@ -1,4 +1,4 @@
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/* $OpenBSD: auth.h,v 1.103 2022/05/27 05:01:25 djm Exp $ */
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/* $OpenBSD: auth.h,v 1.104 2022/05/27 05:02:46 djm Exp $ */
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/*
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* Copyright (c) 2000 Markus Friedl. All rights reserved.
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@ -29,6 +29,7 @@
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#define AUTH_H
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#include <signal.h>
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#include <stdio.h>
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#ifdef HAVE_LOGIN_CAP
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#include <login_cap.h>
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@ -44,6 +45,7 @@ struct passwd;
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struct ssh;
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struct sshbuf;
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struct sshkey;
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struct sshkey_cert;
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struct sshauthopt;
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typedef struct Authctxt Authctxt;
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@ -214,8 +216,6 @@ int sshd_hostkey_sign(struct ssh *, struct sshkey *, struct sshkey *,
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const struct sshauthopt *auth_options(struct ssh *);
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int auth_activate_options(struct ssh *, struct sshauthopt *);
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void auth_restrict_session(struct ssh *);
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int auth_authorise_keyopts(struct passwd *pw, struct sshauthopt *, int,
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const char *, const char *, const char *);
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void auth_log_authopts(const char *, const struct sshauthopt *, int);
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/* debug messages during authentication */
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@ -226,6 +226,18 @@ void auth_debug_reset(void);
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struct passwd *fakepw(void);
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/* auth2-pubkeyfile.c */
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int auth_authorise_keyopts(struct passwd *, struct sshauthopt *, int,
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const char *, const char *, const char *);
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int auth_check_principals_line(char *, const struct sshkey_cert *,
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const char *, struct sshauthopt **);
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int auth_process_principals(FILE *, const char *,
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const struct sshkey_cert *, struct sshauthopt **);
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int auth_check_authkey_line(struct passwd *, struct sshkey *,
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char *, const char *, const char *, const char *, struct sshauthopt **);
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int auth_check_authkeys_file(struct passwd *, FILE *, char *,
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struct sshkey *, const char *, const char *, struct sshauthopt **);
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int sys_auth_passwd(struct ssh *, const char *);
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#if defined(KRB5) && !defined(HEIMDAL)
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311
auth2-pubkey.c
311
auth2-pubkey.c
@ -1,6 +1,7 @@
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/* $OpenBSD: auth2-pubkey.c,v 1.114 2022/05/27 05:01:25 djm Exp $ */
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/* $OpenBSD: auth2-pubkey.c,v 1.115 2022/05/27 05:02:46 djm Exp $ */
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/*
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* Copyright (c) 2000 Markus Friedl. All rights reserved.
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* Copyright (c) 2010 Damien Miller. 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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@ -26,11 +27,9 @@
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#include "includes.h"
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <stdlib.h>
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#include <errno.h>
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#include <fcntl.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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@ -67,7 +66,6 @@
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#include "authfile.h"
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#include "match.h"
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#include "ssherr.h"
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#include "kex.h"
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#include "channels.h" /* XXX for session.h */
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#include "session.h" /* XXX for child_set_env(); refactor? */
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#include "sk-api.h"
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@ -321,120 +319,6 @@ done:
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return authenticated;
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}
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static int
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match_principals_option(const char *principal_list, struct sshkey_cert *cert)
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{
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char *result;
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u_int i;
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/* XXX percent_expand() sequences for authorized_principals? */
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for (i = 0; i < cert->nprincipals; i++) {
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if ((result = match_list(cert->principals[i],
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principal_list, NULL)) != NULL) {
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debug3("matched principal from key options \"%.100s\"",
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result);
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free(result);
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return 1;
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}
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}
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return 0;
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}
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/*
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* Process a single authorized_principals format line. Returns 0 and sets
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* authoptsp is principal is authorised, -1 otherwise. "loc" is used as a
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* log preamble for file/line information.
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*/
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static int
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check_principals_line(char *cp, const struct sshkey_cert *cert,
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const char *loc, struct sshauthopt **authoptsp)
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{
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u_int i, found = 0;
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char *ep, *line_opts;
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const char *reason = NULL;
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struct sshauthopt *opts = NULL;
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if (authoptsp != NULL)
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*authoptsp = NULL;
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/* Trim trailing whitespace. */
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ep = cp + strlen(cp) - 1;
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while (ep > cp && (*ep == '\n' || *ep == ' ' || *ep == '\t'))
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*ep-- = '\0';
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/*
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* If the line has internal whitespace then assume it has
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* key options.
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*/
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line_opts = NULL;
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if ((ep = strrchr(cp, ' ')) != NULL ||
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(ep = strrchr(cp, '\t')) != NULL) {
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for (; *ep == ' ' || *ep == '\t'; ep++)
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;
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line_opts = cp;
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cp = ep;
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}
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if ((opts = sshauthopt_parse(line_opts, &reason)) == NULL) {
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debug("%s: bad principals options: %s", loc, reason);
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auth_debug_add("%s: bad principals options: %s", loc, reason);
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return -1;
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}
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/* Check principals in cert against those on line */
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for (i = 0; i < cert->nprincipals; i++) {
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if (strcmp(cp, cert->principals[i]) != 0)
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continue;
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debug3("%s: matched principal \"%.100s\"",
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loc, cert->principals[i]);
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found = 1;
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}
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if (found && authoptsp != NULL) {
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*authoptsp = opts;
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opts = NULL;
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}
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sshauthopt_free(opts);
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return found ? 0 : -1;
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}
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static int
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process_principals(FILE *f, const char *file,
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const struct sshkey_cert *cert, struct sshauthopt **authoptsp)
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{
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char loc[256], *line = NULL, *cp, *ep;
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size_t linesize = 0;
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u_long linenum = 0, nonblank = 0;
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u_int found_principal = 0;
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if (authoptsp != NULL)
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*authoptsp = NULL;
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while (getline(&line, &linesize, f) != -1) {
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linenum++;
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/* Always consume entire input */
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if (found_principal)
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continue;
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/* Skip leading whitespace. */
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for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
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;
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/* Skip blank and comment lines. */
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if ((ep = strchr(cp, '#')) != NULL)
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*ep = '\0';
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if (!*cp || *cp == '\n')
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continue;
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nonblank++;
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snprintf(loc, sizeof(loc), "%.200s:%lu", file, linenum);
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if (check_principals_line(cp, cert, loc, authoptsp) == 0)
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found_principal = 1;
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}
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debug2_f("%s: processed %lu/%lu lines", file, nonblank, linenum);
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free(line);
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return found_principal;
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}
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/* XXX remove pw args here and elsewhere once ssh->authctxt is guaranteed */
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static int
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match_principals_file(struct passwd *pw, char *file,
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struct sshkey_cert *cert, struct sshauthopt **authoptsp)
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@ -451,7 +335,7 @@ match_principals_file(struct passwd *pw, char *file,
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restore_uid();
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return 0;
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}
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success = process_principals(f, file, cert, authoptsp);
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success = auth_process_principals(f, file, cert, authoptsp);
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fclose(f);
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restore_uid();
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return success;
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@ -567,7 +451,7 @@ match_principals_command(struct passwd *user_pw,
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uid_swapped = 1;
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temporarily_use_uid(runas_pw);
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ok = process_principals(f, "(command)", cert, authoptsp);
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ok = auth_process_principals(f, "(command)", cert, authoptsp);
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fclose(f);
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f = NULL;
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@ -595,189 +479,6 @@ match_principals_command(struct passwd *user_pw,
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return found_principal;
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}
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/*
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* Check a single line of an authorized_keys-format file. Returns 0 if key
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* matches, -1 otherwise. Will return key/cert options via *authoptsp
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* on success. "loc" is used as file/line location in log messages.
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*/
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static int
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check_authkey_line(struct passwd *pw, struct sshkey *key,
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char *cp, const char *remote_ip, const char *remote_host, const char *loc,
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struct sshauthopt **authoptsp)
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{
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int want_keytype = sshkey_is_cert(key) ? KEY_UNSPEC : key->type;
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struct sshkey *found = NULL;
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struct sshauthopt *keyopts = NULL, *certopts = NULL, *finalopts = NULL;
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char *key_options = NULL, *fp = NULL;
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const char *reason = NULL;
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int ret = -1;
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if (authoptsp != NULL)
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*authoptsp = NULL;
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if ((found = sshkey_new(want_keytype)) == NULL) {
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debug3_f("keytype %d failed", want_keytype);
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goto out;
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}
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/* XXX djm: peek at key type in line and skip if unwanted */
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if (sshkey_read(found, &cp) != 0) {
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/* no key? check for options */
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debug2("%s: check options: '%s'", loc, cp);
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key_options = cp;
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if (sshkey_advance_past_options(&cp) != 0) {
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reason = "invalid key option string";
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goto fail_reason;
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}
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skip_space(&cp);
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if (sshkey_read(found, &cp) != 0) {
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/* still no key? advance to next line*/
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debug2("%s: advance: '%s'", loc, cp);
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goto out;
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}
|
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}
|
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/* Parse key options now; we need to know if this is a CA key */
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if ((keyopts = sshauthopt_parse(key_options, &reason)) == NULL) {
|
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debug("%s: bad key options: %s", loc, reason);
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auth_debug_add("%s: bad key options: %s", loc, reason);
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goto out;
|
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}
|
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/* Ignore keys that don't match or incorrectly marked as CAs */
|
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if (sshkey_is_cert(key)) {
|
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/* Certificate; check signature key against CA */
|
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if (!sshkey_equal(found, key->cert->signature_key) ||
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!keyopts->cert_authority)
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goto out;
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} else {
|
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/* Plain key: check it against key found in file */
|
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if (!sshkey_equal(found, key) || keyopts->cert_authority)
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goto out;
|
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}
|
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|
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/* We have a candidate key, perform authorisation checks */
|
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if ((fp = sshkey_fingerprint(found,
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options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
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fatal_f("fingerprint failed");
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debug("%s: matching %s found: %s %s", loc,
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sshkey_is_cert(key) ? "CA" : "key", sshkey_type(found), fp);
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if (auth_authorise_keyopts(pw, keyopts,
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sshkey_is_cert(key), remote_ip, remote_host, loc) != 0) {
|
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reason = "Refused by key options";
|
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goto fail_reason;
|
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}
|
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/* That's all we need for plain keys. */
|
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if (!sshkey_is_cert(key)) {
|
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verbose("Accepted key %s %s found at %s",
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sshkey_type(found), fp, loc);
|
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finalopts = keyopts;
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keyopts = NULL;
|
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goto success;
|
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}
|
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|
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/*
|
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* Additional authorisation for certificates.
|
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*/
|
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|
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/* Parse and check options present in certificate */
|
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if ((certopts = sshauthopt_from_cert(key)) == NULL) {
|
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reason = "Invalid certificate options";
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goto fail_reason;
|
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}
|
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if (auth_authorise_keyopts(pw, certopts, 0,
|
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remote_ip, remote_host, loc) != 0) {
|
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reason = "Refused by certificate options";
|
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goto fail_reason;
|
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}
|
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if ((finalopts = sshauthopt_merge(keyopts, certopts, &reason)) == NULL)
|
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goto fail_reason;
|
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|
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/*
|
||||
* If the user has specified a list of principals as
|
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* a key option, then prefer that list to matching
|
||||
* their username in the certificate principals list.
|
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*/
|
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if (keyopts->cert_principals != NULL &&
|
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!match_principals_option(keyopts->cert_principals, key->cert)) {
|
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reason = "Certificate does not contain an authorized principal";
|
||||
goto fail_reason;
|
||||
}
|
||||
if (sshkey_cert_check_authority_now(key, 0, 0, 0,
|
||||
keyopts->cert_principals == NULL ? pw->pw_name : NULL,
|
||||
&reason) != 0)
|
||||
goto fail_reason;
|
||||
|
||||
verbose("Accepted certificate ID \"%s\" (serial %llu) "
|
||||
"signed by CA %s %s found at %s",
|
||||
key->cert->key_id,
|
||||
(unsigned long long)key->cert->serial,
|
||||
sshkey_type(found), fp, loc);
|
||||
|
||||
success:
|
||||
if (finalopts == NULL)
|
||||
fatal_f("internal error: missing options");
|
||||
if (authoptsp != NULL) {
|
||||
*authoptsp = finalopts;
|
||||
finalopts = NULL;
|
||||
}
|
||||
/* success */
|
||||
ret = 0;
|
||||
goto out;
|
||||
|
||||
fail_reason:
|
||||
error("%s", reason);
|
||||
auth_debug_add("%s", reason);
|
||||
out:
|
||||
free(fp);
|
||||
sshauthopt_free(keyopts);
|
||||
sshauthopt_free(certopts);
|
||||
sshauthopt_free(finalopts);
|
||||
sshkey_free(found);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/*
|
||||
* Checks whether key is allowed in authorized_keys-format file,
|
||||
* returns 1 if the key is allowed or 0 otherwise.
|
||||
*/
|
||||
static int
|
||||
check_authkeys_file(struct passwd *pw, FILE *f, char *file,
|
||||
struct sshkey *key, const char *remote_ip,
|
||||
const char *remote_host, struct sshauthopt **authoptsp)
|
||||
{
|
||||
char *cp, *line = NULL, loc[256];
|
||||
size_t linesize = 0;
|
||||
int found_key = 0;
|
||||
u_long linenum = 0, nonblank = 0;
|
||||
|
||||
if (authoptsp != NULL)
|
||||
*authoptsp = NULL;
|
||||
|
||||
while (getline(&line, &linesize, f) != -1) {
|
||||
linenum++;
|
||||
/* Always consume entire file */
|
||||
if (found_key)
|
||||
continue;
|
||||
|
||||
/* Skip leading whitespace, empty and comment lines. */
|
||||
cp = line;
|
||||
skip_space(&cp);
|
||||
if (!*cp || *cp == '\n' || *cp == '#')
|
||||
continue;
|
||||
|
||||
nonblank++;
|
||||
snprintf(loc, sizeof(loc), "%.200s:%lu", file, linenum);
|
||||
if (check_authkey_line(pw, key, cp,
|
||||
remote_ip, remote_host, loc, authoptsp) == 0)
|
||||
found_key = 1;
|
||||
}
|
||||
free(line);
|
||||
debug2_f("%s: processed %lu/%lu lines", file, nonblank, linenum);
|
||||
return found_key;
|
||||
}
|
||||
|
||||
/* Authenticate a certificate key against TrustedUserCAKeys */
|
||||
static int
|
||||
user_cert_trusted_ca(struct passwd *pw, struct sshkey *key,
|
||||
@ -902,7 +603,7 @@ user_key_allowed2(struct passwd *pw, struct sshkey *key,
|
||||
|
||||
debug("trying public key file %s", file);
|
||||
if ((f = auth_openkeyfile(file, pw, options.strict_modes)) != NULL) {
|
||||
found_key = check_authkeys_file(pw, f, file,
|
||||
found_key = auth_check_authkeys_file(pw, f, file,
|
||||
key, remote_ip, remote_host, authoptsp);
|
||||
fclose(f);
|
||||
}
|
||||
@ -1018,7 +719,7 @@ user_key_command_allowed2(struct passwd *user_pw, struct sshkey *key,
|
||||
uid_swapped = 1;
|
||||
temporarily_use_uid(runas_pw);
|
||||
|
||||
ok = check_authkeys_file(user_pw, f,
|
||||
ok = auth_check_authkeys_file(user_pw, f,
|
||||
options.authorized_keys_command, key, remote_ip,
|
||||
remote_host, authoptsp);
|
||||
|
||||
|
||||
442
auth2-pubkeyfile.c
Normal file
442
auth2-pubkeyfile.c
Normal file
@ -0,0 +1,442 @@
|
||||
/* $OpenBSD: auth2-pubkeyfile.c,v 1.1 2022/05/27 05:02:46 djm Exp $ */
|
||||
/*
|
||||
* Copyright (c) 2000 Markus Friedl. All rights reserved.
|
||||
* Copyright (c) 2010 Damien Miller. All rights reserved.
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* 1. Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* 2. Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in the
|
||||
* documentation and/or other materials provided with the distribution.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
||||
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
||||
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
||||
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
||||
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
||||
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
||||
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
||||
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
||||
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
*/
|
||||
|
||||
#include "includes.h"
|
||||
|
||||
#include <sys/types.h>
|
||||
#include <sys/stat.h>
|
||||
|
||||
#include <stdlib.h>
|
||||
#include <errno.h>
|
||||
#include <fcntl.h>
|
||||
#include <pwd.h>
|
||||
#include <stdio.h>
|
||||
#include <stdarg.h>
|
||||
#include <string.h>
|
||||
#include <time.h>
|
||||
#include <unistd.h>
|
||||
|
||||
#include "ssh.h"
|
||||
#include "log.h"
|
||||
#include "misc.h"
|
||||
#include "compat.h"
|
||||
#include "sshkey.h"
|
||||
#include "digest.h"
|
||||
#include "hostfile.h"
|
||||
#include "auth.h"
|
||||
#include "auth-options.h"
|
||||
#include "authfile.h"
|
||||
#include "match.h"
|
||||
#include "ssherr.h"
|
||||
|
||||
int
|
||||
auth_authorise_keyopts(struct passwd *pw, struct sshauthopt *opts,
|
||||
int allow_cert_authority, const char *remote_ip, const char *remote_host,
|
||||
const char *loc)
|
||||
{
|
||||
time_t now = time(NULL);
|
||||
char buf[64];
|
||||
|
||||
/*
|
||||
* Check keys/principals file expiry time.
|
||||
* NB. validity interval in certificate is handled elsewhere.
|
||||
*/
|
||||
if (opts->valid_before && now > 0 &&
|
||||
opts->valid_before < (uint64_t)now) {
|
||||
format_absolute_time(opts->valid_before, buf, sizeof(buf));
|
||||
debug("%s: entry expired at %s", loc, buf);
|
||||
auth_debug_add("%s: entry expired at %s", loc, buf);
|
||||
return -1;
|
||||
}
|
||||
/* Consistency checks */
|
||||
if (opts->cert_principals != NULL && !opts->cert_authority) {
|
||||
debug("%s: principals on non-CA key", loc);
|
||||
auth_debug_add("%s: principals on non-CA key", loc);
|
||||
/* deny access */
|
||||
return -1;
|
||||
}
|
||||
/* cert-authority flag isn't valid in authorized_principals files */
|
||||
if (!allow_cert_authority && opts->cert_authority) {
|
||||
debug("%s: cert-authority flag invalid here", loc);
|
||||
auth_debug_add("%s: cert-authority flag invalid here", loc);
|
||||
/* deny access */
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* Perform from= checks */
|
||||
if (opts->required_from_host_keys != NULL) {
|
||||
switch (match_host_and_ip(remote_host, remote_ip,
|
||||
opts->required_from_host_keys )) {
|
||||
case 1:
|
||||
/* Host name matches. */
|
||||
break;
|
||||
case -1:
|
||||
default:
|
||||
debug("%s: invalid from criteria", loc);
|
||||
auth_debug_add("%s: invalid from criteria", loc);
|
||||
/* FALLTHROUGH */
|
||||
case 0:
|
||||
logit("%s: Authentication tried for %.100s with "
|
||||
"correct key but not from a permitted "
|
||||
"host (host=%.200s, ip=%.200s, required=%.200s).",
|
||||
loc, pw->pw_name, remote_host, remote_ip,
|
||||
opts->required_from_host_keys);
|
||||
auth_debug_add("%s: Your host '%.200s' is not "
|
||||
"permitted to use this key for login.",
|
||||
loc, remote_host);
|
||||
/* deny access */
|
||||
return -1;
|
||||
}
|
||||
}
|
||||
/* Check source-address restriction from certificate */
|
||||
if (opts->required_from_host_cert != NULL) {
|
||||
switch (addr_match_cidr_list(remote_ip,
|
||||
opts->required_from_host_cert)) {
|
||||
case 1:
|
||||
/* accepted */
|
||||
break;
|
||||
case -1:
|
||||
default:
|
||||
/* invalid */
|
||||
error("%s: Certificate source-address invalid", loc);
|
||||
/* FALLTHROUGH */
|
||||
case 0:
|
||||
logit("%s: Authentication tried for %.100s with valid "
|
||||
"certificate but not from a permitted source "
|
||||
"address (%.200s).", loc, pw->pw_name, remote_ip);
|
||||
auth_debug_add("%s: Your address '%.200s' is not "
|
||||
"permitted to use this certificate for login.",
|
||||
loc, remote_ip);
|
||||
return -1;
|
||||
}
|
||||
}
|
||||
/*
|
||||
*
|
||||
* XXX this is spammy. We should report remotely only for keys
|
||||
* that are successful in actual auth attempts, and not PK_OK
|
||||
* tests.
|
||||
*/
|
||||
auth_log_authopts(loc, opts, 1);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int
|
||||
match_principals_option(const char *principal_list, struct sshkey_cert *cert)
|
||||
{
|
||||
char *result;
|
||||
u_int i;
|
||||
|
||||
/* XXX percent_expand() sequences for authorized_principals? */
|
||||
|
||||
for (i = 0; i < cert->nprincipals; i++) {
|
||||
if ((result = match_list(cert->principals[i],
|
||||
principal_list, NULL)) != NULL) {
|
||||
debug3("matched principal from key options \"%.100s\"",
|
||||
result);
|
||||
free(result);
|
||||
return 1;
|
||||
}
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Process a single authorized_principals format line. Returns 0 and sets
|
||||
* authoptsp is principal is authorised, -1 otherwise. "loc" is used as a
|
||||
* log preamble for file/line information.
|
||||
*/
|
||||
int
|
||||
auth_check_principals_line(char *cp, const struct sshkey_cert *cert,
|
||||
const char *loc, struct sshauthopt **authoptsp)
|
||||
{
|
||||
u_int i, found = 0;
|
||||
char *ep, *line_opts;
|
||||
const char *reason = NULL;
|
||||
struct sshauthopt *opts = NULL;
|
||||
|
||||
if (authoptsp != NULL)
|
||||
*authoptsp = NULL;
|
||||
|
||||
/* Trim trailing whitespace. */
|
||||
ep = cp + strlen(cp) - 1;
|
||||
while (ep > cp && (*ep == '\n' || *ep == ' ' || *ep == '\t'))
|
||||
*ep-- = '\0';
|
||||
|
||||
/*
|
||||
* If the line has internal whitespace then assume it has
|
||||
* key options.
|
||||
*/
|
||||
line_opts = NULL;
|
||||
if ((ep = strrchr(cp, ' ')) != NULL ||
|
||||
(ep = strrchr(cp, '\t')) != NULL) {
|
||||
for (; *ep == ' ' || *ep == '\t'; ep++)
|
||||
;
|
||||
line_opts = cp;
|
||||
cp = ep;
|
||||
}
|
||||
if ((opts = sshauthopt_parse(line_opts, &reason)) == NULL) {
|
||||
debug("%s: bad principals options: %s", loc, reason);
|
||||
auth_debug_add("%s: bad principals options: %s", loc, reason);
|
||||
return -1;
|
||||
}
|
||||
/* Check principals in cert against those on line */
|
||||
for (i = 0; i < cert->nprincipals; i++) {
|
||||
if (strcmp(cp, cert->principals[i]) != 0)
|
||||
continue;
|
||||
debug3("%s: matched principal \"%.100s\"",
|
||||
loc, cert->principals[i]);
|
||||
found = 1;
|
||||
}
|
||||
if (found && authoptsp != NULL) {
|
||||
*authoptsp = opts;
|
||||
opts = NULL;
|
||||
}
|
||||
sshauthopt_free(opts);
|
||||
return found ? 0 : -1;
|
||||
}
|
||||
|
||||
int
|
||||
auth_process_principals(FILE *f, const char *file,
|
||||
const struct sshkey_cert *cert, struct sshauthopt **authoptsp)
|
||||
{
|
||||
char loc[256], *line = NULL, *cp, *ep;
|
||||
size_t linesize = 0;
|
||||
u_long linenum = 0, nonblank = 0;
|
||||
u_int found_principal = 0;
|
||||
|
||||
if (authoptsp != NULL)
|
||||
*authoptsp = NULL;
|
||||
|
||||
while (getline(&line, &linesize, f) != -1) {
|
||||
linenum++;
|
||||
/* Always consume entire input */
|
||||
if (found_principal)
|
||||
continue;
|
||||
|
||||
/* Skip leading whitespace. */
|
||||
for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
|
||||
;
|
||||
/* Skip blank and comment lines. */
|
||||
if ((ep = strchr(cp, '#')) != NULL)
|
||||
*ep = '\0';
|
||||
if (!*cp || *cp == '\n')
|
||||
continue;
|
||||
|
||||
nonblank++;
|
||||
snprintf(loc, sizeof(loc), "%.200s:%lu", file, linenum);
|
||||
if (auth_check_principals_line(cp, cert, loc, authoptsp) == 0)
|
||||
found_principal = 1;
|
||||
}
|
||||
debug2_f("%s: processed %lu/%lu lines", file, nonblank, linenum);
|
||||
free(line);
|
||||
return found_principal;
|
||||
}
|
||||
|
||||
/*
|
||||
* Check a single line of an authorized_keys-format file. Returns 0 if key
|
||||
* matches, -1 otherwise. Will return key/cert options via *authoptsp
|
||||
* on success. "loc" is used as file/line location in log messages.
|
||||
*/
|
||||
int
|
||||
auth_check_authkey_line(struct passwd *pw, struct sshkey *key,
|
||||
char *cp, const char *remote_ip, const char *remote_host, const char *loc,
|
||||
struct sshauthopt **authoptsp)
|
||||
{
|
||||
int want_keytype = sshkey_is_cert(key) ? KEY_UNSPEC : key->type;
|
||||
struct sshkey *found = NULL;
|
||||
struct sshauthopt *keyopts = NULL, *certopts = NULL, *finalopts = NULL;
|
||||
char *key_options = NULL, *fp = NULL;
|
||||
const char *reason = NULL;
|
||||
int ret = -1;
|
||||
|
||||
if (authoptsp != NULL)
|
||||
*authoptsp = NULL;
|
||||
|
||||
if ((found = sshkey_new(want_keytype)) == NULL) {
|
||||
debug3_f("keytype %d failed", want_keytype);
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* XXX djm: peek at key type in line and skip if unwanted */
|
||||
|
||||
if (sshkey_read(found, &cp) != 0) {
|
||||
/* no key? check for options */
|
||||
debug2("%s: check options: '%s'", loc, cp);
|
||||
key_options = cp;
|
||||
if (sshkey_advance_past_options(&cp) != 0) {
|
||||
reason = "invalid key option string";
|
||||
goto fail_reason;
|
||||
}
|
||||
skip_space(&cp);
|
||||
if (sshkey_read(found, &cp) != 0) {
|
||||
/* still no key? advance to next line*/
|
||||
debug2("%s: advance: '%s'", loc, cp);
|
||||
goto out;
|
||||
}
|
||||
}
|
||||
/* Parse key options now; we need to know if this is a CA key */
|
||||
if ((keyopts = sshauthopt_parse(key_options, &reason)) == NULL) {
|
||||
debug("%s: bad key options: %s", loc, reason);
|
||||
auth_debug_add("%s: bad key options: %s", loc, reason);
|
||||
goto out;
|
||||
}
|
||||
/* Ignore keys that don't match or incorrectly marked as CAs */
|
||||
if (sshkey_is_cert(key)) {
|
||||
/* Certificate; check signature key against CA */
|
||||
if (!sshkey_equal(found, key->cert->signature_key) ||
|
||||
!keyopts->cert_authority)
|
||||
goto out;
|
||||
} else {
|
||||
/* Plain key: check it against key found in file */
|
||||
if (!sshkey_equal(found, key) || keyopts->cert_authority)
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* We have a candidate key, perform authorisation checks */
|
||||
if ((fp = sshkey_fingerprint(found,
|
||||
SSH_FP_HASH_DEFAULT, SSH_FP_DEFAULT)) == NULL)
|
||||
fatal_f("fingerprint failed");
|
||||
|
||||
debug("%s: matching %s found: %s %s", loc,
|
||||
sshkey_is_cert(key) ? "CA" : "key", sshkey_type(found), fp);
|
||||
|
||||
if (auth_authorise_keyopts(pw, keyopts,
|
||||
sshkey_is_cert(key), remote_ip, remote_host, loc) != 0) {
|
||||
reason = "Refused by key options";
|
||||
goto fail_reason;
|
||||
}
|
||||
/* That's all we need for plain keys. */
|
||||
if (!sshkey_is_cert(key)) {
|
||||
verbose("Accepted key %s %s found at %s",
|
||||
sshkey_type(found), fp, loc);
|
||||
finalopts = keyopts;
|
||||
keyopts = NULL;
|
||||
goto success;
|
||||
}
|
||||
|
||||
/*
|
||||
* Additional authorisation for certificates.
|
||||
*/
|
||||
|
||||
/* Parse and check options present in certificate */
|
||||
if ((certopts = sshauthopt_from_cert(key)) == NULL) {
|
||||
reason = "Invalid certificate options";
|
||||
goto fail_reason;
|
||||
}
|
||||
if (auth_authorise_keyopts(pw, certopts, 0,
|
||||
remote_ip, remote_host, loc) != 0) {
|
||||
reason = "Refused by certificate options";
|
||||
goto fail_reason;
|
||||
}
|
||||
if ((finalopts = sshauthopt_merge(keyopts, certopts, &reason)) == NULL)
|
||||
goto fail_reason;
|
||||
|
||||
/*
|
||||
* If the user has specified a list of principals as
|
||||
* a key option, then prefer that list to matching
|
||||
* their username in the certificate principals list.
|
||||
*/
|
||||
if (keyopts->cert_principals != NULL &&
|
||||
!match_principals_option(keyopts->cert_principals, key->cert)) {
|
||||
reason = "Certificate does not contain an authorized principal";
|
||||
goto fail_reason;
|
||||
}
|
||||
if (sshkey_cert_check_authority_now(key, 0, 0, 0,
|
||||
keyopts->cert_principals == NULL ? pw->pw_name : NULL,
|
||||
&reason) != 0)
|
||||
goto fail_reason;
|
||||
|
||||
verbose("Accepted certificate ID \"%s\" (serial %llu) "
|
||||
"signed by CA %s %s found at %s",
|
||||
key->cert->key_id,
|
||||
(unsigned long long)key->cert->serial,
|
||||
sshkey_type(found), fp, loc);
|
||||
|
||||
success:
|
||||
if (finalopts == NULL)
|
||||
fatal_f("internal error: missing options");
|
||||
if (authoptsp != NULL) {
|
||||
*authoptsp = finalopts;
|
||||
finalopts = NULL;
|
||||
}
|
||||
/* success */
|
||||
ret = 0;
|
||||
goto out;
|
||||
|
||||
fail_reason:
|
||||
error("%s", reason);
|
||||
auth_debug_add("%s", reason);
|
||||
out:
|
||||
free(fp);
|
||||
sshauthopt_free(keyopts);
|
||||
sshauthopt_free(certopts);
|
||||
sshauthopt_free(finalopts);
|
||||
sshkey_free(found);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/*
|
||||
* Checks whether key is allowed in authorized_keys-format file,
|
||||
* returns 1 if the key is allowed or 0 otherwise.
|
||||
*/
|
||||
int
|
||||
auth_check_authkeys_file(struct passwd *pw, FILE *f, char *file,
|
||||
struct sshkey *key, const char *remote_ip,
|
||||
const char *remote_host, struct sshauthopt **authoptsp)
|
||||
{
|
||||
char *cp, *line = NULL, loc[256];
|
||||
size_t linesize = 0;
|
||||
int found_key = 0;
|
||||
u_long linenum = 0, nonblank = 0;
|
||||
|
||||
if (authoptsp != NULL)
|
||||
*authoptsp = NULL;
|
||||
|
||||
while (getline(&line, &linesize, f) != -1) {
|
||||
linenum++;
|
||||
/* Always consume entire file */
|
||||
if (found_key)
|
||||
continue;
|
||||
|
||||
/* Skip leading whitespace, empty and comment lines. */
|
||||
cp = line;
|
||||
skip_space(&cp);
|
||||
if (!*cp || *cp == '\n' || *cp == '#')
|
||||
continue;
|
||||
|
||||
nonblank++;
|
||||
snprintf(loc, sizeof(loc), "%.200s:%lu", file, linenum);
|
||||
if (auth_check_authkey_line(pw, key, cp,
|
||||
remote_ip, remote_host, loc, authoptsp) == 0)
|
||||
found_key = 1;
|
||||
}
|
||||
free(line);
|
||||
debug2_f("%s: processed %lu/%lu lines", file, nonblank, linenum);
|
||||
return found_key;
|
||||
}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user