From 25505898530a333011f4fd5cbc841ad6b26c089c Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 16:40:04 +0200 Subject: Adding upstream version 1:9.2p1. Signed-off-by: Daniel Baumann --- auth-krb5.c | 273 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 273 insertions(+) create mode 100644 auth-krb5.c (limited to 'auth-krb5.c') diff --git a/auth-krb5.c b/auth-krb5.c new file mode 100644 index 0000000..c99e4e4 --- /dev/null +++ b/auth-krb5.c @@ -0,0 +1,273 @@ +/* $OpenBSD: auth-krb5.c,v 1.24 2021/04/03 06:18:40 djm Exp $ */ +/* + * Kerberos v5 authentication and ticket-passing routines. + * + * From: FreeBSD: src/crypto/openssh/auth-krb5.c,v 1.6 2001/02/13 16:58:04 assar + */ +/* + * Copyright (c) 2002 Daniel Kouril. 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 +#include +#include + +#include "xmalloc.h" +#include "ssh.h" +#include "packet.h" +#include "log.h" +#include "sshbuf.h" +#include "sshkey.h" +#include "misc.h" +#include "servconf.h" +#include "uidswap.h" +#include "hostfile.h" +#include "auth.h" + +#ifdef KRB5 +#include +#include +#include +#include + +extern ServerOptions options; + +static int +krb5_init(void *context) +{ + Authctxt *authctxt = (Authctxt *)context; + krb5_error_code problem; + + if (authctxt->krb5_ctx == NULL) { + problem = krb5_init_context(&authctxt->krb5_ctx); + if (problem) + return (problem); + } + return (0); +} + +int +auth_krb5_password(Authctxt *authctxt, const char *password) +{ +#ifndef HEIMDAL + krb5_creds creds; + krb5_principal server; +#endif + krb5_error_code problem; + krb5_ccache ccache = NULL; + int len; + char *client, *platform_client; + const char *errmsg; + + /* get platform-specific kerberos client principal name (if it exists) */ + platform_client = platform_krb5_get_principal_name(authctxt->pw->pw_name); + client = platform_client ? platform_client : authctxt->pw->pw_name; + + temporarily_use_uid(authctxt->pw); + + problem = krb5_init(authctxt); + if (problem) + goto out; + + problem = krb5_parse_name(authctxt->krb5_ctx, client, + &authctxt->krb5_user); + if (problem) + goto out; + +#ifdef HEIMDAL +# ifdef HAVE_KRB5_CC_NEW_UNIQUE + problem = krb5_cc_new_unique(authctxt->krb5_ctx, + krb5_mcc_ops.prefix, NULL, &ccache); +# else + problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops, &ccache); +# endif + if (problem) + goto out; + + problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache, + authctxt->krb5_user); + if (problem) + goto out; + + restore_uid(); + + problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user, + ccache, password, 1, NULL); + + temporarily_use_uid(authctxt->pw); + + if (problem) + goto out; + +# ifdef HAVE_KRB5_CC_NEW_UNIQUE + problem = krb5_cc_new_unique(authctxt->krb5_ctx, + krb5_fcc_ops.prefix, NULL, &authctxt->krb5_fwd_ccache); +# else + problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, + &authctxt->krb5_fwd_ccache); +# endif + if (problem) + goto out; + + problem = krb5_cc_copy_cache(authctxt->krb5_ctx, ccache, + authctxt->krb5_fwd_ccache); + krb5_cc_destroy(authctxt->krb5_ctx, ccache); + ccache = NULL; + if (problem) + goto out; + +#else + problem = krb5_get_init_creds_password(authctxt->krb5_ctx, &creds, + authctxt->krb5_user, (char *)password, NULL, NULL, 0, NULL, NULL); + if (problem) + goto out; + + problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL, + KRB5_NT_SRV_HST, &server); + if (problem) + goto out; + + restore_uid(); + problem = krb5_verify_init_creds(authctxt->krb5_ctx, &creds, server, + NULL, NULL, NULL); + krb5_free_principal(authctxt->krb5_ctx, server); + temporarily_use_uid(authctxt->pw); + if (problem) + goto out; + + if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user, + authctxt->pw->pw_name)) { + problem = -1; + goto out; + } + + problem = ssh_krb5_cc_gen(authctxt->krb5_ctx, + &authctxt->krb5_fwd_ccache); + if (problem) + goto out; + + problem = krb5_cc_initialize(authctxt->krb5_ctx, + authctxt->krb5_fwd_ccache, authctxt->krb5_user); + if (problem) + goto out; + + problem = krb5_cc_store_cred(authctxt->krb5_ctx, + authctxt->krb5_fwd_ccache, &creds); + if (problem) + goto out; +#endif + + authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); + + len = strlen(authctxt->krb5_ticket_file) + 6; + authctxt->krb5_ccname = xmalloc(len); + snprintf(authctxt->krb5_ccname, len, "FILE:%s", + authctxt->krb5_ticket_file); + +#ifdef USE_PAM + if (options.use_pam) + do_pam_putenv("KRB5CCNAME", authctxt->krb5_ccname); +#endif + + out: + restore_uid(); + + free(platform_client); + + if (problem) { + if (ccache) + krb5_cc_destroy(authctxt->krb5_ctx, ccache); + + if (authctxt->krb5_ctx != NULL && problem!=-1) { + errmsg = krb5_get_error_message(authctxt->krb5_ctx, + problem); + debug("Kerberos password authentication failed: %s", + errmsg); + krb5_free_error_message(authctxt->krb5_ctx, errmsg); + } else + debug("Kerberos password authentication failed: %d", + problem); + + krb5_cleanup_proc(authctxt); + + if (options.kerberos_or_local_passwd) + return (-1); + else + return (0); + } + return (authctxt->valid ? 1 : 0); +} + +void +krb5_cleanup_proc(Authctxt *authctxt) +{ + debug("krb5_cleanup_proc called"); + if (authctxt->krb5_fwd_ccache) { + krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); + authctxt->krb5_fwd_ccache = NULL; + } + if (authctxt->krb5_user) { + krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user); + authctxt->krb5_user = NULL; + } + if (authctxt->krb5_ctx) { + krb5_free_context(authctxt->krb5_ctx); + authctxt->krb5_ctx = NULL; + } +} + +#ifndef HEIMDAL +krb5_error_code +ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) { + int tmpfd, ret, oerrno; + char ccname[40]; + mode_t old_umask; + + ret = snprintf(ccname, sizeof(ccname), + "FILE:/tmp/krb5cc_%d_XXXXXXXXXX", geteuid()); + if (ret < 0 || (size_t)ret >= sizeof(ccname)) + return ENOMEM; + + old_umask = umask(0177); + tmpfd = mkstemp(ccname + strlen("FILE:")); + oerrno = errno; + umask(old_umask); + if (tmpfd == -1) { + logit("mkstemp(): %.100s", strerror(oerrno)); + return oerrno; + } + + if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) { + oerrno = errno; + logit("fchmod(): %.100s", strerror(oerrno)); + close(tmpfd); + return oerrno; + } + close(tmpfd); + + return (krb5_cc_resolve(ctx, ccname, ccache)); +} +#endif /* !HEIMDAL */ +#endif /* KRB5 */ -- cgit v1.2.3