auth-krb5.c revision 128460
1/* 2 * Kerberos v5 authentication and ticket-passing routines. 3 * 4 * $xFreeBSD: src/crypto/openssh/auth-krb5.c,v 1.6 2001/02/13 16:58:04 assar Exp$ 5 */ 6/* 7 * Copyright (c) 2002 Daniel Kouril. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30#include "includes.h" 31RCSID("$OpenBSD: auth-krb5.c,v 1.15 2003/11/21 11:57:02 djm Exp $"); 32RCSID("$FreeBSD: head/crypto/openssh/auth-krb5.c 128460 2004-04-20 09:46:41Z des $"); 33 34#include "ssh.h" 35#include "ssh1.h" 36#include "packet.h" 37#include "xmalloc.h" 38#include "log.h" 39#include "servconf.h" 40#include "uidswap.h" 41#include "auth.h" 42 43#ifdef KRB5 44#include <krb5.h> 45 46extern ServerOptions options; 47 48static int 49krb5_init(void *context) 50{ 51 Authctxt *authctxt = (Authctxt *)context; 52 krb5_error_code problem; 53 54 if (authctxt->krb5_ctx == NULL) { 55 problem = krb5_init_context(&authctxt->krb5_ctx); 56 if (problem) 57 return (problem); 58#ifdef KRB5_INIT_ETS 59 krb5_init_ets(authctxt->krb5_ctx); 60#endif 61 } 62 return (0); 63} 64 65int 66auth_krb5_password(Authctxt *authctxt, const char *password) 67{ 68#ifndef HEIMDAL 69 krb5_creds creds; 70 krb5_principal server; 71 char ccname[40]; 72 int tmpfd; 73#endif 74 krb5_error_code problem; 75 krb5_ccache ccache = NULL; 76 int len; 77 78 if (!authctxt->valid) 79 return (0); 80 81 temporarily_use_uid(authctxt->pw); 82 83 problem = krb5_init(authctxt); 84 if (problem) 85 goto out; 86 87 problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name, 88 &authctxt->krb5_user); 89 if (problem) 90 goto out; 91 92#ifdef HEIMDAL 93 problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops, &ccache); 94 if (problem) 95 goto out; 96 97 problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache, 98 authctxt->krb5_user); 99 if (problem) 100 goto out; 101 102 restore_uid(); 103 104 problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user, 105 ccache, password, 1, NULL); 106 107 temporarily_use_uid(authctxt->pw); 108 109 if (problem) 110 goto out; 111 112 problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, 113 &authctxt->krb5_fwd_ccache); 114 if (problem) 115 goto out; 116 117 problem = krb5_cc_copy_cache(authctxt->krb5_ctx, ccache, 118 authctxt->krb5_fwd_ccache); 119 krb5_cc_destroy(authctxt->krb5_ctx, ccache); 120 ccache = NULL; 121 if (problem) 122 goto out; 123 124#else 125 problem = krb5_get_init_creds_password(authctxt->krb5_ctx, &creds, 126 authctxt->krb5_user, (char *)password, NULL, NULL, 0, NULL, NULL); 127 if (problem) 128 goto out; 129 130 problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL, 131 KRB5_NT_SRV_HST, &server); 132 if (problem) 133 goto out; 134 135 restore_uid(); 136 problem = krb5_verify_init_creds(authctxt->krb5_ctx, &creds, server, 137 NULL, NULL, NULL); 138 krb5_free_principal(authctxt->krb5_ctx, server); 139 temporarily_use_uid(authctxt->pw); 140 if (problem) 141 goto out; 142 143 if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user, 144 authctxt->pw->pw_name)) { 145 problem = -1; 146 goto out; 147 } 148 149 snprintf(ccname,sizeof(ccname),"FILE:/tmp/krb5cc_%d_XXXXXX",geteuid()); 150 151 if ((tmpfd = mkstemp(ccname+strlen("FILE:")))==-1) { 152 logit("mkstemp(): %.100s", strerror(errno)); 153 problem = errno; 154 goto out; 155 } 156 157 if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) { 158 logit("fchmod(): %.100s", strerror(errno)); 159 close(tmpfd); 160 problem = errno; 161 goto out; 162 } 163 close(tmpfd); 164 165 problem = krb5_cc_resolve(authctxt->krb5_ctx, ccname, &authctxt->krb5_fwd_ccache); 166 if (problem) 167 goto out; 168 169 problem = krb5_cc_initialize(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache, 170 authctxt->krb5_user); 171 if (problem) 172 goto out; 173 174 problem= krb5_cc_store_cred(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache, 175 &creds); 176 if (problem) 177 goto out; 178#endif 179 180 authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); 181 182 len = strlen(authctxt->krb5_ticket_file) + 6; 183 authctxt->krb5_ccname = xmalloc(len); 184 snprintf(authctxt->krb5_ccname, len, "FILE:%s", 185 authctxt->krb5_ticket_file); 186 187 out: 188 restore_uid(); 189 190 if (problem) { 191 if (ccache) 192 krb5_cc_destroy(authctxt->krb5_ctx, ccache); 193 194 if (authctxt->krb5_ctx != NULL && problem!=-1) 195 debug("Kerberos password authentication failed: %s", 196 krb5_get_err_text(authctxt->krb5_ctx, problem)); 197 else 198 debug("Kerberos password authentication failed: %d", 199 problem); 200 201 krb5_cleanup_proc(authctxt); 202 203 if (options.kerberos_or_local_passwd) 204 return (-1); 205 else 206 return (0); 207 } 208 return (1); 209} 210 211void 212krb5_cleanup_proc(Authctxt *authctxt) 213{ 214 debug("krb5_cleanup_proc called"); 215 if (authctxt->krb5_fwd_ccache) { 216 krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); 217 authctxt->krb5_fwd_ccache = NULL; 218 } 219 if (authctxt->krb5_user) { 220 krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user); 221 authctxt->krb5_user = NULL; 222 } 223 if (authctxt->krb5_ctx) { 224 krb5_free_context(authctxt->krb5_ctx); 225 authctxt->krb5_ctx = NULL; 226 } 227} 228 229#endif /* KRB5 */ 230