1 /* $OpenBSD: auth-krb5.c,v 1.23 2018/07/09 21:35:50 markus Exp $ */ 2 /* 3 * Kerberos v5 authentication and ticket-passing routines. 4 * 5 * From: FreeBSD: src/crypto/openssh/auth-krb5.c,v 1.6 2001/02/13 16:58:04 assar 6 */ 7 /* 8 * Copyright (c) 2002 Daniel Kouril. All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #include <sys/types.h> 32 #include <pwd.h> 33 #include <stdarg.h> 34 35 #include "xmalloc.h" 36 #include "ssh.h" 37 #include "packet.h" 38 #include "log.h" 39 #include "sshbuf.h" 40 #include "sshkey.h" 41 #include "servconf.h" 42 #include "uidswap.h" 43 #include "hostfile.h" 44 #include "auth.h" 45 46 #ifdef KRB5 47 #include <krb5.h> 48 49 extern ServerOptions options; 50 51 static int 52 krb5_init(void *context) 53 { 54 Authctxt *authctxt = (Authctxt *)context; 55 krb5_error_code problem; 56 57 if (authctxt->krb5_ctx == NULL) { 58 problem = krb5_init_context(&authctxt->krb5_ctx); 59 if (problem) 60 return (problem); 61 krb5_init_ets(authctxt->krb5_ctx); 62 } 63 return (0); 64 } 65 66 int 67 auth_krb5_password(Authctxt *authctxt, const char *password) 68 { 69 krb5_error_code problem; 70 krb5_ccache ccache = NULL; 71 const char *errmsg; 72 73 temporarily_use_uid(authctxt->pw); 74 75 problem = krb5_init(authctxt); 76 if (problem) 77 goto out; 78 79 problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name, 80 &authctxt->krb5_user); 81 if (problem) 82 goto out; 83 84 problem = krb5_cc_new_unique(authctxt->krb5_ctx, 85 krb5_mcc_ops.prefix, NULL, &ccache); 86 if (problem) 87 goto out; 88 89 problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache, 90 authctxt->krb5_user); 91 if (problem) 92 goto out; 93 94 restore_uid(); 95 96 problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user, 97 ccache, password, 1, NULL); 98 99 temporarily_use_uid(authctxt->pw); 100 101 if (problem) 102 goto out; 103 104 problem = krb5_cc_new_unique(authctxt->krb5_ctx, 105 krb5_fcc_ops.prefix, NULL, &authctxt->krb5_fwd_ccache); 106 if (problem) 107 goto out; 108 109 problem = krb5_cc_copy_cache(authctxt->krb5_ctx, ccache, 110 authctxt->krb5_fwd_ccache); 111 krb5_cc_destroy(authctxt->krb5_ctx, ccache); 112 ccache = NULL; 113 if (problem) 114 goto out; 115 116 authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, 117 authctxt->krb5_fwd_ccache); 118 119 out: 120 restore_uid(); 121 122 if (problem) { 123 if (ccache) 124 krb5_cc_destroy(authctxt->krb5_ctx, ccache); 125 126 if (authctxt->krb5_ctx != NULL) { 127 errmsg = krb5_get_error_message(authctxt->krb5_ctx, 128 problem); 129 debug("Kerberos password authentication failed: %s", 130 errmsg); 131 krb5_free_error_message(authctxt->krb5_ctx, errmsg); 132 } else 133 debug("Kerberos password authentication failed: %d", 134 problem); 135 136 krb5_cleanup_proc(authctxt); 137 138 if (options.kerberos_or_local_passwd) 139 return (-1); 140 else 141 return (0); 142 } 143 return (authctxt->valid ? 1 : 0); 144 } 145 146 void 147 krb5_cleanup_proc(Authctxt *authctxt) 148 { 149 debug("krb5_cleanup_proc called"); 150 if (authctxt->krb5_fwd_ccache) { 151 krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); 152 authctxt->krb5_fwd_ccache = NULL; 153 } 154 if (authctxt->krb5_user) { 155 krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user); 156 authctxt->krb5_user = NULL; 157 } 158 if (authctxt->krb5_ctx) { 159 krb5_free_context(authctxt->krb5_ctx); 160 authctxt->krb5_ctx = NULL; 161 } 162 } 163 164 #endif /* KRB5 */ 165