Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 1 | /* $OpenBSD: gss-serv-krb5.c,v 1.1 2003/08/22 10:56:09 markus Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions |
| 8 | * are met: |
| 9 | * 1. Redistributions of source code must retain the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer. |
| 11 | * 2. Redistributions in binary form must reproduce the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer in the |
| 13 | * documentation and/or other materials provided with the distribution. |
| 14 | * |
| 15 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR |
| 16 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 17 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 18 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 19 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 20 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 21 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 22 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 23 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 24 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 25 | */ |
| 26 | |
| 27 | #include "includes.h" |
| 28 | |
| 29 | #ifdef GSSAPI |
| 30 | #ifdef KRB5 |
| 31 | |
| 32 | #include "auth.h" |
| 33 | #include "xmalloc.h" |
| 34 | #include "log.h" |
| 35 | #include "servconf.h" |
| 36 | |
| 37 | #include "ssh-gss.h" |
| 38 | |
| 39 | extern ServerOptions options; |
| 40 | |
Darren Tucker | 49aaf4a | 2003-08-26 11:58:16 +1000 | [diff] [blame] | 41 | #ifdef HEIMDAL |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 42 | #include <krb5.h> |
Darren Tucker | 49aaf4a | 2003-08-26 11:58:16 +1000 | [diff] [blame] | 43 | #else |
| 44 | #include <gssapi_krb5.h> |
| 45 | #endif |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 46 | |
| 47 | static krb5_context krb_context = NULL; |
| 48 | |
| 49 | /* Initialise the krb5 library, for the stuff that GSSAPI won't do */ |
| 50 | |
| 51 | static int |
| 52 | ssh_gssapi_krb5_init() |
| 53 | { |
| 54 | krb5_error_code problem; |
| 55 | |
| 56 | if (krb_context != NULL) |
| 57 | return 1; |
| 58 | |
| 59 | problem = krb5_init_context(&krb_context); |
| 60 | if (problem) { |
| 61 | logit("Cannot initialize krb5 context"); |
| 62 | return 0; |
| 63 | } |
| 64 | krb5_init_ets(krb_context); |
| 65 | |
| 66 | return 1; |
| 67 | } |
| 68 | |
| 69 | /* Check if this user is OK to login. This only works with krb5 - other |
| 70 | * GSSAPI mechanisms will need their own. |
| 71 | * Returns true if the user is OK to log in, otherwise returns 0 |
| 72 | */ |
| 73 | |
| 74 | static int |
| 75 | ssh_gssapi_krb5_userok(ssh_gssapi_client *client, char *name) |
| 76 | { |
| 77 | krb5_principal princ; |
| 78 | int retval; |
| 79 | |
| 80 | if (ssh_gssapi_krb5_init() == 0) |
| 81 | return 0; |
| 82 | |
| 83 | if ((retval = krb5_parse_name(krb_context, client->exportedname.value, |
| 84 | &princ))) { |
| 85 | logit("krb5_parse_name(): %.100s", |
| 86 | krb5_get_err_text(krb_context, retval)); |
| 87 | return 0; |
| 88 | } |
| 89 | if (krb5_kuserok(krb_context, princ, name)) { |
| 90 | retval = 1; |
| 91 | logit("Authorized to %s, krb5 principal %s (krb5_kuserok)", |
| 92 | name, (char *)client->displayname.value); |
| 93 | } else |
| 94 | retval = 0; |
| 95 | |
| 96 | krb5_free_principal(krb_context, princ); |
| 97 | return retval; |
| 98 | } |
| 99 | |
| 100 | |
| 101 | /* This writes out any forwarded credentials from the structure populated |
| 102 | * during userauth. Called after we have setuid to the user */ |
| 103 | |
| 104 | static void |
| 105 | ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client) |
| 106 | { |
| 107 | krb5_ccache ccache; |
| 108 | krb5_error_code problem; |
| 109 | krb5_principal princ; |
| 110 | OM_uint32 maj_status, min_status; |
| 111 | |
| 112 | if (client->creds == NULL) { |
| 113 | debug("No credentials stored"); |
| 114 | return; |
| 115 | } |
| 116 | |
| 117 | if (ssh_gssapi_krb5_init() == 0) |
| 118 | return; |
| 119 | |
Darren Tucker | 49aaf4a | 2003-08-26 11:58:16 +1000 | [diff] [blame] | 120 | #ifdef HEIMDAL |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 121 | if ((problem = krb5_cc_gen_new(krb_context, &krb5_fcc_ops, &ccache))) { |
| 122 | logit("krb5_cc_gen_new(): %.100s", |
| 123 | krb5_get_err_text(krb_context, problem)); |
| 124 | return; |
| 125 | } |
Darren Tucker | 49aaf4a | 2003-08-26 11:58:16 +1000 | [diff] [blame] | 126 | #else |
| 127 | { |
| 128 | int tmpfd; |
| 129 | char ccname[40]; |
| 130 | |
| 131 | snprintf(ccname, sizeof(ccname), |
| 132 | "FILE:/tmp/krb5cc_%d_XXXXXX", geteuid()); |
| 133 | |
| 134 | if ((tmpfd = mkstemp(ccname + strlen("FILE:"))) == -1) { |
| 135 | logit("mkstemp(): %.100s", strerror(errno)); |
| 136 | problem = errno; |
| 137 | return; |
| 138 | } |
| 139 | if (fchmod(tmpfd, S_IRUSR | S_IWUSR) == -1) { |
| 140 | logit("fchmod(): %.100s", strerror(errno)); |
| 141 | close(tmpfd); |
| 142 | problem = errno; |
| 143 | return; |
| 144 | } |
| 145 | close(tmpfd); |
| 146 | if ((problem = krb5_cc_resolve(krb_context, ccname, &ccache))) { |
| 147 | logit("krb5_cc_resolve(): %.100s", |
| 148 | krb5_get_err_text(krb_context, problem)); |
| 149 | return; |
| 150 | } |
| 151 | } |
| 152 | #endif /* #ifdef HEIMDAL */ |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 153 | |
| 154 | if ((problem = krb5_parse_name(krb_context, |
| 155 | client->exportedname.value, &princ))) { |
| 156 | logit("krb5_parse_name(): %.100s", |
| 157 | krb5_get_err_text(krb_context, problem)); |
| 158 | krb5_cc_destroy(krb_context, ccache); |
| 159 | return; |
| 160 | } |
| 161 | |
| 162 | if ((problem = krb5_cc_initialize(krb_context, ccache, princ))) { |
| 163 | logit("krb5_cc_initialize(): %.100s", |
| 164 | krb5_get_err_text(krb_context, problem)); |
| 165 | krb5_free_principal(krb_context, princ); |
| 166 | krb5_cc_destroy(krb_context, ccache); |
| 167 | return; |
| 168 | } |
| 169 | |
| 170 | krb5_free_principal(krb_context, princ); |
| 171 | |
| 172 | if ((maj_status = gss_krb5_copy_ccache(&min_status, |
| 173 | client->creds, ccache))) { |
| 174 | logit("gss_krb5_copy_ccache() failed"); |
| 175 | krb5_cc_destroy(krb_context, ccache); |
| 176 | return; |
| 177 | } |
| 178 | |
| 179 | client->store.filename = xstrdup(krb5_cc_get_name(krb_context, ccache)); |
| 180 | client->store.envvar = "KRB5CCNAME"; |
| 181 | client->store.envval = xstrdup(client->store.filename); |
| 182 | |
Darren Tucker | 49aaf4a | 2003-08-26 11:58:16 +1000 | [diff] [blame] | 183 | #ifdef USE_PAM |
| 184 | if (options.use_pam) |
| 185 | do_pam_putenv(client->store.envvar,client->store.envval); |
| 186 | #endif |
| 187 | |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 188 | krb5_cc_close(krb_context, ccache); |
| 189 | |
| 190 | return; |
| 191 | } |
| 192 | |
| 193 | ssh_gssapi_mech gssapi_kerberos_mech = { |
| 194 | "toWM5Slw5Ew8Mqkay+al2g==", |
| 195 | "Kerberos", |
| 196 | {9, "\x2A\x86\x48\x86\xF7\x12\x01\x02\x02"}, |
| 197 | NULL, |
| 198 | &ssh_gssapi_krb5_userok, |
| 199 | NULL, |
| 200 | &ssh_gssapi_krb5_storecreds |
| 201 | }; |
| 202 | |
| 203 | #endif /* KRB5 */ |
| 204 | |
| 205 | #endif /* GSSAPI */ |