markus@openbsd.org | b8d9214 | 2018-07-09 21:37:55 +0000 | [diff] [blame] | 1 | /* $OpenBSD: gss-serv-krb5.c,v 1.9 2018/07/09 21:37:55 markus Exp $ */ |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 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 | |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 32 | #include <sys/types.h> |
| 33 | |
Damien Miller | ded319c | 2006-09-01 15:38:36 +1000 | [diff] [blame] | 34 | #include <stdarg.h> |
Damien Miller | b8fe89c | 2006-07-24 14:51:00 +1000 | [diff] [blame] | 35 | #include <string.h> |
| 36 | |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 37 | #include "xmalloc.h" |
markus@openbsd.org | b8d9214 | 2018-07-09 21:37:55 +0000 | [diff] [blame] | 38 | #include "sshkey.h" |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 39 | #include "hostfile.h" |
| 40 | #include "auth.h" |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 41 | #include "log.h" |
Darren Tucker | 450bc11 | 2014-07-19 06:23:18 +1000 | [diff] [blame] | 42 | #include "misc.h" |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 43 | #include "servconf.h" |
| 44 | |
| 45 | #include "ssh-gss.h" |
| 46 | |
| 47 | extern ServerOptions options; |
| 48 | |
Darren Tucker | 49aaf4a | 2003-08-26 11:58:16 +1000 | [diff] [blame] | 49 | #ifdef HEIMDAL |
Darren Tucker | 0d27ed1 | 2004-02-24 10:37:33 +1100 | [diff] [blame] | 50 | # include <krb5.h> |
Damien Miller | 63ddc89 | 2013-07-20 13:35:45 +1000 | [diff] [blame] | 51 | #endif |
| 52 | #ifdef HAVE_GSSAPI_KRB5_H |
| 53 | # include <gssapi_krb5.h> |
| 54 | #elif HAVE_GSSAPI_GSSAPI_KRB5_H |
| 55 | # include <gssapi/gssapi_krb5.h> |
Darren Tucker | 49aaf4a | 2003-08-26 11:58:16 +1000 | [diff] [blame] | 56 | #endif |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 57 | |
| 58 | static krb5_context krb_context = NULL; |
| 59 | |
| 60 | /* Initialise the krb5 library, for the stuff that GSSAPI won't do */ |
| 61 | |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 62 | static int |
Damien Miller | 10a445b | 2004-07-21 20:49:39 +1000 | [diff] [blame] | 63 | ssh_gssapi_krb5_init(void) |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 64 | { |
| 65 | krb5_error_code problem; |
| 66 | |
| 67 | if (krb_context != NULL) |
| 68 | return 1; |
| 69 | |
| 70 | problem = krb5_init_context(&krb_context); |
| 71 | if (problem) { |
| 72 | logit("Cannot initialize krb5 context"); |
| 73 | return 0; |
| 74 | } |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 75 | |
| 76 | return 1; |
| 77 | } |
| 78 | |
| 79 | /* Check if this user is OK to login. This only works with krb5 - other |
| 80 | * GSSAPI mechanisms will need their own. |
| 81 | * Returns true if the user is OK to log in, otherwise returns 0 |
| 82 | */ |
| 83 | |
| 84 | static int |
| 85 | ssh_gssapi_krb5_userok(ssh_gssapi_client *client, char *name) |
| 86 | { |
| 87 | krb5_principal princ; |
| 88 | int retval; |
Damien Miller | 63ddc89 | 2013-07-20 13:35:45 +1000 | [diff] [blame] | 89 | const char *errmsg; |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 90 | |
| 91 | if (ssh_gssapi_krb5_init() == 0) |
| 92 | return 0; |
| 93 | |
| 94 | if ((retval = krb5_parse_name(krb_context, client->exportedname.value, |
| 95 | &princ))) { |
Damien Miller | 63ddc89 | 2013-07-20 13:35:45 +1000 | [diff] [blame] | 96 | errmsg = krb5_get_error_message(krb_context, retval); |
| 97 | logit("krb5_parse_name(): %.100s", errmsg); |
| 98 | krb5_free_error_message(krb_context, errmsg); |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 99 | return 0; |
| 100 | } |
| 101 | if (krb5_kuserok(krb_context, princ, name)) { |
| 102 | retval = 1; |
| 103 | logit("Authorized to %s, krb5 principal %s (krb5_kuserok)", |
| 104 | name, (char *)client->displayname.value); |
| 105 | } else |
| 106 | retval = 0; |
| 107 | |
| 108 | krb5_free_principal(krb_context, princ); |
| 109 | return retval; |
| 110 | } |
| 111 | |
| 112 | |
| 113 | /* This writes out any forwarded credentials from the structure populated |
| 114 | * during userauth. Called after we have setuid to the user */ |
| 115 | |
| 116 | static void |
| 117 | ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client) |
| 118 | { |
| 119 | krb5_ccache ccache; |
| 120 | krb5_error_code problem; |
| 121 | krb5_principal princ; |
| 122 | OM_uint32 maj_status, min_status; |
Damien Miller | 34255b9 | 2004-02-17 20:33:52 +1100 | [diff] [blame] | 123 | int len; |
Damien Miller | 63ddc89 | 2013-07-20 13:35:45 +1000 | [diff] [blame] | 124 | const char *errmsg; |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 125 | |
| 126 | if (client->creds == NULL) { |
| 127 | debug("No credentials stored"); |
| 128 | return; |
| 129 | } |
| 130 | |
| 131 | if (ssh_gssapi_krb5_init() == 0) |
| 132 | return; |
| 133 | |
Darren Tucker | 49aaf4a | 2003-08-26 11:58:16 +1000 | [diff] [blame] | 134 | #ifdef HEIMDAL |
Darren Tucker | c74e70e | 2014-01-20 13:18:09 +1100 | [diff] [blame] | 135 | # ifdef HAVE_KRB5_CC_NEW_UNIQUE |
Damien Miller | 63ddc89 | 2013-07-20 13:35:45 +1000 | [diff] [blame] | 136 | if ((problem = krb5_cc_new_unique(krb_context, krb5_fcc_ops.prefix, |
| 137 | NULL, &ccache)) != 0) { |
| 138 | errmsg = krb5_get_error_message(krb_context, problem); |
| 139 | logit("krb5_cc_new_unique(): %.100s", errmsg); |
Darren Tucker | c74e70e | 2014-01-20 13:18:09 +1100 | [diff] [blame] | 140 | # else |
| 141 | if ((problem = krb5_cc_gen_new(krb_context, &krb5_fcc_ops, &ccache))) { |
| 142 | logit("krb5_cc_gen_new(): %.100s", |
| 143 | krb5_get_err_text(krb_context, problem)); |
| 144 | # endif |
Damien Miller | 63ddc89 | 2013-07-20 13:35:45 +1000 | [diff] [blame] | 145 | krb5_free_error_message(krb_context, errmsg); |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 146 | return; |
| 147 | } |
Darren Tucker | 49aaf4a | 2003-08-26 11:58:16 +1000 | [diff] [blame] | 148 | #else |
Darren Tucker | a916d14 | 2005-07-07 11:50:20 +1000 | [diff] [blame] | 149 | if ((problem = ssh_krb5_cc_gen(krb_context, &ccache))) { |
Damien Miller | 63ddc89 | 2013-07-20 13:35:45 +1000 | [diff] [blame] | 150 | errmsg = krb5_get_error_message(krb_context, problem); |
| 151 | logit("ssh_krb5_cc_gen(): %.100s", errmsg); |
| 152 | krb5_free_error_message(krb_context, errmsg); |
Darren Tucker | a916d14 | 2005-07-07 11:50:20 +1000 | [diff] [blame] | 153 | return; |
Darren Tucker | 49aaf4a | 2003-08-26 11:58:16 +1000 | [diff] [blame] | 154 | } |
| 155 | #endif /* #ifdef HEIMDAL */ |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 156 | |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 157 | if ((problem = krb5_parse_name(krb_context, |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 158 | client->exportedname.value, &princ))) { |
Damien Miller | 63ddc89 | 2013-07-20 13:35:45 +1000 | [diff] [blame] | 159 | errmsg = krb5_get_error_message(krb_context, problem); |
| 160 | logit("krb5_parse_name(): %.100s", errmsg); |
| 161 | krb5_free_error_message(krb_context, errmsg); |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 162 | return; |
| 163 | } |
| 164 | |
| 165 | if ((problem = krb5_cc_initialize(krb_context, ccache, princ))) { |
Damien Miller | 63ddc89 | 2013-07-20 13:35:45 +1000 | [diff] [blame] | 166 | errmsg = krb5_get_error_message(krb_context, problem); |
| 167 | logit("krb5_cc_initialize(): %.100s", errmsg); |
| 168 | krb5_free_error_message(krb_context, errmsg); |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 169 | krb5_free_principal(krb_context, princ); |
| 170 | krb5_cc_destroy(krb_context, ccache); |
| 171 | return; |
| 172 | } |
| 173 | |
| 174 | krb5_free_principal(krb_context, princ); |
| 175 | |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 176 | if ((maj_status = gss_krb5_copy_ccache(&min_status, |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 177 | client->creds, ccache))) { |
| 178 | logit("gss_krb5_copy_ccache() failed"); |
| 179 | krb5_cc_destroy(krb_context, ccache); |
| 180 | return; |
| 181 | } |
| 182 | |
| 183 | client->store.filename = xstrdup(krb5_cc_get_name(krb_context, ccache)); |
| 184 | client->store.envvar = "KRB5CCNAME"; |
Damien Miller | 34255b9 | 2004-02-17 20:33:52 +1100 | [diff] [blame] | 185 | len = strlen(client->store.filename) + 6; |
| 186 | client->store.envval = xmalloc(len); |
| 187 | snprintf(client->store.envval, len, "FILE:%s", client->store.filename); |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 188 | |
Darren Tucker | 49aaf4a | 2003-08-26 11:58:16 +1000 | [diff] [blame] | 189 | #ifdef USE_PAM |
| 190 | if (options.use_pam) |
Damien Miller | 34255b9 | 2004-02-17 20:33:52 +1100 | [diff] [blame] | 191 | do_pam_putenv(client->store.envvar, client->store.envval); |
Darren Tucker | 49aaf4a | 2003-08-26 11:58:16 +1000 | [diff] [blame] | 192 | #endif |
| 193 | |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 194 | krb5_cc_close(krb_context, ccache); |
| 195 | |
| 196 | return; |
| 197 | } |
| 198 | |
| 199 | ssh_gssapi_mech gssapi_kerberos_mech = { |
| 200 | "toWM5Slw5Ew8Mqkay+al2g==", |
| 201 | "Kerberos", |
| 202 | {9, "\x2A\x86\x48\x86\xF7\x12\x01\x02\x02"}, |
| 203 | NULL, |
| 204 | &ssh_gssapi_krb5_userok, |
| 205 | NULL, |
| 206 | &ssh_gssapi_krb5_storecreds |
| 207 | }; |
| 208 | |
| 209 | #endif /* KRB5 */ |
| 210 | |
| 211 | #endif /* GSSAPI */ |