1 /*@ S-nail - a mail user agent derived from Berkeley Mail.
2 *@ Implementation of SMTP GSS-API authentication according to RFC 4954.
3 *@ TODO GSS-API should also be joined into "a VFS".
5 * Copyright (c) 2014 - 2018 Steffen (Daode) Nurpmeso <steffen@sdaoden.eu>.
6 * SPDX-License-Identifier: BSD-4-Clause
9 /* Derived from `imap_gssapi.h', which is:
11 * Copyright (c) 2004 Gunnar Ritter.
12 * All rights reserved.
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution.
22 * 3. All advertising materials mentioning features or use of this software
23 * must display the following acknowledgement:
24 * This product includes software developed by Gunnar Ritter
25 * and his contributors.
26 * 4. Neither the name of Gunnar Ritter nor the names of his contributors
27 * may be used to endorse or promote products derived from this software
28 * without specific prior written permission.
30 * THIS SOFTWARE IS PROVIDED BY GUNNAR RITTER AND CONTRIBUTORS ``AS IS'' AND
31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED. IN NO EVENT SHALL GUNNAR RITTER OR CONTRIBUTORS BE LIABLE
34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
43 * Partially derived from sample code in:
45 * GSS-API Programming Guide
46 * Part No: 816-1331-11
47 * Sun Microsystems, Inc. 4150 Network Circle Santa Clara, CA 95054 U.S.A.
49 * (c) 2002 Sun Microsystems
52 * Copyright 1994 by OpenVision Technologies, Inc.
54 * Permission to use, copy, modify, distribute, and sell this software
55 * and its documentation for any purpose is hereby granted without fee,
56 * provided that the above copyright notice appears in all copies and
57 * that both that copyright notice and this permission notice appear in
58 * supporting documentation, and that the name of OpenVision not be used
59 * in advertising or publicity pertaining to distribution of the software
60 * without specific, written prior permission. OpenVision makes no
61 * representations about the suitability of this software for any
62 * purpose. It is provided "as is" without express or implied warranty.
64 * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
65 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
66 * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
67 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
68 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
69 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
70 * PERFORMANCE OF THIS SOFTWARE.
74 #ifndef GSSAPI_REG_INCLUDE
75 # include <gssapi/gssapi.h>
76 # ifdef GSSAPI_OLD_STYLE
77 # include <gssapi/gssapi_generic.h>
78 # define GSS_C_NT_HOSTBASED_SERVICE gss_nt_service_name
79 # define m_DEFINED_GCC_C_NT_HOSTBASED_SERVICE
85 static void _smtp_gssapi_error1(char const *s
, OM_uint32 code
, int typ
);
86 static void _smtp_gssapi_error(char const *s
, OM_uint32 maj_stat
,
90 _smtp_gssapi_error1(char const *s
, OM_uint32 code
, int typ
)
92 OM_uint32 maj_stat
, min_stat
;
93 gss_buffer_desc msg
= GSS_C_EMPTY_BUFFER
;
94 OM_uint32 msg_ctx
= 0;
98 maj_stat
= gss_display_status(&min_stat
, code
, typ
, GSS_C_NO_OID
,
100 if (maj_stat
== GSS_S_COMPLETE
) {
101 n_err(_("GSS error: %s / %.*s\n"),
102 s
, (int)msg
.length
, (char*)msg
.value
);
103 gss_release_buffer(&min_stat
, &msg
);
105 n_err(_("GSS error: %s / unknown\n"), s
);
113 _smtp_gssapi_error(char const *s
, OM_uint32 maj_stat
, OM_uint32 min_stat
)
116 _smtp_gssapi_error1(s
, maj_stat
, GSS_C_GSS_CODE
);
117 _smtp_gssapi_error1(s
, min_stat
, GSS_C_MECH_CODE
);
122 _smtp_gssapi(struct sock
*sp
, struct sendbundle
*sbp
, struct smtp_line
*slp
)
125 gss_buffer_desc send_tok
, recv_tok
;
126 gss_name_t target_name
;
127 gss_ctx_id_t gss_context
;
128 OM_uint32 maj_stat
, min_stat
, ret_flags
;
132 a_F_RECV_TOK
= 1u<<0,
133 a_F_SEND_TOK
= 1u<<1,
134 a_F_TARGET_NAME
= 1u<<2,
135 a_F_GSS_CONTEXT
= 1u<<3
143 if(INT_MAX
- 1 - 4 <= sbp
->sb_ccred
.cc_user
.l
)
146 send_tok
.value
= n_autorec_alloc(
147 (send_tok
.length
= sbp
->sb_url
.url_host
.l
+ 5) +1);
148 memcpy(send_tok
.value
, "smtp@", 5);
149 memcpy((char*)send_tok
.value
+ 5, sbp
->sb_url
.url_host
.s
,
150 sbp
->sb_url
.url_host
.l
+1);
151 maj_stat
= gss_import_name(&min_stat
, &send_tok
, GSS_C_NT_HOSTBASED_SERVICE
,
153 f
|= a_F_TARGET_NAME
;
154 if (maj_stat
!= GSS_S_COMPLETE
) {
155 _smtp_gssapi_error(savestrbuf(send_tok
.value
, send_tok
.length
),
160 gss_context
= GSS_C_NO_CONTEXT
;
161 maj_stat
= gss_init_sec_context(&min_stat
,
166 GSS_C_MUTUAL_FLAG
| GSS_C_SEQUENCE_FLAG
,
168 GSS_C_NO_CHANNEL_BINDINGS
,
174 f
|= a_F_SEND_TOK
| a_F_GSS_CONTEXT
;
175 if (maj_stat
!= GSS_S_COMPLETE
&& maj_stat
!= GSS_S_CONTINUE_NEEDED
) {
176 _smtp_gssapi_error("initializing GSS context", maj_stat
, min_stat
);
180 _OUT(NETLINE("AUTH GSSAPI"));
181 _ANSWER(3, FAL0
, FAL0
);
182 while (maj_stat
== GSS_S_CONTINUE_NEEDED
) {
183 /* Pass token obtained from first gss_init_sec_context() call */
184 if(b64_encode_buf(&out
, send_tok
.value
, send_tok
.length
,
185 B64_SALLOC
| B64_CRLF
) == NULL
)
187 gss_release_buffer(&min_stat
, &send_tok
);
190 _ANSWER(3, FAL0
, TRU1
);
195 if(!b64_decode(&out
, &in
))
197 recv_tok
.value
= out
.s
;
198 recv_tok
.length
= out
.l
;
199 maj_stat
= gss_init_sec_context(&min_stat
,
204 GSS_C_MUTUAL_FLAG
| GSS_C_SEQUENCE_FLAG
,
206 GSS_C_NO_CHANNEL_BINDINGS
,
214 if (maj_stat
!= GSS_S_COMPLETE
&& maj_stat
!= GSS_S_CONTINUE_NEEDED
) {
215 _smtp_gssapi_error("initializing context", maj_stat
, min_stat
);
220 gss_release_name(&min_stat
, &target_name
);
221 f
&= ~a_F_TARGET_NAME
;
223 /* Pass token obtained from second gss_init_sec_context() call */
224 if(b64_encode_buf(&out
, send_tok
.value
, send_tok
.length
,
225 B64_SALLOC
| B64_CRLF
) == NULL
)
229 gss_release_buffer(&min_stat
, &send_tok
);
232 _ANSWER(3, FAL0
, TRU1
);
236 if(!b64_decode(&out
, &in
)){
240 n_err(_("Invalid base64 encoding from GSSAPI server\n"));
243 recv_tok
.value
= out
.s
;
244 recv_tok
.length
= out
.l
;
245 maj_stat
= gss_unwrap(&min_stat
, gss_context
, &recv_tok
, &send_tok
,
248 gss_release_buffer(&min_stat
, &send_tok
);
249 /*f &= ~a_F_SEND_TOK;*/
250 if (maj_stat
!= GSS_S_COMPLETE
) {
251 _smtp_gssapi_error("unwrapping data", maj_stat
, min_stat
);
255 /* First octet: bit-mask with protection mechanisms (1 = no protection
257 * Second to fourth octet: maximum message size in network byte order.
258 * Fifth and following octets: user name string */
259 in
.s
= n_autorec_alloc((send_tok
.length
= 4 + sbp
->sb_ccred
.cc_user
.l
) +1);
260 memcpy(in
.s
+ 4, sbp
->sb_ccred
.cc_user
.s
, sbp
->sb_ccred
.cc_user
.l
+1);
263 in
.s
[2] = in
.s
[3] = (char)0xFF;
264 send_tok
.value
= in
.s
;
265 maj_stat
= gss_wrap(&min_stat
, gss_context
, 0, GSS_C_QOP_DEFAULT
, &send_tok
,
266 &conf_state
, &recv_tok
);
268 if (maj_stat
!= GSS_S_COMPLETE
) {
269 _smtp_gssapi_error("wrapping data", maj_stat
, min_stat
);
273 if(b64_encode_buf(&out
, recv_tok
.value
, recv_tok
.length
,
274 B64_SALLOC
| B64_CRLF
) == NULL
)
277 _ANSWER(2, FAL0
, FAL0
);
282 gss_release_buffer(&min_stat
, &recv_tok
);
284 gss_release_buffer(&min_stat
, &send_tok
);
285 if(f
& a_F_TARGET_NAME
)
286 gss_release_name(&min_stat
, &target_name
);
287 if(f
& a_F_GSS_CONTEXT
)
288 gss_delete_sec_context(&min_stat
, &gss_context
, GSS_C_NO_BUFFER
);
293 # ifdef m_DEFINED_GCC_C_NT_HOSTBASED_SERVICE
294 # undef GSS_C_NT_HOSTBASED_SERVICE
296 #endif /* HAVE_GSSAPI */