imap_gssapi.c

   1 /*
   2  * Heirloom mailx - a mail user agent derived from Berkeley Mail.
   3  *
   4  * Copyright (c) 2000-2004 Gunnar Ritter, Freiburg i. Br., Germany.
   5  * Copyright (c) 2012 Steffen "Daode" Nurpmeso.
   6  */
   7 /*
   8  * Copyright (c) 2004
   9  *      Gunnar Ritter.  All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. All advertising materials mentioning features or use of this software
  20  *    must display the following acknowledgement:
  21  *      This product includes software developed by Gunnar Ritter
  22  *      and his contributors.
  23  * 4. Neither the name of Gunnar Ritter nor the names of his contributors
  24  *    may be used to endorse or promote products derived from this software
  25  *    without specific prior written permission.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY GUNNAR RITTER AND CONTRIBUTORS ``AS IS'' AND
  28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  30  * ARE DISCLAIMED.  IN NO EVENT SHALL GUNNAR RITTER OR CONTRIBUTORS BE LIABLE
  31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  37  * SUCH DAMAGE.
  38  */
  39
  40 /*
  41  * Partially derived from sample code in:
  42  *
  43  * GSS-API Programming Guide
  44  * Part No: 816-1331-11
  45  * Sun Microsystems, Inc. 4150 Network Circle Santa Clara, CA 95054 U.S.A.
  46  *
  47  * (c) 2002 Sun Microsystems
  48  */
  49 /*
  50  * Copyright 1994 by OpenVision Technologies, Inc.
  51  *
  52  * Permission to use, copy, modify, distribute, and sell this software
  53  * and its documentation for any purpose is hereby granted without fee,
  54  * provided that the above copyright notice appears in all copies and
  55  * that both that copyright notice and this permission notice appear in
  56  * supporting documentation, and that the name of OpenVision not be used
  57  * in advertising or publicity pertaining to distribution of the software
  58  * without specific, written prior permission. OpenVision makes no
  59  * representations about the suitability of this software for any
  60  * purpose.  It is provided "as is" without express or implied warranty.
  61  *
  62  * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  63  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  64  * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  65  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
  66  * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
  67  * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  68  * PERFORMANCE OF THIS SOFTWARE.
  69  */
  70
  71 #ifndef lint
  72 #ifdef  DOSCCS
  73 static char sccsid[] = "@(#)imap_gssapi.c       1.10 (gritter) 3/4/06";
  74 #endif
  75 #endif /* not lint */
  76
  77 /*
  78  * Implementation of IMAP GSSAPI authentication according to RFC 1731.
  79  */
  80
  81 #ifdef  USE_GSSAPI
  82
  83 #ifndef GSSAPI_REG_INCLUDE
  84 #include <gssapi/gssapi.h>
  85 #ifdef  GSSAPI_OLD_STYLE
  86 #include <gssapi/gssapi_generic.h>
  87 #define GSS_C_NT_HOSTBASED_SERVICE      gss_nt_service_name
  88 #endif  /* GSSAPI_OLD_STYLE */
  89 #else   /* GSSAPI_REG_INCLUDE */
  90 #include <gssapi.h>
  91 #endif  /* GSSAPI_REG_INCLUDE */
  92
  93 static void imap_gss_error1(const char *s, OM_uint32 code, int type);
  94 static void imap_gss_error(const char *s, OM_uint32 maj_stat,
  95                 OM_uint32 min_stat);
  96 static void
  97 imap_gss_error1(const char *s, OM_uint32 code, int type)
  98 {
  99         OM_uint32       maj_stat, min_stat;
 100         gss_buffer_desc msg = GSS_C_EMPTY_BUFFER;
 101         OM_uint32       msg_ctx = 0;
 102
 103         do {
 104                 maj_stat = gss_display_status(&min_stat, code, type,
 105                                 GSS_C_NO_OID, &msg_ctx, &msg);
 106                 if (maj_stat == GSS_S_COMPLETE) {
 107                         fprintf(stderr, "GSS error: %s / %s\n",
 108                                         s,
 109                                         (char *)msg.value);
 110                         if (msg.length != 0)
 111                                 gss_release_buffer(&min_stat, &msg);
 112                 } else {
 113                         fprintf(stderr, "GSS error: %s / unknown\n", s);
 114                         break;
 115                 }
 116         } while (msg_ctx);
 117 }
 118
 119 static void
 120 imap_gss_error(const char *s, OM_uint32 maj_stat, OM_uint32 min_stat)
 121 {
 122         imap_gss_error1(s, maj_stat, GSS_C_GSS_CODE);
 123         imap_gss_error1(s, min_stat, GSS_C_MECH_CODE);
 124 }
 125
 126 static enum okay
 127 imap_gss(struct mailbox *mp, char *user)
 128 {
 129         gss_buffer_desc send_tok, recv_tok, *token_ptr;
 130         gss_name_t      target_name;
 131         gss_ctx_id_t    gss_context;
 132         OM_uint32       maj_stat, min_stat, ret_flags;
 133         int     conf_state;
 134         struct str      in, out;
 135         FILE    *queuefp = NULL;
 136         char    *server, *cp;
 137         char    o[LINESIZE];
 138         enum okay       ok = STOP;
 139
 140         if (user == NULL && (user = getuser()) == NULL)
 141                 return STOP;
 142         server = salloc(strlen(mp->mb_imap_account));
 143         strcpy(server, mp->mb_imap_account);
 144         if (strncmp(server, "imap://", 7) == 0)
 145                 server += 7;
 146         else if (strncmp(server, "imaps://", 8) == 0)
 147                 server += 8;
 148         if ((cp = last_at_before_slash(server)) != NULL)
 149                 server = &cp[1];
 150         for (cp = server; *cp; cp++)
 151                 *cp = lowerconv(*cp&0377);
 152         send_tok.value = salloc(send_tok.length = strlen(server) + 6);
 153         snprintf(send_tok.value, send_tok.length, "imap@%s", server);
 154         maj_stat = gss_import_name(&min_stat, &send_tok,
 155                         GSS_C_NT_HOSTBASED_SERVICE, &target_name);
 156         if (maj_stat != GSS_S_COMPLETE) {
 157                 imap_gss_error(send_tok.value, maj_stat, min_stat);
 158                 return STOP;
 159         }
 160         token_ptr = GSS_C_NO_BUFFER;
 161         gss_context = GSS_C_NO_CONTEXT;
 162         maj_stat = gss_init_sec_context(&min_stat,
 163                         GSS_C_NO_CREDENTIAL,
 164                         &gss_context,
 165                         target_name,
 166                         GSS_C_NO_OID,
 167                         GSS_C_MUTUAL_FLAG|GSS_C_SEQUENCE_FLAG,
 168                         0,
 169                         GSS_C_NO_CHANNEL_BINDINGS,
 170                         token_ptr,
 171                         NULL,
 172                         &send_tok,
 173                         &ret_flags,
 174                         NULL);
 175         if (maj_stat != GSS_S_COMPLETE && maj_stat != GSS_S_CONTINUE_NEEDED) {
 176                 imap_gss_error("initializing GSS context", maj_stat, min_stat);
 177                 gss_release_name(&min_stat, &target_name);
 178                 return STOP;
 179         }
 180         snprintf(o, sizeof o, "%s AUTHENTICATE GSSAPI\r\n", tag(1));
 181         IMAP_OUT(o, 0, return STOP);
 182         /*
 183          * No response data expected.
 184          */
 185         imap_answer(mp, 1);
 186         if (response_type != RESPONSE_CONT)
 187                 return STOP;
 188         while (maj_stat == GSS_S_CONTINUE_NEEDED) {
 189                 /*
 190                  * Pass token obtained from first gss_init_sec_context() call.
 191                  */
 192                 cp = memtob64(send_tok.value, send_tok.length);
 193                 gss_release_buffer(&min_stat, &send_tok);
 194                 snprintf(o, sizeof o, "%s\r\n", cp);
 195                 free(cp);
 196                 IMAP_OUT(o, 0, return STOP);
 197                 imap_answer(mp, 1);
 198                 if (response_type != RESPONSE_CONT)
 199                         return STOP;
 200                 in.s = responded_text;
 201                 in.l = strlen(responded_text);
 202                 mime_fromb64(&in, &out, 0);
 203                 recv_tok.value = out.s;
 204                 recv_tok.length = out.l;
 205                 token_ptr = &recv_tok;
 206                 maj_stat = gss_init_sec_context(&min_stat,
 207                                 GSS_C_NO_CREDENTIAL,
 208                                 &gss_context,
 209                                 target_name,
 210                                 GSS_C_NO_OID,
 211                                 GSS_C_MUTUAL_FLAG|GSS_C_SEQUENCE_FLAG,
 212                                 0,
 213                                 GSS_C_NO_CHANNEL_BINDINGS,
 214                                 token_ptr,
 215                                 NULL,
 216                                 &send_tok,
 217                                 &ret_flags,
 218                                 NULL);
 219                 if (maj_stat != GSS_S_COMPLETE &&
 220                                 maj_stat != GSS_S_CONTINUE_NEEDED) {
 221                         imap_gss_error("initializing context",
 222                                         maj_stat, min_stat);
 223                         gss_release_name(&min_stat, &target_name);
 224                         return STOP;
 225                 }
 226                 free(out.s);
 227         }
 228         /*
 229          * Pass token obtained from second gss_init_sec_context() call.
 230          */
 231         gss_release_name(&min_stat, &target_name);
 232         cp = memtob64(send_tok.value, send_tok.length);
 233         gss_release_buffer(&min_stat, &send_tok);
 234         snprintf(o, sizeof o, "%s\r\n", cp);
 235         free(cp);
 236         IMAP_OUT(o, 0, return STOP);
 237         /*
 238          * First octet: bit-mask with protection mechanisms.
 239          * Second to fourth octet: maximum message size in network byte order.
 240          *
 241          * This code currently does not care about the values.
 242          */
 243         imap_answer(mp, 1);
 244         if (response_type != RESPONSE_CONT)
 245                 return STOP;
 246         in.s = responded_text;
 247         in.l = strlen(responded_text);
 248         mime_fromb64(&in, &out, 0);
 249         recv_tok.value = out.s;
 250         recv_tok.length = out.l;
 251         maj_stat = gss_unwrap(&min_stat, gss_context, &recv_tok,
 252                         &send_tok, &conf_state, NULL);
 253         if (maj_stat != GSS_S_COMPLETE) {
 254                 imap_gss_error("unwrapping data", maj_stat, min_stat);
 255                 return STOP;
 256         }
 257         free(out.s);
 258         /*
 259          * First octet: bit-mask with protection mechanisms (1 = no protection
 260          *      mechanism).
 261          * Second to fourth octet: maximum message size in network byte order.
 262          * Fifth and following octets: user name string.
 263          */
 264         o[0] = 1;
 265         o[1] = 0;
 266         o[2] = o[3] = (char)0377;
 267         snprintf(&o[4], sizeof o - 4, "%s", user);
 268         send_tok.value = o;
 269         send_tok.length = strlen(&o[4]) + 5;
 270         maj_stat = gss_wrap(&min_stat, gss_context, 0, GSS_C_QOP_DEFAULT,
 271                         &send_tok, &conf_state, &recv_tok);
 272         if (maj_stat != GSS_S_COMPLETE) {
 273                 imap_gss_error("wrapping data", maj_stat, min_stat);
 274                 return STOP;
 275         }
 276         cp = memtob64(recv_tok.value, recv_tok.length);
 277         snprintf(o, sizeof o, "%s\r\n", cp);
 278         free(cp);
 279         IMAP_OUT(o, MB_COMD, return STOP);
 280         while (mp->mb_active & MB_COMD)
 281                 ok = imap_answer(mp, 1);
 282         gss_delete_sec_context(&min_stat, &gss_context, &recv_tok);
 283         gss_release_buffer(&min_stat, &recv_tok);
 284         return ok;
 285 }
 286
 287 #endif  /* USE_GSSAPI */