src/core/sip-sec-tls-dsk.c

   1 /**
   2  * @file sip-sec-tls-dsk.c
   3  *
   4  * pidgin-sipe
   5  *
   6  * Copyright (C) 2011-2015 SIPE Project <http://sipe.sourceforge.net/>
   7  *
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  *
  23  *
  24  * Specification references:
  25  *
  26  *   - [MS-SIPAE]:    http://msdn.microsoft.com/en-us/library/cc431510.aspx
  27  *   - [MS-OCAUTHWS]: http://msdn.microsoft.com/en-us/library/ff595592.aspx
  28  *   - MS Tech-Ed Europe 2010 "UNC310: Microsoft Lync 2010 Technology Explained"
  29  *     http://ecn.channel9.msdn.com/o9/te/Europe/2010/pptx/unc310.pptx
  30  */
  31
  32 #ifdef HAVE_CONFIG_H
  33 #include "config.h"
  34 #endif
  35
  36 #include <string.h>
  37
  38 #include <glib.h>
  39
  40 #include "sipe-common.h"
  41 #include "sip-sec.h"
  42 #include "sip-sec-mech.h"
  43 #include "sip-sec-tls-dsk.h"
  44 #include "sipe-backend.h"
  45 #include "sipe-digest.h"
  46 #include "sipe-tls.h"
  47
  48 /* Security context for TLS-DSK */
  49 typedef struct _context_tls_dsk {
  50         struct sip_sec_context common;
  51         struct sipe_tls_state *state;
  52         enum sipe_tls_digest_algorithm algorithm;
  53         guchar *client_key;
  54         guchar *server_key;
  55         gsize key_length;
  56 } *context_tls_dsk;
  57
  58 /* sip-sec-mech.h API implementation for TLS-DSK */
  59
  60 static gboolean
  61 sip_sec_acquire_cred__tls_dsk(SipSecContext context,
  62                               SIPE_UNUSED_PARAMETER const gchar *username,
  63                               const gchar *password)
  64 {
  65         context_tls_dsk ctx = (context_tls_dsk) context;
  66
  67         return((ctx->state = sipe_tls_start((gpointer) password)) != NULL);
  68 }
  69
  70 static gboolean
  71 sip_sec_init_sec_context__tls_dsk(SipSecContext context,
  72                                   SipSecBuffer in_buff,
  73                                   SipSecBuffer *out_buff,
  74                                   SIPE_UNUSED_PARAMETER const gchar *service_name)
  75 {
  76         context_tls_dsk ctx = (context_tls_dsk) context;
  77         struct sipe_tls_state *state = ctx->state;
  78
  79         state->in_buffer = in_buff.value;
  80         state->in_length = in_buff.length;
  81
  82         if (sipe_tls_next(state)) {
  83                 if ((state->algorithm != SIPE_TLS_DIGEST_ALGORITHM_NONE) &&
  84                     state->client_key && state->server_key) {
  85                         /* Authentication is completed */
  86                         context->flags |= SIP_SEC_FLAG_COMMON_READY;
  87
  88                         /* copy key pair */
  89                         ctx->algorithm  = state->algorithm;
  90                         ctx->key_length = state->key_length;
  91                         ctx->client_key = g_memdup(state->client_key,
  92                                                    state->key_length);
  93                         ctx->server_key = g_memdup(state->server_key,
  94                                                    state->key_length);
  95
  96                         /* [MS-SIPAE] Section 3.2.2 Timers
  97                          *
  98                          * ... For an SA established using the TLS-DSK
  99                          * authentication protocol, the client MUST
 100                          * retrieve the expiration time of its certificate.
 101                          * The expiration timer value is the lesser of the
 102                          * interval to the certificate expiration and eight
 103                          * hours, ...
 104                          */
 105                         ctx->common.expires = sipe_tls_expires(state);
 106                         if (ctx->common.expires > (8 * 60 * 60))
 107                                 ctx->common.expires = 8 * 60 * 60;
 108
 109                         SIPE_DEBUG_INFO("sip_sec_init_sec_context__tls_dsk: handshake completed, algorithm %d, key length %" G_GSIZE_FORMAT ", expires %d",
 110                                         ctx->algorithm, ctx->key_length, ctx->common.expires);
 111
 112                         sipe_tls_free(state);
 113                         ctx->state = NULL;
 114                 } else {
 115                         out_buff->value  = state->out_buffer;
 116                         out_buff->length = state->out_length;
 117                         /* we take ownership of the buffer */
 118                         state->out_buffer = NULL;
 119                 }
 120         } else {
 121                 sipe_tls_free(state);
 122                 ctx->state = NULL;
 123         }
 124
 125         return(((context->flags & SIP_SEC_FLAG_COMMON_READY) ||
 126                 ctx->state));
 127 }
 128
 129 static gboolean
 130 sip_sec_make_signature__tls_dsk(SipSecContext context,
 131                                 const gchar *message,
 132                                 SipSecBuffer *signature)
 133 {
 134         context_tls_dsk ctx = (context_tls_dsk) context;
 135         gboolean result = FALSE;
 136
 137         switch (ctx->algorithm) {
 138         case SIPE_TLS_DIGEST_ALGORITHM_MD5:
 139                 signature->length = SIPE_DIGEST_HMAC_MD5_LENGTH;
 140                 signature->value  = g_malloc0(signature->length);
 141                 sipe_digest_hmac_md5(ctx->client_key, ctx->key_length,
 142                                      (guchar *) message, strlen(message),
 143                                      signature->value);
 144                 result = TRUE;
 145                 break;
 146
 147         case SIPE_TLS_DIGEST_ALGORITHM_SHA1:
 148                 signature->length = SIPE_DIGEST_HMAC_SHA1_LENGTH;
 149                 signature->value  = g_malloc0(signature->length);
 150                 sipe_digest_hmac_sha1(ctx->client_key, ctx->key_length,
 151                                       (guchar *) message, strlen(message),
 152                                       signature->value);
 153                 result = TRUE;
 154                 break;
 155
 156         default:
 157                 /* this should not happen */
 158                 break;
 159         }
 160
 161         return(result);
 162 }
 163
 164 static gboolean
 165 sip_sec_verify_signature__tls_dsk(SipSecContext context,
 166                                   const gchar *message,
 167                                   SipSecBuffer signature)
 168 {
 169         context_tls_dsk ctx = (context_tls_dsk) context;
 170         SipSecBuffer mac    = { 0, NULL };
 171         gboolean result     = FALSE;
 172
 173         switch (ctx->algorithm) {
 174         case SIPE_TLS_DIGEST_ALGORITHM_MD5:
 175                 mac.length = SIPE_DIGEST_HMAC_MD5_LENGTH;
 176                 mac.value  = g_malloc0(mac.length);
 177                 sipe_digest_hmac_md5(ctx->server_key, ctx->key_length,
 178                                      (guchar *) message, strlen(message),
 179                                      mac.value);
 180                 break;
 181
 182         case SIPE_TLS_DIGEST_ALGORITHM_SHA1:
 183                 mac.length = SIPE_DIGEST_HMAC_SHA1_LENGTH;
 184                 mac.value  = g_malloc0(mac.length);
 185                 sipe_digest_hmac_sha1(ctx->server_key, ctx->key_length,
 186                                       (guchar *) message, strlen(message),
 187                                       mac.value);
 188                 break;
 189
 190         default:
 191                 /* this should not happen */
 192                 break;
 193         }
 194
 195         if (mac.value) {
 196                 result = memcmp(signature.value, mac.value, mac.length) == 0;
 197                 g_free(mac.value);
 198         }
 199
 200         return(result);
 201 }
 202
 203 static void
 204 sip_sec_destroy_sec_context__tls_dsk(SipSecContext context)
 205 {
 206         context_tls_dsk ctx = (context_tls_dsk) context;
 207
 208         sipe_tls_free(ctx->state);
 209         g_free(ctx->client_key);
 210         g_free(ctx->server_key);
 211         g_free(ctx);
 212 }
 213
 214 static const gchar *
 215 sip_sec_context_name__tls_dsk(SIPE_UNUSED_PARAMETER SipSecContext context)
 216 {
 217         return("TLS-DSK");
 218 }
 219
 220 SipSecContext
 221 sip_sec_create_context__tls_dsk(SIPE_UNUSED_PARAMETER guint type)
 222 {
 223         context_tls_dsk context = g_malloc0(sizeof(struct _context_tls_dsk));
 224         if (!context) return(NULL);
 225
 226         context->common.acquire_cred_func     = sip_sec_acquire_cred__tls_dsk;
 227         context->common.init_context_func     = sip_sec_init_sec_context__tls_dsk;
 228         context->common.destroy_context_func  = sip_sec_destroy_sec_context__tls_dsk;
 229         context->common.make_signature_func   = sip_sec_make_signature__tls_dsk;
 230         context->common.verify_signature_func = sip_sec_verify_signature__tls_dsk;
 231         context->common.context_name_func     = sip_sec_context_name__tls_dsk;
 232
 233         return((SipSecContext) context);
 234 }
 235
 236 gboolean sip_sec_password__tls_dsk(void)
 237 {
 238 #if defined(HAVE_SSPI) || defined(HAVE_GSSAPI_GSSAPI_H)
 239         /*
 240          * TLS-DSK authenticates with a published client certificate. This
 241          * process uses Web Tickets and therefore goes through HTTP. If we
 242          * have authentication schemes compiled in which allow Single Sign-On
 243          * then we should allow password-less configurations.
 244          */
 245         return(FALSE);
 246 #else
 247         return(TRUE);
 248 #endif
 249 }
 250
 251 /*
 252   Local Variables:
 253   mode: c
 254   c-file-style: "bsd"
 255   indent-tabs-mode: t
 256   tab-width: 8
 257   End:
 258 */