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

   1 /**
   2  * @file sip-sec-tls-dsk.c
   3  *
   4  * pidgin-sipe
   5  *
   6  * Copyright (C) 2011-2013 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 *domain,
  63                               SIPE_UNUSED_PARAMETER const gchar *username,
  64                               const gchar *password)
  65 {
  66         context_tls_dsk ctx = (context_tls_dsk) context;
  67
  68         return((ctx->state = sipe_tls_start((gpointer) password)) != NULL);
  69 }
  70
  71 static gboolean
  72 sip_sec_init_sec_context__tls_dsk(SipSecContext context,
  73                                   SipSecBuffer in_buff,
  74                                   SipSecBuffer *out_buff,
  75                                   SIPE_UNUSED_PARAMETER const gchar *service_name)
  76 {
  77         context_tls_dsk ctx = (context_tls_dsk) context;
  78         struct sipe_tls_state *state = ctx->state;
  79
  80         state->in_buffer = in_buff.value;
  81         state->in_length = in_buff.length;
  82
  83         if (sipe_tls_next(state)) {
  84                 if ((state->algorithm != SIPE_TLS_DIGEST_ALGORITHM_NONE) &&
  85                     state->client_key && state->server_key) {
  86                         /* Authentication is completed */
  87                         context->flags |= SIP_SEC_FLAG_COMMON_READY;
  88
  89                         /* copy key pair */
  90                         ctx->algorithm  = state->algorithm;
  91                         ctx->key_length = state->key_length;
  92                         ctx->client_key = g_memdup(state->client_key,
  93                                                    state->key_length);
  94                         ctx->server_key = g_memdup(state->server_key,
  95                                                    state->key_length);
  96
  97                         /* [MS-SIPAE] Section 3.2.2 Timers
  98                          *
  99                          * ... For an SA established using the TLS-DSK
 100                          * authentication protocol, the client MUST
 101                          * retrieve the expiration time of its certificate.
 102                          * The expiration timer value is the lesser of the
 103                          * interval to the certificate expiration and eight
 104                          * hours, ...
 105                          */
 106                         ctx->common.expires = sipe_tls_expires(state);
 107                         if (ctx->common.expires > (8 * 60 * 60))
 108                                 ctx->common.expires = 8 * 60 * 60;
 109
 110                         SIPE_DEBUG_INFO("sip_sec_init_sec_context__tls_dsk: handshake completed, algorithm %d, key length %" G_GSIZE_FORMAT ", expires %d",
 111                                         ctx->algorithm, ctx->key_length, ctx->common.expires);
 112
 113                         sipe_tls_free(state);
 114                         ctx->state = NULL;
 115                 } else {
 116                         out_buff->value  = state->out_buffer;
 117                         out_buff->length = state->out_length;
 118                         /* we take ownership of the buffer */
 119                         state->out_buffer = NULL;
 120                 }
 121         } else {
 122                 sipe_tls_free(state);
 123                 ctx->state = NULL;
 124         }
 125
 126         return(((context->flags & SIP_SEC_FLAG_COMMON_READY) ||
 127                 ctx->state));
 128 }
 129
 130 static gboolean
 131 sip_sec_make_signature__tls_dsk(SipSecContext context,
 132                                 const gchar *message,
 133                                 SipSecBuffer *signature)
 134 {
 135         context_tls_dsk ctx = (context_tls_dsk) context;
 136         gboolean result = FALSE;
 137
 138         switch (ctx->algorithm) {
 139         case SIPE_TLS_DIGEST_ALGORITHM_MD5:
 140                 signature->length = SIPE_DIGEST_HMAC_MD5_LENGTH;
 141                 signature->value  = g_malloc0(signature->length);
 142                 sipe_digest_hmac_md5(ctx->client_key, ctx->key_length,
 143                                      (guchar *) message, strlen(message),
 144                                      signature->value);
 145                 result = TRUE;
 146                 break;
 147
 148         case SIPE_TLS_DIGEST_ALGORITHM_SHA1:
 149                 signature->length = SIPE_DIGEST_HMAC_SHA1_LENGTH;
 150                 signature->value  = g_malloc0(signature->length);
 151                 sipe_digest_hmac_sha1(ctx->client_key, ctx->key_length,
 152                                       (guchar *) message, strlen(message),
 153                                       signature->value);
 154                 result = TRUE;
 155                 break;
 156
 157         default:
 158                 /* this should not happen */
 159                 break;
 160         }
 161
 162         return(result);
 163 }
 164
 165 static gboolean
 166 sip_sec_verify_signature__tls_dsk(SipSecContext context,
 167                                   const gchar *message,
 168                                   SipSecBuffer signature)
 169 {
 170         context_tls_dsk ctx = (context_tls_dsk) context;
 171         SipSecBuffer mac    = { 0, NULL };
 172         gboolean result     = FALSE;
 173
 174         switch (ctx->algorithm) {
 175         case SIPE_TLS_DIGEST_ALGORITHM_MD5:
 176                 mac.length = SIPE_DIGEST_HMAC_MD5_LENGTH;
 177                 mac.value  = g_malloc0(mac.length);
 178                 sipe_digest_hmac_md5(ctx->server_key, ctx->key_length,
 179                                      (guchar *) message, strlen(message),
 180                                      mac.value);
 181                 break;
 182
 183         case SIPE_TLS_DIGEST_ALGORITHM_SHA1:
 184                 mac.length = SIPE_DIGEST_HMAC_SHA1_LENGTH;
 185                 mac.value  = g_malloc0(mac.length);
 186                 sipe_digest_hmac_sha1(ctx->server_key, ctx->key_length,
 187                                       (guchar *) message, strlen(message),
 188                                       mac.value);
 189                 break;
 190
 191         default:
 192                 /* this should not happen */
 193                 break;
 194         }
 195
 196         if (mac.value) {
 197                 result = memcmp(signature.value, mac.value, mac.length) == 0;
 198                 g_free(mac.value);
 199         }
 200
 201         return(result);
 202 }
 203
 204 static void
 205 sip_sec_destroy_sec_context__tls_dsk(SipSecContext context)
 206 {
 207         context_tls_dsk ctx = (context_tls_dsk) context;
 208
 209         sipe_tls_free(ctx->state);
 210         g_free(ctx->client_key);
 211         g_free(ctx->server_key);
 212         g_free(ctx);
 213 }
 214
 215 static const gchar *
 216 sip_sec_context_name__tls_dsk(SIPE_UNUSED_PARAMETER SipSecContext context)
 217 {
 218         return("TLS-DSK");
 219 }
 220
 221 SipSecContext
 222 sip_sec_create_context__tls_dsk(SIPE_UNUSED_PARAMETER guint type)
 223 {
 224         context_tls_dsk context = g_malloc0(sizeof(struct _context_tls_dsk));
 225         if (!context) return(NULL);
 226
 227         context->common.acquire_cred_func     = sip_sec_acquire_cred__tls_dsk;
 228         context->common.init_context_func     = sip_sec_init_sec_context__tls_dsk;
 229         context->common.destroy_context_func  = sip_sec_destroy_sec_context__tls_dsk;
 230         context->common.make_signature_func   = sip_sec_make_signature__tls_dsk;
 231         context->common.verify_signature_func = sip_sec_verify_signature__tls_dsk;
 232         context->common.context_name_func     = sip_sec_context_name__tls_dsk;
 233
 234         return((SipSecContext) context);
 235 }
 236
 237 gboolean sip_sec_password__tls_dsk(void)
 238 {
 239 #if defined(HAVE_SSPI) || defined(HAVE_GSSAPI_GSSAPI_H)
 240         /*
 241          * TLS-DSK authenticates with a published client certificate. This
 242          * process uses Web Tickets and therefore goes through HTTP. If we
 243          * have authentication schemes compiled in which allow Single Sign-On
 244          * then we should allow password-less configurations.
 245          */
 246         return(FALSE);
 247 #else
 248         return(TRUE);
 249 #endif
 250 }
 251
 252 /*
 253   Local Variables:
 254   mode: c
 255   c-file-style: "bsd"
 256   indent-tabs-mode: t
 257   tab-width: 8
 258   End:
 259 */