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/* -*- coding: utf-8 -*- */
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* Mandos client - get and decrypt data from a Mandos server
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* This file demonstrates how to use Avahi's core API, this is
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* the embeddable mDNS stack for embedded applications.
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* This program is partly derived from an example program for an Avahi
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* service browser, downloaded from
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* <http://avahi.org/browser/examples/core-browse-services.c>. This
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* includes the following functions: "resolve_callback",
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* "browse_callback", and parts of "main".
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* Everything else is Copyright © 2007-2008 Teddy Hogeborn and Björn
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* This program is free software: you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, either version 3 of the
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* License, or (at your option) any later version.
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see
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* <http://www.gnu.org/licenses/>.
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* Contact the authors at <https://www.fukt.bsnet.se/~belorn/> and
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* <https://www.fukt.bsnet.se/~teddy/>.
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* End user applications should *not* use this API and should use
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* the D-Bus or C APIs, please see
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* client-browse-services.c and glib-integration.c
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* I repeat, you probably do *not* want to use this example.
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#define _FORTIFY_SOURCE 2
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This file is part of avahi.
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avahi is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as
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published by the Free Software Foundation; either version 2.1 of the
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License, or (at your option) any later version.
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avahi is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
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Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with avahi; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
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#define _LARGEFILE_SOURCE
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#define _FILE_OFFSET_BITS 64
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#include <avahi-common/error.h>
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//mandos client part
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#include <sys/types.h> /* socket(), inet_pton() */
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#include <sys/socket.h> /* socket(), struct sockaddr_in6,
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struct in6_addr, inet_pton() */
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#include <gnutls/gnutls.h> /* All GnuTLS stuff */
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#include <gnutls/openpgp.h> /* GnuTLS with openpgp stuff */
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#include <sys/types.h> /* socket(), setsockopt(), inet_pton() */
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#include <sys/socket.h> /* socket(), setsockopt(), struct sockaddr_in6, struct in6_addr, inet_pton() */
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#include <gnutls/gnutls.h> /* ALL GNUTLS STUFF */
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#include <gnutls/openpgp.h> /* gnutls with openpgp stuff */
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#include <unistd.h> /* close() */
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#include <netinet/in.h>
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} encrypted_session;
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ssize_t pgp_packet_decrypt (char *packet, size_t packet_size,
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char **new_packet, const char *homedir){
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ssize_t gpg_packet_decrypt (char *packet, size_t packet_size, char **new_packet, char *homedir){
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gpgme_data_t dh_crypto, dh_plain;
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ssize_t new_packet_capacity = 0;
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ssize_t new_packet_length = 0;
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size_t new_packet_capacity = 0;
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size_t new_packet_length = 0;
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gpgme_engine_info_t engine_info;
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fprintf(stderr, "Trying to decrypt OpenPGP packet\n");
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gpgme_check_version(NULL);
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rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
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if (rc != GPG_ERR_NO_ERROR){
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fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
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gpgme_strsource(rc), gpgme_strerror(rc));
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gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
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/* Set GPGME home directory */
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rc = gpgme_get_engine_info (&engine_info);
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/* Decrypt data from the FILE pointer to the plaintext data
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/* Decrypt data from the FILE pointer to the plaintext data buffer */
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rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);
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if (rc != GPG_ERR_NO_ERROR){
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fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
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gpgme_strsource(rc), gpgme_strerror(rc));
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fprintf(stderr, "Decryption of OpenPGP packet succeeded\n");
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gpgme_decrypt_result_t result;
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result = gpgme_op_decrypt_result(ctx);
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fprintf(stderr, "gpgme_op_decrypt_result failed\n");
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fprintf(stderr, "Unsupported algorithm: %s\n",
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result->unsupported_algorithm);
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fprintf(stderr, "Wrong key usage: %d\n",
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result->wrong_key_usage);
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if(result->file_name != NULL){
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fprintf(stderr, "File name: %s\n", result->file_name);
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gpgme_recipient_t recipient;
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recipient = result->recipients;
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while(recipient != NULL){
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fprintf(stderr, "Public key algorithm: %s\n",
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gpgme_pubkey_algo_name(recipient->pubkey_algo));
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fprintf(stderr, "Key ID: %s\n", recipient->keyid);
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fprintf(stderr, "Secret key available: %s\n",
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recipient->status == GPG_ERR_NO_SECKEY
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recipient = recipient->next;
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/* gpgme_decrypt_result_t result; */
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/* result = gpgme_op_decrypt_result(ctx); */
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/* fprintf(stderr, "Unsupported algorithm: %s\n", result->unsupported_algorithm); */
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/* fprintf(stderr, "Wrong key usage: %d\n", result->wrong_key_usage); */
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/* if(result->file_name != NULL){ */
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/* fprintf(stderr, "File name: %s\n", result->file_name); */
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/* gpgme_recipient_t recipient; */
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/* recipient = result->recipients; */
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/* while(recipient != NULL){ */
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/* fprintf(stderr, "Public key algorithm: %s\n", */
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/* gpgme_pubkey_algo_name(recipient->pubkey_algo)); */
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/* fprintf(stderr, "Key ID: %s\n", recipient->keyid); */
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/* fprintf(stderr, "Secret key available: %s\n", */
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/* recipient->status == GPG_ERR_NO_SECKEY ? "No" : "Yes"); */
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/* recipient = recipient->next; */
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/* Delete the GPGME FILE pointer cryptotext data buffer */
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gpgme_data_release(dh_crypto);
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/* Seek back to the beginning of the GPGME plaintext data buffer */
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if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){
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perror("pgpme_data_seek");
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gpgme_data_seek(dh_plain, 0, SEEK_SET);
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if (new_packet_length + BUFFER_SIZE > new_packet_capacity){
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*new_packet = realloc(*new_packet,
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(unsigned int)new_packet_capacity
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*new_packet = realloc(*new_packet, new_packet_capacity + BUFFER_SIZE);
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if (*new_packet == NULL){
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perror("realloc");
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fprintf(stderr, "Initializing GnuTLS\n");
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if ((ret = gnutls_global_init ())
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!= GNUTLS_E_SUCCESS) {
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fprintf (stderr, "global_init: %s\n", safer_gnutls_strerror(ret));
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gnutls_global_set_log_level(11);
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gnutls_global_set_log_function(debuggnutls);
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/* Uncomment to enable full debuggin on the gnutls library */
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/* gnutls_global_set_log_level(11); */
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/* gnutls_global_set_log_function(debuggnutls); */
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/* openpgp credentials */
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if ((ret = gnutls_certificate_allocate_credentials (&es->cred))
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!= GNUTLS_E_SUCCESS) {
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fprintf (stderr, "memory error: %s\n",
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safer_gnutls_strerror(ret));
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fprintf (stderr, "memory error: %s\n", safer_gnutls_strerror(ret));
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fprintf(stderr, "Attempting to use OpenPGP certificate %s"
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" and keyfile %s as GnuTLS credentials\n", certfile,
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ret = gnutls_certificate_set_openpgp_key_file
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(es->cred, certfile, certkey, GNUTLS_OPENPGP_FMT_BASE64);
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(es->cred, CERTFILE, KEYFILE, GNUTLS_OPENPGP_FMT_BASE64);
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if (ret != GNUTLS_E_SUCCESS) {
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(stderr, "Error[%d] while reading the OpenPGP key pair ('%s',"
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ret, certfile, certkey);
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(stderr, "Error[%d] while reading the OpenPGP key pair ('%s', '%s')\n",
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ret, CERTFILE, KEYFILE);
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fprintf(stdout, "The Error is: %s\n",
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safer_gnutls_strerror(ret));
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//GnuTLS server initialization
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//Gnutls server initialization
303
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if ((ret = gnutls_dh_params_init (&es->dh_params))
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!= GNUTLS_E_SUCCESS) {
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fprintf (stderr, "Error in dh parameter initialization: %s\n",
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safer_gnutls_strerror(ret));
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if ((ret = gnutls_dh_params_generate2 (es->dh_params, DH_BITS))
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255
!= GNUTLS_E_SUCCESS) {
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fprintf (stderr, "Error in prime generation: %s\n",
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safer_gnutls_strerror(ret));
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261
gnutls_certificate_set_dh_params (es->cred, es->dh_params);
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// GnuTLS session creation
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// Gnutls session creation
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if ((ret = gnutls_init (&es->session, GNUTLS_SERVER))
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!= GNUTLS_E_SUCCESS){
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fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
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fprintf(stderr, "Error in gnutls session initialization: %s\n",
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267
safer_gnutls_strerror(ret));
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if ((ret = gnutls_priority_set_direct (es->session, "NORMAL", &err))
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271
!= GNUTLS_E_SUCCESS) {
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fprintf(stderr, "Syntax error at: %s\n", err);
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fprintf(stderr, "GnuTLS error: %s\n",
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fprintf(stderr, "Gnutls error: %s\n",
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safer_gnutls_strerror(ret));
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if ((ret = gnutls_credentials_set
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279
(es->session, GNUTLS_CRD_CERTIFICATE, es->cred))
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280
!= GNUTLS_E_SUCCESS) {
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282
safer_gnutls_strerror(ret));
342
286
/* ignore client certificate if any. */
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gnutls_certificate_server_set_request (es->session,
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gnutls_certificate_server_set_request (es->session, GNUTLS_CERT_IGNORE);
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gnutls_dh_set_prime_bits (es->session, DH_BITS);
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void empty_log(__attribute__((unused)) AvahiLogLevel level,
352
__attribute__((unused)) const char *txt){}
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void empty_log(AvahiLogLevel level, const char *txt){}
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int start_mandos_communication(const char *ip, uint16_t port,
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unsigned int if_index){
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int start_mandos_communcation(char *ip, uint16_t port){
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struct sockaddr_in6 to;
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struct in6_addr ip_addr;
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encrypted_session es;
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char *buffer = NULL;
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char *decrypted_buffer;
361
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size_t buffer_length = 0;
362
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size_t buffer_capacity = 0;
363
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ssize_t decrypted_buffer_size;
366
char interface[IF_NAMESIZE];
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fprintf(stderr, "Setting up a tcp connection to %s\n", ip);
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tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);
374
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perror("socket");
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if(if_indextoname(if_index, interface) == NULL){
381
perror("if_indextoname");
386
fprintf(stderr, "Binding to interface %s\n", interface);
315
ret = setsockopt(tcp_sd, SOL_SOCKET, SO_BINDTODEVICE, "eth0", 5);
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perror("setsockopt bindtodevice");
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memset(&to,0,sizeof(to)); /* Spurious warning */
321
memset(&to,0,sizeof(to));
390
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to.sin6_family = AF_INET6;
391
ret = inet_pton(AF_INET6, ip, &to.sin6_addr);
323
ret = inet_pton(AF_INET6, ip, &ip_addr);
393
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perror("inet_pton");
420
gnutls_transport_set_ptr (es.session,
421
(gnutls_transport_ptr_t) tcp_sd);
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fprintf(stderr, "Establishing TLS session with %s\n", ip);
348
gnutls_transport_set_ptr (es.session, (gnutls_transport_ptr_t) tcp_sd);
427
350
ret = gnutls_handshake (es.session);
429
352
if (ret != GNUTLS_E_SUCCESS){
431
fprintf(stderr, "\n*** Handshake failed ***\n");
353
fprintf(stderr, "\n*** Handshake failed ***\n");
438
//Retrieve OpenPGP packet that contains the wanted password
441
fprintf(stderr, "Retrieving pgp encrypted password from %s\n",
446
361
if (buffer_length + BUFFER_SIZE > buffer_capacity){
447
362
buffer = realloc(buffer, buffer_capacity + BUFFER_SIZE);
475
fprintf(stderr, "Unknown error while reading data from"
476
" encrypted session with mandos server\n");
390
fprintf(stderr, "Unknown error while reading data from encrypted session with mandos server\n");
478
392
gnutls_bye (es.session, GNUTLS_SHUT_RDWR);
482
buffer_length += (size_t) ret;
396
buffer_length += ret;
486
400
if (buffer_length > 0){
487
decrypted_buffer_size = pgp_packet_decrypt(buffer,
491
if (decrypted_buffer_size >= 0){
492
while(written < (size_t)decrypted_buffer_size){
493
ret = (int)fwrite (decrypted_buffer + written, 1,
494
(size_t)decrypted_buffer_size - written,
496
if(ret == 0 and ferror(stdout)){
498
fprintf(stderr, "Error writing encrypted data: %s\n",
504
written += (size_t)ret;
401
if ((decrypted_buffer_size = gpg_packet_decrypt(buffer, buffer_length, &decrypted_buffer, CERT_ROOT)) == 0){
404
fwrite (decrypted_buffer, 1, decrypted_buffer_size, stdout);
506
405
free(decrypted_buffer);
512
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//shutdown procedure
515
fprintf(stderr, "Closing TLS session\n");
519
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gnutls_bye (es.session, GNUTLS_SHUT_RDWR);
539
432
const char *host_name,
540
433
const AvahiAddress *address,
542
AVAHI_GCC_UNUSED AvahiStringList *txt,
543
AVAHI_GCC_UNUSED AvahiLookupResultFlags flags,
435
AvahiStringList *txt,
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AvahiLookupResultFlags flags,
544
437
AVAHI_GCC_UNUSED void* userdata) {
546
assert(r); /* Spurious warning */
548
/* Called whenever a service has been resolved successfully or
553
case AVAHI_RESOLVER_FAILURE:
554
fprintf(stderr, "(Resolver) Failed to resolve service '%s' of"
555
" type '%s' in domain '%s': %s\n", name, type, domain,
556
avahi_strerror(avahi_server_errno(server)));
559
case AVAHI_RESOLVER_FOUND:
561
char ip[AVAHI_ADDRESS_STR_MAX];
562
avahi_address_snprint(ip, sizeof(ip), address);
564
fprintf(stderr, "Mandos server \"%s\" found on %s (%s) on"
565
" port %d\n", name, host_name, ip, port);
567
int ret = start_mandos_communication(ip, port,
568
(unsigned int) interface);
441
/* Called whenever a service has been resolved successfully or timed out */
444
case AVAHI_RESOLVER_FAILURE:
445
fprintf(stderr, "(Resolver) Failed to resolve service '%s' of type '%s' in domain '%s': %s\n", name, type, domain, avahi_strerror(avahi_server_errno(server)));
448
case AVAHI_RESOLVER_FOUND: {
449
char ip[AVAHI_ADDRESS_STR_MAX];
450
avahi_address_snprint(ip, sizeof(ip), address);
451
int ret = start_mandos_communcation(ip, port);
574
avahi_s_service_resolver_free(r);
459
avahi_s_service_resolver_free(r);
577
462
static void browse_callback(
586
471
void* userdata) {
588
473
AvahiServer *s = userdata;
589
assert(b); /* Spurious warning */
591
/* Called whenever a new services becomes available on the LAN or
592
is removed from the LAN */
476
/* Called whenever a new services becomes available on the LAN or is removed from the LAN */
596
case AVAHI_BROWSER_FAILURE:
598
fprintf(stderr, "(Browser) %s\n",
599
avahi_strerror(avahi_server_errno(server)));
600
avahi_simple_poll_quit(simple_poll);
603
case AVAHI_BROWSER_NEW:
604
/* We ignore the returned resolver object. In the callback
605
function we free it. If the server is terminated before
606
the callback function is called the server will free
607
the resolver for us. */
609
if (!(avahi_s_service_resolver_new(s, interface, protocol, name,
611
AVAHI_PROTO_INET6, 0,
612
resolve_callback, s)))
613
fprintf(stderr, "Failed to resolve service '%s': %s\n", name,
614
avahi_strerror(avahi_server_errno(s)));
617
case AVAHI_BROWSER_REMOVE:
620
case AVAHI_BROWSER_ALL_FOR_NOW:
621
case AVAHI_BROWSER_CACHE_EXHAUSTED:
480
case AVAHI_BROWSER_FAILURE:
482
fprintf(stderr, "(Browser) %s\n", avahi_strerror(avahi_server_errno(server)));
483
avahi_simple_poll_quit(simple_poll);
486
case AVAHI_BROWSER_NEW:
487
/* We ignore the returned resolver object. In the callback
488
function we free it. If the server is terminated before
489
the callback function is called the server will free
490
the resolver for us. */
492
if (!(avahi_s_service_resolver_new(s, interface, protocol, name, type, domain, AVAHI_PROTO_INET6, 0, resolve_callback, s)))
493
fprintf(stderr, "Failed to resolve service '%s': %s\n", name, avahi_strerror(avahi_server_errno(s)));
497
case AVAHI_BROWSER_REMOVE:
500
case AVAHI_BROWSER_ALL_FOR_NOW:
501
case AVAHI_BROWSER_CACHE_EXHAUSTED:
626
/* combinds file name and path and returns the malloced new string. som sane checks could/should be added */
627
const char *combinepath(const char *first, const char *second){
629
tmp = malloc(strlen(first) + strlen(second) + 2);
635
if (first[0] != '\0' and first[strlen(first) - 1] != '/'){
643
506
int main(AVAHI_GCC_UNUSED int argc, AVAHI_GCC_UNUSED char*argv[]) {
644
507
AvahiServerConfig config;
645
508
AvahiSServiceBrowser *sb = NULL;
648
int returncode = EXIT_SUCCESS;
649
const char *interface = "eth0";
650
struct ifreq network;
654
static struct option long_options[] = {
655
{"debug", no_argument, (int *)&debug, 1},
656
{"interface", required_argument, 0, 'i'},
657
{"certdir", required_argument, 0, 'd'},
658
{"certkey", required_argument, 0, 'c'},
659
{"certfile", required_argument, 0, 'k'},
662
int option_index = 0;
663
ret = getopt_long (argc, argv, "i:", long_options,
690
certfile = combinepath(certdir, certfile);
691
if (certfile == NULL){
692
returncode = EXIT_FAILURE;
696
certkey = combinepath(certdir, certkey);
697
if (certkey == NULL){
698
returncode = EXIT_FAILURE;
702
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
705
returncode = EXIT_FAILURE;
708
strcpy(network.ifr_name, interface);
709
ret = ioctl(sd, SIOCGIFFLAGS, &network);
712
perror("ioctl SIOCGIFFLAGS");
713
returncode = EXIT_FAILURE;
716
if((network.ifr_flags & IFF_UP) == 0){
717
network.ifr_flags |= IFF_UP;
718
ret = ioctl(sd, SIOCSIFFLAGS, &network);
720
perror("ioctl SIOCSIFFLAGS");
721
returncode = EXIT_FAILURE;
728
avahi_set_log_function(empty_log);
512
avahi_set_log_function(empty_log);
731
514
/* Initialize the psuedo-RNG */
732
srand((unsigned int) time(NULL));
734
517
/* Allocate main loop object */
735
518
if (!(simple_poll = avahi_simple_poll_new())) {
736
519
fprintf(stderr, "Failed to create simple poll object.\n");
737
returncode = EXIT_FAILURE;
741
523
/* Do not publish any local records */
745
527
config.publish_workstation = 0;
746
528
config.publish_domain = 0;
530
/* /\* Set a unicast DNS server for wide area DNS-SD *\/ */
531
/* avahi_address_parse("193.11.177.11", AVAHI_PROTO_UNSPEC, &config.wide_area_servers[0]); */
532
/* config.n_wide_area_servers = 1; */
533
/* config.enable_wide_area = 1; */
748
535
/* Allocate a new server */
749
server = avahi_server_new(avahi_simple_poll_get(simple_poll),
750
&config, NULL, NULL, &error);
536
server = avahi_server_new(avahi_simple_poll_get(simple_poll), &config, NULL, NULL, &error);
752
538
/* Free the configuration data */
753
539
avahi_server_config_free(&config);
755
/* Check if creating the server object succeeded */
541
/* Check wether creating the server object succeeded */
757
fprintf(stderr, "Failed to create server: %s\n",
758
avahi_strerror(error));
759
returncode = EXIT_FAILURE;
543
fprintf(stderr, "Failed to create server: %s\n", avahi_strerror(error));
763
547
/* Create the service browser */
764
sb = avahi_s_service_browser_new(server,
766
if_nametoindex(interface),
768
"_mandos._tcp", NULL, 0,
769
browse_callback, server);
771
fprintf(stderr, "Failed to create service browser: %s\n",
772
avahi_strerror(avahi_server_errno(server)));
773
returncode = EXIT_FAILURE;
548
if (!(sb = avahi_s_service_browser_new(server, if_nametoindex("eth0"), AVAHI_PROTO_INET6, "_mandos._tcp", NULL, 0, browse_callback, server))) {
549
fprintf(stderr, "Failed to create service browser: %s\n", avahi_strerror(avahi_server_errno(server)));
777
553
/* Run the main loop */
780
fprintf(stderr, "Starting avahi loop search\n");
783
554
avahi_simple_poll_loop(simple_poll);
788
fprintf(stderr, "%s exiting\n", argv[0]);
791
560
/* Cleanup things */