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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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* Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson
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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 <mandos@fukt.bsnet.se>.
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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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/* Needed by GPGME, specifically gpgme_data_seek() */
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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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} encrypted_session;
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static ssize_t pgp_packet_decrypt (char *packet, size_t packet_size,
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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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static void debuggnutls(__attribute__((unused)) int level,
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void debuggnutls(int level, const char* string){
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fprintf(stderr, "%s", string);
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static int initgnutls(encrypted_session *es){
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int initgnutls(encrypted_session *es){
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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
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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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!= 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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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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safer_gnutls_strerror(ret));
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if ((ret = gnutls_priority_set_direct (es->session, "NORMAL", &err))
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!= 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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(es->session, GNUTLS_CRD_CERTIFICATE, es->cred))
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!= GNUTLS_E_SUCCESS) {
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safer_gnutls_strerror(ret));
341
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/* 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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static void empty_log(__attribute__((unused)) AvahiLogLevel level,
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__attribute__((unused)) const char *txt){}
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void empty_log(AvahiLogLevel level, const char *txt){}
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static int start_mandos_communication(const char *ip, uint16_t port,
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AvahiIfIndex 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;
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size_t buffer_length = 0;
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size_t buffer_capacity = 0;
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ssize_t decrypted_buffer_size;
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char interface[IF_NAMESIZE];
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fprintf(stderr, "Setting up a tcp connection to %s, port %d\n",
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tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);
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perror("socket");
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if(if_indextoname((unsigned int)if_index, interface) == NULL){
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perror("if_indextoname");
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fprintf(stderr, "Binding to interface %s\n", interface);
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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 */
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memset(&to,0,sizeof(to));
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to.sin6_family = AF_INET6;
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ret = inet_pton(AF_INET6, ip, &to.sin6_addr);
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ret = inet_pton(AF_INET6, ip, &ip_addr);
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perror("inet_pton");
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fprintf(stderr, "Unknown error while reading data from"
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" encrypted session with mandos server\n");
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fprintf(stderr, "Unknown error while reading data from encrypted session with mandos server\n");
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gnutls_bye (es.session, GNUTLS_SHUT_RDWR);
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buffer_length += (size_t) ret;
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buffer_length += ret;
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400
if (buffer_length > 0){
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decrypted_buffer_size = pgp_packet_decrypt(buffer,
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if (decrypted_buffer_size >= 0){
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while(written < (size_t) decrypted_buffer_size){
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ret = (int)fwrite (decrypted_buffer + written, 1,
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(size_t)decrypted_buffer_size - written,
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if(ret == 0 and ferror(stdout)){
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fprintf(stderr, "Error writing encrypted data: %s\n",
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written += (size_t)ret;
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if ((decrypted_buffer_size = gpg_packet_decrypt(buffer, buffer_length, &decrypted_buffer, CERT_ROOT)) == 0){
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fwrite (decrypted_buffer, 1, decrypted_buffer_size, stdout);
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405
free(decrypted_buffer);
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//shutdown procedure
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fprintf(stderr, "Closing TLS session\n");
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gnutls_bye (es.session, GNUTLS_SHUT_RDWR);
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const char *host_name,
548
433
const AvahiAddress *address,
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AVAHI_GCC_UNUSED AvahiStringList *txt,
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AVAHI_GCC_UNUSED AvahiLookupResultFlags flags,
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AvahiStringList *txt,
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AvahiLookupResultFlags flags,
552
437
AVAHI_GCC_UNUSED void* userdata) {
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assert(r); /* Spurious warning */
556
/* Called whenever a service has been resolved successfully or
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case AVAHI_RESOLVER_FAILURE:
562
fprintf(stderr, "(Resolver) Failed to resolve service '%s' of"
563
" type '%s' in domain '%s': %s\n", name, type, domain,
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avahi_strerror(avahi_server_errno(server)));
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case AVAHI_RESOLVER_FOUND:
569
char ip[AVAHI_ADDRESS_STR_MAX];
570
avahi_address_snprint(ip, sizeof(ip), address);
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fprintf(stderr, "Mandos server \"%s\" found on %s (%s) on"
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" port %d\n", name, host_name, ip, port);
575
int ret = start_mandos_communication(ip, port, 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);
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int ret = start_mandos_communcation(ip, port);
581
avahi_s_service_resolver_free(r);
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avahi_s_service_resolver_free(r);
584
462
static void browse_callback(
593
471
void* userdata) {
595
473
AvahiServer *s = userdata;
596
assert(b); /* Spurious warning */
598
/* Called whenever a new services becomes available on the LAN or
599
is removed from the LAN */
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/* Called whenever a new services becomes available on the LAN or is removed from the LAN */
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case AVAHI_BROWSER_FAILURE:
605
fprintf(stderr, "(Browser) %s\n",
606
avahi_strerror(avahi_server_errno(server)));
607
avahi_simple_poll_quit(simple_poll);
610
case AVAHI_BROWSER_NEW:
611
/* We ignore the returned resolver object. In the callback
612
function we free it. If the server is terminated before
613
the callback function is called the server will free
614
the resolver for us. */
616
if (!(avahi_s_service_resolver_new(s, interface, protocol, name,
618
AVAHI_PROTO_INET6, 0,
619
resolve_callback, s)))
620
fprintf(stderr, "Failed to resolve service '%s': %s\n", name,
621
avahi_strerror(avahi_server_errno(s)));
624
case AVAHI_BROWSER_REMOVE:
627
case AVAHI_BROWSER_ALL_FOR_NOW:
628
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:
633
/* Combines file name and path and returns the malloced new
634
string. some sane checks could/should be added */
635
static const char *combinepath(const char *first, const char *second){
636
size_t f_len = strlen(first);
637
size_t s_len = strlen(second);
638
char *tmp = malloc(f_len + s_len + 2);
643
memcpy(tmp, first, f_len);
647
memcpy(tmp + f_len + 1, second, s_len);
649
tmp[f_len + 1 + s_len] = '\0';
654
506
int main(AVAHI_GCC_UNUSED int argc, AVAHI_GCC_UNUSED char*argv[]) {
655
507
AvahiServerConfig config;
656
508
AvahiSServiceBrowser *sb = NULL;
659
int returncode = EXIT_SUCCESS;
660
const char *interface = "eth0";
661
struct ifreq network;
663
char *connect_to = NULL;
664
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
667
static struct option long_options[] = {
668
{"debug", no_argument, (int *)&debug, 1},
669
{"connect", required_argument, 0, 'C'},
670
{"interface", required_argument, 0, 'i'},
671
{"certdir", required_argument, 0, 'd'},
672
{"certkey", required_argument, 0, 'c'},
673
{"certfile", required_argument, 0, 'k'},
676
int option_index = 0;
677
ret = getopt_long (argc, argv, "i:", long_options,
707
certfile = combinepath(certdir, certfile);
708
if (certfile == NULL){
709
perror("combinepath");
710
returncode = EXIT_FAILURE;
714
certkey = combinepath(certdir, certkey);
715
if (certkey == NULL){
716
perror("combinepath");
717
returncode = EXIT_FAILURE;
721
if_index = (AvahiIfIndex) if_nametoindex(interface);
723
fprintf(stderr, "No such interface: \"%s\"\n", interface);
727
if(connect_to != NULL){
728
/* Connect directly, do not use Zeroconf */
729
/* (Mainly meant for debugging) */
730
char *address = strrchr(connect_to, ':');
732
fprintf(stderr, "No colon in address\n");
736
uint16_t port = (uint16_t) strtol(address+1, NULL, 10);
738
perror("Bad port number");
742
address = connect_to;
743
ret = start_mandos_communication(address, port, if_index);
751
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
754
returncode = EXIT_FAILURE;
757
strcpy(network.ifr_name, interface);
758
ret = ioctl(sd, SIOCGIFFLAGS, &network);
761
perror("ioctl SIOCGIFFLAGS");
762
returncode = EXIT_FAILURE;
765
if((network.ifr_flags & IFF_UP) == 0){
766
network.ifr_flags |= IFF_UP;
767
ret = ioctl(sd, SIOCSIFFLAGS, &network);
769
perror("ioctl SIOCSIFFLAGS");
770
returncode = EXIT_FAILURE;
777
avahi_set_log_function(empty_log);
512
avahi_set_log_function(empty_log);
780
514
/* Initialize the psuedo-RNG */
781
srand((unsigned int) time(NULL));
783
517
/* Allocate main loop object */
784
518
if (!(simple_poll = avahi_simple_poll_new())) {
785
519
fprintf(stderr, "Failed to create simple poll object.\n");
786
returncode = EXIT_FAILURE;
790
523
/* Do not publish any local records */
794
527
config.publish_workstation = 0;
795
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; */
797
535
/* Allocate a new server */
798
server = avahi_server_new(avahi_simple_poll_get(simple_poll),
799
&config, NULL, NULL, &error);
536
server = avahi_server_new(avahi_simple_poll_get(simple_poll), &config, NULL, NULL, &error);
801
538
/* Free the configuration data */
802
539
avahi_server_config_free(&config);
804
/* Check if creating the server object succeeded */
541
/* Check wether creating the server object succeeded */
806
fprintf(stderr, "Failed to create server: %s\n",
807
avahi_strerror(error));
808
returncode = EXIT_FAILURE;
543
fprintf(stderr, "Failed to create server: %s\n", avahi_strerror(error));
812
547
/* Create the service browser */
813
sb = avahi_s_service_browser_new(server, if_index,
815
"_mandos._tcp", NULL, 0,
816
browse_callback, server);
818
fprintf(stderr, "Failed to create service browser: %s\n",
819
avahi_strerror(avahi_server_errno(server)));
820
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)));
824
553
/* Run the main loop */
827
fprintf(stderr, "Starting avahi loop search\n");
830
554
avahi_simple_poll_loop(simple_poll);
835
fprintf(stderr, "%s exiting\n", argv[0]);
838
560
/* Cleanup things */