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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 <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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/* 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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#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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gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
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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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gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET);
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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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new_packet_length += ret;
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/* FIXME: check characters before printing to screen so to not print
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terminal control characters */
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/* fprintf(stderr, "decrypted password is: "); */
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/* fwrite(*new_packet, 1, new_packet_length, stderr); */
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/* fprintf(stderr, "\n"); */
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/* Delete the GPGME plaintext data buffer */
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/* Delete the GPGME plaintext data buffer */
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gpgme_data_release(dh_plain);
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return new_packet_length;
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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, 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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(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));
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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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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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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;
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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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if(if_indextoname(if_index, interface) == NULL){
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perror("if_indextoname");
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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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fprintf(stderr, "Binding to interface %s\n", interface);
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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, "Bad address: %s\n", ip);
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to.sin6_port = htons(port); /* Spurious warning */
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to.sin6_scope_id = (uint32_t)if_index;
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fprintf(stderr, "Connection to: %s, port %d\n", ip, port);
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/* char addrstr[INET6_ADDRSTRLEN]; */
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/* if(inet_ntop(to.sin6_family, &(to.sin6_addr), addrstr, */
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/* sizeof(addrstr)) == NULL){ */
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/* perror("inet_ntop"); */
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/* fprintf(stderr, "Really connecting to: %s, port %d\n", */
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/* addrstr, ntohs(to.sin6_port)); */
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to.sin6_port = htons(port);
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to.sin6_scope_id = if_nametoindex("eth0");
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ret = connect(tcp_sd, (struct sockaddr *) &to, sizeof(to));
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gnutls_transport_set_ptr (es.session,
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(gnutls_transport_ptr_t) tcp_sd);
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fprintf(stderr, "Establishing TLS session with %s\n", ip);
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gnutls_transport_set_ptr (es.session, (gnutls_transport_ptr_t) tcp_sd);
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ret = gnutls_handshake (es.session);
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if (ret != GNUTLS_E_SUCCESS){
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fprintf(stderr, "\n*** Handshake failed ***\n");
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fprintf(stderr, "\n*** Handshake failed ***\n");
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//Retrieve OpenPGP packet that contains the wanted password
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fprintf(stderr, "Retrieving pgp encrypted password from %s\n",
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if (buffer_length + BUFFER_SIZE > buffer_capacity){
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buffer = realloc(buffer, buffer_capacity + BUFFER_SIZE);
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fprintf(stderr, "Unknown error while reading data from"
476
" encrypted session with mandos server\n");
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fprintf(stderr, "Unknown error while reading data from encrypted session with mandos server\n");
478
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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;
486
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if (buffer_length > 0){
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decrypted_buffer_size = pgp_packet_decrypt(buffer,
491
if (decrypted_buffer_size >= 0){
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while(written < (size_t) decrypted_buffer_size){
493
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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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);
539
432
const char *host_name,
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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,
544
437
AVAHI_GCC_UNUSED void* userdata) {
546
assert(r); /* Spurious warning */
548
/* Called whenever a service has been resolved successfully or
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case AVAHI_RESOLVER_FAILURE:
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fprintf(stderr, "(Resolver) Failed to resolve service '%s' of"
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" type '%s' in domain '%s': %s\n", name, type, domain,
556
avahi_strerror(avahi_server_errno(server)));
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case AVAHI_RESOLVER_FOUND:
561
char ip[AVAHI_ADDRESS_STR_MAX];
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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:
627
507
AvahiServerConfig config;
628
508
AvahiSServiceBrowser *sb = NULL;
631
int returncode = EXIT_SUCCESS;
632
const char *interface = "eth0";
633
unsigned int if_index;
634
char *connect_to = NULL;
637
static struct option long_options[] = {
638
{"debug", no_argument, (int *)&debug, 1},
639
{"connect", required_argument, 0, 'c'},
640
{"interface", required_argument, 0, 'i'},
643
int option_index = 0;
644
ret = getopt_long (argc, argv, "i:", long_options,
665
if_index = if_nametoindex(interface);
667
fprintf(stderr, "No such interface: \"%s\"\n", interface);
671
if(connect_to != NULL){
672
/* Connect directly, do not use Zeroconf */
673
/* (Mainly meant for debugging) */
674
char *address = strrchr(connect_to, ':');
676
fprintf(stderr, "No colon in address\n");
680
uint16_t port = (uint16_t) strtol(address+1, NULL, 10);
682
perror("Bad port number");
686
address = connect_to;
687
ret = start_mandos_communication(address, port, if_index);
696
avahi_set_log_function(empty_log);
512
avahi_set_log_function(empty_log);
699
514
/* Initialize the psuedo-RNG */
700
srand((unsigned int) time(NULL));
702
517
/* Allocate main loop object */
703
518
if (!(simple_poll = avahi_simple_poll_new())) {
704
519
fprintf(stderr, "Failed to create simple poll object.\n");
709
523
/* Do not publish any local records */
713
527
config.publish_workstation = 0;
714
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; */
716
535
/* Allocate a new server */
717
server = avahi_server_new(avahi_simple_poll_get(simple_poll),
718
&config, NULL, NULL, &error);
536
server = avahi_server_new(avahi_simple_poll_get(simple_poll), &config, NULL, NULL, &error);
720
538
/* Free the configuration data */
721
539
avahi_server_config_free(&config);
723
/* Check if creating the server object succeeded */
541
/* Check wether creating the server object succeeded */
725
fprintf(stderr, "Failed to create server: %s\n",
726
avahi_strerror(error));
727
returncode = EXIT_FAILURE;
543
fprintf(stderr, "Failed to create server: %s\n", avahi_strerror(error));
731
547
/* Create the service browser */
732
sb = avahi_s_service_browser_new(server, (AvahiIfIndex)if_index,
734
"_mandos._tcp", NULL, 0,
735
browse_callback, server);
737
fprintf(stderr, "Failed to create service browser: %s\n",
738
avahi_strerror(avahi_server_errno(server)));
739
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)));
743
553
/* Run the main loop */
746
fprintf(stderr, "Starting avahi loop search\n");
749
554
avahi_simple_poll_loop(simple_poll);
754
fprintf(stderr, "%s exiting\n", argv[0]);
757
560
/* Cleanup things */