/mandos/release : revision 237.2.29

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/* -*- coding: utf-8 -*- */

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/*

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* Mandos client - get and decrypt data from a Mandos server

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* Mandos-client - get and decrypt data from a Mandos server

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*

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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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* "browse_callback", and parts of "main".

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*

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* Everything else is

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*

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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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#define _LARGEFILE_SOURCE

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#define _FILE_OFFSET_BITS 64

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35

#define _GNU_SOURCE /* TEMP_FAILURE_RETRY() */

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#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */

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#include <stdio.h> /* fprintf(), stderr, fwrite(), stdout,

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ferror() */

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#include <stdio.h> /* fprintf(), stderr, fwrite(),

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stdout, ferror(), sscanf */

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#include <stdint.h> /* uint16_t, uint32_t */

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#include <stddef.h> /* NULL, size_t, ssize_t */

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#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,

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srand() */

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#include <stdbool.h> /* bool, true */

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#include <string.h> /* memset(), strcmp(), strlen(),

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strerror(), memcpy(), strcpy() */

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strerror(), asprintf(), strcpy() */

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#include <sys/ioctl.h> /* ioctl */

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#include <net/if.h> /* ifreq, SIOCGIFFLAGS, SIOCSIFFLAGS,

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IFF_UP */

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#include <sys/types.h> /* socket(), inet_pton(), sockaddr,

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sockaddr_in6, PF_INET6,

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SOCK_STREAM, INET6_ADDRSTRLEN,

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uid_t, gid_t */

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#include <inttypes.h> /* PRIu16 */

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uid_t, gid_t, open(), opendir(),

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DIR */

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#include <sys/stat.h> /* open() */

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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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connect() */

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#include <fcntl.h> /* open() */

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#include <dirent.h> /* opendir(), struct dirent, readdir()

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*/

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#include <inttypes.h> /* PRIu16, SCNu16 */

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#include <assert.h> /* assert() */

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62

#include <errno.h> /* perror(), errno */

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#include <time.h> /* time() */

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#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,

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SIOCSIFFLAGS, if_indextoname(),

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if_nametoindex(), IF_NAMESIZE */

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#include <netinet/in.h>

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#include <unistd.h> /* close(), SEEK_SET, off_t, write(),

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getuid(), getgid(), setuid(),

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setgid() */

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#include <netinet/in.h>

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#include <arpa/inet.h> /* inet_pton(), htons */

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#include <iso646.h> /* not, and */

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#include <iso646.h> /* not, and, or */

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#include <argp.h> /* struct argp_option, error_t, struct

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argp_state, struct argp,

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argp_parse(), ARGP_KEY_ARG,

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#include <avahi-common/error.h>

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/* GnuTLS */

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#include <gnutls/gnutls.h> /* All GnuTLS types, constants and functions

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#include <gnutls/gnutls.h> /* All GnuTLS types, constants and

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functions:

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gnutls_*

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init_gnutls_session(),

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GNUTLS_* */

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#include <gnutls/openpgp.h> /* gnutls_certificate_set_openpgp_key_file(),

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#include <gnutls/openpgp.h>

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/* gnutls_certificate_set_openpgp_key_file(),

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GNUTLS_OPENPGP_FMT_BASE64 */

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/* GPGME */

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#include <gpgme.h> /* All GPGME types, constants and functions

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#include <gpgme.h> /* All GPGME types, constants and

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functions:

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gpgme_*

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GPGME_PROTOCOL_OpenPGP,

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GPG_ERR_NO_* */

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#define BUFFER_SIZE 256

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#define PATHDIR "/conf/conf.d/mandos"

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#define SECKEY "seckey.txt"

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#define PUBKEY "pubkey.txt"

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112

bool debug = false;

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static const char *keydir = "/conf/conf.d/mandos";

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static const char mandos_protocol_version[] = "1";

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const char *argp_program_version = "password-request 1.0";

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const char *argp_program_version = "mandos-client " VERSION;

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const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";

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/* Used for passing in values through the Avahi callback functions */

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unsigned int dh_bits;

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gnutls_dh_params_t dh_params;

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const char *priority;

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gpgme_ctx_t ctx;

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} mandos_context;

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127

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/*

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132

*/

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size_t adjustbuffer(char **buffer, size_t buffer_length,

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size_t buffer_capacity){

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if (buffer_length + BUFFER_SIZE > buffer_capacity){

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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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if (buffer == NULL){

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if(buffer == NULL){

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return 0;

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}

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buffer_capacity += BUFFER_SIZE;

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}

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/*

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* Decrypt OpenPGP data using keyrings in HOMEDIR.

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* Returns -1 on error

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* Initialize GPGME.

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*/

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static ssize_t pgp_packet_decrypt (const char *cryptotext,

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size_t crypto_size,

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char **plaintext,

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const char *homedir){

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gpgme_data_t dh_crypto, dh_plain;

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gpgme_ctx_t ctx;

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static bool init_gpgme(mandos_context *mc, const char *seckey,

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const char *pubkey, const char *tempdir){

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int ret;

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gpgme_error_t rc;

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ssize_t ret;

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size_t plaintext_capacity = 0;

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ssize_t plaintext_length = 0;

148

152

gpgme_engine_info_t engine_info;

149

153

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if (debug){

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fprintf(stderr, "Trying to decrypt OpenPGP data\n");

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/*

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* Helper function to insert pub and seckey to the enigne keyring.

157

*/

158

bool import_key(const char *filename){

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int fd;

160

gpgme_data_t pgp_data;

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fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));

163

if(fd == -1){

164

perror("open");

165

return false;

166

}

167

168

rc = gpgme_data_new_from_fd(&pgp_data, fd);

169

if(rc != GPG_ERR_NO_ERROR){

170

fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",

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gpgme_strsource(rc), gpgme_strerror(rc));

172

return false;

173

}

174

175

rc = gpgme_op_import(mc->ctx, pgp_data);

176

if(rc != GPG_ERR_NO_ERROR){

177

fprintf(stderr, "bad gpgme_op_import: %s: %s\n",

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gpgme_strsource(rc), gpgme_strerror(rc));

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return false;

180

}

181

182

ret = (int)TEMP_FAILURE_RETRY(close(fd));

183

if(ret == -1){

184

perror("close");

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}

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gpgme_data_release(pgp_data);

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return true;

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}

189

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if(debug){

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fprintf(stderr, "Initialize gpgme\n");

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192

}

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/* Init GPGME */

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gpgme_check_version(NULL);

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rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);

157

if (rc != GPG_ERR_NO_ERROR){

197

if(rc != GPG_ERR_NO_ERROR){

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198

fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",

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gpgme_strsource(rc), gpgme_strerror(rc));

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return -1;

200

return false;

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201

}

162

202

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/* Set GPGME home directory for the OpenPGP engine only */

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rc = gpgme_get_engine_info (&engine_info);

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if (rc != GPG_ERR_NO_ERROR){

203

/* Set GPGME home directory for the OpenPGP engine only */

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rc = gpgme_get_engine_info(&engine_info);

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if(rc != GPG_ERR_NO_ERROR){

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fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",

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gpgme_strsource(rc), gpgme_strerror(rc));

168

return -1;

208

return false;

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}

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while(engine_info != NULL){

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211

if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){

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212

gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,

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engine_info->file_name, homedir);

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engine_info->file_name, tempdir);

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break;

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}

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engine_info = engine_info->next;

177

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}

178

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if(engine_info == NULL){

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fprintf(stderr, "Could not set GPGME home dir to %s\n", homedir);

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return -1;

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fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);

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return false;

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}

222

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/* Create new GPGME "context" */

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rc = gpgme_new(&(mc->ctx));

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if(rc != GPG_ERR_NO_ERROR){

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fprintf(stderr, "bad gpgme_new: %s: %s\n",

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gpgme_strsource(rc), gpgme_strerror(rc));

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return false;

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}

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if(not import_key(pubkey) or not import_key(seckey)){

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return false;

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}

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return true;

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}

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/*

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* Decrypt OpenPGP data.

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* Returns -1 on error

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*/

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static ssize_t pgp_packet_decrypt(const mandos_context *mc,

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const char *cryptotext,

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size_t crypto_size,

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char **plaintext){

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gpgme_data_t dh_crypto, dh_plain;

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gpgme_error_t rc;

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ssize_t ret;

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size_t plaintext_capacity = 0;

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ssize_t plaintext_length = 0;

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if(debug){

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fprintf(stderr, "Trying to decrypt OpenPGP data\n");

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}

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/* Create new GPGME data buffer from memory cryptotext */

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rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,

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0);

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if (rc != GPG_ERR_NO_ERROR){

259

if(rc != GPG_ERR_NO_ERROR){

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fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",

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gpgme_strsource(rc), gpgme_strerror(rc));

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return -1;

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/* Create new empty GPGME data buffer for the plaintext */

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rc = gpgme_data_new(&dh_plain);

194

if (rc != GPG_ERR_NO_ERROR){

267

if(rc != GPG_ERR_NO_ERROR){

195

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fprintf(stderr, "bad gpgme_data_new: %s: %s\n",

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gpgme_strsource(rc), gpgme_strerror(rc));

197

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gpgme_data_release(dh_crypto);

198

271

return -1;

199

272

}

200

273

201

/* Create new GPGME "context" */

202

rc = gpgme_new(&ctx);

203

if (rc != GPG_ERR_NO_ERROR){

204

fprintf(stderr, "bad gpgme_new: %s: %s\n",

205

gpgme_strsource(rc), gpgme_strerror(rc));

206

plaintext_length = -1;

207

goto decrypt_end;

208

}

209

210

274

/* Decrypt data from the cryptotext data buffer to the plaintext

211

275

data buffer */

212

rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);

213

if (rc != GPG_ERR_NO_ERROR){

276

rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);

277

if(rc != GPG_ERR_NO_ERROR){

214

278

fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",

215

279

gpgme_strsource(rc), gpgme_strerror(rc));

216

280

plaintext_length = -1;

281

if(debug){

282

gpgme_decrypt_result_t result;

283

result = gpgme_op_decrypt_result(mc->ctx);

284

if(result == NULL){

285

fprintf(stderr, "gpgme_op_decrypt_result failed\n");

286

} else {

287

fprintf(stderr, "Unsupported algorithm: %s\n",

288

result->unsupported_algorithm);

289

fprintf(stderr, "Wrong key usage: %u\n",

290

result->wrong_key_usage);

291

if(result->file_name != NULL){

292

fprintf(stderr, "File name: %s\n", result->file_name);

293

}

294

gpgme_recipient_t recipient;

295

recipient = result->recipients;

296

if(recipient){

297

while(recipient != NULL){

298

fprintf(stderr, "Public key algorithm: %s\n",

299

gpgme_pubkey_algo_name(recipient->pubkey_algo));

300

fprintf(stderr, "Key ID: %s\n", recipient->keyid);

301

fprintf(stderr, "Secret key available: %s\n",

302

recipient->status == GPG_ERR_NO_SECKEY

303

? "No" : "Yes");

304

recipient = recipient->next;

305

}

306

}

307

}

308

}

217

309

goto decrypt_end;

218

310

}

219

311

221

313

fprintf(stderr, "Decryption of OpenPGP data succeeded\n");

222

314

}

223

315

224

if (debug){

225

gpgme_decrypt_result_t result;

226

result = gpgme_op_decrypt_result(ctx);

227

if (result == NULL){

228

fprintf(stderr, "gpgme_op_decrypt_result failed\n");

229

} else {

230

fprintf(stderr, "Unsupported algorithm: %s\n",

231

result->unsupported_algorithm);

232

fprintf(stderr, "Wrong key usage: %u\n",

233

result->wrong_key_usage);

234

if(result->file_name != NULL){

235

fprintf(stderr, "File name: %s\n", result->file_name);

236

}

237

gpgme_recipient_t recipient;

238

recipient = result->recipients;

239

if(recipient){

240

while(recipient != NULL){

241

fprintf(stderr, "Public key algorithm: %s\n",

242

gpgme_pubkey_algo_name(recipient->pubkey_algo));

243

fprintf(stderr, "Key ID: %s\n", recipient->keyid);

244

fprintf(stderr, "Secret key available: %s\n",

245

recipient->status == GPG_ERR_NO_SECKEY

246

? "No" : "Yes");

247

recipient = recipient->next;

248

}

249

}

250

}

251

}

252

253

316

/* Seek back to the beginning of the GPGME plaintext data buffer */

254

if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){

255

perror("pgpme_data_seek");

317

if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){

318

perror("gpgme_data_seek");

256

319

plaintext_length = -1;

257

320

goto decrypt_end;

258

321

}

262

325

plaintext_capacity = adjustbuffer(plaintext,

263

326

(size_t)plaintext_length,

264

327

plaintext_capacity);

265

if (plaintext_capacity == 0){

328

if(plaintext_capacity == 0){

266

329

perror("adjustbuffer");

267

330

plaintext_length = -1;

268

331

goto decrypt_end;

271

334

ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,

272

335

BUFFER_SIZE);

273

336

/* Print the data, if any */

274

if (ret == 0){

337

if(ret == 0){

275

338

/* EOF */

276

339

break;

277

340

}

282

345

}

283

346

plaintext_length += ret;

284

347

}

285

348

286

349

if(debug){

287

350

fprintf(stderr, "Decrypted password is: ");

288

351

for(ssize_t i = 0; i < plaintext_length; i++){

301

364

return plaintext_length;

302

365

}

303

366

304

static const char * safer_gnutls_strerror (int value) {

305

const char *ret = gnutls_strerror (value);

306

if (ret == NULL)

367

static const char * safer_gnutls_strerror(int value) {

368

const char *ret = gnutls_strerror(value); /* Spurious warning */

369

if(ret == NULL)

307

370

ret = "(unknown)";

308

371

return ret;

309

372

}

315

378

}

316

379

317

380

static int init_gnutls_global(mandos_context *mc,

318

const char *pubkeyfile,

319

const char *seckeyfile){

381

const char *pubkeyfilename,

382

const char *seckeyfilename){

320

383

int ret;

321

384

322

385

if(debug){

324

387

}

325

388

326

389

ret = gnutls_global_init();

327

if (ret != GNUTLS_E_SUCCESS) {

328

fprintf (stderr, "GnuTLS global_init: %s\n",

329

safer_gnutls_strerror(ret));

390

if(ret != GNUTLS_E_SUCCESS) {

391

fprintf(stderr, "GnuTLS global_init: %s\n",

392

safer_gnutls_strerror(ret));

330

393

return -1;

331

394

}

332

395

333

if (debug){

396

if(debug){

334

397

/* "Use a log level over 10 to enable all debugging options."

335

398

* - GnuTLS manual

336

399

*/

340

403

341

404

/* OpenPGP credentials */

342

405

gnutls_certificate_allocate_credentials(&mc->cred);

343

if (ret != GNUTLS_E_SUCCESS){

344

fprintf (stderr, "GnuTLS memory error: %s\n",

345

safer_gnutls_strerror(ret));

346

gnutls_global_deinit ();

406

if(ret != GNUTLS_E_SUCCESS){

407

fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious

408

warning */

409

safer_gnutls_strerror(ret));

410

gnutls_global_deinit();

347

411

return -1;

348

412

}

349

413

350

414

if(debug){

351

fprintf(stderr, "Attempting to use OpenPGP certificate %s"

352

" and keyfile %s as GnuTLS credentials\n", pubkeyfile,

353

seckeyfile);

415

fprintf(stderr, "Attempting to use OpenPGP public key %s and"

416

" secret key %s as GnuTLS credentials\n", pubkeyfilename,

417

seckeyfilename);

354

418

}

355

419

356

420

ret = gnutls_certificate_set_openpgp_key_file

357

(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);

358

if (ret != GNUTLS_E_SUCCESS) {

421

(mc->cred, pubkeyfilename, seckeyfilename,

422

GNUTLS_OPENPGP_FMT_BASE64);

423

if(ret != GNUTLS_E_SUCCESS) {

359

424

fprintf(stderr,

360

425

"Error[%d] while reading the OpenPGP key pair ('%s',"

361

" '%s')\n", ret, pubkeyfile, seckeyfile);

362

fprintf(stdout, "The GnuTLS error is: %s\n",

426

" '%s')\n", ret, pubkeyfilename, seckeyfilename);

427

fprintf(stderr, "The GnuTLS error is: %s\n",

363

428

safer_gnutls_strerror(ret));

364

429

goto globalfail;

365

430

}

366

431

367

432

/* GnuTLS server initialization */

368

433

ret = gnutls_dh_params_init(&mc->dh_params);

369

if (ret != GNUTLS_E_SUCCESS) {

370

fprintf (stderr, "Error in GnuTLS DH parameter initialization:"

371

" %s\n", safer_gnutls_strerror(ret));

434

if(ret != GNUTLS_E_SUCCESS) {

435

fprintf(stderr, "Error in GnuTLS DH parameter initialization:"

436

" %s\n", safer_gnutls_strerror(ret));

372

437

goto globalfail;

373

438

}

374

439

ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);

375

if (ret != GNUTLS_E_SUCCESS) {

376

fprintf (stderr, "Error in GnuTLS prime generation: %s\n",

377

safer_gnutls_strerror(ret));

440

if(ret != GNUTLS_E_SUCCESS) {

441

fprintf(stderr, "Error in GnuTLS prime generation: %s\n",

442

safer_gnutls_strerror(ret));

378

443

goto globalfail;

379

444

}

380

445

381

446

gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);

382

447

383

448

return 0;

384

449

385

450

globalfail:

386

451

387

452

gnutls_certificate_free_credentials(mc->cred);

388

453

gnutls_global_deinit();

454

gnutls_dh_params_deinit(mc->dh_params);

389

455

return -1;

390

391

456

}

392

457

393

458

static int init_gnutls_session(mandos_context *mc,

395

460

int ret;

396

461

/* GnuTLS session creation */

397

462

ret = gnutls_init(session, GNUTLS_SERVER);

398

if (ret != GNUTLS_E_SUCCESS){

463

if(ret != GNUTLS_E_SUCCESS){

399

464

fprintf(stderr, "Error in GnuTLS session initialization: %s\n",

400

465

safer_gnutls_strerror(ret));

401

466

}

403

468

{

404

469

const char *err;

405

470

ret = gnutls_priority_set_direct(*session, mc->priority, &err);

406

if (ret != GNUTLS_E_SUCCESS) {

471

if(ret != GNUTLS_E_SUCCESS) {

407

472

fprintf(stderr, "Syntax error at: %s\n", err);

408

473

fprintf(stderr, "GnuTLS error: %s\n",

409

474

safer_gnutls_strerror(ret));

410

gnutls_deinit (*session);

475

gnutls_deinit(*session);

411

476

return -1;

412

477

}

413

478

}

414

479

415

480

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

416

481

mc->cred);

417

if (ret != GNUTLS_E_SUCCESS) {

482

if(ret != GNUTLS_E_SUCCESS) {

418

483

fprintf(stderr, "Error setting GnuTLS credentials: %s\n",

419

484

safer_gnutls_strerror(ret));

420

gnutls_deinit (*session);

485

gnutls_deinit(*session);

421

486

return -1;

422

487

}

423

488

424

489

/* ignore client certificate if any. */

425

gnutls_certificate_server_set_request (*session,

426

GNUTLS_CERT_IGNORE);

490

gnutls_certificate_server_set_request(*session,

491

GNUTLS_CERT_IGNORE);

427

492

428

gnutls_dh_set_prime_bits (*session, mc->dh_bits);

493

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

429

494

430

495

return 0;

431

496

}

439

504

AvahiIfIndex if_index,

440

505

mandos_context *mc){

441

506

int ret, tcp_sd;

507

ssize_t sret;

442

508

union { struct sockaddr in; struct sockaddr_in6 in6; } to;

443

509

char *buffer = NULL;

444

510

char *decrypted_buffer;

450

516

char interface[IF_NAMESIZE];

451

517

gnutls_session_t session;

452

518

453

ret = init_gnutls_session (mc, &session);

454

if (ret != 0){

519

ret = init_gnutls_session(mc, &session);

520

if(ret != 0){

455

521

return -1;

456

522

}

457

523

465

531

perror("socket");

466

532

return -1;

467

533

}

468

534

469

535

if(debug){

470

536

if(if_indextoname((unsigned int)if_index, interface) == NULL){

471

537

perror("if_indextoname");

474

540

fprintf(stderr, "Binding to interface %s\n", interface);

475

541

}

476

542

477

memset(&to,0,sizeof(to)); /* Spurious warning */

543

memset(&to, 0, sizeof(to));

478

544

to.in6.sin6_family = AF_INET6;

479

545

/* It would be nice to have a way to detect if we were passed an

480

546

IPv4 address here. Now we assume an IPv6 address. */

481

547

ret = inet_pton(AF_INET6, ip, &to.in6.sin6_addr);

482

if (ret < 0 ){

548

if(ret < 0 ){

483

549

perror("inet_pton");

484

550

return -1;

485

551

}

487

553

fprintf(stderr, "Bad address: %s\n", ip);

488

554

return -1;

489

555

}

490

to.in6.sin6_port = htons(port); /* Spurious warning */

556

to.in6.sin6_port = htons(port); /* Spurious warning */

491

557

492

558

to.in6.sin6_scope_id = (uint32_t)if_index;

493

559

506

572

}

507

573

508

574

ret = connect(tcp_sd, &to.in, sizeof(to));

509

if (ret < 0){

575

if(ret < 0){

510

576

perror("connect");

511

577

return -1;

512

578

}

513

579

514

580

const char *out = mandos_protocol_version;

515

581

written = 0;

516

while (true){

582

while(true){

517

583

size_t out_size = strlen(out);

518

ret = TEMP_FAILURE_RETRY(write(tcp_sd, out + written,

584

ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,

519

585

out_size - written));

520

if (ret == -1){

586

if(ret == -1){

521

587

perror("write");

522

588

retval = -1;

523

589

goto mandos_end;

526

592

if(written < out_size){

527

593

continue;

528

594

} else {

529

if (out == mandos_protocol_version){

595

if(out == mandos_protocol_version){

530

596

written = 0;

531

597

out = "\r\n";

532

598

} else {

534

600

}

535

601

}

536

602

}

537

603

538

604

if(debug){

539

605

fprintf(stderr, "Establishing TLS session with %s\n", ip);

540

606

}

541

607

542

gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) tcp_sd);

543

608

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

609

544

610

do{

545

ret = gnutls_handshake (session);

611

ret = gnutls_handshake(session);

546

612

} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);

547

613

548

if (ret != GNUTLS_E_SUCCESS){

614

if(ret != GNUTLS_E_SUCCESS){

549

615

if(debug){

550

616

fprintf(stderr, "*** GnuTLS Handshake failed ***\n");

551

gnutls_perror (ret);

617

gnutls_perror(ret);

552

618

}

553

619

retval = -1;

554

620

goto mandos_end;

560

626

fprintf(stderr, "Retrieving pgp encrypted password from %s\n",

561

627

ip);

562

628

}

563

629

564

630

while(true){

565

631

buffer_capacity = adjustbuffer(&buffer, buffer_length,

566

632

buffer_capacity);

567

if (buffer_capacity == 0){

633

if(buffer_capacity == 0){

568

634

perror("adjustbuffer");

569

635

retval = -1;

570

636

goto mandos_end;

571

637

}

572

638

573

ret = gnutls_record_recv(session, buffer+buffer_length,

574

BUFFER_SIZE);

575

if (ret == 0){

639

sret = gnutls_record_recv(session, buffer+buffer_length,

640

BUFFER_SIZE);

641

if(sret == 0){

576

642

break;

577

643

}

578

if (ret < 0){

579

switch(ret){

644

if(sret < 0){

645

switch(sret){

580

646

case GNUTLS_E_INTERRUPTED:

581

647

case GNUTLS_E_AGAIN:

582

648

break;

583

649

case GNUTLS_E_REHANDSHAKE:

584

650

do{

585

ret = gnutls_handshake (session);

651

ret = gnutls_handshake(session);

586

652

} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);

587

if (ret < 0){

653

if(ret < 0){

588

654

fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");

589

gnutls_perror (ret);

655

gnutls_perror(ret);

590

656

retval = -1;

591

657

goto mandos_end;

592

658

}

595

661

fprintf(stderr, "Unknown error while reading data from"

596

662

" encrypted session with Mandos server\n");

597

663

retval = -1;

598

gnutls_bye (session, GNUTLS_SHUT_RDWR);

664

gnutls_bye(session, GNUTLS_SHUT_RDWR);

599

665

goto mandos_end;

600

666

}

601

667

} else {

602

buffer_length += (size_t) ret;

668

buffer_length += (size_t) sret;

603

669

}

604

670

}

605

671

607

673

fprintf(stderr, "Closing TLS session\n");

608

674

}

609

675

610

gnutls_bye (session, GNUTLS_SHUT_RDWR);

676

gnutls_bye(session, GNUTLS_SHUT_RDWR);

611

677

612

if (buffer_length > 0){

613

decrypted_buffer_size = pgp_packet_decrypt(buffer,

678

if(buffer_length > 0){

679

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

614

680

buffer_length,

615

&decrypted_buffer,

616

keydir);

617

if (decrypted_buffer_size >= 0){

681

&decrypted_buffer);

682

if(decrypted_buffer_size >= 0){

618

683

written = 0;

619

684

while(written < (size_t) decrypted_buffer_size){

620

ret = (int)fwrite (decrypted_buffer + written, 1,

621

(size_t)decrypted_buffer_size - written,

622

stdout);

685

ret = (int)fwrite(decrypted_buffer + written, 1,

686

(size_t)decrypted_buffer_size - written,

687

stdout);

623

688

if(ret == 0 and ferror(stdout)){

624

689

if(debug){

625

690

fprintf(stderr, "Error writing encrypted data: %s\n",

634

699

} else {

635

700

retval = -1;

636

701

}

702

} else {

703

retval = -1;

637

704

}

638

705

639

706

/* Shutdown procedure */

640

707

641

708

mandos_end:

642

709

free(buffer);

643

close(tcp_sd);

644

gnutls_deinit (session);

710

ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));

711

if(ret == -1){

712

perror("close");

713

}

714

gnutls_deinit(session);

645

715

return retval;

646

716

}

647

717

660

730

flags,

661

731

void* userdata) {

662

732

mandos_context *mc = userdata;

663

assert(r); /* Spurious warning */

733

assert(r);

664

734

665

735

/* Called whenever a service has been resolved successfully or

666

736

timed out */

667

737

668

switch (event) {

738

switch(event) {

669

739

default:

670

740

case AVAHI_RESOLVER_FAILURE:

671

741

fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"

683

753

interface, port);

684

754

}

685

755

int ret = start_mandos_communication(ip, port, interface, mc);

686

if (ret == 0){

687

exit(EXIT_SUCCESS);

756

if(ret == 0){

757

avahi_simple_poll_quit(mc->simple_poll);

688

758

}

689

759

}

690

760

}

702

772

flags,

703

773

void* userdata) {

704

774

mandos_context *mc = userdata;

705

assert(b); /* Spurious warning */

775

assert(b);

706

776

707

777

/* Called whenever a new services becomes available on the LAN or

708

778

is removed from the LAN */

709

779

710

switch (event) {

780

switch(event) {

711

781

default:

712

782

case AVAHI_BROWSER_FAILURE:

713

783

722

792

the callback function is called the Avahi server will free the

723

793

resolver for us. */

724

794

725

if (!(avahi_s_service_resolver_new(mc->server, interface,

795

if(!(avahi_s_service_resolver_new(mc->server, interface,

726

796

protocol, name, type, domain,

727

797

AVAHI_PROTO_INET6, 0,

728

798

resolve_callback, mc)))

742

812

}

743

813

}

744

814

745

/* Combines file name and path and returns the malloced new

746

string. some sane checks could/should be added */

747

static const char *combinepath(const char *first, const char *second){

748

size_t f_len = strlen(first);

749

size_t s_len = strlen(second);

750

char *tmp = malloc(f_len + s_len + 2);

751

if (tmp == NULL){

752

return NULL;

753

}

754

if(f_len > 0){

755

memcpy(tmp, first, f_len); /* Spurious warning */

756

}

757

tmp[f_len] = '/';

758

if(s_len > 0){

759

memcpy(tmp + f_len + 1, second, s_len); /* Spurious warning */

760

}

761

tmp[f_len + 1 + s_len] = '\0';

762

return tmp;

763

}

764

765

766

815

int main(int argc, char *argv[]){

767

816

AvahiSServiceBrowser *sb = NULL;

768

817

int error;

774

823

uid_t uid;

775

824

gid_t gid;

776

825

char *connect_to = NULL;

826

char tempdir[] = "/tmp/mandosXXXXXX";

777

827

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

778

const char *pubkeyfile = "pubkey.txt";

779

const char *seckeyfile = "seckey.txt";

828

const char *seckey = PATHDIR "/" SECKEY;

829

const char *pubkey = PATHDIR "/" PUBKEY;

830

780

831

mandos_context mc = { .simple_poll = NULL, .server = NULL,

781

.dh_bits = 1024, .priority = "SECURE256"};

832

.dh_bits = 1024, .priority = "SECURE256"

833

":!CTYPE-X.509:+CTYPE-OPENPGP" };

782

834

bool gnutls_initalized = false;

835

bool gpgme_initalized = false;

783

836

784

837

{

785

838

struct argp_option options[] = {

786

839

{ .name = "debug", .key = 128,

787

840

.doc = "Debug mode", .group = 3 },

788

841

{ .name = "connect", .key = 'c',

789

.arg = "IP",

790

.doc = "Connect directly to a sepcified mandos server",

842

.arg = "ADDRESS:PORT",

843

.doc = "Connect directly to a specific Mandos server",

791

844

.group = 1 },

792

845

{ .name = "interface", .key = 'i',

793

.arg = "INTERFACE",

794

.doc = "Interface that Avahi will conntect through",

795

.group = 1 },

796

{ .name = "keydir", .key = 'd',

797

.arg = "KEYDIR",

798

.doc = "Directory where the openpgp keyring is",

846

.arg = "NAME",

847

.doc = "Interface that will be used to search for Mandos"

848

" servers",

799

849

.group = 1 },

800

850

{ .name = "seckey", .key = 's',

801

.arg = "SECKEY",

802

.doc = "Secret openpgp key for gnutls authentication",

851

.arg = "FILE",

852

.doc = "OpenPGP secret key file base name",

803

853

.group = 1 },

804

854

{ .name = "pubkey", .key = 'p',

805

.arg = "PUBKEY",

806

.doc = "Public openpgp key for gnutls authentication",

855

.arg = "FILE",

856

.doc = "OpenPGP public key file base name",

807

857

.group = 2 },

808

858

{ .name = "dh-bits", .key = 129,

809

859

.arg = "BITS",

810

.doc = "dh-bits to use in gnutls communication",

860

.doc = "Bit length of the prime number used in the"

861

" Diffie-Hellman key exchange",

811

862

.group = 2 },

812

863

{ .name = "priority", .key = 130,

813

.arg = "PRIORITY",

814

.doc = "GNUTLS priority", .group = 1 },

864

.arg = "STRING",

865

.doc = "GnuTLS priority string for the TLS handshake",

866

.group = 1 },

815

867

{ .name = NULL }

816

868

};

817

818

869

819

error_t parse_opt (int key, char *arg,

820

struct argp_state *state) {

821

/* Get the INPUT argument from `argp_parse', which we know is

822

a pointer to our plugin list pointer. */

823

switch (key) {

824

case 128:

870

error_t parse_opt(int key, char *arg,

871

struct argp_state *state) {

872

switch(key) {

873

case 128: /* --debug */

825

874

debug = true;

826

875

break;

827

case 'c':

876

case 'c': /* --connect */

828

877

connect_to = arg;

829

878

break;

830

case 'i':

879

case 'i': /* --interface */

831

880

interface = arg;

832

881

break;

833

case 'd':

834

keydir = arg;

835

break;

836

case 's':

837

seckeyfile = arg;

838

break;

839

case 'p':

840

pubkeyfile = arg;

841

break;

842

case 129:

843

errno = 0;

844

mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);

845

if (errno){

846

perror("strtol");

882

case 's': /* --seckey */

883

seckey = arg;

884

break;

885

case 'p': /* --pubkey */

886

pubkey = arg;

887

break;

888

case 129: /* --dh-bits */

889

ret = sscanf(arg, "%u", &mc.dh_bits);

890

if(ret != 1){

891

fprintf(stderr, "Bad number of DH bits\n");

847

892

exit(EXIT_FAILURE);

848

893

}

849

894

break;

850

case 130:

895

case 130: /* --priority */

851

896

mc.priority = arg;

852

897

break;

853

898

case ARGP_KEY_ARG:

854

argp_usage (state);

899

argp_usage(state);

900

case ARGP_KEY_END:

855

901

break;

856

case ARGP_KEY_END:

857

break;

858

902

default:

859

903

return ARGP_ERR_UNKNOWN;

860

904

}

861

905

return 0;

862

906

}

863

907

864

908

struct argp argp = { .options = options, .parser = parse_opt,

865

909

.args_doc = "",

866

910

.doc = "Mandos client -- Get and decrypt"

867

" passwords from mandos server" };

868

ret = argp_parse (&argp, argc, argv, 0, 0, NULL);

869

if (ret == ARGP_ERR_UNKNOWN){

870

fprintf(stderr, "Unkown error while parsing arguments\n");

871

exitcode = EXIT_FAILURE;

872

goto end;

873

}

874

}

875

876

pubkeyfile = combinepath(keydir, pubkeyfile);

877

if (pubkeyfile == NULL){

878

perror("combinepath");

879

exitcode = EXIT_FAILURE;

880

goto end;

881

}

882

883

seckeyfile = combinepath(keydir, seckeyfile);

884

if (seckeyfile == NULL){

885

perror("combinepath");

886

goto end;

887

}

888

889

ret = init_gnutls_global(&mc, pubkeyfile, seckeyfile);

890

if (ret == -1){

891

fprintf(stderr, "init_gnutls_global\n");

892

goto end;

893

} else {

894

gnutls_initalized = true;

895

}

896

911

" passwords from a Mandos server" };

912

ret = argp_parse(&argp, argc, argv, 0, 0, NULL);

913

if(ret == ARGP_ERR_UNKNOWN){

914

fprintf(stderr, "Unknown error while parsing arguments\n");

915

exitcode = EXIT_FAILURE;

916

goto end;

917

}

918

}

919

920

/* If the interface is down, bring it up */

921

{

922

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

923

if(sd < 0) {

924

perror("socket");

925

exitcode = EXIT_FAILURE;

926

goto end;

927

}

928

strcpy(network.ifr_name, interface);

929

ret = ioctl(sd, SIOCGIFFLAGS, &network);

930

if(ret == -1){

931

perror("ioctl SIOCGIFFLAGS");

932

exitcode = EXIT_FAILURE;

933

goto end;

934

}

935

if((network.ifr_flags & IFF_UP) == 0){

936

network.ifr_flags |= IFF_UP;

937

ret = ioctl(sd, SIOCSIFFLAGS, &network);

938

if(ret == -1){

939

perror("ioctl SIOCSIFFLAGS");

940

exitcode = EXIT_FAILURE;

941

goto end;

942

}

943

}

944

ret = (int)TEMP_FAILURE_RETRY(close(sd));

945

if(ret == -1){

946

perror("close");

947

}

948

}

949

897

950

uid = getuid();

898

951

gid = getgid();

899

952

900

953

ret = setuid(uid);

901

if (ret == -1){

954

if(ret == -1){

902

955

perror("setuid");

903

956

}

904

957

905

958

setgid(gid);

906

if (ret == -1){

959

if(ret == -1){

907

960

perror("setgid");

908

961

}

909

962

963

ret = init_gnutls_global(&mc, pubkey, seckey);

964

if(ret == -1){

965

fprintf(stderr, "init_gnutls_global failed\n");

966

exitcode = EXIT_FAILURE;

967

goto end;

968

} else {

969

gnutls_initalized = true;

970

}

971

972

if(mkdtemp(tempdir) == NULL){

973

perror("mkdtemp");

974

tempdir[0] = '\0';

975

goto end;

976

}

977

978

if(not init_gpgme(&mc, pubkey, seckey, tempdir)){

979

fprintf(stderr, "gpgme_initalized failed\n");

980

exitcode = EXIT_FAILURE;

981

goto end;

982

} else {

983

gpgme_initalized = true;

984

}

985

910

986

if_index = (AvahiIfIndex) if_nametoindex(interface);

911

987

if(if_index == 0){

912

988

fprintf(stderr, "No such interface: \"%s\"\n", interface);

922

998

exitcode = EXIT_FAILURE;

923

999

goto end;

924

1000

}

925

errno = 0;

926

uint16_t port = (uint16_t) strtol(address+1, NULL, 10);

927

if(errno){

928

perror("Bad port number");

1001

uint16_t port;

1002

ret = sscanf(address+1, "%" SCNu16, &port);

1003

if(ret != 1){

1004

fprintf(stderr, "Bad port number\n");

929

1005

exitcode = EXIT_FAILURE;

930

1006

goto end;

931

1007

}

940

1016

goto end;

941

1017

}

942

1018

943

/* If the interface is down, bring it up */

944

{

945

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

946

if(sd < 0) {

947

perror("socket");

948

exitcode = EXIT_FAILURE;

949

goto end;

950

}

951

strcpy(network.ifr_name, interface); /* Spurious warning */

952

ret = ioctl(sd, SIOCGIFFLAGS, &network);

953

if(ret == -1){

954

perror("ioctl SIOCGIFFLAGS");

955

exitcode = EXIT_FAILURE;

956

goto end;

957

}

958

if((network.ifr_flags & IFF_UP) == 0){

959

network.ifr_flags |= IFF_UP;

960

ret = ioctl(sd, SIOCSIFFLAGS, &network);

961

if(ret == -1){

962

perror("ioctl SIOCSIFFLAGS");

963

exitcode = EXIT_FAILURE;

964

goto end;

965

}

966

}

967

close(sd);

968

}

969

970

if (not debug){

1019

if(not debug){

971

1020

avahi_set_log_function(empty_log);

972

1021

}

973

1022

976

1025

977

1026

/* Allocate main Avahi loop object */

978

1027

mc.simple_poll = avahi_simple_poll_new();

979

if (mc.simple_poll == NULL) {

1028

if(mc.simple_poll == NULL) {

980

1029

fprintf(stderr, "Avahi: Failed to create simple poll"

981

1030

" object.\n");

982

1031

exitcode = EXIT_FAILURE;

983

1032

goto end;

984

1033

}

985

1034

986

1035

{

987

1036

AvahiServerConfig config;

988

1037

/* Do not publish any local Zeroconf records */

991

1040

config.publish_addresses = 0;

992

1041

config.publish_workstation = 0;

993

1042

config.publish_domain = 0;

994

1043

995

1044

/* Allocate a new server */

996

1045

mc.server = avahi_server_new(avahi_simple_poll_get

997

1046

(mc.simple_poll), &config, NULL,

998

1047

NULL, &error);

999

1048

1000

1049

/* Free the Avahi configuration data */

1001

1050

avahi_server_config_free(&config);

1002

1051

}

1003

1052

1004

1053

/* Check if creating the Avahi server object succeeded */

1005

if (mc.server == NULL) {

1054

if(mc.server == NULL) {

1006

1055

fprintf(stderr, "Failed to create Avahi server: %s\n",

1007

1056

avahi_strerror(error));

1008

1057

exitcode = EXIT_FAILURE;

1014

1063

AVAHI_PROTO_INET6,

1015

1064

"_mandos._tcp", NULL, 0,

1016

1065

browse_callback, &mc);

1017

if (sb == NULL) {

1066

if(sb == NULL) {

1018

1067

fprintf(stderr, "Failed to create service browser: %s\n",

1019

1068

avahi_strerror(avahi_server_errno(mc.server)));

1020

1069

exitcode = EXIT_FAILURE;

1022

1071

}

1023

1072

1024

1073

/* Run the main loop */

1025

1026

if (debug){

1074

1075

if(debug){

1027

1076

fprintf(stderr, "Starting Avahi loop search\n");

1028

1077

}

1029

1078

1030

1079

avahi_simple_poll_loop(mc.simple_poll);

1031

1080

1032

1081

end:

1033

1034

if (debug){

1082

1083

if(debug){

1035

1084

fprintf(stderr, "%s exiting\n", argv[0]);

1036

1085

}

1037

1086

1038

1087

/* Cleanup things */

1039

if (sb != NULL)

1088

if(sb != NULL)

1040

1089

avahi_s_service_browser_free(sb);

1041

1090

1042

if (mc.server != NULL)

1091

if(mc.server != NULL)

1043

1092

avahi_server_free(mc.server);

1044

1045

if (mc.simple_poll != NULL)

1093

1094

if(mc.simple_poll != NULL)

1046

1095

avahi_simple_poll_free(mc.simple_poll);

1047

free(pubkeyfile);

1048

free(seckeyfile);

1049

1050

if (gnutls_initalized){

1096

1097

if(gnutls_initalized){

1051

1098

gnutls_certificate_free_credentials(mc.cred);

1052

gnutls_global_deinit ();

1053

}

1054

1099

gnutls_global_deinit();

1100

gnutls_dh_params_deinit(mc.dh_params);

1101

}

1102

1103

if(gpgme_initalized){

1104

gpgme_release(mc.ctx);

1105

}

1106

1107

/* Removes the temp directory used by GPGME */

1108

if(tempdir[0] != '\0'){

1109

DIR *d;

1110

struct dirent *direntry;

1111

d = opendir(tempdir);

1112

if(d == NULL){

1113

if(errno != ENOENT){

1114

perror("opendir");

1115

}

1116

} else {

1117

while(true){

1118

direntry = readdir(d);

1119

if(direntry == NULL){

1120

break;

1121

}

1122

if(direntry->d_type == DT_REG){

1123

char *fullname = NULL;

1124

ret = asprintf(&fullname, "%s/%s", tempdir,

1125

direntry->d_name);

1126

if(ret < 0){

1127

perror("asprintf");

1128

continue;

1129

}

1130

ret = unlink(fullname);

1131

if(ret == -1){

1132

fprintf(stderr, "unlink(\"%s\"): %s",

1133

fullname, strerror(errno));

1134

}

1135

free(fullname);

1136

}

1137

}

1138

closedir(d);

1139

}

1140

ret = rmdir(tempdir);

1141

if(ret == -1 and errno != ENOENT){

1142

perror("rmdir");

1143

}

1144

}

1145

1055

1146

return exitcode;

1056

1147

}