/mandos/trunk : revision 237.4.53

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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 file is part of Mandos.

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*

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* Mandos is free software: you can redistribute it and/or modify it

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* under the terms of the GNU General Public License as published by

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* the Free Software Foundation, either version 3 of the License, or

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* (at your option) any later version.

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*

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* Mandos is distributed in the hope that it will be useful, but

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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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* 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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*

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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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22

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

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* General Public License for more details.

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*

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* You should have received a copy of the GNU General Public License

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* along with Mandos. If not, see <http://www.gnu.org/licenses/>.

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* along with this program. If not, see

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* <http://www.gnu.org/licenses/>.

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*

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* Contact the authors at <mandos@recompile.se>.

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*/

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#define _FILE_OFFSET_BITS 64

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38

#endif /* not _FILE_OFFSET_BITS */

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#define _GNU_SOURCE /* program_invocation_short_name,

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TEMP_FAILURE_RETRY(), O_CLOEXEC,

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scandirat(), asprintf() */

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

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

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stdout, ferror() */

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

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

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

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strtof(), abort() */

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

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#include <argp.h> /* argp_program_version,

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argp_program_bug_address,

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struct argp_option,

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struct argp_state, argp_error(),

49

argp_state_help,

50

ARGP_HELP_STD_HELP,

51

ARGP_HELP_EXIT_ERR,

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ARGP_HELP_EXIT_OK, ARGP_HELP_USAGE,

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argp_err_exit_status,

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ARGP_ERR_UNKNOWN, struct argp,

55

argp_parse(), ARGP_IN_ORDER,

56

ARGP_NO_HELP */

57

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

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#include <sys/types.h> /* uid_t, gid_t, sig_atomic_t,

59

seteuid(), setuid(), pid_t,

60

setgid(), getuid(), getgid() */

61

#include <unistd.h> /* uid_t, gid_t, TEMP_FAILURE_RETRY(),

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seteuid(), setuid(), close(),

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ssize_t, read(), fork(), setgid(),

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_exit(), dup2(), STDIN_FILENO,

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STDERR_FILENO, STDOUT_FILENO,

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fexecve(), write(), getuid(),

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getgid(), fchown(), symlink(),

68

sleep(), unlinkat(), pause() */

69

#include <netinet/in.h> /* in_port_t, struct sockaddr_in6,

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sa_family_t, struct sockaddr_in,

71

htons(), IN6_IS_ADDR_LINKLOCAL,

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INET_ADDRSTRLEN, INET6_ADDRSTRLEN,

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ntohl(), IPPROTO_IP */

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#include <time.h> /* struct timespec, clock_gettime(),

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CLOCK_MONOTONIC, time_t, struct tm,

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gmtime_r(), clock_settime(),

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CLOCK_REALTIME, nanosleep() */

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#include <errno.h> /* errno,

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program_invocation_short_name,

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EINTR, EINVAL, ENETUNREACH,

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EHOSTUNREACH, ECONNREFUSED, EPROTO,

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EIO, ENOENT, ENXIO, error_t,

83

ENOMEM, EISDIR, ENOTEMPTY */

84

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

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vfprintf(), off_t, SEEK_SET,

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stdout, fwrite(), ferror(),

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fflush(), asprintf() */

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#include <stdarg.h> /* va_list, va_start(), vfprintf() */

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#include <stdlib.h> /* realloc(), free(), malloc(),

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getenv(), EXIT_FAILURE, setenv(),

91

EXIT_SUCCESS, strtof(), strtod(),

92

srand(), mkdtemp(), abort() */

93

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

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strerror(), strncpy(), strspn(),

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memcpy(), strrchr(), strchr(),

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strsignal() */

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

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O_PATH, O_CLOEXEC, openat(),

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O_NOFOLLOW, AT_REMOVEDIR */

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

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#include <sys/stat.h> /* struct stat, fstat(), fstatat(),

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S_ISREG(), S_IXUSR, S_IXGRP,

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S_IXOTH, lstat() */

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#include <net/if.h> /* IF_NAMESIZE, if_indextoname(),

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if_nametoindex(), SIOCGIFFLAGS,

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IFF_LOOPBACK, IFF_POINTOPOINT,

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IFF_BROADCAST, IFF_NOARP, IFF_UP,

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IFF_RUNNING, SIOCSIFFLAGS */

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#include <sysexits.h> /* EX_NOPERM, EX_OSERR,

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EX_UNAVAILABLE, EX_USAGE */

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

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

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

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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, uid_t, gid_t, open(),

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opendir(), DIR */

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

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#include <sys/socket.h> /* socket(), struct sockaddr_in6,

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inet_pton(), connect(),

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getnameinfo() */

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

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

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*/

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#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,

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strtoimax() */

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

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program_invocation_short_name */

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#include <time.h> /* nanosleep(), time(), sleep() */

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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> /* IN6_IS_ADDR_LINKLOCAL,

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INET_ADDRSTRLEN, INET6_ADDRSTRLEN

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*/

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

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getuid(), getgid(), seteuid(),

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setgid(), pause(), _exit(),

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unlinkat() */

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

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

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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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ARGP_KEY_END, ARGP_ERR_UNKNOWN */

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#include <signal.h> /* sigemptyset(), sigaddset(),

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sigaction(), SIGTERM, sig_atomic_t,

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raise() */

87

#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,

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EX_NOHOST, EX_IOERR, EX_PROTOCOL */

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#include <sys/wait.h> /* waitpid(), WIFEXITED(),

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WEXITSTATUS(), WTERMSIG() */

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#include <grp.h> /* setgroups() */

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#include <sys/wait.h> /* waitpid(), WIFEXITED(),

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WEXITSTATUS(), WIFSIGNALED(),

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WTERMSIG() */

115

#include <signal.h> /* kill(), SIGTERM, struct sigaction,

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SIG_DFL, sigemptyset(),

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sigaddset(), SIGINT, SIGHUP,

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SIG_IGN, raise() */

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#include <sys/socket.h> /* struct sockaddr_storage, AF_INET6,

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PF_INET6, AF_INET, PF_INET,

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socket(), SOCK_STREAM,

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SOCK_CLOEXEC, struct sockaddr,

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connect(), SOCK_DGRAM */

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#include <argz.h> /* argz_next(), argz_add_sep(),

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argz_delete(), argz_stringify(),

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argz_add(), argz_count() */

127

#include <inttypes.h> /* PRIuMAX, uintmax_t, uint32_t,

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PRIdMAX, PRIu16, intmax_t,

129

strtoimax() */

130

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

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

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#include <argz.h> /* argz_add_sep(), argz_next(),

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argz_delete(), argz_append(),

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argz_stringify(), argz_add(),

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argz_count() */

132

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#include <netdb.h> /* getnameinfo(), NI_NUMERICHOST,

133

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EAI_SYSTEM, gai_strerror() */

134

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

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

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alphasort(), scandir() */

137

#include <limits.h> /* INT_MAX */

138

98

139

99

#ifdef __linux__

140

100

#include <sys/klog.h> /* klogctl() */

153

113

154

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/* GnuTLS */

155

115

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

156

functions: gnutls_*, GNUTLS_* */

157

#if GNUTLS_VERSION_NUMBER < 0x030600

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functions:

117

gnutls_*

118

init_gnutls_session(),

119

GNUTLS_* */

158

120

#include <gnutls/openpgp.h>

159

121

/* gnutls_certificate_set_openpgp_key_file(),

160

122

GNUTLS_OPENPGP_FMT_BASE64 */

161

#elif GNUTLS_VERSION_NUMBER >= 0x030606

162

#include <gnutls/x509.h> /* GNUTLS_PKCS_PLAIN,

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GNUTLS_PKCS_NULL_PASSWORD */

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#endif

165

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/* GPGME */

167

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

168

126

functions:

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gpgme_*, GPG_ERR_NO_*,

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GPGME_IMPORT_*

171

GPGME_PROTOCOL_OpenPGP */

127

gpgme_*

128

GPGME_PROTOCOL_OpenPGP,

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GPG_ERR_NO_* */

172

130

173

131

#define BUFFER_SIZE 256

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132

175

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

176

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#define SECKEY "seckey.txt"

177

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#define PUBKEY "pubkey.txt"

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#define TLS_PRIVKEY "tls-privkey.pem"

179

#define TLS_PUBKEY "tls-pubkey.pem"

180

136

#define HOOKDIR "/lib/mandos/network-hooks.d"

181

137

182

138

bool debug = false;

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return true;

311

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}

312

268

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/* Set effective uid to 0, return errno */

314

__attribute__((warn_unused_result))

315

int raise_privileges(void){

316

int old_errno = errno;

317

int ret = 0;

318

if(seteuid(0) == -1){

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ret = errno;

320

}

321

errno = old_errno;

322

return ret;

323

}

324

325

/* Set effective and real user ID to 0. Return errno. */

326

__attribute__((warn_unused_result))

327

int raise_privileges_permanently(void){

328

int old_errno = errno;

329

int ret = raise_privileges();

330

if(ret != 0){

331

errno = old_errno;

332

return ret;

333

}

334

if(setuid(0) == -1){

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ret = errno;

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}

337

errno = old_errno;

338

return ret;

339

}

340

341

/* Set effective user ID to unprivileged saved user ID */

342

__attribute__((warn_unused_result))

343

int lower_privileges(void){

344

int old_errno = errno;

345

int ret = 0;

346

if(seteuid(uid) == -1){

347

ret = errno;

348

}

349

errno = old_errno;

350

return ret;

351

}

352

353

/* Lower privileges permanently */

354

__attribute__((warn_unused_result))

355

int lower_privileges_permanently(void){

356

int old_errno = errno;

357

int ret = 0;

358

if(setuid(uid) == -1){

359

ret = errno;

360

}

361

errno = old_errno;

362

return ret;

363

}

364

365

269

/*

366

270

* Initialize GPGME.

367

271

*/

387

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return false;

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292

}

389

293

390

/* Workaround for systems without a real-time clock; see also

391

Debian bug #894495: <https://bugs.debian.org/894495> */

392

do {

393

{

394

time_t currtime = time(NULL);

395

if(currtime != (time_t)-1){

396

struct tm tm;

397

if(gmtime_r(&currtime, &tm) == NULL) {

398

perror_plus("gmtime_r");

399

break;

400

}

401

if(tm.tm_year != 70 or tm.tm_mon != 0){

402

break;

403

}

404

if(debug){

405

fprintf_plus(stderr, "System clock is January 1970");

406

}

407

} else {

408

if(debug){

409

fprintf_plus(stderr, "System clock is invalid");

410

}

411

}

412

}

413

struct stat keystat;

414

ret = fstat(fd, &keystat);

415

if(ret != 0){

416

perror_plus("fstat");

417

break;

418

}

419

ret = raise_privileges();

420

if(ret != 0){

421

errno = ret;

422

perror_plus("Failed to raise privileges");

423

break;

424

}

425

if(debug){

426

fprintf_plus(stderr,

427

"Setting system clock to key file mtime");

428

}

429

if(clock_settime(CLOCK_REALTIME, &keystat.st_mtim) != 0){

430

perror_plus("clock_settime");

431

}

432

ret = lower_privileges();

433

if(ret != 0){

434

errno = ret;

435

perror_plus("Failed to lower privileges");

436

}

437

} while(false);

438

439

294

rc = gpgme_data_new_from_fd(&pgp_data, fd);

440

295

if(rc != GPG_ERR_NO_ERROR){

441

296

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

449

304

gpgme_strsource(rc), gpgme_strerror(rc));

450

305

return false;

451

306

}

452

{

453

gpgme_import_result_t import_result

454

= gpgme_op_import_result(mc->ctx);

455

if((import_result->imported < 1

456

or import_result->not_imported > 0)

457

and import_result->unchanged == 0){

458

fprintf_plus(stderr, "bad gpgme_op_import_results:\n");

459

fprintf_plus(stderr,

460

"The total number of considered keys: %d\n",

461

import_result->considered);

462

fprintf_plus(stderr,

463

"The number of keys without user ID: %d\n",

464

import_result->no_user_id);

465

fprintf_plus(stderr,

466

"The total number of imported keys: %d\n",

467

import_result->imported);

468

fprintf_plus(stderr, "The number of imported RSA keys: %d\n",

469

import_result->imported_rsa);

470

fprintf_plus(stderr, "The number of unchanged keys: %d\n",

471

import_result->unchanged);

472

fprintf_plus(stderr, "The number of new user IDs: %d\n",

473

import_result->new_user_ids);

474

fprintf_plus(stderr, "The number of new sub keys: %d\n",

475

import_result->new_sub_keys);

476

fprintf_plus(stderr, "The number of new signatures: %d\n",

477

import_result->new_signatures);

478

fprintf_plus(stderr, "The number of new revocations: %d\n",

479

import_result->new_revocations);

480

fprintf_plus(stderr,

481

"The total number of secret keys read: %d\n",

482

import_result->secret_read);

483

fprintf_plus(stderr,

484

"The number of imported secret keys: %d\n",

485

import_result->secret_imported);

486

fprintf_plus(stderr,

487

"The number of unchanged secret keys: %d\n",

488

import_result->secret_unchanged);

489

fprintf_plus(stderr, "The number of keys not imported: %d\n",

490

import_result->not_imported);

491

for(gpgme_import_status_t import_status

492

= import_result->imports;

493

import_status != NULL;

494

import_status = import_status->next){

495

fprintf_plus(stderr, "Import status for key: %s\n",

496

import_status->fpr);

497

if(import_status->result != GPG_ERR_NO_ERROR){

498

fprintf_plus(stderr, "Import result: %s: %s\n",

499

gpgme_strsource(import_status->result),

500

gpgme_strerror(import_status->result));

501

}

502

fprintf_plus(stderr, "Key status:\n");

503

fprintf_plus(stderr,

504

import_status->status & GPGME_IMPORT_NEW

505

? "The key was new.\n"

506

: "The key was not new.\n");

507

fprintf_plus(stderr,

508

import_status->status & GPGME_IMPORT_UID

509

? "The key contained new user IDs.\n"

510

: "The key did not contain new user IDs.\n");

511

fprintf_plus(stderr,

512

import_status->status & GPGME_IMPORT_SIG

513

? "The key contained new signatures.\n"

514

: "The key did not contain new signatures.\n");

515

fprintf_plus(stderr,

516

import_status->status & GPGME_IMPORT_SUBKEY

517

? "The key contained new sub keys.\n"

518

: "The key did not contain new sub keys.\n");

519

fprintf_plus(stderr,

520

import_status->status & GPGME_IMPORT_SECRET

521

? "The key contained a secret key.\n"

522

: "The key did not contain a secret key.\n");

523

}

524

return false;

525

}

526

}

527

307

528

ret = close(fd);

308

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

529

309

if(ret == -1){

530

310

perror_plus("close");

531

311

}

570

350

/* Create new GPGME "context" */

571

351

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

572

352

if(rc != GPG_ERR_NO_ERROR){

573

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

574

gpgme_strsource(rc), gpgme_strerror(rc));

353

fprintf_plus(stderr, "Mandos plugin mandos-client: "

354

"bad gpgme_new: %s: %s\n", gpgme_strsource(rc),

355

gpgme_strerror(rc));

575

356

return false;

576

357

}

577

358

613

394

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

614

395

rc = gpgme_data_new(&dh_plain);

615

396

if(rc != GPG_ERR_NO_ERROR){

616

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

397

fprintf_plus(stderr, "Mandos plugin mandos-client: "

398

"bad gpgme_data_new: %s: %s\n",

617

399

gpgme_strsource(rc), gpgme_strerror(rc));

618

400

gpgme_data_release(dh_crypto);

619

401

return -1;

632

414

if(result == NULL){

633

415

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

634

416

} else {

635

if(result->unsupported_algorithm != NULL) {

636

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

637

result->unsupported_algorithm);

638

}

639

fprintf_plus(stderr, "Wrong key usage: %s\n",

640

result->wrong_key_usage ? "Yes" : "No");

417

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

418

result->unsupported_algorithm);

419

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

420

result->wrong_key_usage);

641

421

if(result->file_name != NULL){

642

422

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

643

423

}

644

645

for(gpgme_recipient_t r = result->recipients; r != NULL;

646

r = r->next){

424

gpgme_recipient_t recipient;

425

recipient = result->recipients;

426

while(recipient != NULL){

647

427

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

648

gpgme_pubkey_algo_name(r->pubkey_algo));

649

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

428

gpgme_pubkey_algo_name

429

(recipient->pubkey_algo));

430

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

650

431

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

651

r->status == GPG_ERR_NO_SECKEY ? "No" : "Yes");

432

recipient->status == GPG_ERR_NO_SECKEY

433

? "No" : "Yes");

434

recipient = recipient->next;

652

435

}

653

436

}

654

437

}

710

493

return plaintext_length;

711

494

}

712

495

713

__attribute__((warn_unused_result, const))

714

static const char *safe_string(const char *str){

715

if(str == NULL)

716

return "(unknown)";

717

return str;

718

}

719

720

496

__attribute__((warn_unused_result))

721

497

static const char *safer_gnutls_strerror(int value){

722

498

const char *ret = gnutls_strerror(value);

723

return safe_string(ret);

499

if(ret == NULL)

500

ret = "(unknown)";

501

return ret;

724

502

}

725

503

726

504

/* GnuTLS log function callback */

730

508

fprintf_plus(stderr, "GnuTLS: %s", string);

731

509

}

732

510

733

__attribute__((nonnull(1, 2, 4), warn_unused_result))

511

__attribute__((nonnull, warn_unused_result))

734

512

static int init_gnutls_global(const char *pubkeyfilename,

735

513

const char *seckeyfilename,

736

const char *dhparamsfilename,

737

514

mandos_context *mc){

738

515

int ret;

739

516

741

518

fprintf_plus(stderr, "Initializing GnuTLS\n");

742

519

}

743

520

521

ret = gnutls_global_init();

522

if(ret != GNUTLS_E_SUCCESS){

523

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

524

safer_gnutls_strerror(ret));

525

return -1;

526

}

527

744

528

if(debug){

745

529

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

746

530

* - GnuTLS manual

754

538

if(ret != GNUTLS_E_SUCCESS){

755

539

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

756

540

safer_gnutls_strerror(ret));

541

gnutls_global_deinit();

757

542

return -1;

758

543

}

759

544

760

545

if(debug){

761

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

762

" private key %s as GnuTLS credentials\n",

546

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

547

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

763

548

pubkeyfilename,

764

549

seckeyfilename);

765

550

}

766

551

767

#if GNUTLS_VERSION_NUMBER >= 0x030606

768

ret = gnutls_certificate_set_rawpk_key_file

769

(mc->cred, pubkeyfilename, seckeyfilename,

770

GNUTLS_X509_FMT_PEM, /* format */

771

NULL, /* pass */

772

/* key_usage */

773

GNUTLS_KEY_DIGITAL_SIGNATURE | GNUTLS_KEY_KEY_ENCIPHERMENT,

774

NULL, /* names */

775

0, /* names_length */

776

/* privkey_flags */

777

GNUTLS_PKCS_PLAIN | GNUTLS_PKCS_NULL_PASSWORD,

778

0); /* pkcs11_flags */

779

#elif GNUTLS_VERSION_NUMBER < 0x030600

780

552

ret = gnutls_certificate_set_openpgp_key_file

781

553

(mc->cred, pubkeyfilename, seckeyfilename,

782

554

GNUTLS_OPENPGP_FMT_BASE64);

783

#else

784

#error "Needs GnuTLS 3.6.6 or later, or before 3.6.0"

785

#endif

786

555

if(ret != GNUTLS_E_SUCCESS){

787

556

fprintf_plus(stderr,

788

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

557

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

789

558

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

790

559

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

791

560

safer_gnutls_strerror(ret));

800

569

safer_gnutls_strerror(ret));

801

570

goto globalfail;

802

571

}

803

/* If a Diffie-Hellman parameters file was given, try to use it */

804

if(dhparamsfilename != NULL){

805

gnutls_datum_t params = { .data = NULL, .size = 0 };

806

do {

807

int dhpfile = open(dhparamsfilename, O_RDONLY);

808

if(dhpfile == -1){

809

perror_plus("open");

810

dhparamsfilename = NULL;

811

break;

812

}

813

size_t params_capacity = 0;

814

while(true){

815

params_capacity = incbuffer((char **)&params.data,

816

(size_t)params.size,

817

(size_t)params_capacity);

818

if(params_capacity == 0){

819

perror_plus("incbuffer");

820

free(params.data);

821

params.data = NULL;

822

dhparamsfilename = NULL;

823

break;

824

}

825

ssize_t bytes_read = read(dhpfile,

826

params.data + params.size,

827

BUFFER_SIZE);

828

/* EOF */

829

if(bytes_read == 0){

830

break;

831

}

832

/* check bytes_read for failure */

833

if(bytes_read < 0){

834

perror_plus("read");

835

free(params.data);

836

params.data = NULL;

837

dhparamsfilename = NULL;

838

break;

839

}

840

params.size += (unsigned int)bytes_read;

841

}

842

ret = close(dhpfile);

843

if(ret == -1){

844

perror_plus("close");

845

}

846

if(params.data == NULL){

847

dhparamsfilename = NULL;

848

}

849

if(dhparamsfilename == NULL){

850

break;

851

}

852

ret = gnutls_dh_params_import_pkcs3(mc->dh_params, &params,

853

GNUTLS_X509_FMT_PEM);

854

if(ret != GNUTLS_E_SUCCESS){

855

fprintf_plus(stderr, "Failed to parse DH parameters in file"

856

" \"%s\": %s\n", dhparamsfilename,

857

safer_gnutls_strerror(ret));

858

dhparamsfilename = NULL;

859

}

860

free(params.data);

861

} while(false);

862

}

863

if(dhparamsfilename == NULL){

864

if(mc->dh_bits == 0){

865

#if GNUTLS_VERSION_NUMBER < 0x030600

866

/* Find out the optimal number of DH bits */

867

/* Try to read the private key file */

868

gnutls_datum_t buffer = { .data = NULL, .size = 0 };

869

do {

870

int secfile = open(seckeyfilename, O_RDONLY);

871

if(secfile == -1){

872

perror_plus("open");

873

break;

874

}

875

size_t buffer_capacity = 0;

876

while(true){

877

buffer_capacity = incbuffer((char **)&buffer.data,

878

(size_t)buffer.size,

879

(size_t)buffer_capacity);

880

if(buffer_capacity == 0){

881

perror_plus("incbuffer");

882

free(buffer.data);

883

buffer.data = NULL;

884

break;

885

}

886

ssize_t bytes_read = read(secfile,

887

buffer.data + buffer.size,

888

BUFFER_SIZE);

889

/* EOF */

890

if(bytes_read == 0){

891

break;

892

}

893

/* check bytes_read for failure */

894

if(bytes_read < 0){

895

perror_plus("read");

896

free(buffer.data);

897

buffer.data = NULL;

898

break;

899

}

900

buffer.size += (unsigned int)bytes_read;

901

}

902

close(secfile);

903

} while(false);

904

/* If successful, use buffer to parse private key */

905

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

906

if(buffer.data != NULL){

907

{

908

gnutls_openpgp_privkey_t privkey = NULL;

909

ret = gnutls_openpgp_privkey_init(&privkey);

910

if(ret != GNUTLS_E_SUCCESS){

911

fprintf_plus(stderr, "Error initializing OpenPGP key"

912

" structure: %s",

913

safer_gnutls_strerror(ret));

914

free(buffer.data);

915

buffer.data = NULL;

916

} else {

917

ret = gnutls_openpgp_privkey_import

918

(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);

919

if(ret != GNUTLS_E_SUCCESS){

920

fprintf_plus(stderr, "Error importing OpenPGP key : %s",

921

safer_gnutls_strerror(ret));

922

privkey = NULL;

923

}

924

free(buffer.data);

925

buffer.data = NULL;

926

if(privkey != NULL){

927

/* Use private key to suggest an appropriate

928

sec_param */

929

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

930

gnutls_openpgp_privkey_deinit(privkey);

931

if(debug){

932

fprintf_plus(stderr, "This OpenPGP key implies using"

933

" a GnuTLS security parameter \"%s\".\n",

934

safe_string(gnutls_sec_param_get_name

935

(sec_param)));

936

}

937

}

938

}

939

}

940

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

941

/* Err on the side of caution */

942

sec_param = GNUTLS_SEC_PARAM_ULTRA;

943

if(debug){

944

fprintf_plus(stderr, "Falling back to security parameter"

945

" \"%s\"\n",

946

safe_string(gnutls_sec_param_get_name

947

(sec_param)));

948

}

949

}

950

}

951

unsigned int uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

952

if(uret != 0){

953

mc->dh_bits = uret;

954

if(debug){

955

fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"

956

" implies %u DH bits; using that.\n",

957

safe_string(gnutls_sec_param_get_name

958

(sec_param)),

959

mc->dh_bits);

960

}

961

} else {

962

fprintf_plus(stderr, "Failed to get implied number of DH"

963

" bits for security parameter \"%s\"): %s\n",

964

safe_string(gnutls_sec_param_get_name

965

(sec_param)),

966

safer_gnutls_strerror(ret));

967

goto globalfail;

968

}

969

#endif

970

} else { /* dh_bits != 0 */

971

if(debug){

972

fprintf_plus(stderr, "DH bits explicitly set to %u\n",

973

mc->dh_bits);

974

}

975

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

976

if(ret != GNUTLS_E_SUCCESS){

977

fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"

978

" bits): %s\n", mc->dh_bits,

979

safer_gnutls_strerror(ret));

980

goto globalfail;

981

}

982

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

983

}

984

}

572

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

573

if(ret != GNUTLS_E_SUCCESS){

574

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

575

safer_gnutls_strerror(ret));

576

goto globalfail;

577

}

578

579

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

985

580

986

581

return 0;

987

582

988

583

globalfail:

989

584

990

585

gnutls_certificate_free_credentials(mc->cred);

586

gnutls_global_deinit();

991

587

gnutls_dh_params_deinit(mc->dh_params);

992

588

return -1;

993

589

}

998

594

int ret;

999

595

/* GnuTLS session creation */

1000

596

do {

1001

ret = gnutls_init(session, (GNUTLS_SERVER

1002

#if GNUTLS_VERSION_NUMBER >= 0x030506

1003

| GNUTLS_NO_TICKETS

1004

#endif

1005

#if GNUTLS_VERSION_NUMBER >= 0x030606

1006

| GNUTLS_ENABLE_RAWPK

1007

#endif

1008

));

597

ret = gnutls_init(session, GNUTLS_SERVER);

1009

598

if(quit_now){

1010

599

return -1;

1011

600

}

1052

641

/* ignore client certificate if any. */

1053

642

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

1054

643

644

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

645

1055

646

return 0;

1056

647

}

1057

648

1059

650

static void empty_log(__attribute__((unused)) AvahiLogLevel level,

1060

651

__attribute__((unused)) const char *txt){}

1061

652

1062

/* Helper function to add_local_route() and delete_local_route() */

1063

__attribute__((nonnull, warn_unused_result))

1064

static bool add_delete_local_route(const bool add,

1065

const char *address,

1066

AvahiIfIndex if_index){

1067

int ret;

1068

char helper[] = "mandos-client-iprouteadddel";

1069

char add_arg[] = "add";

1070

char delete_arg[] = "delete";

1071

char debug_flag[] = "--debug";

1072

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

1073

if(pluginhelperdir == NULL){

1074

if(debug){

1075

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

1076

" variable not set; cannot run helper\n");

1077

}

1078

return false;

1079

}

1080

1081

char interface[IF_NAMESIZE];

1082

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

1083

perror_plus("if_indextoname");

1084

return false;

1085

}

1086

1087

int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));

1088

if(devnull == -1){

1089

perror_plus("open(\"/dev/null\", O_RDONLY)");

1090

return false;

1091

}

1092

pid_t pid = fork();

1093

if(pid == 0){

1094

/* Child */

1095

/* Raise privileges */

1096

errno = raise_privileges_permanently();

1097

if(errno != 0){

1098

perror_plus("Failed to raise privileges");

1099

/* _exit(EX_NOPERM); */

1100

} else {

1101

/* Set group */

1102

errno = 0;

1103

ret = setgid(0);

1104

if(ret == -1){

1105

perror_plus("setgid");

1106

close(devnull);

1107

_exit(EX_NOPERM);

1108

}

1109

/* Reset supplementary groups */

1110

errno = 0;

1111

ret = setgroups(0, NULL);

1112

if(ret == -1){

1113

perror_plus("setgroups");

1114

close(devnull);

1115

_exit(EX_NOPERM);

1116

}

1117

}

1118

ret = dup2(devnull, STDIN_FILENO);

1119

if(ret == -1){

1120

perror_plus("dup2(devnull, STDIN_FILENO)");

1121

close(devnull);

1122

_exit(EX_OSERR);

1123

}

1124

ret = close(devnull);

1125

if(ret == -1){

1126

perror_plus("close");

1127

}

1128

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1129

if(ret == -1){

1130

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

1131

_exit(EX_OSERR);

1132

}

1133

int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,

1134

O_RDONLY

1135

| O_DIRECTORY

1136

| O_PATH

1137

| O_CLOEXEC));

1138

if(helperdir_fd == -1){

1139

perror_plus("open");

1140

_exit(EX_UNAVAILABLE);

1141

}

1142

int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,

1143

helper, O_RDONLY));

1144

if(helper_fd == -1){

1145

perror_plus("openat");

1146

close(helperdir_fd);

1147

_exit(EX_UNAVAILABLE);

1148

}

1149

close(helperdir_fd);

1150

#ifdef __GNUC__

1151

#pragma GCC diagnostic push

1152

#pragma GCC diagnostic ignored "-Wcast-qual"

1153

#endif

1154

if(fexecve(helper_fd, (char *const [])

1155

{ helper, add ? add_arg : delete_arg, (char *)address,

1156

interface, debug ? debug_flag : NULL, NULL },

1157

environ) == -1){

1158

#ifdef __GNUC__

1159

#pragma GCC diagnostic pop

1160

#endif

1161

perror_plus("fexecve");

1162

_exit(EXIT_FAILURE);

1163

}

1164

}

1165

if(pid == -1){

1166

perror_plus("fork");

1167

close(devnull);

1168

return false;

1169

}

1170

ret = close(devnull);

1171

if(ret == -1){

1172

perror_plus("close");

1173

}

1174

int status;

1175

pid_t pret = -1;

1176

errno = 0;

1177

do {

1178

pret = waitpid(pid, &status, 0);

1179

if(pret == -1 and errno == EINTR and quit_now){

1180

int errno_raising = 0;

1181

if((errno = raise_privileges()) != 0){

1182

errno_raising = errno;

1183

perror_plus("Failed to raise privileges in order to"

1184

" kill helper program");

1185

}

1186

if(kill(pid, SIGTERM) == -1){

1187

perror_plus("kill");

1188

}

1189

if((errno_raising == 0) and (errno = lower_privileges()) != 0){

1190

perror_plus("Failed to lower privileges after killing"

1191

" helper program");

1192

}

1193

return false;

1194

}

1195

} while(pret == -1 and errno == EINTR);

1196

if(pret == -1){

1197

perror_plus("waitpid");

1198

return false;

1199

}

1200

if(WIFEXITED(status)){

1201

if(WEXITSTATUS(status) != 0){

1202

fprintf_plus(stderr, "Error: iprouteadddel exited"

1203

" with status %d\n", WEXITSTATUS(status));

1204

return false;

1205

}

1206

return true;

1207

}

1208

if(WIFSIGNALED(status)){

1209

fprintf_plus(stderr, "Error: iprouteadddel died by"

1210

" signal %d\n", WTERMSIG(status));

1211

return false;

1212

}

1213

fprintf_plus(stderr, "Error: iprouteadddel crashed\n");

1214

return false;

1215

}

1216

1217

__attribute__((nonnull, warn_unused_result))

1218

static bool add_local_route(const char *address,

1219

AvahiIfIndex if_index){

1220

if(debug){

1221

fprintf_plus(stderr, "Adding route to %s\n", address);

1222

}

1223

return add_delete_local_route(true, address, if_index);

1224

}

1225

1226

__attribute__((nonnull, warn_unused_result))

1227

static bool delete_local_route(const char *address,

1228

AvahiIfIndex if_index){

1229

if(debug){

1230

fprintf_plus(stderr, "Removing route to %s\n", address);

1231

}

1232

return add_delete_local_route(false, address, if_index);

1233

}

1234

1235

653

/* Called when a Mandos server is found */

1236

654

__attribute__((nonnull, warn_unused_result))

1237

655

static int start_mandos_communication(const char *ip, in_port_t port,

1248

666

int retval = -1;

1249

667

gnutls_session_t session;

1250

668

int pf; /* Protocol family */

1251

bool route_added = false;

1252

669

1253

670

errno = 0;

1254

671

1276

693

bool match = false;

1277

694

{

1278

695

char *interface = NULL;

1279

while((interface = argz_next(mc->interfaces,

1280

mc->interfaces_size,

1281

interface))){

696

while((interface=argz_next(mc->interfaces, mc->interfaces_size,

697

interface))){

1282

698

if(if_nametoindex(interface) == (unsigned int)if_index){

1283

699

match = true;

1284

700

break;

1313

729

PRIuMAX "\n", ip, (uintmax_t)port);

1314

730

}

1315

731

1316

tcp_sd = socket(pf, SOCK_STREAM | SOCK_CLOEXEC, 0);

732

tcp_sd = socket(pf, SOCK_STREAM, 0);

1317

733

if(tcp_sd < 0){

1318

734

int e = errno;

1319

735

perror_plus("socket");

1326

742

goto mandos_end;

1327

743

}

1328

744

745

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

1329

746

if(af == AF_INET6){

1330

struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;

1331

*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };

1332

ret = inet_pton(af, ip, &to6->sin6_addr);

747

((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;

748

ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);

1333

749

} else { /* IPv4 */

1334

struct sockaddr_in *to4 = (struct sockaddr_in *)&to;

1335

*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };

1336

ret = inet_pton(af, ip, &to4->sin_addr);

750

((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;

751

ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);

1337

752

}

1338

753

if(ret < 0 ){

1339

754

int e = errno;

1409

824

goto mandos_end;

1410

825

}

1411

826

1412

while(true){

1413

if(af == AF_INET6){

1414

ret = connect(tcp_sd, (struct sockaddr *)&to,

1415

sizeof(struct sockaddr_in6));

1416

} else {

1417

ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */

1418

sizeof(struct sockaddr_in));

1419

}

1420

if(ret < 0){

1421

if(((errno == ENETUNREACH) or (errno == EHOSTUNREACH))

1422

and if_index != AVAHI_IF_UNSPEC

1423

and connect_to == NULL

1424

and not route_added and

1425

((af == AF_INET6 and not

1426

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1427

&to)->sin6_addr)))

1428

or (af == AF_INET and

1429

/* Not a a IPv4LL address */

1430

(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)

1431

& 0xFFFF0000L) != 0xA9FE0000L))){

1432

/* Work around Avahi bug - Avahi does not announce link-local

1433

addresses if it has a global address, so local hosts with

1434

*only* a link-local address (e.g. Mandos clients) cannot

1435

connect to a Mandos server announced by Avahi on a server

1436

host with a global address. Work around this by retrying

1437

with an explicit route added with the server's address.

1438

1439

Avahi bug reference:

1440

https://lists.freedesktop.org/archives/avahi/2010-February/001833.html

1441

https://bugs.debian.org/587961

1442

*/

1443

if(debug){

1444

fprintf_plus(stderr, "Mandos server unreachable, trying"

1445

" direct route\n");

1446

}

1447

int e = errno;

1448

route_added = add_local_route(ip, if_index);

1449

if(route_added){

1450

continue;

1451

}

1452

errno = e;

1453

}

1454

if(errno != ECONNREFUSED or debug){

1455

int e = errno;

1456

perror_plus("connect");

1457

errno = e;

1458

}

1459

goto mandos_end;

1460

}

1461

1462

if(quit_now){

1463

errno = EINTR;

1464

goto mandos_end;

1465

}

1466

break;

827

if(af == AF_INET6){

828

ret = connect(tcp_sd, (struct sockaddr *)&to,

829

sizeof(struct sockaddr_in6));

830

} else {

831

ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */

832

sizeof(struct sockaddr_in));

833

}

834

if(ret < 0){

835

if((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){

836

int e = errno;

837

perror_plus("connect");

838

errno = e;

839

}

840

goto mandos_end;

841

}

842

843

if(quit_now){

844

errno = EINTR;

845

goto mandos_end;

1467

846

}

1468

847

1469

848

const char *out = mandos_protocol_version;

1623

1002

&decrypted_buffer, mc);

1624

1003

if(decrypted_buffer_size >= 0){

1625

1004

1626

clearerr(stdout);

1627

1005

written = 0;

1628

1006

while(written < (size_t) decrypted_buffer_size){

1629

1007

if(quit_now){

1645

1023

}

1646

1024

written += (size_t)ret;

1647

1025

}

1648

ret = fflush(stdout);

1649

if(ret != 0){

1650

int e = errno;

1651

if(debug){

1652

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

1653

strerror(errno));

1654

}

1655

errno = e;

1656

goto mandos_end;

1657

}

1658

1026

retval = 0;

1659

1027

}

1660

1028

}

1663

1031

1664

1032

mandos_end:

1665

1033

{

1666

if(route_added){

1667

if(not delete_local_route(ip, if_index)){

1668

fprintf_plus(stderr, "Failed to delete local route to %s on"

1669

" interface %d", ip, if_index);

1670

}

1671

}

1672

1034

int e = errno;

1673

1035

free(decrypted_buffer);

1674

1036

free(buffer);

1675

1037

if(tcp_sd >= 0){

1676

ret = close(tcp_sd);

1038

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

1677

1039

}

1678

1040

if(ret == -1){

1679

1041

if(e == 0){

1691

1053

return retval;

1692

1054

}

1693

1055

1056

__attribute__((nonnull))

1694

1057

static void resolve_callback(AvahiSServiceResolver *r,

1695

1058

AvahiIfIndex interface,

1696

1059

AvahiProtocol proto,

1833

1196

__attribute__((nonnull, warn_unused_result))

1834

1197

bool get_flags(const char *ifname, struct ifreq *ifr){

1835

1198

int ret;

1836

int old_errno;

1199

error_t ret_errno;

1837

1200

1838

1201

int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1839

1202

if(s < 0){

1840

old_errno = errno;

1203

ret_errno = errno;

1841

1204

perror_plus("socket");

1842

errno = old_errno;

1205

errno = ret_errno;

1843

1206

return false;

1844

1207

}

1845

strncpy(ifr->ifr_name, ifname, IF_NAMESIZE);

1846

ifr->ifr_name[IF_NAMESIZE-1] = '\0'; /* NUL terminate */

1208

strcpy(ifr->ifr_name, ifname);

1847

1209

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1848

1210

if(ret == -1){

1849

1211

if(debug){

1850

old_errno = errno;

1212

ret_errno = errno;

1851

1213

perror_plus("ioctl SIOCGIFFLAGS");

1852

errno = old_errno;

1853

}

1854

if((close(s) == -1) and debug){

1855

old_errno = errno;

1856

perror_plus("close");

1857

errno = old_errno;

1214

errno = ret_errno;

1858

1215

}

1859

1216

return false;

1860

1217

}

1861

if((close(s) == -1) and debug){

1862

old_errno = errno;

1863

perror_plus("close");

1864

errno = old_errno;

1865

}

1866

1218

return true;

1867

1219

}

1868

1220

2110

1462

}

2111

1463

}

2112

1464

1465

/* Set effective uid to 0, return errno */

1466

__attribute__((warn_unused_result))

1467

error_t raise_privileges(void){

1468

error_t old_errno = errno;

1469

error_t ret_errno = 0;

1470

if(seteuid(0) == -1){

1471

ret_errno = errno;

1472

}

1473

errno = old_errno;

1474

return ret_errno;

1475

}

1476

1477

/* Set effective and real user ID to 0. Return errno. */

1478

__attribute__((warn_unused_result))

1479

error_t raise_privileges_permanently(void){

1480

error_t old_errno = errno;

1481

error_t ret_errno = raise_privileges();

1482

if(ret_errno != 0){

1483

errno = old_errno;

1484

return ret_errno;

1485

}

1486

if(setuid(0) == -1){

1487

ret_errno = errno;

1488

}

1489

errno = old_errno;

1490

return ret_errno;

1491

}

1492

1493

/* Set effective user ID to unprivileged saved user ID */

1494

__attribute__((warn_unused_result))

1495

error_t lower_privileges(void){

1496

error_t old_errno = errno;

1497

error_t ret_errno = 0;

1498

if(seteuid(uid) == -1){

1499

ret_errno = errno;

1500

}

1501

errno = old_errno;

1502

return ret_errno;

1503

}

1504

1505

/* Lower privileges permanently */

1506

__attribute__((warn_unused_result))

1507

error_t lower_privileges_permanently(void){

1508

error_t old_errno = errno;

1509

error_t ret_errno = 0;

1510

if(setuid(uid) == -1){

1511

ret_errno = errno;

1512

}

1513

errno = old_errno;

1514

return ret_errno;

1515

}

1516

2113

1517

__attribute__((nonnull))

2114

1518

void run_network_hooks(const char *mode, const char *interface,

2115

1519

const float delay){

2116

1520

struct dirent **direntries = NULL;

2117

1521

if(hookdir_fd == -1){

2118

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

2119

| O_CLOEXEC);

1522

hookdir_fd = open(hookdir, O_RDONLY);

2120

1523

if(hookdir_fd == -1){

2121

1524

if(errno == ENOENT){

2122

1525

if(debug){

2129

1532

return;

2130

1533

}

2131

1534

}

2132

int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));

2133

if(devnull == -1){

2134

perror_plus("open(\"/dev/null\", O_RDONLY)");

2135

return;

2136

}

1535

#ifdef __GLIBC__

1536

#if __GLIBC_PREREQ(2, 15)

2137

1537

int numhooks = scandirat(hookdir_fd, ".", &direntries,

2138

1538

runnable_hook, alphasort);

1539

#else /* not __GLIBC_PREREQ(2, 15) */

1540

int numhooks = scandir(hookdir, &direntries, runnable_hook,

1541

alphasort);

1542

#endif /* not __GLIBC_PREREQ(2, 15) */

1543

#else /* not __GLIBC__ */

1544

int numhooks = scandir(hookdir, &direntries, runnable_hook,

1545

alphasort);

1546

#endif /* not __GLIBC__ */

2139

1547

if(numhooks == -1){

2140

1548

perror_plus("scandir");

2141

close(devnull);

2142

1549

return;

2143

1550

}

2144

1551

struct dirent *direntry;

2145

1552

int ret;

1553

int devnull = open("/dev/null", O_RDONLY);

2146

1554

for(int i = 0; i < numhooks; i++){

2147

1555

direntry = direntries[i];

2148

1556

if(debug){

2172

1580

perror_plus("setgroups");

2173

1581

_exit(EX_NOPERM);

2174

1582

}

1583

ret = dup2(devnull, STDIN_FILENO);

1584

if(ret == -1){

1585

perror_plus("dup2(devnull, STDIN_FILENO)");

1586

_exit(EX_OSERR);

1587

}

1588

ret = close(devnull);

1589

if(ret == -1){

1590

perror_plus("close");

1591

_exit(EX_OSERR);

1592

}

1593

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1594

if(ret == -1){

1595

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

1596

_exit(EX_OSERR);

1597

}

2175

1598

ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);

2176

1599

if(ret == -1){

2177

1600

perror_plus("setenv");

2212

1635

_exit(EX_OSERR);

2213

1636

}

2214

1637

}

2215

int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,

2216

direntry->d_name,

2217

O_RDONLY));

1638

int hook_fd = openat(hookdir_fd, direntry->d_name, O_RDONLY);

2218

1639

if(hook_fd == -1){

2219

1640

perror_plus("openat");

2220

1641

_exit(EXIT_FAILURE);

2221

1642

}

2222

if(close(hookdir_fd) == -1){

1643

if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){

2223

1644

perror_plus("close");

2224

1645

_exit(EXIT_FAILURE);

2225

1646

}

2226

ret = dup2(devnull, STDIN_FILENO);

2227

if(ret == -1){

2228

perror_plus("dup2(devnull, STDIN_FILENO)");

2229

_exit(EX_OSERR);

2230

}

2231

ret = close(devnull);

2232

if(ret == -1){

2233

perror_plus("close");

2234

_exit(EX_OSERR);

2235

}

2236

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2237

if(ret == -1){

2238

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

2239

_exit(EX_OSERR);

2240

}

2241

1647

if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },

2242

1648

environ) == -1){

2243

1649

perror_plus("fexecve");

2244

1650

_exit(EXIT_FAILURE);

2245

1651

}

2246

1652

} else {

2247

if(hook_pid == -1){

2248

perror_plus("fork");

2249

free(direntry);

2250

continue;

2251

}

2252

1653

int status;

2253

1654

if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){

2254

1655

perror_plus("waitpid");

2283

1684

free(direntry);

2284

1685

}

2285

1686

free(direntries);

2286

if(close(hookdir_fd) == -1){

1687

if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){

2287

1688

perror_plus("close");

2288

1689

} else {

2289

1690

hookdir_fd = -1;

2292

1693

}

2293

1694

2294

1695

__attribute__((nonnull, warn_unused_result))

2295

int bring_up_interface(const char *const interface,

2296

const float delay){

2297

int old_errno = errno;

1696

error_t bring_up_interface(const char *const interface,

1697

const float delay){

1698

error_t old_errno = errno;

2298

1699

int ret;

2299

1700

struct ifreq network;

2300

1701

unsigned int if_index = if_nametoindex(interface);

2310

1711

}

2311

1712

2312

1713

if(not interface_is_up(interface)){

2313

int ret_errno = 0;

2314

int ioctl_errno = 0;

1714

error_t ret_errno = 0, ioctl_errno = 0;

2315

1715

if(not get_flags(interface, &network)){

2316

1716

ret_errno = errno;

2317

1717

fprintf_plus(stderr, "Failed to get flags for interface "

2330

1730

}

2331

1731

2332

1732

if(quit_now){

2333

ret = close(sd);

1733

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

2334

1734

if(ret == -1){

2335

1735

perror_plus("close");

2336

1736

}

2386

1786

}

2387

1787

2388

1788

/* Close the socket */

2389

ret = close(sd);

1789

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

2390

1790

if(ret == -1){

2391

1791

perror_plus("close");

2392

1792

}

2404

1804

2405

1805

/* Sleep checking until interface is running.

2406

1806

Check every 0.25s, up to total time of delay */

2407

for(int i = 0; i < delay * 4; i++){

1807

for(int i=0; i < delay * 4; i++){

2408

1808

if(interface_is_running(interface)){

2409

1809

break;

2410

1810

}

2420

1820

}

2421

1821

2422

1822

__attribute__((nonnull, warn_unused_result))

2423

int take_down_interface(const char *const interface){

2424

int old_errno = errno;

1823

error_t take_down_interface(const char *const interface){

1824

error_t old_errno = errno;

2425

1825

struct ifreq network;

2426

1826

unsigned int if_index = if_nametoindex(interface);

2427

1827

if(if_index == 0){

2430

1830

return ENXIO;

2431

1831

}

2432

1832

if(interface_is_up(interface)){

2433

int ret_errno = 0;

2434

int ioctl_errno = 0;

1833

error_t ret_errno = 0, ioctl_errno = 0;

2435

1834

if(not get_flags(interface, &network) and debug){

2436

1835

ret_errno = errno;

2437

1836

fprintf_plus(stderr, "Failed to get flags for interface "

2475

1874

}

2476

1875

2477

1876

/* Close the socket */

2478

int ret = close(sd);

1877

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

2479

1878

if(ret == -1){

2480

1879

perror_plus("close");

2481

1880

}

2496

1895

}

2497

1896

2498

1897

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

2499

mandos_context mc = { .server = NULL, .dh_bits = 0,

2500

#if GNUTLS_VERSION_NUMBER >= 0x030606

2501

.priority = "SECURE128:!CTYPE-X.509"

2502

":+CTYPE-RAWPK:!RSA:!VERS-ALL:+VERS-TLS1.3"

2503

":%PROFILE_ULTRA",

2504

#elif GNUTLS_VERSION_NUMBER < 0x030600

2505

.priority = "SECURE256:!CTYPE-X.509"

2506

":+CTYPE-OPENPGP:!RSA:+SIGN-DSA-SHA256",

2507

#else

2508

#error "Needs GnuTLS 3.6.6 or later, or before 3.6.0"

2509

#endif

2510

.current_server = NULL, .interfaces = NULL,

2511

.interfaces_size = 0 };

1898

mandos_context mc = { .server = NULL, .dh_bits = 1024,

1899

.priority = "SECURE256:!CTYPE-X.509:"

1900

"+CTYPE-OPENPGP", .current_server = NULL,

1901

.interfaces = NULL, .interfaces_size = 0 };

2512

1902

AvahiSServiceBrowser *sb = NULL;

2513

1903

error_t ret_errno;

2514

1904

int ret;

2523

1913

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2524

1914

const char *seckey = PATHDIR "/" SECKEY;

2525

1915

const char *pubkey = PATHDIR "/" PUBKEY;

2526

#if GNUTLS_VERSION_NUMBER >= 0x030606

2527

const char *tls_privkey = PATHDIR "/" TLS_PRIVKEY;

2528

const char *tls_pubkey = PATHDIR "/" TLS_PUBKEY;

2529

#endif

2530

const char *dh_params_file = NULL;

2531

1916

char *interfaces_hooks = NULL;

2532

1917

2533

1918

bool gnutls_initialized = false;

2580

1965

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

2581

1966

.arg = "FILE",

2582

1967

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

2583

.group = 1 },

2584

{ .name = "tls-privkey", .key = 't',

2585

.arg = "FILE",

2586

#if GNUTLS_VERSION_NUMBER >= 0x030606

2587

.doc = "TLS private key file base name",

2588

#else

2589

.doc = "Dummy; ignored (requires GnuTLS 3.6.6)",

2590

#endif

2591

.group = 1 },

2592

{ .name = "tls-pubkey", .key = 'T',

2593

.arg = "FILE",

2594

#if GNUTLS_VERSION_NUMBER >= 0x030606

2595

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

2596

#else

2597

.doc = "Dummy; ignored (requires GnuTLS 3.6.6)",

2598

#endif

2599

.group = 1 },

1968

.group = 2 },

2600

1969

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

2601

1970

.arg = "BITS",

2602

1971

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

2603

1972

" Diffie-Hellman key exchange",

2604

1973

.group = 2 },

2605

{ .name = "dh-params", .key = 134,

2606

.arg = "FILE",

2607

.doc = "PEM-encoded PKCS#3 file with pre-generated parameters"

2608

" for the Diffie-Hellman key exchange",

2609

.group = 2 },

2610

1974

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

2611

1975

.arg = "STRING",

2612

1976

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

2658

2022

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

2659

2023

pubkey = arg;

2660

2024

break;

2661

case 't': /* --tls-privkey */

2662

#if GNUTLS_VERSION_NUMBER >= 0x030606

2663

tls_privkey = arg;

2664

#endif

2665

break;

2666

case 'T': /* --tls-pubkey */

2667

#if GNUTLS_VERSION_NUMBER >= 0x030606

2668

tls_pubkey = arg;

2669

#endif

2670

break;

2671

2025

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

2672

2026

errno = 0;

2673

2027

tmpmax = strtoimax(arg, &tmp, 10);

2677

2031

}

2678

2032

mc.dh_bits = (typeof(mc.dh_bits))tmpmax;

2679

2033

break;

2680

case 134: /* --dh-params */

2681

dh_params_file = arg;

2682

break;

2683

2034

case 130: /* --priority */

2684

2035

mc.priority = arg;

2685

2036

break;

2708

2059

argp_state_help(state, state->out_stream,

2709

2060

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

2710

2061

& ~(unsigned int)ARGP_HELP_EXIT_OK);

2711

__builtin_unreachable();

2712

2062

case -3: /* --usage */

2713

2063

argp_state_help(state, state->out_stream,

2714

2064

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

2715

__builtin_unreachable();

2716

2065

case 'V': /* --version */

2717

2066

fprintf_plus(state->out_stream, "%s\n", argp_program_version);

2718

2067

exit(argp_err_exit_status);

2727

2076

.args_doc = "",

2728

2077

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

2729

2078

" passwords from a Mandos server" };

2730

ret_errno = argp_parse(&argp, argc, argv,

2731

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2732

switch(ret_errno){

2079

ret = argp_parse(&argp, argc, argv,

2080

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2081

switch(ret){

2733

2082

case 0:

2734

2083

break;

2735

2084

case ENOMEM:

2736

2085

default:

2737

errno = ret_errno;

2086

errno = ret;

2738

2087

perror_plus("argp_parse");

2739

2088

exitcode = EX_OSERR;

2740

2089

goto end;

2743

2092

goto end;

2744

2093

}

2745

2094

}

2746

2095

2747

2096

{

2097

/* Work around Debian bug #633582:

2098

<http://bugs.debian.org/633582> */

2099

2748

2100

/* Re-raise privileges */

2749

ret = raise_privileges();

2750

if(ret != 0){

2751

errno = ret;

2101

ret_errno = raise_privileges();

2102

if(ret_errno != 0){

2103

errno = ret_errno;

2752

2104

perror_plus("Failed to raise privileges");

2753

2105

} else {

2754

2106

struct stat st;

2755

2107

2756

/* Work around Debian bug #633582:

2757

<https://bugs.debian.org/633582> */

2758

2759

2108

if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){

2760

2109

int seckey_fd = open(seckey, O_RDONLY);

2761

2110

if(seckey_fd == -1){

2773

2122

}

2774

2123

}

2775

2124

}

2776

close(seckey_fd);

2125

TEMP_FAILURE_RETRY(close(seckey_fd));

2777

2126

}

2778

2127

}

2779

2128

2780

2129

if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){

2781

2130

int pubkey_fd = open(pubkey, O_RDONLY);

2782

2131

if(pubkey_fd == -1){

2794

2143

}

2795

2144

}

2796

2145

}

2797

close(pubkey_fd);

2798

}

2799

}

2800

2801

if(dh_params_file != NULL

2802

and strcmp(dh_params_file, PATHDIR "/dhparams.pem" ) == 0){

2803

int dhparams_fd = open(dh_params_file, O_RDONLY);

2804

if(dhparams_fd == -1){

2805

perror_plus("open");

2806

} else {

2807

ret = (int)TEMP_FAILURE_RETRY(fstat(dhparams_fd, &st));

2808

if(ret == -1){

2809

perror_plus("fstat");

2810

} else {

2811

if(S_ISREG(st.st_mode)

2812

and st.st_uid == 0 and st.st_gid == 0){

2813

ret = fchown(dhparams_fd, uid, gid);

2814

if(ret == -1){

2815

perror_plus("fchown");

2816

}

2817

}

2818

}

2819

close(dhparams_fd);

2820

}

2821

}

2822

2823

/* Work around Debian bug #981302

2824

<https://bugs.debian.org/981302> */

2825

if(lstat("/dev/fd", &st) != 0 and errno == ENOENT){

2826

ret = symlink("/proc/self/fd", "/dev/fd");

2827

if(ret == -1){

2828

perror_plus("Failed to create /dev/fd symlink");

2829

}

2830

}

2831

2146

TEMP_FAILURE_RETRY(close(pubkey_fd));

2147

}

2148

}

2149

2832

2150

/* Lower privileges */

2833

ret = lower_privileges();

2834

if(ret != 0){

2835

errno = ret;

2151

ret_errno = lower_privileges();

2152

if(ret_errno != 0){

2153

errno = ret_errno;

2836

2154

perror_plus("Failed to lower privileges");

2837

2155

}

2838

2156

}

3008

2326

errno = bring_up_interface(interface, delay);

3009

2327

if(not interface_was_up){

3010

2328

if(errno != 0){

3011

fprintf_plus(stderr, "Failed to bring up interface \"%s\":"

3012

" %s\n", interface, strerror(errno));

2329

perror_plus("Failed to bring up interface");

3013

2330

} else {

3014

2331

errno = argz_add(&interfaces_to_take_down,

3015

2332

&interfaces_to_take_down_size,

3038

2355

goto end;

3039

2356

}

3040

2357

3041

#if GNUTLS_VERSION_NUMBER >= 0x030606

3042

ret = init_gnutls_global(tls_pubkey, tls_privkey, dh_params_file, &mc);

3043

#elif GNUTLS_VERSION_NUMBER < 0x030600

3044

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

3045

#else

3046

#error "Needs GnuTLS 3.6.6 or later, or before 3.6.0"

3047

#endif

2358

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

3048

2359

if(ret == -1){

3049

2360

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

3050

2361

exitcode = EX_UNAVAILABLE;

3172

2483

3173

2484

/* Allocate a new server */

3174

2485

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

3175

&config, NULL, NULL, &ret);

2486

&config, NULL, NULL, &ret_errno);

3176

2487

3177

2488

/* Free the Avahi configuration data */

3178

2489

avahi_server_config_free(&config);

3181

2492

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

3182

2493

if(mc.server == NULL){

3183

2494

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

3184

avahi_strerror(ret));

2495

avahi_strerror(ret_errno));

3185

2496

exitcode = EX_UNAVAILABLE;

3186

2497

goto end;

3187

2498

}

3222

2533

end:

3223

2534

3224

2535

if(debug){

3225

if(signal_received){

3226

fprintf_plus(stderr, "%s exiting due to signal %d: %s\n",

3227

argv[0], signal_received,

3228

strsignal(signal_received));

3229

} else {

3230

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

3231

}

2536

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

3232

2537

}

3233

2538

3234

2539

/* Cleanup things */

3245

2550

3246

2551

if(gnutls_initialized){

3247

2552

gnutls_certificate_free_credentials(mc.cred);

2553

gnutls_global_deinit();

3248

2554

gnutls_dh_params_deinit(mc.dh_params);

3249

2555

}

3250

2556

3273

2579

3274

2580

/* Re-raise privileges */

3275

2581

{

3276

ret = raise_privileges();

3277

if(ret != 0){

3278

errno = ret;

2582

ret_errno = raise_privileges();

2583

if(ret_errno != 0){

2584

errno = ret_errno;

3279

2585

perror_plus("Failed to raise privileges");

3280

2586

} else {

3281

2587

3286

2592

/* Take down the network interfaces which were brought up */

3287

2593

{

3288

2594

char *interface = NULL;

3289

while((interface = argz_next(interfaces_to_take_down,

3290

interfaces_to_take_down_size,

3291

interface))){

3292

ret = take_down_interface(interface);

3293

if(ret != 0){

3294

errno = ret;

2595

while((interface=argz_next(interfaces_to_take_down,

2596

interfaces_to_take_down_size,

2597

interface))){

2598

ret_errno = take_down_interface(interface);

2599

if(ret_errno != 0){

2600

errno = ret_errno;

3295

2601

perror_plus("Failed to take down interface");

3296

2602

}

3297

2603

}

3302

2608

}

3303

2609

}

3304

2610

3305

ret = lower_privileges_permanently();

3306

if(ret != 0){

3307

errno = ret;

2611

ret_errno = lower_privileges_permanently();

2612

if(ret_errno != 0){

2613

errno = ret_errno;

3308

2614

perror_plus("Failed to lower privileges permanently");

3309

2615

}

3310

2616

}

3312

2618

free(interfaces_to_take_down);

3313

2619

free(interfaces_hooks);

3314

2620

3315

void clean_dir_at(int base, const char * const dirname,

3316

uintmax_t level){

3317

struct dirent **direntries = NULL;

3318

int dret;

3319

int dir_fd = (int)TEMP_FAILURE_RETRY(openat(base, dirname,

3320

O_RDONLY

3321

| O_NOFOLLOW

3322

| O_DIRECTORY

3323

| O_PATH));

3324

if(dir_fd == -1){

3325

perror_plus("open");

3326

return;

3327

}

3328

int numentries = scandirat(dir_fd, ".", &direntries,

3329

notdotentries, alphasort);

3330

if(numentries >= 0){

3331

for(int i = 0; i < numentries; i++){

3332

if(debug){

3333

fprintf_plus(stderr, "Unlinking \"%s/%s\"\n",

3334

dirname, direntries[i]->d_name);

3335

}

3336

dret = unlinkat(dir_fd, direntries[i]->d_name, 0);

3337

if(dret == -1){

3338

if(errno == EISDIR){

3339

dret = unlinkat(dir_fd, direntries[i]->d_name,

3340

AT_REMOVEDIR);

3341

}

3342

if((dret == -1) and (errno == ENOTEMPTY)

3343

and (strcmp(direntries[i]->d_name, "private-keys-v1.d")

3344

== 0) and (level == 0)){

3345

/* Recurse only in this special case */

3346

clean_dir_at(dir_fd, direntries[i]->d_name, level+1);

3347

dret = 0;

3348

}

3349

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

3350

fprintf_plus(stderr, "unlink(\"%s/%s\"): %s\n", dirname,

3351

direntries[i]->d_name, strerror(errno));

3352

}

3353

}

3354

free(direntries[i]);

3355

}

3356

3357

/* need to clean even if 0 because man page doesn't specify */

3358

free(direntries);

3359

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3360

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

3361

perror_plus("rmdir");

3362

}

3363

} else {

3364

perror_plus("scandirat");

3365

}

3366

close(dir_fd);

3367

}

3368

3369

2621

/* Removes the GPGME temp directory and all files inside */

3370

2622

if(tempdir != NULL){

3371

clean_dir_at(-1, tempdir, 0);

2623

struct dirent **direntries = NULL;

2624

int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY |

2625

O_NOFOLLOW));

2626

if(tempdir_fd == -1){

2627

perror_plus("open");

2628

} else {

2629

#ifdef __GLIBC__

2630

#if __GLIBC_PREREQ(2, 15)

2631

int numentries = scandirat(tempdir_fd, ".", &direntries,

2632

notdotentries, alphasort);

2633

#else /* not __GLIBC_PREREQ(2, 15) */

2634

int numentries = scandir(tempdir, &direntries, notdotentries,

2635

alphasort);

2636

#endif /* not __GLIBC_PREREQ(2, 15) */

2637

#else /* not __GLIBC__ */

2638

int numentries = scandir(tempdir, &direntries, notdotentries,

2639

alphasort);

2640

#endif /* not __GLIBC__ */

2641

if(numentries >= 0){

2642

for(int i = 0; i < numentries; i++){

2643

ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);

2644

if(ret == -1){

2645

fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"

2646

" \"%s\", 0): %s\n", tempdir,

2647

direntries[i]->d_name, strerror(errno));

2648

}

2649

free(direntries[i]);

2650

}

2651

2652

/* need to clean even if 0 because man page doesn't specify */

2653

free(direntries);

2654

if(numentries == -1){

2655

perror_plus("scandir");

2656

}

2657

ret = rmdir(tempdir);

2658

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

2659

perror_plus("rmdir");

2660

}

2661

}

2662

TEMP_FAILURE_RETRY(close(tempdir_fd));

2663

}

3372

2664

}

3373

2665

3374

2666

if(quit_now){