code.delx.au - pulseaudio/blob - polyp/authkey.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of polypaudio.
   5
   6   polypaudio is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published
   8   by the Free Software Foundation; either version 2 of the License,
   9   or (at your option) any later version.
  10
  11   polypaudio is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with polypaudio; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <assert.h>
  27 #include <unistd.h>
  28 #include <fcntl.h>
  29 #include <string.h>
  30 #include <errno.h>
  31 #include <stdio.h>
  32 #include <inttypes.h>
  33 #include <stdlib.h>
  34 #include <time.h>
  35 #include <limits.h>
  36 #include <sys/stat.h>
  37
  38 #include "authkey.h"
  39 #include "util.h"
  40 #include "log.h"
  41
  42 #define RANDOM_DEVICE "/dev/urandom"
  43
  44 static int generate(int fd, void *data, size_t length) {
  45     int random_fd, ret = -1;
  46     ssize_t r;
  47     assert(fd >= 0 && data && length);
  48
  49     if ((random_fd = open(RANDOM_DEVICE, O_RDONLY)) >= 0) {
  50
  51         if ((r = pa_loop_read(random_fd, data, length)) < 0 || (size_t) r != length) {
  52             pa_log(__FILE__": failed to read entropy from '%s'\n", RANDOM_DEVICE);
  53             goto finish;
  54         }
  55
  56     } else {
  57         uint8_t *p;
  58         size_t l;
  59         pa_log(__FILE__": WARNING: Failed to open entropy device '"RANDOM_DEVICE"': %s"
  60                ", falling back to unsecure pseudo RNG.\n", strerror(errno));
  61
  62         srandom(time(NULL));
  63
  64         for (p = data, l = length; l > 0; p++, l--)
  65             *p = (uint8_t) random();
  66     }
  67
  68     lseek(fd, 0, SEEK_SET);
  69
  70     if ((r = pa_loop_write(fd, data, length)) < 0 || (size_t) r != length) {
  71         pa_log(__FILE__": failed to write cookie file: %s\n", strerror(errno));
  72         goto finish;
  73     }
  74
  75     ret = 0;
  76
  77 finish:
  78
  79     if (random_fd >= 0)
  80         close(random_fd);
  81
  82     return ret;
  83 }
  84
  85 static int load(const char *fn, void *data, size_t length) {
  86     int fd = -1;
  87     int writable = 1;
  88     int unlock = 0, ret;
  89     ssize_t r;
  90     assert(fn && data && length);
  91
  92     if ((fd = open(fn, O_RDWR|O_CREAT, S_IRUSR|S_IWUSR)) < 0) {
  93         if (errno != EACCES || (fd = open(fn, O_RDONLY)) < 0) {
  94             pa_log(__FILE__": failed to open cookie file '%s': %s\n", fn, strerror(errno));
  95             goto finish;
  96         } else
  97             writable = 0;
  98     }
  99
 100     unlock = pa_lock_fd(fd, 1) >= 0;
 101
 102     if ((r = pa_loop_read(fd, data, length)) < 0) {
 103         pa_log(__FILE__": failed to read cookie file '%s': %s\n", fn, strerror(errno));
 104         goto finish;
 105     }
 106
 107     if ((size_t) r != length) {
 108
 109         if (!writable) {
 110             pa_log(__FILE__": unable to write cookie to read only file\n");
 111             goto finish;
 112         }
 113
 114         if (generate(fd, data, length) < 0)
 115             goto finish;
 116     }
 117
 118     ret = 0;
 119
 120 finish:
 121
 122     if (fd >= 0) {
 123
 124         if (unlock)
 125             pa_lock_fd(fd, 0);
 126
 127         close(fd);
 128     }
 129
 130     return ret;
 131 }
 132
 133 int pa_authkey_load(const char *path, void *data, size_t length) {
 134     int ret;
 135
 136     assert(path && data && length);
 137
 138     ret = load(path, data, length);
 139
 140     if (ret < 0)
 141         pa_log(__FILE__": Failed to load authorization key '%s': %s\n", path,
 142                (ret == -1) ? strerror(errno) : "file corrupt");
 143
 144     return ret;
 145 }
 146
 147 static const char *normalize_path(const char *fn, char *s, size_t l) {
 148     assert(fn && s && l > 0);
 149
 150     if (fn[0] != '/') {
 151         char homedir[PATH_MAX];
 152         if (!pa_get_home_dir(homedir, sizeof(homedir)))
 153             return NULL;
 154
 155         snprintf(s, l, "%s/%s", homedir, fn);
 156         return s;
 157     }
 158
 159     return fn;
 160 }
 161
 162 int pa_authkey_load_from_home(const char *fn, void *data, size_t length) {
 163     char path[PATH_MAX];
 164     const char *p;
 165     assert(fn && data && length);
 166
 167     if (!(p = normalize_path(fn, path, sizeof(path))))
 168         return -2;
 169
 170     return pa_authkey_load(p, data, length);
 171 }
 172
 173 int pa_authkey_load_auto(const char *fn, void *data, size_t length) {
 174     assert(fn && data && length);
 175
 176     if (*fn == '/')
 177         return pa_authkey_load(fn, data, length);
 178     else
 179         return pa_authkey_load_from_home(fn, data, length);
 180 }
 181
 182 int pa_authkey_save(const char *fn, const void *data, size_t length) {
 183     int fd = -1;
 184     int unlock = 0, ret = -1;
 185     ssize_t r;
 186     char path[PATH_MAX];
 187     const char *p;
 188     assert(fn && data && length);
 189
 190     if (!(p = normalize_path(fn, path, sizeof(path))))
 191         return -2;
 192
 193     if ((fd = open(p, O_RDWR|O_CREAT, S_IRUSR|S_IWUSR)) < 0) {
 194         pa_log(__FILE__": failed to open cookie file '%s': %s\n", fn, strerror(errno));
 195         goto finish;
 196     }
 197
 198     unlock = pa_lock_fd(fd, 1) >= 0;
 199
 200     if ((r = pa_loop_write(fd, data, length)) < 0 || (size_t) r != length) {
 201         pa_log(__FILE__": failed to read cookie file '%s': %s\n", fn, strerror(errno));
 202         goto finish;
 203     }
 204
 205     ret = 0;
 206
 207 finish:
 208
 209     if (fd >= 0) {
 210
 211         if (unlock)
 212             pa_lock_fd(fd, 0);
 213
 214         close(fd);
 215     }
 216
 217     return ret;
 218 }