code.delx.au - pulseaudio/blob - src/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
  37 #include "authkey.h"
  38 #include "util.h"
  39
  40 #define RANDOM_DEVICE "/dev/urandom"
  41
  42 static int load(const char *fn, void *data, size_t length) {
  43     int fd = -1, ret = -1;
  44     ssize_t r;
  45
  46     assert(fn && data && length);
  47
  48     if ((fd = open(fn, O_RDONLY)) < 0)
  49         goto finish;
  50
  51     if ((r = pa_loop_read(fd, data, length)) < 0 || (size_t) r != length) {
  52         ret = -2;
  53         goto finish;
  54     }
  55
  56     ret = 0;
  57
  58 finish:
  59     if (fd >= 0)
  60         close(fd);
  61
  62     return ret;
  63 }
  64
  65 static int generate(const char *fn, void *data, size_t length) {
  66     int fd = -1, random_fd = -1, ret = -1;
  67     ssize_t r;
  68     assert(fn && data && length);
  69
  70     if ((fd = open(fn, O_WRONLY|O_EXCL|O_CREAT, S_IRUSR | S_IWUSR)) < 0)
  71         goto finish;
  72
  73     if ((random_fd = open(RANDOM_DEVICE, O_RDONLY)) >= 0) {
  74
  75         if ((r = pa_loop_read(random_fd, data, length)) < 0 || (size_t) r != length) {
  76             ret = -2;
  77             goto finish;
  78         }
  79
  80     } else {
  81         uint8_t *p;
  82         size_t l;
  83         fprintf(stderr, "WARNING: Failed to open entropy device '"RANDOM_DEVICE"': %s, falling back to unsecure pseudo RNG.\n", strerror(errno));
  84
  85         srandom(time(NULL));
  86
  87         for (p = data, l = length; l > 0; p++, l--)
  88             *p = (uint8_t) random();
  89     }
  90
  91     if ((r = pa_loop_write(fd, data, length)) < 0 || (size_t) r != length) {
  92         ret =  -2;
  93         goto finish;
  94     }
  95
  96     ret = 0;
  97
  98 finish:
  99     if (fd >= 0) {
 100         if (ret != 0)
 101             unlink(fn);
 102         close(fd);
 103     }
 104     if (random_fd >= 0)
 105         close(random_fd);
 106
 107     return ret;
 108 }
 109
 110 int pa_authkey_load(const char *path, void *data, size_t length) {
 111     int ret, i;
 112
 113     assert(path && data && length);
 114
 115     for (i = 0; i < 10; i++) {
 116         if ((ret = load(path, data, length)) < 0)
 117             if (ret == -1 && errno == ENOENT)
 118                 if ((ret = generate(path,  data, length)) < 0)
 119                     if (ret == -1 && errno == EEXIST)
 120                         continue;
 121         break;
 122     }
 123
 124     if (ret < 0)
 125         fprintf(stderr, "Failed to load authorization key '%s': %s\n", path, (ret == -1) ? strerror(errno) : "file corrupt");
 126
 127     return ret;
 128 }
 129
 130 int pa_authkey_load_from_home(const char *fn, void *data, size_t length) {
 131     char *home;
 132     char path[PATH_MAX];
 133
 134     assert(fn && data && length);
 135
 136     if (!(home = getenv("HOME")))
 137         return -2;
 138
 139     snprintf(path, sizeof(path), "%s/%s", home, fn);
 140
 141     return pa_authkey_load(path, data, length);
 142 }
 143
 144 int pa_authkey_load_auto(const char *fn, void *data, size_t length) {
 145     assert(fn && data && length);
 146
 147     if (*fn == '/')
 148         return pa_authkey_load(fn, data, length);
 149     else
 150         return pa_authkey_load_from_home(fn, data, length);
 151 }