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
  37 #include "authkey.h"
  38 #include "util.h"
  39 #include "log.h"
  40
  41 #define RANDOM_DEVICE "/dev/urandom"
  42
  43 static int load(const char *fn, void *data, size_t length) {
  44     int fd = -1, ret = -1;
  45     ssize_t r;
  46
  47     assert(fn && data && length);
  48
  49     if ((fd = open(fn, O_RDONLY)) < 0)
  50         goto finish;
  51
  52     if ((r = pa_loop_read(fd, data, length)) < 0 || (size_t) r != length) {
  53         ret = -2;
  54         goto finish;
  55     }
  56
  57     ret = 0;
  58
  59 finish:
  60     if (fd >= 0)
  61         close(fd);
  62
  63     return ret;
  64 }
  65
  66 static int generate(const char *fn, void *data, size_t length) {
  67     int fd = -1, random_fd = -1, ret = -1;
  68     ssize_t r;
  69     assert(fn && data && length);
  70
  71     if ((fd = open(fn, O_WRONLY|O_EXCL|O_CREAT, S_IRUSR | S_IWUSR)) < 0)
  72         goto finish;
  73
  74     if ((random_fd = open(RANDOM_DEVICE, O_RDONLY)) >= 0) {
  75
  76         if ((r = pa_loop_read(random_fd, data, length)) < 0 || (size_t) r != length) {
  77             ret = -2;
  78             goto finish;
  79         }
  80
  81     } else {
  82         uint8_t *p;
  83         size_t l;
  84         pa_log(__FILE__": WARNING: Failed to open entropy device '"RANDOM_DEVICE"': %s, falling back to unsecure pseudo RNG.\n", strerror(errno));
  85
  86         srandom(time(NULL));
  87
  88         for (p = data, l = length; l > 0; p++, l--)
  89             *p = (uint8_t) random();
  90     }
  91
  92     if ((r = pa_loop_write(fd, data, length)) < 0 || (size_t) r != length) {
  93         ret =  -2;
  94         goto finish;
  95     }
  96
  97     ret = 0;
  98
  99 finish:
 100     if (fd >= 0) {
 101         if (ret != 0)
 102             unlink(fn);
 103         close(fd);
 104     }
 105     if (random_fd >= 0)
 106         close(random_fd);
 107
 108     return ret;
 109 }
 110
 111 int pa_authkey_load(const char *path, void *data, size_t length) {
 112     int ret, i;
 113
 114     assert(path && data && length);
 115
 116     for (i = 0; i < 10; i++) {
 117         if ((ret = load(path, data, length)) < 0)
 118             if (ret == -1 && errno == ENOENT)
 119                 if ((ret = generate(path,  data, length)) < 0)
 120                     if (ret == -1 && errno == EEXIST)
 121                         continue;
 122         break;
 123     }
 124
 125     if (ret < 0)
 126         pa_log(__FILE__": Failed to load authorization key '%s': %s\n", path, (ret == -1) ? strerror(errno) : "file corrupt");
 127
 128     return ret;
 129 }
 130
 131 int pa_authkey_load_from_home(const char *fn, void *data, size_t length) {
 132     char *home;
 133     char path[PATH_MAX];
 134
 135     assert(fn && data && length);
 136
 137     if (!(home = getenv("HOME")))
 138         return -2;
 139
 140     snprintf(path, sizeof(path), "%s/%s", home, fn);
 141
 142     return pa_authkey_load(path, data, length);
 143 }
 144
 145 int pa_authkey_load_auto(const char *fn, void *data, size_t length) {
 146     assert(fn && data && length);
 147
 148     if (*fn == '/')
 149         return pa_authkey_load(fn, data, length);
 150     else
 151         return pa_authkey_load_from_home(fn, data, length);
 152 }