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 Lesser General Public License as
   8   published by the Free Software Foundation; either version 2.1 of the
   9   License, 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   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public
  17   License 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 #include "random.h"
  42
  43 /* Generate a new authorization key, store it in file fd and return it in *data  */
  44 static int generate(int fd, void *ret_data, size_t length) {
  45     ssize_t r;
  46     assert(fd >= 0 && ret_data && length);
  47
  48     pa_random(ret_data, length);
  49
  50     lseek(fd, 0, SEEK_SET);
  51     ftruncate(fd, 0);
  52
  53     if ((r = pa_loop_write(fd, ret_data, length)) < 0 || (size_t) r != length) {
  54         pa_log(__FILE__": failed to write cookie file: %s\n", strerror(errno));
  55         return -1;
  56     }
  57
  58     return 0;
  59 }
  60
  61 /* Load an euthorization cookie from file fn and store it in data. If
  62  * the cookie file doesn't exist, create it */
  63 static int load(const char *fn, void *data, size_t length) {
  64     int fd = -1;
  65     int writable = 1;
  66     int unlock = 0, ret;
  67     ssize_t r;
  68     assert(fn && data && length);
  69
  70     if ((fd = open(fn, O_RDWR|O_CREAT, S_IRUSR|S_IWUSR)) < 0) {
  71         if (errno != EACCES || (fd = open(fn, O_RDONLY)) < 0) {
  72             pa_log(__FILE__": failed to open cookie file '%s': %s\n", fn, strerror(errno));
  73             goto finish;
  74         } else
  75             writable = 0;
  76     }
  77
  78     unlock = pa_lock_fd(fd, 1) >= 0;
  79
  80     if ((r = pa_loop_read(fd, data, length)) < 0) {
  81         pa_log(__FILE__": failed to read cookie file '%s': %s\n", fn, strerror(errno));
  82         goto finish;
  83     }
  84
  85     if ((size_t) r != length) {
  86
  87         if (!writable) {
  88             pa_log(__FILE__": unable to write cookie to read only file\n");
  89             goto finish;
  90         }
  91
  92         if (generate(fd, data, length) < 0)
  93             goto finish;
  94     }
  95
  96     ret = 0;
  97
  98 finish:
  99
 100     if (fd >= 0) {
 101
 102         if (unlock)
 103             pa_lock_fd(fd, 0);
 104
 105         close(fd);
 106     }
 107
 108     return ret;
 109 }
 110
 111 /* Load a cookie from a cookie file. If the file doesn't exist, create it. */
 112 int pa_authkey_load(const char *path, void *data, size_t length) {
 113     int ret;
 114
 115     assert(path && data && length);
 116
 117     ret = load(path, data, length);
 118
 119     if (ret < 0)
 120         pa_log(__FILE__": Failed to load authorization key '%s': %s\n", path,
 121                (ret == -1) ? strerror(errno) : "file corrupt");
 122
 123     return ret;
 124 }
 125
 126 /* If the specified file path starts with / return it, otherwise
 127  * return path prepended with home directory */
 128 static const char *normalize_path(const char *fn, char *s, size_t l) {
 129     assert(fn && s && l > 0);
 130
 131     if (fn[0] != '/') {
 132         char homedir[PATH_MAX];
 133         if (!pa_get_home_dir(homedir, sizeof(homedir)))
 134             return NULL;
 135
 136         snprintf(s, l, "%s/%s", homedir, fn);
 137         return s;
 138     }
 139
 140     return fn;
 141 }
 142
 143 /* Load a cookie from a file in the home directory. If the specified
 144  * path starts with /, use it as absolute path instead. */
 145 int pa_authkey_load_auto(const char *fn, void *data, size_t length) {
 146     char path[PATH_MAX];
 147     const char *p;
 148     assert(fn && data && length);
 149
 150     if (!(p = normalize_path(fn, path, sizeof(path))))
 151         return -2;
 152
 153     return pa_authkey_load(p, data, length);
 154 }
 155
 156 /* Store the specified cookie in the speicified cookie file */
 157 int pa_authkey_save(const char *fn, const void *data, size_t length) {
 158     int fd = -1;
 159     int unlock = 0, ret = -1;
 160     ssize_t r;
 161     char path[PATH_MAX];
 162     const char *p;
 163     assert(fn && data && length);
 164
 165     if (!(p = normalize_path(fn, path, sizeof(path))))
 166         return -2;
 167
 168     if ((fd = open(p, O_RDWR|O_CREAT, S_IRUSR|S_IWUSR)) < 0) {
 169         pa_log(__FILE__": failed to open cookie file '%s': %s\n", fn, strerror(errno));
 170         goto finish;
 171     }
 172
 173     unlock = pa_lock_fd(fd, 1) >= 0;
 174
 175     if ((r = pa_loop_write(fd, data, length)) < 0 || (size_t) r != length) {
 176         pa_log(__FILE__": failed to read cookie file '%s': %s\n", fn, strerror(errno));
 177         goto finish;
 178     }
 179
 180     ret = 0;
 181
 182 finish:
 183
 184     if (fd >= 0) {
 185
 186         if (unlock)
 187             pa_lock_fd(fd, 0);
 188
 189         close(fd);
 190     }
 191
 192     return ret;
 193 }