release/src/router/tinc/src/openssl/crypto.c

   1 /*
   2     crypto.c -- Cryptographic miscellaneous functions and initialisation
   3     Copyright (C) 2007-2014 Guus Sliepen <guus@tinc-vpn.org>
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License along
  16     with this program; if not, write to the Free Software Foundation, Inc.,
  17     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include "../system.h"
  21
  22 #include <openssl/rand.h>
  23 #include <openssl/evp.h>
  24 #include <openssl/engine.h>
  25
  26 #include "../crypto.h"
  27
  28 #ifndef HAVE_MINGW
  29
  30 static int random_fd = -1;
  31
  32 static void random_init(void) {
  33         random_fd = open("/dev/urandom", O_RDONLY);
  34         if(random_fd < 0)
  35                 random_fd = open("/dev/random", O_RDONLY);
  36         if(random_fd < 0) {
  37                 fprintf(stderr, "Could not open source of random numbers: %s\n", strerror(errno));
  38                 abort();
  39         }
  40 }
  41
  42 static void random_exit(void) {
  43         close(random_fd);
  44 }
  45
  46 void randomize(void *out, size_t outlen) {
  47         while(outlen) {
  48                 size_t len = read(random_fd, out, outlen);
  49                 if(len <= 0) {
  50                         if(errno == EAGAIN || errno == EINTR)
  51                                 continue;
  52                         fprintf(stderr, "Could not read random numbers: %s\n", strerror(errno));
  53                         abort();
  54                 }
  55                 out += len;
  56                 outlen -= len;
  57         }
  58 }
  59
  60 #else
  61
  62 #include <wincrypt.h>
  63 HCRYPTPROV prov;
  64
  65 void random_init(void) {
  66         if(!CryptAcquireContext(&prov, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT)) {
  67                 fprintf(stderr, "CryptAcquireContext() failed!\n");
  68                 abort();
  69         }
  70 }
  71
  72 void random_exit(void) {
  73         CryptReleaseContext(prov, 0);
  74 }
  75
  76 void randomize(void *out, size_t outlen) {
  77         if(!CryptGenRandom(prov, outlen, out)) {
  78                 fprintf(stderr, "CryptGenRandom() failed\n");
  79                 abort();
  80         }
  81 }
  82
  83 #endif
  84
  85 void crypto_init(void) {
  86         random_init();
  87
  88         ENGINE_load_builtin_engines();
  89         ENGINE_register_all_complete();
  90
  91         ERR_load_crypto_strings();
  92         OpenSSL_add_all_algorithms();
  93
  94         if(!RAND_status()) {
  95                 fprintf(stderr, "Not enough entropy for the PRNG!\n");
  96                 abort();
  97         }
  98 }
  99
 100 void crypto_exit(void) {
 101         EVP_cleanup();
 102         ERR_free_strings();
 103         ENGINE_cleanup();
 104         random_exit();
 105 }