tools/elftosb/common/Random.cpp

   1 /*
   2  * File:        Random.cpp
   3  *
   4  * Copyright (c) Freescale Semiconductor, Inc. All rights reserved.
   5  * See included license file for license details.
   6  */
   7
   8 #include "Random.h"
   9 #include <stdexcept>
  10
  11 #ifdef WIN32
  12         #ifndef _WIN32_WINNT
  13                 #define _WIN32_WINNT 0x0400
  14         #endif
  15         #include <windows.h>
  16         #include <wincrypt.h>
  17 #else   // WIN32
  18         #include <errno.h>
  19         #include <fcntl.h>
  20         #include <unistd.h>
  21 #endif  // WIN32
  22
  23
  24
  25 #ifdef WIN32
  26
  27 MicrosoftCryptoProvider::MicrosoftCryptoProvider()
  28 {
  29         if(!CryptAcquireContext(&m_hProvider, 0, 0, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
  30         {
  31                 throw std::runtime_error("CryptAcquireContext");
  32         }
  33 }
  34
  35 MicrosoftCryptoProvider::~MicrosoftCryptoProvider()
  36 {
  37         CryptReleaseContext(m_hProvider, 0);
  38 }
  39
  40 #endif  // WIN32
  41
  42 RandomNumberGenerator::RandomNumberGenerator()
  43 {
  44 #ifndef WIN32
  45         m_fd = open("/dev/urandom",O_RDONLY);
  46         if (m_fd == -1)
  47         {
  48                 throw std::runtime_error("open /dev/urandom");
  49         }
  50 #endif  // WIN32
  51 }
  52
  53 RandomNumberGenerator::~RandomNumberGenerator()
  54 {
  55 #ifndef WIN32
  56         close(m_fd);
  57 #endif  // WIN32
  58 }
  59
  60 uint8_t RandomNumberGenerator::generateByte()
  61 {
  62         uint8_t result;
  63         generateBlock(&result, 1);
  64         return result;
  65 }
  66
  67 void RandomNumberGenerator::generateBlock(uint8_t * output, unsigned count)
  68 {
  69 #ifdef WIN32
  70 #       ifdef WORKAROUND_MS_BUG_Q258000
  71                 static MicrosoftCryptoProvider m_provider;
  72 #       endif
  73         if (!CryptGenRandom(m_provider.GetProviderHandle(), count, output))
  74         {
  75                 throw std::runtime_error("CryptGenRandom");
  76         }
  77 #else   // WIN32
  78         if (read(m_fd, output, count) != count)
  79         {
  80                 throw std::runtime_error("read /dev/urandom");
  81         }
  82 #endif  // WIN32
  83 }
  84
  85