pdns/randomhelper.cc

   1 #ifdef HAVE_CONFIG_H
   2 #include "config.h"
   3 #endif
   4 #include "misc.hh"
   5 #include "logger.hh"
   6 #include <sys/types.h>
   7 #include <sys/stat.h>
   8 #include <fcntl.h>
   9 #include <unistd.h>
  10 #include "dns_random.hh"
  11
  12 void seedRandom(const string& source)
  13 {
  14   L<<Logger::Warning<<"Reading random entropy from '"<<source<<"'"<<endl;
  15
  16   int fd=open(source.c_str(), O_RDONLY);
  17   if(fd < 0) {
  18     L<<Logger::Error<<"Unable to open source of random '"<<source<<"': "<<stringerror()<<endl;
  19     exit(EXIT_FAILURE);
  20   }
  21   char seed[16];
  22   int ret;
  23   int pos=0;
  24   while(pos!=sizeof(seed)) {
  25     ret = read(fd, seed+pos, sizeof(seed)-pos);
  26     if(ret < 0) {
  27       L<<Logger::Error<<"Unable to read random seed from "<<source<<": "<<stringerror()<<endl;
  28       close(fd);
  29       exit(EXIT_FAILURE);
  30     }
  31     if(!ret) {
  32       L<<Logger::Error<<"Unable to read random seed from "<<source<<": end of file"<<endl;
  33       close(fd);
  34       exit(EXIT_FAILURE);
  35     }
  36     pos+=ret;
  37   }
  38   close(fd);
  39   dns_random_init(seed);
  40 }