1 files changed, 112 insertions, 0 deletions
diff --git a/modules/entropy/dev_random/es_dev.cpp b/modules/entropy/dev_random/es_dev.cpp
new file mode 100644
index 000000000..310620716
--- /dev/null
+++ b/modules/entropy/dev_random/es_dev.cpp
@@ -0,0 +1,112 @@
+/*************************************************
+* Device EntropySource Source File               *
+* (C) 1999-2008 Jack Lloyd                       *
+*************************************************/
+
+#include <botan/es_dev.h>
+#include <sys/select.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/fcntl.h>
+#include <unistd.h>
+
+namespace Botan {
+
+namespace {
+
+/*************************************************
+* A class handling reading from a device         *
+*************************************************/
+class Device_Reader
+   {
+   public:
+      typedef int fd_type;
+
+      Device_Reader(fd_type device_fd) : fd(device_fd) {}
+      ~Device_Reader() { if(fd > 0) { ::close(fd); } }
+      u32bit get(byte out[], u32bit length);
+
+      static fd_type open(const std::string& pathname);
+   private:
+      fd_type fd;
+   };
+
+/*************************************************
+* Read from a device file                        *
+*************************************************/
+u32bit Device_Reader::get(byte out[], u32bit length)
+   {
+   if(fd < 0)
+      return 0;
+
+   if(fd >= FD_SETSIZE)
+      return 0;
+
+   const u32bit READ_WAIT_MS = 10;
+
+   fd_set read_set;
+   FD_ZERO(&read_set);
+   FD_SET(fd, &read_set);
+
+   struct ::timeval timeout;
+   timeout.tv_sec = 0;
+   timeout.tv_usec = READ_WAIT_MS * 1000;
+
+   if(::select(fd + 1, &read_set, 0, 0, &timeout) < 0)
+      return 0;
+
+   if(!(FD_ISSET(fd, &read_set)))
+      return 0;
+
+   const ssize_t got = ::read(fd, out, length);
+   if(got <= 0)
+      return 0;
+
+   const u32bit ret = static_cast<u32bit>(got);
+
+   if(ret > length)
+      return 0;
+
+   return ret;
+   }
+
+/*************************************************
+* Attempt to open a device                       *
+*************************************************/
+int Device_Reader::open(const std::string& pathname)
+   {
+#ifndef O_NONBLOCK
+  #define O_NONBLOCK 0
+#endif
+
+#ifndef O_NOCTTY
+  #define O_NOCTTY 0
+#endif
+
+   const int flags = O_RDONLY | O_NONBLOCK | O_NOCTTY;
+   return ::open(pathname.c_str(), flags);
+   }
+
+}
+
+/*************************************************
+* Gather entropy from a RNG device               *
+*************************************************/
+u32bit Device_EntropySource::slow_poll(byte output[], u32bit length)
+   {
+   u32bit read = 0;
+
+   for(size_t j = 0; j != fsnames.size(); ++j)
+      {
+      Device_Reader reader(Device_Reader::open(fsnames[j]));
+
+      read += reader.get(output + read, length - read);
+
+      if(read == length)
+         break;
+      }
+
+   return read;
+   }
+
+}