1 files changed, 110 insertions, 0 deletions
diff --git a/modules/es_ftw/es_ftw.cpp b/modules/es_ftw/es_ftw.cpp
new file mode 100644
index 000000000..08a03c0e4
--- /dev/null
+++ b/modules/es_ftw/es_ftw.cpp
@@ -0,0 +1,110 @@
+/*************************************************
+* FTW EntropySource Source File                  *
+* (C) 1999-2006 The Botan Project                *
+*************************************************/
+
+#include <botan/es_ftw.h>
+#include <botan/util.h>
+#include <fstream>
+#include <cstring>
+#include <vector>
+
+#ifndef _POSIX_C_SOURCE
+  #define _POSIX_C_SOURCE 199309
+#endif
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <fcntl.h>
+
+namespace Botan {
+
+/*************************************************
+* FTW_EntropySource Constructor                  *
+*************************************************/
+FTW_EntropySource::FTW_EntropySource(const std::string& p) : path(p)
+   {
+   }
+
+/*************************************************
+* FTW Fast Poll                                  *
+*************************************************/
+void FTW_EntropySource::do_fast_poll()
+   {
+   files_read = 0;
+   max_read = 32;
+   gather_from_dir(path);
+   }
+
+/*************************************************
+* FTW Slow Poll                                  *
+*************************************************/
+void FTW_EntropySource::do_slow_poll()
+   {
+   files_read = 0;
+   max_read = 256;
+   gather_from_dir(path);
+   }
+
+/*************************************************
+* Gather Entropy From Directory Tree             *
+*************************************************/
+void FTW_EntropySource::gather_from_dir(const std::string& dirname)
+   {
+   if(dirname == "" || files_read >= max_read)
+      return;
+
+   DIR* dir = opendir(dirname.c_str());
+   if(dir == 0)
+      return;
+
+   std::vector<std::string> subdirs;
+
+   dirent* entry = readdir(dir);
+   while(entry && (files_read < max_read))
+      {
+      if((std::strcmp(entry->d_name, ".") == 0) ||
+         (std::strcmp(entry->d_name, "..") == 0))
+         { entry = readdir(dir); continue; }
+
+      const std::string filename = dirname + '/' + entry->d_name;
+
+      struct stat stat_buf;
+      if(lstat(filename.c_str(), &stat_buf) == -1)
+         { entry = readdir(dir); continue; }
+
+      if(S_ISREG(stat_buf.st_mode))
+         gather_from_file(filename);
+      else if(S_ISDIR(stat_buf.st_mode))
+         subdirs.push_back(filename);
+      entry = readdir(dir);
+      }
+   closedir(dir);
+
+   for(u32bit j = 0; j != subdirs.size(); j++)
+      gather_from_dir(subdirs[j]);
+   }
+
+/*************************************************
+* Gather Entropy From A File                     *
+*************************************************/
+void FTW_EntropySource::gather_from_file(const std::string& filename)
+   {
+   int fd = ::open(filename.c_str(), O_RDONLY | O_NOCTTY);
+   if(fd == -1)
+      return;
+
+   SecureVector<byte> read_buf(1024);
+   ssize_t got = ::read(fd, (byte*)read_buf.begin(), read_buf.size());
+   close(fd);
+
+   if(got > 0)
+      {
+      add_bytes(read_buf, got);
+      files_read++;
+      }
+   }
+
+}