1 files changed, 156 insertions, 0 deletions
diff --git a/src/lib/entropy/egd/es_egd.cpp b/src/lib/entropy/egd/es_egd.cpp
new file mode 100644
index 000000000..d8dbecd44
--- /dev/null
+++ b/src/lib/entropy/egd/es_egd.cpp
@@ -0,0 +1,156 @@
+/*
+* EGD EntropySource
+* (C) 1999-2009 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/internal/es_egd.h>
+#include <botan/parsing.h>
+#include <botan/exceptn.h>
+#include <cstring>
+#include <stdexcept>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#ifndef PF_LOCAL
+  #define PF_LOCAL PF_UNIX
+#endif
+
+namespace Botan {
+
+EGD_EntropySource::EGD_Socket::EGD_Socket(const std::string& path) :
+   socket_path(path), m_fd(-1)
+   {
+   }
+
+/**
+* Attempt a connection to an EGD/PRNGD socket
+*/
+int EGD_EntropySource::EGD_Socket::open_socket(const std::string& path)
+   {
+   int fd = ::socket(PF_LOCAL, SOCK_STREAM, 0);
+
+   if(fd >= 0)
+      {
+      sockaddr_un addr;
+      std::memset(&addr, 0, sizeof(addr));
+      addr.sun_family = PF_LOCAL;
+
+      if(sizeof(addr.sun_path) < path.length() + 1)
+         throw std::invalid_argument("EGD socket path is too long");
+
+      std::strncpy(addr.sun_path, path.c_str(), sizeof(addr.sun_path));
+
+      int len = sizeof(addr.sun_family) + std::strlen(addr.sun_path) + 1;
+
+      if(::connect(fd, reinterpret_cast<struct ::sockaddr*>(&addr), len) < 0)
+         {
+         ::close(fd);
+         fd = -1;
+         }
+      }
+
+   return fd;
+   }
+
+/**
+* Attempt to read entropy from EGD
+*/
+size_t EGD_EntropySource::EGD_Socket::read(byte outbuf[], size_t length)
+   {
+   if(length == 0)
+      return 0;
+
+   if(m_fd < 0)
+      {
+      m_fd = open_socket(socket_path);
+      if(m_fd < 0)
+         return 0;
+      }
+
+   try
+      {
+      // 1 == EGD command for non-blocking read
+      byte egd_read_command[2] = {
+         1, static_cast<byte>(std::min<size_t>(length, 255)) };
+
+      if(::write(m_fd, egd_read_command, 2) != 2)
+         throw std::runtime_error("Writing entropy read command to EGD failed");
+
+      byte out_len = 0;
+      if(::read(m_fd, &out_len, 1) != 1)
+         throw std::runtime_error("Reading response length from EGD failed");
+
+      if(out_len > egd_read_command[1])
+         throw std::runtime_error("Bogus length field received from EGD");
+
+      ssize_t count = ::read(m_fd, outbuf, out_len);
+
+      if(count != out_len)
+         throw std::runtime_error("Reading entropy result from EGD failed");
+
+      return static_cast<size_t>(count);
+      }
+   catch(std::exception)
+      {
+      this->close();
+      // Will attempt to reopen next poll
+      }
+
+   return 0;
+   }
+
+void EGD_EntropySource::EGD_Socket::close()
+   {
+   if(m_fd > 0)
+      {
+      ::close(m_fd);
+      m_fd = -1;
+      }
+   }
+
+/**
+* EGD_EntropySource constructor
+*/
+EGD_EntropySource::EGD_EntropySource(const std::vector<std::string>& paths)
+   {
+   for(size_t i = 0; i != paths.size(); ++i)
+      sockets.push_back(EGD_Socket(paths[i]));
+   }
+
+EGD_EntropySource::~EGD_EntropySource()
+   {
+   for(size_t i = 0; i != sockets.size(); ++i)
+      sockets[i].close();
+   sockets.clear();
+   }
+
+/**
+* Gather Entropy from EGD
+*/
+void EGD_EntropySource::poll(Entropy_Accumulator& accum)
+   {
+   size_t go_get = std::min<size_t>(accum.desired_remaining_bits() / 8, 32);
+
+   secure_vector<byte>& io_buffer = accum.get_io_buffer(go_get);
+
+   for(size_t i = 0; i != sockets.size(); ++i)
+      {
+      size_t got = sockets[i].read(&io_buffer[0], io_buffer.size());
+
+      if(got)
+         {
+         accum.add(&io_buffer[0], got, 6);
+         break;
+         }
+      }
+   }
+
+}