propagate from branch 'net.randombit.botan' (head 4518ef63a5e28e22a61d21a6066d0d4a5cf0616e)

            to branch 'net.randombit.botan.entropy-poll-redesign' (head c8e07f10a193b25bab726af99ea2ea77a0f30eaf)

35 files changed, 704 insertions, 863 deletions

diff --git a/checks/common.h b/checks/common.h
index ac3daaf76..fa41882ee 100644
--- a/checks/common.h
+++ b/checks/common.h
@@ -67,6 +67,8 @@ class Fixed_Output_RNG : public Botan::RandomNumberGenerator
          return out;
          }
 
+      void reseed(u32bit) {}
+
       void randomize(byte out[], u32bit len)
          {
          for(u32bit j = 0; j != len; j++)
diff --git a/doc/examples/test_es.cpp b/doc/examples/test_es.cpp
index 18531b326..b7b2e9162 100644
--- a/doc/examples/test_es.cpp
+++ b/doc/examples/test_es.cpp
@@ -32,27 +32,40 @@
 
 using namespace Botan;
 
+class Saver_Of_Bytes : public BufferedComputation
+   {
+   public:
+      Saver_Of_Bytes() : BufferedComputation(0), outbuf(64), written(0) {}
+      void add_data(const byte in[], u32bit length)
+         {
+         for(size_t i = 0; i != length; ++i)
+            outbuf[i % outbuf.size()] ^= in[i];
+
+         written += length;
+         //outbuf.insert(outbuf.end(), in, in+length);
+         }
+      void final_result(byte[]) { if(written < 64) outbuf.resize(written); }
+
+      std::vector<byte> outbuf;
+      u32bit written;
+   };
+
 void test_entropy_source(EntropySource* es)
    {
    // sometimes iostreams really is just a pain
 
-   // upper buffer size of 96 to match HMAC_RNG's
-   byte buf[96] = { 0 };
-
    printf("Polling '%s':\n", es->name().c_str());
 
-   printf("  Fast poll... ");
-   u32bit fast_poll_got = es->fast_poll(buf, sizeof(buf));
-   printf("got %d bytes: ", fast_poll_got);
-   for(u32bit i = 0; i != fast_poll_got; ++i)
-      printf("%02X", buf[i]);
-   printf("\n");
+   Saver_Of_Bytes save;
+
+   Entropy_Accumulator accum(save, 128);
+   es->poll(accum);
+
+   save.final_result(0);
 
-   printf("  Slow poll... ");
-   u32bit slow_poll_got = es->slow_poll(buf, sizeof(buf));
-   printf("got %d bytes: ", slow_poll_got);
-   for(u32bit i = 0; i != slow_poll_got; ++i)
-      printf("%02X", buf[i]);
+   printf("Got %d bytes\n", save.written);
+   for(size_t i = 0; i != save.outbuf.size(); ++i)
+      printf("%02X", save.outbuf[i]);
    printf("\n");
 
    delete es;
diff --git a/doc/license.txt b/doc/license.txt
index 0f281171c..4c3fc1999 100644
--- a/doc/license.txt
+++ b/doc/license.txt
@@ -1,4 +1,4 @@
-Copyright (C) 1999-2008 Jack Lloyd
+Copyright (C) 1999-2009 Jack Lloyd
               2001 Peter J Jones
               2004-2007 Justin Karneges
               2005 Matthew Gregan
diff --git a/src/entropy/beos_stats/es_beos.cpp b/src/entropy/beos_stats/es_beos.cpp
index b5a5e7fee..02a751e6a 100644
--- a/src/entropy/beos_stats/es_beos.cpp
+++ b/src/entropy/beos_stats/es_beos.cpp
@@ -4,7 +4,6 @@
 */
 
 #include <botan/es_beos.h>
-#include <botan/xor_buf.h>
 
 #include <kernel/OS.h>
 #include <kernel/image.h>
@@ -13,69 +12,52 @@
 namespace Botan {
 
 /**
-* BeOS Fast Poll
+* BeOS entropy poll
 */
-u32bit BeOS_EntropySource::fast_poll(byte buf[], u32bit length)
+void BeOS_EntropySource::poll(Entropy_Accumulator& accum)
    {
-   if(length == 0)
-      return 0;
-   length = std::min<u32bit>(length, 32);
-
-   u32bit buf_i = 0;
-
    system_info info_sys;
    get_system_info(&info_sys);
-   buf_i = xor_into_buf(buf, buf_i, length, info_sys);
+   accum.add(info_sys, 2);
 
-   key_info info_key;
+   key_info info_key; // current state of the keyboard
    get_key_info(&info_key);
-   buf_i = xor_into_buf(buf, buf_i, length, key_info);
-
-   buf_i = xor_into_buf(buf, buf_i, length, idle_time());
-
-   return length;
-   }
+   accum.add(info_key, 0);
 
-/**
-* BeOS slow poll
-*/
-u32bit BeOS_EntropySource::slow_poll(byte buf[], u32bit length)
-   {
-   if(length == 0)
-      return 0;
+   accum.add(idle_time(), 0);
 
-   u32bit buf_i = 0;
    team_info info_team;
    int32 cookie_team = 0;
 
    while(get_next_team_info(&cookie_team, &info_team) == B_OK)
       {
-      buf_i = xor_into_buf(buf, buf_i, length, info_team);
+      accum.add(info_team, 2);
 
       team_id id = info_team.team;
       int32 cookie = 0;
 
       thread_info info_thr;
       while(get_next_thread_info(id, &cookie, &info_thr) == B_OK)
-         buf_i = xor_into_buf(buf, buf_i, length, info_thr);
+         accum.add(info_thr, 1);
 
       cookie = 0;
       image_info info_img;
       while(get_next_image_info(id, &cookie, &info_img) == B_OK)
-         buf_i = xor_into_buf(buf, buf_i, length, info_img);
+         accum.add(info_img, 1);
 
       cookie = 0;
       sem_info info_sem;
       while(get_next_sem_info(id, &cookie, &info_sem) == B_OK)
-         buf_i = xor_into_buf(buf, buf_i, length, info_sem);
+         accum.add(info_sem, 1);
 
       cookie = 0;
       area_info info_area;
       while(get_next_area_info(id, &cookie, &info_area) == B_OK)
-         buf_i = xor_into_buf(buf, buf_i, length, info_area);
-      }
+         accum.add(info_area, 2);
 
-   return length;
+      if(accum.polling_goal_achieved())
+         break;
+      }
    }
 
 }
diff --git a/src/entropy/beos_stats/es_beos.h b/src/entropy/beos_stats/es_beos.h
index 686ac5c38..0ae670e94 100644
--- a/src/entropy/beos_stats/es_beos.h
+++ b/src/entropy/beos_stats/es_beos.h
@@ -18,8 +18,7 @@ class BOTAN_DLL BeOS_EntropySource : public EntropySource
    private:
       std::string name() const { return "BeOS Statistics"; }
 
-      u32bit fast_poll(byte buf[], u32bit length);
-      u32bit slow_poll(byte buf[], u32bit length);
+      void poll(Entropy_Accumulator& accum);
    };
 
 }
diff --git a/src/entropy/cryptoapi_rng/es_capi.cpp b/src/entropy/cryptoapi_rng/es_capi.cpp
index ca0e1b95e..7cc4d015b 100644
--- a/src/entropy/cryptoapi_rng/es_capi.cpp
+++ b/src/entropy/cryptoapi_rng/es_capi.cpp
@@ -1,7 +1,7 @@
-/*************************************************
-* Win32 CryptoAPI EntropySource Source File      *
-* (C) 1999-2007 Jack Lloyd                       *
-*************************************************/
+/*
+* Win32 CryptoAPI EntropySource
+* (C) 1999-2009 Jack Lloyd
+*/
 
 #include <botan/es_capi.h>
 #include <botan/parsing.h>
@@ -10,71 +10,68 @@
 
 namespace Botan {
 
-/**
-* Gather Entropy from Win32 CAPI
-*/
-u32bit Win32_CAPI_EntropySource::slow_poll(byte output[], u32bit length)
+namespace {
+
+class CSP_Handle
    {
-   return fast_poll(output, length);
-   }
+   public:
+      CSP_Handle(u64bit capi_provider)
+         {
+         valid = false;
+         DWORD prov_type = (DWORD)capi_provider;
+
+         if(CryptAcquireContext(&handle, 0, 0,
+                                prov_type, CRYPT_VERIFYCONTEXT))
+            valid = true;
+         }
+
+      ~CSP_Handle()
+         {
+         if(is_valid())
+            CryptReleaseContext(handle, 0);
+         }
+
+      u32bit gen_random(byte out[], u32bit n) const
+         {
+         if(is_valid() && CryptGenRandom(handle, n, out))
+            return n;
+         return 0;
+         }
+
+      bool is_valid() const { return valid; }
+
+      HCRYPTPROV get_handle() const { return handle; }
+   private:
+      HCRYPTPROV handle;
+      bool valid;
+   };
+
+}
 
 /**
 * Gather Entropy from Win32 CAPI
 */
-u32bit Win32_CAPI_EntropySource::fast_poll(byte output[], u32bit length)
+void Win32_CAPI_EntropySource::poll(Entropy_Accumulator& accum)
    {
-   class CSP_Handle
-      {
-      public:
-         CSP_Handle(u64bit capi_provider)
-            {
-            valid = false;
-            DWORD prov_type = (DWORD)capi_provider;
-
-            if(CryptAcquireContext(&handle, 0, 0,
-                                   prov_type, CRYPT_VERIFYCONTEXT))
-               valid = true;
-            }
-
-         ~CSP_Handle()
-            {
-            if(is_valid())
-               CryptReleaseContext(handle, 0);
-            }
-
-         void gen_random(byte out[], u32bit n) const
-            {
-            if(is_valid())
-               CryptGenRandom(handle, n, out);
-            }
-
-         bool is_valid() const { return valid; }
-
-         HCRYPTPROV get_handle() const { return handle; }
-      private:
-         HCRYPTPROV handle;
-         bool valid;
-      };
-
-
-   if(length > 64)
-      length = 64;
+   MemoryRegion<byte>& io_buffer = accum.get_io_buffer(32);
 
    for(u32bit j = 0; j != prov_types.size(); ++j)
       {
       CSP_Handle csp(prov_types[j]);
-      if(!csp.is_valid())
-         continue;
 
-      csp.gen_random(output, length);
-      break;
+      u32bit got = csp.gen_random(io_buffer.begin(), io_buffer.length());
+
+      if(got)
+         {
+         accum.add(io_buffer.begin(), io_buffer.length(), 8);
+         break;
+         }
       }
-   return length;
    }
 
-/*************************************************
-* Gather Entropy from Win32 CAPI                 *
-*************************************************/
+/**
+* Win32_Capi_Entropysource Constructor
+*/
 Win32_CAPI_EntropySource::Win32_CAPI_EntropySource(const std::string& provs)
    {
    std::vector<std::string> capi_provs = split_on(provs, ':');
diff --git a/src/entropy/cryptoapi_rng/es_capi.h b/src/entropy/cryptoapi_rng/es_capi.h
index b8bbb7507..d727de5dd 100644
--- a/src/entropy/cryptoapi_rng/es_capi.h
+++ b/src/entropy/cryptoapi_rng/es_capi.h
@@ -11,16 +11,15 @@
 
 namespace Botan {
 
-/*************************************************
-* Win32 CAPI Entropy Source                      *
-*************************************************/
+/**
+* Win32 CAPI Entropy Source
+*/
 class BOTAN_DLL Win32_CAPI_EntropySource : public EntropySource
    {
    public:
       std::string name() const { return "Win32 CryptoGenRandom"; }
 
-      u32bit fast_poll(byte[], u32bit);
-      u32bit slow_poll(byte[], u32bit);
+      void poll(Entropy_Accumulator& accum);
 
       Win32_CAPI_EntropySource(const std::string& = "");
    private:
diff --git a/src/entropy/dev_random/es_dev.cpp b/src/entropy/dev_random/es_dev.cpp
index 7b936dbaa..89f981373 100644
--- a/src/entropy/dev_random/es_dev.cpp
+++ b/src/entropy/dev_random/es_dev.cpp
@@ -1,7 +1,7 @@
-/*************************************************
-* Device EntropySource Source File               *
-* (C) 1999-2008 Jack Lloyd                       *
-*************************************************/
+/*
+* /dev/random EntropySource
+* (C) 1999-2009 Jack Lloyd
+*/
 
 #include <botan/es_dev.h>
 
@@ -51,12 +51,7 @@ u32bit Device_EntropySource::Device_Reader::get(byte out[], u32bit length,
    if(got <= 0)
       return 0;
 
-   const u32bit ret = static_cast<u32bit>(got);
-
-   if(ret > length)
-      return 0;
-
-   return ret;
+   return static_cast<u32bit>(got);
    }
 
 /**
@@ -79,6 +74,7 @@ Device_EntropySource::Device_Reader::open(const std::string& pathname)
 
 /**
 Device_EntropySource constructor
+Open a file descriptor to each (available) device in fsnames
 */
 Device_EntropySource::Device_EntropySource(
    const std::vector<std::string>& fsnames)
@@ -92,41 +88,36 @@ Device_EntropySource::Device_EntropySource(
    }
 
 /**
-* Gather entropy from a RNG device
+Device_EntropySource destructor: close all open devices
 */
-u32bit Device_EntropySource::slow_poll(byte output[], u32bit length)
+Device_EntropySource::~Device_EntropySource()
    {
    for(size_t i = 0; i != devices.size(); ++i)
-      {
-      const u32bit got = devices[i].get(output, length, 20);
-
-      if(got)
-         return got;
-      }
-
-   return 0;
+      devices[i].close();
    }
 
 /**
-* Fast poll: try limit to 10 ms wait
+* Gather entropy from a RNG device
 */
-u32bit Device_EntropySource::fast_poll(byte output[], u32bit length)
+void Device_EntropySource::poll(Entropy_Accumulator& accum)
    {
+   u32bit go_get = std::min<u32bit>(accum.desired_remaining_bits() / 8, 16);
+
+   u32bit read_wait_ms = go_get / 16;
+
+   MemoryRegion<byte>& io_buffer = accum.get_io_buffer(go_get);
+
    for(size_t i = 0; i != devices.size(); ++i)
       {
-      const u32bit got = devices[i].get(output, length, 5);
+      u32bit got = devices[i].get(io_buffer.begin(), io_buffer.size(),
+                                  read_wait_ms);
 
       if(got)
-         return got;
+         {
+         accum.add(io_buffer.begin(), got, 8);
+         break;
+         }
       }
-
-   return 0;
-   }
-
-Device_EntropySource::~Device_EntropySource()
-   {
-   for(size_t i = 0; i != devices.size(); ++i)
-      devices[i].close();
    }
 
 }
diff --git a/src/entropy/dev_random/es_dev.h b/src/entropy/dev_random/es_dev.h
index db64b75fa..139f8ec52 100644
--- a/src/entropy/dev_random/es_dev.h
+++ b/src/entropy/dev_random/es_dev.h
@@ -1,7 +1,7 @@
-/*************************************************
-* Device EntropySource Header File               *
-* (C) 1999-2007 Jack Lloyd                       *
-*************************************************/
+/*
+* /dev/random EntropySource
+* (C) 1999-2009 Jack Lloyd
+*/
 
 #ifndef BOTAN_ENTROPY_SRC_DEVICE_H__
 #define BOTAN_ENTROPY_SRC_DEVICE_H__
@@ -12,19 +12,15 @@
 
 namespace Botan {
 
-/*************************************************
-* Device Based Entropy Source                    *
-*************************************************/
 class BOTAN_DLL Device_EntropySource : public EntropySource
    {
    public:
       std::string name() const { return "RNG Device Reader"; }
 
+      void poll(Entropy_Accumulator& accum);
+
       Device_EntropySource(const std::vector<std::string>& fsnames);
       ~Device_EntropySource();
-
-      u32bit slow_poll(byte[], u32bit);
-      u32bit fast_poll(byte[], u32bit);
    private:
 
       /**
diff --git a/src/entropy/egd/es_egd.cpp b/src/entropy/egd/es_egd.cpp
index 84773c215..17e366f2b 100644
--- a/src/entropy/egd/es_egd.cpp
+++ b/src/entropy/egd/es_egd.cpp
@@ -1,6 +1,6 @@
-/**
+/*
 * EGD EntropySource Source File
-* (C) 1999-2008 Jack Lloyd
+* (C) 1999-2009 Jack Lloyd
 */
 
 #include <botan/es_egd.h>
@@ -8,6 +8,7 @@
 #include <botan/parsing.h>
 #include <botan/exceptn.h>
 #include <cstring>
+#include <stdexcept>
 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -23,28 +24,86 @@
 
 namespace Botan {
 
-EGD_EntropySource::EGD_Socket::EGD_Socket(const std::string& path)
+EGD_EntropySource::EGD_Socket::EGD_Socket(const std::string& path) :
+   socket_path(path), m_fd(-1)
    {
-   m_fd = ::socket(PF_LOCAL, SOCK_STREAM, 0);
+   }
 
-   if(m_fd > 0)
+/**
+* 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 Exception("EGD_EntropySource: Socket path is too long");
+         throw std::invalid_argument("EGD socket path is too long");
+
       std::strcpy(addr.sun_path, path.c_str());
 
       int len = sizeof(addr.sun_family) + std::strlen(addr.sun_path) + 1;
 
-      if(::connect(m_fd, reinterpret_cast<struct ::sockaddr*>(&addr), len) < 0)
+      if(::connect(fd, reinterpret_cast<struct ::sockaddr*>(&addr), len) < 0)
          {
-         ::close(m_fd);
-         m_fd = -1;
+         ::close(fd);
+         fd = -1;
          }
       }
+
+   return fd;
+   }
+
+/**
+* Attempt to read entropy from EGD
+*/
+u32bit EGD_EntropySource::EGD_Socket::read(byte outbuf[], u32bit 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<u32bit>(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 recieved 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<u32bit>(count);
+      }
+   catch(std::exception& e)
+      {
+      this->close();
+      // Will attempt to reopen next poll
+      }
+
+   return 0;
    }
 
 void EGD_EntropySource::EGD_Socket::close()
@@ -62,12 +121,7 @@ void EGD_EntropySource::EGD_Socket::close()
 EGD_EntropySource::EGD_EntropySource(const std::vector<std::string>& paths)
    {
    for(size_t i = 0; i != paths.size(); ++i)
-      {
-      EGD_Socket sock(paths[i]);
-
-      if(sock.fd() != -1)
-         sockets.push_back(sock);
-      }
+      sockets.push_back(EGD_Socket(paths[i]));
    }
 
 EGD_EntropySource::~EGD_EntropySource()
@@ -80,46 +134,22 @@ EGD_EntropySource::~EGD_EntropySource()
 /**
 * Gather Entropy from EGD
 */
-u32bit EGD_EntropySource::slow_poll(byte output[], u32bit length)
+void EGD_EntropySource::poll(Entropy_Accumulator& accum)
    {
-   if(length > 128)
-      length = 128;
+   u32bit go_get = std::min<u32bit>(accum.desired_remaining_bits() / 8, 32);
+
+   MemoryRegion<byte>& io_buffer = accum.get_io_buffer(go_get);
 
    for(size_t i = 0; i != sockets.size(); ++i)
       {
-      EGD_Socket& socket = sockets[i];
+      u32bit got = sockets[i].read(io_buffer.begin(), io_buffer.size());
 
-      byte buffer[2];
-      buffer[0] = 1;
-      buffer[1] = static_cast<byte>(length);
-
-      if(::write(socket.fd(), buffer, 2) != 2)
-         return 0;
-
-      byte out_len = 0;
-      if(::read(socket.fd(), &out_len, 1) != 1)
-         return 0;
-
-      if(out_len > length)
-         return 0;
-
-      ssize_t count = ::read(socket.fd(), output, out_len);
-
-      if(count < 0)
-         return 0;
-
-      return static_cast<u32bit>(count);
+      if(got)
+         {
+         accum.add(io_buffer.begin(), got, 8);
+         break;
+         }
       }
-
-   return 0;
-   }
-
-/**
-* Gather Entropy from EGD, limiting to 64 bytes
-*/
-u32bit EGD_EntropySource::fast_poll(byte output[], u32bit length)
-   {
-   return slow_poll(output, std::min<u32bit>(length, 64));
    }
 
 }
diff --git a/src/entropy/egd/es_egd.h b/src/entropy/egd/es_egd.h
index de80374cc..5fb09fc57 100644
--- a/src/entropy/egd/es_egd.h
+++ b/src/entropy/egd/es_egd.h
@@ -20,8 +20,7 @@ class BOTAN_DLL EGD_EntropySource : public EntropySource
    public:
       std::string name() const { return "EGD/PRNGD"; }
 
-      u32bit fast_poll(byte[], u32bit);
-      u32bit slow_poll(byte[], u32bit);
+      void poll(Entropy_Accumulator& accum);
 
       EGD_EntropySource(const std::vector<std::string>&);
       ~EGD_EntropySource();
@@ -32,9 +31,12 @@ class BOTAN_DLL EGD_EntropySource : public EntropySource
             EGD_Socket(const std::string& path);
 
             void close();
-            int fd() const { return m_fd; }
+            u32bit read(byte outbuf[], u32bit length);
          private:
-            int m_fd;
+            static int open_socket(const std::string& path);
+
+            std::string socket_path;
+            int m_fd; // cached fd
          };
 
       std::vector<EGD_Socket> sockets;
diff --git a/src/entropy/entropy_src.h b/src/entropy/entropy_src.h
index 0891e393f..3fd5c443e 100644
--- a/src/entropy/entropy_src.h
+++ b/src/entropy/entropy_src.h
@@ -1,26 +1,90 @@
-/*************************************************
-* EntropySource Header File                      *
-* (C) 2008 Jack Lloyd                            *
-*************************************************/
+/**
+* EntropySource Header File
+* (C) 2008-2009 Jack Lloyd
+*/
 
 #ifndef BOTAN_ENTROPY_SOURCE_BASE_H__
 #define BOTAN_ENTROPY_SOURCE_BASE_H__
 
-#include <botan/types.h>
+#include <botan/buf_comp.h>
 #include <string>
+#include <utility>
 
 namespace Botan {
 
 /**
+* Class used to accumulate the poll results of EntropySources
+*/
+class Entropy_Accumulator
+   {
+   public:
+      Entropy_Accumulator(u32bit goal) :
+         entropy_goal(goal), collected_bits(0) {}
+
+      virtual ~Entropy_Accumulator() {}
+
+      /**
+      @return cached I/O buffer for repeated polls
+      */
+      MemoryRegion<byte>& get_io_buffer(u32bit size)
+         { io_buffer.create(size); return io_buffer; }
+
+      u32bit bits_collected() const
+         { return static_cast<u32bit>(collected_bits); }
+
+      bool polling_goal_achieved() const
+         { return (collected_bits >= entropy_goal); }
+
+      u32bit desired_remaining_bits() const
+         {
+         if(collected_bits >= entropy_goal)
+            return 0;
+         return (entropy_goal - collected_bits);
+         }
+
+      void add(const void* bytes, u32bit length, double entropy_bits_per_byte)
+         {
+         add_bytes(bytes, length);
+         collected_bits += entropy_bits_per_byte * length;
+         }
+
+      template<typename T>
+      void add(const T& v, double entropy_bits_per_byte)
+         {
+         add(&v, sizeof(T), entropy_bits_per_byte);
+         }
+   private:
+      virtual void add_bytes(const void* bytes, u32bit length) = 0;
+
+      SecureVector<byte> io_buffer;
+      u32bit entropy_goal;
+      double collected_bits;
+   };
+
+class Entropy_Accumulator_BufferedComputation : public Entropy_Accumulator
+   {
+   public:
+      Entropy_Accumulator_BufferedComputation(BufferedComputation& sink,
+                                              u32bit goal) :
+         Entropy_Accumulator(goal), entropy_sink(sink) {}
+
+   private:
+      virtual void add_bytes(const void* bytes, u32bit length)
+         {
+         entropy_sink.update(reinterpret_cast<const byte*>(bytes), length);
+         }
+
+      BufferedComputation& entropy_sink;
+   };
+
+/**
 * Abstract interface to a source of (hopefully unpredictable) system entropy
 */
 class BOTAN_DLL EntropySource
    {
    public:
       virtual std::string name() const = 0;
-
-      virtual u32bit slow_poll(byte buf[], u32bit len) = 0;
-      virtual u32bit fast_poll(byte buf[], u32bit len) = 0;
+      virtual void poll(Entropy_Accumulator& accum) = 0;
       virtual ~EntropySource() {}
    };
 
diff --git a/src/entropy/proc_walk/es_ftw.cpp b/src/entropy/proc_walk/es_ftw.cpp
index 1ad6c56b6..55f26fa73 100644
--- a/src/entropy/proc_walk/es_ftw.cpp
+++ b/src/entropy/proc_walk/es_ftw.cpp
@@ -5,7 +5,6 @@
 
 #include <botan/es_ftw.h>
 #include <botan/secmem.h>
-#include <botan/xor_buf.h>
 #include <cstring>
 #include <deque>
 
@@ -110,49 +109,36 @@ FTW_EntropySource::~FTW_EntropySource()
    delete dir;
    }
 
-u32bit FTW_EntropySource::slow_poll(byte buf[], u32bit length)
+void FTW_EntropySource::poll(Entropy_Accumulator& accum)
    {
+   const u32bit MAX_FILES_READ_PER_POLL = 1024;
+
    if(!dir)
       dir = new Directory_Walker(path);
 
-   SecureVector<byte> read_buf(4096);
-
-   u32bit bytes_read = 0;
-   u32bit buf_i = 0;
+   MemoryRegion<byte>& io_buffer = accum.get_io_buffer(2048);
 
-   while(bytes_read < length * 32)
+   for(u32bit i = 0; i != MAX_FILES_READ_PER_POLL; ++i)
       {
       int fd = dir->next_fd();
 
-      if(fd == -1) // re-walk
+      // If we've exhaused this walk of the directory, halt the poll
+      if(fd == -1)
          {
          delete dir;
-         dir = new Directory_Walker(path);
-         fd = dir->next_fd();
-
-         if(fd == -1) // still fails (directory not mounted, etc) -> fail
-            return 0;
+         dir = 0;
+         break;
          }
 
-      ssize_t got = ::read(fd, read_buf.begin(), read_buf.size());
+      ssize_t got = ::read(fd, io_buffer.begin(), io_buffer.size());
+      ::close(fd);
 
       if(got > 0)
-         {
-         buf_i = xor_into_buf(buf, buf_i, length, read_buf, got);
-
-         // never count any one file for more than 128 bytes
-         bytes_read += std::min<u32bit>(got, 128);
-         }
+         accum.add(io_buffer.begin(), got, .01);
 
-      ::close(fd);
+      if(accum.polling_goal_achieved())
+         break;
       }
-
-   return length;
-   }
-
-u32bit FTW_EntropySource::fast_poll(byte[], u32bit)
-   {
-   return 0; // no op
    }
 
 }
diff --git a/src/entropy/proc_walk/es_ftw.h b/src/entropy/proc_walk/es_ftw.h
index 5b127943f..a764462c6 100644
--- a/src/entropy/proc_walk/es_ftw.h
+++ b/src/entropy/proc_walk/es_ftw.h
@@ -10,16 +10,15 @@
 
 namespace Botan {
 
-/*************************************************
-* File Tree Walking Entropy Source               *
-*************************************************/
+/**
+* File Tree Walking Entropy Source
+*/
 class BOTAN_DLL FTW_EntropySource : public EntropySource
    {
    public:
       std::string name() const { return "Proc Walker"; }
 
-      u32bit slow_poll(byte buf[], u32bit len);
-      u32bit fast_poll(byte buf[], u32bit len);
+      void poll(Entropy_Accumulator& accum);
 
       FTW_EntropySource(const std::string& root_dir);
       ~FTW_EntropySource();
diff --git a/src/entropy/unix_procs/es_unix.cpp b/src/entropy/unix_procs/es_unix.cpp
index 124a08da7..3ac8cd8d3 100644
--- a/src/entropy/unix_procs/es_unix.cpp
+++ b/src/entropy/unix_procs/es_unix.cpp
@@ -1,12 +1,11 @@
-/*************************************************
-* Unix EntropySource Source File                 *
-* (C) 1999-2008 Jack Lloyd                       *
-*************************************************/
+/*
+* Unix EntropySource Source File
+* (C) 1999-2009 Jack Lloyd
+*/
 
 #include <botan/es_unix.h>
 #include <botan/unix_cmd.h>
 #include <botan/parsing.h>
-#include <botan/xor_buf.h>
 #include <algorithm>
 #include <sys/time.h>
 #include <sys/stat.h>
@@ -17,43 +16,40 @@ namespace Botan {
 
 namespace {
 
-/*************************************************
-* Sort ordering by priority                      *
-*************************************************/
+/**
+* Sort ordering by priority
+*/
 bool Unix_Program_Cmp(const Unix_Program& a, const Unix_Program& b)
    { return (a.priority < b.priority); }
 
 }
 
-/*************************************************
-* Unix_EntropySource Constructor                 *
-*************************************************/
+/**
+* Unix_EntropySource Constructor
+*/
 Unix_EntropySource::Unix_EntropySource(const std::vector<std::string>& path) :
    PATH(path)
    {
    add_default_sources(sources);
    }
 
-/*************************************************
-* Add sources to the list                        *
-*************************************************/
+/**
+* Add sources to the list
+*/
 void Unix_EntropySource::add_sources(const Unix_Program srcs[], u32bit count)
    {
    sources.insert(sources.end(), srcs, srcs + count);
    std::sort(sources.begin(), sources.end(), Unix_Program_Cmp);
    }
 
-/*************************************************
-* Unix Fast Poll                                 *
-*************************************************/
-u32bit Unix_EntropySource::fast_poll(byte buf[], u32bit length)
+/**
+* Poll for entropy on a generic Unix system, first by grabbing various
+* statistics (stat on common files, getrusage, etc), and then, if more
+* is required, by exec'ing various programs like uname and rpcinfo and
+* reading the output.
+*/
+void Unix_EntropySource::poll(Entropy_Accumulator& accum)
    {
-   if(length == 0)
-      return 0;
-   length = std::min<u32bit>(length, 32);
-
-   u32bit buf_i = 0;
-
    const char* stat_targets[] = {
       "/",
       "/tmp",
@@ -70,67 +66,50 @@ u32bit Unix_EntropySource::fast_poll(byte buf[], u32bit length)
       struct stat statbuf;
       clear_mem(&statbuf, 1);
       ::stat(stat_targets[j], &statbuf);
-      buf_i = xor_into_buf(buf, buf_i, length, statbuf);
+      accum.add(&statbuf, sizeof(statbuf), .05);
       }
 
-   u32bit ids[] = {
-      ::getpid(),
-      ::getppid(),
-      ::getuid(),
-      ::geteuid(),
-      ::getegid(),
-      ::getpgrp(),
-      ::getsid(0)
-   };
-
-   for(u32bit i = 0; i != sizeof(ids) / sizeof(ids[0]); ++i)
-      buf_i = xor_into_buf(buf, buf_i, length, ids[i]);
+   accum.add(::getpid(),  0);
+   accum.add(::getppid(), 0);
+   accum.add(::getuid(),  0);
+   accum.add(::geteuid(), 0);
+   accum.add(::getegid(), 0);
+   accum.add(::getpgrp(), 0);
+   accum.add(::getsid(0), 0);
 
    struct ::rusage usage;
    ::getrusage(RUSAGE_SELF, &usage);
-   buf_i = xor_into_buf(buf, buf_i, length, usage);
+   accum.add(usage, .05);
 
    ::getrusage(RUSAGE_CHILDREN, &usage);
-   buf_i = xor_into_buf(buf, buf_i, length, usage);
-
-   return length;
-   }
+   accum.add(usage, .05);
 
-/*************************************************
-* Unix Slow Poll                                 *
-*************************************************/
-u32bit Unix_EntropySource::slow_poll(byte buf[], u32bit length)
-   {
-   if(length == 0)
-      return 0;
+   if(accum.desired_remaining_bits() < 128)
+      return;
 
-   const u32bit MINIMAL_WORKING = 32;
+   const u32bit MINIMAL_WORKING = 16;
 
-   u32bit total_got = 0;
-   u32bit buf_i = 0;
+   MemoryRegion<byte>& io_buffer = accum.get_io_buffer(DEFAULT_BUFFERSIZE);
 
    for(u32bit j = 0; j != sources.size(); j++)
       {
       DataSource_Command pipe(sources[j].name_and_args, PATH);
-      SecureVector<byte> buffer(DEFAULT_BUFFERSIZE);
 
       u32bit got_from_src = 0;
 
       while(!pipe.end_of_data())
          {
-         u32bit this_loop = pipe.read(buffer, buffer.size());
-         buf_i = xor_into_buf(buf, buf_i, length, buffer, this_loop);
-         got_from_src += this_loop;
+         u32bit got_this_loop = pipe.read(io_buffer, io_buffer.size());
+         got_from_src += got_this_loop;
+
+         accum.add(io_buffer.begin(), got_this_loop, .005);
          }
 
       sources[j].working = (got_from_src >= MINIMAL_WORKING) ? true : false;
-      total_got += got_from_src;
 
-      if(total_got >= 128*length)
+      if(accum.polling_goal_achieved())
          break;
       }
-
-   return length;
    }
 
 }
diff --git a/src/entropy/unix_procs/es_unix.h b/src/entropy/unix_procs/es_unix.h
index f4af255ca..ba3fd51c2 100644
--- a/src/entropy/unix_procs/es_unix.h
+++ b/src/entropy/unix_procs/es_unix.h
@@ -1,7 +1,7 @@
-/*************************************************
-* Unix EntropySource Header File                 *
-* (C) 1999-2007 Jack Lloyd                       *
-*************************************************/
+/*
+* Unix EntropySource Header File
+* (C) 1999-2009 Jack Lloyd
+*/
 
 #ifndef BOTAN_ENTROPY_SRC_UNIX_H__
 #define BOTAN_ENTROPY_SRC_UNIX_H__
@@ -12,21 +12,21 @@
 
 namespace Botan {
 
-/*************************************************
-* Unix Entropy Source                            *
-*************************************************/
+/**
+* Unix Entropy Source
+*/
 class BOTAN_DLL Unix_EntropySource : public EntropySource
    {
    public:
       std::string name() const { return "Unix Entropy Source"; }
 
+      void poll(Entropy_Accumulator& accum);
+
       void add_sources(const Unix_Program[], u32bit);
       Unix_EntropySource(const std::vector<std::string>& path);
    private:
       static void add_default_sources(std::vector<Unix_Program>&);
-
-      u32bit fast_poll(byte buf[], u32bit length);
-      u32bit slow_poll(byte buf[], u32bit length);
+      void fast_poll(Entropy_Accumulator& accum);
 
       const std::vector<std::string> PATH;
       std::vector<Unix_Program> sources;
diff --git a/src/entropy/unix_procs/unix_cmd.cpp b/src/entropy/unix_procs/unix_cmd.cpp
index 4c7f674db..b9558b35c 100644
--- a/src/entropy/unix_procs/unix_cmd.cpp
+++ b/src/entropy/unix_procs/unix_cmd.cpp
@@ -1,7 +1,7 @@
-/*************************************************
-* Unix Command Execution Source File             *
-* (C) 1999-2007 Jack Lloyd                       *
-*************************************************/
+/*
+* Unix Command Execution Source File
+* (C) 1999-2007 Jack Lloyd
+*/
 
 #include <botan/unix_cmd.h>
 #include <botan/parsing.h>
@@ -18,9 +18,9 @@ namespace Botan {
 
 namespace {
 
-/*************************************************
-* Attempt to execute the command                 *
-************************************************/
+/**
+* Attempt to execute the command
+*/
 void do_exec(const std::vector<std::string>& arg_list,
              const std::vector<std::string>& paths)
    {
@@ -41,9 +41,9 @@ void do_exec(const std::vector<std::string>& arg_list,
 
 }
 
-/*************************************************
-* Local information about the pipe               *
-*************************************************/
+/**
+* Local information about the pipe
+*/
 struct pipe_wrapper
    {
    int fd;
@@ -51,9 +51,9 @@ struct pipe_wrapper
    pipe_wrapper() { fd = -1; pid = 0; }
    };
 
-/*************************************************
-* Read from the pipe                             *
-*************************************************/
+/**
+* Read from the pipe
+*/
 u32bit DataSource_Command::read(byte buf[], u32bit length)
    {
    if(end_of_data())
@@ -83,9 +83,9 @@ u32bit DataSource_Command::read(byte buf[], u32bit length)
    return static_cast<u32bit>(got);
    }
 
-/*************************************************
-* Peek at the pipe contents                      *
-*************************************************/
+/**
+* Peek at the pipe contents
+*/
 u32bit DataSource_Command::peek(byte[], u32bit, u32bit) const
    {
    if(end_of_data())
@@ -93,17 +93,17 @@ u32bit DataSource_Command::peek(byte[], u32bit, u32bit) const
    throw Stream_IO_Error("Cannot peek/seek on a command pipe");
    }
 
-/*************************************************
-* Check if we reached EOF                        *
-*************************************************/
+/**
+* Check if we reached EOF
+*/
 bool DataSource_Command::end_of_data() const
    {
    return (pipe) ? false : true;
    }
 
-/*************************************************
-* Return the Unix file descriptor of the pipe    *
-*************************************************/
+/**
+* Return the Unix file descriptor of the pipe
+*/
 int DataSource_Command::fd() const
    {
    if(!pipe)
@@ -111,17 +111,17 @@ int DataSource_Command::fd() const
    return pipe->fd;
    }
 
-/*************************************************
-* Return a human-readable ID for this stream     *
-*************************************************/
+/**
+* Return a human-readable ID for this stream
+*/
 std::string DataSource_Command::id() const
    {
    return "Unix command: " + arg_list[0];
    }
 
-/*************************************************
-* Create the pipe                                *
-*************************************************/
+/**
+* Create the pipe
+*/
 void DataSource_Command::create_pipe(const std::vector<std::string>& paths)
    {
    bool found_something = false;
@@ -169,9 +169,9 @@ void DataSource_Command::create_pipe(const std::vector<std::string>& paths)
       }
    }
 
-/*************************************************
-* Shutdown the pipe                              *
-*************************************************/
+/**
+* Shutdown the pipe
+*/
 void DataSource_Command::shutdown_pipe()
    {
    if(pipe)
@@ -204,9 +204,9 @@ void DataSource_Command::shutdown_pipe()
       }
    }
 
-/*************************************************
-* DataSource_Command Constructor                 *
-*************************************************/
+/**
+* DataSource_Command Constructor
+*/
 DataSource_Command::DataSource_Command(const std::string& prog_and_args,
                                        const std::vector<std::string>& paths) :
    MAX_BLOCK_USECS(100000), KILL_WAIT(10000)
@@ -222,9 +222,9 @@ DataSource_Command::DataSource_Command(const std::string& prog_and_args,
    create_pipe(paths);
    }
 
-/*************************************************
-* DataSource_Command Destructor                  *
-*************************************************/
+/**
+* DataSource_Command Destructor
+*/
 DataSource_Command::~DataSource_Command()
    {
    if(!end_of_data())
diff --git a/src/entropy/unix_procs/unix_cmd.h b/src/entropy/unix_procs/unix_cmd.h
index 8544e7879..66122ea49 100644
--- a/src/entropy/unix_procs/unix_cmd.h
+++ b/src/entropy/unix_procs/unix_cmd.h
@@ -1,7 +1,7 @@
-/*************************************************
-* Unix Command Execution Header File             *
-* (C) 1999-2007 Jack Lloyd                       *
-*************************************************/
+/**
+* Unix Command Execution Header File
+* (C) 1999-2007 Jack Lloyd
+*/
 
 #ifndef BOTAN_UNIX_CMD_H__
 #define BOTAN_UNIX_CMD_H__
@@ -13,9 +13,9 @@
 
 namespace Botan {
 
-/*************************************************
-* Unix Program Info                              *
-*************************************************/
+/**
+* Unix Program Info
+*/
 struct Unix_Program
    {
    Unix_Program(const char* n, u32bit p)
@@ -26,9 +26,9 @@ struct Unix_Program
    bool working;
    };
 
-/*************************************************
-* Command Output DataSource                      *
-*************************************************/
+/**
+* Command Output DataSource
+*/
 class BOTAN_DLL DataSource_Command : public DataSource
    {
    public:
diff --git a/src/entropy/unix_procs/unix_src.cpp b/src/entropy/unix_procs/unix_src.cpp
index 9d44dbf4f..5e48ba41d 100644
--- a/src/entropy/unix_procs/unix_src.cpp
+++ b/src/entropy/unix_procs/unix_src.cpp
@@ -1,15 +1,15 @@
-/*************************************************
-* Program List for Unix_EntropySource            *
-* (C) 1999-2007 Jack Lloyd                       *
-*************************************************/
+/*
+* Program List for Unix_EntropySource
+* (C) 1999-2007 Jack Lloyd
+*/
 
 #include <botan/es_unix.h>
 
 namespace Botan {
 
-/*************************************************
-* Default Commands for Entropy Gathering         *
-*************************************************/
+/**
+* Default Commands for Entropy Gathering
+*/
 void Unix_EntropySource::add_default_sources(std::vector<Unix_Program>& srcs)
    {
    srcs.push_back(Unix_Program("vmstat",                1));
diff --git a/src/entropy/win32_stats/es_win32.cpp b/src/entropy/win32_stats/es_win32.cpp
index a529ccc1a..0c17f7b02 100644
--- a/src/entropy/win32_stats/es_win32.cpp
+++ b/src/entropy/win32_stats/es_win32.cpp
@@ -1,43 +1,69 @@
 /**
 * Win32 EntropySource Source File
-* (C) 1999-2008 Jack Lloyd
+* (C) 1999-2009 Jack Lloyd
 */
 
 #include <botan/es_win32.h>
-#include <botan/xor_buf.h>
 #include <windows.h>
 #include <tlhelp32.h>
 
 namespace Botan {
 
 /**
-* Win32 slow poll using Tooltip32
+* Win32 poll using stats functions including Tooltip32
 */
-u32bit Win32_EntropySource::slow_poll(byte buf[], u32bit length)
+void Win32_EntropySource::poll(Entropy_Accumulator& accum)
    {
-   if(length == 0)
-      return 0;
+   /*
+   First query a bunch of basic statistical stuff, though
+   don't count it for much in terms of contributed entropy.
+   */
+   accum.add(GetTickCount(), 0);
+   accum.add(GetMessagePos(), 0);
+   accum.add(GetMessageTime(), 0);
+   accum.add(GetInputState(), 0);
+   accum.add(GetCurrentProcessId(), 0);
+   accum.add(GetCurrentThreadId() 0);
 
-   const u32bit MAX_ITEMS = length / 4;
+   SYSTEM_INFO sys_info;
+   GetSystemInfo(&sys_info);
+   accum.add(sys_info, 1);
+
+   MEMORYSTATUS mem_info;
+   GlobalMemoryStatus(&mem_info);
+   accum.add(mem_info, 1);
+
+   POINT point;
+   GetCursorPos(&point);
+   accum.add(point, 1);
+
+   GetCaretPos(&point);
+   accum.add(point, 1);
+
+   LARGE_INTEGER perf_counter;
+   QueryPerformanceCounter(&perf_counter);
+   accum.add(perf_count, 0);
 
-   u32bit buf_i = 0;
+   /*
+   Now use the Tooltip library to iterate throug various objects on
+   the system, including processes, threads, and heap objects.
+   */
 
    HANDLE snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPALL, 0);
 
 #define TOOLHELP32_ITER(DATA_TYPE, FUNC_FIRST, FUNC_NEXT) \
-   {                                                      \
-   u32bit items = 0;                                      \
-   DATA_TYPE info;                                        \
-   info.dwSize = sizeof(DATA_TYPE);                       \
-   if(FUNC_FIRST(snapshot, &info))                        \
+   if(!accum.polling_goal_achieved())                     \
       {                                                   \
-      do                                                  \
+      DATA_TYPE info;                                     \
+      info.dwSize = sizeof(DATA_TYPE);                    \
+      if(FUNC_FIRST(snapshot, &info))                     \
          {                                                \
-         if(items++ > MAX_ITEMS) break;                   \
-         buf_i = xor_into_buf(buf, buf_i, length, info);  \
-         } while(FUNC_NEXT(snapshot, &info));             \
-      }                                                   \
-   }
+         do                                               \
+            {                                             \
+            accum.add(info, 1);                           \
+            } while(FUNC_NEXT(snapshot, &info));          \
+         }                                                \
+      }
 
    TOOLHELP32_ITER(MODULEENTRY32, Module32First, Module32Next);
    TOOLHELP32_ITER(PROCESSENTRY32, Process32First, Process32Next);
@@ -45,85 +71,46 @@ u32bit Win32_EntropySource::slow_poll(byte buf[], u32bit length)
 
 #undef TOOLHELP32_ITER
 
-   u32bit heap_lists_found = 0;
-   HEAPLIST32 heap_list;
-   heap_list.dwSize = sizeof(HEAPLIST32);
-
-   const u32bit HEAP_LISTS_MAX = 32;
-   const u32bit HEAP_OBJS_PER_LIST = 128;
-   if(Heap32ListFirst(snapshot, &heap_list))
+   if(!accum.polling_goal_achieved())
       {
-      do
-         {
-         buf_i = xor_into_buf(buf, buf_i, length, heap_list);
+      u32bit heap_lists_found = 0;
+      HEAPLIST32 heap_list;
+      heap_list.dwSize = sizeof(HEAPLIST32);
 
-         if(heap_lists_found++ > HEAP_LISTS_MAX)
-            break;
+      const u32bit HEAP_LISTS_MAX = 32;
+      const u32bit HEAP_OBJS_PER_LIST = 128;
 
-         u32bit heap_objs_found = 0;
-         HEAPENTRY32 heap_entry;
-         heap_entry.dwSize = sizeof(HEAPENTRY32);
-         if(Heap32First(&heap_entry, heap_list.th32ProcessID,
-                                     heap_list.th32HeapID))
+      if(Heap32ListFirst(snapshot, &heap_list))
+         {
+         do
             {
-            do
+            accum.add(heap_list, 1);
+
+            if(++heap_lists_found > HEAP_LISTS_MAX)
+               break;
+
+            u32bit heap_objs_found = 0;
+            HEAPENTRY32 heap_entry;
+            heap_entry.dwSize = sizeof(HEAPENTRY32);
+            if(Heap32First(&heap_entry, heap_list.th32ProcessID,
+                           heap_list.th32HeapID))
                {
-               if(heap_objs_found++ > HEAP_OBJS_PER_LIST)
-                  break;
-               buf_i = xor_into_buf(buf, buf_i, length, heap_entry);
-               } while(Heap32Next(&heap_entry));
-            }
-         } while(Heap32ListNext(snapshot, &heap_list));
+               do
+                  {
+                  if(heap_objs_found++ > HEAP_OBJS_PER_LIST)
+                     break;
+                  accum.add(heap_entry, 1);
+                  } while(Heap32Next(&heap_entry));
+               }
+
+            if(accum.polling_goal_achieved())
+               break;
+
+            } while(Heap32ListNext(snapshot, &heap_list));
+         }
       }
 
    CloseHandle(snapshot);
-
-   return length;
-   }
-
-/**
-* Win32 fast poll
-*/
-u32bit Win32_EntropySource::fast_poll(byte buf[], u32bit length)
-   {
-   if(length == 0)
-      return 0;
-   length = std::min<u32bit>(length, 32);
-
-   u32bit buf_i = 0;
-
-   u32bit stats[] = {
-      GetTickCount(),
-      GetMessagePos(),
-      GetMessageTime(),
-      GetInputState(),
-      GetCurrentProcessId(),
-      GetCurrentThreadId()
-   };
-
-   for(u32bit i = 0; i != sizeof(stats) / sizeof(stats[0]); ++i)
-      buf_i = xor_into_buf(buf, buf_i, length, stats[i]);
-
-   SYSTEM_INFO sys_info;
-   GetSystemInfo(&sys_info);
-   buf_i = xor_into_buf(buf, buf_i, length, sys_info);
-
-   MEMORYSTATUS mem_info;
-   GlobalMemoryStatus(&mem_info);
-   buf_i = xor_into_buf(buf, buf_i, length, mem_info);
-
-   POINT point;
-   GetCursorPos(&point);
-   buf_i = xor_into_buf(buf, buf_i, length, point);
-
-   GetCaretPos(&point);
-   buf_i = xor_into_buf(buf, buf_i, length, point);
-
-   LARGE_INTEGER perf_counter;
-   QueryPerformanceCounter(&perf_counter);
-   buf_i = xor_into_buf(buf, buf_i, length, perf_counter);
-
-   return length;
    }
 
 }
diff --git a/src/entropy/win32_stats/es_win32.h b/src/entropy/win32_stats/es_win32.h
index 3124bd414..06e3b88cc 100644
--- a/src/entropy/win32_stats/es_win32.h
+++ b/src/entropy/win32_stats/es_win32.h
@@ -1,6 +1,6 @@
 /**
 * Win32 EntropySource Header File
-* (C) 1999-2008 Jack Lloyd
+* (C) 1999-2009 Jack Lloyd
 */
 
 #ifndef BOTAN_ENTROPY_SRC_WIN32_H__
@@ -17,9 +17,7 @@ class BOTAN_DLL Win32_EntropySource : public EntropySource
    {
    public:
       std::string name() const { return "Win32 Statistics"; }
-
-      u32bit fast_poll(byte buf[], u32bit length);
-      u32bit slow_poll(byte buf[], u32bit length);
+      void poll(Entropy_Accumulator& accum);
    };
 
 }
diff --git a/src/rng/auto_rng/auto_rng.cpp b/src/rng/auto_rng/auto_rng.cpp
index 845d958e2..620cc1f61 100644
--- a/src/rng/auto_rng/auto_rng.cpp
+++ b/src/rng/auto_rng/auto_rng.cpp
@@ -76,19 +76,15 @@ namespace {
 */
 void add_entropy_sources(RandomNumberGenerator* rng)
    {
+
+   // Add a high resolution timer, if available
 #if defined(BOTAN_HAS_TIMER_HARDWARE)
    rng->add_entropy_source(new Hardware_Timer);
-#endif
-
-#if defined(BOTAN_HAS_TIMER_POSIX)
+#elif defined(BOTAN_HAS_TIMER_POSIX)
    rng->add_entropy_source(new POSIX_Timer);
-#endif
-
-#if defined(BOTAN_HAS_TIMER_UNIX)
+#elif defined(BOTAN_HAS_TIMER_UNIX)
    rng->add_entropy_source(new Unix_Timer);
-#endif
-
-#if defined(BOTAN_HAS_TIMER_WIN32)
+#elif defined(BOTAN_HAS_TIMER_WIN32)
    rng->add_entropy_source(new Win32_Timer);
 #endif
 
@@ -114,7 +110,6 @@ void add_entropy_sources(RandomNumberGenerator* rng)
    rng->add_entropy_source(new FTW_EntropySource("/proc"));
 #endif
 
-
 #if defined(BOTAN_HAS_ENTROPY_SRC_WIN32)
    rng->add_entropy_source(new Win32_EntropySource);
 #endif
@@ -132,7 +127,7 @@ void add_entropy_sources(RandomNumberGenerator* rng)
 
 }
 
-AutoSeeded_RNG::AutoSeeded_RNG()
+AutoSeeded_RNG::AutoSeeded_RNG(u32bit poll_bits)
    {
    rng = 0;
 
@@ -152,7 +147,7 @@ AutoSeeded_RNG::AutoSeeded_RNG()
 
    add_entropy_sources(rng);
 
-   rng->reseed();
+   rng->reseed(poll_bits);
    }
 
 }
diff --git a/src/rng/auto_rng/auto_rng.h b/src/rng/auto_rng/auto_rng.h
index dea735470..5536f2b8e 100644
--- a/src/rng/auto_rng/auto_rng.h
+++ b/src/rng/auto_rng/auto_rng.h
@@ -25,13 +25,13 @@ class BOTAN_DLL AutoSeeded_RNG : public RandomNumberGenerator
       std::string name() const
          { return "AutoSeeded(" + rng->name() + ")"; }
 
-      void reseed() { rng->reseed(); }
+      void reseed(u32bit poll_bits) { rng->reseed(poll_bits); }
       void add_entropy_source(EntropySource* es)
          { rng->add_entropy_source(es); }
       void add_entropy(const byte in[], u32bit len)
          { rng->add_entropy(in, len); }
 
-      AutoSeeded_RNG();
+      AutoSeeded_RNG(u32bit poll_bits = 256);
       ~AutoSeeded_RNG() { delete rng; }
    private:
       RandomNumberGenerator* rng;
diff --git a/src/rng/hmac_rng/hmac_rng.cpp b/src/rng/hmac_rng/hmac_rng.cpp
index 188c32689..458118e11 100644
--- a/src/rng/hmac_rng/hmac_rng.cpp
+++ b/src/rng/hmac_rng/hmac_rng.cpp
@@ -1,7 +1,7 @@
-/*************************************************
-* HMAC_RNG Source File                           *
-* (C) 2008 Jack Lloyd                            *
-*************************************************/
+/*
+* HMAC_RNG
+* (C) 2008-2009 Jack Lloyd
+*/
 
 #include <botan/hmac_rng.h>
 #include <botan/loadstor.h>
@@ -16,9 +16,9 @@ namespace Botan {
 namespace {
 
 void hmac_prf(MessageAuthenticationCode* prf,
-            MemoryRegion<byte>& K,
-            u32bit& counter,
-            const std::string& label)
+              MemoryRegion<byte>& K,
+              u32bit& counter,
+              const std::string& label)
    {
    prf->update(K, K.size());
    prf->update(label);
@@ -31,24 +31,13 @@ void hmac_prf(MessageAuthenticationCode* prf,
 
 }
 
-/*************************************************
-* Generate a buffer of random bytes              *
-*************************************************/
+/**
+* Generate a buffer of random bytes
+*/
 void HMAC_RNG::randomize(byte out[], u32bit length)
    {
-   /* Attempt to seed if we are currently not seeded, or if the
-      counter is greater than 2^20
-
-      If HMAC_RNG is wrapped in an X9.31/AES PRNG (the default), this
-      means a reseed will be kicked off every 16 MiB of RNG output.
-   */
-   if(!is_seeded() || counter >= 0x100000)
-      {
-      reseed();
-
-      if(!is_seeded())
-         throw PRNG_Unseeded(name() + " seeding attempt failed");
-      }
+   if(!is_seeded())
+      throw PRNG_Unseeded(name());
 
    /*
     HMAC KDF as described in E-t-E, using a CTXinfo of "rng"
@@ -63,94 +52,43 @@ void HMAC_RNG::randomize(byte out[], u32bit length)
       out += copied;
       length -= copied;
       }
-
-   /* Every once in a while do a fast poll of a entropy source */
-   if(entropy_sources.size() && (counter % 65536 == 0))
-      {
-      u32bit got = entropy_sources.at(source_index)->
-                       fast_poll(io_buffer, io_buffer.size());
-
-      source_index = (source_index + 1) % entropy_sources.size();
-      extractor->update(io_buffer, got);
-      io_buffer.clear();
-      }
    }
 
 /**
 * Reseed the internal state, also accepting user input to include
 */
-void HMAC_RNG::reseed_with_input(const byte input[], u32bit input_length)
+void HMAC_RNG::reseed_with_input(u32bit poll_bits,
+                                 const byte input[], u32bit input_length)
    {
-   if(entropy_sources.size())
+   /**
+   Using the terminology of E-t-E, XTR is the MAC function (normally
+   HMAC) seeded with XTS (below) and we form SKM, the key material, by
+   fast polling each source, and then slow polling as many as we think
+   we need (in the following loop), and feeding all of the poll
+   results, along with any optional user input, along with, finally,
+   feedback of the current PRK value, into the extractor function.
+   */
+
+   Entropy_Accumulator_BufferedComputation accum(*extractor, poll_bits);
+
+   for(u32bit i = 0; i < entropy_sources.size(); ++i)
       {
-      /**
-      Using the terminology of E-t-E, XTR is the MAC function (normally
-      HMAC) seeded with XTS (below) and we form SKM, the key material, by
-      fast polling each source, and then slow polling as many as we think
-      we need (in the following loop), and feeding all of the poll
-      results, along with any optional user input, along with, finally,
-      feedback of the current PRK value, into the extractor function.
-      */
-
-      /*
-      Previously this function did entropy estimation. However the paper
-
-      "Boaz Barak, Shai Halevi: A model and architecture for
-       pseudo-random generation with applications to /dev/random. ACM
-       Conference on Computer and Communications Security 2005."
-
-      provides a pretty strong case to not even try, since what we are
-      really interested in is the *conditional* entropy from the point
-      of view of an unknown attacker, which is impossible to
-      calculate. They recommend, if an entropy estimate of some kind
-      is needed, to use a low static estimate instead. We use here an
-      estimate of 1 bit per byte.
-
-      One thing I had been concerned about initially was that people
-      without any randomness source enabled (much more likely in the
-      days when you had to enable them manually) would find the RNG
-      was unseeded and then pull the manuever some OpenSSL users did
-      and seed the RNG with a constant string. However, upon further
-      thought, I've decided that people who do that deserve to lose
-      anyway.
-      */
-
-      for(u32bit j = 0; j < entropy_sources.size(); ++j)
-         {
-         const u32bit got =
-            entropy_sources[j]->fast_poll(io_buffer, io_buffer.size());
-
-         entropy += got;
-         extractor->update(io_buffer, got);
-         io_buffer.clear();
-         }
-
-      for(u32bit j = 0; j != entropy_sources.size(); ++j)
-         {
-         const u32bit got =
-            entropy_sources[j]->slow_poll(io_buffer, io_buffer.size());
-
-         entropy += got;
-         extractor->update(io_buffer, got);
-         io_buffer.clear();
-         }
+      if(accum.polling_goal_achieved())
+         break;
+
+      entropy_sources[i]->poll(accum);
       }
 
-   /*
-   And now add the user-provided input, if any
-   */
+   // And now add the user-provided input, if any
    if(input_length)
-      {
-      extractor->update(input, input_length);
-      entropy += input_length;
-      }
+      accum.add(input, input_length, 1);
 
    /*
-   It is necessary to feed forward poll data. Otherwise, a good
-   poll (collecting a large amount of conditional entropy) followed
-   by a bad one (collecting little) would be unsafe. Do this by
-   generating new PRF outputs using the previous key and feeding them
-   into the extractor function.
+   It is necessary to feed forward poll data. Otherwise, a good poll
+   (collecting a large amount of conditional entropy) followed by a
+   bad one (collecting little) would be unsafe. Do this by generating
+   new PRF outputs using the previous key and feeding them into the
+   extractor function.
 
    Cycle the RNG once (CTXinfo="rng"), then generate a new PRF output
    using the CTXinfo "reseed". Provide these values as input to the
@@ -174,77 +112,66 @@ void HMAC_RNG::reseed_with_input(const byte input[], u32bit input_length)
    K.clear();
    counter = 0;
 
-   // Upper bound entropy estimate at the extractor output size
-   entropy = std::min<u32bit>(entropy, 8 * extractor->OUTPUT_LENGTH);
+   if(input_length || accum.bits_collected() >= poll_bits)
+      seeded = true;
    }
 
 /**
 * Reseed the internal state
 */
-void HMAC_RNG::reseed()
+void HMAC_RNG::reseed(u32bit poll_bits)
    {
-   reseed_with_input(0, 0);
+   reseed_with_input(poll_bits, 0, 0);
    }
 
 /**
-Add user-supplied entropy by reseeding and including this
-input among the poll data
+* Add user-supplied entropy by reseeding and including this
+* input among the poll data
 */
 void HMAC_RNG::add_entropy(const byte input[], u32bit length)
    {
-   reseed_with_input(input, length);
+   reseed_with_input(0, input, length);
    }
 
-/*************************************************
-* Add another entropy source to the list         *
-*************************************************/
+/**
+* Add another entropy source to the list
+*/
 void HMAC_RNG::add_entropy_source(EntropySource* src)
    {
    entropy_sources.push_back(src);
    }
 
-/*************************************************
-* Check if the the pool is seeded                *
-*************************************************/
-bool HMAC_RNG::is_seeded() const
-   {
-   return (entropy >= 8 * prf->OUTPUT_LENGTH);
-   }
-
- /*************************************************
-* Clear memory of sensitive data                 *
-*************************************************/
+/*
+* Clear memory of sensitive data
+*/
 void HMAC_RNG::clear() throw()
    {
    extractor->clear();
    prf->clear();
    K.clear();
-   entropy = 0;
    counter = 0;
-   source_index = 0;
+   seeded = false;
    }
 
-/*************************************************
-* Return the name of this type                   *
-*************************************************/
+/**
+* Return the name of this type
+*/
 std::string HMAC_RNG::name() const
    {
    return "HMAC_RNG(" + extractor->name() + "," + prf->name() + ")";
    }
 
-/*************************************************
-* HMAC_RNG Constructor                           *
-*************************************************/
+/**
+* HMAC_RNG Constructor
+*/
 HMAC_RNG::HMAC_RNG(MessageAuthenticationCode* extractor_mac,
                    MessageAuthenticationCode* prf_mac) :
-   extractor(extractor_mac), prf(prf_mac), io_buffer(96)
+   extractor(extractor_mac), prf(prf_mac)
    {
-   entropy = 0;
-
    // First PRF inputs are all zero, as specified in section 2
    K.create(prf->OUTPUT_LENGTH);
    counter = 0;
-   source_index = 0;
+   seeded = false;
 
    /*
    Normally we want to feedback PRF output into the input to the
@@ -275,9 +202,9 @@ HMAC_RNG::HMAC_RNG(MessageAuthenticationCode* extractor_mac,
                       xts.length());
    }
 
-/*************************************************
-* HMAC_RNG Destructor                            *
-*************************************************/
+/**
+* HMAC_RNG Destructor
+*/
 HMAC_RNG::~HMAC_RNG()
    {
    delete extractor;
@@ -286,7 +213,6 @@ HMAC_RNG::~HMAC_RNG()
    std::for_each(entropy_sources.begin(), entropy_sources.end(),
                  del_fun<EntropySource>());
 
-   entropy = 0;
    counter = 0;
    }
 
diff --git a/src/rng/hmac_rng/hmac_rng.h b/src/rng/hmac_rng/hmac_rng.h
index b9ea064c3..16adddd60 100644
--- a/src/rng/hmac_rng/hmac_rng.h
+++ b/src/rng/hmac_rng/hmac_rng.h
@@ -1,7 +1,7 @@
-/*************************************************
-* HMAC RNG                                       *
-* (C) 2008 Jack Lloyd                            *
-*************************************************/
+/*
+* HMAC RNG
+* (C) 2008 Jack Lloyd
+*/
 
 #ifndef BOTAN_HMAC_RNG_H__
 #define BOTAN_HMAC_RNG_H__
@@ -26,11 +26,11 @@ class BOTAN_DLL HMAC_RNG : public RandomNumberGenerator
    {
    public:
       void randomize(byte buf[], u32bit len);
-      bool is_seeded() const;
+      bool is_seeded() const { return seeded; }
       void clear() throw();
       std::string name() const;
 
-      void reseed();
+      void reseed(u32bit poll_bits);
       void add_entropy_source(EntropySource* es);
       void add_entropy(const byte[], u32bit);
 
@@ -39,13 +39,14 @@ class BOTAN_DLL HMAC_RNG : public RandomNumberGenerator
 
       ~HMAC_RNG();
    private:
-      void reseed_with_input(const byte input[], u32bit length);
+      void reseed_with_input(u32bit poll_bits,
+                             const byte input[], u32bit length);
 
       MessageAuthenticationCode* extractor;
       MessageAuthenticationCode* prf;
 
       std::vector<EntropySource*> entropy_sources;
-      u32bit entropy;
+      bool seeded;
 
       SecureVector<byte> K, io_buffer;
       u32bit counter, source_index;
diff --git a/src/rng/randpool/randpool.cpp b/src/rng/randpool/randpool.cpp
index e35ee22ca..af36c335f 100644
--- a/src/rng/randpool/randpool.cpp
+++ b/src/rng/randpool/randpool.cpp
@@ -1,7 +1,7 @@
-/*************************************************
-* Randpool Source File                           *
-* (C) 1999-2008 Jack Lloyd                       *
-*************************************************/
+/*
+* Randpool Source File
+* (C) 1999-2009 Jack Lloyd
+*/
 
 #include <botan/randpool.h>
 #include <botan/loadstor.h>
@@ -14,9 +14,9 @@ namespace Botan {
 
 namespace {
 
-/*************************************************
-* PRF based on a MAC                             *
-*************************************************/
+/**
+* PRF based on a MAC
+*/
 enum RANDPOOL_PRF_TAG {
    CIPHER_KEY = 0,
    MAC_KEY    = 1,
@@ -25,18 +25,13 @@ enum RANDPOOL_PRF_TAG {
 
 }
 
-/*************************************************
-* Generate a buffer of random bytes              *
-*************************************************/
+/**
+* Generate a buffer of random bytes
+*/
 void Randpool::randomize(byte out[], u32bit length)
    {
    if(!is_seeded())
-      {
-      reseed();
-
-      if(!is_seeded())
-         throw PRNG_Unseeded(name());
-      }
+      throw PRNG_Unseeded(name());
 
    update_buffer();
    while(length)
@@ -49,15 +44,15 @@ void Randpool::randomize(byte out[], u32bit length)
       }
    }
 
-/*************************************************
-* Refill the output buffer                       *
-*************************************************/
+/**
+* Refill the output buffer
+*/
 void Randpool::update_buffer()
    {
    const u64bit timestamp = system_time();
 
-   for(u32bit j = 0; j != counter.size(); ++j)
-      if(++counter[j])
+   for(u32bit i = 0; i != counter.size(); ++i)
+      if(++counter[i])
          break;
    store_be(timestamp, counter + 4);
 
@@ -65,17 +60,17 @@ void Randpool::update_buffer()
    mac->update(counter, counter.size());
    SecureVector<byte> mac_val = mac->final();
 
-   for(u32bit j = 0; j != mac_val.size(); ++j)
-      buffer[j % buffer.size()] ^= mac_val[j];
+   for(u32bit i = 0; i != mac_val.size(); ++i)
+      buffer[i % buffer.size()] ^= mac_val[i];
    cipher->encrypt(buffer);
 
    if(counter[0] % ITERATIONS_BEFORE_RESEED == 0)
       mix_pool();
    }
 
-/*************************************************
-* Mix the entropy pool                           *
-*************************************************/
+/**
+* Mix the entropy pool
+*/
 void Randpool::mix_pool()
    {
    const u32bit BLOCK_SIZE = cipher->BLOCK_SIZE;
@@ -90,10 +85,10 @@ void Randpool::mix_pool()
 
    xor_buf(pool, buffer, BLOCK_SIZE);
    cipher->encrypt(pool);
-   for(u32bit j = 1; j != POOL_BLOCKS; ++j)
+   for(u32bit i = 1; i != POOL_BLOCKS; ++i)
       {
-      const byte* previous_block = pool + BLOCK_SIZE*(j-1);
-      byte* this_block = pool + BLOCK_SIZE*j;
+      const byte* previous_block = pool + BLOCK_SIZE*(i-1);
+      byte* this_block = pool + BLOCK_SIZE*i;
       xor_buf(this_block, previous_block, BLOCK_SIZE);
       cipher->encrypt(this_block);
       }
@@ -101,48 +96,19 @@ void Randpool::mix_pool()
    update_buffer();
    }
 
-/*************************************************
-* Reseed the internal state                      *
-*************************************************/
-void Randpool::reseed()
+/**
+* Reseed the internal state
+*/
+void Randpool::reseed(u32bit poll_bits)
    {
-   SecureVector<byte> buffer(128);
-
-   u32bit entropy_est = 0;
+   Entropy_Accumulator_BufferedComputation accum(*mac, poll_bits);
 
-   /*
-   When we reseed, assume we get 1 bit per byte sampled.
-
-   This class used to perform entropy estimation, but what we really
-   want to measure is the conditional entropy of the data with respect
-   to an unknown attacker with unknown capabilities.  For this reason
-   making any sort of sane estimate is impossible. See also
-      "Boaz Barak, Shai Halevi: A model and architecture for
-       pseudo-random generation with applications to /dev/random. ACM
-       Conference on Computer and Communications Security 2005."
-   */
-
-   // First do a fast poll of all sources (no matter what)
-   for(u32bit j = 0; j != entropy_sources.size(); ++j)
+   for(u32bit i = 0; i != entropy_sources.size(); ++i)
       {
-      u32bit got = entropy_sources[j]->fast_poll(buffer, buffer.size());
-
-      mac->update(buffer, got);
-      entropy_est += got;
-      buffer.clear();
-      }
+      entropy_sources[i]->poll(accum);
 
-   // Then do a slow poll, until we think we have got enough entropy
-   for(u32bit j = 0; j != entropy_sources.size(); ++j)
-      {
-      u32bit got = entropy_sources[j]->slow_poll(buffer, buffer.size());
-
-      mac->update(buffer, got);
-      entropy_est += got;
-
-      if(entropy_est > 512)
+      if(accum.polling_goal_achieved())
          break;
-      buffer.clear();
       }
 
    SecureVector<byte> mac_val = mac->final();
@@ -150,41 +116,34 @@ void Randpool::reseed()
    xor_buf(pool, mac_val, mac_val.size());
    mix_pool();
 
-   entropy = std::min<u32bit>(entropy + entropy_est, 8 * mac_val.size());
+   if(accum.bits_collected() >= poll_bits)
+      seeded = true;
    }
 
-/*************************************************
-* Add user-supplied entropy                      *
-*************************************************/
+/**
+* Add user-supplied entropy
+*/
 void Randpool::add_entropy(const byte input[], u32bit length)
    {
    SecureVector<byte> mac_val = mac->process(input, length);
    xor_buf(pool, mac_val, mac_val.size());
    mix_pool();
 
-   // Assume 1 bit conditional entropy per byte of input
-   entropy = std::min<u32bit>(entropy + length, 8 * mac_val.size());
+   if(length)
+      seeded = true;
    }
 
-/*************************************************
-* Add another entropy source to the list         *
-*************************************************/
+/**
+* Add another entropy source to the list
+*/
 void Randpool::add_entropy_source(EntropySource* src)
    {
    entropy_sources.push_back(src);
    }
 
-/*************************************************
-* Check if the the pool is seeded                *
-*************************************************/
-bool Randpool::is_seeded() const
-   {
-   return (entropy >= 7 * mac->OUTPUT_LENGTH);
-   }
-
-/*************************************************
-* Clear memory of sensitive data                 *
-*************************************************/
+/**
+* Clear memory of sensitive data
+*/
 void Randpool::clear() throw()
    {
    cipher->clear();
@@ -192,20 +151,20 @@ void Randpool::clear() throw()
    pool.clear();
    buffer.clear();
    counter.clear();
-   entropy = 0;
+   seeded = false;
    }
 
-/*************************************************
-* Return the name of this type                   *
-*************************************************/
+/**
+* Return the name of this type
+*/
 std::string Randpool::name() const
    {
    return "Randpool(" + cipher->name() + "," + mac->name() + ")";
    }
 
-/*************************************************
-* Randpool Constructor                           *
-*************************************************/
+/**
+* Randpool Constructor
+*/
 Randpool::Randpool(BlockCipher* cipher_in,
                    MessageAuthenticationCode* mac_in,
                    u32bit pool_blocks,
@@ -231,12 +190,12 @@ Randpool::Randpool(BlockCipher* cipher_in,
    buffer.create(BLOCK_SIZE);
    pool.create(POOL_BLOCKS * BLOCK_SIZE);
    counter.create(12);
-   entropy = 0;
+   seeded = false;
    }
 
-/*************************************************
-* Randpool Destructor                            *
-*************************************************/
+/**
+* Randpool Destructor
+*/
 Randpool::~Randpool()
    {
    delete cipher;
@@ -244,8 +203,6 @@ Randpool::~Randpool()
 
    std::for_each(entropy_sources.begin(), entropy_sources.end(),
                  del_fun<EntropySource>());
-
-   entropy = 0;
    }
 
 }
diff --git a/src/rng/randpool/randpool.h b/src/rng/randpool/randpool.h
index f6bae9d52..f44527609 100644
--- a/src/rng/randpool/randpool.h
+++ b/src/rng/randpool/randpool.h
@@ -1,7 +1,7 @@
-/*************************************************
-* Randpool Header File                           *
-* (C) 1999-2008 Jack Lloyd                       *
-*************************************************/
+/*
+* Randpool Header File
+* (C) 1999-2008 Jack Lloyd
+*/
 
 #ifndef BOTAN_RANDPOOL_H__
 #define BOTAN_RANDPOOL_H__
@@ -13,22 +13,22 @@
 
 namespace Botan {
 
-/*************************************************
-* Randpool                                       *
-*************************************************/
+/**
+* Randpool
+*/
 class BOTAN_DLL Randpool : public RandomNumberGenerator
    {
    public:
       void randomize(byte[], u32bit);
-      bool is_seeded() const;
+      bool is_seeded() const { return seeded; }
       void clear() throw();
       std::string name() const;
 
-      void reseed();
-      void add_entropy_source(EntropySource*);
-      void add_entropy(const byte[], u32bit);
+      void reseed(u32bit bits_to_collect);
+      void add_entropy_source(EntropySource* es);
+      void add_entropy(const byte input[], u32bit length);
 
-      Randpool(BlockCipher*, MessageAuthenticationCode*,
+      Randpool(BlockCipher* cipher, MessageAuthenticationCode* mac,
                u32bit pool_blocks = 32,
                u32bit iterations_before_reseed = 128);
 
@@ -43,7 +43,7 @@ class BOTAN_DLL Randpool : public RandomNumberGenerator
 
       std::vector<EntropySource*> entropy_sources;
       SecureVector<byte> pool, buffer, counter;
-      u32bit entropy;
+      bool seeded;
    };
 
 }
diff --git a/src/rng/rng.h b/src/rng/rng.h
index fb92bb3c5..7fc6ee439 100644
--- a/src/rng/rng.h
+++ b/src/rng/rng.h
@@ -1,7 +1,7 @@
-/*************************************************
-* RandomNumberGenerator Header File              *
-* (C) 1999-2008 Jack Lloyd                       *
-*************************************************/
+/*
+* RandomNumberGenerator Header File
+* (C) 1999-2009 Jack Lloyd
+*/
 
 #ifndef BOTAN_RANDOM_NUMBER_GENERATOR_H__
 #define BOTAN_RANDOM_NUMBER_GENERATOR_H__
@@ -54,8 +54,10 @@ class BOTAN_DLL RandomNumberGenerator
 
       /**
       * Seed this RNG using the entropy sources it contains.
+      * @param bits_to_collect is the number of bits of entropy to
+               attempt to gather from the entropy sources
       */
-      virtual void reseed() {}
+      virtual void reseed(u32bit bits_to_collect) = 0;
 
       /**
       * Add this entropy source to the RNG object
@@ -88,6 +90,7 @@ class BOTAN_DLL Null_RNG : public RandomNumberGenerator
       void clear() throw() {}
       std::string name() const { return "Null_RNG"; }
 
+      void reseed(u32bit) {}
       bool is_seeded() const { return false; }
       void add_entropy(const byte[], u32bit) {}
       void add_entropy_source(EntropySource* es) { delete es; }
diff --git a/src/rng/x931_rng/x931_rng.cpp b/src/rng/x931_rng/x931_rng.cpp
index 619c37e57..e77f04ae4 100644
--- a/src/rng/x931_rng/x931_rng.cpp
+++ b/src/rng/x931_rng/x931_rng.cpp
@@ -1,7 +1,7 @@
-/*************************************************
-* ANSI X9.31 RNG Source File                     *
-* (C) 1999-2008 Jack Lloyd                       *
-*************************************************/
+/*
+* ANSI X9.31 RNG Source File
+* (C) 1999-2009 Jack Lloyd
+*/
 
 #include <botan/x931_rng.h>
 #include <botan/xor_buf.h>
@@ -9,13 +9,13 @@
 
 namespace Botan {
 
-/*************************************************
-* Generate a buffer of random bytes              *
-*************************************************/
+/**
+* Generate a buffer of random bytes
+*/
 void ANSI_X931_RNG::randomize(byte out[], u32bit length)
    {
    if(!is_seeded())
-      reseed();
+      throw PRNG_Unseeded(name());
 
    while(length)
       {
@@ -31,9 +31,9 @@ void ANSI_X931_RNG::randomize(byte out[], u32bit length)
       }
    }
 
-/*************************************************
-* Refill the internal state                      *
-*************************************************/
+/**
+* Refill the internal state
+*/
 void ANSI_X931_RNG::update_buffer()
    {
    SecureVector<byte> DT(cipher->BLOCK_SIZE);
@@ -50,13 +50,11 @@ void ANSI_X931_RNG::update_buffer()
    position = 0;
    }
 
-/*************************************************
-* Reseed the internal state                      *
-*************************************************/
-void ANSI_X931_RNG::reseed()
+/**
+* Reset V and the cipher key with new values
+*/
+void ANSI_X931_RNG::rekey()
    {
-   prng->reseed();
-
    if(prng->is_seeded())
       {
       SecureVector<byte> key(cipher->MAXIMUM_KEYLENGTH);
@@ -71,33 +69,43 @@ void ANSI_X931_RNG::reseed()
       }
    }
 
-/*************************************************
-* Add a entropy source to the underlying PRNG    *
-*************************************************/
+/**
+* Reseed the internal state
+*/
+void ANSI_X931_RNG::reseed(u32bit poll_bits)
+   {
+   prng->reseed(poll_bits);
+   rekey();
+   }
+
+/**
+* Add a entropy source to the underlying PRNG
+*/
 void ANSI_X931_RNG::add_entropy_source(EntropySource* src)
    {
    prng->add_entropy_source(src);
    }
 
-/*************************************************
-* Add some entropy to the underlying PRNG        *
-*************************************************/
+/**
+* Add some entropy to the underlying PRNG
+*/
 void ANSI_X931_RNG::add_entropy(const byte input[], u32bit length)
    {
    prng->add_entropy(input, length);
+   rekey();
    }
 
-/*************************************************
-* Check if the the PRNG is seeded                *
-*************************************************/
+/**
+* Check if the the PRNG is seeded
+*/
 bool ANSI_X931_RNG::is_seeded() const
    {
    return V.has_items();
    }
 
-/*************************************************
-* Clear memory of sensitive data                 *
-*************************************************/
+/**
+* Clear memory of sensitive data
+*/
 void ANSI_X931_RNG::clear() throw()
    {
    cipher->clear();
@@ -108,17 +116,17 @@ void ANSI_X931_RNG::clear() throw()
    position = 0;
    }
 
-/*************************************************
-* Return the name of this type                   *
-*************************************************/
+/**
+* Return the name of this type
+*/
 std::string ANSI_X931_RNG::name() const
    {
    return "X9.31(" + cipher->name() + ")";
    }
 
-/*************************************************
-* ANSI X931 RNG Constructor                      *
-*************************************************/
+/**
+* ANSI X931 RNG Constructor
+*/
 ANSI_X931_RNG::ANSI_X931_RNG(BlockCipher* cipher_in,
                              RandomNumberGenerator* prng_in)
    {
@@ -132,9 +140,9 @@ ANSI_X931_RNG::ANSI_X931_RNG(BlockCipher* cipher_in,
    position = 0;
    }
 
-/*************************************************
-* ANSI X931 RNG Destructor                       *
-*************************************************/
+/**
+* ANSI X931 RNG Destructor
+*/
 ANSI_X931_RNG::~ANSI_X931_RNG()
    {
    delete cipher;
diff --git a/src/rng/x931_rng/x931_rng.h b/src/rng/x931_rng/x931_rng.h
index e1d090c3c..b1cef8df3 100644
--- a/src/rng/x931_rng/x931_rng.h
+++ b/src/rng/x931_rng/x931_rng.h
@@ -1,7 +1,7 @@
-/*************************************************
-* ANSI X9.31 RNG Header File                     *
-* (C) 1999-2008 Jack Lloyd                       *
-*************************************************/
+/*
+* ANSI X9.31 RNG Header File
+* (C) 1999-2009 Jack Lloyd
+*/
 
 #ifndef BOTAN_ANSI_X931_RNG_H__
 #define BOTAN_ANSI_X931_RNG_H__
@@ -11,9 +11,9 @@
 
 namespace Botan {
 
-/*************************************************
-* ANSI X9.31 RNG                                 *
-*************************************************/
+/**
+* ANSI X9.31 RNG
+*/
 class BOTAN_DLL ANSI_X931_RNG : public RandomNumberGenerator
    {
    public:
@@ -22,13 +22,14 @@ class BOTAN_DLL ANSI_X931_RNG : public RandomNumberGenerator
       void clear() throw();
       std::string name() const;
 
-      void reseed();
+      void reseed(u32bit poll_bits);
       void add_entropy_source(EntropySource*);
       void add_entropy(const byte[], u32bit);
 
       ANSI_X931_RNG(BlockCipher*, RandomNumberGenerator*);
       ~ANSI_X931_RNG();
    private:
+      void rekey();
       void update_buffer();
 
       BlockCipher* cipher;
diff --git a/src/timer/timer.cpp b/src/timer/timer.cpp
index 8758aad21..a801761cf 100644
--- a/src/timer/timer.cpp
+++ b/src/timer/timer.cpp
@@ -1,6 +1,6 @@
 /**
 * Timestamp Functions Source File
-* (C) 1999-2008 Jack Lloyd
+* (C) 1999-2009 Jack Lloyd
 */
 
 #include <botan/timer.h>
@@ -21,19 +21,10 @@ u64bit system_time()
 /**
 * Read the clock and return the output
 */
-u32bit Timer::fast_poll(byte out[], u32bit length)
+void Timer::poll(Entropy_Accumulator& accum)
    {
    const u64bit clock_value = this->clock();
-
-   for(u32bit j = 0; j != sizeof(clock_value); ++j)
-      out[j % length] ^= get_byte(j, clock_value);
-
-   return (length < 8) ? length : 8;
-   }
-
-u32bit Timer::slow_poll(byte out[], u32bit length)
-   {
-   return fast_poll(out, length);
+   accum.add(clock_value, 0);
    }
 
 /**
@@ -56,5 +47,4 @@ u64bit ANSI_Clock_Timer::clock() const
    return combine_timers(std::time(0), std::clock(), CLOCKS_PER_SEC);
    }
 
-
 }
diff --git a/src/timer/timer.h b/src/timer/timer.h
index af2c58dcb..0e0dcc62e 100644
--- a/src/timer/timer.h
+++ b/src/timer/timer.h
@@ -1,6 +1,6 @@
 /**
 * Timestamp Functions Header File
-* (C) 1999-2008 Jack Lloyd
+* (C) 1999-2009 Jack Lloyd
 */
 
 #ifndef BOTAN_TIMERS_H__
@@ -21,8 +21,7 @@ class BOTAN_DLL Timer : public EntropySource
       */
       virtual u64bit clock() const = 0;
 
-      u32bit slow_poll(byte[], u32bit);
-      u32bit fast_poll(byte[], u32bit);
+      void poll(Entropy_Accumulator& accum);
 
       virtual ~Timer() {}
    protected:
diff --git a/src/utils/info.txt b/src/utils/info.txt
index 915ce50b0..ffc19c852 100644
--- a/src/utils/info.txt
+++ b/src/utils/info.txt
@@ -42,6 +42,5 @@ util.cpp
 util.h
 version.cpp
 version.h
-xor_buf.cpp
 xor_buf.h
 </add>
diff --git a/src/utils/xor_buf.cpp b/src/utils/xor_buf.cpp
deleted file mode 100644
index 779be81c3..000000000
--- a/src/utils/xor_buf.cpp
+++ /dev/null
@@ -1,44 +0,0 @@
-/**
-* XOR operations
-* (C) 1999-2008 Jack Lloyd
-*/
-
-#include <botan/xor_buf.h>
-#include <botan/loadstor.h>
-
-namespace Botan {
-
-/**
-* Xor values into buffer
-*/
-u32bit xor_into_buf(byte buf[], u32bit buf_i, u32bit length,
-                    const void* in_void, u32bit in_len)
-   {
-   const byte* in = static_cast<const byte*>(in_void);
-
-   byte last = 0;
-   byte count = 0;
-
-   for(u32bit i = 0; i != in_len; ++i)
-      {
-      if(in[i] != last)
-         {
-         buf[buf_i] ^= last;
-         buf_i = (buf_i + 1) % length;
-
-         buf[buf_i] ^= count;
-         buf_i = (buf_i + 1) % length;
-
-         last = in[i];
-         count = 1;
-         }
-      else
-         ++count;
-      }
-
-   // final values of last, count are thrown away
-
-   return buf_i;
-   }
-
-}
diff --git a/src/utils/xor_buf.h b/src/utils/xor_buf.h
index 076877e02..2bf6ced59 100644
--- a/src/utils/xor_buf.h
+++ b/src/utils/xor_buf.h
@@ -67,24 +67,6 @@ inline void xor_buf(byte out[],
       out[j] = in[j] ^ in2[j];
    }
 
-/**
-* XOR values into buffer. Uses RLE compression
-* Intended for use in entropy sources to gather collected
-* data into a buffer to pass to an RNG.
-*/
-u32bit xor_into_buf(byte buf[], u32bit buf_i, u32bit length,
-                    const void* in_void, u32bit in_len);
-
-/**
-* XOR integer value (or something else, I guess) into buffer
-*/
-template<typename T>
-u32bit xor_into_buf(byte buf[], u32bit buf_i,
-                    u32bit length, const T& in)
-   {
-   return xor_into_buf(buf, buf_i, length, &in, sizeof(in));
-   }
-
 }
 
 #endif