patch: initialize randpool with zeroes

Folks:

Here is a patch to initialize the randpool with zeroes.  I know  
opinions might differ about the value of this.  If Wei Dai wants, I  
could make a variant that is controlled by a #define or something.

Regards,

Zooko

Fri May 22 21:04:25 MDT 2009  zooko@...
   * initialize the randpool with zeroes instead of using whatever  
bits were there
   This makes valgrind stop complaining about using uninitialized  
memory.  There are other ways to make valgrind stop complaining, such  
as by explicitly telling it "See these here bytes?  Pretend from now  
on that they are initialized.", but I don't like using uninitialized  
memory for my randpool anyway.  If my randpool is broken, I would  
like for it to start giving the exact same output time after time (or  
a short cycle, or a selection from a small set, or whatever), so that  
the users and developers can more quickly detect the problem, rather  
than rely for my security on the values in the uninitialized memory,  
which might not be all that unpredictable.
diff -rN -u old-release-5.6.0-plus-zookopatches/c5/randpool.cpp new-
release-5.6.0-plus-zookopatches/c5/randpool.cpp
--- old-release-5.6.0-plus-zookopatches/c5/randpool.cpp 2009-05-23  
18:41:39.000000000 -0600
+++ new-release-5.6.0-plus-zookopatches/c5/randpool.cpp 2009-05-23  
18:41:41.000000000 -0600
@@ -19,6 +19,8 @@
  RandomPool::RandomPool()
  : m_pCipher(new AES::Encryption), m_keySet(false)
  {
+ memset(m_key, 0, 32);
+ memset(m_seed, 0, 16);
  }

  void RandomPool::IncorporateEntropy(const byte *input, size_t length)


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Fri May 22 21:04:25 MDT 2009  zooko@...
  * initialize the randpool with zeroes instead of using whatever bits were there
  This makes valgrind stop complaining about using uninitialized memory.  There are other ways to make valgrind stop complaining, such as by explicitly telling it "See these here bytes?  Pretend from now on that they are initialized.", but I don't like using uninitialized memory for my randpool anyway.  If my randpool is broken, I would like for it to start giving the exact same output time after time (or a short cycle, or a selection from a small set, or whatever), so that the users and developers can more quickly detect the problem, rather than rely for my security on the values in the uninitialized memory, which might not be all that unpredictable.
diff -rN -u old-release-5.6.0-plus-zookopatches/c5/randpool.cpp new-release-5.6.0-plus-zookopatches/c5/randpool.cpp
--- old-release-5.6.0-plus-zookopatches/c5/randpool.cpp 2009-05-23 18:41:39.000000000 -0600
+++ new-release-5.6.0-plus-zookopatches/c5/randpool.cpp 2009-05-23 18:41:41.000000000 -0600
@@ -19,6 +19,8 @@
 RandomPool::RandomPool()
  : m_pCipher(new AES::Encryption), m_keySet(false)
 {
+ memset(m_key, 0, 32);
+ memset(m_seed, 0, 16);
 }
 
 void RandomPool::IncorporateEntropy(const byte *input, size_t length)