Previously, AutoRNG was just a reference to the global rng, which can

cause a huge amount of lock contention in heavily multithreaded
code. Now each AutoRNG is its own uniquely seeded HMAC_RNG. The set of
entropy sources is shared rather than being per-RNG (so there is only
one open fd to /dev/random, etc). So reseeding is still a global lock,
but sharing the resources (open file descriptors, etc) across RNGs
seems worth the contention.

Remove Randpool, which was only used if HMAC_RNG was disabled at build.

1 files changed, 6 insertions, 1 deletions

diff --git a/doc/relnotes/1_11_5.rst b/doc/relnotes/1_11_5.rst
index e4528a581..e3ee27a5e 100644
--- a/doc/relnotes/1_11_5.rst
+++ b/doc/relnotes/1_11_5.rst
@@ -18,6 +18,11 @@ Version 1.11.5, Not Yet Released
   urandom always occurs, along with however much (if any) output is available
   from blocking sources.
 
+* Previously AutoSeeded_RNG referenced a globally shared PRNG instance.
+  Now each instance has distinct state.
+
+* The Randpool RNG implementation was removed.
+
 * All existing cipher mode implementations (such as CBC and XTS) have been
   converted from filters to using the interface previously provided by
   :ref:`AEAD modes <aead_modes>` which allows for in-place message
@@ -37,7 +42,7 @@ Version 1.11.5, Not Yet Released
 
 * TLS channels now support sending a ``std::vector``
 
-* Add a generic 64-bit multiply instruction for producing a 128 bit result in mul128.h
+* Add a generic 64x64->128 bit multiply instruction operation in mul128.h
 
 * Avoid potentially undefined operations in the bit rotation operations. Not
   known to have caused problems under existing compilers but might break in the