hs_pow: Add CompiledProofOfWorkHash torrc option

This exposes the new fallback behavior in hashx via a new AUTOBOOL
configuration option, available to both clients and services. The
default should be fine for nearly everyone, but it might be necessary
to enable or disable the compiler manually for diagnostic purposes.

Signed-off-by: Micah Elizabeth Scott <beth@torproject.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/doc/man/tor.1.txt b/doc/man/tor.1.txt
index 19fdf90c90..1589809b1a 100644
--- a/doc/man/tor.1.txt
+++ b/doc/man/tor.1.txt
@@ -3119,6 +3119,21 @@ The following options are per onion service:
     The maximum burst size for rendezvous requests handled from the
     priority queue at once. (Default: 2500)
 
+These options are applicable to both onion services and their clients:
+
+[[CompiledProofOfWorkHash]] **CompiledProofOfWorkHash** **0**|**1**|**auto**::
+    When proof-of-work DoS mitigation is active, both the services themselves
+    and the clients which connect will use a dynamically generated hash
+    function as part of the puzzle computation.
+     +
+    If this option is set to 1, puzzles will only be solved and verified using
+    the compiled implementation (about 20x faster) and we choose to fail rather
+    than using a slower fallback. If it's 0, the compiler will never be used.
+    By default, the compiler is always tried if possible but the interpreter is
+    available as a fallback. (Default: auto)
+
+See also <<opt-list-modules,`--list-modules`>>, these proof of work options
+have no effect unless the "`pow`" module is enabled at compile time.
 
 == DIRECTORY AUTHORITY SERVER OPTIONS