Document how to update the corpus.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Andy Polyakov <appro@openssl.org>
GH: #2683

diff --git a/fuzz/README.md b/fuzz/README.md
index b4a40df917bfc6b4d2eb9186c254b8eb4ab4ef5d..3800ef166c76269dff1a411ae74f21f1ab9955d5 100644 (file)
--- a/fuzz/README.md
+++ b/fuzz/README.md
@@ -117,3 +117,15 @@ Since the corpus depends on the default behaviour of the client and the server,
 changes in what they send by default will have an impact on the coverage. The
 corpus will need to be updated in that case.
 
+Updating the corpus
+===================
+
+The client and server corpus is generated with multiple config options:
+- The options as documented above
+- Without enable-ec_nistp_64_gcc_128 and without --debug
+- With no-asm
+- Using 32 bit
+- A default config, plus options needed to generate the fuzzer.
+
+The libfuzzer merge option is used to add the additional coverage
+from each config to the minimal set.