Disable TLS signature and finished message checks in fuzzer mode

Also use a const time comparison for the finished message, though
I don't see any real way of exploiting that timing channel.

1 files changed, 8 insertions, 1 deletions

diff --git a/src/lib/tls/msg_cert_verify.cpp b/src/lib/tls/msg_cert_verify.cpp
index ac8fa97fd..2f8e8230e 100644
--- a/src/lib/tls/msg_cert_verify.cpp
+++ b/src/lib/tls/msg_cert_verify.cpp
@@ -90,7 +90,14 @@ bool Certificate_Verify::verify(const X509_Certificate& cert,
 
    PK_Verifier verifier(*key, format.first, format.second);
 
-   return verifier.verify_message(state.hash().get_contents(), m_signature);
+   const bool signature_valid =
+      verifier.verify_message(state.hash().get_contents(), m_signature);
+
+#if defined(BOTAN_UNSAFE_FUZZER_MODE)
+   return true;
+#else
+   return signature_valid;
+#endif
    }
 
 }