add entry to ChangeLog
diff --git a/ChangeLog b/ChangeLog
index 9b1230e..f115015 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -24,6 +24,13 @@
    * Remove the mbedtls namespacing from the header file, to fix a "file not found"
      build error. Fixed by Haijun Gu #2319.
    * Fix returning the value 1 when mbedtls_ecdsa_genkey failed.
+   * Server's RSA certificate in certs.c was SHA-1 signed. In the default
+     mbedTLS configuration only SHA-2 signed certificates are accepted.
+     This certificate is used in the demo server programs, which lead the
+     client programs to fail at the peer's certificate verification
+     due to an unacceptable hash signature. The certificate has been
+     updated to one that is SHA-256 signed. Fix contributed by
+     Illya Gerasymchuk.
 
 Changes
    * Include configuration file in all header files that use configuration,