Make HKDF support experimental.

Change-Id: I2cd2d4847b295608761beea03e861d9bc0c9c779
Signed-off-by: Steve Linsell <[email protected]>

.tools/configure.ac

@@ -58,8 +58,8 @@ AC_ARG_ENABLE(qat_prf,
 AC_SUBST(enable_qat_prf)
 
 AC_ARG_ENABLE(qat_hkdf,
-              AS_HELP_STRING([--disable-qat_hkdf],
-                             [Disable accelerated HKDF offload]))
+              AS_HELP_STRING([--enable-qat_hkdf],
+                             [Enable accelerated HKDF offload]))
 AC_SUBST(enable_qat_hkdf)
 
 AC_ARG_ENABLE(qat_small_pkt_offload,
@@ -289,7 +289,7 @@ else
   AC_MSG_NOTICE([Not Offloading PRF to Hardware])
 fi
 
-if test "x$enable_qat_hkdf" != "xno"
+if test "x$enable_qat_hkdf" = "xyes"
 then
   enable_qat_hkdf="-DOPENSSL_ENABLE_QAT_HKDF"
   AC_MSG_NOTICE([Offloading HKDF to Hardware])

README.md

@@ -1426,11 +1426,11 @@ a slow down in performance until the acceleration device comes back online.
 
 The HKDF support in the Intel® QAT OpenSSL\* Engine is available only from
 Version 4.8 of Intel® QuickAssist Technology Driver for Linux HW Version 1.7.
-If any other lower version of driver is used then the Intel® QAT OpenSSL\* Engine
-needs to be configured to disable HKDF offload using the below flag.
+By default this support is disabled as it is added as an experimental feature.
+It can be enabled using the below flag in the configure command.
 
 ```bash
---disable-qat_hkdf
+--enable-qat_hkdf
 ```
 
 ## Legal