Merge pull request #2418 from dgarske/sha3_keccak256

Added support for older KECCAK256

configure.ac

@@ -188,6 +188,7 @@ then
     enable_scrypt=yes
     enable_indef=yes
     enable_enckeys=yes
+    enable_hashflags=yes
 
     # Enable AES Decrypt, AES ECB, Alt Names, DER Load, Keep Certs, CRL IO with Timeout
     AM_CFLAGS="$AM_CFLAGS -DHAVE_AES_DECRYPT -DHAVE_AES_ECB -DWOLFSSL_ALT_NAMES -DWOLFSSL_DER_LOAD -DKEEP_OUR_CERT -DKEEP_PEER_CERT -DHAVE_CRL_IO -DHAVE_IO_TIMEOUT"
@@ -4367,6 +4368,20 @@ then
 fi
 
 
+# Enable hash flags support
+# Hash flags are useful for runtime options such as SHA3 KECCAK256 selection
+AC_ARG_ENABLE([hashflags],
+    [AS_HELP_STRING([--enable-hashflags],[Enable support for hash flags (default: disabled)])],
+    [ ENABLED_HASHFLAGS=$enableval ],
+    [ ENABLED_HASHFLAGS=no ]
+    )
+
+if test "x$ENABLED_HASHFLAGS" != "xno"
+then
+    AM_CFLAGS="$AM_CFLAGS -DWOLFSSL_HASH_FLAGS"
+fi
+
+
 # User Settings
 AC_ARG_ENABLE([usersettings],
     [AS_HELP_STRING([--enable-usersettings],[Use your own user_settings.h and do not add Makefile CFLAGS (default: disabled)])],
@@ -4763,6 +4778,7 @@ AM_CONDITIONAL([BUILD_TRUST_PEER_CERT],[test "x$have_tp" = "xyes"])
 AM_CONDITIONAL([BUILD_PKI],[test "x$ENABLED_PKI" = "xyes"])
 AM_CONDITIONAL([BUILD_DES3],[test "x$ENABLED_DES3" = "xyes"])
 AM_CONDITIONAL([BUILD_PKCS7],[test "x$ENABLED_PKCS7" = "xyes"])
+AM_CONDITIONAL([BUILD_HASHFLAGS],[test "x$ENABLED_HASHFLAGS" = "xyes"])
 
 
 CREATE_HEX_VERSION