Update openssl configure tests.

ChangeLog

+2017-08-26  Niels Möller  <nisse@lysator.liu.se>
+
+	* configure.ac: Update openssl-related tests. Checks for
+	cipher-specific headers are replaced by a check for openssl/evp.h,
+	and the check for the BF_ecb_encrypt function is replaced by a
+	check for EVP_CIPHER_CTX_new.
+
+2017-08-03  Daniel P. Berrange  <berrange@redhat.com>
+
+	* examples/nettle-openssl.c: Rewritten to use openssl's EVP APIs.
+	The older cipher-specific functions always use openssl's generic
+	software implementation, while the EVP functions enables
+	platform-specific code, e.g., using the x86 AES-NI instructions.
+	(nettle_openssl_init): New function.
+
 2017-07-18  Niels Möller  <nisse@lysator.liu.se>
 
 	* ecc-add-eh.c (ecc_add_eh): Fix in-place operation by reordering

configure.ac

@@ -185,7 +185,7 @@ AC_HEADER_TIME
 AC_CHECK_SIZEOF(long)
 AC_CHECK_SIZEOF(size_t)
 
-AC_CHECK_HEADERS([openssl/blowfish.h openssl/des.h openssl/cast.h openssl/aes.h openssl/ecdsa.h],,
+AC_CHECK_HEADERS([openssl/evp.h openssl/ecdsa.h],,
 [enable_openssl=no
  break])
 
@@ -876,7 +876,7 @@ OPENSSL_LIBFLAGS=''
 
 # Check for openssl's libcrypto (used only for benchmarking)
 if test x$enable_openssl = xyes ; then
-  AC_CHECK_LIB(crypto, BF_ecb_encrypt,
+  AC_CHECK_LIB(crypto, EVP_CIPHER_CTX_new,
     [OPENSSL_LIBFLAGS='-lcrypto'],
     [enable_openssl=no])
 fi