Revert "fix nettle"

This reverts commit d31634c358.

Laurent Thomas had a problem on one machine with the build_oai
way of checking for nettle.

The problem with the alternative solution of including nettle/bignum.h
is that it is very unclear.

The problem with nettle is that the file nettle/config.h does not
exist for version 2. It was introduced in version 3.

We want to support both versions, but there is an API incompatibility.
So we need an #if #else mechanism.

The file nettle/bignum.h is present in both versions 2 and 3 and it
includes nettle/version.h in the version 3.

So by including this file, we can check for the existence of
NETTLE_VERSION_MAJOR (that comes from nettle/config.h) in the
code.

But as you can see, the reasoning is way too complex.

So it's better to keep the check in cmake_targets/CMakeLists.txt.

As long as we support version 2 this will be the way to go.

It is possible to force a given version in specific non-generic
customized environments.

cmake_targets/CMakeLists.txt

@@ -1664,6 +1664,18 @@ endif()
 
 message ("NETTLE VERSION_INSTALLED  = ${NETTLE_VERSION}")
 
+string(REGEX REPLACE "([0-9]+).*" "\\1" NETTLE_VERSION_MAJOR ${NETTLE_VERSION})
+string(REGEX REPLACE "[0-9]+\\.([0-9]+).*" "\\1" NETTLE_VERSION_MINOR ${NETTLE_VERSION})
+message ("NETTLE_VERSION_MAJOR = ${NETTLE_VERSION_MAJOR}")
+message ("NETTLE_VERSION_MINOR = ${NETTLE_VERSION_MINOR}")
+
+if ("${NETTLE_VERSION_MAJOR}" STREQUAL "" OR "${NETTLE_VERSION_MINOR}" STREQUAL "")
+  message( FATAL_ERROR "The nettle version not detected properly. Try to run build_oai -I again" )
+endif()
+
+add_definitions("-DNETTLE_VERSION_MAJOR=${NETTLE_VERSION_MAJOR}")
+add_definitions("-DNETTLE_VERSION_MINOR=${NETTLE_VERSION_MINOR}")
+
 pkg_search_module(XPM xpm)
 if(NOT ${XPM_FOUND})
   message("PACKAGE xpm not found: some targets will fail")

openair2/UTIL/OSA/osa_stream_eea.c

@@ -27,7 +27,6 @@
 #include <nettle/nettle-meta.h>
 #include <nettle/aes.h>
 #include <nettle/ctr.h>
-#include <nettle/bignum.h>
 
 #include "UTIL/LOG/log.h"
 
@@ -192,7 +191,7 @@ int stream_encrypt_eea2(stream_cipher_t *stream_cipher, uint8_t **out)
   }
 #endif
 
-#if !defined(NETTLE_VERSION_MAJOR) || NETTLE_VERSION_MAJOR < 3
+#if NETTLE_VERSION_MAJOR < 3
   nettle_aes128.set_encrypt_key(ctx, stream_cipher->key_length,
                                 stream_cipher->key);
 #else

openair3/SECU/nas_stream_eea2.c

@@ -27,7 +27,6 @@
 #include <nettle/nettle-meta.h>
 #include <nettle/aes.h>
 #include <nettle/ctr.h>
-#include <nettle/bignum.h>
 
 #include "assertions.h"
 #include "conversions.h"
@@ -79,7 +78,7 @@ int nas_stream_encrypt_eea2(nas_stream_cipher_t *stream_cipher, uint8_t *out)
   }
 #endif
 
-#if !defined(NETTLE_VERSION_MAJOR) || NETTLE_VERSION_MAJOR < 3
+#if NETTLE_VERSION_MAJOR < 3
   nettle_aes128.set_encrypt_key(ctx, stream_cipher->key_length,
                                 stream_cipher->key);
 #else

openair3/TEST/test_aes128_ctr_decrypt.c

@@ -31,7 +31,6 @@
 #include <nettle/nettle-meta.h>
 #include <nettle/aes.h>
 #include <nettle/ctr.h>
-#include <nettle/bignum.h>
 
 static
 void test_uncipher_ctr(const struct nettle_cipher *cipher, const uint8_t *key,
@@ -42,7 +41,7 @@ void test_uncipher_ctr(const struct nettle_cipher *cipher, const uint8_t *key,
   uint8_t *data = malloc(length);
   uint8_t *ctr = malloc(cipher->block_size);
 
-#if !defined(NETTLE_VERSION_MAJOR) || NETTLE_VERSION_MAJOR < 3
+#if NETTLE_VERSION_MAJOR < 3
   cipher->set_encrypt_key(ctx, key_length,  key);
 #else
   cipher->set_encrypt_key(ctx,  key);