crypto: require nettle >= 2.7.1 for building QEMU

nettle 2.7.1 was released in 2013 and all the distros that are build
target platforms for QEMU [1] include it:

  RHEL-7: 2.7.1
  Debian (Stretch): 3.3
  Debian (Jessie): 2.7.1
  OpenBSD (ports): 3.4
  FreeBSD (ports): 3.4
  OpenSUSE Leap 15: 3.4
  Ubuntu (Xenial): 3.2
  macOS (Homebrew): 3.4

Based on this, it is reasonable to require nettle >= 2.7.1 in QEMU
which allows for some conditional version checks in the code to be
removed.

[1] https://qemu.weilnetz.de/doc/qemu-doc.html#Supported-build-platforms

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

4 files changed, 6 insertions, 22 deletions

diff --git a/configure b/configure
index f943d6618a..5a508206e1 100755
--- a/configure
+++ b/configure
@@ -458,7 +458,6 @@ gtk_gl="no"
 tls_priority="NORMAL"
 gnutls=""
 nettle=""
-nettle_kdf="no"
 gcrypt=""
 gcrypt_hmac="no"
 vte=""
@@ -2730,7 +2729,7 @@ has_libgcrypt() {
 
 
 if test "$nettle" != "no"; then
-    if $pkg_config --exists "nettle"; then
+    if $pkg_config --exists "nettle >= 2.7.1"; then
         nettle_cflags=$($pkg_config --cflags nettle)
         nettle_libs=$($pkg_config --libs nettle)
         nettle_version=$($pkg_config --modversion nettle)
@@ -2739,23 +2738,12 @@ if test "$nettle" != "no"; then
         QEMU_CFLAGS="$QEMU_CFLAGS $nettle_cflags"
         nettle="yes"
 
-        cat > $TMPC << EOF
-#include <stddef.h>
-#include <nettle/pbkdf2.h>
-int main(void) {
-     pbkdf2_hmac_sha256(8, NULL, 1000, 8, NULL, 8, NULL);
-     return 0;
-}
-EOF
         if test -z "$gcrypt"; then
            gcrypt="no"
         fi
-        if compile_prog "$nettle_cflags" "$nettle_libs" ; then
-            nettle_kdf=yes
-        fi
     else
         if test "$nettle" = "yes"; then
-            feature_not_found "nettle" "Install nettle devel"
+            feature_not_found "nettle" "Install nettle devel >= 2.7.1"
         else
             nettle="no"
         fi
@@ -5906,7 +5894,6 @@ echo "TLS priority      $tls_priority"
 echo "GNUTLS support    $gnutls"
 echo "libgcrypt         $gcrypt"
 echo "nettle            $nettle $(echo_version $nettle $nettle_version)"
-echo "nettle kdf        $nettle_kdf"
 echo "libtasn1          $tasn1"
 echo "curses support    $curses"
 echo "virgl support     $virglrenderer $(echo_version $virglrenderer $virgl_version)"
@@ -6351,9 +6338,6 @@ fi
 if test "$nettle" = "yes" ; then
   echo "CONFIG_NETTLE=y" >> $config_host_mak
   echo "CONFIG_NETTLE_VERSION_MAJOR=${nettle_version%%.*}" >> $config_host_mak
-  if test "$nettle_kdf" = "yes" ; then
-    echo "CONFIG_NETTLE_KDF=y" >> $config_host_mak
-  fi
 fi
 if test "$tasn1" = "yes" ; then
   echo "CONFIG_TASN1=y" >> $config_host_mak
diff --git a/crypto/Makefile.objs b/crypto/Makefile.objs
index 6a908f51f5..256c9aca1f 100644
--- a/crypto/Makefile.objs
+++ b/crypto/Makefile.objs
@@ -23,8 +23,8 @@ crypto-obj-$(CONFIG_GCRYPT) += random-gcrypt.o
 crypto-obj-$(if $(CONFIG_GCRYPT),n,$(CONFIG_GNUTLS)) += random-gnutls.o
 crypto-obj-$(if $(CONFIG_GCRYPT),n,$(if $(CONFIG_GNUTLS),n,y)) += random-platform.o
 crypto-obj-y += pbkdf.o
-crypto-obj-$(CONFIG_NETTLE_KDF) += pbkdf-nettle.o
-crypto-obj-$(if $(CONFIG_NETTLE_KDF),n,$(CONFIG_GCRYPT)) += pbkdf-gcrypt.o
+crypto-obj-$(CONFIG_NETTLE) += pbkdf-nettle.o
+crypto-obj-$(if $(CONFIG_NETTLE),n,$(CONFIG_GCRYPT)) += pbkdf-gcrypt.o
 crypto-obj-y += ivgen.o
 crypto-obj-y += ivgen-essiv.o
 crypto-obj-y += ivgen-plain.o
diff --git a/tests/Makefile.include b/tests/Makefile.include
index 0c8113ffa6..f77a495109 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -115,7 +115,7 @@ check-unit-$(CONFIG_GNUTLS) += tests/test-io-channel-tls$(EXESUF)
 check-unit-y += tests/test-io-channel-command$(EXESUF)
 check-unit-y += tests/test-io-channel-buffer$(EXESUF)
 check-unit-y += tests/test-base64$(EXESUF)
-check-unit-$(if $(CONFIG_NETTLE_KDF),y,$(CONFIG_GCRYPT)) += tests/test-crypto-pbkdf$(EXESUF)
+check-unit-$(if $(CONFIG_NETTLE),y,$(CONFIG_GCRYPT)) += tests/test-crypto-pbkdf$(EXESUF)
 check-unit-y += tests/test-crypto-ivgen$(EXESUF)
 check-unit-y += tests/test-crypto-afsplit$(EXESUF)
 check-unit-y += tests/test-crypto-xts$(EXESUF)
diff --git a/tests/test-crypto-block.c b/tests/test-crypto-block.c
index bd512cc79a..fae4ffc453 100644
--- a/tests/test-crypto-block.c
+++ b/tests/test-crypto-block.c
@@ -29,7 +29,7 @@
 #endif
 
 #if (defined(_WIN32) || defined RUSAGE_THREAD) && \
-    (defined(CONFIG_NETTLE_KDF) || defined(CONFIG_GCRYPT))
+    (defined(CONFIG_NETTLE) || defined(CONFIG_GCRYPT))
 #define TEST_LUKS
 #else
 #undef TEST_LUKS