Re: [Qemu-devel] [PATCH] crypto: do an explicit check for nettle pbkdf functions

["Daniel P. Berrange" <berrange@redhat.com>]

On Thu, Mar 31, 2016 at 07:06:28AM -0600, Bruce Rogers wrote:
> >>> On 3/29/2016 at 08:50 AM, "Daniel P. Berrange" <berrange@redhat.com> wrote: 
> > Support for the PBKDF functions in nettle was not introduced
> > until version 2.6. Some distros QEMU targets have older
> > versions and thus lack PBKDF support. Address this by doing
> > a check in configure for the desired function and then skipping
> > compilation of the nettle-pbkdf.o module
> > 
> > Reported-by: Wen Congyang <wency@cn.fujitsu.com>
> > Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> > ---
> >  configure            | 16 ++++++++++++++++
> >  crypto/Makefile.objs |  4 ++--
> >  2 files changed, 18 insertions(+), 2 deletions(-)
> > 
> > diff --git a/configure b/configure
> > index f4a03b8..2d78bcd 100755
> > --- a/configure
> > +++ b/configure
> > @@ -308,6 +308,7 @@ gnutls=""
> >  gnutls_hash=""
> >  gnutls_rnd=""
> >  nettle=""
> > +nettle_kdf="no"
> >  gcrypt=""
> >  gcrypt_kdf="no"
> >  vte=""
> > @@ -2335,6 +2336,17 @@ if test "$nettle" != "no"; then
> >          libs_tools="$nettle_libs $libs_tools"
> >          QEMU_CFLAGS="$QEMU_CFLAGS $nettle_cflags"
> >          nettle="yes"
> > +
> > +        cat > $TMPC << EOF
> > +#include <nettle/pbkdf2.h>
> > +int main(void) {
> > +     pbkdf2_hmac_sha256(8, NULL, 1000, 8, NULL, 8, NULL);
> > +     return 0;
> > +}
> > +EOF
> > +        if compile_prog "$nettle_cflags" "$nettle_libs" ; then
> > +            nettle_kdf=yes
> > +        fi
> >      else
> >          if test "$nettle" = "yes"; then
> >              feature_not_found "nettle" "Install nettle devel"
> > @@ -4746,6 +4758,7 @@ if test "$nettle" = "yes"; then
> >  else
> >      echo "nettle            $nettle"
> >  fi
> > +echo "nettle kdf        $nettle_kdf"
> >  echo "libtasn1          $tasn1"
> >  echo "VTE support       $vte"
> >  echo "curses support    $curses"
> > @@ -5130,6 +5143,9 @@ fi
> >  if test "$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" >> $config_host_mak
> > diff --git a/crypto/Makefile.objs b/crypto/Makefile.objs
> > index 9f2c87e..0737f48 100644
> > --- a/crypto/Makefile.objs
> > +++ b/crypto/Makefile.objs
> > @@ -11,8 +11,8 @@ crypto-obj-y += secret.o
> >  crypto-obj-$(CONFIG_GCRYPT) += random-gcrypt.o
> >  crypto-obj-$(if $(CONFIG_GCRYPT),n,$(CONFIG_GNUTLS_RND)) += random-gnutls.o
> >  crypto-obj-y += pbkdf.o
> > -crypto-obj-$(CONFIG_NETTLE) += pbkdf-nettle.o
> > -crypto-obj-$(if $(CONFIG_NETTLE),n,$(CONFIG_GCRYPT_KDF)) += pbkdf-gcrypt.o
> > +crypto-obj-$(CONFIG_NETTLE_KDF) += pbkdf-nettle.o
> > +crypto-obj-$(if $(CONFIG_NETTLE_KDF),n,$(CONFIG_GCRYPT_KDF)) += pbkdf-gcrypt.o
> >  crypto-obj-y += ivgen.o
> >  crypto-obj-y += ivgen-essiv.o
> >  crypto-obj-y += ivgen-plain.o
> 
> Do we also need a corresponding fix in tests/Makefile for the inclusion of
> tests/test-crypto-pbkdf ?

Yes, I should have changed that too. Will CC you on a likely fix.


Regards,
Daniel
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