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

[Wen Congyang]

On 03/29/2016 10:50 PM, Daniel P. Berrange 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 <address@hidden>
> Signed-off-by: Daniel P. Berrange <address@hidden>

I build the qemu with this patch. It is OK now.

Thanks
Wen Congyang

> ---
>  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
>