Commit dc2207af authored by Daniel P. Berrangé's avatar Daniel P. Berrangé
Browse files

crypto: add support for nettle's native XTS impl 



Nettle 3.5.0 will add support for the XTS mode. Use this because long
term we wish to delete QEMU's XTS impl to avoid carrying private crypto
algorithm impls.

Unfortunately this degrades nettle performance from 612 MB/s to 568 MB/s
as nettle's XTS impl isn't so well optimized yet.

Reviewed-by: default avatarPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: default avatarStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: default avatarDaniel P. Berrangé <berrange@redhat.com>
parent e0576942

configure

+18 −0
Original line number Diff line number Diff line
@@ -472,6 +472,7 @@ gtk_gl="no" 
tls_priority="NORMAL"

gnutls=""

nettle=""

nettle_xts="no"

gcrypt=""

gcrypt_hmac="no"

gcrypt_xts="no"
@@ -2871,6 +2872,19 @@ if test "$nettle" != "no"; then 
            pass="yes"

        fi

    fi

    if test "$pass" = "yes"

    then

        cat > $TMPC << EOF

#include <nettle/xts.h>

int main(void) {

  return 0;

}

EOF

        if compile_prog "$nettle_cflags" "$nettle_libs" ; then

            nettle_xts=yes

            qemu_private_xts=no

        fi

    fi

    if test "$pass" = "no" && test "$nettle" = "yes"; then

        feature_not_found "nettle" "Install nettle devel >= 2.7.1"

    else
@@ -6346,6 +6360,10 @@ then 
   echo "  XTS             $gcrypt_xts"

fi

echo "nettle            $nettle $(echo_version $nettle $nettle_version)"

if test "$nettle" = "yes"

then

   echo "  XTS             $nettle_xts"

fi

echo "libtasn1          $tasn1"

echo "PAM               $auth_pam"

echo "iconv support     $iconv"

crypto/cipher-nettle.c

+18 −0
Original line number Diff line number Diff line
@@ -19,7 +19,9 @@ 
 */



#include "qemu/osdep.h"

#ifdef CONFIG_QEMU_PRIVATE_XTS

#include "crypto/xts.h"

#endif

#include "cipherpriv.h"



#include <nettle/nettle-types.h>
@@ -30,6 +32,9 @@ 
#include <nettle/serpent.h>

#include <nettle/twofish.h>

#include <nettle/ctr.h>

#ifndef CONFIG_QEMU_PRIVATE_XTS

#include <nettle/xts.h>

#endif



typedef void (*QCryptoCipherNettleFuncWrapper)(const void *ctx,

                                               size_t length,
@@ -626,9 +631,15 @@ qcrypto_nettle_cipher_encrypt(QCryptoCipher *cipher, 
        break;



    case QCRYPTO_CIPHER_MODE_XTS:

#ifdef CONFIG_QEMU_PRIVATE_XTS

        xts_encrypt(ctx->ctx, ctx->ctx_tweak,

                    ctx->alg_encrypt_wrapper, ctx->alg_encrypt_wrapper,

                    ctx->iv, len, out, in);

#else

        xts_encrypt_message(ctx->ctx, ctx->ctx_tweak,

                            ctx->alg_encrypt_native,

                            ctx->iv, len, out, in);

#endif

        break;



    case QCRYPTO_CIPHER_MODE_CTR:
@@ -673,9 +684,16 @@ qcrypto_nettle_cipher_decrypt(QCryptoCipher *cipher, 
        break;



    case QCRYPTO_CIPHER_MODE_XTS:

#ifdef CONFIG_QEMU_PRIVATE_XTS

        xts_decrypt(ctx->ctx, ctx->ctx_tweak,

                    ctx->alg_encrypt_wrapper, ctx->alg_decrypt_wrapper,

                    ctx->iv, len, out, in);

#else

        xts_decrypt_message(ctx->ctx, ctx->ctx_tweak,

                            ctx->alg_decrypt_native,

                            ctx->alg_encrypt_native,

                            ctx->iv, len, out, in);

#endif

        break;

    case QCRYPTO_CIPHER_MODE_CTR:

        ctr_crypt(ctx->ctx, ctx->alg_encrypt_native,