[Qemu-devel] [RFC V2 08/20] qcow2: Implement qcow2_compute_cluster_hash.

["Benoît Canet" <benoit@irqsave.net>]

---
 Makefile            |    3 +++
 Makefile.target     |    2 +-
 block/qcow2-dedup.c |   10 ++++++++--
 3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/Makefile b/Makefile
index a9c22bf..b4dab79 100644
--- a/Makefile
+++ b/Makefile
@@ -166,6 +166,9 @@ qemu-img$(EXESUF): qemu-img.o $(tools-obj-y) $(block-obj-y) $(qapi-obj-y) \
                               qapi-visit.o qapi-types.o
 qemu-nbd$(EXESUF): qemu-nbd.o $(tools-obj-y) $(block-obj-y)
 qemu-io$(EXESUF): qemu-io.o cmd.o $(tools-obj-y) $(block-obj-y)
+qemu-img$(EXESUF): LIBS+=-lcrypto
+qemu-nbd$(EXESUF): LIBS+=-lcrypto
+qemu-io$(EXESUF): LIBS+=-lcrypto
 
 qemu-bridge-helper$(EXESUF): qemu-bridge-helper.o
 
diff --git a/Makefile.target b/Makefile.target
index 3822bc5..f9a988a 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -119,7 +119,7 @@ obj-$(CONFIG_HAVE_GET_MEMORY_MAPPING) += memory_mapping.o
 obj-$(CONFIG_HAVE_CORE_DUMP) += dump.o
 obj-$(CONFIG_NO_GET_MEMORY_MAPPING) += memory_mapping-stub.o
 obj-$(CONFIG_NO_CORE_DUMP) += dump-stub.o
-LIBS+=-lz
+LIBS+=-lz -lcrypto
 
 QEMU_CFLAGS += $(VNC_TLS_CFLAGS)
 QEMU_CFLAGS += $(VNC_SASL_CFLAGS)
diff --git a/block/qcow2-dedup.c b/block/qcow2-dedup.c
index 50d61f2..c626720 100644
--- a/block/qcow2-dedup.c
+++ b/block/qcow2-dedup.c
@@ -25,11 +25,13 @@
  * THE SOFTWARE.
  */
 
+#include <openssl/sha.h>
+#include <openssl/evp.h>
 #include "block_int.h"
 #include "qemu-common.h"
 #include "qcow2.h"
 
-#define HASH_LENGTH 32
+#define HASH_LENGTH SHA256_DIGEST_LENGTH
 
 /**
  * Read some data from the QCOW2 file
@@ -217,7 +219,11 @@ static bool qcow2_dedup_insert_hash_in_rb_tree(BlockDriverState *bs,
 static uint8_t *qcow2_compute_cluster_hash(BlockDriverState *bs,
                                            uint8_t *data)
 {
-    return NULL;
+    BDRVQcowState *s = bs->opaque;
+    uint8_t *hash = g_malloc0(HASH_LENGTH);
+    EVP_Digest(data, s->cluster_size,
+               hash, NULL, EVP_sha256(), NULL);
+    return hash;
 }
 
 /* Try to find the offset of a given cluster if it's duplicated
-- 
1.7.10.4