Add digest session cloning

3 files changed, 74 insertions, 0 deletions

diff --git a/include/ncrypto/ncrypto.h b/include/ncrypto/ncrypto.h
index f82cf0e..367ffed 100644
--- a/include/ncrypto/ncrypto.h
+++ b/include/ncrypto/ncrypto.h
@@ -124,6 +124,8 @@ struct ncr_digest_session;
 CK_RV ncr_digest_alloc (struct ncr_digest_session **sess,
 			CK_MECHANISM_TYPE mech);
 CK_RV ncr_digest_free (struct ncr_digest_session *sess);
+CK_RV ncr_digest_clone (struct ncr_digest_session **clone,
+			struct ncr_digest_session *sess);
 /* Use either ncr_digest_{init,update*,final} (), or
    ncr_{digest_init,digest} ().  After finishing such a call sequence, a new
    sequence can be started within the same session. */
diff --git a/lib/ncrypto_local.c b/lib/ncrypto_local.c
index 16bd781..15ae38c 100644
--- a/lib/ncrypto_local.c
+++ b/lib/ncrypto_local.c
@@ -269,6 +269,35 @@ ncr_digest_free (struct ncr_digest_session *sess)
 }
 
 CK_RV
+ncr_digest_clone (struct ncr_digest_session **clone,
+		  struct ncr_digest_session *sess)
+{
+  struct ncr_digest_session *c;
+
+  g_return_val_if_fail (clone != NULL, CKR_ARGUMENTS_BAD);
+  g_return_val_if_fail (sess != NULL, CKR_SESSION_HANDLE_INVALID);
+  g_return_val_if_fail (sess->state == NDS_INITIALIZED
+			|| sess->state == NDS_UPDATED,
+			CKR_OPERATION_NOT_INITIALIZED);
+
+  c = malloc (sizeof (*c));
+  if (c == NULL)
+    return CKR_HOST_MEMORY;
+
+  EVP_MD_CTX_init (&c->ctx);
+  if (EVP_MD_CTX_copy_ex (&c->ctx, &sess->ctx) == 0)
+    {
+      free (c);
+      return ckr_openssl ();
+    }
+  c->state = sess->state;
+  c->md = sess->md;
+  c->md_size = sess->md_size;
+  *clone = c;
+  return CKR_OK;
+}
+
+CK_RV
 ncr_digest_init (struct ncr_digest_session *sess)
 {
   g_return_val_if_fail (sess != NULL, CKR_SESSION_HANDLE_INVALID);
diff --git a/tests/digests.c b/tests/digests.c
index 8013698..d8ca31c 100644
--- a/tests/digests.c
+++ b/tests/digests.c
@@ -142,6 +142,49 @@ main (void)
       assert (res == CKR_OK);
       for (j = 0; j < 2; j++)
 	{
+	  struct ncr_digest_session *clone;
+
+	  res = ncr_digest_init (sess);
+	  assert (res == CKR_OK);
+
+	  res = ncr_digest_update (sess, tvs[i].input, tvs[i].input_size / 2);
+	  assert (res == CKR_OK);
+
+	  res = ncr_digest_clone (&clone, sess);
+	  assert (res == CKR_OK);
+
+	  res = ncr_digest_update (sess, "", 1);
+	  assert (res == CKR_OK);
+
+	  dest_size = sizeof (dest);
+	  res = ncr_digest_final (sess, dest, &dest_size);
+	  assert (res == CKR_OK);
+	  assert (dest_size == tvs[i].output_size);
+	  assert (memcmp (dest, tvs[i].output, dest_size) != 0);
+
+	  res = ncr_digest_update (clone, tvs[i].input + tvs[i].input_size / 2,
+				   tvs[i].input_size - tvs[i].input_size / 2);
+	  assert (res == CKR_OK);
+
+	  dest_size = sizeof (dest);
+	  res = ncr_digest_final (clone, dest, &dest_size);
+	  assert (res == CKR_OK);
+	  assert (dest_size == tvs[i].output_size);
+	  assert (memcmp (dest, tvs[i].output, dest_size) == 0);
+
+	  res = ncr_digest_free (clone);
+	  assert (res == CKR_OK);
+	}
+      res = ncr_digest_free (sess);
+      assert (res == CKR_OK);
+    }
+
+  for (i = 0; i < G_N_ELEMENTS (tvs); i++)
+    {
+      res = ncr_digest_alloc (&sess, tvs[i].mech);
+      assert (res == CKR_OK);
+      for (j = 0; j < 2; j++)
+	{
 	  res = ncr_digest_init (sess);
 	  assert (res == CKR_OK);