Add symmetric signature session cloning

1 files changed, 33 insertions, 0 deletions

diff --git a/lib/ncrypto_local.c b/lib/ncrypto_local.c
index 15ae38c..5e0077d 100644
--- a/lib/ncrypto_local.c
+++ b/lib/ncrypto_local.c
@@ -788,6 +788,39 @@ ncr_symm_signature_free (struct ncr_symm_signature_session *sess)
   return CKR_OK;
 }
 
+CK_RV
+ncr_symm_signature_clone (struct ncr_symm_signature_session **clone,
+			  struct ncr_symm_signature_session *sess)
+{
+  struct ncr_symm_signature_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 == NSSS_INITIALIZED
+			|| sess->state == NSSS_UPDATED,
+			CKR_OPERATION_NOT_INITIALIZED);
+
+  c = malloc (sizeof (*c));
+  if (c == NULL)
+    return CKR_HOST_MEMORY;
+
+  /* HMAC_CTX_copy is undocumented, and seems not to need MD_CTX_init, but
+     openssl internally calls HMAC_CTX_init before HMAC_CTX_copy, so we do as
+     well. */
+  HMAC_CTX_init (&c->ctx);
+  if (HMAC_CTX_copy (&c->ctx, &sess->ctx) == 0)
+    {
+      free (c);
+      return ckr_openssl ();
+    }
+  c->state = sess->state;
+  c->md = sess->md;
+  c->md_size = sess->md_size;
+  c->signing = sess->signing;
+  *clone = c;
+  return CKR_OK;
+}
+
 static CK_RV
 symm_signature_init (struct ncr_symm_signature_session *sess, bool sign,
 		     struct ncr_symm_key *key)