diff --git a/crypto/digest.c b/crypto/digest.c
index 7a8c3c0..bc6de0b 100644
--- a/crypto/digest.c
+++ b/crypto/digest.c
@@ -272,6 +272,9 @@
 			goto out_free;
 		size -= now;
 		len += now;
+
+		if (!flags)
+			buf += now;
 	}
 
 	if (sig)