1 files changed, 20 insertions, 0 deletions
diff --git a/openpgp/src/crypto/backend/cng/kdf.rs b/openpgp/src/crypto/backend/cng/kdf.rs
new file mode 100644
index 00000000..ac98a496
--- /dev/null
+++ b/openpgp/src/crypto/backend/cng/kdf.rs
@@ -0,0 +1,20 @@
+use hkdf::Hkdf;
+use sha2::Sha256;
+
+use crate::{
+    Result,
+    crypto::{
+        SessionKey,
+        backend::interface::Kdf,
+    },
+};
+
+impl Kdf for super::Backend {
+    fn hkdf_sha256(ikm: &SessionKey, salt: Option<&[u8]>, info: &[u8],
+                   okm: &mut SessionKey)
+                   -> Result<()>
+    {
+        Ok(Hkdf::<Sha256>::new(salt, &ikm).expand(info, okm)
+           .map_err(|e| crate::Error::InvalidOperation(e.to_string()))?)
+    }
+}