diff --git a/crates/oxidetalis/src/middlewares/signature.rs b/crates/oxidetalis/src/middlewares/signature.rs
index f108f4a..e5d019b 100644
--- a/crates/oxidetalis/src/middlewares/signature.rs
+++ b/crates/oxidetalis/src/middlewares/signature.rs
@@ -16,10 +16,12 @@
 
 //! Request signature middleware.
 
+use oxidetalis_core::types::{PublicKey, Signature};
 use salvo::{
     handler,
     http::{Body, StatusCode},
     Depot,
+    Extractible,
     FlowCtrl,
     Request,
     Response,
@@ -54,7 +56,7 @@ pub async fn signature_check(
         }
     };
 
-    let signature = match utils::extract_signature(req) {
+    let signature = match Signature::extract(req).await {
         Ok(s) => s,
         Err(err) => {
             write_err(&err.to_string(), UNAUTHORIZED);
@@ -62,7 +64,7 @@ pub async fn signature_check(
         }
     };
 
-    let sender_public_key = match utils::extract_public_key(req) {
+    let sender_public_key = match PublicKey::extract(req).await {
         Ok(k) => k,
         Err(err) => {
             write_err(&err.to_string(), UNAUTHORIZED);
diff --git a/crates/oxidetalis_core/src/types/impl_openapi.rs b/crates/oxidetalis_core/src/types/impl_openapi.rs
index b22fbfe..eea4d05 100644
--- a/crates/oxidetalis_core/src/types/impl_openapi.rs
+++ b/crates/oxidetalis_core/src/types/impl_openapi.rs
@@ -111,20 +111,26 @@ impl EndpointArgRegister for CorePublicKey {
 
 impl<'ex> Extractible<'ex> for Signature {
     fn metadata() -> &'ex ExtractMetadata {
-        unreachable!(
-            "
-            `Extractible` is required to implement `ToParameters` for `Signature`, but \
-             Salvo does not need it actually, see https://github.com/salvo-rs/salvo/issues/838"
-        )
+        static METADATA: ExtractMetadata = ExtractMetadata::new("");
+        &METADATA
     }
 
     #[allow(refining_impl_trait)]
-    async fn extract(_: &'ex mut Request) -> Result<Self, StatusError> {
-        unreachable!(
-            "
-            `Extractible` is required to implement `ToParameters` for `Signature`, but \
-             Salvo does not need it actually, see https://github.com/salvo-rs/salvo/issues/838"
-        )
+    async fn extract(req: &'ex mut Request) -> Result<Self, StatusError> {
+        extract_header(req, crate::SIGNATURE_HEADER)
+            .and_then(|sig| {
+                Signature::from_str(sig).map_err(|err| {
+                    StatusError::unauthorized()
+                        .brief("Invalid signature")
+                        .cause(err.to_string())
+                })
+            })
+            .map_err(|err| {
+                StatusError::unauthorized().brief(err.brief).cause(
+                    err.cause
+                        .expect("The cause was set when we extract the header"),
+                )
+            })
     }
 }