diff --git a/Cargo.toml b/Cargo.toml
index 901b475..38b91c5 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -46,3 +46,14 @@ base64 = { version = "0.21.6" }
 
 # for request and response headers
 http = { version = "1.0.0" }
+http-body = { version = "1.0.0" }
+http-body-util = { version = "0.1.0" }
+bytes = { version = "1.5.0" }
+async-trait = "0.1.77"
+
+
+[dev-dependencies]
+tokio = { version = "1.35.1", default-features = false, features = [
+  "macros",
+  "rt-multi-thread",
+] } # testing only?
diff --git a/src/ext/hyper_http.rs b/src/ext/hyper_http.rs
index 1f52a12..99479dc 100644
--- a/src/ext/hyper_http.rs
+++ b/src/ext/hyper_http.rs
@@ -1 +1,201 @@
+use super::{ContentDigestType, CONTENT_DIGEST_HEADER};
+use async_trait::async_trait;
+use base64::{engine::general_purpose, Engine as _};
+use bytes::{Buf, Bytes};
+use http::{Request, Response};
+use http_body::Body;
+use http_body_util::{BodyExt, Full};
+use sha2::Digest;
+
 // hyper's http specific extension to generate and verify http signature
+
+/* --------------------------------------- */
+#[async_trait]
+trait HyperContentDigest: http_body::Body {
+  /// Returns the bytes object of the body
+  async fn into_bytes(self) -> std::result::Result<Bytes, Self::Error>
+  where
+    Self: Sized,
+    Self::Data: Send,
+  {
+    let mut body_buf = self.collect().await?.aggregate();
+    Ok(body_buf.copy_to_bytes(body_buf.remaining()))
+  }
+
+  /// Returns the content digest in base64
+  async fn into_bytes_with_digest(
+    self,
+    cd_type: &ContentDigestType,
+  ) -> std::result::Result<(Bytes, String), Self::Error>
+  where
+    Self: Sized,
+    Self::Data: Send,
+  {
+    let body_bytes = self.into_bytes().await?;
+    let digest = match cd_type {
+      ContentDigestType::Sha256 => {
+        let mut hasher = sha2::Sha256::new();
+        hasher.update(&body_bytes);
+        hasher.finalize().to_vec()
+      }
+
+      ContentDigestType::Sha512 => {
+        let mut hasher = sha2::Sha512::new();
+        hasher.update(&body_bytes);
+        hasher.finalize().to_vec()
+      }
+    };
+
+    Ok((body_bytes, general_purpose::STANDARD.encode(digest)))
+  }
+}
+
+impl<T: ?Sized> HyperContentDigest for T where T: http_body::Body {}
+
+/* --------------------------------------- */
+#[async_trait]
+/// A trait to set the http content digest in request in base64
+pub trait HyperRequestContentDigest {
+  type Error;
+  async fn set_content_digest(
+    self,
+    cd_type: &ContentDigestType,
+  ) -> std::result::Result<Request<Full<Bytes>>, Self::Error>
+  where
+    Self: Sized;
+}
+
+#[async_trait]
+/// A trait to set the http content digest in response in base64
+pub trait HyperResponseContentDigest {
+  type Error;
+  async fn set_content_digest(
+    self,
+    cd_type: &ContentDigestType,
+  ) -> std::result::Result<Response<Full<Bytes>>, Self::Error>
+  where
+    Self: Sized;
+}
+
+#[async_trait]
+impl<B> HyperRequestContentDigest for Request<B>
+where
+  B: Body + Send,
+  <B as Body>::Data: Send,
+{
+  type Error = anyhow::Error;
+
+  async fn set_content_digest(
+    self,
+    cd_type: &ContentDigestType,
+  ) -> std::result::Result<Request<Full<Bytes>>, Self::Error>
+  where
+    Self: Sized,
+  {
+    let (mut parts, body) = self.into_parts();
+    let (body_bytes, digest) = body
+      .into_bytes_with_digest(cd_type)
+      .await
+      .map_err(|_e| anyhow::anyhow!("Failed to generate digest"))?;
+    let new_body = Full::new(body_bytes);
+
+    parts
+      .headers
+      .insert(CONTENT_DIGEST_HEADER, format!("{cd_type}=:{digest}:").parse().unwrap());
+
+    let new_req = Request::from_parts(parts, new_body);
+    Ok(new_req)
+  }
+}
+
+#[async_trait]
+impl<B> HyperResponseContentDigest for Response<B>
+where
+  B: Body + Send,
+  <B as Body>::Data: Send,
+{
+  type Error = anyhow::Error;
+
+  async fn set_content_digest(
+    self,
+    cd_type: &ContentDigestType,
+  ) -> std::result::Result<Response<Full<Bytes>>, Self::Error>
+  where
+    Self: Sized,
+  {
+    let (mut parts, body) = self.into_parts();
+    let (body_bytes, digest) = body
+      .into_bytes_with_digest(cd_type)
+      .await
+      .map_err(|_e| anyhow::anyhow!("Failed to generate digest"))?;
+    let new_body = Full::new(body_bytes);
+
+    parts
+      .headers
+      .insert(CONTENT_DIGEST_HEADER, format!("{cd_type}=:{digest}:").parse().unwrap());
+
+    let new_req = Response::from_parts(parts, new_body);
+    Ok(new_req)
+  }
+}
+
+/* --------------------------------------- */
+#[cfg(test)]
+mod tests {
+  use super::*;
+
+  #[tokio::test]
+  async fn content_digest() {
+    let body = Full::new(&b"{\"hello\": \"world\"}"[..]);
+    let (_body_bytes, digest) = body.into_bytes_with_digest(&ContentDigestType::Sha256).await.unwrap();
+
+    assert_eq!(digest, "X48E9qOokqqrvdts8nOJRJN3OWDUoyWxBf7kbu9DBPE=");
+
+    let (_body_bytes, digest) = body.into_bytes_with_digest(&ContentDigestType::Sha512).await.unwrap();
+    assert_eq!(
+      digest,
+      "WZDPaVn/7XgHaAy8pmojAkGWoRx2UFChF41A2svX+TaPm+AbwAgBWnrIiYllu7BNNyealdVLvRwEmTHWXvJwew=="
+    );
+  }
+
+  #[tokio::test]
+  async fn hyper_request_test() {
+    let body = Full::new(&b"{\"hello\": \"world\"}"[..]);
+
+    let req = Request::builder()
+      .method("GET")
+      .uri("https://example.com/")
+      .header("date", "Sun, 09 May 2021 18:30:00 GMT")
+      .header("content-type", "application/json")
+      .body(body)
+      .unwrap();
+    let req = req.set_content_digest(&ContentDigestType::Sha256).await.unwrap();
+
+    assert!(req.headers().contains_key(CONTENT_DIGEST_HEADER));
+    let digest = req.headers().get(CONTENT_DIGEST_HEADER).unwrap().to_str().unwrap();
+    assert_eq!(
+      digest,
+      format!("sha-256=:X48E9qOokqqrvdts8nOJRJN3OWDUoyWxBf7kbu9DBPE=:")
+    );
+  }
+
+  #[tokio::test]
+  async fn hyper_response_test() {
+    let body = Full::new(&b"{\"hello\": \"world\"}"[..]);
+
+    let res = Response::builder()
+      .status(200)
+      .header("date", "Sun, 09 May 2021 18:30:00 GMT")
+      .header("content-type", "application/json")
+      .body(body)
+      .unwrap();
+    let res = res.set_content_digest(&ContentDigestType::Sha256).await.unwrap();
+
+    assert!(res.headers().contains_key(CONTENT_DIGEST_HEADER));
+    let digest = res.headers().get(CONTENT_DIGEST_HEADER).unwrap().to_str().unwrap();
+    assert_eq!(
+      digest,
+      format!("sha-256=:X48E9qOokqqrvdts8nOJRJN3OWDUoyWxBf7kbu9DBPE=:")
+    );
+  }
+}
diff --git a/src/ext/mod.rs b/src/ext/mod.rs
index e1c413c..ca629c7 100644
--- a/src/ext/mod.rs
+++ b/src/ext/mod.rs
@@ -1 +1,30 @@
 mod hyper_http;
+
+const CONTENT_DIGEST_HEADER: &str = "content-digest";
+
+/// content-digest header type
+pub enum ContentDigestType {
+  Sha256,
+  Sha512,
+}
+
+impl std::fmt::Display for ContentDigestType {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    match self {
+      ContentDigestType::Sha256 => write!(f, "sha-256"),
+      ContentDigestType::Sha512 => write!(f, "sha-512"),
+    }
+  }
+}
+
+// TODO: creating signature base from http header lines and signature params builder config
+
+// TODO: creating signature base from http header lines including signature params
+
+// TODO: These should be given as a trait
+
+// /// A trait to generate the http message signature
+// /// TODO: signature params should be given as a trait
+// pub trait HttpMessageSignature {
+//   fn message_signature(&self) -> String;
+// }
diff --git a/src/signature_base.rs b/src/signature_base.rs
index f17efd4..c2518e3 100644
--- a/src/signature_base.rs
+++ b/src/signature_base.rs
@@ -59,10 +59,6 @@ impl std::fmt::Display for SignatureBase {
   }
 }
 
-// TODO: creating signature base from http header lines and signature params builder config
-
-// TODO: creating signature base from http header lines including signature params
-
 #[cfg(test)]
 mod test {
   use super::*;