diff --git a/http-signature-normalization-actix/Cargo.toml b/http-signature-normalization-actix/Cargo.toml
index 83bcffe..8885e48 100644
--- a/http-signature-normalization-actix/Cargo.toml
+++ b/http-signature-normalization-actix/Cargo.toml
@@ -11,12 +11,25 @@ edition = "2018"
 [features]
 default = []
 digest = ["base64", "futures"]
+sha-2 = ["digest", "sha2"]
+sha-3 = ["digest", "sha3"]
+
+[[example]]
+name = "server"
+required-features = ["sha-2"]
+
+[[example]]
+name = "client"
+required-features = ["sha-2"]
 
 [dependencies]
 actix-web = "1.0"
 base64 = { version = "0.10", optional = true }
-http-signature-normalization = { version = "0.1.0", path = ".." }
+failure = "0.1"
 futures = { version = "0.1", optional = true }
+http-signature-normalization = { version = "0.1.0", path = ".." }
+sha2 = { version = "0.8", optional = true }
+sha3 = { version = "0.8", optional = true }
 
 [dev-dependencies]
 actix = "0.8"
diff --git a/http-signature-normalization-actix/examples/client.rs b/http-signature-normalization-actix/examples/client.rs
index 15178cb..a1ee1b9 100644
--- a/http-signature-normalization-actix/examples/client.rs
+++ b/http-signature-normalization-actix/examples/client.rs
@@ -2,18 +2,24 @@ use actix::System;
 use actix_web::client::Client;
 use futures::future::{lazy, Future};
 use http_signature_normalization_actix::prelude::*;
+use sha2::{Digest, Sha256};
 
 fn main() {
     System::new("client-example")
         .block_on(lazy(|| {
             let config = Config::default();
+            let mut digest = Sha256::new();
 
             Client::default()
-                .get("http://127.0.0.1:8010/")
+                .post("http://127.0.0.1:8010/")
                 .header("User-Agent", "Actix Web")
-                .authorization_signature::<_, MyError, _>(&config, "my-key-id", |s| {
-                    Ok(s.as_bytes().to_vec())
-                })
+                .authorization_signature_with_digest::<_, MyError, _, _, _>(
+                    &config,
+                    "my-key-id",
+                    &mut digest,
+                    "Hewwo owo",
+                    |s| Ok(s.as_bytes().to_vec()),
+                )
                 .unwrap()
                 .send()
                 .map_err(|_| ())
diff --git a/http-signature-normalization-actix/examples/server.rs b/http-signature-normalization-actix/examples/server.rs
index c11f6b4..7eb91e6 100644
--- a/http-signature-normalization-actix/examples/server.rs
+++ b/http-signature-normalization-actix/examples/server.rs
@@ -1,6 +1,7 @@
 use actix::System;
 use actix_web::{web, App, HttpRequest, HttpServer, ResponseError};
 use http_signature_normalization_actix::{prelude::*, verify::Algorithm};
+use sha2::{Digest, Sha256};
 use std::fmt;
 
 fn index((req, config): (HttpRequest, web::Data<Config>)) -> Result<&'static str, MyError> {
@@ -26,7 +27,8 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     HttpServer::new(move || {
         App::new()
             .data(Config::default())
-            .route("/", web::get().to(index))
+            .wrap(VerifyDigest::new(Sha256::new()))
+            .route("/", web::post().to(index))
     })
     .bind("127.0.0.1:8010")?
     .start();
diff --git a/http-signature-normalization-actix/src/digest/middleware.rs b/http-signature-normalization-actix/src/digest/middleware.rs
new file mode 100644
index 0000000..5f568ea
--- /dev/null
+++ b/http-signature-normalization-actix/src/digest/middleware.rs
@@ -0,0 +1,165 @@
+use actix_web::{
+    dev::{Body, Service, ServiceRequest, ServiceResponse, Transform},
+    error::PayloadError,
+    http::header::HeaderValue,
+    web::Bytes,
+    HttpMessage, HttpResponse, ResponseError,
+};
+use failure::Fail;
+use futures::{
+    future::{err, ok, Either, FutureResult},
+    stream::once,
+    Future, Poll, Stream,
+};
+use std::{cell::RefCell, rc::Rc};
+
+use super::{DigestPart, DigestVerify};
+
+pub struct VerifyDigest<T>(bool, T);
+pub struct VerifyMiddleware<T, S>(Rc<RefCell<S>>, bool, T);
+
+#[derive(Debug, Fail)]
+#[fail(display = "Error in upstream middleware")]
+pub struct UpstreamError;
+
+#[derive(Debug, Fail)]
+#[fail(display = "Error verifying digest")]
+pub struct VerifyError;
+
+impl<T> VerifyDigest<T>
+where
+    T: DigestVerify + Clone,
+{
+    pub fn new(verify_digest: T) -> Self {
+        VerifyDigest(true, verify_digest)
+    }
+
+    pub fn optional(self) -> Self {
+        VerifyDigest(false, self.1)
+    }
+}
+
+impl<T, S> Transform<S> for VerifyDigest<T>
+where
+    T: DigestVerify + Clone + 'static,
+    S: Service<Request = ServiceRequest, Response = ServiceResponse<Body>> + 'static,
+    S::Error: 'static,
+{
+    type Request = ServiceRequest;
+    type Response = ServiceResponse<Body>;
+    type Error = actix_web::Error;
+    type Transform = VerifyMiddleware<T, S>;
+    type InitError = ();
+    type Future = FutureResult<Self::Transform, Self::InitError>;
+
+    fn new_transform(&self, service: S) -> Self::Future {
+        ok(VerifyMiddleware(
+            Rc::new(RefCell::new(service)),
+            self.0,
+            self.1.clone(),
+        ))
+    }
+}
+
+impl<T, S> Service for VerifyMiddleware<T, S>
+where
+    T: DigestVerify + Clone + 'static,
+    S: Service<Request = ServiceRequest, Response = ServiceResponse<Body>> + 'static,
+    S::Error: 'static,
+{
+    type Request = ServiceRequest;
+    type Response = ServiceResponse<Body>;
+    type Error = actix_web::Error;
+    type Future = Box<dyn Future<Item = Self::Response, Error = Self::Error>>;
+
+    fn poll_ready(&mut self) -> Poll<(), Self::Error> {
+        self.0
+            .borrow_mut()
+            .poll_ready()
+            .map_err(|_| UpstreamError.into())
+    }
+
+    fn call(&mut self, mut req: ServiceRequest) -> Self::Future {
+        let mut verify_digest = self.2.clone();
+        if let Some(digest) = req.headers().get("Digest") {
+            let vec = match parse_digest(digest) {
+                Some(vec) => vec,
+                None => return Box::new(err(VerifyError.into())),
+            };
+            let payload = req.take_payload();
+            let service = self.0.clone();
+
+            Box::new(payload.concat2().from_err().and_then(move |bytes| {
+                if verify_digest.verify(&vec, &bytes.as_ref()) {
+                    req.set_payload(
+                        (Box::new(once(Ok(bytes)))
+                            as Box<dyn Stream<Item = Bytes, Error = PayloadError>>)
+                            .into(),
+                    );
+
+                    Either::A(
+                        service
+                            .borrow_mut()
+                            .call(req)
+                            .map_err(|_| UpstreamError.into()),
+                    )
+                } else {
+                    Either::B(err(VerifyError.into()))
+                }
+            }))
+        } else {
+            if self.1 {
+                Box::new(err(VerifyError.into()))
+            } else {
+                Box::new(
+                    self.0
+                        .borrow_mut()
+                        .call(req)
+                        .map_err(|_| UpstreamError.into()),
+                )
+            }
+        }
+    }
+}
+
+fn parse_digest(h: &HeaderValue) -> Option<Vec<DigestPart>> {
+    let h = h.to_str().ok()?.split(";").next()?;
+    let v: Vec<_> = h
+        .split(",")
+        .filter_map(|p| {
+            let mut iter = p.splitn(2, "=");
+            iter.next()
+                .and_then(|alg| iter.next().map(|value| (alg, value)))
+        })
+        .map(|(alg, value)| DigestPart {
+            algorithm: alg.to_owned(),
+            digest: value.to_owned(),
+        })
+        .collect();
+
+    if v.is_empty() {
+        None
+    } else {
+        Some(v)
+    }
+}
+
+impl ResponseError for UpstreamError {
+    fn error_response(&self) -> HttpResponse {
+        HttpResponse::InternalServerError().finish()
+    }
+
+    fn render_response(&self) -> HttpResponse {
+        Self::error_response(self)
+    }
+}
+
+impl ResponseError for VerifyError {
+    fn error_response(&self) -> HttpResponse {
+        HttpResponse::BadRequest().finish()
+    }
+
+    fn render_response(&self) -> HttpResponse {
+        Self::error_response(self)
+    }
+}
diff --git a/http-signature-normalization-actix/src/digest/mod.rs b/http-signature-normalization-actix/src/digest/mod.rs
new file mode 100644
index 0000000..51c5244
--- /dev/null
+++ b/http-signature-normalization-actix/src/digest/mod.rs
@@ -0,0 +1,87 @@
+use actix_web::{
+    client::{ClientRequest, ClientResponse},
+    error::PayloadError,
+    http::header::{InvalidHeaderValue, ToStrError},
+    web::Bytes,
+};
+use futures::{Future, Stream};
+use std::fmt::Display;
+
+use crate::{Config, Sign};
+
+pub mod middleware;
+#[cfg(feature = "sha-2")]
+pub mod sha2;
+#[cfg(feature = "sha-3")]
+pub mod sha3;
+
+mod sign;
+
+pub trait DigestCreate {
+    const NAME: &'static str;
+
+    fn compute(&mut self, input: &[u8]) -> String;
+}
+
+pub trait DigestVerify {
+    fn verify(&mut self, digests: &[DigestPart], payload: &[u8]) -> bool;
+}
+
+pub trait SignExt: Sign {
+    fn authorization_signature_with_digest<F, E, K, D, V>(
+        self,
+        config: &Config,
+        key_id: K,
+        digest: &mut D,
+        v: V,
+        f: F,
+    ) -> Result<DigestClient<V>, E>
+    where
+        F: FnOnce(&str) -> Result<Vec<u8>, E>,
+        E: From<ToStrError> + From<InvalidHeaderValue>,
+        K: Display,
+        D: DigestCreate,
+        V: AsRef<[u8]>,
+        Self: Sized;
+
+    fn signature_with_digest<F, E, K, D, V>(
+        self,
+        config: &Config,
+        key_id: K,
+        digest: &mut D,
+        v: V,
+        f: F,
+    ) -> Result<DigestClient<V>, E>
+    where
+        F: FnOnce(&str) -> Result<Vec<u8>, E>,
+        E: From<ToStrError> + From<InvalidHeaderValue>,
+        K: Display,
+        D: DigestCreate,
+        V: AsRef<[u8]>,
+        Self: Sized;
+}
+
+pub struct DigestPart {
+    pub algorithm: String,
+    pub digest: String,
+}
+
+pub struct DigestClient<V> {
+    req: ClientRequest,
+    body: V,
+}
+
+impl<V> DigestClient<V>
+where
+    V: AsRef<[u8]>,
+{
+    pub fn new(req: ClientRequest, body: V) -> Self {
+        DigestClient { req, body }
+    }
+
+    pub fn send(
+        self,
+    ) -> impl Future<Item = ClientResponse<impl Stream<Item = Bytes, Error = PayloadError>>> {
+        self.req.send_body(self.body.as_ref().to_vec())
+    }
+}
diff --git a/http-signature-normalization-actix/src/digest/sha2.rs b/http-signature-normalization-actix/src/digest/sha2.rs
new file mode 100644
index 0000000..aa8c58d
--- /dev/null
+++ b/http-signature-normalization-actix/src/digest/sha2.rs
@@ -0,0 +1,153 @@
+use sha2::{Digest as _, Sha224, Sha256, Sha384, Sha512, Sha512Trunc224, Sha512Trunc256};
+
+use super::{DigestCreate, DigestPart, DigestVerify};
+
+impl DigestCreate for Sha224 {
+    const NAME: &'static str = "sha-224";
+
+    fn compute(&mut self, input: &[u8]) -> String {
+        self.input(input);
+        base64::encode(&self.result_reset())
+    }
+}
+
+impl DigestVerify for Sha224 {
+    fn verify(&mut self, parts: &[DigestPart], bytes: &[u8]) -> bool {
+        if let Some(part) = parts
+            .iter()
+            .find(|p| p.algorithm == <Self as DigestCreate>::NAME)
+        {
+            self.input(bytes);
+            let digest = base64::encode(&self.result_reset());
+
+            return part.digest == digest;
+        }
+
+        false
+    }
+}
+
+impl DigestCreate for Sha256 {
+    const NAME: &'static str = "sha-256";
+
+    fn compute(&mut self, input: &[u8]) -> String {
+        self.input(input);
+        base64::encode(&self.result_reset())
+    }
+}
+
+impl DigestVerify for Sha256 {
+    fn verify(&mut self, parts: &[DigestPart], bytes: &[u8]) -> bool {
+        if let Some(part) = parts
+            .iter()
+            .find(|p| p.algorithm == <Self as DigestCreate>::NAME)
+        {
+            self.input(bytes);
+            let digest = base64::encode(&self.result_reset());
+
+            return part.digest == digest;
+        }
+
+        false
+    }
+}
+
+impl DigestCreate for Sha384 {
+    const NAME: &'static str = "sha-384";
+
+    fn compute(&mut self, input: &[u8]) -> String {
+        self.input(input);
+        base64::encode(&self.result_reset())
+    }
+}
+
+impl DigestVerify for Sha384 {
+    fn verify(&mut self, parts: &[DigestPart], bytes: &[u8]) -> bool {
+        if let Some(part) = parts
+            .iter()
+            .find(|p| p.algorithm == <Self as DigestCreate>::NAME)
+        {
+            self.input(bytes);
+            let digest = base64::encode(&self.result_reset());
+
+            return part.digest == digest;
+        }
+
+        false
+    }
+}
+
+impl DigestCreate for Sha512 {
+    const NAME: &'static str = "sha-512";
+
+    fn compute(&mut self, input: &[u8]) -> String {
+        self.input(input);
+        base64::encode(&self.result_reset())
+    }
+}
+
+impl DigestVerify for Sha512 {
+    fn verify(&mut self, parts: &[DigestPart], bytes: &[u8]) -> bool {
+        if let Some(part) = parts
+            .iter()
+            .find(|p| p.algorithm == <Self as DigestCreate>::NAME)
+        {
+            self.input(bytes);
+            let digest = base64::encode(&self.result_reset());
+
+            return part.digest == digest;
+        }
+
+        false
+    }
+}
+
+impl DigestCreate for Sha512Trunc224 {
+    const NAME: &'static str = "sha-512-224";
+
+    fn compute(&mut self, input: &[u8]) -> String {
+        self.input(input);
+        base64::encode(&self.result_reset())
+    }
+}
+
+impl DigestVerify for Sha512Trunc224 {
+    fn verify(&mut self, parts: &[DigestPart], bytes: &[u8]) -> bool {
+        if let Some(part) = parts
+            .iter()
+            .find(|p| p.algorithm == <Self as DigestCreate>::NAME)
+        {
+            self.input(bytes);
+            let digest = base64::encode(&self.result_reset());
+
+            return part.digest == digest;
+        }
+
+        false
+    }
+}
+
+impl DigestCreate for Sha512Trunc256 {
+    const NAME: &'static str = "sha-512-256";
+
+    fn compute(&mut self, input: &[u8]) -> String {
+        self.input(input);
+        base64::encode(&self.result_reset())
+    }
+}
+
+impl DigestVerify for Sha512Trunc256 {
+    fn verify(&mut self, parts: &[DigestPart], bytes: &[u8]) -> bool {
+        if let Some(part) = parts
+            .iter()
+            .find(|p| p.algorithm == <Self as DigestCreate>::NAME)
+        {
+            self.input(bytes);
+            let digest = base64::encode(&self.result_reset());
+
+            return part.digest == digest;
+        }
+
+        false
+    }
+}
diff --git a/http-signature-normalization-actix/src/digest/sha3.rs b/http-signature-normalization-actix/src/digest/sha3.rs
new file mode 100644
index 0000000..e671032
--- /dev/null
+++ b/http-signature-normalization-actix/src/digest/sha3.rs
@@ -0,0 +1,231 @@
+use sha3::{
+    Digest as _, Keccak224, Keccak256, Keccak256Full, Keccak384, Keccak512, Sha3_224, Sha3_256,
+    Sha3_384, Sha3_512,
+};
+
+use super::{DigestCreate, DigestPart, DigestVerify};
+
+impl DigestCreate for Sha3_224 {
+    const NAME: &'static str = "sha3-224";
+
+    fn compute(&mut self, input: &[u8]) -> String {
+        self.input(input);
+        base64::encode(&self.result_reset())
+    }
+}
+
+impl DigestVerify for Sha3_224 {
+    fn verify(&mut self, parts: &[DigestPart], bytes: &[u8]) -> bool {
+        if let Some(part) = parts
+            .iter()
+            .find(|p| p.algorithm == <Self as DigestCreate>::NAME)
+        {
+            self.input(bytes);
+            let digest = base64::encode(&self.result_reset());
+
+            return part.digest == digest;
+        }
+
+        false
+    }
+}
+
+impl DigestCreate for Sha3_256 {
+    const NAME: &'static str = "sha3-256";
+
+    fn compute(&mut self, input: &[u8]) -> String {
+        self.input(input);
+        base64::encode(&self.result_reset())
+    }
+}
+
+impl DigestVerify for Sha3_256 {
+    fn verify(&mut self, parts: &[DigestPart], bytes: &[u8]) -> bool {
+        if let Some(part) = parts
+            .iter()
+            .find(|p| p.algorithm == <Self as DigestCreate>::NAME)
+        {
+            self.input(bytes);
+            let digest = base64::encode(&self.result_reset());
+
+            return part.digest == digest;
+        }
+
+        false
+    }
+}
+
+impl DigestCreate for Sha3_384 {
+    const NAME: &'static str = "sha3-384";
+
+    fn compute(&mut self, input: &[u8]) -> String {
+        self.input(input);
+        base64::encode(&self.result_reset())
+    }
+}
+
+impl DigestVerify for Sha3_384 {
+    fn verify(&mut self, parts: &[DigestPart], bytes: &[u8]) -> bool {
+        if let Some(part) = parts
+            .iter()
+            .find(|p| p.algorithm == <Self as DigestCreate>::NAME)
+        {
+            self.input(bytes);
+            let digest = base64::encode(&self.result_reset());
+
+            return part.digest == digest;
+        }
+
+        false
+    }
+}
+
+impl DigestCreate for Sha3_512 {
+    const NAME: &'static str = "sha3-512";
+
+    fn compute(&mut self, input: &[u8]) -> String {
+        self.input(input);
+        base64::encode(&self.result_reset())
+    }
+}
+
+impl DigestVerify for Sha3_512 {
+    fn verify(&mut self, parts: &[DigestPart], bytes: &[u8]) -> bool {
+        if let Some(part) = parts
+            .iter()
+            .find(|p| p.algorithm == <Self as DigestCreate>::NAME)
+        {
+            self.input(bytes);
+            let digest = base64::encode(&self.result_reset());
+
+            return part.digest == digest;
+        }
+
+        false
+    }
+}
+
+impl DigestCreate for Keccak224 {
+    const NAME: &'static str = "keccak-224";
+
+    fn compute(&mut self, input: &[u8]) -> String {
+        self.input(input);
+        base64::encode(&self.result_reset())
+    }
+}
+
+impl DigestVerify for Keccak224 {
+    fn verify(&mut self, parts: &[DigestPart], bytes: &[u8]) -> bool {
+        if let Some(part) = parts
+            .iter()
+            .find(|p| p.algorithm == <Self as DigestCreate>::NAME)
+        {
+            self.input(bytes);
+            let digest = base64::encode(&self.result_reset());
+
+            return part.digest == digest;
+        }
+
+        false
+    }
+}
+
+impl DigestCreate for Keccak256 {
+    const NAME: &'static str = "keccak-256";
+
+    fn compute(&mut self, input: &[u8]) -> String {
+        self.input(input);
+        base64::encode(&self.result_reset())
+    }
+}
+
+impl DigestVerify for Keccak256 {
+    fn verify(&mut self, parts: &[DigestPart], bytes: &[u8]) -> bool {
+        if let Some(part) = parts
+            .iter()
+            .find(|p| p.algorithm == <Self as DigestCreate>::NAME)
+        {
+            self.input(bytes);
+            let digest = base64::encode(&self.result_reset());
+
+            return part.digest == digest;
+        }
+
+        false
+    }
+}
+
+impl DigestCreate for Keccak256Full {
+    const NAME: &'static str = "keccak-256-full";
+
+    fn compute(&mut self, input: &[u8]) -> String {
+        self.input(input);
+        base64::encode(&self.result_reset())
+    }
+}
+
+impl DigestVerify for Keccak256Full {
+    fn verify(&mut self, parts: &[DigestPart], bytes: &[u8]) -> bool {
+        if let Some(part) = parts
+            .iter()
+            .find(|p| p.algorithm == <Self as DigestCreate>::NAME)
+        {
+            self.input(bytes);
+            let digest = base64::encode(&self.result_reset());
+
+            return part.digest == digest;
+        }
+
+        false
+    }
+}
+
+impl DigestCreate for Keccak384 {
+    const NAME: &'static str = "keccak-384";
+
+    fn compute(&mut self, input: &[u8]) -> String {
+        self.input(input);
+        base64::encode(&self.result_reset())
+    }
+}
+
+impl DigestVerify for Keccak384 {
+    fn verify(&mut self, parts: &[DigestPart], bytes: &[u8]) -> bool {
+        if let Some(part) = parts
+            .iter()
+            .find(|p| p.algorithm == <Self as DigestCreate>::NAME)
+        {
+            self.input(bytes);
+            let digest = base64::encode(&self.result_reset());
+
+            return part.digest == digest;
+        }
+
+        false
+    }
+}
+
+impl DigestCreate for Keccak512 {
+    const NAME: &'static str = "keccak-512";
+
+    fn compute(&mut self, input: &[u8]) -> String {
+        self.input(input);
+        base64::encode(&self.result_reset())
+    }
+}
+
+impl DigestVerify for Keccak512 {
+    fn verify(&mut self, parts: &[DigestPart], bytes: &[u8]) -> bool {
+        if let Some(part) = parts
+            .iter()
+            .find(|p| p.algorithm == <Self as DigestCreate>::NAME)
+        {
+            self.input(bytes);
+            let digest = base64::encode(&self.result_reset());
+
+            return part.digest == digest;
+        }
+
+        false
+    }
+}
diff --git a/http-signature-normalization-actix/src/digest/sign.rs b/http-signature-normalization-actix/src/digest/sign.rs
new file mode 100644
index 0000000..ce6e0d8
--- /dev/null
+++ b/http-signature-normalization-actix/src/digest/sign.rs
@@ -0,0 +1,58 @@
+use actix_web::{
+    client::ClientRequest,
+    http::header::{InvalidHeaderValue, ToStrError},
+};
+use std::fmt::Display;
+
+use crate::{
+    digest::{DigestClient, DigestCreate, SignExt},
+    Config, Sign,
+};
+
+impl SignExt for ClientRequest {
+    fn authorization_signature_with_digest<F, E, K, D, V>(
+        self,
+        config: &Config,
+        key_id: K,
+        digest: &mut D,
+        v: V,
+        f: F,
+    ) -> Result<DigestClient<V>, E>
+    where
+        F: FnOnce(&str) -> Result<Vec<u8>, E>,
+        E: From<ToStrError> + From<InvalidHeaderValue>,
+        K: Display,
+        D: DigestCreate,
+        V: AsRef<[u8]>,
+        Self: Sized,
+    {
+        let digest = digest.compute(v.as_ref());
+
+        self.set_header("Digest", format!("{}={}", D::NAME, digest))
+            .authorization_signature(config, key_id, f)
+            .map(|c| DigestClient::new(c, v))
+    }
+
+    fn signature_with_digest<F, E, K, D, V>(
+        self,
+        config: &Config,
+        key_id: K,
+        digest: &mut D,
+        v: V,
+        f: F,
+    ) -> Result<DigestClient<V>, E>
+    where
+        F: FnOnce(&str) -> Result<Vec<u8>, E>,
+        E: From<ToStrError> + From<InvalidHeaderValue>,
+        K: Display,
+        D: DigestCreate,
+        V: AsRef<[u8]>,
+        Self: Sized,
+    {
+        let digest = digest.compute(v.as_ref());
+
+        self.set_header("Digest", format!("{}={}", D::NAME, digest))
+            .signature(config, key_id, f)
+            .map(|c| DigestClient::new(c, v))
+    }
+}
diff --git a/http-signature-normalization-actix/src/lib.rs b/http-signature-normalization-actix/src/lib.rs
index a25cd3c..c362a8d 100644
--- a/http-signature-normalization-actix/src/lib.rs
+++ b/http-signature-normalization-actix/src/lib.rs
@@ -1,12 +1,7 @@
-use actix_web::{
-    client::ClientRequest,
-    dev::ServiceRequest,
-    http::{
-        header::{HeaderMap, InvalidHeaderValue, ToStrError},
-        uri::PathAndQuery,
-        Method,
-    },
-    HttpRequest,
+use actix_web::http::{
+    header::{HeaderMap, InvalidHeaderValue, ToStrError},
+    uri::PathAndQuery,
+    Method,
 };
 use std::{
     collections::BTreeMap,
@@ -14,40 +9,26 @@ use std::{
     fmt::{self, Display},
 };
 
-#[cfg(feature = "digest")]
-use actix_web::{client::ClientResponse, error::PayloadError, web::Bytes};
-#[cfg(feature = "digest")]
-use futures::{Future, Stream};
+mod sign;
 
+#[cfg(feature = "digest")]
+pub mod digest;
+
+pub mod verify;
 pub mod prelude {
     pub use crate::{verify::Unverified, Config, Sign, Verify, VerifyError};
 
     #[cfg(feature = "digest")]
-    pub use crate::Digest;
+    pub use crate::digest::{
+        middleware::VerifyDigest, DigestClient, DigestCreate, DigestPart, DigestVerify, SignExt,
+    };
 
     pub use actix_web::http::header::{InvalidHeaderValue, ToStrError};
 }
 
 pub mod create;
 
-pub mod verify {
-    pub use http_signature_normalization::verify::{
-        Algorithm, DeprecatedAlgorithm, ParseSignatureError, ParsedHeader, Unvalidated, Unverified,
-        ValidateError,
-    };
-}
-
-use self::{
-    create::{Signed, Unsigned},
-    verify::Unverified,
-};
-
-#[cfg(feature = "digest")]
-pub trait Digest {
-    const NAME: &'static str;
-
-    fn compute(input: &[u8]) -> Vec<u8>;
-}
+use self::{create::Unsigned, verify::Unverified};
 
 pub trait Verify {
     fn begin_verify(&self, config: &Config) -> Result<Unverified, VerifyError>;
@@ -67,38 +48,6 @@ pub trait Sign {
         E: From<ToStrError> + From<InvalidHeaderValue>,
         K: Display,
         Self: Sized;
-
-    #[cfg(feature = "digest")]
-    fn authorization_signature_with_digest<F, E, K, D, V>(
-        self,
-        config: &Config,
-        key_id: K,
-        f: F,
-        v: V,
-    ) -> Result<DigestClient<V>, E>
-    where
-        F: FnOnce(&str) -> Result<Vec<u8>, E>,
-        E: From<ToStrError> + From<InvalidHeaderValue>,
-        K: Display,
-        D: Digest,
-        V: AsRef<[u8]>,
-        Self: Sized;
-
-    #[cfg(feature = "digest")]
-    fn signature_with_digest<F, E, K, D, V>(
-        self,
-        config: &Config,
-        key_id: K,
-        f: F,
-        v: V,
-    ) -> Result<DigestClient<V>, E>
-    where
-        F: FnOnce(&str) -> Result<Vec<u8>, E>,
-        E: From<ToStrError> + From<InvalidHeaderValue>,
-        K: Display,
-        D: Digest,
-        V: AsRef<[u8]>,
-        Self: Sized;
 }
 
 #[derive(Clone, Default)]
@@ -106,28 +55,6 @@ pub struct Config {
     pub config: http_signature_normalization::Config,
 }
 
-#[cfg(feature = "digest")]
-pub struct DigestClient<V> {
-    req: ClientRequest,
-    body: V,
-}
-
-#[cfg(feature = "digest")]
-impl<V> DigestClient<V>
-where
-    V: AsRef<[u8]>,
-{
-    pub fn new(req: ClientRequest, body: V) -> Self {
-        DigestClient { req, body }
-    }
-
-    pub fn send(
-        self,
-    ) -> impl Future<Item = ClientResponse<impl Stream<Item = Bytes, Error = PayloadError>>> {
-        self.req.send_body(self.body.as_ref().to_vec())
-    }
-}
-
 #[derive(Debug)]
 pub enum VerifyError {
     Sig(http_signature_normalization::VerifyError),
@@ -180,120 +107,6 @@ impl Config {
     }
 }
 
-impl Verify for HttpRequest {
-    fn begin_verify(&self, config: &Config) -> Result<Unverified, VerifyError> {
-        config.begin_verify(
-            self.method(),
-            self.uri().path_and_query(),
-            self.headers().clone(),
-        )
-    }
-}
-
-impl Verify for ServiceRequest {
-    fn begin_verify(&self, config: &Config) -> Result<Unverified, VerifyError> {
-        config.begin_verify(
-            self.method(),
-            self.uri().path_and_query(),
-            self.headers().clone(),
-        )
-    }
-}
-
-impl Sign for ClientRequest {
-    fn authorization_signature<F, E, K>(
-        mut self,
-        config: &Config,
-        key_id: K,
-        f: F,
-    ) -> Result<Self, E>
-    where
-        F: FnOnce(&str) -> Result<Vec<u8>, E>,
-        E: From<ToStrError> + From<InvalidHeaderValue>,
-        K: Display,
-    {
-        let signed = prepare(&self, config, key_id, f)?;
-        signed.authorization_header(self.headers_mut())?;
-        Ok(self)
-    }
-
-    fn signature<F, E, K>(mut self, config: &Config, key_id: K, f: F) -> Result<Self, E>
-    where
-        F: FnOnce(&str) -> Result<Vec<u8>, E>,
-        E: From<ToStrError> + From<InvalidHeaderValue>,
-        K: Display,
-    {
-        let signed = prepare(&self, config, key_id, f)?;
-        signed.signature_header(self.headers_mut())?;
-        Ok(self)
-    }
-
-    #[cfg(feature = "digest")]
-    fn authorization_signature_with_digest<F, E, K, D, V>(
-        self,
-        config: &Config,
-        key_id: K,
-        f: F,
-        v: V,
-    ) -> Result<DigestClient<V>, E>
-    where
-        F: FnOnce(&str) -> Result<Vec<u8>, E>,
-        E: From<ToStrError> + From<InvalidHeaderValue>,
-        K: Display,
-        D: Digest,
-        V: AsRef<[u8]>,
-        Self: Sized,
-    {
-        let digest = base64::encode(D::compute(v.as_ref()).as_slice());
-
-        self.set_header("Digest", format!("{}={}", D::NAME, digest))
-            .authorization_signature(config, key_id, f)
-            .map(|c| DigestClient::new(c, v))
-    }
-
-    #[cfg(feature = "digest")]
-    fn signature_with_digest<F, E, K, D, V>(
-        self,
-        config: &Config,
-        key_id: K,
-        f: F,
-        v: V,
-    ) -> Result<DigestClient<V>, E>
-    where
-        F: FnOnce(&str) -> Result<Vec<u8>, E>,
-        E: From<ToStrError> + From<InvalidHeaderValue>,
-        K: Display,
-        D: Digest,
-        V: AsRef<[u8]>,
-        Self: Sized,
-    {
-        let digest = base64::encode(D::compute(v.as_ref()).as_slice());
-
-        self.set_header("Digest", format!("{}={}", D::NAME, digest))
-            .signature(config, key_id, f)
-            .map(|c| DigestClient::new(c, v))
-    }
-}
-
-fn prepare<F, E, K>(request: &ClientRequest, config: &Config, key_id: K, f: F) -> Result<Signed, E>
-where
-    F: FnOnce(&str) -> Result<Vec<u8>, E>,
-    E: From<ToStrError>,
-    K: Display,
-{
-    let unsigned = config.begin_sign(
-        request.get_method(),
-        request.get_uri().path_and_query(),
-        request.headers().clone(),
-    )?;
-
-    let key_id = key_id.to_string();
-
-    let signed = unsigned.sign(key_id, f)?;
-
-    Ok(signed)
-}
-
 impl fmt::Display for VerifyError {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match *self {
diff --git a/http-signature-normalization-actix/src/sign.rs b/http-signature-normalization-actix/src/sign.rs
new file mode 100644
index 0000000..4e7a592
--- /dev/null
+++ b/http-signature-normalization-actix/src/sign.rs
@@ -0,0 +1,55 @@
+use actix_web::{
+    client::ClientRequest,
+    http::header::{InvalidHeaderValue, ToStrError},
+};
+use std::fmt::Display;
+
+use crate::{create::Signed, Config, Sign};
+
+impl Sign for ClientRequest {
+    fn authorization_signature<F, E, K>(
+        mut self,
+        config: &Config,
+        key_id: K,
+        f: F,
+    ) -> Result<Self, E>
+    where
+        F: FnOnce(&str) -> Result<Vec<u8>, E>,
+        E: From<ToStrError> + From<InvalidHeaderValue>,
+        K: Display,
+    {
+        let signed = prepare(&self, config, key_id, f)?;
+        signed.authorization_header(self.headers_mut())?;
+        Ok(self)
+    }
+
+    fn signature<F, E, K>(mut self, config: &Config, key_id: K, f: F) -> Result<Self, E>
+    where
+        F: FnOnce(&str) -> Result<Vec<u8>, E>,
+        E: From<ToStrError> + From<InvalidHeaderValue>,
+        K: Display,
+    {
+        let signed = prepare(&self, config, key_id, f)?;
+        signed.signature_header(self.headers_mut())?;
+        Ok(self)
+    }
+}
+
+fn prepare<F, E, K>(request: &ClientRequest, config: &Config, key_id: K, f: F) -> Result<Signed, E>
+where
+    F: FnOnce(&str) -> Result<Vec<u8>, E>,
+    E: From<ToStrError>,
+    K: Display,
+{
+    let unsigned = config.begin_sign(
+        request.get_method(),
+        request.get_uri().path_and_query(),
+        request.headers().clone(),
+    )?;
+
+    let key_id = key_id.to_string();
+
+    let signed = unsigned.sign(key_id, f)?;
+
+    Ok(signed)
+}
diff --git a/http-signature-normalization-actix/src/verify.rs b/http-signature-normalization-actix/src/verify.rs
new file mode 100644
index 0000000..80fa580
--- /dev/null
+++ b/http-signature-normalization-actix/src/verify.rs
@@ -0,0 +1,27 @@
+use actix_web::{dev::ServiceRequest, HttpRequest};
+pub use http_signature_normalization::verify::{
+    Algorithm, DeprecatedAlgorithm, ParseSignatureError, ParsedHeader, Unvalidated, Unverified,
+    ValidateError,
+};
+
+use crate::{Config, Verify, VerifyError};
+
+impl Verify for HttpRequest {
+    fn begin_verify(&self, config: &Config) -> Result<Unverified, VerifyError> {
+        config.begin_verify(
+            self.method(),
+            self.uri().path_and_query(),
+            self.headers().clone(),
+        )
+    }
+}
+
+impl Verify for ServiceRequest {
+    fn begin_verify(&self, config: &Config) -> Result<Unverified, VerifyError> {
+        config.begin_verify(
+            self.method(),
+            self.uri().path_and_query(),
+            self.headers().clone(),
+        )
+    }
+}