Add signature verification middleware.

Cargo.lock

@@ -339,6 +339,7 @@ checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
 dependencies = [
  "block-buffer",
  "crypto-common",
+ "subtle",
 ]
 
 [[package]]
@@ -567,6 +568,15 @@ version = "0.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d231dfb89cfffdbc30e7fc41579ed6066ad03abda9e567ccafae602b97ec5024"
 
+[[package]]
+name = "hmac"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6c49c37c09c17a53d937dfbb742eb3a961d65a994e6bcdcf37e7399d0cc8ab5e"
+dependencies = [
+ "digest",
+]
+
 [[package]]
 name = "home"
 version = "0.5.9"
@@ -1890,10 +1900,14 @@ name = "webhook_bridge"
 version = "0.0.1"
 dependencies = [
  "axum",
+ "base64 0.22.1",
+ "hmac",
+ "http-body-util",
  "k8s-openapi",
  "kube",
  "serde",
  "serde_json",
+ "sha2",
  "tokio",
  "tower-http",
  "tracing",