1 files changed, 18 insertions, 29 deletions

diff --git a/webhook/src/handler/signature.rs b/webhook/src/handler/signature.rs
index c12f9e8..748fa6a 100644
--- a/webhook/src/handler/signature.rs
+++ b/webhook/src/handler/signature.rs
@@ -1,5 +1,8 @@
 use common::prometheus::{Counter, HistogramVec, labels, opts, register_counter, register_histogram_vec};
-use libsodium_sys::crypto_sign_ed25519_verify_detached;
+use ed25519_dalek::PublicKey;
+use ed25519_dalek::Verifier;
+use ed25519_dalek::Signature;
+use std::convert::TryInto;
 
 lazy_static::lazy_static! {
     static ref SIGNATURE_TIME_HISTOGRAM: HistogramVec = register_histogram_vec!(
@@ -8,43 +11,29 @@ lazy_static::lazy_static! {
         &["signature"]
     ).unwrap();
 
-    static ref SIGNATURE_BODY_COUNTER: Counter = register_counter!(opts!(
-        "nova_webhook_",
-        "",
+    static ref SIGNATURE_COUNTER: Counter = register_counter!(opts!(
+        "nova_webhook_signatures_verify",
+        "number of signatures verification issued by the service",
         labels! {"handler" => "webhook_main"}
     )).unwrap();
 }
 
-/// Checks the signature of a given data using the hex signature and the public key.
-pub fn validate_signature(hex_public_key: &str, data: &Vec<u8>, hex_signature: &str) -> bool {
-    SIGNATURE_BODY_COUNTER.inc();
+fn demo<T, const N: usize>(v: Vec<T>) -> [T; N] {
+    v.try_into()
+        .unwrap_or_else(|v: Vec<T>| panic!("Expected a Vec of length {} but it was {}", N, v.len()))
+}
+
+pub fn validate_signature(public_key: &PublicKey, data: &Vec<u8>, hex_signature: &str) -> bool {
+    SIGNATURE_COUNTER.inc();
     let timer = SIGNATURE_TIME_HISTOGRAM.with_label_values(&["webhook_main"]).start_timer();
 
-    // First, we need to check if the signature & private key is valid base64.
     let signature_result = hex::decode(hex_signature);
-    let public_key_result = hex::decode(hex_public_key);
 
     let mut result = false;
-    if signature_result.is_ok() && public_key_result.is_ok() {
-        // Since we now have the signatures in u8 vectors. We will initialize all the
-        // parameters for the ffi call to sodium.
-        let signature_pointer = signature_result.unwrap();
-        let private_key_pointer = public_key_result.unwrap();
-
-        let data_pointer = data.as_ptr();
-        let data_len = data.len() as u64;
-
-        // A ffi call is considered unsafe by the Rust compiler
-        // we assume all the parameters are correct for the call
-        unsafe {
-            // If the signature is valid, sodium will return 0
-            result = crypto_sign_ed25519_verify_detached(
-                signature_pointer.as_ptr(),
-                data_pointer,
-                data_len,
-                private_key_pointer.as_ptr(),
-            ) == 0;
-        }
+    if let Ok(signature) = signature_result {
+        let sig = Signature::from(demo(signature));
+
+        result = public_key.verify(data, &sig).is_ok();
     }
 
     timer.observe_duration();