From f7e6dd3246a6bbef768c9a8db5e3293bb91434a7 Mon Sep 17 00:00:00 2001
From: Edward Shen <code@eddie.sh>
Date: Thu, 2 May 2019 03:21:18 -0400
Subject: [PATCH] added body digests checks

---
 Cargo.lock                      |  1 +
 Cargo.toml                      |  1 +
 config/endstat_conf.example.ron |  3 ++-
 src/config.rs                   |  1 +
 src/main.rs                     |  1 +
 src/updater.rs                  | 20 ++++++++++++++++----
 6 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 8235011..f003e59 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -657,6 +657,7 @@ dependencies = [
  "chrono 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "reqwest 0.9.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ring 0.14.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "ron 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.90 (registry+https://github.com/rust-lang/crates.io-index)",
  "tera 0.11.20 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/Cargo.toml b/Cargo.toml
index b4ad378..d31aec5 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,3 +14,4 @@ tokio = "0.1"
 tera = "0.11"
 env_logger = "0.6"
 chrono = { version = "0.4", features = ["serde"] }
+ring = "^0"
diff --git a/config/endstat_conf.example.ron b/config/endstat_conf.example.ron
index 74ae109..0675bb0 100644
--- a/config/endstat_conf.example.ron
+++ b/config/endstat_conf.example.ron
@@ -25,7 +25,8 @@
       endpoints: [
         (label: "Or expect different reponse codes (like 418)", endpoint: "http://error418.net/", code: 418),
         (label: "Or response checking!", endpoint: "http://urlecho.appspot.com/echo", body: "None"),
-        (label: "Or both!", endpoint: "http://urlecho.appspot.com/echo?status=503&Content-Type=text%2Fhtml&body=None", body: "None", code: 503),
+        (label: "Or response hash comparison!", endpoint: "http://urlecho.appspot.com/echo", body_hash: "dc937b59892604f5a86ac96936cd7ff09e25f18ae6b758e8014a24c7fa039e91"),
+        (label: "Or a combination!", endpoint: "http://urlecho.appspot.com/echo?status=503&Content-Type=text%2Fhtml&body=None", body: "None", code: 503),
         (label: "Or expect the endpoint to fail entirely!", endpoint: "http://lol.arpa", should_err: true),
       ],
     ),
diff --git a/src/config.rs b/src/config.rs
index 273af62..b3c4df2 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -7,6 +7,7 @@ pub struct EndpointConfig {
     pub port: Option<u16>,
     pub code: Option<u16>,
     pub body: Option<String>,
+    pub body_hash: Option<String>,
     pub follow_redirects: Option<bool>,
     pub should_err: Option<bool>,
 }
diff --git a/src/main.rs b/src/main.rs
index c6aec79..525d86d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -8,6 +8,7 @@ extern crate serde;
 extern crate tokio;
 #[macro_use]
 extern crate tera;
+extern crate ring;
 
 mod config;
 mod handlers;
diff --git a/src/updater.rs b/src/updater.rs
index 42838e1..69065ce 100644
--- a/src/updater.rs
+++ b/src/updater.rs
@@ -5,6 +5,10 @@ use crate::{
 };
 use chrono::prelude::Utc;
 use reqwest::{Client, RedirectPolicy, Url, UrlError};
+use ring::{
+    digest::{digest, SHA256},
+    test::from_hex,
+};
 use std::time::Duration;
 
 pub fn update_state(state: State) {
@@ -52,11 +56,9 @@ fn get_result(
     match ping_result {
         Ok(mut res) => {
             let res_body = res.text().expect("could not get body of request");
-            let does_code_match = res.status() == code;
-            let does_body_match = body.is_empty() || res_body == body;
             let mut error = None;
 
-            if !does_code_match {
+            if res.status() != code {
                 error = Some(format!(
                     "Status code mismatch: {} != {}.",
                     res.status().as_u16(),
@@ -64,7 +66,17 @@ fn get_result(
                 ));
             }
 
-            if !does_body_match {
+            if let Some(expected_hash) = &endpoint.body_hash {
+                let expected = from_hex(expected_hash).unwrap();
+                let actual = digest(&SHA256, String::from(res_body).as_bytes());
+                if &expected != &actual.as_ref() {
+                    error = Some(if let Some(msg) = error {
+                        format!("{} Body hash mismatch.", msg)
+                    } else {
+                        String::from("Body hash mismatch.")
+                    });
+                }
+            } else if !body.is_empty() && res_body != body {
                 error = Some(if let Some(msg) = error {
                     format!(
                         "{} Body mismatch: {} != {}.",