Add hCaptcha support.

src/util/captcha.rs

@@ -0,0 +1,42 @@
+use serde::{Serialize, Deserialize};
+use reqwest::blocking::Client;
+use std::collections::HashMap;
+use std::env;
+
+#[derive(Serialize, Deserialize)]
+struct CaptchaResponse {
+    success: bool
+}
+
+pub fn verify(user_token: &Option<String>) -> Result<(), String> {
+    if let Ok(key) = env::var("HCAPTCHA_KEY") {
+        if let Some(token) = user_token {
+            let mut map = HashMap::new();
+            map.insert("secret", key);
+            map.insert("response", token.to_string());
+
+            let client = Client::new();
+            if let Ok(response) = client
+                .post("https://hcaptcha.com/siteverify")
+                .json(&map)
+                .send()
+            {
+                let result: CaptchaResponse = response
+                    .json()
+                    .map_err(|_| "Failed to deserialise captcha result.".to_string())?;
+
+                if result.success {
+                    Ok(())
+                } else {
+                    Err("Unsuccessful captcha verification".to_string())
+                }
+            } else {
+                Err("Failed to verify with hCaptcha".to_string())
+            }
+        } else {
+            Err("Missing hCaptcha token!".to_string())
+        }
+    } else {
+        Ok(())
+    }
+}

src/util/mod.rs

@@ -2,6 +2,8 @@ use hashbrown::HashSet;
 use rand::{distributions::Alphanumeric, Rng};
 use std::iter::FromIterator;
 
+pub mod captcha;
+
 pub fn vec_to_set<T: Clone + Eq + std::hash::Hash>(data: &[T]) -> HashSet<T> {
     HashSet::from_iter(data.iter().cloned())
 }