Initial PoC of spoofing Android OAuth

src/oauth.rs

@@ -0,0 +1,53 @@
+use std::collections::HashMap;
+
+use crate::client::CLIENT;
+use base64::{engine::general_purpose, Engine as _};
+use hyper::{client, Body, Method, Request};
+use serde_json::json;
+
+static REDDIT_ANDROID_OAUTH_CLIENT_ID: &str = "ohXpoqrZYub1kg";
+
+static AUTH_ENDPOINT: &str = "https://accounts.reddit.com";
+pub(crate) static USER_AGENT: &str = "Reddit/Version 2023.21.0/Build 956283/Android 13";
+
+pub(crate) struct Oauth {
+	// Currently unused, may be necessary if we decide to support GQL in the future
+	pub(crate) headers_map: HashMap<String, String>,
+	pub(crate) token: String,
+}
+
+impl Oauth {
+	pub fn new() -> Self {
+		let uuid = uuid::Uuid::new_v4().to_string();
+		Oauth {
+			headers_map: HashMap::from([
+				("Client-Vendor-Id".into(), uuid.clone()),
+				("X-Reddit-Device-Id".into(), uuid),
+				("User-Agent".into(), USER_AGENT.to_string()),
+			]),
+			token: String::new(),
+		}
+	}
+	pub async fn login(&mut self) -> Option<()> {
+		let url = format!("{}/api/access_token", AUTH_ENDPOINT);
+		let mut builder = Request::builder().method(Method::POST).uri(&url);
+		for (key, value) in self.headers_map.iter() {
+			builder = builder.header(key, value);
+		}
+
+		let auth = general_purpose::STANDARD.encode(format!("{REDDIT_ANDROID_OAUTH_CLIENT_ID}:"));
+		builder = builder.header("Authorization", format!("Basic {auth}"));
+		let json = json!({
+				"scopes": ["*","email","pii"]
+		});
+		let body = Body::from(json.to_string());
+		let request = builder.body(body).unwrap();
+		let client: client::Client<_, hyper::Body> = CLIENT.clone();
+		let resp = client.request(request).await.ok()?;
+		let body_bytes = hyper::body::to_bytes(resp.into_body()).await.ok()?;
+		let json: serde_json::Value = serde_json::from_slice(&body_bytes).ok()?;
+		self.token = json.get("access_token")?.as_str()?.to_string();
+		self.headers_map.insert("Authorization".to_owned(), format!("Bearer {}", self.token));
+		Some(())
+	}
+}