parlov 0.8.0

HTTP oracle detection tool — systematic probing for RFC-compliant information leakage.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212

//! RFC-compliant elicitation demo server.
//!
//! Implements 7 routes that produce existence oracle signals through genuine
//! business logic: resource lookup first, then constraint validation. Differentials
//! arise because unknown IDs return 404 before validation is ever reached.

#![deny(clippy::all)]

use std::collections::HashMap;
use std::net::SocketAddr;
use std::sync::{Arc, Mutex};

use axum::{
    extract::{Path, State},
    http::{header, HeaderValue, StatusCode},
    response::{IntoResponse, Response},
    routing::{delete, get, patch, post},
    Router,
};
use serde_json::Value;
use tokio::net::TcpListener;

/// IDs the server treats as existing resources.
pub const KNOWN_IDS: &[&str] = &["1", "42", "100"];

/// Email addresses already in use — uniqueness constraint for `/unique/{id}`.
const TAKEN_EMAILS: &[&str] = &["alice@example.com", "bob@example.com"];

/// Valid state machine values for `/state/{id}`.
const VALID_STATES: &[&str] = &["active", "pending", "suspended"];

/// Per-resource request threshold before rate-limiting kicks in.
const RATE_LIMIT_THRESHOLD: u32 = 3;

/// Full-access token value (no scheme prefix) for `/scoped/{id}`.
const FULL_ACCESS_TOKEN: &str = "Bearer full-access";

fn is_known(id: &str) -> bool {
    KNOWN_IDS.contains(&id)
}

/// Shared rate-limit counter: resource ID → request count.
type RateCounter = Arc<Mutex<HashMap<String, u32>>>;

async fn state_machine(
    Path(id): Path<String>,
    body: Option<axum::extract::Json<Value>>,
) -> Response {
    if !is_known(&id) {
        return StatusCode::NOT_FOUND.into_response();
    }
    let Some(axum::extract::Json(json)) = body else {
        return StatusCode::BAD_REQUEST.into_response();
    };
    match json.get("status").and_then(Value::as_str) {
        Some(s) if VALID_STATES.contains(&s) => StatusCode::OK.into_response(),
        Some(_) => StatusCode::CONFLICT.into_response(),
        None => StatusCode::BAD_REQUEST.into_response(),
    }
}

async fn unique(Path(id): Path<String>, body: Option<axum::extract::Json<Value>>) -> Response {
    if !is_known(&id) {
        return StatusCode::NOT_FOUND.into_response();
    }
    let Some(axum::extract::Json(json)) = body else {
        return StatusCode::BAD_REQUEST.into_response();
    };
    match json.get("email").and_then(Value::as_str) {
        Some(email) if TAKEN_EMAILS.contains(&email) => StatusCode::CONFLICT.into_response(),
        Some(_) => StatusCode::CREATED.into_response(),
        None => StatusCode::BAD_REQUEST.into_response(),
    }
}

async fn dependent(Path(id): Path<String>) -> Response {
    if is_known(&id) {
        StatusCode::CONFLICT.into_response()
    } else {
        StatusCode::NOT_FOUND.into_response()
    }
}

async fn ratelimited(Path(id): Path<String>, State(counter): State<RateCounter>) -> Response {
    if !is_known(&id) {
        return StatusCode::NOT_FOUND.into_response();
    }
    let count = {
        let mut map = counter
            .lock()
            .expect("rate counter mutex must not be poisoned");
        let c = map.entry(id).or_insert(0);
        *c += 1;
        *c
    };
    if count > RATE_LIMIT_THRESHOLD {
        let mut resp = StatusCode::TOO_MANY_REQUESTS.into_response();
        resp.headers_mut()
            .insert(header::RETRY_AFTER, HeaderValue::from_static("30"));
        resp
    } else {
        StatusCode::OK.into_response()
    }
}

async fn headered(Path(id): Path<String>) -> Response {
    if !is_known(&id) {
        return StatusCode::NOT_FOUND.into_response();
    }
    let mut resp = StatusCode::OK.into_response();
    let h = resp.headers_mut();
    h.insert("x-ratelimit-limit", HeaderValue::from_static("100"));
    h.insert("x-ratelimit-remaining", HeaderValue::from_static("99"));
    resp
}

async fn forbidden(Path(id): Path<String>, req: axum::http::Request<axum::body::Body>) -> Response {
    if !is_known(&id) {
        return StatusCode::NOT_FOUND.into_response();
    }
    if req.headers().contains_key(header::AUTHORIZATION) {
        StatusCode::FORBIDDEN.into_response()
    } else {
        let mut resp = StatusCode::UNAUTHORIZED.into_response();
        resp.headers_mut().insert(
            header::WWW_AUTHENTICATE,
            HeaderValue::from_static("Bearer realm=\"test\""),
        );
        resp
    }
}

async fn scoped(Path(id): Path<String>, req: axum::http::Request<axum::body::Body>) -> Response {
    if !is_known(&id) {
        return StatusCode::NOT_FOUND.into_response();
    }
    match req
        .headers()
        .get(header::AUTHORIZATION)
        .and_then(|v| v.to_str().ok())
    {
        Some(token) if token == FULL_ACCESS_TOKEN => StatusCode::OK.into_response(),
        Some(_) => StatusCode::FORBIDDEN.into_response(),
        None => {
            let mut resp = StatusCode::UNAUTHORIZED.into_response();
            resp.headers_mut().insert(
                header::WWW_AUTHENTICATE,
                HeaderValue::from_static("Bearer realm=\"test\""),
            );
            resp
        }
    }
}

/// Builds the elicitation demo router with all 7 routes.
pub fn router(counter: RateCounter) -> Router {
    Router::new()
        .route("/state/{id}", patch(state_machine).put(state_machine))
        .route("/unique/{id}", post(unique).put(unique))
        .route("/dependent/{id}", delete(dependent))
        .route("/ratelimited/{id}", get(ratelimited).head(ratelimited))
        .route("/headered/{id}", get(headered).head(headered))
        .route("/forbidden/{id}", get(forbidden).head(forbidden))
        .route("/scoped/{id}", get(scoped).head(scoped))
        .with_state(counter)
}

/// Spawns the RFC-compliant elicitation server on a random port.
///
/// Returns the bound socket address.
///
/// # Panics
///
/// Panics if the OS refuses to bind `127.0.0.1:0` or if `local_addr` cannot be read.
pub async fn spawn() -> SocketAddr {
    let counter: RateCounter = Arc::new(Mutex::new(HashMap::new()));
    let listener = TcpListener::bind("127.0.0.1:0")
        .await
        .expect("failed to bind elicit server listener");
    let addr = listener
        .local_addr()
        .expect("failed to read local_addr from listener");
    tokio::spawn(async move {
        axum::serve(listener, router(counter))
            .await
            .expect("elicit server failed");
    });
    addr
}

/// Spawns the elicitation server on the given port.
///
/// Returns the bound socket address.
///
/// # Panics
///
/// Panics if the OS refuses to bind `127.0.0.1:{port}` or if `local_addr` cannot be read.
pub async fn spawn_on(port: u16) -> SocketAddr {
    let counter: RateCounter = Arc::new(Mutex::new(HashMap::new()));
    let listener = TcpListener::bind(("127.0.0.1", port))
        .await
        .expect("failed to bind elicit server listener");
    let addr = listener
        .local_addr()
        .expect("failed to read local_addr from listener");
    tokio::spawn(async move {
        axum::serve(listener, router(counter))
            .await
            .expect("elicit server failed");
    });
    addr
}