cedros-login-server 0.0.15

Authentication server for cedros-login with email/password, Google OAuth, and Solana wallet sign-in
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
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289

//! Rate limiting layer and service implementation

use axum::{body::Body, extract::ConnectInfo, http::Request, http::Response};
use std::net::SocketAddr;
use tower::{Layer, Service};

use super::types::{RateLimitBackend, RateLimitConfig, RateLimitError, RateLimitResult};
use crate::utils::extract_client_ip;

/// How to extract the rate limit key from a request
#[derive(Clone)]
pub enum KeyExtractor {
    /// Use IP address only
    IpOnly,
    /// Use IP + path
    IpAndPath,
}

/// Layer for applying rate limiting
#[derive(Clone)]
pub struct RateLimitLayer {
    backend: RateLimitBackend,
    config: RateLimitConfig,
    key_extractor: KeyExtractor,
    trust_proxy: bool,
}

impl RateLimitLayer {
    /// Create a new rate limit layer
    pub fn new<B: Into<RateLimitBackend>>(backend: B, config: RateLimitConfig) -> Self {
        Self {
            backend: backend.into(),
            config,
            key_extractor: KeyExtractor::IpAndPath,
            trust_proxy: false,
        }
    }

    /// Set the key extractor
    pub fn with_key_extractor(mut self, extractor: KeyExtractor) -> Self {
        self.key_extractor = extractor;
        self
    }

    /// Set whether to trust proxy headers for client IP
    pub fn with_trust_proxy(mut self, trust_proxy: bool) -> Self {
        self.trust_proxy = trust_proxy;
        self
    }
}

impl<S> Layer<S> for RateLimitLayer {
    type Service = RateLimitService<S>;

    fn layer(&self, inner: S) -> Self::Service {
        RateLimitService {
            inner,
            backend: self.backend.clone(),
            config: self.config.clone(),
            key_extractor: self.key_extractor.clone(),
            trust_proxy: self.trust_proxy,
        }
    }
}

/// Rate limiting service wrapper
#[derive(Clone)]
pub struct RateLimitService<S> {
    inner: S,
    backend: RateLimitBackend,
    config: RateLimitConfig,
    key_extractor: KeyExtractor,
    trust_proxy: bool,
}

impl<S> Service<Request<Body>> for RateLimitService<S>
where
    S: Service<Request<Body>, Response = Response<Body>> + Clone + Send + 'static,
    S::Future: Send,
{
    type Response = Response<Body>;
    type Error = S::Error;
    type Future = std::pin::Pin<
        Box<dyn std::future::Future<Output = Result<Self::Response, Self::Error>> + Send>,
    >;

    fn poll_ready(
        &mut self,
        cx: &mut std::task::Context<'_>,
    ) -> std::task::Poll<Result<(), Self::Error>> {
        self.inner.poll_ready(cx)
    }

    fn call(&mut self, req: Request<Body>) -> Self::Future {
        let backend = self.backend.clone();
        let config = self.config.clone();
        let key_extractor = self.key_extractor.clone();
        let trust_proxy = self.trust_proxy;
        let mut inner = self.inner.clone();

        Box::pin(async move {
            // Build rate limit key
            let key = build_rate_limit_key(&req, key_extractor, trust_proxy);

            // Check rate limit
            let result = backend.check_and_record(&key, &config).await;

            if !result.allowed {
                // Return 429 Too Many Requests
                let error = RateLimitError {
                    code: "RATE_LIMITED",
                    message: "Too many requests. Please try again later.".to_string(),
                    retry_after: result.reset_secs,
                };

                let mut response = axum::response::IntoResponse::into_response(error);
                add_rate_limit_headers(&mut response, &result);
                return Ok(response);
            }

            // Proceed with the request
            let mut response = inner.call(req).await?;
            add_rate_limit_headers(&mut response, &result);
            Ok(response)
        })
    }
}

/// Add rate limit headers to a response
fn add_rate_limit_headers(response: &mut Response<Body>, result: &RateLimitResult) {
    use axum::http::HeaderValue;

    let headers = response.headers_mut();

    // Safe: numeric strings always produce valid header values
    if let Ok(limit) = HeaderValue::from_str(&result.limit.to_string()) {
        headers.insert("X-RateLimit-Limit", limit);
    }
    if let Ok(remaining) = HeaderValue::from_str(&result.remaining.to_string()) {
        headers.insert("X-RateLimit-Remaining", remaining);
    }
    if let Ok(reset) = HeaderValue::from_str(&result.reset_secs.to_string()) {
        headers.insert("X-RateLimit-Reset", reset);
    }
}

fn build_rate_limit_key(
    req: &Request<Body>,
    key_extractor: KeyExtractor,
    trust_proxy: bool,
) -> String {
    let ip = resolve_client_ip(req, trust_proxy);
    let path = req.uri().path();

    match key_extractor {
        KeyExtractor::IpOnly => ip.unwrap_or_else(|| {
            // SEC-007: Warn when client IP cannot be resolved.
            // Unknown IPs share a bucket which maintains rate limiting but could
            // theoretically be DoS'd if attacker can make requests without IP.
            // This is acceptable because:
            // 1. Most deployments have IP from ConnectInfo or proxy headers
            // 2. Unknown IP typically indicates proxy misconfiguration
            // 3. Grouped rate limiting is better than no rate limiting
            tracing::warn!(
                path = path,
                "Rate limit: unable to resolve client IP, using shared fallback key"
            );
            format!("unknown:{}", path)
        }),
        KeyExtractor::IpAndPath => match ip {
            Some(ip) => format!("{}:{}", ip, path),
            None => {
                // SEC-007: Warn when client IP cannot be resolved (see above)
                tracing::warn!(
                    path = path,
                    "Rate limit: unable to resolve client IP, using shared fallback key"
                );
                format!("unknown:{}", path)
            }
        },
    }
}

fn resolve_client_ip(req: &Request<Body>, trust_proxy: bool) -> Option<String> {
    if trust_proxy {
        extract_client_ip(req.headers(), true).or_else(|| {
            req.extensions()
                .get::<ConnectInfo<SocketAddr>>()
                .map(|ci| ci.0.ip().to_string())
        })
    } else {
        req.extensions()
            .get::<ConnectInfo<SocketAddr>>()
            .map(|ci| ci.0.ip().to_string())
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::middleware::rate_limit::RateLimitStore;

    #[test]
    fn test_key_extractor_clone() {
        let extractor = KeyExtractor::IpOnly;
        let cloned = extractor.clone();
        assert!(matches!(cloned, KeyExtractor::IpOnly));

        let extractor = KeyExtractor::IpAndPath;
        let cloned = extractor.clone();
        assert!(matches!(cloned, KeyExtractor::IpAndPath));
    }

    #[test]
    fn test_rate_limit_layer_creation() {
        let store = RateLimitStore::new();
        let config = RateLimitConfig {
            limit: 10,
            window_secs: 60,
        };

        let layer = RateLimitLayer::new(store.clone(), config.clone());
        let _ = layer.with_key_extractor(KeyExtractor::IpOnly);
    }

    #[test]
    fn test_build_rate_limit_key_connect_info() {
        let mut req = Request::builder()
            .uri("/login")
            .body(Body::empty())
            .unwrap();
        let addr: SocketAddr = "127.0.0.1:8080".parse().unwrap();
        req.extensions_mut().insert(ConnectInfo(addr));

        let key = build_rate_limit_key(&req, KeyExtractor::IpOnly, false);
        assert_eq!(key, "127.0.0.1");

        let key = build_rate_limit_key(&req, KeyExtractor::IpAndPath, false);
        assert_eq!(key, "127.0.0.1:/login");
    }

    #[test]
    fn test_build_rate_limit_key_trust_proxy() {
        let mut req = Request::builder()
            .uri("/login")
            .body(Body::empty())
            .unwrap();
        req.headers_mut().insert(
            "x-forwarded-for",
            axum::http::HeaderValue::from_static("192.168.1.10"),
        );

        let key = build_rate_limit_key(&req, KeyExtractor::IpOnly, true);
        assert_eq!(key, "192.168.1.10");
    }

    #[test]
    fn test_build_rate_limit_key_trust_proxy_prefers_xff() {
        let mut req = Request::builder()
            .uri("/login")
            .body(Body::empty())
            .unwrap();
        let addr: SocketAddr = "127.0.0.1:8080".parse().unwrap();
        req.extensions_mut().insert(ConnectInfo(addr));
        req.headers_mut().insert(
            "x-forwarded-for",
            axum::http::HeaderValue::from_static("203.0.113.9"),
        );

        let key = build_rate_limit_key(&req, KeyExtractor::IpOnly, true);
        assert_eq!(key, "203.0.113.9");
    }

    #[test]
    fn test_build_rate_limit_key_missing_ip_fallback() {
        let req = Request::builder()
            .uri("/login")
            .body(Body::empty())
            .unwrap();

        // When IP cannot be resolved, use shared fallback key per path
        // See SEC-007 comment in build_rate_limit_key for rationale
        let key = build_rate_limit_key(&req, KeyExtractor::IpOnly, false);
        assert_eq!(key, "unknown:/login");

        let key = build_rate_limit_key(&req, KeyExtractor::IpAndPath, false);
        assert_eq!(key, "unknown:/login");
    }
}