feature/acp-session-list-cursor
claude/github-issue-40-0au5ua
claude/linked-issue-acp-tui-u4vvpa
claude/minor-release-cut-vkugow
claude/sigit-acp-local-chat-cx6380
claude/sigit-cloud-agent-expansion-reox0a
claude/tool-permission-system
claude/zen-feynman-0u78dk
development
feature/acp-cancel-request
feature/acp-session-list-cursor
feature/acp-v1-conformance
feature/agent-tools-multiedit-glob-todos-remember
feature/cargo-workspace
feature/hooks
feature/load-local-model-explicitly
feature/sigit-agent-profile
feature/sigit-code-cloud
feature/xcode-mcp-server
fix/acp-replay-loaded-session-history
fix/acp-replay-reasoning-and-attachments
fix/dsml-doubled-bar-markers
main
release/v1.5.10
release/v1.5.6
release/v1.6.1
| 1 | //! Browser sign-in for siGit Code Cloud. |
| 2 | //! |
| 3 | //! The alternative to typing a password into a chat box. sigit is a public |
| 4 | //! OAuth client: it opens the browser at sigit.si, the person signs in and |
| 5 | //! approves there, and the authorization code comes back here. PKCE (RFC 7636) |
| 6 | //! is what proves the code belongs to this process, since a shipped CLI can |
| 7 | //! hold no client secret. |
| 8 | //! |
| 9 | //! The code comes home one of two ways: |
| 10 | //! |
| 11 | //! - **Loopback** (RFC 8252 §7.3). We bind `127.0.0.1:0`, let the OS pick the |
| 12 | //! port, and hand that URL to the server as the redirect URI. The server |
| 13 | //! registration lists `http://127.0.0.1/callback` with no port, which the |
| 14 | //! provider matches port-agnostically, so no per-run registration is needed. |
| 15 | //! Used by the editor's "Sign in" button, where there is nowhere to type. |
| 16 | //! - **Paste** (the out-of-band URN). No listener, no open port. The browser |
| 17 | //! lands on a page showing the code and the person carries it back by hand. |
| 18 | //! This is the path that survives ssh, a remote editor, or a locked-down box |
| 19 | //! where binding a port fails. |
| 20 | //! |
| 21 | //! The token that comes out is stored by [`crate::credentials`] exactly like |
| 22 | //! the one `/login` produces, so everything downstream is unchanged. |
| 23 | |
| 24 | use std::io::{Read, Write}; |
| 25 | use std::net::TcpListener; |
| 26 | use std::time::Duration; |
| 27 | |
| 28 | use base64::Engine as _; |
| 29 | use sha2::{Digest, Sha256}; |
| 30 | |
| 31 | use crate::credentials::{self, Credentials}; |
| 32 | |
| 33 | /// Client id of the siGit Code registration on sigit.si. Public clients have |
| 34 | /// no secret and their id is not one either, so it ships as a constant rather |
| 35 | /// than being configured per install. Pinned server-side by |
| 36 | /// `rake oauth:register_cli`. |
| 37 | const OAUTH_CLIENT_ID: &str = "sigit-code-cli"; |
| 38 | |
| 39 | /// `user:read` for whoami, `code:agent` for inference and the MCP tools. |
| 40 | const OAUTH_SCOPE: &str = "user:read code:agent"; |
| 41 | |
| 42 | /// Non-standard redirect URI that asks the server to display the code instead |
| 43 | /// of redirecting anywhere. |
| 44 | const OOB_REDIRECT_URI: &str = "urn:ietf:wg:oauth:2.0:oob"; |
| 45 | |
| 46 | /// How long to hold the loopback listener open waiting for the browser. The |
| 47 | /// authorization code itself expires server-side in 10 minutes; this is the |
| 48 | /// shorter local patience for someone who walked away. |
| 49 | const CALLBACK_TIMEOUT: Duration = Duration::from_secs(300); |
| 50 | |
| 51 | /// Default account host. Override with `SIGIT_API_URL` (dev: `http://localhost:8088`). |
| 52 | const DEFAULT_API_URL: &str = "https://sigit.si"; |
| 53 | |
| 54 | fn api_base() -> String { |
| 55 | std::env::var("SIGIT_API_URL") |
| 56 | .unwrap_or_else(|_| DEFAULT_API_URL.to_string()) |
| 57 | .trim_end_matches('/') |
| 58 | .to_string() |
| 59 | } |
| 60 | |
| 61 | /// An authorization in flight: the URL to send the browser to, and the secrets |
| 62 | /// needed to redeem whatever code comes back. |
| 63 | pub struct Flow { |
| 64 | authorize_url: String, |
| 65 | redirect_uri: String, |
| 66 | verifier: String, |
| 67 | state: String, |
| 68 | /// Present only for the loopback variant. |
| 69 | listener: Option<TcpListener>, |
| 70 | } |
| 71 | |
| 72 | impl Flow { |
| 73 | /// The URL the person needs to visit. Worth showing even when we opened it |
| 74 | /// ourselves: the browser we launch is not always the one they're signed |
| 75 | /// in to. |
| 76 | pub fn authorize_url(&self) -> &str { |
| 77 | &self.authorize_url |
| 78 | } |
| 79 | |
| 80 | /// True when a code will arrive on its own, false when it has to be pasted. |
| 81 | pub fn is_loopback(&self) -> bool { |
| 82 | self.listener.is_some() |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | /// Start a loopback authorization, falling back to the paste variant when no |
| 87 | /// local port can be bound. |
| 88 | pub fn begin() -> Flow { |
| 89 | match TcpListener::bind(("127.0.0.1", 0)).and_then(|listener| { |
| 90 | let port = listener.local_addr()?.port(); |
| 91 | listener.set_nonblocking(false)?; |
| 92 | Ok((listener, port)) |
| 93 | }) { |
| 94 | Ok((listener, port)) => { |
| 95 | let redirect_uri = format!("http://127.0.0.1:{port}/callback"); |
| 96 | build_flow(redirect_uri, Some(listener)) |
| 97 | } |
| 98 | Err(error) => { |
| 99 | log::warn!("no loopback port for browser sign-in ({error}); using the paste flow"); |
| 100 | build_flow(OOB_REDIRECT_URI.to_string(), None) |
| 101 | } |
| 102 | } |
| 103 | } |
| 104 | |
| 105 | /// Start a paste authorization outright, without touching the network stack. |
| 106 | pub fn begin_paste() -> Flow { |
| 107 | build_flow(OOB_REDIRECT_URI.to_string(), None) |
| 108 | } |
| 109 | |
| 110 | fn build_flow(redirect_uri: String, listener: Option<TcpListener>) -> Flow { |
| 111 | let verifier = random_token(); |
| 112 | let state = random_token(); |
| 113 | let challenge = code_challenge(&verifier); |
| 114 | |
| 115 | let authorize_url = format!( |
| 116 | "{}/oauth/authorize?response_type=code&client_id={}&redirect_uri={}&scope={}&state={}&code_challenge={}&code_challenge_method=S256", |
| 117 | api_base(), |
| 118 | percent_encode(OAUTH_CLIENT_ID), |
| 119 | percent_encode(&redirect_uri), |
| 120 | percent_encode(OAUTH_SCOPE), |
| 121 | percent_encode(&state), |
| 122 | percent_encode(&challenge), |
| 123 | ); |
| 124 | |
| 125 | Flow { |
| 126 | authorize_url, |
| 127 | redirect_uri, |
| 128 | verifier, |
| 129 | state, |
| 130 | listener, |
| 131 | } |
| 132 | } |
| 133 | |
| 134 | /// Hand the authorize URL to the platform's browser. Best-effort: a headless |
| 135 | /// box has nothing to open, which is not a reason to abandon the flow, since |
| 136 | /// the URL can still be carried to a browser elsewhere. |
| 137 | pub fn open_browser(url: &str) -> bool { |
| 138 | #[cfg(target_os = "macos")] |
| 139 | let mut command = { |
| 140 | let mut c = std::process::Command::new("open"); |
| 141 | c.arg(url); |
| 142 | c |
| 143 | }; |
| 144 | #[cfg(target_os = "windows")] |
| 145 | let mut command = { |
| 146 | // `start` is a cmd builtin, and its first quoted argument is taken as |
| 147 | // the window title, hence the empty one. |
| 148 | let mut c = std::process::Command::new("cmd"); |
| 149 | c.args(["/C", "start", "", url]); |
| 150 | c |
| 151 | }; |
| 152 | #[cfg(all(unix, not(target_os = "macos")))] |
| 153 | let mut command = { |
| 154 | let mut c = std::process::Command::new("xdg-open"); |
| 155 | c.arg(url); |
| 156 | c |
| 157 | }; |
| 158 | |
| 159 | command |
| 160 | .stdout(std::process::Stdio::null()) |
| 161 | .stderr(std::process::Stdio::null()) |
| 162 | .status() |
| 163 | .map(|status| status.success()) |
| 164 | .unwrap_or(false) |
| 165 | } |
| 166 | |
| 167 | /// Block on the loopback listener until the browser redirects back, then |
| 168 | /// redeem the code and store the session. Returns the signed-in email. |
| 169 | /// |
| 170 | /// Runs the socket work on a blocking thread: the wait is minutes long and |
| 171 | /// must not sit on an async worker. |
| 172 | pub async fn complete_loopback(flow: Flow) -> Result<String, String> { |
| 173 | let Flow { |
| 174 | redirect_uri, |
| 175 | verifier, |
| 176 | state, |
| 177 | listener, |
| 178 | .. |
| 179 | } = flow; |
| 180 | let listener = listener.ok_or_else(|| "this sign-in has no local listener".to_string())?; |
| 181 | |
| 182 | let expected_state = state.clone(); |
| 183 | let code = tokio::task::spawn_blocking(move || wait_for_code(listener, &expected_state)) |
| 184 | .await |
| 185 | .map_err(|error| format!("sign-in was interrupted: {error}"))??; |
| 186 | |
| 187 | exchange(&code, &verifier, &redirect_uri).await |
| 188 | } |
| 189 | |
| 190 | /// Redeem a code the person pasted in. Returns the signed-in email. |
| 191 | pub async fn complete_paste(flow: &Flow, code: &str) -> Result<String, String> { |
| 192 | let code = code.trim(); |
| 193 | if code.is_empty() { |
| 194 | return Err("no code was entered".to_string()); |
| 195 | } |
| 196 | exchange(code, &flow.verifier, &flow.redirect_uri).await |
| 197 | } |
| 198 | |
| 199 | /// Accept connections until one carries our callback. Anything else on the |
| 200 | /// port (a browser probe, a stray scan) is answered and ignored rather than |
| 201 | /// ending the wait. |
| 202 | fn wait_for_code(listener: TcpListener, expected_state: &str) -> Result<String, String> { |
| 203 | let deadline = std::time::Instant::now() + CALLBACK_TIMEOUT; |
| 204 | listener |
| 205 | .set_nonblocking(true) |
| 206 | .map_err(|error| format!("could not watch for the browser: {error}"))?; |
| 207 | |
| 208 | 'connections: loop { |
| 209 | if std::time::Instant::now() >= deadline { |
| 210 | return Err("timed out waiting for the browser".to_string()); |
| 211 | } |
| 212 | |
| 213 | let mut stream = match listener.accept() { |
| 214 | Ok((stream, _)) => stream, |
| 215 | Err(error) if error.kind() == std::io::ErrorKind::WouldBlock => { |
| 216 | std::thread::sleep(Duration::from_millis(100)); |
| 217 | continue; |
| 218 | } |
| 219 | Err(error) => return Err(format!("could not accept the browser: {error}")), |
| 220 | }; |
| 221 | if std::time::Instant::now() >= deadline { |
| 222 | return Err("timed out waiting for the browser".to_string()); |
| 223 | } |
| 224 | stream |
| 225 | .set_nonblocking(false) |
| 226 | .map_err(|error| format!("could not read the browser callback: {error}"))?; |
| 227 | let remaining = deadline.saturating_duration_since(std::time::Instant::now()); |
| 228 | stream |
| 229 | .set_read_timeout(Some(remaining.min(Duration::from_secs(5)))) |
| 230 | .map_err(|error| format!("could not read the browser callback: {error}"))?; |
| 231 | |
| 232 | // Read through the end of the request line; a TCP read may return a |
| 233 | // partial line when the request spans multiple packets. |
| 234 | let mut buffer = [0_u8; 4096]; |
| 235 | let mut read = 0; |
| 236 | while read < buffer.len() { |
| 237 | match stream.read(&mut buffer[read..]) { |
| 238 | Ok(0) => break, |
| 239 | Ok(count) => { |
| 240 | read += count; |
| 241 | if buffer[..read].windows(2).any(|window| window == b"\r\n") { |
| 242 | break; |
| 243 | } |
| 244 | } |
| 245 | Err(error) => { |
| 246 | respond(&mut stream, "Could not read the sign-in callback."); |
| 247 | log::debug!("could not read browser callback: {error}"); |
| 248 | continue 'connections; |
| 249 | } |
| 250 | } |
| 251 | } |
| 252 | let request = String::from_utf8_lossy(&buffer[..read]); |
| 253 | let Some(target) = request |
| 254 | .lines() |
| 255 | .next() |
| 256 | .and_then(|line| line.split_whitespace().nth(1)) |
| 257 | else { |
| 258 | respond(&mut stream, "Bad request."); |
| 259 | continue; |
| 260 | }; |
| 261 | |
| 262 | let query = target.split_once('?').map(|(_, query)| query).unwrap_or(""); |
| 263 | let mut code = None; |
| 264 | let mut state = None; |
| 265 | let mut error = None; |
| 266 | for (key, value) in parse_query(query) { |
| 267 | match key.as_str() { |
| 268 | "code" => code = Some(value), |
| 269 | "state" => state = Some(value), |
| 270 | "error" => error = Some(value), |
| 271 | _ => {} |
| 272 | } |
| 273 | } |
| 274 | |
| 275 | if let Some(error) = error { |
| 276 | respond( |
| 277 | &mut stream, |
| 278 | "Sign-in was cancelled. You can close this tab.", |
| 279 | ); |
| 280 | return Err(format!("sign-in was declined ({error})")); |
| 281 | } |
| 282 | |
| 283 | let Some(code) = code else { |
| 284 | respond(&mut stream, "Nothing to do here."); |
| 285 | continue; |
| 286 | }; |
| 287 | |
| 288 | // The state proves this callback belongs to the flow we started, not |
| 289 | // to a link someone else sent to this browser. |
| 290 | if state.as_deref() != Some(expected_state) { |
| 291 | respond(&mut stream, "That sign-in did not come from siGit Code."); |
| 292 | return Err("the sign-in response did not match this request".to_string()); |
| 293 | } |
| 294 | |
| 295 | respond( |
| 296 | &mut stream, |
| 297 | "Signed in to siGit Code. You can close this tab.", |
| 298 | ); |
| 299 | return Ok(code); |
| 300 | } |
| 301 | } |
| 302 | |
| 303 | fn respond(stream: &mut std::net::TcpStream, message: &str) { |
| 304 | let body = format!( |
| 305 | "<!doctype html><meta charset=\"utf-8\"><title>siGit Code</title>\ |
| 306 | <body style=\"font:16px system-ui;display:grid;place-items:center;height:90vh\">\ |
| 307 | <p>{message}</p></body>" |
| 308 | ); |
| 309 | let response = format!( |
| 310 | "HTTP/1.1 200 OK\r\nContent-Type: text/html; charset=utf-8\r\nContent-Length: {}\r\nConnection: close\r\n\r\n{}", |
| 311 | body.len(), |
| 312 | body |
| 313 | ); |
| 314 | let _ = stream.write_all(response.as_bytes()); |
| 315 | let _ = stream.flush(); |
| 316 | } |
| 317 | |
| 318 | /// Trade the authorization code for an access token and store it. |
| 319 | async fn exchange(code: &str, verifier: &str, redirect_uri: &str) -> Result<String, String> { |
| 320 | let url = format!("{}/oauth/token", api_base()); |
| 321 | let response = reqwest::Client::new() |
| 322 | .post(&url) |
| 323 | .form(&[ |
| 324 | ("grant_type", "authorization_code"), |
| 325 | ("client_id", OAUTH_CLIENT_ID), |
| 326 | ("redirect_uri", redirect_uri), |
| 327 | ("code", code), |
| 328 | ("code_verifier", verifier), |
| 329 | ]) |
| 330 | .send() |
| 331 | .await |
| 332 | .map_err(|error| format!("could not reach siGit Code Cloud: {error}"))?; |
| 333 | |
| 334 | let status = response.status(); |
| 335 | let body: serde_json::Value = response |
| 336 | .json() |
| 337 | .await |
| 338 | .map_err(|error| format!("unexpected response from siGit Code Cloud: {error}"))?; |
| 339 | |
| 340 | if !status.is_success() { |
| 341 | // OAuth error bodies are `{"error":…,"error_description":…}`. |
| 342 | let detail = body |
| 343 | .get("error_description") |
| 344 | .or_else(|| body.get("error")) |
| 345 | .and_then(|value| value.as_str()) |
| 346 | .unwrap_or("the code could not be exchanged"); |
| 347 | return Err(format!("sign-in failed: {detail}")); |
| 348 | } |
| 349 | |
| 350 | let token = body |
| 351 | .get("access_token") |
| 352 | .and_then(|value| value.as_str()) |
| 353 | .filter(|token| !token.trim().is_empty()) |
| 354 | .ok_or_else(|| "siGit Code Cloud returned no access token".to_string())?; |
| 355 | |
| 356 | // The token is the thing worth keeping, and the email is only there to |
| 357 | // label it. Store once so a profile lookup failure does not leave partial |
| 358 | // state on disk. |
| 359 | let email = fetch_email(token).await; |
| 360 | credentials::store(&Credentials { |
| 361 | access_token: token.to_string(), |
| 362 | email: email.clone(), |
| 363 | })?; |
| 364 | |
| 365 | Ok(email.unwrap_or_else(|| "(unknown)".to_string())) |
| 366 | } |
| 367 | |
| 368 | /// Read the account email for display. OAuth tokens are served by |
| 369 | /// `/api/v1/user`, not the deprecated `/api/v1/me`. |
| 370 | async fn fetch_email(token: &str) -> Option<String> { |
| 371 | let url = format!("{}/api/v1/user", api_base()); |
| 372 | let response = reqwest::Client::new() |
| 373 | .get(&url) |
| 374 | .bearer_auth(token) |
| 375 | .send() |
| 376 | .await |
| 377 | .ok()?; |
| 378 | if !response.status().is_success() { |
| 379 | return None; |
| 380 | } |
| 381 | response |
| 382 | .json::<serde_json::Value>() |
| 383 | .await |
| 384 | .ok()? |
| 385 | .get("email")? |
| 386 | .as_str() |
| 387 | .map(str::to_string) |
| 388 | } |
| 389 | |
| 390 | /// 32 random bytes, base64url without padding: a PKCE verifier and a state |
| 391 | /// value both want an unguessable ASCII string of exactly this shape. |
| 392 | fn random_token() -> String { |
| 393 | let mut bytes = [0_u8; 32]; |
| 394 | rand::fill(&mut bytes); |
| 395 | base64::engine::general_purpose::URL_SAFE_NO_PAD.encode(bytes) |
| 396 | } |
| 397 | |
| 398 | /// S256: base64url(sha256(verifier)), unpadded. |
| 399 | fn code_challenge(verifier: &str) -> String { |
| 400 | let digest = Sha256::digest(verifier.as_bytes()); |
| 401 | base64::engine::general_purpose::URL_SAFE_NO_PAD.encode(digest) |
| 402 | } |
| 403 | |
| 404 | /// Percent-encode a query-string value. Everything outside the unreserved set |
| 405 | /// is escaped, which is stricter than necessary and never wrong. |
| 406 | fn percent_encode(value: &str) -> String { |
| 407 | let mut out = String::with_capacity(value.len()); |
| 408 | for byte in value.bytes() { |
| 409 | match byte { |
| 410 | b'A'..=b'Z' | b'a'..=b'z' | b'0'..=b'9' | b'-' | b'_' | b'.' | b'~' => { |
| 411 | out.push(byte as char) |
| 412 | } |
| 413 | _ => out.push_str(&format!("%{byte:02X}")), |
| 414 | } |
| 415 | } |
| 416 | out |
| 417 | } |
| 418 | |
| 419 | /// Split a query string into decoded key/value pairs. |
| 420 | fn parse_query(query: &str) -> Vec<(String, String)> { |
| 421 | query |
| 422 | .split('&') |
| 423 | .filter(|pair| !pair.is_empty()) |
| 424 | .map(|pair| { |
| 425 | let (key, value) = pair.split_once('=').unwrap_or((pair, "")); |
| 426 | (percent_decode(key), percent_decode(value)) |
| 427 | }) |
| 428 | .collect() |
| 429 | } |
| 430 | |
| 431 | fn percent_decode(value: &str) -> String { |
| 432 | let bytes = value.as_bytes(); |
| 433 | let mut out = Vec::with_capacity(bytes.len()); |
| 434 | let mut index = 0; |
| 435 | while index < bytes.len() { |
| 436 | match bytes[index] { |
| 437 | b'%' if index + 3 <= bytes.len() => { |
| 438 | let hex = std::str::from_utf8(&bytes[index + 1..index + 3]).unwrap_or(""); |
| 439 | match u8::from_str_radix(hex, 16) { |
| 440 | Ok(byte) => { |
| 441 | out.push(byte); |
| 442 | index += 3; |
| 443 | } |
| 444 | Err(_) => { |
| 445 | out.push(bytes[index]); |
| 446 | index += 1; |
| 447 | } |
| 448 | } |
| 449 | } |
| 450 | b'+' => { |
| 451 | out.push(b' '); |
| 452 | index += 1; |
| 453 | } |
| 454 | byte => { |
| 455 | out.push(byte); |
| 456 | index += 1; |
| 457 | } |
| 458 | } |
| 459 | } |
| 460 | String::from_utf8_lossy(&out).into_owned() |
| 461 | } |
| 462 | |
| 463 | #[cfg(test)] |
| 464 | mod tests { |
| 465 | use super::*; |
| 466 | |
| 467 | #[test] |
| 468 | fn code_challenge_matches_rfc_7636_example() { |
| 469 | // RFC 7636 Appendix B. |
| 470 | let verifier = "dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk"; |
| 471 | assert_eq!( |
| 472 | code_challenge(verifier), |
| 473 | "E9Melhoa2OwvFrEMTJguCHaoeK1t8URWbuGJSstw-cM" |
| 474 | ); |
| 475 | } |
| 476 | |
| 477 | #[test] |
| 478 | fn authorize_url_carries_pkce_and_the_bound_port() { |
| 479 | let flow = begin(); |
| 480 | assert!(flow.is_loopback(), "a loopback port should be available"); |
| 481 | assert!(flow.authorize_url().contains("code_challenge_method=S256")); |
| 482 | assert!(flow.authorize_url().contains("response_type=code")); |
| 483 | // The redirect URI is encoded, so look for the escaped form. |
| 484 | assert!( |
| 485 | flow.authorize_url().contains("http%3A%2F%2F127.0.0.1%3A"), |
| 486 | "authorize url should carry the loopback redirect: {}", |
| 487 | flow.authorize_url() |
| 488 | ); |
| 489 | } |
| 490 | |
| 491 | #[test] |
| 492 | fn paste_flow_asks_the_server_to_display_the_code() { |
| 493 | let flow = begin_paste(); |
| 494 | assert!(!flow.is_loopback()); |
| 495 | assert!( |
| 496 | flow.authorize_url() |
| 497 | .contains("urn%3Aietf%3Awg%3Aoauth%3A2.0%3Aoob") |
| 498 | ); |
| 499 | } |
| 500 | |
| 501 | #[test] |
| 502 | fn verifier_and_state_differ_between_flows() { |
| 503 | let first = begin_paste(); |
| 504 | let second = begin_paste(); |
| 505 | assert_ne!(first.verifier, second.verifier); |
| 506 | assert_ne!(first.state, second.state); |
| 507 | assert_eq!(first.verifier.len(), 43, "32 bytes as unpadded base64url"); |
| 508 | } |
| 509 | |
| 510 | #[test] |
| 511 | fn query_parsing_decodes_escapes() { |
| 512 | let pairs = parse_query("code=abc%2Fdef&state=x+y"); |
| 513 | assert_eq!(pairs[0], ("code".to_string(), "abc/def".to_string())); |
| 514 | assert_eq!(pairs[1], ("state".to_string(), "x y".to_string())); |
| 515 | } |
| 516 | |
| 517 | #[test] |
| 518 | fn percent_decode_handles_escape_at_end() { |
| 519 | assert_eq!(percent_decode("code%2F"), "code/"); |
| 520 | } |
| 521 | } |