╭ serve_ssh.zig ────────────────────────────────────────────────╮ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ ╰───────────────────────────────────────────────────────────────╯
🬐 🬠 🬞🬂🬏 🬟 🬑 🬟 🬑 ╭aec25bfb..╮ aec25bfb.. see-em: 🬋🬋🬋 🬋🬋🬋 🬋 🬋 │files │ commits refs discuss issues new login 🬐 🬠 🬐 🬠 🬑 🬟 🬰 ╰──────────╯ (383) user
╭────╮ ╭ clone ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ╮ │http│ ssh │ │ ╰────╯ ╰ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ╯
.. embed/ event/ test/ ui/ command.zig diff3.zig event.zig lib.zig main.zig main_wasm.zig serve.zig serve_common.zig serve_http.zig ╭─────────────────────────────────╮ │serve_ssh.zig │ ╰─────────────────────────────────╯ serve_ssh_protocol.zig test.zig testnet.zig try.zig ui.zig web.zig
1 const std = @import("std"); 2 const builtin = @import("builtin"); 3 const xit = @import("xit"); 4 const rp = xit.repo; 5 const xitui = xit.xitui; 6 const StreamTerminal = xitui.stream_terminal.StreamTerminal; 7 const Grid = xitui.grid.Grid; 8 const Size = xitui.layout.Size; 9 const ui = @import("./ui.zig"); 10 const ssh = @import("./serve_ssh_protocol.zig"); 11 const evt = @import("./event.zig"); 12 const serve_common = @import("./serve_common.zig"); 13 14 // listener resource limits. the watchdog gives unauthenticated peers a hard 15 // deadline, detects idle non-interactive sessions from protocol progress, and 16 // bounds the post-CLOSE drain. each connection holds two OS threads under 17 // std.Io.Threaded (session + watchdog), so the cap is sized by thread count. 18 const max_connections: u32 = 4096; 19 const watchdog_interval = std.Io.Duration.fromSeconds(5); 20 const preauth_timeout_ticks: u32 = 6; // 30 seconds 21 const idle_timeout_ticks: u32 = 24; // 120 seconds 22 const close_drain_timeout_ticks: u32 = 2; // 5-10 seconds 23 24 var active_connections: std.atomic.Value(u32) = .init(0); 25 26 pub const SessionHandler = struct { 27 admin_repo_path: []const u8, 28 repo_root_path: []const u8, 29 wui_port: u16, // port the web UI is served on, shown in the TUI footer's url 30 clone_http_port: ?u16, 31 clone_ssh_port: ?u16, 32 err: *std.Io.Writer, 33 34 pub fn handleSession(self: *const SessionHandler, sess: *ssh.SessionCtx, request: ssh.Request) !void { 35 serve_common.logError(sess.conn.io, self.err, "ssh session: kind={s} key={s}\n", .{ @tagName(request), sess.fingerprint }); 36 switch (request) { 37 .shell => |pty_maybe| { 38 const pty = pty_maybe orelse { 39 // a shell without a pty has no useful TUI to render; in 40 // openssh client terms this is `ssh -T host`. say so and 41 // exit non-zero. 42 try sess.writeBytes("haxy ssh: this server only serves the TUI when a pty is allocated (use a normal `ssh` invocation).\r\n"); 43 try sess.exit(1); 44 return; 45 }; 46 sess.exemptFromIdleTimeout(); 47 try runTuiSession(self, sess, pty); 48 }, 49 .exec => |command| { 50 try runGitSession(self, sess, command); 51 }, 52 } 53 } 54 }; 55 56 pub fn runListener( 57 io: std.Io, 58 allocator: std.mem.Allocator, 59 host_key: *const ssh.HostKey, 60 session_handler: *const SessionHandler, 61 net_server: *std.Io.net.Server, 62 tasks: *std.Io.Group, 63 err: *std.Io.Writer, 64 ) void { 65 const Context = struct { 66 io: std.Io, 67 allocator: std.mem.Allocator, 68 host_key: *const ssh.HostKey, 69 session_handler: *const SessionHandler, 70 err: *std.Io.Writer, 71 }; 72 73 const handle = struct { 74 fn h(ctx: Context, stream: std.Io.net.Stream) void { 75 defer stream.close(ctx.io); 76 77 const prev_count = active_connections.fetchAdd(1, .monotonic); 78 defer _ = active_connections.fetchSub(1, .monotonic); 79 if (prev_count >= max_connections) { 80 serve_common.logError(ctx.io, ctx.err, "ssh: connection limit reached, dropping\n", .{}); 81 return; 82 } 83 84 var idle_state = ssh.IdleState{}; 85 var watchdog_future = std.Io.concurrent(ctx.io, watchdog, .{ ctx.io, &stream, &idle_state }) catch |spawn_err| { 86 serve_common.logError(ctx.io, ctx.err, "ssh: watchdog spawn failed: {s}\n", .{@errorName(spawn_err)}); 87 return; 88 }; 89 defer watchdog_future.cancel(ctx.io); 90 91 var recv_buf: [4096]u8 = undefined; 92 var send_buf: [4096]u8 = undefined; 93 var stream_reader = stream.reader(ctx.io, &recv_buf); 94 var stream_writer = stream.writer(ctx.io, &send_buf); 95 ssh.handleConnection( 96 ctx.io, 97 ctx.allocator, 98 &stream_reader.interface, 99 &stream_writer.interface, 100 ctx.host_key, 101 &idle_state, 102 ctx.session_handler, 103 ) catch |session_err| { 104 serve_common.logError(ctx.io, ctx.err, "ssh session failed: {s}\n", .{@errorName(session_err)}); 105 }; 106 } 107 }.h; 108 109 serve_common.runListener(io, net_server, tasks, err, "ssh", Context{ 110 .io = io, 111 .allocator = allocator, 112 .host_key = host_key, 113 .session_handler = session_handler, 114 .err = err, 115 }, handle); 116 } 117 118 // enforce a hard pre-auth deadline, an idle timeout for non-interactive 119 // sessions, and a bounded close drain. interactive sessions are exempt only 120 // from the idle timeout; the watchdog remains available to break a stalled 121 // teardown. 122 fn watchdog(io: std.Io, stream: *const std.Io.net.Stream, idle_state: *ssh.IdleState) void { 123 var last_seen: u64 = 0; 124 var preauth_ticks: u32 = 0; 125 var idle_ticks: u32 = 0; 126 var closing_ticks: u32 = 0; 127 while (true) { 128 io.sleep(watchdog_interval, .awake) catch return; // canceled — connection is done 129 130 if (idle_state.closing.load(.acquire)) { 131 closing_ticks += 1; 132 if (closing_ticks >= close_drain_timeout_ticks) { 133 stream.shutdown(io, .both) catch {}; 134 return; 135 } 136 continue; 137 } 138 139 if (!idle_state.authenticated.load(.acquire)) { 140 preauth_ticks += 1; 141 if (preauth_ticks >= preauth_timeout_ticks) { 142 stream.shutdown(io, .both) catch {}; 143 return; 144 } 145 continue; 146 } 147 148 if (idle_state.exempt.load(.monotonic)) continue; 149 const seen = idle_state.activity.load(.monotonic); 150 if (seen == last_seen) { 151 idle_ticks += 1; 152 if (idle_ticks >= idle_timeout_ticks) { 153 stream.shutdown(io, .both) catch {}; 154 return; 155 } 156 } else { 157 idle_ticks = 0; 158 } 159 last_seen = seen; 160 } 161 } 162 163 fn runTuiSession(handler: *const SessionHandler, sess: *ssh.SessionCtx, pty: ssh.PtySize) !void { 164 // runTui owns the terminal, whose deinit restores the client's screen and 165 // runs as the function unwinds — so any error it returns leaves the TUI torn 166 // down and we can surface the failure on the restored screen before exiting. 167 runTui(handler, sess, pty) catch |err| { 168 serve_common.logError(sess.conn.io, handler.err, "ssh tui session failed: {s}\n", .{@errorName(err)}); 169 var buf: [256]u8 = undefined; 170 const msg = std.fmt.bufPrint(&buf, "haxy ssh: {s}\r\n", .{@errorName(err)}) catch "haxy ssh: internal error\r\n"; 171 sess.writeBytes(msg) catch {}; 172 try sess.exit(1); 173 return; 174 }; 175 try sess.exit(0); 176 } 177 178 fn runTui(handler: *const SessionHandler, sess: *ssh.SessionCtx, pty: ssh.PtySize) !void { 179 const allocator = sess.conn.allocator; 180 const io = sess.conn.io; 181 182 // some clients (notably scripted ssh with no local controlling tty) 183 // allocate a pty without ever sending a non-zero size. fall back to a 184 // conventional 80x24 in that case so render emits something. 185 const effective_pty = ssh.PtySize{ 186 .width_cells = if (pty.width_cells == 0) 80 else pty.width_cells, 187 .height_cells = if (pty.height_cells == 0) 24 else pty.height_cells, 188 }; 189 190 // session-lifetime allocations (login, prefs); Nav owns the per-page arenas. 191 var session_arena = std.heap.ArenaAllocator.init(allocator); 192 defer session_arena.deinit(); 193 194 const Repo = rp.Repo(.xit, evt.admin_repo_opts); 195 var repo = try Repo.open(io, allocator, .{ .path = handler.admin_repo_path }); 196 defer repo.deinit(io, allocator); 197 var ui_session = try ui.Session.init(&session_arena, &repo, .{}); 198 ui_session.is_terminal = true; 199 ui_session.web_port = handler.wui_port; 200 ui_session.data.clone_http_port = handler.clone_http_port; 201 ui_session.data.clone_ssh_port = handler.clone_ssh_port; 202 // let page builders open on-disk repos (sibling "repos" dir of the admin repo) 203 ui_session.io = io; 204 ui_session.repos_dir = try std.fs.path.join(session_arena.allocator(), &.{ std.fs.path.dirname(handler.admin_repo_path) orelse ".", "repos" }); 205 206 var nav = try ui.Nav.init(allocator, &ui_session); 207 defer nav.deinit(allocator); 208 209 var session_writer_buf: [8192]u8 = undefined; 210 var session_writer = ssh.SessionWriter.init(sess, &session_writer_buf); 211 212 // the terminal's deinit writes leave-alt / show-cursor / disable-mouse and 213 // flushes, restoring the client's screen. as a function-scoped defer it runs 214 // before runTui returns — on the normal path and on any error — so the 215 // caller can write to the client afterward (and sess.exit can close cleanly). 216 var terminal_size = Size{ 217 .width = effective_pty.width_cells, 218 .height = effective_pty.height_cells, 219 }; 220 var terminal_maybe: ?StreamTerminal = try StreamTerminal.init(allocator, &session_writer.interface, terminal_size); 221 defer if (terminal_maybe) |*terminal| terminal.deinit(); 222 223 var last_size = Size{ .width = 0, .height = 0 }; 224 var last_grid = try Grid.init(allocator, last_size); 225 defer last_grid.deinit(); 226 227 // initial render — user sees the page immediately 228 try nav.root.build(allocator, .{ 229 .min_size = .{ .width = null, .height = null }, 230 .max_size = .{ .width = last_size.width, .height = last_size.height }, 231 }, nav.root.getFocus()); 232 if (terminal_maybe) |*terminal| _ = try terminal.render(&nav.root, &last_grid, &last_size); 233 234 // event loop. nextEvent blocks until something interesting arrives; 235 // for each event, rebuild the widget tree and re-render so the user 236 // sees the effect of their input on the same iteration. 237 event_loop: while (true) { 238 const event = try sess.nextEvent(); 239 if (terminal_maybe) |*terminal| { 240 switch (event) { 241 .data => |payload| { 242 defer allocator.free(payload); 243 try terminal.writeBytes(payload); 244 while (terminal.popKey()) |key| { 245 try ui.inputKey(allocator, &nav.root, key, &ui_session); 246 } 247 }, 248 .resize => |sz| { 249 terminal_size = .{ .width = sz.width_cells, .height = sz.height_cells }; 250 terminal.pushResize(terminal_size); 251 while (terminal.popKey()) |key| { 252 try ui.inputKey(allocator, &nav.root, key, &ui_session); 253 } 254 }, 255 .eof, .close => break :event_loop, 256 } 257 } else { 258 switch (event) { 259 .data => |payload| { 260 defer allocator.free(payload); 261 if (std.mem.indexOfAny(u8, payload, "\r\n") == null) continue; 262 terminal_maybe = try StreamTerminal.init(allocator, &session_writer.interface, terminal_size); 263 last_size = .{ .width = 0, .height = 0 }; 264 }, 265 .resize => |sz| { 266 terminal_size = .{ .width = sz.width_cells, .height = sz.height_cells }; 267 continue; 268 }, 269 .eof, .close => break :event_loop, 270 } 271 } 272 273 if (ui_session.host_request) |request| { 274 ui_session.host_request = null; 275 switch (request) { 276 .show_copyable_text => |copyable_text| { 277 if (terminal_maybe) |*terminal| terminal.deinit(); 278 terminal_maybe = null; 279 try session_writer.interface.print("\x1b[2J\x1b[Hcopy the following text and then press enter to go back:\r\n\r\n{s}\r\n", .{copyable_text}); 280 try session_writer.interface.flush(); 281 continue; 282 }, 283 .sync_events => {}, 284 } 285 } 286 287 try ui_session.applyAndWritePending(io, allocator, &repo); 288 289 // pick up data written by other handles so the next navigation 290 // builds its page from a current moment 291 try ui_session.reloadMoment(allocator, &repo); 292 293 // reconcile navigation: forward to a new page, or back on escape 294 try nav.sync(allocator, &ui_session); 295 296 // the quit button (on the quit tab) asks the host to tear down 297 if (ui_session.quit_requested) break :event_loop; 298 299 try nav.root.build(allocator, .{ 300 .min_size = .{ .width = null, .height = null }, 301 .max_size = .{ .width = last_size.width, .height = last_size.height }, 302 }, nav.root.getFocus()); 303 if (terminal_maybe) |*terminal| _ = try terminal.render(&nav.root, &last_grid, &last_size); 304 } 305 } 306 307 // --------------------------------------------------------------------------- 308 // git path (exec) 309 // --------------------------------------------------------------------------- 310 311 pub const GitService = enum { upload_pack, receive_pack }; 312 313 pub const ParsedGitCommand = struct { 314 service: GitService, 315 dir: []u8, 316 317 pub fn deinit(self: ParsedGitCommand, allocator: std.mem.Allocator) void { 318 allocator.free(self.dir); 319 } 320 }; 321 322 fn runGitSession(handler: *const SessionHandler, sess: *ssh.SessionCtx, command: []const u8) !void { 323 const allocator = sess.conn.allocator; 324 const io = sess.conn.io; 325 326 const parsed = parseGitCommand(allocator, command) catch return writeError(sess, "unsupported command (expected git-upload-pack or git-receive-pack)"); 327 defer parsed.deinit(allocator); 328 const repo_prefix = "/repo/"; 329 const repo_identity = if (std.mem.startsWith(u8, parsed.dir, repo_prefix)) parsed.dir[repo_prefix.len..] else parsed.dir; 330 331 const create_if_missing = parsed.service == .receive_pack; 332 const any_repo_opts: rp.AnyRepoOpts(.xit) = .{}; 333 334 // authenticate pushes: the authenticated key must be registered to the 335 // repo's owner. 336 if (create_if_missing) { 337 const owner_repo = evt.parseOwnerRepoPath(repo_identity) orelse return writeError(sess, "repo path must be <owner>/<repo>"); 338 if (builtin.mode != .Debug and !try isKeyAuthorized(io, allocator, handler.admin_repo_path, owner_repo.owner, &sess.fingerprint)) 339 return writeError(sess, "unauthorized: this SSH key is not registered to the repo owner"); 340 } 341 342 const repo_path = switch (try serve_common.resolveRepoPath(io, allocator, handler.repo_root_path, handler.admin_repo_path, repo_identity, create_if_missing)) { 343 .ok => |p| p, 344 .invalid => return writeError(sess, "repo path must be <owner>/<repo>"), 345 .not_found => return writeError(sess, "repo not found"), 346 }; 347 defer allocator.free(repo_path); 348 349 if (try serveIfExists(repo_path, sess, io, allocator, parsed.service)) { 350 try sess.exit(0); 351 return; 352 } 353 354 if (!create_if_missing) return writeError(sess, "repo not found"); 355 356 // create the on-disk repo for the just-minted event and serve the push 357 var repo = try createRepo(any_repo_opts.toRepoOpts(), io, allocator, repo_path); 358 defer repo.deinit(io, allocator); 359 try servePack(repo.self_repo_opts, &repo, sess, io, allocator, parsed.service); 360 try sess.exit(0); 361 } 362 363 // serve an existing repo at `repo_path`, or return false if none is there 364 fn serveIfExists( 365 repo_path: []const u8, 366 sess: *ssh.SessionCtx, 367 io: std.Io, 368 allocator: std.mem.Allocator, 369 service: GitService, 370 ) !bool { 371 // a bare open() creates the directory while probing for the repo, so only 372 // attempt it when the path already exists 373 std.Io.Dir.accessAbsolute(io, repo_path, .{}) catch return false; 374 375 const any_repo_opts: rp.AnyRepoOpts(.xit) = .{}; 376 var any_repo = rp.AnyRepo(.xit, any_repo_opts).open(io, allocator, .{ .path = repo_path }) catch |err| switch (err) { 377 error.RepoNotFound => return false, 378 else => |e| return e, 379 }; 380 defer any_repo.deinit(io, allocator); 381 382 switch (any_repo) { 383 inline else => |*repo| try servePack(repo.self_repo_opts, repo, sess, io, allocator, service), 384 } 385 return true; 386 } 387 388 fn createRepo( 389 comptime repo_opts: rp.RepoOpts(.xit), 390 io: std.Io, 391 allocator: std.mem.Allocator, 392 repo_path: []const u8, 393 ) !rp.Repo(.xit, repo_opts) { 394 var repo = try rp.Repo(.xit, repo_opts).init(io, allocator, .{ .path = repo_path }); 395 errdefer repo.deinit(io, allocator); 396 try repo.addConfig(io, allocator, .{ .name = "http.receivepack", .value = "true" }); 397 try repo.addConfig(io, allocator, .{ .name = "receive.denycurrentbranch", .value = "updateinstead" }); 398 return repo; 399 } 400 401 // wrap the channel I/O in std.Io.Reader/Writer adapters so the repo's pack 402 // functions can consume them like any other stream, then run the requested 403 // service 404 fn servePack( 405 comptime repo_opts: rp.RepoOpts(.xit), 406 repo: *rp.Repo(.xit, repo_opts), 407 sess: *ssh.SessionCtx, 408 io: std.Io, 409 allocator: std.mem.Allocator, 410 service: GitService, 411 ) !void { 412 var session_reader_buf: [4096]u8 = undefined; 413 var session_writer_buf: [4096]u8 = undefined; 414 var session_reader = ssh.SessionReader.init(sess, &session_reader_buf); 415 var session_writer = ssh.SessionWriter.init(sess, &session_writer_buf); 416 417 switch (service) { 418 .upload_pack => try repo.uploadPack(io, allocator, &session_reader.interface, &session_writer.interface, .{}), 419 .receive_pack => try evt.receivePackAndConsume(repo_opts, io, allocator, repo, &session_reader.interface, &session_writer.interface, .{}), 420 } 421 422 // flush whatever the pack op buffered into our writer adapter 423 session_writer.interface.flush() catch {}; 424 } 425 426 fn parseGitCommand(allocator: std.mem.Allocator, command: []const u8) !ParsedGitCommand { 427 var tokens = try std.process.Args.IteratorGeneral(.{ .single_quotes = true }).init(allocator, command); 428 defer tokens.deinit(); 429 430 const service_token = tokens.next() orelse return error.InvalidCommand; 431 const dir_token = tokens.next() orelse return error.InvalidCommand; 432 433 const service: GitService = 434 if (std.mem.eql(u8, service_token, "git-upload-pack") or std.mem.eql(u8, service_token, "upload-pack")) 435 .upload_pack 436 else if (std.mem.eql(u8, service_token, "git-receive-pack") or std.mem.eql(u8, service_token, "receive-pack")) 437 .receive_pack 438 else 439 return error.UnsupportedService; 440 441 return .{ .service = service, .dir = try allocator.dupe(u8, dir_token) }; 442 } 443 444 // true if `fingerprint` matches one of the named user's registered SSH keys 445 fn isKeyAuthorized( 446 io: std.Io, 447 allocator: std.mem.Allocator, 448 admin_repo_path: []const u8, 449 owner_name: []const u8, 450 fingerprint: *const [ssh.fingerprint_len]u8, 451 ) !bool { 452 var arena = std.heap.ArenaAllocator.init(allocator); 453 defer arena.deinit(); 454 455 const user = (try evt.User.readByName(io, allocator, admin_repo_path, &arena, owner_name)) orelse return false; 456 457 var it = std.mem.splitScalar(u8, user.event.ssh_keys, '\n'); 458 while (it.next()) |line| { 459 const fp = fingerprintOfAuthorizedKey(line) orelse continue; 460 if (std.mem.eql(u8, &fp, fingerprint)) return true; 461 } 462 return false; 463 } 464 465 // the SHA256 fingerprint of one authorized_keys line, or null if the line is 466 // blank or not a parseable "<type> <base64> [comment]" entry 467 fn fingerprintOfAuthorizedKey(line: []const u8) ?[ssh.fingerprint_len]u8 { 468 var it = std.mem.tokenizeAny(u8, line, " \t\r"); 469 _ = it.next() orelse return null; // key type 470 const blob_b64 = it.next() orelse return null; 471 472 const decoder = std.base64.standard.Decoder; 473 const blob_len = decoder.calcSizeForSlice(blob_b64) catch return null; 474 var blob_buf: [4096]u8 = undefined; 475 if (blob_len > blob_buf.len) return null; 476 decoder.decode(blob_buf[0..blob_len], blob_b64) catch return null; 477 478 return ssh.formatFingerprint(blob_buf[0..blob_len]); 479 } 480 481 fn writeError(sess: *ssh.SessionCtx, comptime msg: []const u8) !void { 482 const body = "ERR haxy ssh: " ++ msg; 483 var packet: [body.len + 4]u8 = undefined; 484 const line = try std.fmt.bufPrint(&packet, "{x:0>4}{s}", .{ packet.len, body }); 485 try sess.writeBytes(line); 486 try sess.exit(1); 487 } 488 489 test "parseGitCommand rejects malformed input" { 490 const allocator = std.testing.allocator; 491 try std.testing.expectError(error.InvalidCommand, parseGitCommand(allocator, "git-upload-pack")); 492 try std.testing.expectError(error.UnsupportedService, parseGitCommand(allocator, "ls -la")); 493 try std.testing.expectError(error.UnsupportedService, parseGitCommand(allocator, "git-fake-pack 'repo'")); 494 } 495 496 test "parseGitCommand happy paths" { 497 const allocator = std.testing.allocator; 498 499 { 500 const parsed = try parseGitCommand(allocator, "git-upload-pack 'some-repo'"); 501 defer parsed.deinit(allocator); 502 try std.testing.expectEqual(GitService.upload_pack, parsed.service); 503 try std.testing.expectEqualStrings("some-repo", parsed.dir); 504 } 505 { 506 const parsed = try parseGitCommand(allocator, "git-receive-pack 'user/proj'"); 507 defer parsed.deinit(allocator); 508 try std.testing.expectEqual(GitService.receive_pack, parsed.service); 509 try std.testing.expectEqualStrings("user/proj", parsed.dir); 510 } 511 { 512 const parsed = try parseGitCommand(allocator, "git-upload-pack repo"); 513 defer parsed.deinit(allocator); 514 try std.testing.expectEqual(GitService.upload_pack, parsed.service); 515 try std.testing.expectEqualStrings("repo", parsed.dir); 516 } 517 } 518