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fakecloud_core/
dispatch.rs

1use axum::body::Body;
2use axum::extract::{ConnectInfo, Extension, Query};
3use axum::http::{Request, StatusCode};
4use axum::response::Response;
5use bytes::Bytes;
6use std::collections::HashMap;
7use std::net::SocketAddr;
8use std::sync::Arc;
9
10use crate::auth::{
11    is_root_bypass, ConditionContext, CredentialResolver, IamMode, IamPolicyEvaluator, Principal,
12    PrincipalType, ResourcePolicyProvider,
13};
14use crate::protocol::{self, AwsProtocol};
15use crate::registry::ServiceRegistry;
16use crate::service::{AwsRequest, ResponseBody};
17
18/// The main dispatch handler. All HTTP requests come through here.
19pub async fn dispatch(
20    ConnectInfo(remote_addr): ConnectInfo<SocketAddr>,
21    Extension(registry): Extension<Arc<ServiceRegistry>>,
22    Extension(config): Extension<Arc<DispatchConfig>>,
23    Query(query_params): Query<HashMap<String, String>>,
24    request: Request<Body>,
25) -> Response<Body> {
26    let remote_addr = Some(remote_addr);
27    let request_id = uuid::Uuid::new_v4().to_string();
28
29    let (parts, body) = request.into_parts();
30
31    // Streaming opt-in: if the route is a known large-body S3 / ECR
32    // upload, we skip the buffered `to_bytes` step entirely and hand
33    // the raw body to the service handler. The handler spills it to
34    // disk on the fly. Header-only detection covers every streaming
35    // candidate (none of them rely on form-body sniffing).
36    let stream_route = streaming_route(
37        &parts.method,
38        parts.uri.path(),
39        &parts.headers,
40        &query_params,
41    );
42    let header_only = protocol::detect_service_headers_only(&parts.headers, &query_params);
43    let stream_dispatch = match (&stream_route, &header_only) {
44        // Header-only detection agrees with the URL match — covers S3
45        // PUT object (SigV4 service=s3 in Authorization).
46        (Some(sr), Some(detected)) if sr.0 == detected.service => Some(detected.clone()),
47        // ECR OCI v2 blob upload has no AWS auth header; the path
48        // alone (`/v2/.../blobs/uploads/...`) tells us the route is
49        // ECR. Synthesize a DetectedRequest so dispatch picks the
50        // streaming path. Same special-case the buffered branch
51        // applies on detect_service None (see below).
52        (Some((service, _)), None) if *service == "ecr" => Some(protocol::DetectedRequest {
53            service: "ecr".to_string(),
54            action: String::new(),
55            protocol: AwsProtocol::Rest,
56        }),
57        _ => None,
58    };
59
60    let (body_bytes, body_stream) = if stream_dispatch.is_some() {
61        (Bytes::new(), Some(body))
62    } else {
63        // Buffered path: materialize the body into memory under the
64        // configured cap. `FAKECLOUD_MAX_REQUEST_BODY_BYTES` (default
65        // 1 GiB) caps non-streaming requests; streaming routes have no
66        // cap because nothing materializes the entire body in RAM.
67        let max_body_bytes = max_request_body_bytes();
68        match axum::body::to_bytes(body, max_body_bytes).await {
69            Ok(b) => (b, None),
70            Err(_) => {
71                return build_error_response(
72                    StatusCode::PAYLOAD_TOO_LARGE,
73                    "RequestEntityTooLarge",
74                    "Request body too large",
75                    &request_id,
76                    AwsProtocol::Query,
77                );
78            }
79        }
80    };
81
82    // Detect service and action
83    let detected = if let Some(d) = stream_dispatch {
84        d
85    } else {
86        match protocol::detect_service(&parts.headers, &query_params, &body_bytes) {
87            Some(d) => d,
88            None => {
89                // A request carrying X-Amz-Target is unambiguously an awsJson
90                // call whose operation we couldn't map to a known service. AWS
91                // answers these with UnknownOperationException; routing them to
92                // the apigateway catch-all below would 404 with a misleading
93                // "Stage not found" instead.
94                if let Some(target) = parts
95                    .headers
96                    .get("x-amz-target")
97                    .and_then(|v| v.to_str().ok())
98                {
99                    return build_error_response(
100                        StatusCode::BAD_REQUEST,
101                        "UnknownOperationException",
102                        &format!("The operation {target} is not recognized."),
103                        &request_id,
104                        AwsProtocol::Json,
105                    );
106                }
107                // OPTIONS requests (CORS preflight) don't carry Authorization headers.
108                // Route them to S3 since S3 is the only REST service that handles CORS.
109                // Note: API Gateway CORS preflight is not fully supported in this emulator
110                // because we can't distinguish between S3 and API Gateway OPTIONS requests
111                // without additional context (in real AWS, they have different domains).
112                if parts.method == http::Method::OPTIONS {
113                    protocol::DetectedRequest {
114                        service: "s3".to_string(),
115                        action: String::new(),
116                        protocol: AwsProtocol::Rest,
117                    }
118                } else if parts.uri.path() == "/v2" || parts.uri.path().starts_with("/v2/") {
119                    // OCI Distribution v2 protocol. Docker CLI / OCI clients
120                    // use Basic auth (not SigV4) and GET /v2/ with no body,
121                    // so this must be matched before the apigateway fallback.
122                    protocol::DetectedRequest {
123                        service: "ecr".to_string(),
124                        action: String::new(),
125                        protocol: AwsProtocol::Rest,
126                    }
127                } else if let Some(bucket) = anonymous_s3_bucket(&parts.uri, &config) {
128                    // Unsigned request whose first path segment names an
129                    // existing S3 bucket: an anonymous path-style S3 access
130                    // (e.g. serving a public-read object to a browser). Without
131                    // this it would fall through to the apigateway catch-all
132                    // below and 404 with "Stage not found" (#1707). Authorization
133                    // for the anonymous caller still runs in the IAM block.
134                    tracing::debug!(bucket = %bucket, "routing unsigned request to S3 (existing bucket)");
135                    protocol::DetectedRequest {
136                        service: "s3".to_string(),
137                        action: String::new(),
138                        protocol: AwsProtocol::Rest,
139                    }
140                } else if !parts.uri.path().starts_with("/_") {
141                    // Requests without AWS auth that don't match any service might be
142                    // API Gateway execute API calls (plain HTTP without signatures).
143                    // Route them to apigateway service which will validate if a matching
144                    // API/stage exists. Skip special FakeCloud endpoints (/_*).
145                    protocol::DetectedRequest {
146                        service: "apigateway".to_string(),
147                        action: String::new(),
148                        protocol: AwsProtocol::RestJson,
149                    }
150                } else {
151                    return build_error_response(
152                        StatusCode::BAD_REQUEST,
153                        "MissingAction",
154                        "Could not determine target service or action from request",
155                        &request_id,
156                        AwsProtocol::Query,
157                    );
158                }
159            }
160        }
161    };
162
163    // Bedrock-agent and bedrock-runtime both send `bedrock` in the SigV4
164    // credential scope, but bedrock-agent has its own service handler.
165    // Disambiguate based on the request path.
166    let detected = if detected.service == "bedrock" {
167        let first_seg = parts.uri.path().split('/').nth(1);
168        if matches!(
169            first_seg,
170            Some(
171                "agents"
172                    | "knowledgebases"
173                    | "flows"
174                    | "prompts"
175                    | "tags"
176                    | "retrieveAndGenerate"
177                    | "retrieveAndGenerateStream"
178                    | "optimize-prompt"
179                    | "sessions"
180                    | "invocations"
181                    | "generate-query"
182                    | "rerank"
183            )
184        ) {
185            // Further disambiguate runtime vs control plane for agents/flows paths
186            let segs: Vec<&str> = parts.uri.path().split('/').collect();
187            let is_runtime = matches!(
188                segs.as_slice(),
189                ["", "agents", _, "agentAliases", _, ..]  // InvokeAgent
190                    | ["", "flows", _, "aliases", _]   // InvokeFlow
191                    | ["", "knowledgebases", _, "retrieve"] // Retrieve
192                    | ["", "retrieveAndGenerate"]
193                    | ["", "retrieveAndGenerateStream"]
194                    | ["", "optimize-prompt"]
195                    | ["", "sessions", ..]
196                    | ["", "invocations", ..]
197                    | ["", "generate-query"]
198                    | ["", "rerank"]
199            );
200            if is_runtime {
201                protocol::DetectedRequest {
202                    service: "bedrock-agent-runtime".to_string(),
203                    ..detected
204                }
205            } else {
206                protocol::DetectedRequest {
207                    service: "bedrock-agent".to_string(),
208                    ..detected
209                }
210            }
211        } else {
212            detected
213        }
214    } else {
215        detected
216    };
217
218    // Amazon DocumentDB shares RDS's Query wire protocol, `rds` SigV4
219    // signing scope, and `rds.<region>.amazonaws.com` endpoint, so a real
220    // `aws-sdk-docdb` request is indistinguishable from `aws-sdk-rds` by
221    // signing name or host alone. The DocumentDB SDK does stamp an
222    // `api/docdb` token into its `user-agent`; use it to route the request
223    // to the dedicated `docdb` handler. (The conformance probe signs the
224    // `docdb` scope directly, so it never reaches this branch.) Requests
225    // without the token stay on `rds`.
226    let detected = if detected.service == "rds" && user_agent_indicates_docdb(&parts.headers) {
227        protocol::DetectedRequest {
228            service: "docdb".to_string(),
229            ..detected
230        }
231    } else {
232        detected
233    };
234
235    // Amazon Neptune shares RDS's Query wire protocol, `rds` SigV4 signing
236    // scope, and `rds.<region>.amazonaws.com` endpoint, so a real
237    // `aws-sdk-neptune` request is indistinguishable from `aws-sdk-rds` by
238    // signing name or host alone. The Neptune SDK does stamp an
239    // `api/neptune` token into its `user-agent`; use it to route the request
240    // to the dedicated `neptune` handler. (The conformance probe signs the
241    // `neptune` scope directly, so it never reaches this branch.) Requests
242    // without the token stay on `rds`.
243    let detected = if detected.service == "rds" && user_agent_indicates_neptune(&parts.headers) {
244        protocol::DetectedRequest {
245            service: "neptune".to_string(),
246            ..detected
247        }
248    } else {
249        detected
250    };
251
252    // Look up service
253    let service = match registry.get(&detected.service) {
254        Some(s) => s,
255        None => {
256            return build_error_response(
257                detected.protocol.error_status(),
258                "UnknownService",
259                &format!("Service '{}' is not available", detected.service),
260                &request_id,
261                detected.protocol,
262            );
263        }
264    };
265
266    // Extract region and access key from auth header (or presigned query).
267    let auth_header = parts
268        .headers
269        .get("authorization")
270        .and_then(|v| v.to_str().ok())
271        .unwrap_or("");
272    let header_info = fakecloud_aws::sigv4::parse_sigv4(auth_header);
273    let presigned_info = if header_info.is_none() {
274        // Presigned URL: credentials live in the query string.
275        fakecloud_aws::sigv4::parse_sigv4_presigned(&query_params).map(|p| p.as_info())
276    } else {
277        None
278    };
279    let sigv4_info = header_info.or(presigned_info);
280    // SigV2 presigned URLs (`AWSAccessKeyId` + `Signature` + `Expires` query
281    // parameters) carry the access key outside the SigV4 grammar, so the SigV4
282    // parsers above return None. Recover the key here so a SigV2-presigned
283    // request is attributed to its caller instead of being treated as
284    // anonymous (which would deny it under the object read auth gate).
285    let access_key_id = sigv4_info
286        .as_ref()
287        .map(|info| info.access_key.clone())
288        .or_else(|| sigv2_presigned_access_key(&query_params));
289
290    // Host-header routing hint: LocalStack-shaped
291    // `<svc>.<region>.localhost.localstack.cloud[:port]`, real-AWS
292    // `<svc>.<region>.amazonaws.com`, and every S3 virtual-hosted variant
293    // of both. Secondary region source and carries the bucket for
294    // virtual-hosted S3 path rewrite.
295    let host_info = protocol::parse_routing_host_from_headers(&parts.headers);
296
297    let region = sigv4_info
298        .map(|info| info.region)
299        .or_else(|| host_info.as_ref().map(|h| h.region.clone()))
300        .or_else(|| extract_region_from_user_agent(&parts.headers))
301        .unwrap_or_else(|| config.region.clone());
302
303    // Resolve the caller's principal up front so both SigV4 verification
304    // (which needs the secret) and the service handler (which needs the
305    // identity for GetCallerIdentity and IAM enforcement) share a single
306    // lookup. The root-bypass AKID skips resolution entirely — `test`
307    // credentials have no backing identity and must always pass.
308    let caller_akid = access_key_id.as_deref().unwrap_or("");
309    let resolved = if !caller_akid.is_empty() && !is_root_bypass(caller_akid) {
310        config
311            .credential_resolver
312            .as_ref()
313            .and_then(|r| r.resolve(caller_akid))
314    } else {
315        None
316    };
317    let caller_principal = resolved.as_ref().map(|r| r.principal.clone());
318    let caller_session_policies = resolved
319        .as_ref()
320        .map(|r| r.session_policies.clone())
321        .unwrap_or_default();
322
323    // Opt-in SigV4 cryptographic verification. Runs before the service
324    // handler so a failing signature never reaches business logic. The
325    // reserved `test*` root identity short-circuits verification to keep
326    // local-dev workflows frictionless.
327    //
328    // A fully anonymous request — no `Authorization` header AND no presigned
329    // credential (SigV4 `X-Amz-Credential` or SigV2 `AWSAccessKeyId`) — carries
330    // no signature to verify, so it must NOT be hard-403'd here even under
331    // `--verify-sigv4`. AWS treats an unsigned request as the anonymous
332    // principal and lets a resource policy / public-read ACL authorize it
333    // (e.g. a public S3 object GET). Let it fall through to the
334    // anonymous-authorization path below, which allows a public resource and
335    // otherwise denies. A request that DID present a credential but failed to
336    // parse is NOT anonymous (`Authorization` non-empty or a presign query
337    // present) and still returns the malformed-signature error below.
338    let is_fully_anonymous = auth_header.is_empty()
339        && !query_params.contains_key("X-Amz-Credential")
340        && sigv2_presigned_access_key(&query_params).is_none();
341    if config.verify_sigv4
342        && !is_fully_anonymous
343        && !is_root_bypass(caller_akid)
344        && config.credential_resolver.is_some()
345    {
346        let amz_date = parts
347            .headers
348            .get("x-amz-date")
349            .and_then(|v| v.to_str().ok());
350        let parsed = fakecloud_aws::sigv4::parse_sigv4_header(auth_header, amz_date)
351            .or_else(|| fakecloud_aws::sigv4::parse_sigv4_presigned(&query_params));
352        let parsed = match parsed {
353            Some(p) => p,
354            None => {
355                return build_error_response(
356                    StatusCode::FORBIDDEN,
357                    "IncompleteSignature",
358                    "Request is missing or has a malformed AWS Signature",
359                    &request_id,
360                    detected.protocol,
361                );
362            }
363        };
364        let resolved_for_verify = match resolved.as_ref() {
365            Some(r) => r,
366            None => {
367                return build_error_response(
368                    StatusCode::FORBIDDEN,
369                    "InvalidClientTokenId",
370                    "The security token included in the request is invalid",
371                    &request_id,
372                    detected.protocol,
373                );
374            }
375        };
376        let headers_vec = fakecloud_aws::sigv4::headers_from_http(&parts.headers);
377        let raw_query_for_verify = parts.uri.query().unwrap_or("").to_string();
378        let verify_req = fakecloud_aws::sigv4::VerifyRequest {
379            method: parts.method.as_str(),
380            path: parts.uri.path(),
381            query: &raw_query_for_verify,
382            headers: &headers_vec,
383            body: &body_bytes,
384        };
385        match fakecloud_aws::sigv4::verify(
386            &parsed,
387            &verify_req,
388            &resolved_for_verify.secret_access_key,
389            chrono::Utc::now(),
390        ) {
391            Ok(()) => {
392                // Bind the buffered request body to the signed
393                // `x-amz-content-sha256`. The sigv4 canonical builder uses that
394                // header value verbatim (it is a signed header) and deliberately
395                // does NOT re-hash the body: for streaming / aws-chunked routes
396                // `body_bytes` is empty at that layer, so re-hashing there would
397                // reject legitimate signed requests (see the
398                // `feedback_sigv4_body_hash_wrong_layer` caveat). S3 rebinds the
399                // body hash in its own write path (`XAmzContentSHA256Mismatch`);
400                // every other service is bound HERE, where the full buffered body
401                // is available. Only a genuine 64-char lowercase-hex digest is
402                // checked — `UNSIGNED-PAYLOAD`, `STREAMING-*`, and presigned
403                // (UNSIGNED-PAYLOAD) requests are skipped, so correct clients are
404                // unaffected. A mismatch means the body was altered after signing;
405                // AWS would then compute a different canonical request, so return
406                // `SignatureDoesNotMatch`.
407                if !parsed.is_presigned && detected.service != "s3" {
408                    if let Some(signed_hash) = parts
409                        .headers
410                        .get("x-amz-content-sha256")
411                        .and_then(|v| v.to_str().ok())
412                        .filter(|h| is_hex_sha256(h))
413                    {
414                        if sha256_hex_lower(&body_bytes) != signed_hash {
415                            return build_error_response(
416                                StatusCode::FORBIDDEN,
417                                "SignatureDoesNotMatch",
418                                "The request signature we calculated does not match the signature you provided",
419                                &request_id,
420                                detected.protocol,
421                            );
422                        }
423                    }
424                }
425            }
426            Err(fakecloud_aws::sigv4::SigV4Error::RequestTimeTooSkewed { .. }) => {
427                return build_error_response(
428                    StatusCode::FORBIDDEN,
429                    "RequestTimeTooSkewed",
430                    "The difference between the request time and the current time is too large",
431                    &request_id,
432                    detected.protocol,
433                );
434            }
435            Err(fakecloud_aws::sigv4::SigV4Error::InvalidDate(msg)) => {
436                return build_error_response(
437                    StatusCode::FORBIDDEN,
438                    "IncompleteSignature",
439                    &format!("Invalid x-amz-date: {msg}"),
440                    &request_id,
441                    detected.protocol,
442                );
443            }
444            Err(fakecloud_aws::sigv4::SigV4Error::Malformed(msg)) => {
445                return build_error_response(
446                    StatusCode::FORBIDDEN,
447                    "IncompleteSignature",
448                    &format!("Malformed SigV4 signature: {msg}"),
449                    &request_id,
450                    detected.protocol,
451                );
452            }
453            Err(fakecloud_aws::sigv4::SigV4Error::SignatureMismatch) => {
454                return build_error_response(
455                    StatusCode::FORBIDDEN,
456                    "SignatureDoesNotMatch",
457                    "The request signature we calculated does not match the signature you provided",
458                    &request_id,
459                    detected.protocol,
460                );
461            }
462            Err(fakecloud_aws::sigv4::SigV4Error::PresignedUrlExpired { .. }) => {
463                return build_error_response(
464                    StatusCode::FORBIDDEN,
465                    "AccessDenied",
466                    "Request has expired",
467                    &request_id,
468                    detected.protocol,
469                );
470            }
471            Err(fakecloud_aws::sigv4::SigV4Error::InvalidPresignExpires(_)) => {
472                return build_error_response(
473                    StatusCode::BAD_REQUEST,
474                    "AuthorizationQueryParametersError",
475                    "X-Amz-Expires must be a number between 1 and 604800 seconds",
476                    &request_id,
477                    detected.protocol,
478                );
479            }
480        }
481    }
482
483    // Build path segments. For S3 virtual-hosted-style requests the bucket
484    // lives in the Host header, not the path — prepend it so the S3 handler
485    // sees a uniform path-style request. SigV4 verification above already
486    // ran against the wire path, so this rewrite is signature-safe.
487    let wire_path = parts.uri.path();
488    let path = if detected.service == "s3" {
489        if let Some(bucket) = host_info.as_ref().and_then(|h| h.bucket.as_deref()) {
490            let prefix_with_slash = format!("/{bucket}/");
491            let is_bucket_root = wire_path.trim_end_matches('/') == format!("/{bucket}");
492            if wire_path.starts_with(&prefix_with_slash) || is_bucket_root {
493                wire_path.to_string()
494            } else if wire_path == "/" || wire_path.is_empty() {
495                format!("/{bucket}")
496            } else {
497                format!("/{bucket}{wire_path}")
498            }
499        } else {
500            wire_path.to_string()
501        }
502    } else {
503        wire_path.to_string()
504    };
505    let raw_query = parts.uri.query().unwrap_or("").to_string();
506    let path_segments: Vec<String> = path
507        .split('/')
508        .filter(|s| !s.is_empty())
509        .map(|s| s.to_string())
510        .collect();
511
512    // For JSON protocol, validate that non-empty bodies are valid JSON
513    if detected.protocol == AwsProtocol::Json
514        && !body_bytes.is_empty()
515        && serde_json::from_slice::<serde_json::Value>(&body_bytes).is_err()
516    {
517        return build_error_response(
518            StatusCode::BAD_REQUEST,
519            "SerializationException",
520            "Start of structure or map found where not expected",
521            &request_id,
522            AwsProtocol::Json,
523        );
524    }
525
526    // Merge query params with form body params for the Query family (awsQuery
527    // and ec2Query share identical form-encoded request bodies).
528    let mut all_params = query_params;
529    if matches!(
530        detected.protocol,
531        AwsProtocol::Query | AwsProtocol::Ec2Query
532    ) {
533        let body_params = protocol::parse_query_body(&body_bytes);
534        for (k, v) in body_params {
535            all_params.entry(k).or_insert(v);
536        }
537    }
538
539    // CloudWatch (`monitoring`) advertises awsJson1_0 alongside awsQuery. Its
540    // handlers all read the flat awsQuery param map, so when a client uses the
541    // JSON protocol we flatten the JSON body into that same map, leaving the
542    // handlers unchanged. The handler emits a JSON response for JSON callers.
543    if detected.protocol == AwsProtocol::Json && detected.service == "monitoring" {
544        let body_params = protocol::flatten_json_to_query(&body_bytes);
545        for (k, v) in body_params {
546            all_params.entry(k).or_insert(v);
547        }
548    }
549
550    let aws_request = AwsRequest {
551        service: detected.service.clone(),
552        action: detected.action.clone(),
553        region,
554        account_id: caller_principal
555            .as_ref()
556            .map(|p| p.account_id.clone())
557            .unwrap_or_else(|| config.account_id.clone()),
558        request_id: request_id.clone(),
559        headers: parts.headers,
560        query_params: all_params,
561        body: body_bytes,
562        body_stream: parking_lot::Mutex::new(body_stream),
563        path_segments,
564        raw_path: path,
565        raw_query,
566        method: parts.method,
567        is_query_protocol: matches!(
568            detected.protocol,
569            AwsProtocol::Query | AwsProtocol::Ec2Query
570        ),
571        access_key_id,
572        principal: caller_principal,
573    };
574
575    tracing::info!(
576        service = %aws_request.service,
577        action = %aws_request.action,
578        request_id = %aws_request.request_id,
579        "handling request"
580    );
581
582    // Opt-in IAM identity-policy enforcement. Runs before the service
583    // handler so a deny never reaches business logic. Root principals
584    // (both `test*` bypass AKIDs and the account's IAM root) are exempt,
585    // matching AWS behavior. Services that haven't opted in via
586    // `iam_enforceable()` are transparently skipped — the startup log
587    // lists which services are under enforcement so users always know.
588    if config.iam_mode.is_enabled()
589        && service.iam_enforceable()
590        && !is_root_bypass(aws_request.access_key_id.as_deref().unwrap_or(""))
591    {
592        if let Some(evaluator) = config.policy_evaluator.as_ref() {
593            if let Some(principal) = aws_request.principal.as_ref() {
594                if !principal.is_root() {
595                    // A request can need several authorizations -- one per
596                    // table in a batch, say -- and every one must allow it.
597                    let iam_actions = service.iam_actions_for(&aws_request);
598                    if !iam_actions.is_empty() {
599                        for iam_action in &iam_actions {
600                            let mut condition_context = build_condition_context(
601                                principal,
602                                remote_addr,
603                                &aws_request.region,
604                                is_secure_transport(&aws_request.headers),
605                            );
606                            // F3 keys riding on the resolved credential. STS
607                            // populates these at mint time so subsequent
608                            // requests under the credential can be evaluated
609                            // against `aws:MultiFactorAuthPresent`,
610                            // `aws:MultiFactorAuthAge`, `aws:TokenIssueTime`,
611                            // and `aws:FederatedProvider`. IAM user access
612                            // keys carry none of these, matching AWS.
613                            if let Some(rc) = resolved.as_ref() {
614                                condition_context.aws_mfa_present = Some(rc.mfa_present);
615                                condition_context.aws_token_issue_time = rc.token_issued_at;
616                                condition_context.aws_federated_provider =
617                                    rc.federated_provider.clone();
618                                // `aws:MultiFactorAuthAge` is "seconds since
619                                // MFA was asserted" — computed at evaluation
620                                // time from the token issue moment so the
621                                // value increases monotonically as the session
622                                // ages. Only set when the session was actually
623                                // minted with MFA; otherwise the key is
624                                // absent, matching AWS.
625                                if rc.mfa_present {
626                                    if let Some(issued) = rc.token_issued_at {
627                                        let age = chrono::Utc::now()
628                                            .signed_duration_since(issued)
629                                            .num_seconds()
630                                            .max(0);
631                                        condition_context.aws_mfa_age_seconds = Some(age);
632                                    }
633                                }
634                            }
635                            condition_context.service_keys =
636                                service.iam_condition_keys_for(&aws_request, iam_action);
637
638                            // ABAC: populate tag-based condition keys.
639                            // aws:ResourceTag/*
640                            match service.resource_tags_for(&iam_action.resource) {
641                                Some(tags) => condition_context.resource_tags = Some(tags),
642                                None => tracing::debug!(
643                                    target: "fakecloud::iam::audit",
644                                    service = %detected.service,
645                                    resource = %iam_action.resource,
646                                    "service does not expose resource tags for ABAC; skipping aws:ResourceTag/* evaluation"
647                                ),
648                            }
649                            // aws:RequestTag/* + aws:TagKeys
650                            match service.request_tags_from(&aws_request, iam_action.action) {
651                                Some(tags) => condition_context.request_tags = Some(tags),
652                                None => tracing::debug!(
653                                    target: "fakecloud::iam::audit",
654                                    service = %detected.service,
655                                    action = %iam_action.action_string(),
656                                    "service does not expose request tags for ABAC; skipping aws:RequestTag/* / aws:TagKeys evaluation"
657                                ),
658                            }
659                            // aws:PrincipalTag/*
660                            condition_context.principal_tags = principal.tags.clone();
661
662                            // Phase 2: fetch the resource-based policy (if
663                            // any) attached to the target resource and
664                            // pass it to the evaluator alongside the
665                            // principal's identity policies. The resource's
666                            // owning account is parsed from the ARN (#381
667                            // multi-account alignment); S3 ARNs have an
668                            // empty account field, so we fall back to the
669                            // server's configured account ID in that case.
670                            let resource_policy_json =
671                                config.resource_policy_provider.as_ref().and_then(|p| {
672                                    p.resource_policy(&detected.service, &iam_action.resource)
673                                });
674                            // Derive the resource-owning account. Prefer a provider
675                            // lookup (S3 ARNs carry no account, so the bucket's
676                            // owner is resolved from state — without this, account
677                            // A reaching account B's bucket would be mis-read as
678                            // same-account and skip B's bucket-policy requirement,
679                            // bug-audit 2026-05-28, 5.3), then fall back to the
680                            // account embedded in the ARN (SQS/SNS/Lambda/…), then
681                            // to the caller's account for wildcard / unscoped
682                            // actions (ListQueues, GetCallerIdentity).
683                            let resource_account_id = config
684                                .resource_policy_provider
685                                .as_ref()
686                                .and_then(|p| {
687                                    p.resource_owner_account(
688                                        &detected.service,
689                                        &iam_action.resource,
690                                    )
691                                })
692                                .or_else(|| parse_account_from_arn(&iam_action.resource))
693                                .unwrap_or_else(|| principal.account_id.clone());
694                            // SCP ceiling: resolve the inherited SCP chain
695                            // for this principal (management accounts and
696                            // service-linked roles come back as `None`, in
697                            // which case the evaluator treats the layer as
698                            // absent). Audit breadcrumbs emitted by the
699                            // resolver itself, not here.
700                            let scps = config
701                                .scp_resolver
702                                .as_ref()
703                                .and_then(|r| r.scps_for(principal));
704                            let decision = evaluator.evaluate_with_resource_policy(
705                                principal,
706                                iam_action,
707                                &condition_context,
708                                resource_policy_json.as_deref(),
709                                &resource_account_id,
710                                &caller_session_policies,
711                                scps.as_deref(),
712                            );
713                            if !decision.is_allow() {
714                                tracing::warn!(
715                                    target: "fakecloud::iam::audit",
716                                    service = %detected.service,
717                                    action = %iam_action.action_string(),
718                                    resource = %iam_action.resource,
719                                    principal = %principal.arn,
720                                    resource_policy_present = resource_policy_json.is_some(),
721                                    decision = ?decision,
722                                    mode = %config.iam_mode,
723                                    request_id = %request_id,
724                                    "IAM policy evaluation denied request"
725                                );
726                                if config.iam_mode.is_strict() {
727                                    // Real AWS includes an "Encoded
728                                    // authorization failure message" suffix
729                                    // on AccessDeniedException — an opaque
730                                    // base64+zlib JSON blob that the caller
731                                    // can pass to STS
732                                    // `DecodeAuthorizationMessage` to
733                                    // recover the structured deny reason
734                                    // (action, principal, matched
735                                    // statements, condition context). We
736                                    // produce the same blob inline so
737                                    // existing tooling that decodes deny
738                                    // reasons works against fakecloud.
739                                    let context_summary = serde_json::json!({
740                                        "aws:PrincipalArn": principal.arn,
741                                        "aws:PrincipalAccount": principal.account_id,
742                                        "aws:RequestedRegion": condition_context
743                                            .aws_requested_region
744                                            .clone()
745                                            .unwrap_or_default(),
746                                        "aws:SecureTransport": condition_context
747                                            .aws_secure_transport
748                                            .unwrap_or(false),
749                                        "aws:Action": iam_action.action_string(),
750                                        "aws:Resource": iam_action.resource,
751                                        "decision": format!("{:?}", decision),
752                                    });
753                                    let action_string = iam_action.action_string();
754                                    let encoded = crate::auth_message::encode_deny(
755                                        matches!(decision, crate::auth::IamDecision::ExplicitDeny),
756                                        Some(&action_string),
757                                        Some(&principal.arn),
758                                        Vec::new(),
759                                        Some(context_summary),
760                                    );
761                                    return build_error_response(
762                                    StatusCode::FORBIDDEN,
763                                    "AccessDeniedException",
764                                    &format!(
765                                        "User: {} is not authorized to perform: {} on resource: {} Encoded authorization failure message: {}",
766                                        principal.arn,
767                                        iam_action.action_string(),
768                                        iam_action.resource,
769                                        encoded,
770                                    ),
771                                    &request_id,
772                                    detected.protocol,
773                                );
774                                }
775                                // Soft mode: audit log already emitted; fall
776                                // through to the handler.
777                            }
778                        }
779                    } else {
780                        // Service opted in via `iam_enforceable()` but its
781                        // `iam_action_for` returned no `IamAction` for this
782                        // specific operation (e.g. S3's `s3_detect_action`
783                        // has `_ => return None` arms for unrecognized
784                        // sub-resources). Under strict enforcement that must
785                        // fail closed: an operation we cannot map to an IAM
786                        // action cannot be authorized, so serving it would be
787                        // a fail-open bypass of `--iam strict`. Deny by
788                        // default. In soft mode we preserve the historical
789                        // warn-and-allow so an incomplete mapping surfaces
790                        // during rollout without blocking traffic.
791                        tracing::warn!(
792                            target: "fakecloud::iam::audit",
793                            service = %detected.service,
794                            action = %aws_request.action,
795                            mode = %config.iam_mode,
796                            request_id = %request_id,
797                            "service is iam_enforceable but has no IamAction mapping for this action; denying under strict, allowing under soft"
798                        );
799                        if config.iam_mode.is_strict() {
800                            return build_error_response(
801                                StatusCode::FORBIDDEN,
802                                "AccessDeniedException",
803                                &format!(
804                                    "User: {} is not authorized to perform: {}: no IAM action mapping exists for this operation, so it cannot be authorized under strict IAM enforcement",
805                                    principal.arn, aws_request.action,
806                                ),
807                                &request_id,
808                                detected.protocol,
809                            );
810                        }
811                        // Soft mode: audit log emitted; fall through to the
812                        // handler.
813                    }
814                }
815            } else if aws_request.access_key_id.is_none() {
816                // Truly anonymous (unsigned) caller — no Authorization header at
817                // all. No identity policies exist, so authorization rests
818                // entirely on the resource policy (a bucket policy granting
819                // `Principal:"*"`) and public-read ACLs — mirroring AWS, which
820                // denies anonymous requests unless the resource is explicitly
821                // made public. Without this an anonymous request that reached an
822                // iam_enforceable service in enforcement mode would bypass
823                // authorization entirely.
824                //
825                // A request that carried an Authorization header but whose
826                // credential did not resolve (principal `None` with
827                // `access_key_id` `Some`) is intentionally left alone here: with
828                // SigV4 verification off, fakecloud does not reject unverified
829                // signed requests, and turning them into anonymous denials would
830                // change long-standing behavior.
831                let iam_actions = service.iam_actions_for(&aws_request);
832                if !iam_actions.is_empty() {
833                    for iam_action in &iam_actions {
834                        let now = chrono::Utc::now();
835                        let mut condition_context = ConditionContext {
836                            aws_source_ip: remote_addr.map(|sa| sa.ip()),
837                            aws_current_time: Some(now),
838                            aws_epoch_time: Some(now.timestamp()),
839                            aws_secure_transport: Some(is_secure_transport(&aws_request.headers)),
840                            aws_requested_region: Some(aws_request.region.clone()),
841                            ..Default::default()
842                        };
843                        condition_context.service_keys =
844                            service.iam_condition_keys_for(&aws_request, iam_action);
845                        let resource_policy_json =
846                            config.resource_policy_provider.as_ref().and_then(|p| {
847                                p.resource_policy(&detected.service, &iam_action.resource)
848                            });
849                        let policy_decision = evaluator.evaluate_anonymous(
850                            iam_action,
851                            &condition_context,
852                            resource_policy_json.as_deref(),
853                        );
854                        let policy_allows = policy_decision.is_allow();
855                        // An explicit Deny in the resource policy always wins, even
856                        // over a public-read ACL — matching AWS's Deny-overrides
857                        // precedence. Collapsing the decision to a bool and ORing the
858                        // ACL let a public ACL override an explicit anonymous Deny.
859                        let policy_explicit_deny =
860                            matches!(policy_decision, crate::auth::IamDecision::ExplicitDeny);
861                        let acl_allows = !policy_explicit_deny
862                            && config.resource_policy_provider.as_ref().is_some_and(|p| {
863                                p.public_acl_allows(
864                                    &detected.service,
865                                    &iam_action.resource,
866                                    iam_action.action,
867                                )
868                            });
869                        if !policy_allows && !acl_allows {
870                            tracing::warn!(
871                                target: "fakecloud::iam::audit",
872                                service = %detected.service,
873                                action = %iam_action.action_string(),
874                                resource = %iam_action.resource,
875                                resource_policy_present = resource_policy_json.is_some(),
876                                mode = %config.iam_mode,
877                                request_id = %request_id,
878                                "anonymous request denied: no public bucket policy or ACL grants the action"
879                            );
880                            if config.iam_mode.is_strict() {
881                                return build_error_response(
882                                    StatusCode::FORBIDDEN,
883                                    "AccessDenied",
884                                    "Access Denied",
885                                    &request_id,
886                                    detected.protocol,
887                                );
888                            }
889                            // Soft mode: audit log emitted; fall through to the handler.
890                        }
891                    }
892                } else {
893                    // Anonymous request to an iam_enforceable service whose
894                    // operation has no IamAction mapping. Mirror the signed
895                    // branch above: an operation we cannot map to an IAM action
896                    // cannot be authorized, so serving it would be a fail-open
897                    // bypass of `--iam strict`. Deny by default under strict;
898                    // soft mode warns and falls through.
899                    tracing::warn!(
900                        target: "fakecloud::iam::audit",
901                        service = %detected.service,
902                        action = %aws_request.action,
903                        mode = %config.iam_mode,
904                        request_id = %request_id,
905                        "anonymous request to iam_enforceable service has no IamAction mapping; denying under strict, allowing under soft"
906                    );
907                    if config.iam_mode.is_strict() {
908                        return build_error_response(
909                            StatusCode::FORBIDDEN,
910                            "AccessDenied",
911                            "Access Denied",
912                            &request_id,
913                            detected.protocol,
914                        );
915                    }
916                }
917            }
918        }
919    }
920
921    match service.handle(aws_request).await {
922        Ok(resp) => {
923            let mut builder = Response::builder()
924                .status(resp.status)
925                .header("x-amzn-requestid", &request_id)
926                .header("x-amz-request-id", &request_id);
927
928            if !resp.content_type.is_empty() {
929                builder = builder.header("content-type", &resp.content_type);
930            }
931
932            let has_content_length = resp
933                .headers
934                .iter()
935                .any(|(k, _)| k.as_str().eq_ignore_ascii_case("content-length"));
936
937            for (k, v) in &resp.headers {
938                builder = builder.header(k, v);
939            }
940
941            match resp.body {
942                ResponseBody::Bytes(b) => builder.body(Body::from(b)).unwrap(),
943                ResponseBody::File { file, size } => {
944                    let stream = tokio_util::io::ReaderStream::new(file);
945                    let body = Body::from_stream(stream);
946                    if !has_content_length {
947                        builder = builder.header("content-length", size.to_string());
948                    }
949                    builder.body(body).unwrap()
950                }
951            }
952        }
953        Err(err) => {
954            tracing::warn!(
955                service = %detected.service,
956                action = %detected.action,
957                error = %err,
958                "request failed"
959            );
960            let error_headers = err.response_headers().to_vec();
961            let mut resp = build_error_response_with_fields(
962                err.status(),
963                err.code(),
964                &err.message(),
965                &request_id,
966                detected.protocol,
967                err.extra_fields(),
968            );
969            for (k, v) in &error_headers {
970                if let (Ok(name), Ok(val)) = (
971                    k.parse::<http::header::HeaderName>(),
972                    v.parse::<http::header::HeaderValue>(),
973                ) {
974                    resp.headers_mut().insert(name, val);
975                }
976            }
977            resp
978        }
979    }
980}
981
982/// Configuration passed to the dispatch handler.
983#[derive(Clone)]
984pub struct DispatchConfig {
985    pub region: String,
986    pub account_id: String,
987    /// Whether to cryptographically verify SigV4 signatures on incoming
988    /// requests. Wired through from `--verify-sigv4` /
989    /// `FAKECLOUD_VERIFY_SIGV4`. Off by default.
990    pub verify_sigv4: bool,
991    /// IAM policy evaluation mode. Wired through from `--iam` /
992    /// `FAKECLOUD_IAM`. Defaults to [`IamMode::Off`]. Actual evaluation is
993    /// added in a later batch; today this field is plumbed but never
994    /// consulted.
995    pub iam_mode: IamMode,
996    /// Resolves access key IDs to their secrets and owning principals.
997    /// Required when `verify_sigv4` or `iam_mode != Off`. When `None`, both
998    /// features gracefully degrade to off-by-default behavior.
999    pub credential_resolver: Option<Arc<dyn CredentialResolver>>,
1000    /// Evaluates IAM identity policies for a resolved principal + action.
1001    /// Required when `iam_mode != Off`. When `None`, enforcement silently
1002    /// degrades to off even if `iam_mode` is set.
1003    pub policy_evaluator: Option<Arc<dyn IamPolicyEvaluator>>,
1004    /// Resolves resource-based policies (S3 bucket policies in the
1005    /// initial rollout) to hand to the evaluator alongside the
1006    /// principal's identity policies. `None` means the server was
1007    /// started without any resource-policy-owning service registered;
1008    /// dispatch then behaves as if no resource policy is attached to
1009    /// any resource, identical to the Phase 1 behavior.
1010    pub resource_policy_provider: Option<Arc<dyn ResourcePolicyProvider>>,
1011    /// Resolves the ordered SCP chain that applies to a principal's
1012    /// account (root-OU first, account-direct last). `None` means no
1013    /// organizations resolver has been registered — SCPs never gate
1014    /// any request in that case. Off-by-default matches the Batch 4
1015    /// contract: zero behavior change until a user calls
1016    /// `CreateOrganization` and the resolver is wired.
1017    pub scp_resolver: Option<Arc<dyn crate::auth::ScpResolver>>,
1018}
1019
1020impl std::fmt::Debug for DispatchConfig {
1021    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
1022        f.debug_struct("DispatchConfig")
1023            .field("region", &self.region)
1024            .field("account_id", &self.account_id)
1025            .field("verify_sigv4", &self.verify_sigv4)
1026            .field("iam_mode", &self.iam_mode)
1027            .field(
1028                "credential_resolver",
1029                &self
1030                    .credential_resolver
1031                    .as_ref()
1032                    .map(|_| "<CredentialResolver>"),
1033            )
1034            .field(
1035                "policy_evaluator",
1036                &self
1037                    .policy_evaluator
1038                    .as_ref()
1039                    .map(|_| "<IamPolicyEvaluator>"),
1040            )
1041            .field(
1042                "resource_policy_provider",
1043                &self
1044                    .resource_policy_provider
1045                    .as_ref()
1046                    .map(|_| "<ResourcePolicyProvider>"),
1047            )
1048            .field(
1049                "scp_resolver",
1050                &self.scp_resolver.as_ref().map(|_| "<ScpResolver>"),
1051            )
1052            .finish()
1053    }
1054}
1055
1056impl DispatchConfig {
1057    /// Minimal constructor for tests and call sites that don't care about the
1058    /// opt-in security features.
1059    pub fn new(region: impl Into<String>, account_id: impl Into<String>) -> Self {
1060        Self {
1061            region: region.into(),
1062            account_id: account_id.into(),
1063            verify_sigv4: false,
1064            iam_mode: IamMode::Off,
1065            credential_resolver: None,
1066            policy_evaluator: None,
1067            resource_policy_provider: None,
1068            scp_resolver: None,
1069        }
1070    }
1071}
1072
1073/// Extract the 12-digit account ID segment from an AWS ARN.
1074///
1075/// ARNs follow `arn:<partition>:<service>:<region>:<account>:<resource>`.
1076/// Identifies routes that opt into streaming request bodies. Returns
1077/// `Some((service, action_hint))` when the dispatch path should hand
1078/// the raw body to the service handler unbuffered, otherwise `None`
1079/// for the default buffered path. The handler reads the stream via
1080/// [`crate::service::AwsRequest::take_body_stream`].
1081///
1082/// Streaming-eligible routes today:
1083///
1084/// * `s3` PUT object — `PUT /<bucket>/<key>` with a SigV4 (or
1085///   presigned) auth header. Covers PutObject, UploadPart, and
1086///   UploadPartCopy. The S3 service spills to disk via
1087///   [`fakecloud_persistence::BodySource::File`] when the stream is
1088///   present.
1089/// * `ecr` OCI Distribution v2 blob upload — `PATCH` and `PUT` on
1090///   `/v2/{name}/blobs/uploads/{uuid}`. The ECR service spools the
1091///   stream into a per-upload temp file before computing the digest.
1092fn streaming_route(
1093    method: &http::Method,
1094    path: &str,
1095    headers: &http::HeaderMap,
1096    query_params: &HashMap<String, String>,
1097) -> Option<(&'static str, &'static str)> {
1098    // ECR OCI v2 blob upload (PATCH chunk + final PUT).
1099    if (method == http::Method::PATCH || method == http::Method::PUT)
1100        && path.starts_with("/v2/")
1101        && path.contains("/blobs/uploads/")
1102    {
1103        return Some(("ecr", ""));
1104    }
1105
1106    // S3 PutObject / UploadPart / UploadPartCopy. Detect either via
1107    // SigV4 service field in the Authorization header OR via a SigV4
1108    // presigned URL (X-Amz-Credential .../s3/...) OR a SigV2 presigned
1109    // URL (AWSAccessKeyId + Signature + Expires query parameters).
1110    if method == http::Method::PUT {
1111        let after = path.trim_start_matches('/');
1112        // Path-style PutObject is `PUT /<bucket>/<key>` (path contains a
1113        // slash); virtual-hosted-style is `PUT /<key>` with the bucket
1114        // in the Host header. For virtual-hosted, accept any non-empty
1115        // path so the key flows through the streaming dispatch — the
1116        // Host parser already routed this request to S3.
1117        let virtual_hosted_s3 = protocol::parse_routing_host_from_headers(headers)
1118            .filter(|h| h.service == "s3" && h.bucket.is_some())
1119            .is_some();
1120        if after.is_empty() || (!virtual_hosted_s3 && !after.contains('/')) {
1121            return None;
1122        }
1123        let header_s3 = headers
1124            .get("authorization")
1125            .and_then(|v| v.to_str().ok())
1126            .and_then(fakecloud_aws::sigv4::parse_sigv4)
1127            .map(|info| info.service == "s3")
1128            .unwrap_or(false);
1129        let presigned_v4_s3 = query_params
1130            .get("X-Amz-Credential")
1131            .and_then(|c| c.split('/').nth(3).map(|s| s.to_string()))
1132            .map(|service| service == "s3")
1133            .unwrap_or(false);
1134        let presigned_v2 = query_params.contains_key("AWSAccessKeyId")
1135            && query_params.contains_key("Signature")
1136            && query_params.contains_key("Expires");
1137        if header_s3 || presigned_v4_s3 || presigned_v2 {
1138            return Some(("s3", ""));
1139        }
1140    }
1141
1142    None
1143}
1144
1145/// Default request-body buffering cap. fakecloud reads the entire
1146/// request body into memory before handing it to a service handler,
1147/// so this ceiling caps RAM usage per in-flight request.
1148///
1149/// Default 1 GiB — comfortably above legitimate single S3 PutObject
1150/// payloads (AWS recommends multipart above ~100 MiB) and each
1151/// multipart part dispatches through here separately. Override with
1152/// `FAKECLOUD_MAX_REQUEST_BODY_BYTES` (decimal bytes) when running
1153/// stress tests that push past the default.
1154const DEFAULT_MAX_REQUEST_BODY_BYTES: usize = 1024 * 1024 * 1024;
1155
1156/// The server-wide buffered request body cap in bytes, from
1157/// `FAKECLOUD_MAX_REQUEST_BODY_BYTES` (default 1 GiB). Public so buffered
1158/// sub-proxies (e.g. the CloudFront viewer data plane) apply the SAME cap as
1159/// direct traffic rather than an inconsistent limit of their own.
1160pub fn max_request_body_bytes() -> usize {
1161    static CACHED: std::sync::OnceLock<usize> = std::sync::OnceLock::new();
1162    *CACHED.get_or_init(|| {
1163        std::env::var("FAKECLOUD_MAX_REQUEST_BODY_BYTES")
1164            .ok()
1165            .and_then(|s| s.parse::<usize>().ok())
1166            .filter(|&n| n > 0)
1167            .unwrap_or(DEFAULT_MAX_REQUEST_BODY_BYTES)
1168    })
1169}
1170
1171/// For the cross-account decision in IAM enforcement, the "resource
1172/// account" is the ARN's account segment. Some services (notably S3)
1173/// produce ARNs with an empty account field — for those we return
1174/// `None` and let the caller fall back to the server's configured
1175/// account ID. Malformed or non-ARN strings also return `None`.
1176fn parse_account_from_arn(arn: &str) -> Option<String> {
1177    let mut parts = arn.splitn(6, ':');
1178    if parts.next()? != "arn" {
1179        return None;
1180    }
1181    let _partition = parts.next()?;
1182    let _service = parts.next()?;
1183    let _region = parts.next()?;
1184    let account = parts.next()?;
1185    // Resource segment must exist (parts.next().is_some()) for the ARN
1186    // to be well-formed, but we don't consume its value here.
1187    parts.next()?;
1188    if account.is_empty() {
1189        None
1190    } else {
1191        Some(account.to_string())
1192    }
1193}
1194
1195/// Whether the request's `user-agent` (or `x-amz-user-agent`) carries the
1196/// `api/neptune` SDK-metadata token the `aws-sdk-neptune` client stamps in.
1197/// Used to disambiguate Neptune from RDS, which share the `rds` SigV4 scope
1198/// and endpoint. Matches the `api/neptune` token that AWS SDKs emit (a
1199/// leading `api/neptune` optionally followed by `#`/`/` and a version).
1200fn user_agent_indicates_neptune(headers: &http::HeaderMap) -> bool {
1201    for name in ["user-agent", "x-amz-user-agent"] {
1202        if let Some(ua) = headers.get(name).and_then(|v| v.to_str().ok()) {
1203            for part in ua.split_whitespace() {
1204                if let Some(rest) = part.strip_prefix("api/neptune") {
1205                    if rest.is_empty() || rest.starts_with('#') || rest.starts_with('/') {
1206                        return true;
1207                    }
1208                }
1209            }
1210        }
1211    }
1212    false
1213}
1214
1215/// Extract region from User-Agent header suffix `region/<region>`.
1216/// Whether the request's `user-agent` (or `x-amz-user-agent`) carries the
1217/// `api/docdb` SDK-metadata token the `aws-sdk-docdb` client stamps in. Used
1218/// to disambiguate DocumentDB from RDS, which share the `rds` SigV4 scope
1219/// and endpoint. Matches the `api/docdb` token that AWS SDKs emit (a leading
1220/// `api/docdb` optionally followed by `#`/`/` and a version).
1221fn user_agent_indicates_docdb(headers: &http::HeaderMap) -> bool {
1222    for name in ["user-agent", "x-amz-user-agent"] {
1223        if let Some(ua) = headers.get(name).and_then(|v| v.to_str().ok()) {
1224            for part in ua.split_whitespace() {
1225                if let Some(rest) = part.strip_prefix("api/docdb") {
1226                    if rest.is_empty() || rest.starts_with('#') || rest.starts_with('/') {
1227                        return true;
1228                    }
1229                }
1230            }
1231        }
1232    }
1233    false
1234}
1235
1236fn extract_region_from_user_agent(headers: &http::HeaderMap) -> Option<String> {
1237    let ua = headers.get("user-agent")?.to_str().ok()?;
1238    for part in ua.split_whitespace() {
1239        if let Some(region) = part.strip_prefix("region/") {
1240            if !region.is_empty() {
1241                return Some(region.to_string());
1242            }
1243        }
1244    }
1245    None
1246}
1247
1248fn build_error_response(
1249    status: StatusCode,
1250    code: &str,
1251    message: &str,
1252    request_id: &str,
1253    protocol: AwsProtocol,
1254) -> Response<Body> {
1255    build_error_response_with_fields(status, code, message, request_id, protocol, &[])
1256}
1257
1258fn build_error_response_with_fields(
1259    status: StatusCode,
1260    code: &str,
1261    message: &str,
1262    request_id: &str,
1263    protocol: AwsProtocol,
1264    extra_fields: &[(String, String)],
1265) -> Response<Body> {
1266    let (status, content_type, body) = match protocol {
1267        // awsQuery services (SQS, SNS, IAM, STS, RDS, ELBv2, CloudWatch,
1268        // AutoScaling, ...) share the `<ErrorResponse>` envelope.
1269        AwsProtocol::Query => {
1270            fakecloud_aws::error::xml_error_response(status, code, message, request_id)
1271        }
1272        // EC2 uses the distinct ec2Query error envelope
1273        // (`<Response><Errors><Error>...</Errors><RequestID>`). Only EC2 is
1274        // classified `Ec2Query`, so the other Query-protocol services above are
1275        // untouched.
1276        AwsProtocol::Ec2Query => {
1277            fakecloud_aws::ec2query::ec2_error_response(status, code, message, request_id)
1278        }
1279        AwsProtocol::Rest => fakecloud_aws::error::s3_xml_error_response_with_fields(
1280            status,
1281            code,
1282            message,
1283            request_id,
1284            extra_fields,
1285        ),
1286        AwsProtocol::Json | AwsProtocol::RestJson => {
1287            fakecloud_aws::error::json_error_response_with_fields(
1288                status,
1289                code,
1290                message,
1291                extra_fields,
1292            )
1293        }
1294    };
1295
1296    // S3 (and other REST-XML services) place the error code in
1297    // `x-amz-error-code` so HEAD responses — which HTTP forbids from
1298    // carrying a body — still surface the code. AWS SDKs read this header
1299    // when the body is empty. Emit it on every error response so HEAD,
1300    // OPTIONS, and any client that strips the body still see the code.
1301    // Backend errors regularly include newlines (multi-line stderr from
1302    // docker/podman/etc.); HTTP header values reject control characters,
1303    // so sanitize before insertion or the builder rejects the response
1304    // and the connection drops.
1305    let safe_code = sanitize_header_value(code);
1306    let safe_message = sanitize_header_value(message);
1307    let mut builder = Response::builder()
1308        .status(status)
1309        .header("content-type", content_type)
1310        .header("x-amzn-requestid", request_id)
1311        .header("x-amz-request-id", request_id);
1312    if let Ok(v) = http::HeaderValue::from_str(&safe_code) {
1313        builder = builder.header("x-amz-error-code", v);
1314    }
1315    if let Ok(v) = http::HeaderValue::from_str(&safe_message) {
1316        builder = builder.header("x-amz-error-message", v);
1317    }
1318    builder.body(Body::from(body)).unwrap_or_else(|_| {
1319        // Builder only fails if a header is invalid; we sanitized the two
1320        // we control, so the remaining ones (content-type, request id) are
1321        // ASCII and safe. This fallback exists purely so we never panic.
1322        Response::new(Body::empty())
1323    })
1324}
1325
1326/// Strip characters that HTTP header values reject (control bytes, CR/LF/TAB)
1327/// and truncate to a length that AWS SDKs handle cleanly. Backend tools
1328/// (docker, podman, kubectl, …) emit multi-line stderr, and forwarding that
1329/// raw into `x-amz-error-message` previously panicked the dispatcher.
1330fn sanitize_header_value(s: &str) -> String {
1331    const MAX_LEN: usize = 1024;
1332    let mut out = String::with_capacity(s.len().min(MAX_LEN));
1333    for ch in s.chars() {
1334        if out.len() >= MAX_LEN {
1335            break;
1336        }
1337        // Header values forbid CR, LF, and other control bytes (RFC 9110).
1338        // Replace with a single space so multi-line messages stay readable.
1339        if ch.is_control() {
1340            if !out.ends_with(' ') {
1341                out.push(' ');
1342            }
1343        } else {
1344            out.push(ch);
1345        }
1346    }
1347    out.trim().to_string()
1348}
1349
1350/// Build the [`ConditionContext`] passed to the IAM evaluator for one
1351/// request. Populates the 10 global condition keys from the resolved
1352/// principal + the HTTP request. Service-specific keys are deferred to
1353/// a follow-up batch and left empty.
1354/// For an unsigned request that no other detection rule claimed, return the
1355/// bucket name when the first path segment names an existing S3 bucket.
1356///
1357/// fakecloud serves every service from one endpoint, so an anonymous
1358/// path-style S3 request (`GET /bucket/key`, no SigV4) is indistinguishable
1359/// from an API Gateway execute-api call by headers alone. Bucket existence is
1360/// the disambiguator: if the segment is a real bucket, route to S3; otherwise
1361/// fall through to the apigateway catch-all. Uses the already-wired
1362/// `resource_policy_provider`, which resolves S3 bucket ownership from state
1363/// (`Some` => the bucket exists). Returns `None` when no provider is wired.
1364/// Recover the access key from a SigV2 presigned URL. AWS SigV2 presigning
1365/// puts the key in the `AWSAccessKeyId` query parameter alongside `Signature`
1366/// and `Expires`; all three must be present for the URL to be a SigV2 presign.
1367/// Returns None for SigV4 presigns (which use `X-Amz-Credential`) or unsigned
1368/// requests.
1369fn sigv2_presigned_access_key(query_params: &HashMap<String, String>) -> Option<String> {
1370    if query_params.contains_key("Signature") && query_params.contains_key("Expires") {
1371        query_params.get("AWSAccessKeyId").cloned()
1372    } else {
1373        None
1374    }
1375}
1376
1377/// True when `s` is a 64-character lowercase-hex SHA-256 digest — the form a
1378/// signed `x-amz-content-sha256` payload hash takes. Distinguishes a real body
1379/// hash from the `UNSIGNED-PAYLOAD` / `STREAMING-*` markers (shorter and
1380/// containing non-hex characters), so only genuine hashes are re-bound to the
1381/// buffered body.
1382fn is_hex_sha256(s: &str) -> bool {
1383    s.len() == 64 && s.bytes().all(|b| matches!(b, b'0'..=b'9' | b'a'..=b'f'))
1384}
1385
1386/// Lowercase-hex SHA-256 of `bytes`, used to re-bind a signed
1387/// `x-amz-content-sha256` to the buffered request body for non-S3 services.
1388fn sha256_hex_lower(bytes: &[u8]) -> String {
1389    use sha2::{Digest, Sha256};
1390    let digest = Sha256::digest(bytes);
1391    const HEX: &[u8] = b"0123456789abcdef";
1392    let mut out = String::with_capacity(64);
1393    for b in digest {
1394        out.push(HEX[(b >> 4) as usize] as char);
1395        out.push(HEX[(b & 0x0f) as usize] as char);
1396    }
1397    out
1398}
1399
1400fn anonymous_s3_bucket(uri: &http::Uri, config: &DispatchConfig) -> Option<String> {
1401    let provider = config.resource_policy_provider.as_ref()?;
1402    let segment = uri.path().split('/').find(|s| !s.is_empty())?.to_string();
1403    let arn = format!("arn:aws:s3:::{segment}");
1404    provider.resource_owner_account("s3", &arn).map(|_| segment)
1405}
1406
1407fn build_condition_context(
1408    principal: &Principal,
1409    remote_addr: Option<SocketAddr>,
1410    region: &str,
1411    secure_transport: bool,
1412) -> ConditionContext {
1413    let now = chrono::Utc::now();
1414    ConditionContext {
1415        aws_username: aws_username_from_principal(principal),
1416        aws_userid: Some(principal.user_id.clone()),
1417        aws_principal_arn: Some(principal.arn.clone()),
1418        aws_principal_account: Some(principal.account_id.clone()),
1419        aws_principal_type: Some(principal_type_label(principal.principal_type).to_string()),
1420        aws_source_ip: remote_addr.map(|sa| sa.ip()),
1421        aws_current_time: Some(now),
1422        aws_epoch_time: Some(now.timestamp()),
1423        aws_secure_transport: Some(secure_transport),
1424        aws_requested_region: Some(region.to_string()),
1425        // F3 keys: populated from the caller's session context when STS
1426        // mints credentials with MFA / SAML / OIDC / VPC-endpoint hints.
1427        // Default-None here so tests/dispatch sites that don't set them
1428        // safe-fail any policy referencing them — matching AWS for keys
1429        // that aren't asserted.
1430        aws_mfa_present: None,
1431        aws_mfa_age_seconds: None,
1432        aws_called_via: Vec::new(),
1433        aws_source_vpce: None,
1434        aws_source_vpc: None,
1435        aws_vpc_source_ip: None,
1436        aws_federated_provider: None,
1437        aws_token_issue_time: None,
1438        service_keys: Default::default(),
1439        resource_tags: None,
1440        request_tags: None,
1441        principal_tags: None,
1442    }
1443}
1444
1445/// `aws:username` is only set for IAM users, matching AWS. For assumed
1446/// roles, federated users, root, and unknown principals the key is
1447/// absent — operators that reference it without `IfExists` safe-fail.
1448fn aws_username_from_principal(principal: &Principal) -> Option<String> {
1449    if principal.principal_type != PrincipalType::User {
1450        return None;
1451    }
1452    let after = principal.arn.rsplit_once(":user/").map(|(_, s)| s)?;
1453    // Strip any IAM path prefix; bare username is the last segment.
1454    Some(after.rsplit('/').next().unwrap_or(after).to_string())
1455}
1456
1457/// AWS's `aws:PrincipalType` uses PascalCase identifiers, distinct from
1458/// the lowercase ones [`PrincipalType::as_str`] returns for ARNs.
1459fn principal_type_label(t: PrincipalType) -> &'static str {
1460    match t {
1461        PrincipalType::User => "User",
1462        PrincipalType::AssumedRole => "AssumedRole",
1463        PrincipalType::FederatedUser => "FederatedUser",
1464        PrincipalType::Root => "Account",
1465        PrincipalType::Unknown => "Unknown",
1466    }
1467}
1468
1469/// Best-effort detection of TLS-terminated requests. Direct HTTPS
1470/// connections are not yet supported by the fakecloud server (it speaks
1471/// plain HTTP), so the only signal is an `x-forwarded-proto: https`
1472/// header set by an upstream proxy. Anything else evaluates to `false`,
1473/// which matches the typical local-dev setup.
1474fn is_secure_transport(headers: &http::HeaderMap) -> bool {
1475    headers
1476        .get("x-forwarded-proto")
1477        .and_then(|v| v.to_str().ok())
1478        .map(|s| s.eq_ignore_ascii_case("https"))
1479        .unwrap_or(false)
1480}
1481
1482trait ProtocolExt {
1483    fn error_status(&self) -> StatusCode;
1484}
1485
1486impl ProtocolExt for AwsProtocol {
1487    fn error_status(&self) -> StatusCode {
1488        StatusCode::BAD_REQUEST
1489    }
1490}
1491
1492#[cfg(test)]
1493mod tests {
1494    use super::*;
1495
1496    #[test]
1497    fn default_max_request_body_bytes_is_one_gib() {
1498        // Without the env override, the cap defaults to 1 GiB. The
1499        // public function caches via OnceLock so only the first call
1500        // in the process matters; we assert the constant directly.
1501        assert_eq!(DEFAULT_MAX_REQUEST_BODY_BYTES, 1024 * 1024 * 1024);
1502    }
1503
1504    #[test]
1505    fn sigv2_presigned_access_key_extracted_with_signature_and_expires() {
1506        let mut q = HashMap::new();
1507        q.insert("AWSAccessKeyId".to_string(), "AKIAEXAMPLE".to_string());
1508        q.insert("Signature".to_string(), "abc%2Bdef".to_string());
1509        q.insert("Expires".to_string(), "1700000000".to_string());
1510        assert_eq!(
1511            sigv2_presigned_access_key(&q).as_deref(),
1512            Some("AKIAEXAMPLE")
1513        );
1514    }
1515
1516    #[test]
1517    fn sigv2_presigned_access_key_none_without_signature_or_expires() {
1518        // AWSAccessKeyId alone (e.g. a stray query param) is not a SigV2
1519        // presign and must not be treated as a credential.
1520        let mut q = HashMap::new();
1521        q.insert("AWSAccessKeyId".to_string(), "AKIAEXAMPLE".to_string());
1522        assert_eq!(sigv2_presigned_access_key(&q), None);
1523
1524        q.insert("Expires".to_string(), "1700000000".to_string());
1525        assert_eq!(
1526            sigv2_presigned_access_key(&q),
1527            None,
1528            "missing Signature must not qualify"
1529        );
1530    }
1531
1532    #[test]
1533    fn sigv2_presigned_access_key_none_for_unsigned_request() {
1534        assert_eq!(sigv2_presigned_access_key(&HashMap::new()), None);
1535    }
1536
1537    #[test]
1538    fn is_hex_sha256_accepts_real_digest_rejects_markers() {
1539        // A genuine 64-char lowercase-hex digest is a bindable body hash.
1540        assert!(is_hex_sha256(&sha256_hex_lower(b"hello")));
1541        assert!(is_hex_sha256(
1542            "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
1543        ));
1544        // The SigV4 payload markers are NOT hashes and must be skipped.
1545        assert!(!is_hex_sha256("UNSIGNED-PAYLOAD"));
1546        assert!(!is_hex_sha256("STREAMING-AWS4-HMAC-SHA256-PAYLOAD"));
1547        assert!(!is_hex_sha256("STREAMING-UNSIGNED-PAYLOAD-TRAILER"));
1548        // Wrong length or non-lowercase-hex characters are rejected.
1549        assert!(!is_hex_sha256("abc123"));
1550        assert!(!is_hex_sha256(
1551            "E3B0C44298FC1C149AFBF4C8996FB92427AE41E4649B934CA495991B7852B855"
1552        ));
1553    }
1554
1555    #[test]
1556    fn sha256_hex_lower_matches_known_vectors() {
1557        // Empty input -> the well-known SHA-256 of "".
1558        assert_eq!(
1559            sha256_hex_lower(b""),
1560            "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
1561        );
1562        assert_eq!(
1563            sha256_hex_lower(b"abc"),
1564            "ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad"
1565        );
1566        assert_eq!(sha256_hex_lower(b"abc").len(), 64);
1567    }
1568
1569    #[test]
1570    fn dispatch_config_new_defaults_to_off() {
1571        let cfg = DispatchConfig::new("us-east-1", "123456789012");
1572        assert_eq!(cfg.region, "us-east-1");
1573        assert_eq!(cfg.account_id, "123456789012");
1574        assert!(!cfg.verify_sigv4);
1575        assert_eq!(cfg.iam_mode, IamMode::Off);
1576    }
1577
1578    #[test]
1579    fn aws_username_strips_iam_path_for_users() {
1580        let p = Principal {
1581            arn: "arn:aws:iam::123456789012:user/engineering/alice".into(),
1582            user_id: "AIDAALICE".into(),
1583            account_id: "123456789012".into(),
1584            principal_type: PrincipalType::User,
1585            source_identity: None,
1586            tags: None,
1587        };
1588        assert_eq!(aws_username_from_principal(&p), Some("alice".into()));
1589    }
1590
1591    #[test]
1592    fn aws_username_unset_for_assumed_role() {
1593        let p = Principal {
1594            arn: "arn:aws:sts::123456789012:assumed-role/ops/session".into(),
1595            user_id: "AROAOPS:session".into(),
1596            account_id: "123456789012".into(),
1597            principal_type: PrincipalType::AssumedRole,
1598            source_identity: None,
1599            tags: None,
1600        };
1601        assert_eq!(aws_username_from_principal(&p), None);
1602    }
1603
1604    #[test]
1605    fn principal_type_label_matches_aws_casing() {
1606        assert_eq!(principal_type_label(PrincipalType::User), "User");
1607        assert_eq!(
1608            principal_type_label(PrincipalType::AssumedRole),
1609            "AssumedRole"
1610        );
1611        assert_eq!(principal_type_label(PrincipalType::Root), "Account");
1612    }
1613
1614    #[test]
1615    fn build_condition_context_populates_global_keys() {
1616        let p = Principal {
1617            arn: "arn:aws:iam::123456789012:user/alice".into(),
1618            user_id: "AIDAALICE".into(),
1619            account_id: "123456789012".into(),
1620            principal_type: PrincipalType::User,
1621            source_identity: None,
1622            tags: None,
1623        };
1624        let addr: SocketAddr = "10.0.0.1:54321".parse().unwrap();
1625        let ctx = build_condition_context(&p, Some(addr), "us-east-1", false);
1626        assert_eq!(ctx.aws_username.as_deref(), Some("alice"));
1627        assert_eq!(ctx.aws_userid.as_deref(), Some("AIDAALICE"));
1628        assert_eq!(
1629            ctx.aws_principal_arn.as_deref(),
1630            Some("arn:aws:iam::123456789012:user/alice")
1631        );
1632        assert_eq!(ctx.aws_principal_account.as_deref(), Some("123456789012"));
1633        assert_eq!(ctx.aws_principal_type.as_deref(), Some("User"));
1634        assert_eq!(
1635            ctx.aws_source_ip.map(|i| i.to_string()).as_deref(),
1636            Some("10.0.0.1")
1637        );
1638        assert_eq!(ctx.aws_requested_region.as_deref(), Some("us-east-1"));
1639        assert_eq!(ctx.aws_secure_transport, Some(false));
1640        assert!(ctx.aws_current_time.is_some());
1641        assert!(ctx.aws_epoch_time.is_some());
1642    }
1643
1644    #[test]
1645    fn is_secure_transport_reads_x_forwarded_proto() {
1646        let mut headers = http::HeaderMap::new();
1647        headers.insert("x-forwarded-proto", "https".parse().unwrap());
1648        assert!(is_secure_transport(&headers));
1649        headers.insert("x-forwarded-proto", "http".parse().unwrap());
1650        assert!(!is_secure_transport(&headers));
1651        let empty = http::HeaderMap::new();
1652        assert!(!is_secure_transport(&empty));
1653    }
1654
1655    #[test]
1656    fn parse_account_from_arn_extracts_standard_shapes() {
1657        assert_eq!(
1658            parse_account_from_arn("arn:aws:sqs:us-east-1:123456789012:queue"),
1659            Some("123456789012".to_string())
1660        );
1661        assert_eq!(
1662            parse_account_from_arn("arn:aws:iam::123456789012:user/alice"),
1663            Some("123456789012".to_string())
1664        );
1665    }
1666
1667    #[test]
1668    fn parse_account_from_arn_returns_none_for_s3_empty_account() {
1669        // S3 ARNs have both region and account empty.
1670        assert_eq!(parse_account_from_arn("arn:aws:s3:::my-bucket"), None);
1671        assert_eq!(
1672            parse_account_from_arn("arn:aws:s3:::my-bucket/path/to/key"),
1673            None
1674        );
1675    }
1676
1677    #[test]
1678    fn parse_account_from_arn_returns_none_for_malformed() {
1679        assert_eq!(parse_account_from_arn(""), None);
1680        assert_eq!(parse_account_from_arn("not-an-arn"), None);
1681        assert_eq!(parse_account_from_arn("arn:aws:sqs:us-east-1"), None);
1682        assert_eq!(parse_account_from_arn("arn:aws:sqs"), None);
1683    }
1684
1685    #[test]
1686    fn extract_region_from_user_agent_finds_region_segment() {
1687        let mut headers = http::HeaderMap::new();
1688        headers.insert(
1689            "user-agent",
1690            "aws-sdk-rust/1.0 os/linux region/eu-central-1"
1691                .parse()
1692                .unwrap(),
1693        );
1694        assert_eq!(
1695            extract_region_from_user_agent(&headers),
1696            Some("eu-central-1".to_string())
1697        );
1698    }
1699
1700    #[test]
1701    fn extract_region_from_user_agent_none_without_header() {
1702        let headers = http::HeaderMap::new();
1703        assert_eq!(extract_region_from_user_agent(&headers), None);
1704    }
1705
1706    #[test]
1707    fn extract_region_from_user_agent_ignores_empty_region() {
1708        let mut headers = http::HeaderMap::new();
1709        headers.insert("user-agent", "aws-sdk-java region/".parse().unwrap());
1710        assert_eq!(extract_region_from_user_agent(&headers), None);
1711    }
1712
1713    #[test]
1714    fn extract_region_from_user_agent_none_when_no_region_marker() {
1715        let mut headers = http::HeaderMap::new();
1716        headers.insert("user-agent", "curl/7.79.1".parse().unwrap());
1717        assert_eq!(extract_region_from_user_agent(&headers), None);
1718    }
1719
1720    #[test]
1721    fn aws_username_none_for_root() {
1722        let p = Principal {
1723            arn: "arn:aws:iam::123456789012:root".into(),
1724            user_id: "123456789012".into(),
1725            account_id: "123456789012".into(),
1726            principal_type: PrincipalType::Root,
1727            source_identity: None,
1728            tags: None,
1729        };
1730        assert_eq!(aws_username_from_principal(&p), None);
1731    }
1732
1733    #[test]
1734    fn aws_username_bare_no_path() {
1735        let p = Principal {
1736            arn: "arn:aws:iam::123456789012:user/bob".into(),
1737            user_id: "AIDABOB".into(),
1738            account_id: "123456789012".into(),
1739            principal_type: PrincipalType::User,
1740            source_identity: None,
1741            tags: None,
1742        };
1743        assert_eq!(aws_username_from_principal(&p), Some("bob".into()));
1744    }
1745
1746    #[test]
1747    fn principal_type_label_covers_federated_and_unknown() {
1748        assert_eq!(
1749            principal_type_label(PrincipalType::FederatedUser),
1750            "FederatedUser"
1751        );
1752        assert_eq!(principal_type_label(PrincipalType::Unknown), "Unknown");
1753    }
1754
1755    #[test]
1756    fn build_condition_context_marks_secure_when_flag_set() {
1757        let p = Principal {
1758            arn: "arn:aws:iam::123456789012:user/alice".into(),
1759            user_id: "AIDAALICE".into(),
1760            account_id: "123456789012".into(),
1761            principal_type: PrincipalType::User,
1762            source_identity: None,
1763            tags: None,
1764        };
1765        let ctx = build_condition_context(&p, None, "us-west-2", true);
1766        assert_eq!(ctx.aws_secure_transport, Some(true));
1767        assert!(ctx.aws_source_ip.is_none());
1768        assert_eq!(ctx.aws_requested_region.as_deref(), Some("us-west-2"));
1769    }
1770
1771    #[test]
1772    fn is_secure_transport_case_insensitive() {
1773        let mut headers = http::HeaderMap::new();
1774        headers.insert("x-forwarded-proto", "HTTPS".parse().unwrap());
1775        assert!(is_secure_transport(&headers));
1776    }
1777
1778    #[test]
1779    fn is_secure_transport_non_ascii_bytes_false() {
1780        let mut headers = http::HeaderMap::new();
1781        headers.insert(
1782            "x-forwarded-proto",
1783            http::HeaderValue::from_bytes(&[0xFF, 0xFE]).unwrap(),
1784        );
1785        assert!(!is_secure_transport(&headers));
1786    }
1787
1788    #[test]
1789    fn protocol_ext_error_status_is_bad_request() {
1790        assert_eq!(AwsProtocol::Query.error_status(), StatusCode::BAD_REQUEST);
1791        assert_eq!(AwsProtocol::Json.error_status(), StatusCode::BAD_REQUEST);
1792        assert_eq!(AwsProtocol::Rest.error_status(), StatusCode::BAD_REQUEST);
1793        assert_eq!(
1794            AwsProtocol::RestJson.error_status(),
1795            StatusCode::BAD_REQUEST
1796        );
1797    }
1798
1799    #[test]
1800    fn build_error_response_json_has_json_content_type() {
1801        let resp = build_error_response(
1802            StatusCode::BAD_REQUEST,
1803            "TestCode",
1804            "test msg",
1805            "req-1",
1806            AwsProtocol::Json,
1807        );
1808        assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
1809        let ct = resp
1810            .headers()
1811            .get("content-type")
1812            .unwrap()
1813            .to_str()
1814            .unwrap();
1815        assert!(ct.contains("json"));
1816        let rid = resp
1817            .headers()
1818            .get("x-amzn-requestid")
1819            .unwrap()
1820            .to_str()
1821            .unwrap();
1822        assert_eq!(rid, "req-1");
1823    }
1824
1825    #[test]
1826    fn build_error_response_rest_returns_xml_content_type() {
1827        let resp = build_error_response(
1828            StatusCode::NOT_FOUND,
1829            "NoSuchBucket",
1830            "bucket missing",
1831            "req-2",
1832            AwsProtocol::Rest,
1833        );
1834        assert_eq!(resp.status(), StatusCode::NOT_FOUND);
1835        let ct = resp
1836            .headers()
1837            .get("content-type")
1838            .unwrap()
1839            .to_str()
1840            .unwrap();
1841        assert!(ct.contains("xml"));
1842    }
1843
1844    #[test]
1845    fn build_error_response_query_returns_xml() {
1846        let resp = build_error_response(
1847            StatusCode::BAD_REQUEST,
1848            "InvalidParameter",
1849            "bad param",
1850            "req-3",
1851            AwsProtocol::Query,
1852        );
1853        let ct = resp
1854            .headers()
1855            .get("content-type")
1856            .unwrap()
1857            .to_str()
1858            .unwrap();
1859        assert!(ct.contains("xml"));
1860    }
1861
1862    /// Regression for issue #1539: multi-line backend errors (e.g. podman
1863    /// stderr) used to panic the dispatcher when stuffed into the
1864    /// `x-amz-error-message` HTTP header. The response must build cleanly
1865    /// and the header value must not contain control characters.
1866    #[test]
1867    fn build_error_response_with_multiline_message_does_not_panic() {
1868        let resp = build_error_response(
1869            StatusCode::INTERNAL_SERVER_ERROR,
1870            "ServiceException",
1871            "Lambda execution failed: container failed to start: docker start failed: \
1872             Error: unable to start container \"abc\": \
1873             failed to create new hosts file:\nhost-gateway is empty\n",
1874            "req-multi",
1875            AwsProtocol::Json,
1876        );
1877        assert_eq!(resp.status(), StatusCode::INTERNAL_SERVER_ERROR);
1878        let msg = resp
1879            .headers()
1880            .get("x-amz-error-message")
1881            .expect("x-amz-error-message must be set even when input contains newlines")
1882            .to_str()
1883            .unwrap();
1884        assert!(!msg.contains('\n'));
1885        assert!(!msg.contains('\r'));
1886        assert!(msg.contains("Lambda execution failed"));
1887        assert!(msg.contains("host-gateway is empty"));
1888    }
1889
1890    #[test]
1891    fn build_error_response_with_control_chars_strips_them() {
1892        let resp = build_error_response(
1893            StatusCode::BAD_REQUEST,
1894            "Code\twith\ttabs",
1895            "msg\x00with\x01nulls",
1896            "req-ctrl",
1897            AwsProtocol::Json,
1898        );
1899        let code = resp
1900            .headers()
1901            .get("x-amz-error-code")
1902            .unwrap()
1903            .to_str()
1904            .unwrap();
1905        let msg = resp
1906            .headers()
1907            .get("x-amz-error-message")
1908            .unwrap()
1909            .to_str()
1910            .unwrap();
1911        assert!(!code.contains('\t'));
1912        assert!(!msg.contains('\x00'));
1913        assert!(!msg.contains('\x01'));
1914    }
1915
1916    #[test]
1917    fn sanitize_header_value_truncates_long_input() {
1918        let huge = "x".repeat(5_000);
1919        let out = sanitize_header_value(&huge);
1920        assert!(out.len() <= 1024);
1921    }
1922
1923    #[test]
1924    fn sanitize_header_value_collapses_consecutive_control_runs() {
1925        let out = sanitize_header_value("a\n\n\n\rb");
1926        assert_eq!(out, "a b");
1927    }
1928
1929    #[test]
1930    fn dispatch_config_carries_opt_in_flags() {
1931        let cfg = DispatchConfig {
1932            region: "eu-west-1".to_string(),
1933            account_id: "000000000000".to_string(),
1934            verify_sigv4: true,
1935            iam_mode: IamMode::Strict,
1936            credential_resolver: None,
1937            policy_evaluator: None,
1938            resource_policy_provider: None,
1939            scp_resolver: None,
1940        };
1941        assert!(cfg.verify_sigv4);
1942        assert!(cfg.iam_mode.is_strict());
1943        assert!(cfg.resource_policy_provider.is_none());
1944        assert!(cfg.scp_resolver.is_none());
1945    }
1946
1947    fn s3_sigv4_headers() -> http::HeaderMap {
1948        let mut headers = http::HeaderMap::new();
1949        headers.insert(
1950            "authorization",
1951            "AWS4-HMAC-SHA256 Credential=test/20240101/us-east-1/s3/aws4_request, \
1952             SignedHeaders=host, Signature=fake"
1953                .parse()
1954                .unwrap(),
1955        );
1956        headers
1957    }
1958
1959    #[test]
1960    fn streaming_route_path_style_s3_put_object() {
1961        let headers = s3_sigv4_headers();
1962        assert_eq!(
1963            streaming_route(
1964                &http::Method::PUT,
1965                "/my-bucket/key.txt",
1966                &headers,
1967                &HashMap::new(),
1968            ),
1969            Some(("s3", "")),
1970        );
1971    }
1972
1973    #[test]
1974    fn streaming_route_path_style_create_bucket_skipped() {
1975        // `PUT /bucket` (no trailing key) is CreateBucket — must NOT
1976        // hit the streaming path.
1977        let headers = s3_sigv4_headers();
1978        assert_eq!(
1979            streaming_route(&http::Method::PUT, "/my-bucket", &headers, &HashMap::new(),),
1980            None,
1981        );
1982    }
1983
1984    #[test]
1985    fn streaming_route_virtual_hosted_s3_put_object() {
1986        let mut headers = s3_sigv4_headers();
1987        headers.insert(
1988            "host",
1989            "vhost-bucket.s3.us-east-1.localhost.localstack.cloud:4566"
1990                .parse()
1991                .unwrap(),
1992        );
1993        // Virtual-hosted PUT has no bucket in the URL path (`/<key>`),
1994        // so the slash check used for path-style would reject it. The
1995        // Host parser confirms this is virtual-hosted S3 and the key
1996        // flows through the streaming dispatch.
1997        assert_eq!(
1998            streaming_route(&http::Method::PUT, "/hello.txt", &headers, &HashMap::new(),),
1999            Some(("s3", "")),
2000        );
2001    }
2002
2003    #[test]
2004    fn streaming_route_virtual_hosted_s3_root_skipped() {
2005        // `PUT /` against a virtual-hosted Host = CreateBucket, which
2006        // is handled buffered. Empty path-after-slash must short-circuit.
2007        let mut headers = s3_sigv4_headers();
2008        headers.insert(
2009            "host",
2010            "vhost-bucket.s3.us-east-1.localhost.localstack.cloud:4566"
2011                .parse()
2012                .unwrap(),
2013        );
2014        assert_eq!(
2015            streaming_route(&http::Method::PUT, "/", &headers, &HashMap::new()),
2016            None,
2017        );
2018    }
2019
2020    #[test]
2021    fn streaming_route_ecr_blob_upload() {
2022        let headers = http::HeaderMap::new();
2023        assert_eq!(
2024            streaming_route(
2025                &http::Method::PATCH,
2026                "/v2/my-repo/blobs/uploads/abcd1234",
2027                &headers,
2028                &HashMap::new(),
2029            ),
2030            Some(("ecr", "")),
2031        );
2032        assert_eq!(
2033            streaming_route(
2034                &http::Method::PUT,
2035                "/v2/my-repo/blobs/uploads/abcd1234",
2036                &headers,
2037                &HashMap::new(),
2038            ),
2039            Some(("ecr", "")),
2040        );
2041    }
2042
2043    #[test]
2044    fn streaming_route_presigned_v4_s3_put() {
2045        let headers = http::HeaderMap::new();
2046        let mut query_params = HashMap::new();
2047        query_params.insert(
2048            "X-Amz-Credential".to_string(),
2049            "test/20240101/us-east-1/s3/aws4_request".to_string(),
2050        );
2051        assert_eq!(
2052            streaming_route(
2053                &http::Method::PUT,
2054                "/my-bucket/key.txt",
2055                &headers,
2056                &query_params,
2057            ),
2058            Some(("s3", "")),
2059        );
2060    }
2061
2062    #[test]
2063    fn streaming_route_non_s3_auth_header_skipped() {
2064        // Same path shape but the SigV4 service is lambda — must not
2065        // wire the streaming dispatch (Lambda has its own buffered path).
2066        let mut headers = http::HeaderMap::new();
2067        headers.insert(
2068            "authorization",
2069            "AWS4-HMAC-SHA256 Credential=test/20240101/us-east-1/lambda/aws4_request, \
2070             SignedHeaders=host, Signature=fake"
2071                .parse()
2072                .unwrap(),
2073        );
2074        assert_eq!(
2075            streaming_route(
2076                &http::Method::PUT,
2077                "/my-bucket/key.txt",
2078                &headers,
2079                &HashMap::new(),
2080            ),
2081            None,
2082        );
2083    }
2084
2085    #[test]
2086    fn streaming_route_get_skipped() {
2087        let headers = s3_sigv4_headers();
2088        assert_eq!(
2089            streaming_route(
2090                &http::Method::GET,
2091                "/my-bucket/key.txt",
2092                &headers,
2093                &HashMap::new(),
2094            ),
2095            None,
2096        );
2097    }
2098}