cloud_sdk_reqwest/asynchronous/
client.rs

1use core::fmt;
2use std::sync::Arc;
3
4use cloud_sdk::Method;
5use cloud_sdk::authentication::{
6    AsyncAuthenticatedTransport, AuthenticatedRequest, CredentialGeneration,
7};
8use cloud_sdk::transport::{
9    BoundTransport, EndpointIdentity, EndpointIdentityError, ResponseAttempt, ResponseMetadata,
10    ResponseStorageSanitizer, ResponseWriter, StatusCode,
11};
12use cloud_sdk_sanitization::{SecretBuffer, sanitize_bytes};
13use reqwest::header::{AUTHORIZATION, HeaderName, HeaderValue};
14use reqwest::{Body, Client};
15
16use crate::shared::{
17    BearerCredential, BearerCredentialScope, BearerCredentialSnapshot, BearerRefreshHandoff,
18    BearerToken, CredentialStateError, CredentialStore, CredentialUpdateError, HttpsEndpoint,
19    TokenRefreshError, TokenRotationError, TransportError, capture_response_headers,
20    map_authentication_error, parse_rate_limit, parse_response_content_type,
21    validate_bearer_authentication,
22};
23
24use super::body::SanitizedBuffer;
25
26/// Hardened provider-neutral reqwest asynchronous bearer transport.
27///
28/// The adapter uses reqwest's Tokio-based execution internally but does not
29/// install or own a runtime. Callers must poll it from a compatible executor.
30#[derive(Clone)]
31pub struct AsyncClient {
32    client: Client,
33    endpoint: HttpsEndpoint,
34    scope: Arc<BearerCredentialScope>,
35    credentials: Arc<CredentialStore>,
36    allow_insecure_loopback: bool,
37}
38
39impl AsyncClient {
40    pub(super) fn new(
41        client: Client,
42        endpoint: HttpsEndpoint,
43        credential: BearerCredential,
44        allow_insecure_loopback: bool,
45    ) -> Self {
46        Self {
47            client,
48            endpoint,
49            scope: Arc::new(credential.scope),
50            credentials: Arc::new(CredentialStore::new(credential.token)),
51            allow_insecure_loopback,
52        }
53    }
54
55    /// Captures the current generation without exposing token bytes.
56    pub fn credential_snapshot(&self) -> Result<BearerCredentialSnapshot, CredentialStateError> {
57        self.credentials.snapshot()
58    }
59
60    /// Atomically replaces the token while retaining immutable scope.
61    pub fn rotate_bearer_token(
62        &self,
63        replacement: BearerToken,
64    ) -> Result<CredentialGeneration, CredentialUpdateError> {
65        self.credentials.rotate(replacement)
66    }
67
68    /// Validates and rotates mutable bytes, clearing the complete source.
69    pub fn rotate_bearer_token_from_mut_bytes(
70        &self,
71        source: &mut [u8],
72    ) -> Result<CredentialGeneration, TokenRotationError> {
73        self.credentials.rotate_from_mut_bytes(source)
74    }
75
76    /// Validates and rotates guarded storage, which clears on return.
77    pub fn rotate_bearer_token_from_secret_buffer(
78        &self,
79        source: SecretBuffer<'_>,
80    ) -> Result<CredentialGeneration, TokenRotationError> {
81        self.credentials.rotate_from_secret_buffer(source)
82    }
83
84    /// Installs a refresh only if its captured generation is still current.
85    pub fn refresh_bearer_token(
86        &self,
87        handoff: BearerRefreshHandoff,
88        replacement: BearerToken,
89    ) -> Result<CredentialGeneration, TokenRefreshError> {
90        self.credentials.refresh(handoff, replacement)
91    }
92
93    /// Validates refreshed mutable bytes, clears them, and rejects stale work.
94    pub fn refresh_bearer_token_from_mut_bytes(
95        &self,
96        handoff: BearerRefreshHandoff,
97        source: &mut [u8],
98    ) -> Result<CredentialGeneration, TokenRefreshError> {
99        self.credentials.refresh_from_mut_bytes(handoff, source)
100    }
101
102    /// Consumes guarded refreshed storage and rejects stale work.
103    pub fn refresh_bearer_token_from_secret_buffer(
104        &self,
105        handoff: BearerRefreshHandoff,
106        source: SecretBuffer<'_>,
107    ) -> Result<CredentialGeneration, TokenRefreshError> {
108        self.credentials.refresh_from_secret_buffer(handoff, source)
109    }
110
111    async fn send_inner(
112        &self,
113        authenticated: AuthenticatedRequest<'_, '_>,
114        response_writer: &mut ResponseWriter<'_>,
115    ) -> Result<(), TransportError> {
116        let mut response_attempt = response_writer
117            .begin_attempt()
118            .map_err(|_| TransportError::ResponseCommitFailed)?;
119        let endpoint_identity = self
120            .endpoint
121            .identity()
122            .map_err(|_| TransportError::AuthenticationEndpointMismatch)?;
123        validate_bearer_authentication(
124            endpoint_identity,
125            &self.scope,
126            authenticated.policy(),
127            self.allow_insecure_loopback,
128        )
129        .map_err(map_authentication_error)?;
130        let token_snapshot = self
131            .credentials
132            .snapshot()
133            .map_err(|_| TransportError::CredentialStateUnavailable)?;
134        let authorization = token_snapshot
135            .header_value()
136            .map_err(|_| TransportError::HeaderRejected)?;
137        drop(token_snapshot);
138        execute(
139            &self.client,
140            &self.endpoint,
141            authorization,
142            authenticated,
143            &mut response_attempt,
144        )
145        .await
146    }
147}
148
149pub(super) async fn execute(
150    client: &Client,
151    endpoint: &HttpsEndpoint,
152    authorization: HeaderValue,
153    authenticated: AuthenticatedRequest<'_, '_>,
154    response_writer: &mut ResponseAttempt<'_, '_>,
155) -> Result<(), TransportError> {
156    let request = authenticated.transport_request();
157    let url = endpoint
158        .compose(request.target())
159        .map_err(|_| TransportError::TargetRejected)?;
160    let mut outbound = client
161        .request(map_method(request.method())?, url)
162        .header(AUTHORIZATION, authorization);
163
164    for header in request.headers().as_slice() {
165        let name = HeaderName::from_bytes(header.name().as_str().as_bytes())
166            .map_err(|_| TransportError::HeaderRejected)?;
167        let mut value = HeaderValue::from_str(header.value().as_str())
168            .map_err(|_| TransportError::HeaderRejected)?;
169        value.set_sensitive(matches!(
170            header.sensitivity(),
171            cloud_sdk::transport::HeaderSensitivity::Sensitive
172        ));
173        outbound = outbound.header(name, value);
174    }
175    if !request.body().is_empty() && request.headers().get("content-type").is_none() {
176        return Err(TransportError::MissingContentType);
177    }
178    if !request.body().is_empty() {
179        let body = SanitizedBuffer::copy_from(request.body())
180            .map_err(|_| TransportError::RequestBodyAllocationFailed)?;
181        let _ =
182            u64::try_from(request.body().len()).map_err(|_| TransportError::RequestBodyTooLarge)?;
183        outbound = outbound.body(Body::from(body.into_bytes()));
184    }
185
186    let mut response = outbound.send().await.map_err(classify_reqwest_error)?;
187    endpoint
188        .verify_origin(response.url())
189        .map_err(|_| TransportError::ResponseOriginChanged)?;
190    if response.content_length().is_some_and(|length| {
191        u64::try_from(response_writer.body_capacity()).map_or(true, |cap| length > cap)
192    }) {
193        return Err(TransportError::ResponseTooLarge);
194    }
195    let status =
196        StatusCode::new(response.status().as_u16()).ok_or(TransportError::InvalidStatus)?;
197    let buffered = read_response(&mut response, response_writer.body_capacity()).await?;
198    capture_response_headers(
199        response.headers(),
200        response_writer
201            .headers_mut()
202            .map_err(|_| TransportError::ResponseCommitFailed)?,
203    )?;
204    let rate_limit = parse_rate_limit(response_writer.headers())?;
205    parse_response_content_type(response_writer.headers())?;
206    let body_len = buffered.len();
207    let initialized = response_writer
208        .body_mut()
209        .map_err(|_| TransportError::ResponseCommitFailed)?
210        .get_mut(..body_len)
211        .ok_or(TransportError::ResponseReadFailed)?;
212    initialized.copy_from_slice(buffered.as_ref());
213    let mut metadata = ResponseMetadata::EMPTY;
214    if let Some(value) = rate_limit {
215        metadata = metadata.with_rate_limit(value);
216    }
217    response_writer
218        .commit(status, body_len, metadata)
219        .map_err(|_| TransportError::ResponseCommitFailed)
220}
221
222impl AsyncAuthenticatedTransport for AsyncClient {
223    type Error = TransportError;
224
225    async fn send_authenticated<'transport, 'request, 'policy, 'writer>(
226        &'transport self,
227        request: AuthenticatedRequest<'request, 'policy>,
228        response: &'writer mut ResponseWriter<'_>,
229    ) -> Result<(), Self::Error>
230    where
231        'transport: 'writer,
232        'request: 'writer,
233        'policy: 'writer,
234    {
235        self.send_inner(request, response).await
236    }
237}
238
239impl ResponseStorageSanitizer for AsyncClient {
240    fn sanitize_response_storage(&self, response_storage: &mut [u8]) {
241        sanitize_bytes(response_storage);
242    }
243}
244
245impl BoundTransport for AsyncClient {
246    fn endpoint_identity(&self) -> Result<EndpointIdentity<'_>, EndpointIdentityError> {
247        self.endpoint.identity()
248    }
249}
250
251impl fmt::Debug for AsyncClient {
252    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
253        formatter
254            .debug_struct("AsyncClient")
255            .field("endpoint", &"[redacted]")
256            .field("scope", &"[redacted]")
257            .field("credentials", &"[redacted]")
258            .finish_non_exhaustive()
259    }
260}
261
262async fn read_response(
263    response: &mut reqwest::Response,
264    limit: usize,
265) -> Result<SanitizedBuffer, TransportError> {
266    let mut buffered = SanitizedBuffer::with_capacity(limit)
267        .map_err(|_| TransportError::ResponseBodyAllocationFailed)?;
268    loop {
269        let chunk = response
270            .chunk()
271            .await
272            .map_err(|_| TransportError::ResponseReadFailed)?;
273        let Some(chunk) = chunk else { break };
274        buffered
275            .extend_bounded(&chunk, limit)
276            .map_err(|_| TransportError::ResponseTooLarge)?;
277    }
278    Ok(buffered)
279}
280
281fn map_method(method: Method) -> Result<reqwest::Method, TransportError> {
282    reqwest::Method::from_bytes(method.as_str().as_bytes())
283        .map_err(|_| TransportError::MethodRejected)
284}
285
286fn classify_reqwest_error(error: reqwest::Error) -> TransportError {
287    if error.is_timeout() {
288        TransportError::TimedOut
289    } else if error.is_connect() {
290        TransportError::ConnectFailed
291    } else {
292        TransportError::RequestFailed
293    }
294}
cloud_sdk_reqwest/asynchronous/client.rs

cloud_sdk_reqwest/asynchronous/
client.rs
