cloud-sdk-reqwest 0.16.0

<p align="center">
  <b>optional provider-neutral reqwest boundary for cloud-sdk.</b><br>
  Provider crates, explicit API domains, security-first release gates, and transport-free core types.
</p>

<div align="center">
  <a href="https://crates.io/crates/cloud-sdk">cloud-sdk crate</a>
  |
  <a href="https://docs.rs/cloud-sdk-reqwest">Docs.rs</a>
  |
  <a href="https://github.com/valkyoth/cloud-sdk/blob/main/docs/RELEASE_PLAN.md">Release Plan</a>
  |
  <a href="https://github.com/valkyoth/cloud-sdk/blob/main/docs/threat-model.md">Threat Model</a>
  |
  <a href="https://github.com/valkyoth/cloud-sdk/blob/main/SECURITY.md">Security</a>
</div>

<br>

<p align="center">
  <a href="https://github.com/valkyoth/cloud-sdk">
    <img src="https://raw.githubusercontent.com/valkyoth/cloud-sdk/main/.github/images/cloud-sdk.webp" alt="cloud-sdk Rust crate overview">
  </a>
</p>

# cloud-sdk-reqwest

Optional provider-neutral transport adapter for the main
[`cloud-sdk`](https://github.com/valkyoth/cloud-sdk) workspace and
[`cloud-sdk`](https://crates.io/crates/cloud-sdk) crate.

The crate remains no_std and transport-free by default. Its non-default
`blocking-rustls`, `blocking-rustls-fips`, and `async-rustls` features provide
reviewed HTTPS implementations for every provider without adding transport
dependencies to provider crates.

Most users should start with:

```toml
[dependencies]
cloud-sdk = "0.23.0"
cloud-sdk-reqwest = { version = "0.16.0", features = ["blocking-rustls"] }
```

## Blocking Example

```rust,no_run
# #[cfg(feature = "blocking-rustls")]
# fn main() {
use std::time::Duration;

use cloud_sdk::Method;
use cloud_sdk::transport::{BlockingTransport, RequestTarget, TransportRequest};
use cloud_sdk_reqwest::blocking::{
    BearerToken, BlockingClientBuilder, HttpsEndpoint, RequestTimeouts,
    UserAgent,
};

let Ok(endpoint) = HttpsEndpoint::new("https://api.hetzner.cloud/v1") else { return };
let Ok(token) = BearerToken::new("replace-with-scoped-token") else { return };
let Ok(user_agent) = UserAgent::new("my-service/1.0") else { return };
let Ok(timeouts) = RequestTimeouts::new(
    Duration::from_secs(30),
    Duration::from_secs(10),
) else { return };
let Ok(mut client) = BlockingClientBuilder::new(endpoint, token, user_agent, timeouts).build()
else { return };

let Ok(target) = RequestTarget::new("/servers?page=1") else { return };
let request = TransportRequest::new(Method::Get, target);
let mut response_body = [0_u8; 65_536];
let Ok(response) = client.send(request, &mut response_body) else { return };

assert!(response.status().is_success());
# }
# #[cfg(not(feature = "blocking-rustls"))]
# fn main() {}
```

## Blocking FIPS Example

Use the same blocking API with the dedicated feature:

```toml
[dependencies]
cloud-sdk = "0.23.0"
cloud-sdk-reqwest = { version = "0.16.0", features = ["blocking-rustls-fips"] }
rustls = "=0.23.42"
```

```rust,no_run
# #[cfg(feature = "blocking-rustls-fips")]
# fn main() {
use rustls::RootCertStore;
use rustls::pki_types::{CertificateDer, CertificateRevocationListDer};
use cloud_sdk_reqwest::blocking::{BlockingClientBuilder, FipsTlsPolicy};

# fn configure(
#     builder: BlockingClientBuilder,
#     root_der: Vec<u8>,
#     crl_der: Vec<u8>,
# ) {
let mut roots = RootCertStore::empty();
let Ok(()) = roots.add(CertificateDer::from(root_der)) else { return };
let Ok(policy) = FipsTlsPolicy::new(
    roots,
    vec![CertificateRevocationListDer::from(crl_der)],
) else { return };
let Ok(_client) = builder.with_fips_tls_policy(policy).build() else { return };
# }
# }
# #[cfg(not(feature = "blocking-rustls-fips"))]
# fn main() {}
```

The application must authenticate, refresh, and supply complete CRLs for every
issuer in an accepted chain. Construction rejects missing roots, missing or
malformed CRLs, and a missing policy; handshakes reject unknown revocation
status and expired CRLs. Client construction also fails closed unless both the
provider and complete TLS client configuration report FIPS operation. If both
blocking features are enabled, this explicit FIPS configuration wins.

A crate feature is not an application or deployment compliance claim; callers
remain responsible for the validated module's security policy, approved
operating environment, reviewed application lockfile or vendored sources,
toolchain, entropy, deployment, and operational controls. See
[`docs/dependency-admission-reqwest-fips.md`](https://github.com/valkyoth/cloud-sdk/blob/main/docs/dependency-admission-reqwest-fips.md).

## Async Example

The async adapter uses reqwest's Tokio-based execution internally but does not
create or own a runtime. Call it from an active Tokio executor:

```rust,no_run
# #[cfg(feature = "async-rustls")]
# async fn example() {
use std::time::Duration;

use cloud_sdk::Method;
use cloud_sdk::transport::{AsyncTransport, RequestTarget, TransportRequest};
use cloud_sdk_reqwest::asynchronous::{
    AsyncClientBuilder, BearerToken, HttpsEndpoint, RequestTimeouts, UserAgent,
};

let Ok(endpoint) = HttpsEndpoint::new("https://api.hetzner.cloud/v1") else { return };
let Ok(token) = BearerToken::new("replace-with-scoped-token") else { return };
let Ok(user_agent) = UserAgent::new("my-service/1.0") else { return };
let Ok(timeouts) = RequestTimeouts::new(
    Duration::from_secs(30),
    Duration::from_secs(10),
) else { return };
let Ok(mut client) = AsyncClientBuilder::new(endpoint, token, user_agent, timeouts).build()
else { return };

let Ok(target) = RequestTarget::new("/servers?page=1") else { return };
let request = TransportRequest::new(Method::Get, target);
let mut response_body = [0_u8; 65_536];
let Ok(response) = AsyncTransport::send(&mut client, request, &mut response_body).await
else { return };

assert!(response.status().is_success());
# }
# fn main() {}
```

For a non-empty request body, set an explicit validated content type:

```rust
use cloud_sdk::transport::{ContentType, TransportRequest};
# use cloud_sdk::{Method, transport::RequestTarget};
# let Ok(target) = RequestTarget::new("/servers") else { return };

let request = TransportRequest::new(Method::Post, target)
    .with_body(br#"{"name":"example"}"#)
    .with_content_type(ContentType::JSON);
assert_eq!(request.content_type(), Some(ContentType::JSON));
```

## Enforced Policy

- HTTPS-only production endpoints with no embedded credentials, query, or
  fragment.
- Rustls with TLS 1.2 minimum; platform certificate verification for standard
  transports and mandatory deployment roots plus CRLs for FIPS.
- Explicit total and connect timeouts, each nonzero and at most 300 seconds.
- Explicit validated user agent and bounded bearer token.
- HTTP/1 and the system resolver are forced even under downstream reqwest
  HTTP/2 or Hickory DNS feature unification.
- No redirects, automatic retries, proxies, referer generation, or response
  decompression.
- Exact scheme, host, and port preservation after target composition.
- Caller-sized response buffers with overflow detection and cleanup.
- Strict all-or-none decimal parsing and propagation of exactly one
  `RateLimit-Limit`, `RateLimit-Remaining`, and `RateLimit-Reset` response
  header; duplicates fail closed.
- Async responses are buffered within the caller's capacity and copied only
  after complete success; cancellation leaves the caller buffer cleared.
- Payload-free errors and redacted client, token, target, and body diagnostics.

`BearerToken` clears its adapter-owned authorization bytes through
`cloud-sdk-sanitization`. It cannot clear the caller's original immutable
string or copies owned by reqwest, TLS, the operating system, or remote
services. Keep tokens scoped, rotate and revoke them, and erase caller-owned
mutable secret storage after transport use.

## Features

| Feature | Default | Effect |
| --- | --- | --- |
| `default` | yes | Empty; keeps the crate transport-free and `no_std`. |
| `std` | no | Enables only std support in first-party boundary crates. |
| `blocking-rustls` | no | Enables the hardened blocking reqwest/rustls adapter and sanitization boundary. |
| `blocking-rustls-fips` | no | Enables the blocking adapter with runtime-verified AWS-LC FIPS plus mandatory deployment roots and CRLs. |
| `async-rustls` | no | Enables the hardened async reqwest/rustls adapter; callers provide an active Tokio runtime. |

Reqwest's default features are disabled. The complete dependency and security
decision is recorded in
[`docs/dependency-admission-reqwest.md`](https://github.com/valkyoth/cloud-sdk/blob/main/docs/dependency-admission-reqwest.md).

Provider crates retain ownership of authentication, base URLs, request models,
response interpretation, and provider-specific errors. This crate must not
branch on provider names.