Усилить безопасность и надёжность выполнения операций

crates/crank-adapter-rest/src/client.rs

@@ -1,9 +1,18 @@
-use std::{collections::BTreeMap, time::Duration};
+use std::{
+    collections::BTreeMap,
+    env, io,
+    net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr},
+    sync::Arc,
+    time::Duration,
+};
 
 use crank_core::{HttpMethod, RestTarget};
+use futures_util::StreamExt;
 use reqwest::{
     Client,
+    dns::{Addrs, Name, Resolve, Resolving},
     header::{HeaderMap, HeaderName, HeaderValue},
+    redirect,
 };
 use serde_json::Value;
 
@@ -11,9 +20,19 @@ use crate::{RestAdapterError, RestRequest, RestResponse};
 
 #[derive(Clone, Debug)]
 pub struct RestAdapter {
-    client: Client,
+    client: Result<Client, Arc<str>>,
+    policy: OutboundHttpPolicy,
 }
 
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct OutboundHttpPolicy {
+    allowed_hosts: Vec<String>,
+    denied_hosts: Vec<String>,
+    max_response_bytes: usize,
+}
+
+const DEFAULT_MAX_RESPONSE_BYTES: usize = 4 * 1024 * 1024;
+
 impl Default for RestAdapter {
     fn default() -> Self {
         Self::new()
@@ -22,9 +41,25 @@ impl Default for RestAdapter {
 
 impl RestAdapter {
     pub fn new() -> Self {
-        Self {
-            client: Client::new(),
-        }
+        Self::with_policy(OutboundHttpPolicy::default())
+    }
+
+    pub fn from_env() -> Result<Self, RestAdapterError> {
+        Ok(Self::with_policy(OutboundHttpPolicy::from_env()?))
+    }
+
+    pub fn with_policy(policy: OutboundHttpPolicy) -> Self {
+        let resolver = Arc::new(PolicyDnsResolver {
+            policy: policy.clone(),
+        });
+        let client = Client::builder()
+            .redirect(redirect::Policy::none())
+            .no_proxy()
+            .dns_resolver(resolver)
+            .build()
+            .map_err(|error| Arc::<str>::from(error.to_string()));
+
+        Self { client, policy }
     }
 
     pub async fn execute(
@@ -33,9 +68,15 @@ impl RestAdapter {
         request: &RestRequest,
     ) -> Result<RestResponse, RestAdapterError> {
         let url = build_url(target, request)?;
+        self.policy.validate_url(&url)?;
         let headers = build_headers(target, request)?;
-        let mut builder = self
-            .client
+        let client =
+            self.client
+                .as_ref()
+                .map_err(|details| RestAdapterError::InvalidConfiguration {
+                    details: details.to_string(),
+                })?;
+        let mut builder = client
             .request(to_reqwest_method(target.method), url)
             .headers(headers)
             .timeout(Duration::from_millis(request.timeout_ms));
@@ -47,7 +88,7 @@ impl RestAdapter {
         let response = builder.send().await?;
         let status = response.status();
         let headers = normalize_headers(response.headers());
-        let body = decode_body(response).await?;
+        let body = decode_body(response, self.policy.max_response_bytes).await?;
 
         if !status.is_success() {
             return Err(RestAdapterError::UnexpectedStatus {
@@ -64,6 +105,254 @@ impl RestAdapter {
     }
 }
 
+impl Default for OutboundHttpPolicy {
+    fn default() -> Self {
+        Self {
+            allowed_hosts: Vec::new(),
+            denied_hosts: Vec::new(),
+            max_response_bytes: DEFAULT_MAX_RESPONSE_BYTES,
+        }
+    }
+}
+
+impl OutboundHttpPolicy {
+    pub fn from_env() -> Result<Self, RestAdapterError> {
+        let max_response_bytes = match env::var("CRANK_OUTBOUND_MAX_RESPONSE_BYTES") {
+            Ok(value) => {
+                value
+                    .parse::<usize>()
+                    .map_err(|_| RestAdapterError::InvalidConfiguration {
+                        details: "CRANK_OUTBOUND_MAX_RESPONSE_BYTES must be a positive integer"
+                            .to_owned(),
+                    })?
+            }
+            Err(env::VarError::NotPresent) => DEFAULT_MAX_RESPONSE_BYTES,
+            Err(error) => {
+                return Err(RestAdapterError::InvalidConfiguration {
+                    details: error.to_string(),
+                });
+            }
+        };
+        if max_response_bytes == 0 {
+            return Err(RestAdapterError::InvalidConfiguration {
+                details: "CRANK_OUTBOUND_MAX_RESPONSE_BYTES must be greater than zero".to_owned(),
+            });
+        }
+
+        Ok(Self {
+            allowed_hosts: host_patterns_from_env("CRANK_OUTBOUND_ALLOWED_HOSTS")?,
+            denied_hosts: host_patterns_from_env("CRANK_OUTBOUND_DENIED_HOSTS")?,
+            max_response_bytes,
+        })
+    }
+
+    pub fn allowing_hosts(hosts: impl IntoIterator<Item = impl Into<String>>) -> Self {
+        Self {
+            allowed_hosts: hosts.into_iter().map(Into::into).collect(),
+            ..Self::default()
+        }
+    }
+
+    pub fn with_max_response_bytes(mut self, max_response_bytes: usize) -> Self {
+        self.max_response_bytes = max_response_bytes;
+        self
+    }
+
+    pub fn validate_base_url(&self, base_url: &str) -> Result<(), RestAdapterError> {
+        let url = reqwest::Url::parse(base_url).map_err(|_| RestAdapterError::InvalidBaseUrl {
+            url: base_url.to_owned(),
+        })?;
+        self.validate_url(&url)
+    }
+
+    fn validate_url(&self, url: &reqwest::Url) -> Result<(), RestAdapterError> {
+        if !matches!(url.scheme(), "http" | "https")
+            || !url.username().is_empty()
+            || url.password().is_some()
+        {
+            return Err(RestAdapterError::TargetNotAllowed {
+                target: url.to_string(),
+            });
+        }
+        let host = url
+            .host_str()
+            .ok_or_else(|| RestAdapterError::TargetNotAllowed {
+                target: url.to_string(),
+            })?;
+        self.validate_host(host)?;
+        if !self.is_explicitly_allowed(host) && is_local_hostname(host) {
+            return Err(RestAdapterError::TargetNotAllowed {
+                target: host.to_owned(),
+            });
+        }
+        if let Ok(address) = host.parse::<IpAddr>()
+            && !self.is_explicitly_allowed(host)
+            && !is_public_ip(address)
+        {
+            return Err(RestAdapterError::TargetNotAllowed {
+                target: host.to_owned(),
+            });
+        }
+        Ok(())
+    }
+
+    fn validate_host(&self, host: &str) -> Result<(), RestAdapterError> {
+        let host = normalize_host(host);
+        let denied = self
+            .denied_hosts
+            .iter()
+            .any(|pattern| host_matches(pattern, &host));
+        if denied {
+            return Err(RestAdapterError::TargetNotAllowed { target: host });
+        }
+        Ok(())
+    }
+
+    fn is_explicitly_allowed(&self, host: &str) -> bool {
+        let host = normalize_host(host);
+        self.allowed_hosts
+            .iter()
+            .any(|pattern| host_matches(pattern, &host))
+    }
+}
+
+#[derive(Clone, Debug)]
+struct PolicyDnsResolver {
+    policy: OutboundHttpPolicy,
+}
+
+impl Resolve for PolicyDnsResolver {
+    fn resolve(&self, name: Name) -> Resolving {
+        let host = normalize_host(name.as_str());
+        let policy = self.policy.clone();
+        Box::pin(async move {
+            policy
+                .validate_host(&host)
+                .map_err(|error| boxed_io_error(error.to_string()))?;
+            let explicitly_allowed = policy.is_explicitly_allowed(&host);
+            let resolved = tokio::net::lookup_host((host.as_str(), 0))
+                .await
+                .map_err(|error| Box::new(error) as Box<dyn std::error::Error + Send + Sync>)?;
+            let addresses = resolved
+                .filter(|address| explicitly_allowed || is_public_ip(address.ip()))
+                .collect::<Vec<SocketAddr>>();
+            if addresses.is_empty() {
+                return Err(boxed_io_error(format!(
+                    "outbound target {host} did not resolve to an allowed address"
+                )));
+            }
+            Ok(Box::new(addresses.into_iter()) as Addrs)
+        })
+    }
+}
+
+fn boxed_io_error(message: String) -> Box<dyn std::error::Error + Send + Sync> {
+    Box::new(io::Error::new(io::ErrorKind::PermissionDenied, message))
+}
+
+fn host_patterns_from_env(name: &str) -> Result<Vec<String>, RestAdapterError> {
+    let value = match env::var(name) {
+        Ok(value) => value,
+        Err(env::VarError::NotPresent) => return Ok(Vec::new()),
+        Err(error) => {
+            return Err(RestAdapterError::InvalidConfiguration {
+                details: error.to_string(),
+            });
+        }
+    };
+    value
+        .split(',')
+        .map(str::trim)
+        .filter(|value| !value.is_empty())
+        .map(|value| {
+            let wildcard = value.starts_with("*.");
+            let normalized = normalize_host(value.trim_start_matches("*."));
+            let valid_ip = !wildcard && normalized.parse::<IpAddr>().is_ok();
+            if normalized.is_empty()
+                || normalized.contains('/')
+                || (!valid_ip && normalized.contains(':'))
+                || (wildcard && normalized.parse::<IpAddr>().is_ok())
+            {
+                return Err(RestAdapterError::InvalidConfiguration {
+                    details: format!("{name} contains an invalid host pattern: {value}"),
+                });
+            }
+            Ok(if wildcard {
+                format!("*.{normalized}")
+            } else {
+                normalized
+            })
+        })
+        .collect()
+}
+
+fn normalize_host(host: &str) -> String {
+    host.trim()
+        .trim_start_matches('[')
+        .trim_end_matches(']')
+        .trim_end_matches('.')
+        .to_ascii_lowercase()
+}
+
+fn is_local_hostname(host: &str) -> bool {
+    let host = normalize_host(host);
+    host == "localhost" || host.ends_with(".localhost")
+}
+
+fn host_matches(pattern: &str, host: &str) -> bool {
+    pattern.strip_prefix("*.").map_or_else(
+        || pattern == host,
+        |suffix| host != suffix && host.ends_with(&format!(".{suffix}")),
+    )
+}
+
+fn is_public_ip(address: IpAddr) -> bool {
+    match address {
+        IpAddr::V4(address) => is_public_ipv4(address),
+        IpAddr::V6(address) => is_public_ipv6(address),
+    }
+}
+
+fn is_public_ipv4(address: Ipv4Addr) -> bool {
+    let octets = address.octets();
+    !(address.is_private()
+        || address.is_loopback()
+        || address.is_link_local()
+        || address.is_broadcast()
+        || address.is_documentation()
+        || address.is_unspecified()
+        || address.is_multicast()
+        || octets[0] == 0
+        || (octets[0] == 100 && (64..=127).contains(&octets[1]))
+        || (octets[0] == 192 && octets[1] == 0 && octets[2] == 0)
+        || (octets[0] == 198 && (18..=19).contains(&octets[1]))
+        || octets[0] >= 240)
+}
+
+fn is_public_ipv6(address: Ipv6Addr) -> bool {
+    let segments = address.segments();
+    if let Some(address) = address.to_ipv4_mapped() {
+        return is_public_ipv4(address);
+    }
+    if segments[..6].iter().all(|segment| *segment == 0) {
+        let [a, b] = segments[6].to_be_bytes();
+        let [c, d] = segments[7].to_be_bytes();
+        return is_public_ipv4(Ipv4Addr::new(a, b, c, d));
+    }
+    !(address.is_unspecified()
+        || address.is_loopback()
+        || address.is_multicast()
+        || (segments[0] & 0xfe00) == 0xfc00
+        || (segments[0] & 0xffc0) == 0xfe80
+        || (segments[0] & 0xffc0) == 0xfec0
+        || (segments[0] == 0x0064
+            && segments[1] == 0xff9b
+            && segments[2..6].iter().all(|segment| *segment == 0))
+        || (segments[0] == 0x0064 && segments[1] == 0xff9b && segments[2] == 1)
+        || segments[0] == 0x2002
+        || (segments[0] == 0x2001 && matches!(segments[1], 0 | 0x0db8)))
+}
+
 fn build_url(target: &RestTarget, request: &RestRequest) -> Result<reqwest::Url, RestAdapterError> {
     let base_url =
         reqwest::Url::parse(&target.base_url).map_err(|_| RestAdapterError::InvalidBaseUrl {
@@ -127,8 +416,29 @@ fn insert_header(headers: &mut HeaderMap, name: &str, value: &str) -> Result<(),
     Ok(())
 }
 
-async fn decode_body(response: reqwest::Response) -> Result<Value, RestAdapterError> {
-    let bytes = response.bytes().await?;
+async fn decode_body(
+    response: reqwest::Response,
+    max_response_bytes: usize,
+) -> Result<Value, RestAdapterError> {
+    if response
+        .content_length()
+        .is_some_and(|length| length > max_response_bytes as u64)
+    {
+        return Err(RestAdapterError::ResponseTooLarge {
+            limit_bytes: max_response_bytes,
+        });
+    }
+    let mut stream = response.bytes_stream();
+    let mut bytes = Vec::new();
+    while let Some(chunk) = stream.next().await {
+        let chunk = chunk?;
+        if bytes.len().saturating_add(chunk.len()) > max_response_bytes {
+            return Err(RestAdapterError::ResponseTooLarge {
+                limit_bytes: max_response_bytes,
+            });
+        }
+        bytes.extend_from_slice(&chunk);
+    }
 
     if bytes.is_empty() {
         return Ok(Value::Null);

crates/crank-adapter-rest/src/error.rs

@@ -13,6 +13,12 @@ pub enum RestAdapterError {
     InvalidHeaderName { header: String },
     #[error("invalid header value for {header}")]
     InvalidHeaderValue { header: String },
+    #[error("outbound target is not allowed: {target}")]
+    TargetNotAllowed { target: String },
+    #[error("rest response exceeds the configured limit of {limit_bytes} bytes")]
+    ResponseTooLarge { limit_bytes: usize },
+    #[error("invalid outbound HTTP configuration: {details}")]
+    InvalidConfiguration { details: String },
     #[error("request failed")]
     Transport(#[from] reqwest::Error),
     #[error("sse collection window expired before stream completed")]

crates/crank-adapter-rest/src/lib.rs

@@ -8,7 +8,7 @@ use crank_core::{
     ProtocolAdapterError, RestTarget, RuntimeRequestContext, Target,
 };
 
-pub use client::RestAdapter;
+pub use client::{OutboundHttpPolicy, RestAdapter};
 pub use error::RestAdapterError;
 pub use model::{RestRequest, RestResponse};