Exempt presigned requests from default checksum

aws/rust-runtime/aws-inlineable/src/http_request_checksum.rs

@@ -30,6 +30,8 @@ use http_body::Body;
 use std::str::FromStr;
 use std::{fmt, mem};
 
+use crate::presigning_interceptors::PresigningMarker;
+
 /// Errors related to constructing checksum-validated HTTP requests
 #[derive(Debug)]
 pub(crate) enum Error {
@@ -202,6 +204,13 @@ where
 
         // Calculate the checksum if necessary
         if calculate_checksum {
+            let is_presigned_req = cfg.load::<PresigningMarker>().is_some();
+
+            // If this is a presigned request and the user has not set a checksum we short circuit
+            if is_presigned_req && checksum_algorithm.is_none() {
+                return Ok(());
+            }
+
             // If a checksum override is set in the ConfigBag we use that instead (currently only used by S3Express)
             // If we have made it this far without a checksum being set we set the default as Crc32
             let checksum_algorithm = incorporate_custom_default(checksum_algorithm, cfg)

aws/rust-runtime/aws-inlineable/src/presigning_interceptors.rs

@@ -26,7 +26,7 @@ use aws_smithy_runtime_api::client::runtime_components::{
     RuntimeComponents, RuntimeComponentsBuilder,
 };
 use aws_smithy_runtime_api::client::runtime_plugin::RuntimePlugin;
-use aws_smithy_types::config_bag::{ConfigBag, FrozenLayer, Layer};
+use aws_smithy_types::config_bag::{ConfigBag, FrozenLayer, Layer, Storable, StoreReplace};
 use std::borrow::Cow;
 
 /// Interceptor that tells the SigV4 signer to add the signature to query params,
@@ -63,6 +63,8 @@ impl Intercept for SigV4PresigningInterceptor {
                     .omit_default_content_length()
                     .omit_default_content_type(),
             );
+
+        cfg.interceptor_state().store_put(PresigningMarker);
         Ok(())
     }
 
@@ -125,3 +127,12 @@ impl RuntimePlugin for SigV4PresigningRuntimePlugin {
         Cow::Borrowed(&self.runtime_components)
     }
 }
+
+/// A marker struct to be stored in the ConfigBag allowing other interceptors to know that
+/// the current request is Presigned
+#[derive(Debug)]
+pub(crate) struct PresigningMarker;
+
+impl Storable for PresigningMarker {
+    type Storer = StoreReplace<Self>;
+}

aws/rust-runtime/aws-sigv4/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "aws-sigv4"
-version = "1.2.6"
+version = "1.2.7"
 authors = ["AWS Rust SDK Team <[email protected]>", "David Barsky <[email protected]>"]
 description = "SigV4 signer for HTTP requests and Event Stream messages."
 edition = "2021"

rust-runtime/aws-smithy-runtime/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "aws-smithy-runtime"
-version = "1.7.4"
+version = "1.7.5"
 authors = ["AWS Rust SDK Team <[email protected]>", "Zelda Hessler <[email protected]>"]
 description = "The new smithy runtime crate"
 edition = "2021"