feat: S3 Express support

Sources/ClientRuntime/Config/Context+Config.swift

@@ -0,0 +1,49 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import class Smithy.Context
+import class Smithy.ContextBuilder
+import struct Smithy.AttributeKey
+
+public extension Context {
+
+    var clientConfig: DefaultClientConfiguration? {
+        get { get(key: clientConfigKey)?.clientConfig }
+        set { set(key: clientConfigKey, value: ClientConfigurationWrapper(clientConfig: newValue)) }
+    }
+}
+
+public extension ContextBuilder {
+
+    func withClientConfig(value: DefaultClientConfiguration?) -> Self {
+        let wrapped = ClientConfigurationWrapper(clientConfig: value)
+        attributes.set(key: clientConfigKey, value: wrapped)
+        return self
+    }
+}
+
+private let clientConfigKey = AttributeKey<ClientConfigurationWrapper>(name: "SmithySwiftClientConfigWrapper")
+
+/// A wrapper used to allow a client configuration object to be placed in Context, since client config is not Sendable.
+///
+/// Placing the client config into Context is safe because the client config is not modified after being placed into Context.
+/// Client config is unwrapped, then may be used to create a service client and make calls as part of performing an operation.
+///
+/// This type is public so that it may be accessed in other runtime modules.  It is protected as SPI because it is a cross-module
+/// implementation detail that does not affect customers.
+///
+/// `@unchecked Sendable` is used to make the wrapper Sendable even though it is technically not, due to the non-Sendable
+/// client config stored within.
+@_spi(ClientConfigWrapper)
+public final class ClientConfigurationWrapper: @unchecked Sendable {
+    public let clientConfig: DefaultClientConfiguration
+
+    init?(clientConfig: DefaultClientConfiguration?) {
+        guard let clientConfig else { return nil }
+        self.clientConfig = clientConfig
+    }
+}

Sources/ClientRuntime/Config/IdentityPropertyKeys.swift

@@ -0,0 +1,19 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import struct Smithy.AttributeKey
+
+public enum IdentityPropertyKeys {
+
+    /// The service client config to be used in credential resolution.
+    ///
+    /// Used only in conjunction with the `awsv4-s3express` auth scheme, which generates bucket-specific credentials
+    /// for use with the S3 Express service.
+    @_spi(ClientConfigWrapper)
+    public static let clientConfigWrapper =
+        AttributeKey<ClientConfigurationWrapper>(name: "ClientConfigurationWrapperIdentityKey")
+}

Sources/ClientRuntime/Endpoints/EndpointResolverMiddleware.swift

@@ -53,6 +53,8 @@ extension EndpointResolverMiddleware: ApplyEndpoint {
                 signingName = param.signingName
             case .sigV4A(let param):
                 signingName = param.signingName
+            case .sigV4S3Express(let param):
+                signingName = param.signingName
             case .none:
                 break
             }

Sources/ClientRuntime/Endpoints/EndpointsAuthSchemeResolver.swift

@@ -11,13 +11,15 @@ import enum SmithyHTTPAPI.EndpointPropertyValue
 public enum EndpointsAuthScheme: Equatable {
     case sigV4(SigV4Parameters)
     case sigV4A(SigV4AParameters)
+    case sigV4S3Express(SigV4Parameters)
     case none
 
     /// The name of the auth scheme
     public var name: String {
         switch self {
         case .sigV4: return "sigv4"
         case .sigV4A: return "sigv4a"
+        case .sigV4S3Express: return "sigv4-s3express"
         case .none: return "none"
         }
     }
@@ -36,6 +38,8 @@ extension EndpointsAuthScheme {
             self = .sigV4(try SigV4Parameters(from: dictionary))
         case "sigv4a":
             self = .sigV4A(try SigV4AParameters(from: dictionary))
+        case "sigv4-s3express":
+            self = .sigV4S3Express(try SigV4Parameters(from: dictionary))
         case "none":
             self = .none
         default:
@@ -156,7 +160,7 @@ public struct DefaultEndpointsAuthSchemeResolver: EndpointsAuthSchemeResolver {
     /// Supported auth schemes by the SDK
     let supportedAuthSchemes: Set<String>
 
-    public init(supportedAuthSchemes: Set<String> = ["sigv4", "sigv4a", "none"]) {
+    public init(supportedAuthSchemes: Set<String> = ["sigv4", "sigv4a", "sigv4-s3express", "none"]) {
         self.supportedAuthSchemes = supportedAuthSchemes
     }
 

Sources/ClientRuntime/Networking/Http/Middlewares/AuthSchemeMiddleware.swift

@@ -73,7 +73,14 @@ extension AuthSchemeMiddleware: SelectAuthScheme {
                         context: attributes
                     )
                     // Resolve identity using the resolver from auth scheme
-                    let identity = try await identityResolver.getIdentity(identityProperties: option.identityProperties)
+                    var modifiedIdentityProperties = option.identityProperties
+                    modifiedIdentityProperties.set(
+                        key: IdentityPropertyKeys.clientConfigWrapper,
+                        value: ClientConfigurationWrapper(clientConfig: attributes.clientConfig)
+                    )
+                    let identity = try await identityResolver.getIdentity(
+                        identityProperties: modifiedIdentityProperties
+                    )
                     // Save selected auth scheme
                     selectedAuthScheme = SelectedAuthScheme(
                         schemeID: option.schemeID,

Sources/SmithyHTTPAuth/CRTAdapters.swift

@@ -26,6 +26,7 @@ extension SigningAlgorithm {
         switch self {
         case .sigv4: return .signingV4
         case .sigv4a: return .signingV4Asymmetric
+        case .sigv4s3express: return .signingV4S3Express
         }
     }
 }

Sources/SmithyHTTPAuth/SigV4AuthScheme.swift

@@ -34,8 +34,9 @@ public struct SigV4AuthScheme: AuthScheme {
             value: context.isBidirectionalStreamingEnabled
         )
 
-        // Set signing name and signing region flags
-        updatedSigningProperties.set(key: SigningPropertyKeys.signingName, value: context.signingName)
+        // Set resolved signing name and signing region flags
+        let signingName = updatedSigningProperties.get(key: SigningPropertyKeys.signingName) ?? context.signingName
+        updatedSigningProperties.set(key: SigningPropertyKeys.signingName, value: signingName)
         updatedSigningProperties.set(key: SigningPropertyKeys.signingRegion, value: context.signingRegion)
 
         // Set expiration flag

Sources/SmithyHTTPAuthAPI/SigningConfigFields/SigningAlgorithm.swift

@@ -12,4 +12,6 @@ public enum SigningAlgorithm: String, Sendable {
     case sigv4
     ///  Signature Version 4 Asymmetric
     case sigv4a
+    /// Signature Version 4 for S3 Express
+    case sigv4s3express = "sigv4-s3express"
 }

smithy-swift-codegen/src/main/kotlin/software/amazon/smithy/swift/codegen/integration/middlewares/OperationEndpointResolverMiddleware.kt

@@ -52,8 +52,9 @@ open class OperationEndpointResolverMiddleware(
         // Write code that saves endpoint params to middleware context for use in auth scheme middleware when using rules-based auth scheme resolvers
         if (AuthSchemeResolverGenerator.usesRulesBasedAuthResolver(ctx)) {
             writer.write(
-                "context.set(key: \$N<EndpointParams>(name: \"EndpointParams\"), value: endpointParamsBlock(context))",
+                "context.set(key: \$N<EndpointParams>(name: \$S), value: endpointParamsBlock(context))",
                 SmithyTypes.AttributeKey,
+                "EndpointParams",
             )
         }
 

smithy-swift-codegen/src/test/kotlin/software/amazon/smithy/swift/codegen/requestandresponse/EventStreamTests.kt

@@ -210,7 +210,7 @@ extension EventStreamTestClientTypes.TestStream {
         val context = setupTests("eventstream.smithy", "aws.protocoltests.restjson#TestService")
         println(context.manifest.files)
         val contents = getFileContents(context.manifest, "Sources/Example/EventStreamTestClient.swift")
-        var expected = """
+        val expected = """
     public func testStreamOp(input: TestStreamOpInput) async throws -> TestStreamOpOutput {
         let context = Smithy.ContextBuilder()
                       .withMethod(value: .post)