feat: add credential scope field

Author: kuhe

.changeset/happy-adults-complain.md

@@ -0,0 +1,6 @@
+---
+"@smithy/middleware-endpoint": minor
+"@smithy/types": minor
+---
+
+support credential scope

packages/middleware-endpoint/src/adaptors/createConfigValueProvider.ts

@@ -24,6 +24,13 @@ export const createConfigValueProvider = <Config extends Record<string, unknown>
     }
     return configValue;
   };
+  if (configKey === "credentialScope" || canonicalEndpointParamKey === "CredentialScope") {
+    return async () => {
+      const credentials = typeof config.credentials === 'function' ? await config.credentials() : config.credentials;
+      const configValue: unknown = credentials?.credentialScope ?? credentials?.CredentialScope;
+      return configValue;
+    };
+  }
   if (configKey === "endpoint" || canonicalEndpointParamKey === "endpoint") {
     return async () => {
       const endpoint = await configProvider();

packages/types/src/identity/awsCredentialIdentity.ts

@@ -19,6 +19,11 @@ export interface AwsCredentialIdentity extends Identity {
    * present for temporary credentials.
    */
   readonly sessionToken?: string;
+
+  /**
+   * AWS credential scope for this set of credentials.
+   */
+  readonly credentialScope?: string;
 }
 
 /**