chore: get signingRegion from regionRegex

Author: trivikr

packages/config-resolver/src/regionInfo/getRegionInfo.ts

@@ -2,6 +2,7 @@ import { RegionInfo } from "@aws-sdk/types";
 
 import { getResolvedHostname } from "./getResolvedHostname";
 import { getResolvedPartition } from "./getResolvedPartition";
+import { isFipsRegion } from "./isFipsRegion";
 import { PartitionHash } from "./PartitionHash";
 import { RegionHash } from "./RegionHash";
 
@@ -17,17 +18,32 @@ export const getRegionInfo = (
 ): RegionInfo => {
   const partition = getResolvedPartition(region, { partitionHash });
   const resolvedRegion = partitionHash[partition]?.endpoint ?? region;
+
+  const hostname = getResolvedHostname(resolvedRegion, {
+    signingService,
+    regionHostname: regionHash[resolvedRegion]?.hostname,
+    partitionHostname: partitionHash[partition]?.hostname,
+  });
+
+  let signingRegion: string | undefined;
+  if (regionHash[resolvedRegion]?.signingRegion) {
+    signingRegion = regionHash[resolvedRegion].signingRegion;
+  } else if (isFipsRegion(region)) {
+    const regionRegex = partitionHash[partition].regionRegex
+      .replace("\\\\", "\\")
+      .replace(/^\^/g, "")
+      .replace(/\$$/g, "");
+    const regionRegexmatchArray = hostname.match(regionRegex);
+    if (regionRegexmatchArray) {
+      signingRegion = regionRegexmatchArray[0];
+    }
+  }
+
   return {
     partition,
     signingService,
-    hostname: getResolvedHostname(resolvedRegion, {
-      signingService,
-      regionHostname: regionHash[resolvedRegion]?.hostname,
-      partitionHostname: partitionHash[partition]?.hostname,
-    }),
-    ...(regionHash[resolvedRegion]?.signingRegion && {
-      signingRegion: regionHash[resolvedRegion].signingRegion,
-    }),
+    hostname,
+    ...(signingRegion && { signingRegion }),
     ...(regionHash[resolvedRegion]?.signingService && {
       signingService: regionHash[resolvedRegion].signingService,
     }),