feat(signature-v4a): create SignatureV4a JavaScript implementation

.changeset/tall-pens-yell.md

@@ -0,0 +1,5 @@
+---
+"@smithy/signature-v4": minor
+---
+
+Adding Signature V4a implementation

packages/signature-v4/src/SignatureV4.ts

@@ -1,15 +1,10 @@
 import {
   AwsCredentialIdentity,
-  ChecksumConstructor,
-  DateInput,
   EventSigner,
   EventSigningArguments,
   FormattedEvent,
-  HashConstructor,
-  HeaderBag,
   HttpRequest,
   MessageSigner,
-  Provider,
   RequestPresigner,
   RequestPresigningArguments,
   RequestSigner,
@@ -20,8 +15,6 @@ import {
   StringSigner,
 } from "@smithy/types";
 import { toHex } from "@smithy/util-hex-encoding";
-import { normalizeProvider } from "@smithy/util-middleware";
-import { escapeUri } from "@smithy/util-uri-escape";
 import { toUint8Array } from "@smithy/util-utf8";
 
 import {
@@ -42,78 +35,20 @@ import {
 } from "./constants";
 import { createScope, getSigningKey } from "./credentialDerivation";
 import { getCanonicalHeaders } from "./getCanonicalHeaders";
-import { getCanonicalQuery } from "./getCanonicalQuery";
 import { getPayloadHash } from "./getPayloadHash";
 import { HeaderFormatter } from "./HeaderFormatter";
 import { hasHeader } from "./headerUtil";
 import { moveHeadersToQuery } from "./moveHeadersToQuery";
 import { prepareRequest } from "./prepareRequest";
-import { iso8601 } from "./utilDate";
+import { SignatureV4Base, SignatureV4CryptoInit, SignatureV4Init } from "./SignatureV4Base";
 
 /**
  * @public
  */
-export interface SignatureV4Init {
-  /**
-   * The service signing name.
-   */
-  service: string;
-
-  /**
-   * The region name or a function that returns a promise that will be
-   * resolved with the region name.
-   */
-  region: string | Provider<string>;
-
-  /**
-   * The credentials with which the request should be signed or a function
-   * that returns a promise that will be resolved with credentials.
-   */
-  credentials: AwsCredentialIdentity | Provider<AwsCredentialIdentity>;
-
-  /**
-   * A constructor function for a hash object that will calculate SHA-256 HMAC
-   * checksums.
-   */
-  sha256: ChecksumConstructor | HashConstructor;
-
-  /**
-   * Whether to uri-escape the request URI path as part of computing the
-   * canonical request string. This is required for every AWS service, except
-   * Amazon S3, as of late 2017.
-   *
-   * @default [true]
-   */
-  uriEscapePath?: boolean;
-
-  /**
-   * Whether to calculate a checksum of the request body and include it as
-   * either a request header (when signing) or as a query string parameter
-   * (when presigning). This is required for AWS Glacier and Amazon S3 and optional for
-   * every other AWS service as of late 2017.
-   *
-   * @default [true]
-   */
-  applyChecksum?: boolean;
-}
-
-/**
- * @public
- */
-export interface SignatureV4CryptoInit {
-  sha256: ChecksumConstructor | HashConstructor;
-}
-
-/**
- * @public
- */
-export class SignatureV4 implements RequestPresigner, RequestSigner, StringSigner, EventSigner, MessageSigner {
-  private readonly service: string;
-  private readonly regionProvider: Provider<string>;
-  private readonly credentialProvider: Provider<AwsCredentialIdentity>;
-  private readonly sha256: ChecksumConstructor | HashConstructor;
-  private readonly uriEscapePath: boolean;
-  private readonly applyChecksum: boolean;
+export class SignatureV4
+  extends SignatureV4Base
+  implements RequestPresigner, RequestSigner, StringSigner, EventSigner, MessageSigner
+{
   private readonly headerFormatter = new HeaderFormatter();
 
   constructor({
@@ -124,13 +59,14 @@ export class SignatureV4 implements RequestPresigner, RequestSigner, StringSigne
     sha256,
     uriEscapePath = true,
   }: SignatureV4Init & SignatureV4CryptoInit) {
-    this.service = service;
-    this.sha256 = sha256;
-    this.uriEscapePath = uriEscapePath;
-    // default to true if applyChecksum isn't set
-    this.applyChecksum = typeof applyChecksum === "boolean" ? applyChecksum : true;
-    this.regionProvider = normalizeProvider(region);
-    this.credentialProvider = normalizeProvider(credentials);
+    super({
+      applyChecksum,
+      credentials,
+      region,
+      service,
+      sha256,
+      uriEscapePath,
+    });
   }
 
   public async presign(originalRequest: HttpRequest, options: RequestPresigningArguments = {}): Promise<HttpRequest> {
@@ -148,7 +84,7 @@ export class SignatureV4 implements RequestPresigner, RequestSigner, StringSigne
     this.validateResolvedCredentials(credentials);
     const region = signingRegion ?? (await this.regionProvider());
 
-    const { longDate, shortDate } = formatDate(signingDate);
+    const { longDate, shortDate } = this.formatDate(signingDate);
     if (expiresIn > MAX_PRESIGNED_TTL) {
       return Promise.reject(
         "Signature version 4 presigned URLs" + " must have an expiration date less than one week in" + " the future"
@@ -167,7 +103,7 @@ export class SignatureV4 implements RequestPresigner, RequestSigner, StringSigne
     request.query[EXPIRES_QUERY_PARAM] = expiresIn.toString(10);
 
     const canonicalHeaders = getCanonicalHeaders(request, unsignableHeaders, signableHeaders);
-    request.query[SIGNED_HEADERS_QUERY_PARAM] = getCanonicalHeaderList(canonicalHeaders);
+    request.query[SIGNED_HEADERS_QUERY_PARAM] = this.getCanonicalHeaderList(canonicalHeaders);
 
     request.query[SIGNATURE_QUERY_PARAM] = await this.getSignature(
       longDate,
@@ -200,7 +136,7 @@ export class SignatureV4 implements RequestPresigner, RequestSigner, StringSigne
     { signingDate = new Date(), priorSignature, signingRegion, signingService }: EventSigningArguments
   ): Promise<string> {
     const region = signingRegion ?? (await this.regionProvider());
-    const { shortDate, longDate } = formatDate(signingDate);
+    const { shortDate, longDate } = this.formatDate(signingDate);
     const scope = createScope(shortDate, region, signingService ?? this.service);
     const hashedPayload = await getPayloadHash({ headers: {}, body: payload } as any, this.sha256);
     const hash = new this.sha256();
@@ -246,7 +182,7 @@ export class SignatureV4 implements RequestPresigner, RequestSigner, StringSigne
     const credentials = await this.credentialProvider();
     this.validateResolvedCredentials(credentials);
     const region = signingRegion ?? (await this.regionProvider());
-    const { shortDate } = formatDate(signingDate);
+    const { shortDate } = this.formatDate(signingDate);
 
     const hash = new this.sha256(await this.getSigningKey(credentials, region, shortDate, signingService));
     hash.update(toUint8Array(stringToSign));
@@ -267,7 +203,7 @@ export class SignatureV4 implements RequestPresigner, RequestSigner, StringSigne
     this.validateResolvedCredentials(credentials);
     const region = signingRegion ?? (await this.regionProvider());
     const request = prepareRequest(requestToSign);
-    const { longDate, shortDate } = formatDate(signingDate);
+    const { longDate, shortDate } = this.formatDate(signingDate);
     const scope = createScope(shortDate, region, signingService ?? this.service);
 
     request.headers[AMZ_DATE_HEADER] = longDate;
@@ -291,75 +227,24 @@ export class SignatureV4 implements RequestPresigner, RequestSigner, StringSigne
     request.headers[AUTH_HEADER] =
       `${ALGORITHM_IDENTIFIER} ` +
       `Credential=${credentials.accessKeyId}/${scope}, ` +
-      `SignedHeaders=${getCanonicalHeaderList(canonicalHeaders)}, ` +
+      `SignedHeaders=${this.getCanonicalHeaderList(canonicalHeaders)}, ` +
       `Signature=${signature}`;
 
     return request;
   }
 
-  private createCanonicalRequest(request: HttpRequest, canonicalHeaders: HeaderBag, payloadHash: string): string {
-    const sortedHeaders = Object.keys(canonicalHeaders).sort();
-    return `${request.method}
-${this.getCanonicalPath(request)}
-${getCanonicalQuery(request)}
-${sortedHeaders.map((name) => `${name}:${canonicalHeaders[name]}`).join("\n")}
-
-${sortedHeaders.join(";")}
-${payloadHash}`;
-  }
-
-  private async createStringToSign(
-    longDate: string,
-    credentialScope: string,
-    canonicalRequest: string
-  ): Promise<string> {
-    const hash = new this.sha256();
-    hash.update(toUint8Array(canonicalRequest));
-    const hashedRequest = await hash.digest();
-
-    return `${ALGORITHM_IDENTIFIER}
-${longDate}
-${credentialScope}
-${toHex(hashedRequest)}`;
-  }
-
-  private getCanonicalPath({ path }: HttpRequest): string {
-    if (this.uriEscapePath) {
-      // Non-S3 services, we normalize the path and then double URI encode it.
-      // Ref: "Remove Dot Segments" https://datatracker.ietf.org/doc/html/rfc3986#section-5.2.4
-      const normalizedPathSegments = [];
-      for (const pathSegment of path.split("/")) {
-        if (pathSegment?.length === 0) continue;
-        if (pathSegment === ".") continue;
-        if (pathSegment === "..") {
-          normalizedPathSegments.pop();
-        } else {
-          normalizedPathSegments.push(pathSegment);
-        }
-      }
-      // Joining by single slashes to remove consecutive slashes.
-      const normalizedPath = `${path?.startsWith("/") ? "/" : ""}${normalizedPathSegments.join("/")}${
-        normalizedPathSegments.length > 0 && path?.endsWith("/") ? "/" : ""
-      }`;
-
-      // Double encode and replace non-standard characters !'()* according to RFC 3986
-      const doubleEncoded = escapeUri(normalizedPath);
-      return doubleEncoded.replace(/%2F/g, "/");
-    }
-
-    // For S3, we shouldn't normalize the path. For example, object name
-    // my-object//example//photo.user should not be normalized to
-    // my-object/example/photo.user
-    return path;
-  }
-
   private async getSignature(
     longDate: string,
     credentialScope: string,
     keyPromise: Promise<Uint8Array>,
     canonicalRequest: string
   ): Promise<string> {
-    const stringToSign = await this.createStringToSign(longDate, credentialScope, canonicalRequest);
+    const stringToSign = await this.createStringToSign(
+      longDate,
+      credentialScope,
+      canonicalRequest,
+      ALGORITHM_IDENTIFIER
+    );
 
     const hash = new this.sha256(await keyPromise);
     hash.update(toUint8Array(stringToSign));
@@ -374,26 +259,4 @@ ${toHex(hashedRequest)}`;
   ): Promise<Uint8Array> {
     return getSigningKey(this.sha256, credentials, shortDate, region, service || this.service);
   }
-
-  private validateResolvedCredentials(credentials: unknown) {
-    if (
-      typeof credentials !== "object" ||
-      // @ts-expect-error: Property 'accessKeyId' does not exist on type 'object'.ts(2339)
-      typeof credentials.accessKeyId !== "string" ||
-      // @ts-expect-error: Property 'secretAccessKey' does not exist on type 'object'.ts(2339)
-      typeof credentials.secretAccessKey !== "string"
-    ) {
-      throw new Error("Resolved credential object is not valid");
-    }
-  }
 }
-
-const formatDate = (now: DateInput): { longDate: string; shortDate: string } => {
-  const longDate = iso8601(now).replace(/[\-:]/g, "");
-  return {
-    longDate,
-    shortDate: longDate.slice(0, 8),
-  };
-};
-
-const getCanonicalHeaderList = (headers: object): string => Object.keys(headers).sort().join(";");