Signature and Version parameters in the response

- added Lambda's config variable `VERSION_PARAMETER_NAME`
- added Signature and Version parameters into an image response
- added Signature parameter into a noimage response

Author: tg666

src/config/config.js

@@ -9,6 +9,7 @@ class Config {
             HOST: null,
             MODIFIER_SEPARATOR: ',',
             MODIFIER_ASSIGNER: ':',
+            VERSION_PARAMETER_NAME: '_v',
             SIGNATURE_PARAMETER_NAME: '_s',
             SIGNATURE_KEY: null,
             SIGNATURE_ALGORITHM: 'sha256',

src/image-server/image-server.js

@@ -34,7 +34,9 @@ class ImageServer {
         }
 
         // validate signature token
-        this._signatureStrategy.verifyToken(request.hasQuery(this._config.SIGNATURE_PARAMETER_NAME) ? request.getQuery(this._config.SIGNATURE_PARAMETER_NAME) : null, path);
+        const signatureToken = request.hasQuery(this._config.SIGNATURE_PARAMETER_NAME) ? request.getQuery(this._config.SIGNATURE_PARAMETER_NAME) : null;
+
+        this._signatureStrategy.verifyToken(signatureToken, path);
 
         // parse image info & modifiers
         const parts = path.split('/');
@@ -49,6 +51,10 @@ class ImageServer {
 
         const info = new ImageInfo(parts.join('/'));
 
+        if (request.hasQuery(this._config.VERSION_PARAMETER_NAME)) {
+            info.version = request.getQuery(this._config.VERSION_PARAMETER_NAME);
+        }
+
         if (null === info.extension) {
             throw new InvalidStateError('Missing file extension in requested path.');
         }
@@ -72,7 +78,7 @@ class ImageServer {
                 CacheControl: `public, max-age=${this._config.CACHE_MAX_AGE.toString()}`,
                 Expires: new Date(now.getTime() + (this._config.CACHE_MAX_AGE * 1000))
             }).promise().then(
-                () => this._responseFactory.createRedirectResponse(this._createLink(resource.info, modifierString)),
+                () => this._responseFactory.createRedirectResponse(this._createLink(resource.info, modifierString, signatureToken)),
                 e => {
                     throw new InvalidStateError(e.message);
                 }
@@ -96,15 +102,39 @@ class ImageServer {
         return `${basePath}${info.createCachedPath(modifierString)}`;
     }
 
-    _createLink(info, modifierString, addSignature = false) {
-        const host = null !== this._config.HOST ? this._config.HOST : `https://${this._config.CACHE_BUCKET}.s3.${this._s3.config.region}.amazonaws.com`;
-        let path = this._createCachedPath(info, modifierString);
+    _getHostUrl() {
+        return new URL(
+            null !== this._config.HOST ? this._config.HOST : `https://${this._config.CACHE_BUCKET}.s3.${this._s3.config.region}.amazonaws.com`
+        );
+    }
+
+    _createLink(info, modifierString, signatureToken = null) {
+        const url = this._getHostUrl();
+        url.pathname = this._createCachedPath(info, modifierString);
+
+        if (null !== signatureToken) {
+            url.searchParams.set(this._config.SIGNATURE_PARAMETER_NAME, signatureToken);
+        }
+
+        if (null !== info.version) {
+            url.searchParams.set(this._config.SIGNATURE_PARAMETER_NAME, info.version);
+        }
+
+        return url.toString();
+    }
+
+    _createNoImageLink(info, modifierString) {
+        const url = this._getHostUrl();
+        const path = this._createCachedPath(info, modifierString);
+        const signatureToken = this._signatureStrategy.createToken(path);
+
+        url.pathname = path;
 
-        if (addSignature) {
-            path += `?${this._config.SIGNATURE_PARAMETER_NAME}=${this._signatureStrategy.createToken(path)}`;
+        if (null !== signatureToken) {
+            url.searchParams.set(this._config.SIGNATURE_PARAMETER_NAME, signatureToken);
         }
 
-        return `${host}/${path}`;
+        return url.toString();
     }
 
     _getNoImageResponse(info, modifierString) {
@@ -114,7 +144,7 @@ class ImageServer {
             noImageInfo.extension = info.extension;
 
             return this._responseFactory.createRedirectResponse(
-                this._createLink(noImageInfo, modifierString, true)
+                this._createNoImageLink(noImageInfo, modifierString)
             );
         } catch (e) {
             return null;

src/resource/image-info.js

@@ -11,6 +11,7 @@ class ImageInfo {
         this._name = name.join('.');
         this._namespace = namespace.join('/');
         this._extension = extension;
+        this._version = null;
     }
 
     get name() {
@@ -29,6 +30,14 @@ class ImageInfo {
         this._extension = extension;
     }
 
+    get version() {
+        return this._version;
+    }
+
+    set version(version) {
+        this._version = version;
+    }
+
     createCachedPath(modifier) {
         const extension = null !== this.extension ? this.extension : SupportedType.getDefaultExtension();
 

template.yaml

@@ -127,6 +127,7 @@ Resources:
           BASE_PATH: !Ref BasePath
           MODIFIER_SEPARATOR: !Ref ModifierSeparator
           MODIFIER_ASSIGNER: !Ref ModifierAssigner
+          VERSION_PARAMETER_NAME: !Ref VersionParameterName
           SIGNATURE_PARAMETER_NAME: !Ref SignatureParameterName
           SIGNATURE_KEY: !Ref SignatureKey
           SIGNATURE_ALGORITHM: !Ref SignatureAlgorithm