From a53d6641c9803608e33f5a188ead68ae7c25ee4d Mon Sep 17 00:00:00 2001
From: Angelo Ashmore <angeloashmore@users.noreply.github.com>
Date: Wed, 15 Apr 2020 18:29:13 -1000
Subject: [PATCH 1/3] feat: s param and optional URL signing

---
 src/index.ts | 22 +++++++++++++++++++++-
 src/tests.ts | 21 +++++++++++++++++++++
 2 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/src/index.ts b/src/index.ts
index 7146151..c28db44 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,5 +1,7 @@
 // tslint:disable-next-line match-default-export-name
+import { createHash } from 'crypto';
 import { ParsedUrlQueryInput } from 'querystring';
+import * as urlHelpers from 'url';
 import { addQueryToUrl } from 'url-transformers';
 import { pickBy } from './helpers';
 import { catMaybesDictionary, mapValueIfDefined } from './helpers/maybe';
@@ -71,6 +73,7 @@ export type ImgixUrlQueryParams = {
     cs?: ImgixColorSpace;
     faceindex?: number;
     facepad?: number;
+    s?: string;
 };
 
 const pickTrueInObject = <K extends string>(obj: Record<K, boolean>): Partial<Record<K, true>> =>
@@ -87,6 +90,21 @@ const serializeImgixUrlQueryParamListValue = pipe(
     joinWithComma,
     undefinedIfEmptyString,
 );
+const addImgixUrlQueryParamSignature = (url: string, token?: string) => (
+    query: ParsedUrlQueryInput,
+) => {
+    if (token === undefined || query.hasOwnProperty('s')) return query;
+
+    const formattedQuery = urlHelpers.format({ query });
+    const { pathname } = new urlHelpers.URL(url);
+
+    const signatureBase = token + pathname + formattedQuery;
+    const signature = createHash('md5')
+        .update(signatureBase)
+        .digest('hex');
+
+    return { ...query, s: signature };
+};
 
 const mapToSerializedListValueIfDefined = mapValueIfDefined(serializeImgixUrlQueryParamListValue);
 
@@ -110,12 +128,14 @@ const serializeImgixUrlQueryParamValues = (query: ImgixUrlQueryParams): ParsedUr
             blur: query.blur,
             faceindex: query.faceindex,
             facepad: query.facepad,
+            s: query.s,
         }),
         catMaybesDictionary,
     )({});
 
-export const buildImgixUrl = (url: string) =>
+export const buildImgixUrl = (url: string, token?: string) =>
     pipe(
         serializeImgixUrlQueryParamValues,
+        addImgixUrlQueryParamSignature(url, token),
         query => addQueryToUrl({ url })({ queryToAppend: query }),
     );
diff --git a/src/tests.ts b/src/tests.ts
index 6b4c0c9..fb6b6ec 100644
--- a/src/tests.ts
+++ b/src/tests.ts
@@ -10,3 +10,24 @@ assert.strictEqual(
     }),
     'https://foo.com/?auto=format&w=300',
 );
+
+assert.strictEqual(
+    buildImgixUrl('https://foo.com')({
+        auto: {
+            format: true,
+        },
+        w: 300,
+        s: 'signature',
+    }),
+    'https://foo.com/?auto=format&w=300&s=signature',
+);
+
+assert.strictEqual(
+    buildImgixUrl('https://foo.com', 'token')({
+        auto: {
+            format: true,
+        },
+        w: 300,
+    }),
+    'https://foo.com/?auto=format&w=300&s=d82d76f9f31379083b452f98bcd7f670',
+);

From 57611f589dd55ed710a8af142e90b8b7a8c86add Mon Sep 17 00:00:00 2001
From: Angelo Ashmore <angeloashmore@users.noreply.github.com>
Date: Wed, 15 Apr 2020 18:39:55 -1000
Subject: [PATCH 2/3] docs: add link to imgix-blueprint on url signing

---
 src/index.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/index.ts b/src/index.ts
index c28db44..47fc9f9 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -98,6 +98,7 @@ const addImgixUrlQueryParamSignature = (url: string, token?: string) => (
     const formattedQuery = urlHelpers.format({ query });
     const { pathname } = new urlHelpers.URL(url);
 
+    // https://github.com/imgix/imgix-blueprint#securing-urls
     const signatureBase = token + pathname + formattedQuery;
     const signature = createHash('md5')
         .update(signatureBase)

From 3ba8004fbb927e0416dcbb20facf71e30fe78936 Mon Sep 17 00:00:00 2001
From: Angelo Ashmore <angeloashmore@users.noreply.github.com>
Date: Wed, 15 Apr 2020 18:52:14 -1000
Subject: [PATCH 3/3] test: add token to signature passthrough test

---
 src/tests.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests.ts b/src/tests.ts
index fb6b6ec..b9e43b2 100644
--- a/src/tests.ts
+++ b/src/tests.ts
@@ -12,7 +12,7 @@ assert.strictEqual(
 );
 
 assert.strictEqual(
-    buildImgixUrl('https://foo.com')({
+    buildImgixUrl('https://foo.com', 'token')({
         auto: {
             format: true,
         },