From dde7d9a7322ada9a9aa66d84e735e64f275bab48 Mon Sep 17 00:00:00 2001
From: fyears <hjwdhjwd@gmail.com>
Date: Fri, 31 Dec 2021 20:55:13 +0800
Subject: [PATCH] fix enc base64url doc test

---
 docs/encryption.md    | 15 ++++++++++-----
 src/misc.ts           |  8 ++++++++
 tests/encrypt.test.ts |  9 +++++----
 3 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/docs/encryption.md b/docs/encryption.md
index 8f8c488..5fb9958 100644
--- a/docs/encryption.md
+++ b/docs/encryption.md
@@ -15,15 +15,20 @@ The encryption algorithm is delibrately designed to be aligned with openssl form
    openssl enc -d -p -aes-256-cbc -pbkdf2 -iter 20000 -pass pass:somepassword -in ./sometext.txt.enc -out ./sometext.txt
    ```
 
-3. The file/directory path strings, are encrypted using openssl in binary mode and then `base32` is applied.
+3. The file/directory path strings, are encrypted using openssl in binary mode and then `base64url without padding` is applied.
    Assuming the file path is `a-folder-文件夹/a-file-文件.md`, then the following commands are equivilent:
 
    ```bash
-   # pure string encryption then base32
-   echo -n 'a-folder-文件夹/a-file-文件.md' | openssl enc -aes-256-cbc -pbkdf2 -iter 20000 -pass pass:mylongpassword | base32 -w 0
+   # prepare the functions
+   # https://unix.stackexchange.com/questions/628842
+   base64url::encode () { base64 -w0 | tr '+/' '-_' | tr -d '='; }
+   base64url::decode () { awk '{ if (length($0) % 4 == 3) print $0"="; else if (length($0) % 4 == 2) print $0"=="; else print $0; }' | tr -- '-_' '+/' | base64 -d; }
 
-   # pure string base32 then decryption
-   echo -n 'KNQWY5DFMRPV7UHRWVYFSHE2XVVVZCFN65SR7ETEKO5L6EYGXCVEPT4A2LVTW4W2ZHXWF3K22SVA562CCZ6SALARXJY6AAXXHLK5UOA=' | base32 -d -w 00 | openssl enc -d -aes-256-cbc -pbkdf2 -iter 20000 -pass pass:mylongpassword
+   # pure string encryption then base32
+   echo -n 'a-folder-文件夹/a-file-文件.md' | openssl enc -aes-256-cbc -pbkdf2 -iter 20000 -pass pass:mylongpassword | base64url::encode
+
+   # pure string base64url then decryption
+   echo -n 'U2FsdGVkX19tNkdFL5rZeHxbe7FL-Pp5mkZJkDNFJWFT6lldZlfa57j0C_cKn0I3PZ9YDvOkyoKqfF6lbn0_yg' | base64url::decode | openssl enc -d -aes-256-cbc -pbkdf2 -iter 20000 -pass pass:mylongpassword
    ```
 
 4. The directory is considered as special "0-byte" object on remote s3. So this meta infomation may be easily guessed if some third party can access the remote bucket.
diff --git a/src/misc.ts b/src/misc.ts
index 6d80b7c..c0537c3 100644
--- a/src/misc.ts
+++ b/src/misc.ts
@@ -114,6 +114,14 @@ export const base64ToBase32 = (a: string) => {
   return base32.stringify(Buffer.from(a, "base64"));
 };
 
+export const base64ToBase64url = (a: string, pad: boolean = false) => {
+  let b = a.replace(/\+/g, "-").replace(/\//g, "_");
+  if (!pad) {
+    b = b.replace(/=/g, "");
+  }
+  return b;
+};
+
 /**
  * iOS Safari could decrypt string with invalid password!
  * So we need an extra way to test the decrypted result.
diff --git a/tests/encrypt.test.ts b/tests/encrypt.test.ts
index 0bdedb1..a6415ad 100644
--- a/tests/encrypt.test.ts
+++ b/tests/encrypt.test.ts
@@ -2,12 +2,13 @@ import * as fs from "fs";
 import * as path from "path";
 import * as chai from "chai";
 import chaiAsPromised from "chai-as-promised";
-import { base64ToBase32, bufferToArrayBuffer } from "../src/misc";
+import { base64ToBase64url, bufferToArrayBuffer } from "../src/misc";
 import {
   decryptArrayBuffer,
   decryptBase32ToString,
   encryptArrayBuffer,
   encryptStringToBase32,
+  encryptStringToBase64url,
 } from "../src/encrypt";
 
 chai.use(chaiAsPromised);
@@ -52,7 +53,7 @@ describe("Encryption tests", () => {
     ).toString("utf-8");
     const password = "somepassword";
     const saltHex = "8302F586FAB491EC";
-    const enc = await encryptStringToBase32(
+    const enc = await encryptStringToBase64url(
       fileContent,
       password,
       undefined,
@@ -65,9 +66,9 @@ describe("Encryption tests", () => {
     const opensslBase64Res =
       "U2FsdGVkX1+DAvWG+rSR7BPXMnlvSSVGMdjsx7kE1CTH+28P+yAZRdDGgFWMGkMd";
     // we output base32, so we need some transformation
-    const opensslBase32Res = base64ToBase32(opensslBase64Res);
+    const opensslBase64urlRes = base64ToBase64url(opensslBase64Res);
 
-    expect(enc).equal(opensslBase32Res);
+    expect(enc).equal(opensslBase64urlRes);
   });
 
   it("should encrypt binary file and get the same result as openssl", async () => {