go back to bs58 and use other base64 decoder

as base-x isn't meant for base64

package.json

@@ -49,7 +49,8 @@
   "dependencies": {
     "aes-js": "^3.1.2",
     "another-json": "^0.2.0",
-    "base-x": "^3.0.8",
+    "base64-arraybuffer": "^0.2.0",
+    "bs58": "^4.0.1",
     "olm": "https://packages.matrix.org/npm/olm/olm-3.1.4.tgz"
   }
 }

scripts/post-install.mjs

@@ -75,11 +75,17 @@ async function populateLib() {
         path.join(modulesDir, 'another-json/another-json.js'),
         path.join(libDir, "another-json/index.js")
     );
-    // transpile base-x to esm
+    // transpile bs58 to esm
-    await fs.mkdir(path.join(libDir, "base-x/"));
+    await fs.mkdir(path.join(libDir, "bs58/"));
     await commonjsToESM(
-        path.join(modulesDir, 'base-x/src/index.js'),
+        path.join(modulesDir, 'bs58/index.js'),
-        path.join(libDir, "base-x/index.js")
+        path.join(libDir, "bs58/index.js")
+    );
+    // transpile base64-arraybuffer to esm
+    await fs.mkdir(path.join(libDir, "base64-arraybuffer/"));
+    await commonjsToESM(
+        path.join(modulesDir, 'base64-arraybuffer/lib/base64-arraybuffer.js'),
+        path.join(libDir, "base64-arraybuffer/index.js")
     );
     // transpile aesjs to esm
     await fs.mkdir(path.join(libDir, "aes-js/"));
@@ -87,7 +93,6 @@ async function populateLib() {
         path.join(modulesDir, 'aes-js/index.js'),
         path.join(libDir, "aes-js/index.js")
     );
-    
 }
 
 populateLib();

src/matrix/e2ee/megolm/SessionBackup.js

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {base64} from "../../utils/base-encoding.js";
+import base64 from "../../../../lib/base64-arraybuffer/index.js";
 
 export class SessionBackup {
     constructor({backupInfo, decryption, hsApi}) {
@@ -40,7 +40,7 @@ export class SessionBackup {
     static async fromSecretStorage({olm, secretStorage, hsApi, txn}) {
         const base64PrivateKey = await secretStorage.readSecret("m.megolm_backup.v1", txn);
         if (base64PrivateKey) {
-            const privateKey = base64.decode(base64PrivateKey);
+            const privateKey = new Uint8Array(base64.decode(base64PrivateKey));
             const backupInfo = await hsApi.roomKeysVersion().response();
             const expectedPubKey = backupInfo.auth_data.public_key;
             const decryption = new olm.PkDecryption();

src/matrix/ssss/SecretStorage.js

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {base64} from "../../utils/base-encoding.js";
+import base64 from "../../../lib/base64-arraybuffer/index.js";
 
 export class SecretStorage {
     constructor({key, cryptoDriver}) {

src/matrix/ssss/recoveryKey.js

@@ -13,7 +13,7 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */
-import {base58} from "../../utils/base-encoding.js";
+import bs58 from "../../../lib/bs58/index.js";
 import {Key} from "./common.js";
 
 const OLM_RECOVERY_KEY_PREFIX = [0x8B, 0x01];
@@ -25,7 +25,7 @@ const OLM_RECOVERY_KEY_PREFIX = [0x8B, 0x01];
  * @return {Key}
  */
 export function keyFromRecoveryKey(olm, keyDescription, recoveryKey) {
-    const result = base58.decode(recoveryKey.replace(/ /g, ''));
+    const result = bs58.decode(recoveryKey.replace(/ /g, ''));
 
     let parity = 0;
     for (const b of result) {

src/utils/base-encoding.js

@@ -1,25 +0,0 @@
-/*
-Copyright 2020 The Matrix.org Foundation C.I.C.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-import base from "../../lib/base-x/index.js";
-
-// Dictionaries come from https://github.com/cryptocoinjs/base-x/, MIT licenced.
-const BASE58 = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
-const BASE64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
-
-
-export const base58 = base(BASE58);
-export const base64 = base(BASE64); 

yarn.lock

@@ -945,13 +945,18 @@ balanced-match@^1.0.0:
   resolved "https://registry.yarnpkg.com/balanced-match/-/balanced-match-1.0.0.tgz#89b4d199ab2bee49de164ea02b89ce462d71b767"
   integrity sha1-ibTRmasr7kneFk6gK4nORi1xt2c=
 
-base-x@^3.0.8:
+base-x@^3.0.2:
   version "3.0.8"
   resolved "https://registry.yarnpkg.com/base-x/-/base-x-3.0.8.tgz#1e1106c2537f0162e8b52474a557ebb09000018d"
   integrity sha512-Rl/1AWP4J/zRrk54hhlxH4drNxPJXYUaKffODVI53/dAsV4t9fBxyxYKAVPU1XBHxYwOWP9h9H0hM2MVw4YfJA==
   dependencies:
     safe-buffer "^5.0.1"
 
+base64-arraybuffer@^0.2.0:
+  version "0.2.0"
+  resolved "https://registry.yarnpkg.com/base64-arraybuffer/-/base64-arraybuffer-0.2.0.tgz#4b944fac0191aa5907afe2d8c999ccc57ce80f45"
+  integrity sha512-7emyCsu1/xiBXgQZrscw/8KPRT44I4Yq9Pe6EGs3aPRTsWuggML1/1DTuZUuIaJPIm1FTDUVXl4x/yW8s0kQDQ==
+
 boolbase@~1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/boolbase/-/boolbase-1.0.0.tgz#68dff5fbe60c51eb37725ea9e3ed310dcc1e776e"
@@ -975,6 +980,13 @@ browserslist@^4.12.0, browserslist@^4.8.5:
     escalade "^3.0.2"
     node-releases "^1.1.60"
 
+bs58@^4.0.1:
+  version "4.0.1"
+  resolved "https://registry.yarnpkg.com/bs58/-/bs58-4.0.1.tgz#be161e76c354f6f788ae4071f63f34e8c4f0a42a"
+  integrity sha1-vhYedsNU9veIrkBx9j806MTwpCo=
+  dependencies:
+    base-x "^3.0.2"
+
 builtin-modules@^3.1.0:
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/builtin-modules/-/builtin-modules-3.1.0.tgz#aad97c15131eb76b65b50ef208e7584cd76a7484"