add some sanity check tests for generateRandomString and increase url…

… safe dictionary

packages/core/src/encryption.test.ts

@@ -1,4 +1,4 @@
-import { encrypt, decrypt } from './encryption';
+import { encrypt, decrypt, generateRandomString, generateRandomBytes } from './encryption';
 
 describe('encryption', () => {
   const testData = 'Hello, World!';
@@ -18,3 +18,28 @@ describe('encryption', () => {
     await expect(decrypt(encrypted, 'wrong-password')).rejects.toThrow();
   });
 });
+
+describe('generateRandomString', () => {
+  it("shouldn't generate the same string twice", async () => {
+    const randomString1 = await generateRandomString(15);
+    const randomString2 = await generateRandomString(15);
+    expect(randomString1).not.toBe(randomString2);
+  });
+
+  it('should generate a random string of the specified length', async () => {
+    const lengths = await generateRandomBytes(50);
+    for (const length of Array.from(new Set(lengths))) {
+      const randomString = await generateRandomString(length);
+      expect(randomString.length).toBe(length);
+    }
+  });
+
+  it('should generate all possible characters over time', async () => {
+    const dictionary =
+      'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*()_+-=[]{}|;:,.<>?';
+    const sample = await generateRandomString(10_000, dictionary);
+    for (const char of dictionary) {
+      expect(sample).toContain(char);
+    }
+  });
+});

packages/core/src/encryption.ts

@@ -63,12 +63,14 @@ export async function generateRandomHexString(length: number): Promise<string> {
     .join('');
 }
 
-const DEFAULT_DICTIONARY = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_';
+// https://stackoverflow.com/questions/695438/what-are-the-safe-characters-for-making-urls
+export const URL_SAFE_DICTIONARY = `ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_~`;
+
 // The following implementation guarantees uniformly distributed cryptographically random
 // string generation for any dictionary input length as described by https://arxiv.org/pdf/1304.1916
 export async function generateRandomString(
   length: number,
-  dictionary: string = DEFAULT_DICTIONARY,
+  dictionary: string = URL_SAFE_DICTIONARY,
 ): Promise<string> {
   const dictionaryLength = dictionary.length;
   const maxValid = Math.floor(256 / dictionaryLength) * dictionaryLength - 1;