Added: TS encryption example class

web/mkdocs/docs/privacy/encryption.md

@@ -96,4 +96,83 @@ class Encryptor {
         return $result;
     }
 }
+```
+
+### TypeScript
+
+Please note, that Bun's implementation of `crypto` package is not optimized, so it is much slower than Node's implementation.
+
+```typescript
+import crypto from "crypto";
+
+class Encryptor {
+    constructor(protected readonly passphrase: string, protected readonly iterations: number = 75_000) {
+
+    }
+
+    public Decrypt(input: string): string {
+        const parts = input.split("$");
+        if (parts.length !== 5) {
+            throw new Error("Invalid encrypted text");
+        }
+
+        if (parts[1] !== "aes-256-cbc/pbkdf2-sha1") {
+            throw new Error("Unsupported algorithm");
+        }
+
+        const paramsStr = parts[2];
+        const params = this.parseParams(paramsStr);
+        if (!params.has("i")) {
+            throw new Error("Missing iteration count");
+        }
+
+        const iterations = parseInt(params.get("i")!);
+        const salt = Buffer.from(parts[3], "base64");
+        const encryptedText = Buffer.from(parts[4], "base64");
+
+        const secretKey = this.generateSecretKeyFromPassphrase(this.passphrase, salt, 32, iterations);
+        const decryptedText = this.decryptString(encryptedText, secretKey, salt);
+
+        return decryptedText.toString("utf8");
+    }
+
+    protected parseParams(params: string): Map<string, string> {
+        const keyValuePairs = params.split(",");
+
+        const result = new Map<string, string>();
+        keyValuePairs.forEach(pair => {
+            const [key, value] = pair.split("=");
+            result.set(key, value);
+        });
+        return result;
+    }
+
+    protected decryptString(input: Buffer, secretKey: Buffer, iv: Buffer): Buffer {
+        const decipher = crypto
+            .createDecipheriv("aes-256-cbc", secretKey, iv);
+        return Buffer.concat([decipher.update(input), decipher.final()]);
+    }
+
+    public Encrypt(input: string): string {
+        const salt = this.generateSalt();
+        const secretKey = this.generateSecretKeyFromPassphrase(this.passphrase, salt, 32, this.iterations);
+        const encryptedText = this.encryptString(Buffer.from(input, "utf8"), secretKey, salt);
+        return `$aes-256-cbc/pbkdf2-sha1$i=${this.iterations}$${salt.toString("base64")}$${encryptedText.toString("base64")}`;
+    }
+
+    protected encryptString(input: Buffer, secretKey: Buffer, iv: Buffer): Buffer {
+        const cypher = crypto
+            .createCipheriv("aes-256-cbc", secretKey, iv);
+
+        return Buffer.concat([cypher.update(input), cypher.final()]);
+    }
+
+    protected generateSalt(size: number = 16): Buffer {
+        return crypto.randomBytes(size);
+    }
+
+    protected generateSecretKeyFromPassphrase(passphrase: string, salt: Buffer, keyLength: number = 32, iterations: number = 75_000): Buffer {
+        return crypto.pbkdf2Sync(passphrase, salt, iterations, keyLength, "sha1");
+    }
+}
 ```