import * as crypto from 'crypto';
import * as fs from 'fs/promises';
import * as path from 'path';
export class EncryptionService {
private algorithm = 'aes-256-gcm';
private saltLength = 32;
private ivLength = 16;
private tagLength = 16;
private pbkdf2Iterations = 100000;
async encryptFile(filePath: string, password: string, outputPath?: string): Promise<string> {
const content = await fs.readFile(filePath);
const encrypted = await this.encrypt(content, password);
const encryptedPath = outputPath || filePath + '.encrypted';
await fs.writeFile(encryptedPath, encrypted);
return encryptedPath;
}
async decryptFile(encryptedPath: string, password: string, outputPath?: string): Promise<string> {
const encryptedContent = await fs.readFile(encryptedPath);
const decrypted = await this.decrypt(encryptedContent, password);
const decryptedPath = outputPath || encryptedPath.replace('.encrypted', '');
await fs.writeFile(decryptedPath, decrypted);
return decryptedPath;
}
private async encrypt(data: Buffer, password: string): Promise<Buffer> {
// Generate salt
const salt = crypto.randomBytes(this.saltLength);
// Derive key from password
const key = await this.deriveKey(password, salt);
// Generate IV
const iv = crypto.randomBytes(this.ivLength);
// Create cipher
const cipher = crypto.createCipheriv(this.algorithm, key, iv);
// Encrypt data
const encrypted = Buffer.concat([
cipher.update(data),
cipher.final()
]);
// Get auth tag
const authTag = (cipher as any).getAuthTag();
// Combine salt, iv, authTag, and encrypted data
return Buffer.concat([
salt,
iv,
authTag,
encrypted
]);
}
private async decrypt(encryptedData: Buffer, password: string): Promise<Buffer> {
// Extract components
const salt = encryptedData.slice(0, this.saltLength);
const iv = encryptedData.slice(this.saltLength, this.saltLength + this.ivLength);
const authTag = encryptedData.slice(
this.saltLength + this.ivLength,
this.saltLength + this.ivLength + this.tagLength
);
const encrypted = encryptedData.slice(this.saltLength + this.ivLength + this.tagLength);
// Derive key from password
const key = await this.deriveKey(password, salt);
// Create decipher
const decipher = crypto.createDecipheriv(this.algorithm, key, iv);
(decipher as any).setAuthTag(authTag);
// Decrypt data
try {
const decrypted = Buffer.concat([
decipher.update(encrypted),
decipher.final()
]);
return decrypted;
} catch (error) {
throw new Error('Decryption failed. Invalid password or corrupted data.');
}
}
private deriveKey(password: string, salt: Buffer): Promise<Buffer> {
return new Promise((resolve, reject) => {
crypto.pbkdf2(password, salt, this.pbkdf2Iterations, 32, 'sha256', (err, derivedKey) => {
if (err) reject(err);
else resolve(derivedKey);
});
});
}
async generateHash(filePath: string): Promise<string> {
const content = await fs.readFile(filePath);
return crypto.createHash('sha256').update(content).digest('hex');
}
}
