Medical Data Security: GDPR, Encryption and Compliance

# nginx.conf
server {
  listen 443 ssl http2;
  server_name keneya.com;

  ssl_certificate /etc/letsencrypt/live/keneya.com/fullchain.pem;
  ssl_certificate_key /etc/letsencrypt/live/keneya.com/privkey.pem;

  ssl_protocols TLSv1.3;
  ssl_ciphers 'ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384';
  ssl_prefer_server_ciphers on;

  add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
}

import crypto from 'crypto'

class EncryptionService {
  private algorithm = 'aes-256-gcm'
  private key: Buffer

  constructor() {
    this.key = Buffer.from(process.env.ENCRYPTION_KEY, 'hex')
  }

  encrypt(text: string): { encrypted: string; iv: string; tag: string } {
    const iv = crypto.randomBytes(16)
    const cipher = crypto.createCipheriv(this.algorithm, this.key, iv)

    let encrypted = cipher.update(text, 'utf8', 'hex')
    encrypted += cipher.final('hex')

    const tag = cipher.getAuthTag()

    return {
      encrypted,
      iv: iv.toString('hex'),
      tag: tag.toString('hex')
    }
  }

  decrypt(encrypted: string, iv: string, tag: string): string {
    const decipher = crypto.createDecipheriv(
      this.algorithm,
      this.key,
      Buffer.from(iv, 'hex')
    )

    decipher.setAuthTag(Buffer.from(tag, 'hex'))

    let decrypted = decipher.update(encrypted, 'hex', 'utf8')
    decrypted += decipher.final('utf8')

    return decrypted
  }
}

// medical-record.service.ts
async saveMedicalRecord(patientId: string, data: MedicalRecordData) {
  // Encrypt sensitive data
  const encrypted = this.encryptionService.encrypt(
    JSON.stringify({
      diagnosis: data.diagnosis,
      prescriptions: data.prescriptions,
      notes: data.notes
    })
  )

  await this.medicalRecordRepo.create({
    patientId,
    encryptedData: encrypted.encrypted,
    iv: encrypted.iv,
    tag: encrypted.tag,
    createdAt: new Date()
  })
}

async getMedicalRecord(patientId: string) {
  const record = await this.medicalRecordRepo.findByPatient(patientId)

  // Decrypt
  const decrypted = this.encryptionService.decrypt(
    record.encryptedData,
    record.iv,
    record.tag
  )

  return JSON.parse(decrypted)
}

// auth.service.ts
async login(email: string, password: string) {
  const user = await this.userRepo.findByEmail(email)

  if (!await bcrypt.compare(password, user.passwordHash)) {
    throw new UnauthorizedException('Invalid credentials')
  }

  // Access token (15min)
  const accessToken = this.jwtService.sign(
    { userId: user.id, role: user.role },
    { expiresIn: '15m' }
  )

  // Refresh token (7 days)
  const refreshToken = this.jwtService.sign(
    { userId: user.id },
    { expiresIn: '7d' }
  )

  // Save refresh token (hashed)
  await this.tokenRepo.create({
    userId: user.id,
    tokenHash: await bcrypt.hash(refreshToken, 10),
    expiresAt: new Date(Date.now() + 7 * 24 * 60 * 60 * 1000)
  })

  return { accessToken, refreshToken }
}

// guards/roles.guard.ts
@Injectable()
export class RolesGuard implements CanActivate {
  canActivate(context: ExecutionContext): boolean {
    const requiredRoles = this.reflector.get<string[]>('roles', context.getHandler())

    const request = context.switchToHttp().getRequest()
    const user = request.user

    return requiredRoles.some(role => user.role === role)
  }
}

// consultation.controller.ts
@UseGuards(JwtAuthGuard, RolesGuard)
@Roles('doctor')
@Post('prescriptions')
async createPrescription(@Body() dto: CreatePrescriptionDto) {
  // Only doctors can create prescriptions
}

// Record all sensitive actions
@Injectable()
export class AuditService {
  async log(event: AuditEvent) {
    await this.auditRepo.create({
      userId: event.userId,
      action: event.action,
      resource: event.resource,
      resourceId: event.resourceId,
      ipAddress: event.ipAddress,
      userAgent: event.userAgent,
      timestamp: new Date(),
      metadata: event.metadata
    })
  }
}

// Usage example
async viewMedicalRecord(patientId: string, doctorId: string) {
  // Record access
  await this.auditService.log({
    userId: doctorId,
    action: 'VIEW_MEDICAL_RECORD',
    resource: 'medical_record',
    resourceId: patientId,
    ipAddress: req.ip,
    userAgent: req.headers['user-agent']
  })

  return this.medicalRecordService.get(patientId)
}

@Get('my-data')
async exportMyData(@User() user: User) {
  // Compile all user data
  const data = {
    profile: await this.userService.getProfile(user.id),
    consultations: await this.consultationService.getUserConsultations(user.id),
    medicalRecords: await this.medicalRecordService.getUserRecords(user.id),
    payments: await this.paymentService.getUserPayments(user.id)
  }

  // Return as JSON
  return data
}

@Delete('delete-account')
async deleteAccount(@User() user: User) {
  // Anonymize data (not delete completely for medical history)
  await this.userService.anonymize(user.id)

  // Delete non-critical data
  await this.notificationService.deleteUserNotifications(user.id)

  // Mark account as deleted
  await this.userService.markAsDeleted(user.id)
}

interface UserConsent {
  marketing: boolean
  dataSharing: boolean
  analytics: boolean
  consentDate: Date
}

// Record consent
await this.consentService.update(user.id, {
  marketing: false,
  dataSharing: true,  // Share with doctors only
  analytics: true,
  consentDate: new Date()
})