Broken Authentication in Adonisjs with Dynamodb

Broken Authentication occurs when application functions related to authentication and session management are implemented incorrectly, allowing attackers to compromise passwords, keys, or session tokens. The combination of AdonisJS and DynamoDB can introduce specific risks if security best practices are not followed, particularly around credential storage, token handling, and access patterns.

AdonisJS is a Node.js web framework that relies on robust session and authentication libraries. When paired with DynamoDB as a persistence store for user credentials or session data, misconfigurations can lead to authentication bypass or credential leakage. For example, storing passwords without strong adaptive hashing makes offline brute-force or rainbow table attacks feasible. If DynamoDB tables storing user data are not properly isolated or encrypted, an attacker who gains read access may harvest credentials directly.

Common broken authentication patterns in this stack include:

• Using weak or no salting when hashing passwords, enabling precomputed attacks.
• Exposing user enumeration via timing differences in DynamoDB queries (e.g., returning different responses for existing vs. non-existing users).
• Storing session identifiers in predictable locations or without proper expiration, enabling session fixation or hijacking.
• Failing to enforce multi-factor authentication for privileged operations, increasing the impact of stolen credentials.
• Overly permissive IAM policies for the application’s DynamoDB access, allowing broader data access than necessary.

An attacker may exploit these issues to impersonate users, escalate privileges, or extract sensitive data. Because DynamoDB is a managed NoSQL database, developers must explicitly enforce security controls at the application and configuration layers; the service does not automatically protect against logical authentication flaws.

To remediate broken authentication when using AdonisJS with DynamoDB, apply secure coding practices for credential storage, session management, and data access. Below are concrete code examples demonstrating secure implementations.

Secure Password Hashing with AdonisJS and DynamoDB

Use bcrypt via AdonisJS provider to hash passwords before storing them in DynamoDB. Never store plaintext or weakly hashed passwords.

import { Hash } from '@ioc:Adonis/Core/Hash'
import { DateTime } from 'luxon'
import { DynamoDBClient, PutItemCommand, GetItemCommand } from '@aws-sdk/client-dynamodb'

const ddbClient = new DynamoDBClient({ region: 'us-east-1' })

export default class UsersController {
  public async register({ request, response }) {
    const { email, password } = request.body()

    // Validate input
    if (!email || !password) {
      return response.badRequest({ error: 'Missing email or password' })
    }

    // Check if user already exists (use a GSI on email for efficiency)
    const getCmd = new GetItemCommand({
      TableName: 'users',
      Key: { email: { S: email } }
    })
    const exists = await ddbClient.send(getCmd)
    if (exists.Item) {
      return response.conflict({ error: 'Email already registered' })
    }

    // Hash password with a work factor of 12
    const hashedPassword = await Hash.make(password, { rounds: 12 })

    const putCmd = new PutItemCommand({
      TableName: 'users',
      Item: {
        email: { S: email },
        password_hash: { S: hashedPassword },
        created_at: { S: DateTime.local().toISO() },
        mfa_enabled: { BOOL: false }
      }
    })
    await ddbClient.send(putCmd)

    return response.created({ message: 'User created' })
  }
}

Mitigating User Enumeration

Use a consistent response time and message for authentication failures to prevent attackers from guessing valid usernames or emails.

import { Hash } from '@ioc:Adonis/Core/Hash'
import { DynamoDBClient, GetItemCommand, UpdateItemCommand } from '@aws-sdk/client-dynamodb'

export async function authenticate(email: string, password: string) {
  const ddb = new DynamoDBClient({ region: 'us-east-1' })

  // Always perform a dummy hash to keep timing consistent
  const dummyHash = await Hash.make('dummy_password', { rounds: 12 })

  const cmd = new GetItemCommand({
    TableName: 'users',
    Key: { email: { S: email } },
    ProjectionExpression: 'password_hash,mfa_enabled'
  })
  const result = await ddb.send(cmd)

  const storedHash = result.Item?.password_hash?.S
  if (storedHash && await Hash.verify(password, storedHash)) {
    // Proceed with MFA or session creation
    return { authenticated: true, mfa_enabled: result.Item.mfa_enabled?.BOOL }
  }

  // Always run the dummy verification to prevent timing leaks
  await Hash.verify('dummy_password', dummyHash)
  return { authenticated: false }
}

Session Management Best Practices

Store session metadata in DynamoDB with short TTL and avoid embedding sensitive data. Use signed, HttpOnly cookies for session identifiers.

import { uuid } from '@ioc:Adonis/Core/Helpers'
import { DynamoDBClient, PutItemCommand } from '@aws-sdk/client-dynamodb'

export async function createSession(userId: string) {
  const sessionId = uuid()
  const expiresAt = Date.now() + 7 * 24 * 60 * 60 * 1000 // 7 days

  const ddb = new DynamoDBClient({ region: 'us-east-1' })
  await ddb.send(new PutItemCommand({
    TableName: 'sessions',
    Item: {
      session_id: { S: sessionId },
      user_id: { S: userId },
      expires_at: { N: String(expiresAt) },
      created_at: { S: new Date().toISOString() }
    },
    // Configure TTL in DynamoDB console or via SDK for automatic cleanup
  }))

  return sessionId
}

Least-Privilege IAM Policies

Ensure the application’s IAM role or user has minimal permissions on DynamoDB tables, allowing only required actions on specific resources.

# Example IAM policy snippet (JSON)
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "dynamodb:GetItem",
        "dynamodb:Query"
      ],
      "Resource": "arn:aws:dynamodb:us-east-1:123456789012:table/users"
    },
    {
      "Effect": "Allow",
      "Action": [
        "dynamodb:PutItem"
      ],
      "Resource": "arn:aws:dynamodb:us-east-1:123456789012:table/sessions"
    }
  ]
}

By implementing these patterns, you reduce the risk of broken authentication and ensure that DynamoDB access is tightly controlled and predictable.