Identification Failures in Adonisjs with Basic Auth

Identification failures occur when an API cannot reliably distinguish one user from another. In Adonisjs combined with HTTP Basic Auth, this typically stems from how credentials are parsed, how the user identity is resolved, and how authorization decisions are made after authentication. Adonisjs does not enforce a single canonical way to handle authentication; it relies on application code or third-party packages to validate credentials and attach a user to the request context. When Basic Auth is used, the credentials are sent in the Authorization header as Basic base64(username:password). If the application fails to treat the username as a precise, case-sensitive identifier and normalizes or lowercases it before lookup, it can lead to confusion between accounts that differ only in case. This can allow an attacker to authenticate as Admin by providing admin if the lookup is not exact, bypassing intended identity boundaries.

Another common pitfall is missing or inconsistent verification of the password for the resolved user. If the code resolves a user by username but then skips password validation under certain conditions (for example, when a flag is set or when a fallback mechanism is used), it effectively downgrades the authentication to something weaker, enabling identification failures where one user is treated as another. Additionally, if the application reuses the same authenticated identity across multiple tenant or scope boundaries without validating tenant ownership, a BOLA/IDOR pattern emerges. An attacker who knows or guesses another user’s username could potentially access resources belonging to that user if the endpoint does not enforce ownership checks on the resolved identity.

Adonisjs pipelines and middleware can inadvertently contribute to identification failures if they modify the request object in ways that obscure the original identity. For example, if middleware normalizes usernames, strips whitespace inconsistently, or merges authentication data from multiple sources (e.g., Basic Auth and session), the final identity may not match what the backend expects. This inconsistency can cause authorization logic to apply the wrong permissions, leading to privilege confusion or horizontal privilege escalation. Because Basic Auth transmits credentials on every request, any mismatch in how those credentials are interpreted across routes or services increases the risk that an attacker can substitute one identity for another.

From a scanning perspective, middleBrick examines runtime behavior and spec definitions to detect identification failure risks. When Basic Auth is used, the scanner checks whether the API distinguishes between authentication and authorization, validates that usernames are compared exactly without unsafe normalization, and confirms that endpoints enforcing per-user data boundaries also validate ownership on each request. These checks map to the broader Identification and Authentication category in the OWASP API Top 10 and can intersect with BOLA/IDOR when user-specific data is accessed without verifying the requesting identity matches the resource owner.

To remediate identification failures when using HTTP Basic Auth in Adonisjs, ensure usernames are handled exactly as provided, passwords are always validated, and authorization checks explicitly verify ownership. Below are concrete code examples that demonstrate a secure approach using Adonisjs native guards and provider-based authentication.

First, define a custom auth provider or extend the default one to enforce exact username matching and proper password verification. In start/auth.ts, configure an authenticator that uses the base64(username:password) credentials safely:

import { HttpContextContract } from '@ioc:Adonis/Core/HttpContext'
import { BaseAuthProvider } from '@ioc:Adonis/Addons/Auth'

export default class CustomBasicAuthProvider extends BaseAuthProvider {
  public async authenticate(ctx: HttpContextContract) {
    const header = ctx.request.header('authorization')
    if (!header || !header.startsWith('Basic ')) {
      return null
    }
    const encoded = header.split(' ')[1]
    const decoded = Buffer.from(encoded, 'base64').toString('utf-8')
    const [username, password] = decoded.split(':')
    if (username === undefined || password === undefined) {
      return null
    }
    // Exact match on username, do not normalize case
    const user = await User.findBy('username', username)
    if (!user) {
      return null
    }
    const passwordVerified = await user.verifyPassword(password)
    return passwordVerified ? user : null
  }
}

Register this provider in start/auth.ts:

import { defineConfig } from '@ioc:Adonis/Core/Auth'
import CustomBasicAuthProvider from 'App/Providers/Auth/CustomBasicAuthProvider'

export default defineConfig({
  guard: {
    authenticator: 'customBasic'
  },
  providers: {
    customBasic: () => import('App/Providers/Auth/CustomBasicAuthProvider')
  }
})

In your route or controller, always pair authentication with explicit ownership checks to prevent BOLA/IDOR. For example, when accessing a user-specific resource, confirm that the authenticated user matches the resource owner:

import { HttpContextContract } from '@ioc:Adonis/Core/HttpContext'
import User from 'App/Models/User'

export default class UsersController {
  public async show({ params, auth }: HttpContextContract) {
    const authenticatedUser = auth.user
    if (!authenticatedUser) {
      return response.unauthorized()
    }
    const targetUser = await User.findOrFail(params.id)
    // Ensure the authenticated user is the same as the target user
    if (authenticatedUser.id !== targetUser.id) {
      return response.forbidden()
    }
    return targetUser
  }
}

Additionally, avoid optional or fallback authentication paths that might skip password checks. Always ensure that the resolved user and verified password are required conditions before granting access. Configure middleware to reject requests that cannot be authenticated rather than allowing anonymous fallbacks that blur identity boundaries.

For teams using the middleBrick CLI, you can scan your endpoints to surface identification failure risks and confirm that Basic Auth handling aligns with these patterns:

middlebrick scan https://api.example.com

The CLI produces a JSON report highlighting findings related to authentication, BOLA/IDOR, and input validation, helping you prioritize fixes for identity handling in Adonisjs applications.