# Testing Mobile API Authentication

> Use when tests authentication and authorization mechanisms in mobile application APIs to identify broken authentication, insecure token management, session fixation, privilege escalation, and IDOR vulnerabilities. Use when performing API security assessments against mobile app backends, testing JWT implementations, evaluating OAuth flows, or assessing session management.

- Skill: `oyi77/testing-mobile-api-authentication` (Agent Skill)
- Install (CLI): `npx skillmds add oyi77/testing-mobile-api-authentication`
- Raw SKILL.md: https://api.skillmd.com/api/skills/oyi77/testing-mobile-api-authentication/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Security
- License: Apache-2.0
- Author: oyi77 (https://skillmd.com/u/oyi77)
- Updated: 2026-09-08
- Page: https://skillmd.com/skills/oyi77/testing-mobile-api-authentication

---


# Testing Mobile Api Authentication

## Overview

Cybersecurity skill for testing mobile api authentication. Follows industry best practices and security standards.

## When to Use

**Trigger phrases:**
- "testing mobile api authentication"
- "Assessing mobile app backend API authentication during penetration tests"
- "Testing JWT token implementation for common vulnerabilities (none algorithm, wea"
- "Evaluating OAuth 2"


Use this skill when:
- Assessing mobile app backend API authentication during penetration tests
- Testing JWT token implementation for common vulnerabilities (none algorithm, weak signing)
- Evaluating OAuth 2.0 / OIDC flows in mobile applications for redirect, PKCE, and scope issues
- Testing for broken object-level authorization (BOLA/IDOR) in API endpoints

**Do not use** this skill against production APIs without explicit authorization and rate-limiting awareness.


## When NOT to Use

- When you lack proper authorization for testing
- For production systems without change management
- When the task requires legal or compliance expertise beyond technical scope


## Prerequisites

- Burp Suite or mitmproxy configured as mobile device proxy
- SSL pinning bypassed on target application (if implemented)
- Valid test account credentials for the target application
- Postman or curl for API request crafting
- jwt.io or PyJWT for JWT analysis and manipulation

## Workflow

```python
# Example: IOC detection
import re

IOC_PATTERNS = {
    "ip": r"\b(?:\d{1,3}\.){3}\d{1,3}\b",
    "domain": r"\b[a-z0-9-]+\.[a-z]{2,}\b",
    "hash_md5": r"\b[a-f0-9]{32}\b",
    "hash_sha256": r"\b[a-f0-9]{64}\b",
}

def extract_iocs(text: str) -> dict:
    return {k: re.findall(v, text) for k, v in IOC_PATTERNS.items()}
```

1. **Reconnaissance** — Gather information about the target related to mobile api authentication. Identify attack surface.
2. **Vulnerability Identification** — Enumerate potential mobile api authentication weaknesses using automated and manual techniques.
3. **Exploit Development/Selection** — Choose or develop exploits targeting identified mobile api authentication vulnerabilities.
4. **Execution** — Execute the mobile api authentication test in a controlled manner with proper authorization.
5. **Post-Exploitation** — Document the impact and extent of successful exploitation.
6. **Reporting** — Write detailed findings with reproduction steps, impact assessment, and remediation guidance.

## Tools

- **Vulnerability Scanner** — Automated weakness identification
- **Exploitation Framework** — Controlled exploitation testing
- **Reporting Tool** — Findings documentation and tracking


## Process

1. **Design** — Define interface, identify patterns, plan implementation
1. **Implement** — Write code following existing conventions, add tests
1. **Verify** — Run tests, check integration, validate behavior

## Verification

- [ ] All mobile api authentication procedures executed completely and documented
- [ ] Findings validated against multiple data sources
- [ ] False positives identified and filtered
- [ ] Results documented with evidence and timestamps
- [ ] Recommendations provided with risk-based prioritization

## Anti-Rationalization Table

| Rationalization | Reality |
|---|---|
| "We are too small to be targeted" | Automated attacks target everyone. Size does not matter. |
| "Security slows us down" | A breach slows you down 100x more. Build security in from the start. |
| "We will fix it after launch" | Vulnerabilities in production are exploited within hours. Fix before deploy. |