← All Services
📖 2 min read 586 words
BACKEND

🔐 API Security

Building authentication systems that are secure AND usable

⏱️ 8+ Years
📦 20+ Projects
✓ Available for new projects
Experience at: Anaqua• Virtulab• Flowrite• ActivePrime• OPERR

🎯 What I Offer

Authentication System Design

Design and implement secure authentication for web and mobile apps.

Deliverables
  • JWT/session-based auth
  • OAuth 2.0 flows
  • Social login integration
  • Multi-factor authentication
  • Password policies

Enterprise SSO

Implement SSO for enterprise customers using SAML and OIDC.

Deliverables
  • SAML 2.0 integration
  • OpenID Connect
  • Identity provider setup
  • Just-in-time provisioning
  • Enterprise onboarding

API Security Hardening

Secure your APIs against common attacks and vulnerabilities.

Deliverables
  • Input validation
  • Rate limiting
  • API key management
  • CORS configuration
  • Security headers

🔧 Technical Deep Dive

Authentication Patterns

Different contexts need different approaches:

Session-based (Traditional Web):

  • Server stores session state
  • Cookie-based tokens
  • Good for server-rendered apps

JWT (APIs, SPAs, Mobile):

  • Stateless tokens
  • Self-contained claims
  • Scale horizontally

OAuth 2.0 (Third-party access):

  • Delegated authorization
  • Scoped permissions
  • Refresh token flow
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16

from fastapi import Depends, HTTPException
from jose import jwt, JWTError

def get_current_user(token: str = Depends(oauth2_scheme)):
    try:
        payload = jwt.decode(
            token, 
            SECRET_KEY, 
            algorithms=[ALGORITHM]
        )
        user_id = payload.get("sub")
        if user_id is None:
            raise HTTPException(status_code=401)
        return user_id
    except JWTError:
        raise HTTPException(status_code=401)

Enterprise SSO Implementation

For enterprise customers requiring SSO:

SAML 2.0:

  • Industry standard for enterprise
  • Works with Okta, Azure AD, OneLogin
  • Complex but well-supported

OpenID Connect:

  • Modern OAuth 2.0 extension
  • Easier implementation
  • Growing enterprise adoption

Key considerations:

  • Just-in-time user provisioning
  • Attribute mapping
  • Group/role synchronization
  • Session management

📋 Details & Resources

Authentication Architecture

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30

┌─────────────────────────────────────────────────────────────┐
│                    Client Applications                       │
│              (Web, Mobile, Third-party)                     │
└─────────────────────────────────────────────────────────────┘
                              │
                              ▼
┌─────────────────────────────────────────────────────────────┐
│                    API Gateway                               │
│     (Rate limiting, CORS, Security headers)                 │
└─────────────────────────────────────────────────────────────┘
                              │
                              ▼
┌─────────────────────────────────────────────────────────────┐
│                Authentication Layer                          │
│  ┌────────────┐  ┌────────────┐  ┌────────────┐            │
│  │   JWT      │  │   OAuth    │  │   SSO      │            │
│  │ Validation │  │   Server   │  │ (SAML/OIDC)│            │
│  └────────────┘  └────────────┘  └────────────┘            │
└─────────────────────────────────────────────────────────────┘
                              │
                              ▼
┌─────────────────────────────────────────────────────────────┐
│                Authorization Layer                           │
│           (RBAC, Permissions, Tenant isolation)             │
└─────────────────────────────────────────────────────────────┘
                              │
                              ▼
┌─────────────────────────────────────────────────────────────┐
│                    Protected Resources                       │
└─────────────────────────────────────────────────────────────┘

JWT Implementation

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33

from datetime import datetime, timedelta
from jose import jwt
from passlib.context import CryptContext

pwd_context = CryptContext(schemes=["bcrypt"])

class AuthService:
    def create_access_token(
        self, 
        user_id: str, 
        expires_delta: timedelta = timedelta(hours=1)
    ) -> str:
        payload = {
            "sub": user_id,
            "exp": datetime.utcnow() + expires_delta,
            "iat": datetime.utcnow(),
            "type": "access"
        }
        return jwt.encode(payload, SECRET_KEY, algorithm="HS256")
    
    def create_refresh_token(self, user_id: str) -> str:
        payload = {
            "sub": user_id,
            "exp": datetime.utcnow() + timedelta(days=30),
            "type": "refresh"
        }
        return jwt.encode(payload, REFRESH_SECRET, algorithm="HS256")
    
    def verify_password(self, plain: str, hashed: str) -> bool:
        return pwd_context.verify(plain, hashed)
    
    def hash_password(self, password: str) -> str:
        return pwd_context.hash(password)

Security Checklist

Security MeasurePurposeImplementation
HTTPS OnlyEncrypt transitTLS 1.3
Password HashingProtect credentialsbcrypt/argon2
Rate LimitingPrevent brute forceToken bucket
Input ValidationPrevent injectionPydantic/schemas
CORSControl cross-originAllowlist
Security HeadersBrowser protectionCSP, HSTS, etc.
Audit LoggingTrack accessAll auth events

OAuth 2.0 Flows

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25

from authlib.integrations.starlette_client import OAuth

oauth = OAuth()

# Configure providers
oauth.register(
    name='google',
    client_id=GOOGLE_CLIENT_ID,
    client_secret=GOOGLE_CLIENT_SECRET,
    authorize_url='https://accounts.google.com/o/oauth2/auth',
    access_token_url='https://oauth2.googleapis.com/token',
    client_kwargs={'scope': 'openid email profile'}
)

@app.get('/auth/google')
async def google_login(request: Request):
    redirect_uri = request.url_for('google_callback')
    return await oauth.google.authorize_redirect(request, redirect_uri)

@app.get('/auth/google/callback')
async def google_callback(request: Request):
    token = await oauth.google.authorize_access_token(request)
    user_info = token.get('userinfo')
    # Create or update user, issue JWT
    return create_session(user_info)

Frequently Asked Questions

What is API security?

API security involves protecting APIs from unauthorized access, abuse, and attacks. This includes: authentication (JWT, OAuth), authorization, rate limiting, input validation, encryption, and protection against common attacks (injection, BOLA, etc.).

How much does API security consulting cost?

API security development typically costs $120-180 per hour. A security review starts around $5,000-10,000, while thorough security implementation with OAuth, rate limiting, and monitoring ranges from $20,000-50,000+.

JWT vs OAuth vs API keys: which should I use?

Use API keys for: simple machine-to-machine auth, internal services. Use JWT for: stateless authentication, mobile apps. Use OAuth 2.0 for: third-party integrations, delegated authorization. Many systems combine these for different use cases.

What are common API security vulnerabilities?

OWASP API Top 10 includes: Broken Object Level Authorization (BOLA), broken authentication, excessive data exposure, lack of rate limiting, and injection attacks. I audit for these and implement proper controls.

How do you implement rate limiting?

I implement: per-user and per-IP limits, sliding window algorithms, tiered limits for different user types, graceful degradation, and proper 429 responses. Rate limiting prevents abuse and protects infrastructure.

Experience:

Related Technologies: REST APIs, FastAPI, Python, SaaS Development

💼 Real-World Results

Enterprise AI Platform Security

Anaqua
Challenge

Secure enterprise AI platform handling sensitive IP data with SSO requirements.

Solution

Implemented multi-layer security: JWT for API auth, SAML SSO for enterprise clients, role-based access control, thorough audit logging.

Result

Enterprise-grade security enabling Fortune 500 client adoption.

EdTech Platform Authentication

Virtulab
Challenge

Build complete authentication system for EdTech platform including MFA.

Solution

Designed auth system with email/password, social login, MFA with PingID, and API keys for integrations.

Result

Secure platform meeting enterprise education requirements.

SaaS Multi-tenant Security

Flowrite
Challenge

Secure multi-tenant SaaS with user isolation and API access.

Solution

JWT-based auth with tenant context, API key system for integrations, OAuth for third-party access.

Result

Scalable security supporting 100K+ users.

⚡ Why Work With Me

  • ✓ Enterprise SSO experience (SAML, OIDC)
  • ✓ Multi-tenant security for SaaS
  • ✓ Compliance experience (SOC 2 contexts)
  • ✓ Full implementation, design to deployment
  • ✓ Security without sacrificing UX

Secure Your Application

Within 24 hours

📅 Schedule a Call 📧 Send Email