2nd/10_Wiki/Topics/Coding/DevSec_DAST_SAST.md

---
id: devsec-dast-sast
title: SAST / DAST / IAST — 코드 / 실행 / 통합 검사
category: Coding
status: draft
source_trust_level: B
verification_status: conceptual
created_at: 2026-05-09
updated_at: 2026-05-09
tags: [devsecops, sast, dast, security, vibe-coding]
tech_stack: { language: "Various", applicable_to: ["DevOps"] }
applied_in: []
aliases: [SAST, DAST, IAST, Semgrep, CodeQL, OWASP ZAP, security testing]
---

# SAST / DAST / IAST

> **SAST = static (코드 분석), DAST = dynamic (실행 중 검사), IAST = 통합 (실행 + agent)**. SAST 매 PR + DAST 정기 + IAST production. **Semgrep / CodeQL / Snyk Code / OWASP ZAP / Burp**.

## 📖 핵심 개념
- SAST: Source code 분석 — false positive 자주.
- DAST: 실행 → 외부 attack — false negative 자주.
- IAST: SAST + DAST + agent — 정확.
- SCA: Software Composition Analysis (의존성).

## 💻 코드 패턴

### Semgrep (SAST, OSS, modern)
```bash
# 표준 ruleset
semgrep --config=auto src/

# 특정 ruleset
semgrep --config=p/owasp-top-ten src/
semgrep --config=p/javascript src/
semgrep --config=p/typescript src/
semgrep --config=p/react src/
```

```yaml
# 자체 rule
rules:
  - id: no-eval
    pattern: eval(...)
    message: "eval() is dangerous"
    severity: ERROR
    languages: [javascript, typescript]

  - id: hardcoded-secret
    patterns:
      - pattern-regex: '(api_key|password|token)\s*=\s*["''][\w-]{20,}'
    message: "Hardcoded secret"
    severity: ERROR
```

### CodeQL (GitHub)
```yaml
# .github/workflows/codeql.yml
- uses: github/codeql-action/init@v3
  with: { languages: javascript, typescript }

- uses: github/codeql-action/analyze@v3
```

→ GitHub Advanced Security. 깊은 분석.

### Snyk Code (commercial)
```bash
snyk code test
```

→ AI 기반 false positive 적음.

### Common SAST 발견
```ts
// SQL injection
const q = `SELECT * FROM users WHERE name = '${name}'`;  // ❌

// Path traversal
const file = readFile(`/data/${userInput}`);  // ❌

// XSS
res.send(`<h1>${userInput}</h1>`);  // ❌

// SSRF
fetch(req.body.url);  // ❌

// Hardcoded secret
const API_KEY = 'sk-abc123...';  // ❌

// Insecure crypto
crypto.createHash('md5').update(password).digest('hex');  // ❌
```

### DAST — OWASP ZAP
```bash
# Quick scan
docker run -t owasp/zap2docker-stable zap-baseline.py -t https://example.com

# Full scan
docker run -v $(pwd):/zap/wrk owasp/zap2docker-stable \
  zap-full-scan.py -t https://example.com -r report.html
```

```yaml
# CI — staging 배포 후
- name: ZAP scan
  uses: zaproxy/action-baseline@v0.10.0
  with:
    target: 'https://staging.example.com'
    fail_action: false  # 자동 fail X — 검토
```

### Burp Suite (manual / advanced)
```
- Web app proxy
- 사용자 행동 capture
- Replay + 변형
- Active scan
```

→ Pen test 표준.

### Authenticated DAST
```yaml
# ZAP 가 로그인 후 검사
- name: ZAP authenticated
  run: |
    zap-cli context import context.xml
    zap-cli active-scan https://staging.example.com
```

### IAST (modern)
```
Contrast Security / Datadog ASM
- Agent 가 runtime 추적
- 실제 사용 path 만 검사
- false positive ~0
```

```ts
// Datadog
import 'dd-trace/init';
// agent 가 자동 — SAST + DAST 결합
```

### Pre-commit hook (빠른 feedback)
```yaml
# .pre-commit-config.yaml
repos:
  - repo: https://github.com/returntocorp/semgrep
    rev: v1.45.0
    hooks:
      - id: semgrep
        args: [--config=p/secrets, --error]

  - repo: https://github.com/Yelp/detect-secrets
    rev: v1.4.0
    hooks:
      - id: detect-secrets
        args: [--baseline, .secrets.baseline]
```

### Secret scanning
```bash
# Gitleaks
gitleaks detect --source . --verbose

# TruffleHog
trufflehog filesystem .

# detect-secrets
detect-secrets scan --baseline .secrets.baseline
```

→ git history 안 secret 검출.

```yaml
# GitHub
- name: Gitleaks
  uses: gitleaks/gitleaks-action@v2
```

### License scanning
```bash
license-checker --excludePackages 'MIT;Apache-2.0;ISC;BSD-3-Clause' --failOn 'GPL-3.0;AGPL-3.0'
```

### IaC scanning
```bash
# Trivy IaC
trivy config .

# Checkov
checkov -d terraform/

# Tfsec
tfsec .
```

```hcl
# 발견 예
resource "aws_s3_bucket" "data" { 
  bucket = "data"
  # ❌ encryption 없음
  # ❌ versioning 없음
  # ❌ public access block 없음
}
```

### CI 통합 — fail 정책
```yaml
- name: SAST
  run: semgrep --config=auto --error --severity ERROR src/

- name: SCA
  run: npm audit --audit-level=high

- name: Secrets
  run: gitleaks detect --no-git --source .

- name: IaC
  run: trivy config terraform/ --severity HIGH,CRITICAL --exit-code 1
```

### False positive 관리
```yaml
# .semgrepignore
src/legacy/**

# nosem comment
const x = eval(safeExpression); // nosemgrep: no-eval
```

→ Triaged false positive 만 ignore.

### SARIF (표준 format)
```yaml
- name: Semgrep
  run: semgrep --config=auto --sarif --output=results.sarif

- uses: github/codeql-action/upload-sarif@v3
  with: { sarif_file: results.sarif }
```

→ GitHub Security 탭.

### Threat modeling (위쪽)
- STRIDE / DREAD framework.
- 새 feature 마다 threat list.
- SAST / DAST 보다 먼저 — 디자인 단계.

## 🤔 의사결정 기준
| 단계 | 도구 |
|---|---|
| Pre-commit | Gitleaks / Semgrep |
| PR CI | SAST (Semgrep / CodeQL) + SCA (npm audit) + IaC (Trivy) |
| Staging | DAST (ZAP) |
| Production | IAST (Datadog) |
| Audit / pen test | Burp Suite |
| Compliance | SARIF + GitHub Security |

## ❌ 안티패턴
- **SAST 만 + DAST 없음**: business logic flaw 못 잡음.
- **DAST 만 + SAST 없음**: 코드 path 안 닿는 곳 missed.
- **모든 finding fail CI**: 노이즈. severity 기반.
- **False positive 그냥 ignore (rule 끄기)**: 실제 issue 도 놓침. inline.
- **Secret 발견 후 force push**: history 안 남음. rotate + history rewrite.
- **Production agent 끄기**: 성능 우선 — risk.
- **IaC scan 누락**: cloud misconfig 자주.

## 🤖 LLM 활용 힌트
- Semgrep + Gitleaks + Trivy IaC = OSS 좋은 baseline.
- DAST = staging schedule.
- IAST 가 modern best.
- SARIF 로 통일.

## 🔗 관련 문서
- [[Security_OWASP_Top_10_Practical]]
- [[DevSec_Container_Scanning]]
- [[DevSec_Supply_Chain]]