secret-scanning

What this skill does

# Secret Scanning

This skill provides procedural guidance for configuring GitHub secret scanning — detecting leaked credentials, preventing secret pushes, defining custom patterns, and managing alerts.

## When to Use This Skill

Use this skill when the request involves:

- Enabling or configuring secret scanning for a repository or organization
- Setting up push protection to block secrets before they reach the repository
- Defining custom secret patterns with regular expressions
- Resolving a blocked push from the command line
- Triaging, dismissing, or remediating secret scanning alerts
- Configuring delegated bypass for push protection
- Excluding directories from secret scanning via `secret_scanning.yml`
- Understanding alert types (user, partner, push protection)
- Enabling validity checks or extended metadata checks
- Scanning local code changes for secrets before committing (via MCP / AI coding agent) — see the **Pre-Commit Scanning via AI Coding Agents** section below for the recommended plugin

## How Secret Scanning Works

Secret scanning automatically detects exposed credentials across:

- Entire Git history on all branches
- Issue descriptions, comments, and titles (open and closed)
- Pull request titles, descriptions, and comments
- GitHub Discussions titles, descriptions, and comments
- Wikis and secret gists

### Availability

| Repository Type | Availability |
|---|---|
| Public repos | Automatic, free |
| Private/internal (org-owned) | Requires GitHub Secret Protection on Team/Enterprise Cloud |
| User-owned | Enterprise Cloud with Enterprise Managed Users |

## Core Workflow — Enable Secret Scanning

### Step 1: Enable Secret Protection

1. Navigate to repository **Settings** → **Advanced Security**
2. Click **Enable** next to "Secret Protection"
3. Confirm by clicking **Enable Secret Protection**

For organizations, use security configurations to enable at scale:
- Settings → Advanced Security → Global settings → Security configurations

### Step 2: Enable Push Protection

Push protection blocks secrets during the push process — before they reach the repository.

1. Navigate to repository **Settings** → **Advanced Security**
2. Enable "Push protection" under Secret Protection

Push protection blocks secrets in:
- Command line pushes
- GitHub UI commits
- File uploads
- REST API requests
- REST API content creation endpoints

### Step 3: Configure Exclusions (Optional)

Create `.github/secret_scanning.yml` to auto-close alerts for specific directories:

```yaml
paths-ignore:
  - "docs/**"
  - "test/fixtures/**"
  - "**/*.example"
```

**Limits:**
- Maximum 1,000 entries in `paths-ignore`
- File must be under 1 MB
- Excluded paths also skip push protection checks

**Best practices:**
- Be as specific as possible with exclusion paths
- Add comments explaining why each path is excluded
- Review exclusions periodically — remove stale entries
- Inform the security team about exclusions

### Step 4: Enable Additional Features (Optional)

**Non-provider patterns** — detect private keys, connection strings, generic API keys:
- Settings → Advanced Security → enable "Scan for non-provider patterns"

**AI-powered generic secret detection** — uses Copilot to detect unstructured secrets like passwords:
- Settings → Advanced Security → enable "Use AI detection"

**Validity checks** — verify if detected secrets are still active:
- Settings → Advanced Security → enable "Validity checks"
- GitHub periodically tests detected credentials against provider APIs
- Status shown in alert: `active`, `inactive`, or `unknown`

**Extended metadata checks** — additional context about who owns a secret:
- Requires validity checks to be enabled first
- Helps prioritize remediation and identify responsible teams

## Core Workflow — Resolve Blocked Pushes

When push protection blocks a push from the command line:

### Option A: Remove the Secret

**If the secret is in the latest commit:**
```bash
# Remove the secret from the file
# Then amend the commit
git commit --amend --all
git push
```

**If the secret is in an earlier commit:**
```bash
# Find the earliest commit containing the secret
git log

# Start interactive rebase before that commit
git rebase -i <COMMIT-ID>~1

# Change 'pick' to 'edit' for the offending commit
# Remove the secret, then:
git add .
git commit --amend
git rebase --continue
git push
```

### Option B: Bypass Push Protection

1. Visit the URL returned in the push error message (as the same user)
2. Select a bypass reason:
   - **It's used in tests** — alert created and auto-closed
   - **It's a false positive** — alert created and auto-closed
   - **I'll fix it later** — open alert created
3. Click **Allow me to push this secret**
4. Re-push within 3 hours

### Option C: Request Bypass Privileges

If delegated bypass is enabled and you lack bypass privileges:
1. Visit the URL from the push error
2. Add a comment explaining why the secret is safe
3. Click **Submit request**
4. Wait for email notification of approval/denial
5. If approved, push the commit; if denied, remove the secret

> For detailed bypass and delegated bypass workflows, search `references/push-protection.md`.

## Custom Patterns

Define organization-specific secret patterns using regular expressions.

### Quick Setup

1. Settings → Advanced Security → Custom patterns → **New pattern**
2. Enter pattern name and regex for secret format
3. Add a sample test string
4. Click **Save and dry run** to test (up to 1,000 results)
5. Review results for false positives
6. Click **Publish pattern**
7. Optionally enable push protection for the pattern

### Scopes

Custom patterns can be defined at:
- **Repository level** — applies to that repo only
- **Organization level** — applies to all repos with secret scanning enabled
- **Enterprise level** — applies across all organizations

### Copilot-Assisted Pattern Generation

Use Copilot secret scanning to generate regex from a text description of the secret type, including optional example strings.

> For detailed custom pattern configuration, search `references/custom-patterns.md`.

## Alert Management

### Alert Types

| Type | Description | Visibility |
|---|---|---|
| **User alerts** | Secrets found in repository | Security tab |
| **Push protection alerts** | Secrets pushed via bypass | Security tab (filter: `bypassed: true`) |
| **Partner alerts** | Secrets reported to provider | Not shown in repo (provider-only) |

### Alert Lists

- **Default alerts** — supported provider patterns and custom patterns
- **Generic alerts** — non-provider patterns and AI-detected secrets (limited to 5,000 per repo)

### Remediation Priority

1. **Rotate the credential immediately** — this is the critical action
2. Review the alert for context (location, commit, author)
3. Check validity status: `active` (urgent), `inactive` (lower priority), `unknown`
4. Remove from Git history if needed (time-intensive, often unnecessary after rotation)

### Dismissing Alerts

Dismiss with a documented reason:
- **False positive** — detected string is not a real secret
- **Revoked** — credential has already been revoked
- **Used in tests** — secret is only in test code

> For detailed alert types, validity checks, and REST API, search `references/alerts-and-remediation.md`.

## Pre-Commit Scanning via AI Coding Agents

For scanning code changes for secrets inside an AI coding agent before committing, install the **Advanced Security plugin** which provides the `run_secret_scanning` MCP tool and a dedicated scanning skill.

**GitHub Copilot CLI:**
```bash
/plugin install advanced-security@copilot-plugins
```

**Visual Studio Code:**
- In Copilot Chat, open **Chat: Plugins** (or use `@agentPlugins`) and install the `advanced-security` plugin
- Then run `/secret-scanning` in Copilot Chat

See: [Advanced Security Plugin — Secret Scanning Skill](https://github.com/github/copilot-plugins/blob/main/plugins/advanced-security/skills/secret-scanning/SKILL.md)

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