detecting-secrets

Secret Patterns

Look for these categories of hardcoded secrets in code:

High-Confidence Patterns

Type	Example Patterns
API Keys	AKIA[0-9A-Z]{16} (AWS), AIza[0-9A-Za-z_-]{35} (Google), strings assigned to variables named *apiKey*, *api_key*
Connection Strings	Server=...;Password=..., mongodb://user:pass@host, postgres://user:pass@host
Private Keys	-----BEGIN RSA PRIVATE KEY-----, -----BEGIN OPENSSH PRIVATE KEY-----
Tokens	ghp_[A-Za-z0-9]{36} (GitHub PAT), xoxb- (Slack bot), sk- (OpenAI)
Passwords	Values assigned to variables named *password*, *passwd*, *secret*, *credential*
Certificates	PFX/P12 files with embedded passwords, PEM files with private keys

Lower-Confidence Patterns (Require Context)

• Base64-encoded strings in configuration (may be encrypted or may be cleartext secrets)
• JWT tokens (may be test tokens or production tokens)
• Hex strings of 32+ characters (may be encryption keys or hashes)
• URLs with embedded credentials (https://user:pass@host)

Context-Aware Detection

Distinguish real secrets from false positives. Not every pattern match indicates an actual secret — consider context:

Test Fixtures and Mock Data

// NOT a real secret — test fixture with obvious fake value
var testApiKey = "test-api-key-not-real-12345";
var mockPassword = "P@ssword123"; // Used only in unit tests

// REAL secret — production-looking value in non-test code
var apiKey = "sk-proj-abc123def456ghi789jkl012mno345pqr678stu901vwx";

Decision criteria:

• Is it in a test directory (**/test/**, **/tests/**, **/*.Test/**)?
• Does the value contain obvious placeholder text ("test", "fake", "mock", "example", "placeholder")?
• Is the value used in assertions or mock setups?

Example and Placeholder Values

// NOT a real secret — documented example
{
  "apiKey": "YOUR_API_KEY_HERE"
}

// REAL secret — actual value in config
{
  "apiKey": "sk-proj-abc123def456ghi789jkl012mno345pqr678stu901vwx"
}

Encrypted or Hashed Values

• Hashed passwords (bcrypt $2b$, argon2 $argon2id$) are NOT secrets — they're properly stored
• Encrypted values with proper key management are NOT secrets in the same way
• But the encryption KEY itself, if hardcoded, IS a secret

Common Hiding Spots

Search these locations when auditing for secrets:

Location	What to Look For
appsettings.json / appsettings.Development.json	Connection strings, API keys, service credentials
.env / .env.local	Environment variable definitions with real values
web.config / app.config	Machine keys, connection strings
docker-compose.yml / Dockerfile	ENV directives with credentials, build args with secrets
CI/CD files (.github/workflows/*.yml)	Inline secrets instead of ${{ secrets.* }} references
Test seed scripts / migration files	Database passwords, service account credentials
Comments and TODO notes	"Temporary" credentials left in comments
Default parameter values	function connect(password = "admin123")
Constants files	Centralized credential definitions

GitHub Secret Scanning Integration

# List all secret scanning alerts
gh api /repos/{owner}/{repo}/secret-scanning/alerts --jq '.[] | {number, state, secret_type, secret_type_display_name, created_at, push_protection_bypassed}'

# Get details for a specific alert
gh api /repos/{owner}/{repo}/secret-scanning/alerts/{alert_number}

# List alerts that bypassed push protection
gh api "/repos/{owner}/{repo}/secret-scanning/alerts?state=open" --jq '.[] | select(.push_protection_bypassed == true)'

Push protection prevents commits containing detected secrets from being pushed. When someone bypasses push protection, the alert is flagged — review these with extra scrutiny.

Remediation Workflow

When a secret is found in code, follow this sequence:

1. Rotate Immediately

Assume any committed secret is compromised. Even if the repo is private, the secret may have been cached, logged, or accessed by CI/CD systems.

• Revoke the existing credential
• Generate a new credential
• Update the credential wherever it's used (services, deployments)

2. Remove from Code

Replace the hardcoded secret with a secure reference:

// WRONG — hardcoded secret
var connectionString = "Server=prod.db;Password=s3cr3t!";

// CORRECT — environment variable
var connectionString = Environment.GetEnvironmentVariable("DB_CONNECTION_STRING");

// CORRECT — Azure Key Vault (Bitwarden's approach)
var connectionString = await keyVaultClient.GetSecretAsync("db-connection-string");

3. Remove from Git History (If Needed)

If the secret was committed to a public repo or a repo that will become public:

# Using git filter-repo (preferred over filter-branch)
git filter-repo --path-glob '*.json' --replace-text expressions.txt

# expressions.txt format:
# literal:the-secret-value==>REDACTED

Warning: Rewriting git history is destructive and affects all collaborators. Only do this when the secret was exposed in a public or soon-to-be-public repository.

4. Prevent Recurrence

• Add patterns to .gitignore for files that should never be committed (.env, *.pfx, appsettings.Development.json)
• Enable GitHub push protection for the repository
• Use secret scanning custom patterns for organization-specific secret formats

Secure Alternatives

Bitwarden uses Azure Key Vault for secrets management, provisioned by the BRE team:

Instead Of	Use
Hardcoded connection strings	Azure Key Vault secrets
API keys in config files	Environment variables set at deployment
Certificates in source	Azure Key Vault certificates
Shared team credentials in code	Managed identities (Azure)
Secrets in CI/CD workflow files	GitHub Actions secrets (${{ secrets.NAME }})

For local development, use user-secrets or .env files that are .gitignored — never commit them.

Critical Rules

• Assume any committed secret is compromised. Always rotate, even if the repo is private. No exceptions.
• Never suppress secret scanning alerts without rotation. Dismissing an alert doesn't make the exposure go away.
• Validation, not just detection. When a potential secret is found, verify it's real before raising an alarm. Check if it's a test value, placeholder, or encrypted content.
• Check the full commit history. A secret removed in the latest commit may still exist in git history. Use git log -p -S "secret-pattern" to search history.
• Bitwarden uses Azure Key Vault for secrets management. If a new secret needs to be stored, work with BRE to provision vault access for the repository.