owasp-amass/amass · error

missing username in database URI

Error message

missing username in database URI

What it means

loadDatabase requires the database URI to carry credentials; after parsing, if u.User is nil or the username part is empty, it returns this error. The library enforces authenticated connections to the graph database.

Solutions

1. Embed credentials in the URI userinfo: neo4j://user:password@host:7687/db.
2. Percent-encode special characters in the password (e.g. @ -> %40, # -> %23).
3. Verify with url.Parse that u.User.Username() is non-empty before saving the config.

Example fix

// before
"database": "neo4j://localhost:7687/mydb"
// after
"database": "neo4j://user:p%40ss@localhost:7687/mydb"

u, _ := url.Parse(dbURI)
if u.User == nil || u.User.Username() == "" {
    return errors.New("database URI must include username in userinfo")
}

if err := loadDatabase(uri); err != nil {
    if strings.Contains(err.Error(), "missing username") {
        return fmt.Errorf("add user:pass@ to URI: %w", err)
    }
}

When it happens

Trigger: A configured URI like 'neo4j://localhost:7687/db' (no userinfo) or 'neo4j://:password@host/db' (empty username) reaches loadDatabase.

Common situations: Storing credentials separately and forgetting the user:pass@ userinfo; password contains characters like @ or / that were not percent-encoded and broke parsing; config migration dropped the userinfo.

Related errors

• missing hostname in database URI
• missing scheme in database URI
• unable to parse database URI query parameters
• AddCredentials: The accountName argument is invalid
• AddCredentials: The Credentials argument is invalid

AI-assisted analysis of owasp-amass/amass@79299dce87 (2026-09-06). Data as JSON: /api/errors/f8f6b1363f9f5342. Report an issue: GitHub.

Appendix: source

Thrown at config/graphdb.go:115

	if c.GraphDBs == nil {
		c.GraphDBs = make([]*Database, 0)
	}
	c.GraphDBs = append(c.GraphDBs, db)
	return nil
}

func (c *Config) loadDatabase(dbURI string) error {
	u, err := url.Parse(dbURI)
	if err != nil {
		return err
	}
	// Check for valid scheme (database type)
	if u.Scheme == "" {
		return fmt.Errorf("missing scheme in database URI")
	}
	// Check for non-empty username
	if u.User == nil || u.User.Username() == "" {
		return fmt.Errorf("missing username in database URI")
	}
	// Check for reachable hostname
	if u.Hostname() == "" {
		return fmt.Errorf("missing hostname in database URI")
	}

	dbName := ""
	// Only get the database name if it's not empty or a single slash
	if u.Path != "" && u.Path != "/" {
		dbName = strings.TrimPrefix(u.Path, "/")
	}

	db := &Database{
		Primary:  true, // Set as primary, because it wouldn't be there otherwise.
		URL:      dbURI,
		System:   u.Scheme,
		Username: u.User.Username(),
		DBName:   dbName,

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