Get Basic Auth username and password in Go

basic_auth.go

// GetBasicAuth parses the username and password from an HTTP request Basic Authorization header.
// See RFC 2617.
func GetBasicAuth(r *http.Request) (username, password string, err error) {
	// Get the Authorization header.
	authHeader := r.Header.Get("Authorization")
	if authHeader == "" {
		return "", "", errors.New("authorization header was not provided")
	}

	// Check the Authorization type is "Basic"
	authComponents := strings.Split(authHeader, " ")
	if len(authComponents) != 2 {
		return "", "", errors.New("authorization header is poorly formatted")
	}
	if authComponents[0] != "Basic" {
		return "", "", errors.New("authorization type Basic was expected")
	}

	// Base64 Decode the user-pass string.
	decoded, err := base64.StdEncoding.DecodeString(authComponents[1])
	if err != nil {
		return "", "", err
	}

	// Split apart the username and password.
	userPassComponents := strings.Split(string(decoded), ":")
	if len(userPassComponents) != 2 {
		return "", "", errors.New("authorization header is poorly formatted")
	}

	username = userPassComponents[0]
	password = userPassComponents[1]

	return username, password, nil
}