socks5

type AddrSpec struct {
	AddressType byte
	FQDN        string
	IP          net.IP
	Port        int
}

type AddressRewriter interface {
	Rewrite(ctx context.Context, request *Request) (context.Context, *AddrSpec)
}

type AuthContext struct {
	// Provided auth method
	Method uint8
	// Payload provided during negotiation.
	// Keys depend on the used auth method.
	// For UserPassauth contains Username
	Payload map[string]string
}

type Authenticator interface {
	Authenticate(reader io.Reader, writer io.Writer) (*AuthContext, error)
	GetCode() uint8
}

type Config struct {
	// AuthMethods can be provided to implement custom authentication
	// By default, "auth-less" mode is enabled.
	// For password-based auth use UserPassAuthenticator.
	AuthMethods []Authenticator

	// If provided, username/password authentication is enabled,
	// by appending a UserPassAuthenticator to AuthMethods. If not provided,
	// and AUthMethods is nil, then "auth-less" mode is enabled.
	Credentials CredentialStore

	// Resolver can be provided to do custom name resolution.
	// Defaults to DNSResolver if not provided.
	Resolver NameResolver

	// Rules is provided to enable custom logic around permitting
	// various commands. If not provided, PermitAll is used.
	Rules RuleSet

	// Rewriter can be used to transparently rewrite addresses.
	// This is invoked before the RuleSet is invoked.
	// Defaults to NoRewrite.
	Rewriter AddressRewriter

	// BindIP is used for bind or udp associate
	BindIP net.IP

	// Logger can be used to provide a custom log target.
	// Defaults to stdout.
	Logger *log.Logger

	// Optional function for dialing out
	Dial func(ctx context.Context, network, addr string) (net.Conn, error)
}

type CredentialStore interface {
	Valid(user, password string) bool
}

type DNSResolver struct{}

type NameResolver interface {
	Resolve(ctx context.Context, name string) (context.Context, net.IP, error)
}

type NoAuthAuthenticator struct{}

type PermitCommand struct {
	EnableConnect   bool
	EnableBind      bool
	EnableAssociate bool
}

type Request struct {
	// Protocol version
	Version uint8
	// Requested command
	Command uint8
	// reserved header byte
	Reserved uint8
	// AuthContext provided during negotiation
	AuthContext *AuthContext
	// AddrSpec of the the network that sent the request
	RemoteAddr *AddrSpec
	// AddrSpec of the desired destination
	DestAddr *AddrSpec
	// contains filtered or unexported fields
}

type RuleSet interface {
	Allow(ctx context.Context, req *Request) (context.Context, bool)
}

type Server struct {
	// contains filtered or unexported fields
}

type StaticCredentials map[string]string

type UserPassAuthenticator struct {
	Credentials CredentialStore
}