Writer abstraction to write scan resources in different formats (plai…

…n, JSON, MD...)

internal/config.go

@@ -0,0 +1,220 @@
+package scan
+
+import (
+	"encoding/json"
+	"io"
+	"reflect"
+)
+
+// Never obfuscate the Config type.
+var _ = reflect.TypeOf(Config{})
+
+// Config defines the configuration used by the scanner to perform a [scan].
+// It includes options to control the scanner's behavior, such as the rate of
+// requests per second, the concurrency level, and the output format.
+type Config struct {
+	RPS             int `default:"100"`
+	Concurrency     int `default:"100"`
+	Version         string
+	SaveOnStop      bool
+	InMemory        bool
+	BlindHost       string
+	BlindHostKey    string
+	EmailAddress    bool
+	CustomTokens    map[string]string
+	PayloadStrategy PayloadStrategy
+
+	Silent           bool
+	StreamErrors     bool
+	StreamMatches    bool
+	ShowResponses    bool
+	ShowErrors       bool
+	ShowAll          bool
+	ShowAllRequests  bool
+	ShowAllResponses bool
+
+	OutPath   string
+	OutFormat string
+}
+
+// Clone returns a deep copy of the [Config] instance.
+func (c Config) Clone() Config {
+	clonedTokens := make(map[string]string)
+	for key, value := range c.CustomTokens {
+		clonedTokens[key] = value
+	}
+
+	return Config{
+		RPS:             c.RPS,
+		Concurrency:     c.Concurrency,
+		Version:         c.Version,
+		SaveOnStop:      c.SaveOnStop,
+		InMemory:        c.InMemory,
+		BlindHost:       c.BlindHost,
+		BlindHostKey:    c.BlindHostKey,
+		EmailAddress:    c.EmailAddress,
+		CustomTokens:    clonedTokens,
+		PayloadStrategy: c.PayloadStrategy,
+
+		Silent:           c.Silent,
+		StreamErrors:     c.StreamErrors,
+		StreamMatches:    c.StreamMatches,
+		ShowResponses:    c.ShowResponses,
+		ShowErrors:       c.ShowErrors,
+		ShowAll:          c.ShowAll,
+		ShowAllRequests:  c.ShowAllRequests,
+		ShowAllResponses: c.ShowAllResponses,
+
+		OutPath:   c.OutPath,
+		OutFormat: c.OutFormat,
+	}
+}
+
+// BlindHostConfigured returns whether the blind host and its key are configured.
+func (c Config) BlindHostConfigured() bool {
+	return len(c.BlindHost) > 0 && len(c.BlindHostKey) > 0
+}
+
+// CfgOption is a function that modifies a [Config] instance.
+// See [WithRPS] and [WithConcurrency] as examples.
+type CfgOption func(*Config)
+
+// WithRPS sets the rate of requests per second.
+func WithRPS(rps int) CfgOption {
+	return func(cfg *Config) {
+		cfg.RPS = rps
+	}
+}
+
+// WithConcurrency sets the concurrency level.
+func WithConcurrency(concurrency int) CfgOption {
+	return func(cfg *Config) {
+		cfg.Concurrency = concurrency
+	}
+}
+
+// WithBlindHost sets the blind host.
+func WithBlindHost(blindHost string) CfgOption {
+	return func(cfg *Config) {
+		cfg.BlindHost = blindHost
+	}
+}
+
+// WithBlindHostKey sets the blind host key.
+func WithBlindHostKey(blindHostKey string) CfgOption {
+	return func(cfg *Config) {
+		cfg.BlindHostKey = blindHostKey
+	}
+}
+
+// WithCustomTokens sets the custom tokens.
+func WithCustomTokens(customTokens map[string]string) CfgOption {
+	return func(cfg *Config) {
+		cfg.CustomTokens = customTokens
+	}
+}
+
+// WithPayloadStrategy sets the payload strategy.
+func WithPayloadStrategy(ps string) CfgOption {
+	return func(cfg *Config) {
+		// Attention, please.
+		// PayloadStrategyFromString defaults to
+		// PayloadStrategyAll (performance implications).
+		cfg.PayloadStrategy = PayloadStrategyFromString(ps)
+	}
+}
+
+// CfgOptionsFromJSON parses a JSON document from a [io.Reader],
+// and turn its contents into a slice of [CfgOption].
+//
+// The expected payload is slightly different from [Config] struct.
+//
+// For instance, it uses pointers to make it easier to determine
+// whether a value was set or not.
+//
+// Also, note that the parameter names is slightly different as well.
+// The latter uses long, camel-cased names.
+func CfgOptionsFromJSON(r io.Reader) ([]CfgOption, error) {
+	var cfg struct {
+		Concurrency      *int              `json:"concurrency"`
+		RequestPerSecond *int              `json:"requestPerSecond"`
+		BlindHost        *string           `json:"blindHost"`
+		BlindHostKey     *string           `json:"blindHostKey"`
+		CustomTokens     map[string]string `json:"tokens"`
+		PayloadStrategy  *string           `json:"payloadStrategy"`
+	}
+
+	err := json.NewDecoder(r).Decode(&cfg)
+	if err != nil {
+		return nil, err
+	}
+
+	opts := make([]CfgOption, 0, 5)
+
+	if cfg.Concurrency != nil && *cfg.Concurrency > 0 {
+		opts = append(opts, WithConcurrency(*cfg.Concurrency))
+	}
+
+	if cfg.RequestPerSecond != nil && *cfg.RequestPerSecond > 0 {
+		opts = append(opts, WithRPS(*cfg.RequestPerSecond))
+	}
+
+	if cfg.BlindHost != nil && len(*cfg.BlindHost) > 0 {
+		opts = append(opts, WithBlindHost(*cfg.BlindHost))
+	}
+
+	if cfg.BlindHostKey != nil && len(*cfg.BlindHostKey) > 0 {
+		opts = append(opts, WithBlindHostKey(*cfg.BlindHostKey))
+	}
+
+	if cfg.CustomTokens != nil && len(cfg.CustomTokens) > 0 {
+		opts = append(opts, WithCustomTokens(cfg.CustomTokens))
+	}
+
+	if cfg.PayloadStrategy != nil && len(*cfg.PayloadStrategy) > 0 {
+		opts = append(opts, WithPayloadStrategy(*cfg.PayloadStrategy))
+	}
+
+	return opts, nil
+}
+
+const (
+	PayloadStrategyOnlyOnce PayloadStrategy = "only_once"
+	PayloadStrategyAll      PayloadStrategy = "all"
+)
+
+// PayloadStrategy represents the strategy used to inject payloads
+// during the scan execution. It can be either [PayloadStrategyOnlyOnce]
+// or [PayloadStrategyAll].
+type PayloadStrategy string
+
+// PayloadStrategyFromString converts a string into a [PayloadStrategy].
+func PayloadStrategyFromString(s string) PayloadStrategy {
+	switch s {
+	case string(PayloadStrategyOnlyOnce):
+		return PayloadStrategyOnlyOnce
+	default:
+		// Use [PayloadStrategyAll] as the default value
+		// for every other.
+		return PayloadStrategyAll
+	}
+}
+
+// IsOnlyOnce returns whether the payload strategy is [PayloadStrategyOnlyOnce].
+func (ps PayloadStrategy) IsOnlyOnce() bool {
+	return ps == PayloadStrategyOnlyOnce
+}
+
+// String returns the string representation of the [PayloadStrategy].
+func (ps PayloadStrategy) String() string {
+	switch ps {
+	case PayloadStrategyOnlyOnce:
+		return string(PayloadStrategyOnlyOnce)
+	case PayloadStrategyAll:
+		return string(PayloadStrategyAll)
+	default:
+		return unknown
+	}
+}
+
+const unknown = "Unknown"