Initial import: n2usenet HTTPS/Nym Usenet gateway

1 files changed, 209 insertions, 0 deletions

diff --git a/internal/config/config.go b/internal/config/config.go
new file mode 100644
index 0000000..5ee60ea
--- /dev/null
+++ b/internal/config/config.go
@@ -0,0 +1,209 @@
+package config
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type Config struct {
+	Listen        string
+	PublicBaseURL string
+
+	SMTP     SMTPConfig
+	Nym      NymConfig
+	Security SecurityConfig
+}
+
+type SMTPConfig struct {
+	Host          string
+	Port          int
+	Recipient     string
+	EnvelopeFrom  string
+	HELO          string
+	TLSServerName string
+	RequireTLS    bool
+	ImplicitTLS   bool
+	Timeout       time.Duration
+	DryRun        bool
+}
+
+type NymConfig struct {
+	Enabled          bool
+	Managed          bool
+	Binary           string
+	Provider         string
+	HomeDir          string
+	ClientID         string
+	SocksAddr        string
+	AnonymousReplies bool
+	StartupTimeout   time.Duration
+}
+
+type SecurityConfig struct {
+	MinHashcashBits int
+	MinMessageBytes int
+	MaxMessageBytes int
+	MaxNewsgroups   int
+	RateLimitCount  int
+	RateLimitWindow time.Duration
+	TrustProxy      bool
+	SecureCookies   bool
+	MessageIDDomain string
+	IdenticonsCLI   string
+	RequireFace     bool
+}
+
+func Load() (Config, error) {
+	cfg := Config{
+		Listen:        env("N2U_LISTEN", "M2U_LISTEN", "127.0.0.1:8095"),
+		PublicBaseURL: env("N2U_PUBLIC_BASE_URL", "M2U_PUBLIC_BASE_URL", "https://n2usenet.virebent.art"),
+		SMTP: SMTPConfig{
+			Host:          env("N2U_SMTP_HOST", "M2U_SMTP_HOST", "mail2news.tcpreset.net"),
+			Port:          envInt("N2U_SMTP_PORT", "M2U_SMTP_PORT", 25),
+			Recipient:     env("N2U_SMTP_RECIPIENT", "M2U_SMTP_RECIPIENT", "mail2news@mail2news.tcpreset.net"),
+			EnvelopeFrom:  env("N2U_SMTP_ENVELOPE_FROM", "M2U_SMTP_ENVELOPE_FROM", "n2usenet@virebent.art"),
+			HELO:          env("N2U_SMTP_HELO", "M2U_SMTP_HELO", "n2usenet.virebent.art"),
+			TLSServerName: env("N2U_SMTP_TLS_SERVER_NAME", "M2U_SMTP_TLS_SERVER_NAME", "mail.tcpreset.net"),
+			RequireTLS:    envBool("N2U_SMTP_REQUIRE_TLS", "M2U_SMTP_REQUIRE_TLS", true),
+			ImplicitTLS:   envBool("N2U_SMTP_IMPLICIT_TLS", "M2U_SMTP_IMPLICIT_TLS", false),
+			Timeout:       envDuration("N2U_SMTP_TIMEOUT", "M2U_SMTP_TIMEOUT", 90*time.Second),
+			DryRun:        envBool("N2U_DRY_RUN", "M2U_DRY_RUN", false),
+		},
+		Nym: NymConfig{
+			Enabled:          envBool("N2U_NYM_ENABLED", "M2U_NYM_ENABLED", true),
+			Managed:          envBool("N2U_NYM_MANAGED", "M2U_NYM_MANAGED", false),
+			Binary:           env("N2U_NYM_BINARY", "M2U_NYM_BINARY", "nym-socks5-client"),
+			Provider:         env("N2U_NYM_PROVIDER", "M2U_NYM_PROVIDER", ""),
+			HomeDir:          env("N2U_NYM_HOME", "M2U_NYM_HOME", "./data/nym"),
+			ClientID:         env("N2U_NYM_CLIENT_ID", "M2U_NYM_CLIENT_ID", "n2usenet"),
+			SocksAddr:        env("N2U_NYM_SOCKS", "M2U_NYM_SOCKS", "127.0.0.1:11080"),
+			AnonymousReplies: envBool("N2U_NYM_ANONYMOUS_REPLIES", "M2U_NYM_ANONYMOUS_REPLIES", true),
+			StartupTimeout:   envDuration("N2U_NYM_STARTUP_TIMEOUT", "M2U_NYM_STARTUP_TIMEOUT", 120*time.Second),
+		},
+		Security: SecurityConfig{
+			MinHashcashBits: envInt("N2U_HASHCASH_MIN_BITS", "M2U_HASHCASH_MIN_BITS", 20),
+			MinMessageBytes: envInt("N2U_MIN_MESSAGE_BYTES", "M2U_MIN_MESSAGE_BYTES", 10),
+			MaxMessageBytes: envInt("N2U_MAX_MESSAGE_BYTES", "M2U_MAX_MESSAGE_BYTES", 65536),
+			MaxNewsgroups:   envInt("N2U_MAX_NEWSGROUPS", "M2U_MAX_NEWSGROUPS", 3),
+			RateLimitCount:  envInt("N2U_RATE_LIMIT_COUNT", "M2U_RATE_LIMIT_COUNT", 10),
+			RateLimitWindow: envDuration("N2U_RATE_LIMIT_WINDOW", "M2U_RATE_LIMIT_WINDOW", time.Hour),
+			TrustProxy:      envBool("N2U_TRUST_PROXY", "M2U_TRUST_PROXY", true),
+			SecureCookies:   envBool("N2U_SECURE_COOKIES", "M2U_SECURE_COOKIES", true),
+			MessageIDDomain: env("N2U_MESSAGE_ID_DOMAIN", "M2U_MESSAGE_ID_DOMAIN", "n2usenet.virebent.art"),
+			IdenticonsCLI:   env("N2U_IDENTICONS_CLI", "M2U_IDENTICONS_CLI", "/usr/local/bin/identicons-cli"),
+			RequireFace:     envBool("N2U_REQUIRE_FACE", "M2U_REQUIRE_FACE", true),
+		},
+	}
+	if err := cfg.Validate(); err != nil {
+		return Config{}, err
+	}
+	return cfg, nil
+}
+
+func (c Config) Validate() error {
+	if _, _, err := net.SplitHostPort(c.Listen); err != nil {
+		return fmt.Errorf("invalid N2U_LISTEN: %w", err)
+	}
+	if c.SMTP.Host == "" {
+		return fmt.Errorf("N2U_SMTP_HOST is required")
+	}
+	if c.SMTP.Port < 1 || c.SMTP.Port > 65535 {
+		return fmt.Errorf("invalid N2U_SMTP_PORT")
+	}
+	if c.SMTP.Recipient == "" {
+		return fmt.Errorf("N2U_SMTP_RECIPIENT is required")
+	}
+	if c.SMTP.EnvelopeFrom == "" {
+		return fmt.Errorf("N2U_SMTP_ENVELOPE_FROM is required")
+	}
+	if c.SMTP.RequireTLS && c.SMTP.TLSServerName == "" {
+		return fmt.Errorf("N2U_SMTP_TLS_SERVER_NAME is required when TLS is required")
+	}
+	if c.Nym.Enabled {
+		if _, _, err := net.SplitHostPort(c.Nym.SocksAddr); err != nil {
+			return fmt.Errorf("invalid N2U_NYM_SOCKS: %w", err)
+		}
+		if c.Nym.Managed && c.Nym.Provider == "" {
+			return fmt.Errorf("N2U_NYM_PROVIDER is required when N2U_NYM_MANAGED=true")
+		}
+	}
+	if c.Security.MinHashcashBits < 1 || c.Security.MinHashcashBits > 32 {
+		return fmt.Errorf("invalid N2U_HASHCASH_MIN_BITS")
+	}
+	if c.Security.MinMessageBytes < 0 || c.Security.MaxMessageBytes <= c.Security.MinMessageBytes {
+		return fmt.Errorf("invalid message size limits")
+	}
+	if c.Security.MaxNewsgroups < 1 || c.Security.MaxNewsgroups > 10 {
+		return fmt.Errorf("invalid N2U_MAX_NEWSGROUPS")
+	}
+	if c.Security.RateLimitCount < 1 {
+		return fmt.Errorf("invalid N2U_RATE_LIMIT_COUNT")
+	}
+	if c.Security.RequireFace && c.Security.IdenticonsCLI == "" {
+		return fmt.Errorf("N2U_IDENTICONS_CLI is required when N2U_REQUIRE_FACE=true")
+	}
+	return nil
+}
+
+func env(primary, legacy, fallback string) string {
+	v, ok := envValue(primary, legacy)
+	if !ok {
+		return fallback
+	}
+	return v
+}
+
+func envBool(primary, legacy string, fallback bool) bool {
+	v, ok := envValue(primary, legacy)
+	if !ok {
+		return fallback
+	}
+	switch strings.ToLower(v) {
+	case "1", "true", "yes", "on":
+		return true
+	case "0", "false", "no", "off":
+		return false
+	default:
+		return fallback
+	}
+}
+
+func envInt(primary, legacy string, fallback int) int {
+	v, ok := envValue(primary, legacy)
+	if !ok {
+		return fallback
+	}
+	n, err := strconv.Atoi(v)
+	if err != nil {
+		return fallback
+	}
+	return n
+}
+
+func envDuration(primary, legacy string, fallback time.Duration) time.Duration {
+	v, ok := envValue(primary, legacy)
+	if !ok {
+		return fallback
+	}
+	if d, err := time.ParseDuration(v); err == nil {
+		return d
+	}
+	if n, err := strconv.Atoi(v); err == nil {
+		return time.Duration(n) * time.Second
+	}
+	return fallback
+}
+
+func envValue(primary, legacy string) (string, bool) {
+	for _, key := range []string{primary, legacy} {
+		v := strings.TrimSpace(os.Getenv(key))
+		if v != "" {
+			return v, true
+		}
+	}
+	return "", false
+}