sectools

Security-focused Go helpers for file I/O, in-memory handling of sensitive data, auth tokens, password hashing, input validation/sanitization, and safe numeric conversions.

Features

• Secure file reads scoped to the system temp directory
• Secure file writes with atomic replace and permissions
• Secure directory creation/listing with root scoping and symlink checks
• Streaming-safe writes from readers with size caps
• Secure temp file/dir helpers with root scoping
• Secure remove and copy helpers with root scoping
• Symlink checks and root-scoped file access using os.OpenRoot
• Secure in-memory buffers with best-effort zeroization
• JWT/PASETO helpers with strict validation and safe defaults
• MFA helpers for TOTP/HOTP provisioning, verification, and backup codes
• Password hashing presets for argon2id/bcrypt with rehash detection
• Email and URL validation with optional DNS/redirect/reputation checks
• Random token generation and validation with entropy/length caps
• Bounded base64/hex encoding and strict JSON decoding
• Size-bounded JSON/YAML/XML parsing helpers
• Redaction helpers and secret detection heuristics for logs/config dumps
• Opinionated TLS configs with TLS 1.2/1.3 defaults, mTLS, and optional post-quantum key exchange
• HTML/Markdown sanitization, SQL/NoSQL input guards, and filename sanitizers
• Safe integer conversion helpers with overflow/negative guards

Requirements

• Go 1.25.5+ (see go.mod)

Installation

go get github.com/hyp3rd/sectools

Usage

Secure file read

package main

import (
 "os"
 "path/filepath"

 sectools "github.com/hyp3rd/sectools/pkg/io"
)

func main() {
 path := filepath.Join(os.TempDir(), "example.txt")
 _ = os.WriteFile(path, []byte("secret"), 0o600)

 client := sectools.New()
 data, err := client.ReadFile(filepath.Base(path))
 if err != nil {
  panic(err)
 }

 _ = data
}

Secure buffer

package main

import (
 "os"
 "path/filepath"

 sectools "github.com/hyp3rd/sectools/pkg/io"
)

func main() {
 path := filepath.Join(os.TempDir(), "example.txt")
 _ = os.WriteFile(path, []byte("secret"), 0o600)

 client := sectools.New()
 buf, err := client.ReadFileWithSecureBuffer(filepath.Base(path))
 if err != nil {
  panic(err)
 }
 defer buf.Clear()

 _ = buf.Bytes()
}

Safe integer conversions

package main

import (
 "fmt"

 "github.com/hyp3rd/sectools/pkg/converters"
)

func main() {
 value, err := converters.SafeUint64FromInt64(42)
 fmt.Println(value, err)
}

Secure file write

package main

import (
 sectools "github.com/hyp3rd/sectools/pkg/io"
)

func main() {
 client, err := sectools.NewWithOptions(
  sectools.WithWriteSyncDir(true),
 )
 if err != nil {
  panic(err)
 }

 err = client.WriteFile("example.txt", []byte("secret"))
 if err != nil {
  panic(err)
 }
}

JWT sign/verify

package main

import (
 "time"

 "github.com/golang-jwt/jwt/v5"

 sectauth "github.com/hyp3rd/sectools/pkg/auth"
)

func main() {
 signer, err := sectauth.NewJWTSigner(
  sectauth.WithJWTSigningAlgorithm("HS256"),
  sectauth.WithJWTSigningKey([]byte("secret")),
 )
 if err != nil {
  panic(err)
 }

 verifier, err := sectauth.NewJWTVerifier(
  sectauth.WithJWTAllowedAlgorithms("HS256"),
  sectauth.WithJWTVerificationKey([]byte("secret")),
  sectauth.WithJWTIssuer("sectools"),
  sectauth.WithJWTAudience("apps"),
 )
 if err != nil {
  panic(err)
 }

 claims := jwt.RegisteredClaims{
  Issuer:    "sectools",
  Audience:  jwt.ClaimStrings{"apps"},
  ExpiresAt: jwt.NewNumericDate(time.Now().Add(time.Hour)),
 }

 token, err := signer.Sign(claims)
 if err != nil {
  panic(err)
 }

_ = verifier.Verify(token, &jwt.RegisteredClaims{})
}

MFA (TOTP)

package main

import (
 "fmt"

 "github.com/hyp3rd/sectools/pkg/mfa"
)

func main() {
 key, err := mfa.GenerateTOTPKey(
  mfa.WithTOTPKeyIssuer("sectools"),
  mfa.WithTOTPKeyAccountName("user@example.com"),
 )
 if err != nil {
  panic(err)
 }

 fmt.Println(key.URL())

 totp, err := mfa.NewTOTP(key.Secret())
 if err != nil {
  panic(err)
 }

 ok, err := totp.Verify("123456")
 if err != nil {
  panic(err)
 }

 _ = ok
}

package main

import (
 "github.com/hyp3rd/sectools/pkg/mfa"
)

func main() {
 manager, err := mfa.NewBackupCodeManager()
 if err != nil {
  panic(err)
 }

 set, err := manager.Generate()
 if err != nil {
  panic(err)
 }

 // Store set.Hashes and display set.Codes once.
 _, _, _ = manager.Verify(set.Codes[0], set.Hashes)
}

Password hashing

package main

import (
 "github.com/hyp3rd/sectools/pkg/password"
)

func main() {
 hasher, err := password.NewArgon2id(password.Argon2idBalanced())
 if err != nil {
  panic(err)
 }

 hash, err := hasher.Hash([]byte("secret"))
 if err != nil {
  panic(err)
 }

 ok, needsRehash, err := hasher.Verify([]byte("secret"), hash)
 if err != nil {
  panic(err)
 }

 _, _ = ok, needsRehash
}

Input validation

package main

import (
 "context"

 "github.com/hyp3rd/sectools/pkg/validate"
)

func main() {
 emailValidator, err := validate.NewEmailValidator(
  validate.WithEmailVerifyDomain(true),
 )
 if err != nil {
  panic(err)
 }

 _, _ = emailValidator.Validate(context.Background(), "user@example.com")

 urlValidator, err := validate.NewURLValidator(
  validate.WithURLCheckRedirects(3),
 )
 if err != nil {
  panic(err)
 }

 _, _ = urlValidator.Validate(context.Background(), "https://example.com")
}

Tokens

package main

import (
 "github.com/hyp3rd/sectools/pkg/tokens"
)

func main() {
 generator, err := tokens.NewGenerator()
 if err != nil {
  panic(err)
 }

 validator, err := tokens.NewValidator()
 if err != nil {
  panic(err)
 }

 token, _ := generator.Generate()
 _, _ = validator.Validate(token)
}

Encoding

package main

import (
 "github.com/hyp3rd/sectools/pkg/encoding"
)

func main() {
 encoded, _ := encoding.EncodeBase64([]byte("secret"))
 _, _ = encoding.DecodeBase64(encoded)

 type payload struct {
  Name string `json:"name"`
 }

_ = encoding.DecodeJSON([]byte(`{"name":"alpha"}`), &payload{})
}

Parsing limits

package main

import (
 "strings"

 "github.com/hyp3rd/sectools/pkg/limits"
)

func main() {
 var payload map[string]any

 reader := strings.NewReader(`{"name":"alpha"}`)
 err := limits.DecodeJSON(reader, &payload, limits.WithMaxBytes(1<<20))
 if err != nil {
  panic(err)
 }
}

Secrets

package main

import (
 "github.com/hyp3rd/sectools/pkg/secrets"
)

func main() {
 detector, err := secrets.NewSecretDetector()
 if err != nil {
  panic(err)
 }

 _ = detector.DetectAny("token=ghp_abcdefghijklmnopqrstuvwxyz1234567890")

 redactor, err := secrets.NewRedactor(secrets.WithRedactionDetector(detector))
 if err != nil {
  panic(err)
 }

 fields := map[string]any{"password": "secret"}
 _ = redactor.RedactFields(fields)
}

TLS config

Hybrid post-quantum key exchange is optional and only negotiated in TLS 1.3. Peers that do not support it will fall back to X25519.

package main

import (
 "crypto/tls"

 "github.com/hyp3rd/sectools/pkg/tlsconfig"
)

func main() {
 serverConfig, err := tlsconfig.NewServerConfig(
  tlsconfig.WithCertificates(tls.Certificate{}),
  tlsconfig.WithPostQuantumKeyExchange(),
  tlsconfig.WithClientAuth(tls.RequireAndVerifyClientCert),
 )
 if err != nil {
  panic(err)
 }

 _ = serverConfig
}

package main

import (
 "crypto/x509"

 "github.com/hyp3rd/sectools/pkg/tlsconfig"
)

func main() {
 roots, err := x509.SystemCertPool()
 if err != nil {
  panic(err)
 }

 clientConfig, err := tlsconfig.NewClientConfig(
  tlsconfig.WithRootCAs(roots),
  tlsconfig.WithServerName("api.example.com"),
  tlsconfig.WithTLS13Only(),
  tlsconfig.WithPostQuantumKeyExchange(),
 )
 if err != nil {
  panic(err)
 }

 _ = clientConfig
}

Sanitization

package main

import (
 "github.com/hyp3rd/sectools/pkg/sanitize"
)

func main() {
 htmlSanitizer, err := sanitize.NewHTMLSanitizer()
 if err != nil {
  panic(err)
 }

 safeHTML, _ := htmlSanitizer.Sanitize("<b>hello</b>")

 sqlSanitizer, err := sanitize.NewSQLSanitizer(
  sanitize.WithSQLMode(sanitize.SQLModeIdentifier),
  sanitize.WithSQLAllowQualifiedIdentifiers(true),
 )
 if err != nil {
  panic(err)
 }

 safeIdentifier, _ := sqlSanitizer.Sanitize("public.users")

 detector, err := sanitize.NewNoSQLInjectionDetector()
 if err != nil {
  panic(err)
 }

 _ = detector.Detect(`{"username":{"$ne":null}}`)

 _, _ = safeHTML, safeIdentifier
}

Security and behavior notes

• ReadFile only permits relative paths under os.TempDir() by default. Use NewWithOptions with WithAllowAbsolute to allow absolute paths or alternate roots.
• Paths containing .. are rejected to prevent directory traversal.
• ReadFile has no default size cap; use WithReadMaxSize when file size is untrusted.
• Symlinks are rejected by default; when allowed, paths that resolve outside the allowed roots are rejected.
• File access is scoped with os.OpenRoot on the resolved root when symlinks are disallowed. When symlinks are allowed, files are opened via resolved paths after symlink checks. See the Go os.Root docs for platform-specific caveats.
• WriteFile uses atomic replace and fsync by default; set WithWriteDisableAtomic or WithWriteDisableSync only if you accept durability risks. Set WithWriteSyncDir to fsync the parent directory after atomic rename for stronger durability guarantees (may be unsupported on some platforms/filesystems).
• Optional ownership checks are available via WithOwnerUID/WithOwnerGID on Unix platforms.
• SecureBuffer zeroizes memory on Clear() and uses a finalizer as a best-effort fallback; call Clear() when done.

Documentation

• Detailed usage and behavior notes: Usage
• A quick reference for teams using sectools in production: Security checklist

Development

Make Targets (high level)

• prepare-toolchain — install core tools (gci, gofumpt, golangci-lint, staticcheck, govulncheck, gosec)
• prepare-proto-tools — install buf + protoc plugins (optional, controlled by PROTO_ENABLED)
• init — run setup-project.sh with current module and install tooling (respects PROTO_ENABLED)
• lint — gci, gofumpt, staticcheck, golangci-lint
• test / test-race / bench
• vet, sec, proto, run, run-container, update-deps, update-toolchain

Contribution Notes

• Tests required for changes; run make lint test before PRs.
• Suggested branch naming: feat/<scope>, fix/<scope>, chore/<scope>.
• Update docs when altering tooling, Make targets, or setup steps.

Follow the contributing guidelines.

Code of Conduct

Make sure you observe the Code of Conduct.

License

GPL-3.0. See LICENSE for details.