feat(tfstated): implement GET and POST methods, states are encrypted in a sqlite3 database

18 files changed, 627 insertions, 2 deletions

diff --git a/.gitignore b/.gitignore
index 1788154..8bdbc77 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,4 @@
 tfstate
+tfstate.db
+tfstate.db-shm
+tfstate.db-wal
diff --git a/cmd/tfstated/get.go b/cmd/tfstated/get.go
new file mode 100644
index 0000000..6de78a5
--- /dev/null
+++ b/cmd/tfstated/get.go
@@ -0,0 +1,35 @@
+package main
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"net/http"
+
+	"git.adyxax.org/adyxax/tfstated/pkg/database"
+)
+
+func handleGet(db *database.DB) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Cache-Control", "no-store, no-cache")
+		w.Header().Set("Content-Type", "application/json")
+
+		if r.URL.Path == "/" {
+			w.WriteHeader(http.StatusBadRequest)
+			_, _ = w.Write([]byte("{\"msg\": \"No state path provided, cannot GET /\"}"))
+			return
+		}
+
+		if data, err := db.GetState(r.URL.Path); err != nil {
+			if errors.Is(err, sql.ErrNoRows) {
+				w.WriteHeader(http.StatusNotFound)
+			} else {
+				w.WriteHeader(http.StatusInternalServerError)
+			}
+			_, _ = w.Write([]byte(fmt.Sprintf("{\"msg\": \"%+v\"}", err)))
+		} else {
+			w.WriteHeader(http.StatusOK)
+			_, _ = w.Write(data)
+		}
+	})
+}
diff --git a/cmd/tfstated/main.go b/cmd/tfstated/main.go
index e0b33a5..61248bc 100644
--- a/cmd/tfstated/main.go
+++ b/cmd/tfstated/main.go
@@ -12,6 +12,8 @@ import (
 	"os/signal"
 	"sync"
 	"time"
+
+	"git.adyxax.org/adyxax/tfstated/pkg/database"
 )
 
 type Config struct {
@@ -22,6 +24,7 @@ type Config struct {
 func run(
 	ctx context.Context,
 	config *Config,
+	db *database.DB,
 	args []string,
 	getenv func(string) string,
 	stdin io.Reader,
@@ -30,10 +33,20 @@ func run(
 	ctx, cancel := signal.NotifyContext(ctx, os.Interrupt)
 	defer cancel()
 
+	dataEncryptionKey := getenv("DATA_ENCRYPTION_KEY")
+	if dataEncryptionKey == "" {
+		return fmt.Errorf("the DATA_ENCRYPTION_KEY environment variable is not set")
+	}
+	if err := db.SetDataEncryptionKey(dataEncryptionKey); err != nil {
+		return err
+	}
+
 	mux := http.NewServeMux()
 	addRoutes(
 		mux,
+		db,
 	)
+
 	httpServer := &http.Server{
 		Addr:    net.JoinHostPort(config.Host, config.Port),
 		Handler: mux,
@@ -79,9 +92,17 @@ func main() {
 		Port: "8080",
 	}
 
+	db, err := database.NewDB(ctx, "./tfstate.db?_txlock=immediate")
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "database init error: %+v\n", err)
+		os.Exit(1)
+	}
+	defer db.Close()
+
 	if err := run(
 		ctx,
 		&config,
+		db,
 		os.Args,
 		os.Getenv,
 		os.Stdin,
diff --git a/cmd/tfstated/post.go b/cmd/tfstated/post.go
new file mode 100644
index 0000000..e47f5ad
--- /dev/null
+++ b/cmd/tfstated/post.go
@@ -0,0 +1,32 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+
+	"git.adyxax.org/adyxax/tfstated/pkg/database"
+)
+
+func handlePost(db *database.DB) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		if r.URL.Path == "/" {
+			w.WriteHeader(http.StatusBadRequest)
+			_, _ = w.Write([]byte("{\"msg\": \"No state path provided, cannot POST /\"}"))
+			return
+		}
+		data, err := io.ReadAll(r.Body)
+		if err != nil {
+			w.WriteHeader(http.StatusBadRequest)
+			_, _ = w.Write([]byte(fmt.Sprintf("{\"msg\": \"failed to read request body: %+v\"}", err)))
+			return
+		}
+		if err := db.SetState(r.URL.Path, data); err != nil {
+			w.WriteHeader(http.StatusInternalServerError)
+			_, _ = w.Write([]byte(fmt.Sprintf("{\"msg\": \"%+v\"}", err)))
+		} else {
+			w.WriteHeader(http.StatusOK)
+		}
+	})
+}
diff --git a/cmd/tfstated/routes.go b/cmd/tfstated/routes.go
index f583fc7..32ab111 100644
--- a/cmd/tfstated/routes.go
+++ b/cmd/tfstated/routes.go
@@ -1,7 +1,16 @@
 package main
 
-import "net/http"
+import (
+	"net/http"
 
-func addRoutes(mux *http.ServeMux) {
+	"git.adyxax.org/adyxax/tfstated/pkg/database"
+)
+
+func addRoutes(
+	mux *http.ServeMux,
+	db *database.DB,
+) {
 	mux.Handle("GET /healthz", handleHealthz())
+	mux.Handle("GET /", handleGet(db))
+	mux.Handle("POST /", handlePost(db))
 }
diff --git a/go.mod b/go.mod
index 9a846e2..14aa55d 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,5 @@
 module git.adyxax.org/adyxax/tfstated
 
 go 1.23.1
+
+require github.com/mattn/go-sqlite3 v1.14.23
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..32531fa
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,2 @@
+github.com/mattn/go-sqlite3 v1.14.23 h1:gbShiuAP1W5j9UOksQ06aiiqPMxYecovVGwmTxWtuw0=
+github.com/mattn/go-sqlite3 v1.14.23/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
diff --git a/pkg/database/db.go b/pkg/database/db.go
new file mode 100644
index 0000000..2744570
--- /dev/null
+++ b/pkg/database/db.go
@@ -0,0 +1,103 @@
+package database
+
+import (
+	"context"
+	"database/sql"
+	"runtime"
+
+	"git.adyxax.org/adyxax/tfstated/pkg/scrypto"
+)
+
+func initDB(ctx context.Context, url string) (*sql.DB, error) {
+	db, err := sql.Open("sqlite3", url)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		if err != nil {
+			_ = db.Close()
+		}
+	}()
+	if _, err = db.ExecContext(ctx, "PRAGMA busy_timeout = 5000"); err != nil {
+		return nil, err
+	}
+
+	return db, nil
+}
+
+type DB struct {
+	ctx               context.Context
+	dataEncryptionKey scrypto.AES256Key
+	readDB            *sql.DB
+	writeDB           *sql.DB
+}
+
+func NewDB(ctx context.Context, url string) (*DB, error) {
+	readDB, err := initDB(ctx, url)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		if err != nil {
+			_ = readDB.Close()
+		}
+	}()
+	readDB.SetMaxOpenConns(max(4, runtime.NumCPU()))
+
+	writeDB, err := initDB(ctx, url)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		if err != nil {
+			_ = writeDB.Close()
+		}
+	}()
+	writeDB.SetMaxOpenConns(1)
+
+	db := DB{
+		ctx:     ctx,
+		readDB:  readDB,
+		writeDB: writeDB,
+	}
+	if _, err = db.Exec("PRAGMA foreign_keys = ON"); err != nil {
+		return nil, err
+	}
+	if _, err = db.Exec("PRAGMA cache_size = 10000000"); err != nil {
+		return nil, err
+	}
+	if _, err = db.Exec("PRAGMA journal_mode = WAL"); err != nil {
+		return nil, err
+	}
+	if _, err = db.Exec("PRAGMA synchronous = NORMAL"); err != nil {
+		return nil, err
+	}
+	if err = db.migrate(); err != nil {
+		return nil, err
+	}
+
+	return &db, nil
+}
+
+func (db *DB) Begin() (*sql.Tx, error) {
+	return db.writeDB.Begin()
+}
+
+func (db *DB) Close() error {
+	if err := db.readDB.Close(); err != nil {
+		_ = db.writeDB.Close()
+	}
+	return db.writeDB.Close()
+}
+
+func (db *DB) Exec(query string, args ...any) (sql.Result, error) {
+	return db.writeDB.ExecContext(db.ctx, query, args...)
+}
+
+func (db *DB) QueryRow(query string, args ...any) *sql.Row {
+	return db.readDB.QueryRowContext(db.ctx, query, args...)
+}
+
+func (db *DB) SetDataEncryptionKey(s string) error {
+	return db.dataEncryptionKey.FromBase64(s)
+}
diff --git a/pkg/database/migrations.go b/pkg/database/migrations.go
new file mode 100644
index 0000000..b460884
--- /dev/null
+++ b/pkg/database/migrations.go
@@ -0,0 +1,63 @@
+package database
+
+import (
+	"embed"
+	"io/fs"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+//go:embed sql/*.sql
+var schemaFiles embed.FS
+
+func (db *DB) migrate() error {
+	statements := make([]string, 0)
+	err := fs.WalkDir(schemaFiles, ".", func(path string, d fs.DirEntry, err error) error {
+		if d.IsDir() || err != nil {
+			return err
+		}
+		var stmts []byte
+		if stmts, err = schemaFiles.ReadFile(path); err != nil {
+			return err
+		} else {
+			statements = append(statements, string(stmts))
+		}
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+
+	tx, err := db.Begin()
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err != nil {
+			_ = tx.Rollback()
+		}
+	}()
+
+	var version int
+	if err = tx.QueryRowContext(db.ctx, `SELECT version FROM schema_version;`).Scan(&version); err != nil {
+		if err.Error() == "no such table: schema_version" {
+			version = 0
+		} else {
+			return err
+		}
+	}
+
+	for version < len(statements) {
+		if _, err = tx.ExecContext(db.ctx, statements[version]); err != nil {
+			return err
+		}
+		version++
+	}
+	if _, err = tx.ExecContext(db.ctx, `DELETE FROM schema_version; INSERT INTO schema_version (version) VALUES (?);`, version); err != nil {
+		return err
+	}
+	if err = tx.Commit(); err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/pkg/database/sql/000_init.sql b/pkg/database/sql/000_init.sql
new file mode 100644
index 0000000..0248896
--- /dev/null
+++ b/pkg/database/sql/000_init.sql
@@ -0,0 +1,10 @@
+CREATE TABLE schema_version (
+  version INTEGER NOT NULL
+) STRICT;
+
+CREATE TABLE states (
+  id INTEGER PRIMARY KEY,
+  name TEXT NOT NULL,
+  data BLOB NOT NULL
+) STRICT;
+CREATE UNIQUE INDEX states_name on states(name);
diff --git a/pkg/database/states.go b/pkg/database/states.go
new file mode 100644
index 0000000..ef2263b
--- /dev/null
+++ b/pkg/database/states.go
@@ -0,0 +1,30 @@
+package database
+
+import (
+	"database/sql"
+)
+
+func (db *DB) GetState(name string) ([]byte, error) {
+	var encryptedData []byte
+	err := db.QueryRow(`SELECT data FROM states WHERE name = ?;`, name).Scan(&encryptedData)
+	if err != nil {
+		return nil, err
+	}
+	return db.dataEncryptionKey.DecryptAES256(encryptedData)
+}
+
+func (db *DB) SetState(name string, data []byte) error {
+	encryptedData, err := db.dataEncryptionKey.EncryptAES256(data)
+	if err != nil {
+		return err
+	}
+	_, err = db.Exec(
+		`INSERT INTO states(name, data) VALUES (:name, :data) ON CONFLICT DO UPDATE SET data = :data WHERE name = :name;`,
+		sql.Named("data", encryptedData),
+		sql.Named("name", name),
+	)
+	if err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/pkg/scrypto/LICENSE b/pkg/scrypto/LICENSE
new file mode 100644
index 0000000..aeafaf4
--- /dev/null
+++ b/pkg/scrypto/LICENSE
@@ -0,0 +1,13 @@
+Copyright (c) 2023-2024 Nicolas Martyanoff <nicolas@n16f.net>
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+PERFORMANCE OF THIS SOFTWARE.
diff --git a/pkg/scrypto/README.md b/pkg/scrypto/README.md
new file mode 100644
index 0000000..e83bc8e
--- /dev/null
+++ b/pkg/scrypto/README.md
@@ -0,0 +1,5 @@
+Original code imported from https://github.com/galdor/go-service/tree/master/pkg/scrypto
+
+Alterations:
+- converted the EncryptAES256 and DecryptAES256 functions to methods
+- rewrote the tests to get rid of the dependency on testify
diff --git a/pkg/scrypto/aes256.go b/pkg/scrypto/aes256.go
new file mode 100644
index 0000000..27a39d6
--- /dev/null
+++ b/pkg/scrypto/aes256.go
@@ -0,0 +1,138 @@
+package scrypto
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"encoding/base64"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+)
+
+type AES256Key [32]byte
+
+const (
+	AES256IVSize int = aes.BlockSize
+)
+
+var Zero = AES256Key{}
+
+func (key *AES256Key) Bytes() []byte {
+	return key[:]
+}
+
+func (key *AES256Key) IsZero() bool {
+	return bytes.Equal(key.Bytes(), Zero.Bytes())
+}
+
+func (key *AES256Key) Hex() string {
+	return hex.EncodeToString(key[:])
+}
+
+func (key *AES256Key) FromHex(s string) error {
+	data, err := hex.DecodeString(s)
+	if err != nil {
+		return err
+	}
+
+	if len(data) != 32 {
+		return fmt.Errorf("invalid key size")
+	}
+
+	copy((*key)[:], data[:32])
+
+	return nil
+}
+
+func (key *AES256Key) FromBase64(s string) error {
+	data, err := base64.StdEncoding.DecodeString(s)
+	if err != nil {
+		return err
+	}
+
+	if len(data) != 32 {
+		return fmt.Errorf("invalid key size")
+	}
+
+	copy((*key)[:], data[:32])
+
+	return nil
+}
+
+func (key *AES256Key) MarshalJSON() ([]byte, error) {
+	s := base64.StdEncoding.EncodeToString(key[:])
+	return json.Marshal(s)
+}
+
+func (pkey *AES256Key) UnmarshalJSON(data []byte) error {
+	var s string
+	if err := json.Unmarshal(data, &s); err != nil {
+		return err
+	}
+
+	key, err := base64.StdEncoding.DecodeString(s)
+	if err != nil {
+		return fmt.Errorf("cannot decode base64 value: %w", err)
+	}
+
+	if len(key) != 32 {
+		return fmt.Errorf("invalid key size (must be 32 bytes long)")
+	}
+
+	copy(pkey[:], key)
+
+	return nil
+}
+
+func (key *AES256Key) EncryptAES256(inputData []byte) ([]byte, error) {
+	blockCipher, err := aes.NewCipher(key[:])
+	if err != nil {
+		return nil, fmt.Errorf("cannot create cipher: %w", err)
+	}
+
+	paddedData := PadPKCS5(inputData, aes.BlockSize)
+
+	outputData := make([]byte, AES256IVSize+len(paddedData))
+
+	iv := outputData[:AES256IVSize]
+	encryptedData := outputData[AES256IVSize:]
+
+	if _, err := rand.Read(iv); err != nil {
+		return nil, fmt.Errorf("cannot generate iv: %w", err)
+	}
+
+	encrypter := cipher.NewCBCEncrypter(blockCipher, iv)
+	encrypter.CryptBlocks(encryptedData, paddedData)
+
+	return outputData, nil
+}
+
+func (key *AES256Key) DecryptAES256(inputData []byte) ([]byte, error) {
+	blockCipher, err := aes.NewCipher(key[:])
+	if err != nil {
+		return nil, fmt.Errorf("cannot create cipher: %w", err)
+	}
+
+	if len(inputData) < AES256IVSize {
+		return nil, fmt.Errorf("truncated data")
+	}
+
+	iv := inputData[:AES256IVSize]
+	paddedData := inputData[AES256IVSize:]
+
+	if len(paddedData)%aes.BlockSize != 0 {
+		return nil, fmt.Errorf("invalid padded data length")
+	}
+
+	decrypter := cipher.NewCBCDecrypter(blockCipher, iv)
+	decrypter.CryptBlocks(paddedData, paddedData)
+
+	outputData, err := UnpadPKCS5(paddedData, aes.BlockSize)
+	if err != nil {
+		return nil, fmt.Errorf("invalid padded data: %w", err)
+	}
+
+	return outputData, nil
+}
diff --git a/pkg/scrypto/aes256_test.go b/pkg/scrypto/aes256_test.go
new file mode 100644
index 0000000..9914625
--- /dev/null
+++ b/pkg/scrypto/aes256_test.go
@@ -0,0 +1,60 @@
+package scrypto
+
+import (
+	"encoding/hex"
+	"slices"
+	"strings"
+	"testing"
+)
+
+func TestAES256KeyHex(t *testing.T) {
+	testKeyHex := "28278b7c0a25f01d3cab639633b9487f9ea1e9a2176dc9595a3f01323aa44284"
+	testKey, _ := hex.DecodeString(testKeyHex)
+
+	var key AES256Key
+	if err := key.FromHex(testKeyHex); err != nil {
+		t.Errorf("got unexpected error %+v", err)
+	}
+	if slices.Compare(testKey, key[:]) != 0 {
+		t.Errorf("got %v, wanted %v", testKey, key[:])
+	}
+	if strings.Compare(testKeyHex, key.Hex()) != 0 {
+		t.Errorf("got %v, wanted %v", testKeyHex, key.Hex())
+	}
+}
+
+func TestAES256(t *testing.T) {
+	keyHex := "28278b7c0a25f01d3cab639633b9487f9ea1e9a2176dc9595a3f01323aa44284"
+	var key AES256Key
+	if err := key.FromHex(keyHex); err != nil {
+		t.Errorf("got unexpected error %+v", err)
+	}
+
+	data := []byte("Hello world!")
+	encryptedData, err := key.EncryptAES256(data)
+	if err != nil {
+		t.Errorf("got unexpected error when encrypting data %+v", err)
+	}
+
+	decryptedData, err := key.DecryptAES256(encryptedData)
+	if err != nil {
+		t.Errorf("got unexpected error when decrypting data %+v", err)
+	}
+
+	if slices.Compare(data, decryptedData) != 0 {
+		t.Errorf("got %v, wanted %v", decryptedData, data)
+	}
+}
+
+func TestAES256InvalidData(t *testing.T) {
+	keyHex := "28278b7c0a25f01d3cab639633b9487f9ea1e9a2176dc9595a3f01323aa44284"
+	var key AES256Key
+	if err := key.FromHex(keyHex); err != nil {
+		t.Errorf("got unexpected error when converting data from base64: %+v", err)
+	}
+
+	iv := make([]byte, AES256IVSize)
+	if _, err := key.DecryptAES256(append(iv, []byte("foo")...)); err == nil {
+		t.Error("decrypting operation should have failed")
+	}
+}
diff --git a/pkg/scrypto/pkcs5.go b/pkg/scrypto/pkcs5.go
new file mode 100644
index 0000000..b41c564
--- /dev/null
+++ b/pkg/scrypto/pkcs5.go
@@ -0,0 +1,31 @@
+package scrypto
+
+import (
+	"bytes"
+	"fmt"
+)
+
+func PadPKCS5(data []byte, blockSize int) []byte {
+	paddingSize := blockSize - len(data)%blockSize
+	padding := bytes.Repeat([]byte{byte(paddingSize)}, paddingSize)
+
+	return append(data, padding...)
+}
+
+func UnpadPKCS5(data []byte, blockSize int) ([]byte, error) {
+	dataSize := len(data)
+	if dataSize%blockSize != 0 {
+		return nil, fmt.Errorf("truncated data")
+	}
+
+	if len(data) == 0 {
+		return data, nil
+	} else {
+		paddingSize := int(data[dataSize-1])
+		if paddingSize > dataSize || paddingSize > blockSize {
+			return nil, fmt.Errorf("invalid padding size %d", paddingSize)
+		}
+
+		return data[:dataSize-paddingSize], nil
+	}
+}
diff --git a/pkg/scrypto/pkcs5_test.go b/pkg/scrypto/pkcs5_test.go
new file mode 100644
index 0000000..8bd1a1d
--- /dev/null
+++ b/pkg/scrypto/pkcs5_test.go
@@ -0,0 +1,52 @@
+package scrypto
+
+import (
+	"slices"
+	"testing"
+)
+
+func TestPadPKCS5(t *testing.T) {
+	tests := []struct {
+		data []byte
+		want []byte
+	}{
+		{data: []byte(""), want: []byte("\x04\x04\x04\x04")},
+		{data: []byte("a"), want: []byte("a\x03\x03\x03")},
+		{data: []byte("ab"), want: []byte("ab\x02\x02")},
+		{data: []byte("abc"), want: []byte("abc\x01")},
+		{data: []byte("abcd"), want: []byte("abcd\x04\x04\x04\x04")},
+		{data: []byte("abcde"), want: []byte("abcde\x03\x03\x03")},
+		{data: []byte("abcdefgh"), want: []byte("abcdefgh\x04\x04\x04\x04")},
+	}
+	for _, tt := range tests {
+		got := PadPKCS5(tt.data, 4)
+		if slices.Compare(got, tt.want) != 0 {
+			t.Errorf("got %v, want %v", got, tt.want)
+		}
+	}
+}
+
+func TestUnpadPKCS5(t *testing.T) {
+	tests := []struct {
+		data []byte
+		want []byte
+	}{
+		{data: []byte("\x04\x04\x04\x04"), want: []byte("")},
+		{data: []byte("a\x03\x03\x03"), want: []byte("a")},
+		{data: []byte("ab\x02\x02"), want: []byte("ab")},
+		{data: []byte("abc\x01"), want: []byte("abc")},
+		{data: []byte("abcd\x04\x04\x04\x04"), want: []byte("abcd")},
+		{data: []byte("abcde\x03\x03\x03"), want: []byte("abcde")},
+		{data: []byte("abcdefgh\x04\x04\x04\x04"), want: []byte("abcdefgh")},
+	}
+	for _, tt := range tests {
+		got, err := UnpadPKCS5(tt.data, 4)
+		if err != nil {
+			t.Errorf("got err %+v while wanted %v", err, tt.want)
+		} else {
+			if slices.Compare(got, tt.want) != 0 {
+				t.Errorf("got %v, want %v", got, tt.want)
+			}
+		}
+	}
+}
diff --git a/pkg/scrypto/random.go b/pkg/scrypto/random.go
new file mode 100644
index 0000000..47d9557
--- /dev/null
+++ b/pkg/scrypto/random.go
@@ -0,0 +1,16 @@
+package scrypto
+
+import (
+	"crypto/rand"
+	"fmt"
+)
+
+func RandomBytes(n int) []byte {
+	data := make([]byte, n)
+
+	if _, err := rand.Read(data); err != nil {
+		panic(fmt.Sprintf("cannot generate random data: %+v", err))
+	}
+
+	return data
+}