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

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
+}