fn_registry/cpp/functions/infra/secret_store.md

id, name, kind, lang, domain, version, purity, signature, description, tags, uses_functions, uses_types, returns, returns_optional, error_type, imports, example, tested, tests, test_file_path, file_path, params_schema

id	name	kind	lang	domain	version	purity	signature	description	tags	uses_functions	uses_types	returns	returns_optional	error_type	imports	example	tested	tests	test_file_path	file_path	params_schema
secret_store_cpp_infra	secret_store	function	cpp	infra	1.0.0	impure	fn_secret::encrypt(plaintext) -> blob; fn_secret::decrypt(blob) -> string; fn_secret::is_strong() -> bool	Encrypt/decrypt sensitive strings for local SQLite storage. Windows: DPAPI (user-bound, machine-local, cryptographically strong). Linux/WSL fallback: XOR with per-user seed key (not crypto-secure, shows warning). Used by agents_dashboard to store API keys.	security credentials dpapi encrypt infra agents				false		infra/secret_store.h	#include "infra/secret_store.h" // Encrypt an API key before storing in SQLite: std::string apikey = "sk-mykey-123"; auto blob = fn_secret::encrypt(apikey); // store blob in SQLite BLOB column... // Decrypt when needed: std::string recovered = fn_secret::decrypt(blob); assert(recovered == apikey); // Check platform strength: if (!fn_secret::is_strong()) { // Show warning: Linux fallback is NOT crypto-secure }	false			cpp/functions/infra/secret_store.cpp	{"params":[{"name":"plaintext","desc":"Sensitive string to encrypt (API key, password, token)."},{"name":"blob","desc":"Opaque byte vector returned by encrypt(), stored as SQLite BLOB."}],"output":"encrypt returns vector<uint8_t> blob (empty on failure). decrypt returns plaintext string (empty on failure). is_strong() returns true on Windows (DPAPI), false on Linux (XOR fallback)."}

secret_store

Encrypt/decrypt sensitive credentials for local SQLite storage.

Ejemplo

#include "infra/secret_store.h"

// Store API key encrypted:
std::vector<uint8_t> blob = fn_secret::encrypt("my-api-key-here");
// Insert blob into SQLite BLOB column via sqlite3_bind_blob()...

// Recover:
std::string key = fn_secret::decrypt(blob);

// Base64 helpers for TEXT columns:
std::string b64 = fn_secret::encrypt_b64("my-api-key-here");
std::string back = fn_secret::decrypt_b64(b64);

// Platform check (show warning on Linux):
if (!fn_secret::is_strong()) {
    fn_log::warn("[security] apikey stored with weak Linux fallback encryption");
}

Cuando usarla

Antes de guardar una API key, token o contrasena en SQLite local. Siempre usar fn::local_path("app.db") para la DB. En Windows (DPAPI) la clave nunca sale de la maquina. En Linux, mostrar aviso en UI de que la proteccion es basica.

Gotchas

• DPAPI is Windows-only: el blob cifrado en Windows NO se puede descifrar en Linux y viceversa. Si el usuario mueve la DB entre plataformas, las credenciales se pierden — debe reingresar la apikey.
• Linux fallback NO es criptograficamente seguro: XOR con semilla derivada de username+hostname. Previene lectura casual pero no protege contra atacante con acceso al sistema.
• CryptProtectData es sincrono: no llamar desde el thread principal con datos grandes. Para una apikey (tipicamente <200 bytes) el coste es despreciable.
• Linkear crypt32.lib en Windows: el .cpp tiene #pragma comment(lib, "crypt32.lib") — no necesita entry en CMakeLists para MSVC. Con MinGW se enlaza automaticamente si se incluye wincrypt.h.