godot/modules/mbedtls/crypto_mbedtls.cpp
Fabio Alessandrelli e9abcbac3b Fix crash when passing invalid key to Crypto.
In generate_self_signed_certificate
2019-10-09 15:59:17 +02:00

287 lines
10 KiB
C++

/*************************************************************************/
/* crypto_mbedtls.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2019 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2019 Godot Engine contributors (cf. AUTHORS.md) */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
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/*************************************************************************/
#include "crypto_mbedtls.h"
#include "core/os/file_access.h"
#include "core/engine.h"
#include "core/io/certs_compressed.gen.h"
#include "core/io/compression.h"
#include "core/project_settings.h"
#ifdef TOOLS_ENABLED
#include "editor/editor_settings.h"
#endif
#define PEM_BEGIN_CRT "-----BEGIN CERTIFICATE-----\n"
#define PEM_END_CRT "-----END CERTIFICATE-----\n"
#include "mbedtls/pem.h"
#include <mbedtls/debug.h>
CryptoKey *CryptoKeyMbedTLS::create() {
return memnew(CryptoKeyMbedTLS);
}
Error CryptoKeyMbedTLS::load(String p_path) {
ERR_FAIL_COND_V_MSG(locks, ERR_ALREADY_IN_USE, "Key is in use");
PoolByteArray out;
FileAccess *f = FileAccess::open(p_path, FileAccess::READ);
ERR_FAIL_COND_V_MSG(!f, ERR_INVALID_PARAMETER, "Cannot open CryptoKeyMbedTLS file '" + p_path + "'.");
int flen = f->get_len();
out.resize(flen + 1);
{
PoolByteArray::Write w = out.write();
f->get_buffer(w.ptr(), flen);
w[flen] = 0; //end f string
}
memdelete(f);
int ret = mbedtls_pk_parse_key(&pkey, out.read().ptr(), out.size(), NULL, 0);
// We MUST zeroize the memory for safety!
mbedtls_platform_zeroize(out.write().ptr(), out.size());
ERR_FAIL_COND_V_MSG(ret, FAILED, "Error parsing private key '" + itos(ret) + "'.");
return OK;
}
Error CryptoKeyMbedTLS::save(String p_path) {
FileAccess *f = FileAccess::open(p_path, FileAccess::WRITE);
ERR_FAIL_COND_V_MSG(!f, ERR_INVALID_PARAMETER, "Cannot save CryptoKeyMbedTLS file '" + p_path + "'.");
unsigned char w[16000];
memset(w, 0, sizeof(w));
int ret = mbedtls_pk_write_key_pem(&pkey, w, sizeof(w));
if (ret != 0) {
memdelete(f);
memset(w, 0, sizeof(w)); // Zeroize anything we might have written.
ERR_FAIL_V_MSG(FAILED, "Error writing key '" + itos(ret) + "'.");
}
size_t len = strlen((char *)w);
f->store_buffer(w, len);
memdelete(f);
memset(w, 0, sizeof(w)); // Zeroize temporary buffer.
return OK;
}
X509Certificate *X509CertificateMbedTLS::create() {
return memnew(X509CertificateMbedTLS);
}
Error X509CertificateMbedTLS::load(String p_path) {
ERR_FAIL_COND_V_MSG(locks, ERR_ALREADY_IN_USE, "Certificate is in use");
PoolByteArray out;
FileAccess *f = FileAccess::open(p_path, FileAccess::READ);
ERR_FAIL_COND_V_MSG(!f, ERR_INVALID_PARAMETER, "Cannot open X509CertificateMbedTLS file '" + p_path + "'.");
int flen = f->get_len();
out.resize(flen + 1);
{
PoolByteArray::Write w = out.write();
f->get_buffer(w.ptr(), flen);
w[flen] = 0; //end f string
}
memdelete(f);
int ret = mbedtls_x509_crt_parse(&cert, out.read().ptr(), out.size());
ERR_FAIL_COND_V_MSG(ret, FAILED, "Error parsing some certificates: " + itos(ret));
return OK;
}
Error X509CertificateMbedTLS::load_from_memory(const uint8_t *p_buffer, int p_len) {
ERR_FAIL_COND_V_MSG(locks, ERR_ALREADY_IN_USE, "Certificate is in use");
int ret = mbedtls_x509_crt_parse(&cert, p_buffer, p_len);
ERR_FAIL_COND_V_MSG(ret, FAILED, "Error parsing certificates: " + itos(ret));
return OK;
}
Error X509CertificateMbedTLS::save(String p_path) {
FileAccess *f = FileAccess::open(p_path, FileAccess::WRITE);
ERR_FAIL_COND_V_MSG(!f, ERR_INVALID_PARAMETER, "Cannot save X509CertificateMbedTLS file '" + p_path + "'.");
mbedtls_x509_crt *crt = &cert;
while (crt) {
unsigned char w[4096];
size_t wrote = 0;
int ret = mbedtls_pem_write_buffer(PEM_BEGIN_CRT, PEM_END_CRT, cert.raw.p, cert.raw.len, w, sizeof(w), &wrote);
if (ret != 0 || wrote == 0) {
memdelete(f);
ERR_FAIL_V_MSG(FAILED, "Error writing certificate '" + itos(ret) + "'.");
}
f->store_buffer(w, wrote - 1); // don't write the string terminator
crt = crt->next;
}
memdelete(f);
return OK;
}
Crypto *CryptoMbedTLS::create() {
return memnew(CryptoMbedTLS);
}
void CryptoMbedTLS::initialize_crypto() {
#ifdef DEBUG_ENABLED
mbedtls_debug_set_threshold(1);
#endif
Crypto::_create = create;
Crypto::_load_default_certificates = load_default_certificates;
X509CertificateMbedTLS::make_default();
CryptoKeyMbedTLS::make_default();
}
void CryptoMbedTLS::finalize_crypto() {
Crypto::_create = NULL;
Crypto::_load_default_certificates = NULL;
if (default_certs) {
memdelete(default_certs);
default_certs = NULL;
}
X509CertificateMbedTLS::finalize();
CryptoKeyMbedTLS::finalize();
}
CryptoMbedTLS::CryptoMbedTLS() {
mbedtls_ctr_drbg_init(&ctr_drbg);
mbedtls_entropy_init(&entropy);
int ret = mbedtls_ctr_drbg_seed(&ctr_drbg, mbedtls_entropy_func, &entropy, NULL, 0);
if (ret != 0) {
ERR_PRINTS(" failed\n ! mbedtls_ctr_drbg_seed returned an error" + itos(ret));
}
}
CryptoMbedTLS::~CryptoMbedTLS() {
mbedtls_ctr_drbg_free(&ctr_drbg);
mbedtls_entropy_free(&entropy);
}
X509CertificateMbedTLS *CryptoMbedTLS::default_certs = NULL;
X509CertificateMbedTLS *CryptoMbedTLS::get_default_certificates() {
return default_certs;
}
void CryptoMbedTLS::load_default_certificates(String p_path) {
ERR_FAIL_COND(default_certs != NULL);
default_certs = memnew(X509CertificateMbedTLS);
ERR_FAIL_COND(default_certs == NULL);
String certs_path = GLOBAL_DEF("network/ssl/certificates", "");
if (p_path != "") {
// Use certs defined in project settings.
default_certs->load(p_path);
}
#ifdef BUILTIN_CERTS_ENABLED
else {
// Use builtin certs only if user did not override it in project settings.
PoolByteArray out;
out.resize(_certs_uncompressed_size + 1);
PoolByteArray::Write w = out.write();
Compression::decompress(w.ptr(), _certs_uncompressed_size, _certs_compressed, _certs_compressed_size, Compression::MODE_DEFLATE);
w[_certs_uncompressed_size] = 0; // Make sure it ends with string terminator
#ifdef DEBUG_ENABLED
print_verbose("Loaded builtin certs");
#endif
default_certs->load_from_memory(out.read().ptr(), out.size());
}
#endif
}
Ref<CryptoKey> CryptoMbedTLS::generate_rsa(int p_bytes) {
Ref<CryptoKeyMbedTLS> out;
out.instance();
int ret = mbedtls_pk_setup(&(out->pkey), mbedtls_pk_info_from_type(MBEDTLS_PK_RSA));
ERR_FAIL_COND_V(ret != 0, NULL);
ret = mbedtls_rsa_gen_key(mbedtls_pk_rsa(out->pkey), mbedtls_ctr_drbg_random, &ctr_drbg, p_bytes, 65537);
ERR_FAIL_COND_V(ret != 0, NULL);
return out;
}
Ref<X509Certificate> CryptoMbedTLS::generate_self_signed_certificate(Ref<CryptoKey> p_key, String p_issuer_name, String p_not_before, String p_not_after) {
Ref<CryptoKeyMbedTLS> key = static_cast<Ref<CryptoKeyMbedTLS> >(p_key);
ERR_FAIL_COND_V_MSG(key.is_null(), NULL, "Invalid private key argument.");
mbedtls_x509write_cert crt;
mbedtls_x509write_crt_init(&crt);
mbedtls_x509write_crt_set_subject_key(&crt, &(key->pkey));
mbedtls_x509write_crt_set_issuer_key(&crt, &(key->pkey));
mbedtls_x509write_crt_set_subject_name(&crt, p_issuer_name.utf8().get_data());
mbedtls_x509write_crt_set_issuer_name(&crt, p_issuer_name.utf8().get_data());
mbedtls_x509write_crt_set_version(&crt, MBEDTLS_X509_CRT_VERSION_3);
mbedtls_x509write_crt_set_md_alg(&crt, MBEDTLS_MD_SHA256);
mbedtls_mpi serial;
mbedtls_mpi_init(&serial);
uint8_t rand_serial[20];
mbedtls_ctr_drbg_random(&ctr_drbg, rand_serial, 20);
ERR_FAIL_COND_V(mbedtls_mpi_read_binary(&serial, rand_serial, 20), NULL);
mbedtls_x509write_crt_set_serial(&crt, &serial);
mbedtls_x509write_crt_set_validity(&crt, p_not_before.utf8().get_data(), p_not_after.utf8().get_data());
mbedtls_x509write_crt_set_basic_constraints(&crt, 1, -1);
mbedtls_x509write_crt_set_basic_constraints(&crt, 1, 0);
unsigned char buf[4096];
memset(buf, 0, 4096);
Ref<X509CertificateMbedTLS> out;
out.instance();
mbedtls_x509write_crt_pem(&crt, buf, 4096, mbedtls_ctr_drbg_random, &ctr_drbg);
int err = mbedtls_x509_crt_parse(&(out->cert), buf, 4096);
if (err != 0) {
mbedtls_mpi_free(&serial);
mbedtls_x509write_crt_free(&crt);
ERR_PRINTS("Generated invalid certificate: " + itos(err));
return NULL;
}
mbedtls_mpi_free(&serial);
mbedtls_x509write_crt_free(&crt);
return out;
}
PoolByteArray CryptoMbedTLS::generate_random_bytes(int p_bytes) {
PoolByteArray out;
out.resize(p_bytes);
mbedtls_ctr_drbg_random(&ctr_drbg, out.write().ptr(), p_bytes);
return out;
}