New CryptoMbedTLS Crypto implementation.

Allows random bytes, RSA keys, and X509 certificates generation.

3 files changed, 412 insertions, 1 deletions

diff --git a/modules/mbedtls/crypto_mbedtls.cpp b/modules/mbedtls/crypto_mbedtls.cpp
new file mode 100644
index 0000000000..9c8eb40ca4
--- /dev/null
+++ b/modules/mbedtls/crypto_mbedtls.cpp
@@ -0,0 +1,285 @@
+/*************************************************************************/
+/*  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.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#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(!f, ERR_INVALID_PARAMETER);
+
+	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 some certificates: " + itos(ret));
+
+	return OK;
+}
+
+Error CryptoKeyMbedTLS::save(String p_path) {
+	FileAccess *f = FileAccess::open(p_path, FileAccess::WRITE);
+	ERR_FAIL_COND_V(!f, ERR_INVALID_PARAMETER);
+
+	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(!f, ERR_INVALID_PARAMETER);
+
+	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(!f, ERR_INVALID_PARAMETER);
+
+	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);
+	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;
+}
diff --git a/modules/mbedtls/crypto_mbedtls.h b/modules/mbedtls/crypto_mbedtls.h
new file mode 100644
index 0000000000..06b3ecd234
--- /dev/null
+++ b/modules/mbedtls/crypto_mbedtls.h
@@ -0,0 +1,124 @@
+/*************************************************************************/
+/*  crypto_mbedtls.h                                                     */
+/*************************************************************************/
+/*                       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.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef CRYPTO_MBEDTLS_H
+#define CRYPTO_MBEDTLS_H
+
+#include "core/crypto/crypto.h"
+#include "core/resource.h"
+
+#include <mbedtls/ctr_drbg.h>
+#include <mbedtls/entropy.h>
+#include <mbedtls/ssl.h>
+
+class CryptoMbedTLS;
+class SSLContextMbedTLS;
+class CryptoKeyMbedTLS : public CryptoKey {
+
+private:
+	mbedtls_pk_context pkey;
+	int locks;
+
+public:
+	static CryptoKey *create();
+	static void make_default() { CryptoKey::_create = create; }
+	static void finalize() { CryptoKey::_create = NULL; }
+
+	virtual Error load(String p_path);
+	virtual Error save(String p_path);
+
+	CryptoKeyMbedTLS() {
+		mbedtls_pk_init(&pkey);
+		locks = 0;
+	}
+	~CryptoKeyMbedTLS() {
+		mbedtls_pk_free(&pkey);
+	}
+
+	_FORCE_INLINE_ void lock() { locks++; }
+	_FORCE_INLINE_ void unlock() { locks--; }
+
+	friend class CryptoMbedTLS;
+	friend class SSLContextMbedTLS;
+};
+
+class X509CertificateMbedTLS : public X509Certificate {
+
+private:
+	mbedtls_x509_crt cert;
+	int locks;
+
+public:
+	static X509Certificate *create();
+	static void make_default() { X509Certificate::_create = create; }
+	static void finalize() { X509Certificate::_create = NULL; }
+
+	virtual Error load(String p_path);
+	virtual Error load_from_memory(const uint8_t *p_buffer, int p_len);
+	virtual Error save(String p_path);
+
+	X509CertificateMbedTLS() {
+		mbedtls_x509_crt_init(&cert);
+		locks = 0;
+	}
+	~X509CertificateMbedTLS() {
+		mbedtls_x509_crt_free(&cert);
+	}
+
+	_FORCE_INLINE_ void lock() { locks++; }
+	_FORCE_INLINE_ void unlock() { locks--; }
+
+	friend class CryptoMbedTLS;
+	friend class SSLContextMbedTLS;
+};
+
+class CryptoMbedTLS : public Crypto {
+
+private:
+	mbedtls_entropy_context entropy;
+	mbedtls_ctr_drbg_context ctr_drbg;
+	static X509CertificateMbedTLS *default_certs;
+
+public:
+	static Crypto *create();
+	static void initialize_crypto();
+	static void finalize_crypto();
+	static X509CertificateMbedTLS *get_default_certificates();
+	static void load_default_certificates(String p_path);
+
+	virtual PoolByteArray generate_random_bytes(int p_bytes);
+	virtual Ref<CryptoKey> generate_rsa(int p_bytes);
+	virtual Ref<X509Certificate> generate_self_signed_certificate(Ref<CryptoKey> p_key, String p_issuer_name, String p_not_before, String p_not_after);
+
+	CryptoMbedTLS();
+	~CryptoMbedTLS();
+};
+
+#endif // CRYPTO_MBEDTLS_H
diff --git a/modules/mbedtls/register_types.cpp b/modules/mbedtls/register_types.cpp
index 121ed5eb02..88f8155336 100755
--- a/modules/mbedtls/register_types.cpp
+++ b/modules/mbedtls/register_types.cpp
@@ -30,15 +30,17 @@
 
 #include "register_types.h"
 
+#include "crypto_mbedtls.h"
 #include "stream_peer_mbed_tls.h"
 
 void register_mbedtls_types() {
 
-	ClassDB::register_class<StreamPeerMbedTLS>();
+	CryptoMbedTLS::initialize_crypto();
 	StreamPeerMbedTLS::initialize_ssl();
 }
 
 void unregister_mbedtls_types() {
 
 	StreamPeerMbedTLS::finalize_ssl();
+	CryptoMbedTLS::finalize_crypto();
 }