godot/modules/mbedtls/crypto_mbedtls.cpp
2021-05-25 11:54:28 +01:00

452 lines
17 KiB
C++

/*************************************************************************/
/* crypto_mbedtls.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2021 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/config/engine.h"
#include "core/config/project_settings.h"
#include "core/io/certs_compressed.gen.h"
#include "core/io/compression.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/debug.h>
#include <mbedtls/md.h>
#include <mbedtls/pem.h>
CryptoKey *CryptoKeyMbedTLS::create() {
return memnew(CryptoKeyMbedTLS);
}
Error CryptoKeyMbedTLS::load(String p_path, bool p_public_only) {
ERR_FAIL_COND_V_MSG(locks, ERR_ALREADY_IN_USE, "Key is in use");
PackedByteArray out;
FileAccess *f = FileAccess::open(p_path, FileAccess::READ);
ERR_FAIL_COND_V_MSG(!f, ERR_INVALID_PARAMETER, "Cannot open CryptoKeyMbedTLS file '" + p_path + "'.");
uint64_t flen = f->get_length();
out.resize(flen + 1);
f->get_buffer(out.ptrw(), flen);
out.write[flen] = 0; // string terminator
memdelete(f);
int ret = 0;
if (p_public_only) {
ret = mbedtls_pk_parse_public_key(&pkey, out.ptr(), out.size());
} else {
ret = mbedtls_pk_parse_key(&pkey, out.ptr(), out.size(), nullptr, 0);
}
// We MUST zeroize the memory for safety!
mbedtls_platform_zeroize(out.ptrw(), out.size());
ERR_FAIL_COND_V_MSG(ret, FAILED, "Error parsing key '" + itos(ret) + "'.");
public_only = p_public_only;
return OK;
}
Error CryptoKeyMbedTLS::save(String p_path, bool p_public_only) {
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 = 0;
if (p_public_only) {
ret = mbedtls_pk_write_pubkey_pem(&pkey, w, sizeof(w));
} else {
ret = mbedtls_pk_write_key_pem(&pkey, w, sizeof(w));
}
if (ret != 0) {
memdelete(f);
mbedtls_platform_zeroize(w, 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);
mbedtls_platform_zeroize(w, sizeof(w)); // Zeroize temporary buffer.
return OK;
}
Error CryptoKeyMbedTLS::load_from_string(String p_string_key, bool p_public_only) {
int ret = 0;
if (p_public_only) {
ret = mbedtls_pk_parse_public_key(&pkey, (unsigned char *)p_string_key.utf8().get_data(), p_string_key.utf8().size());
} else {
ret = mbedtls_pk_parse_key(&pkey, (unsigned char *)p_string_key.utf8().get_data(), p_string_key.utf8().size(), nullptr, 0);
}
ERR_FAIL_COND_V_MSG(ret, FAILED, "Error parsing key '" + itos(ret) + "'.");
public_only = p_public_only;
return OK;
}
String CryptoKeyMbedTLS::save_to_string(bool p_public_only) {
unsigned char w[16000];
memset(w, 0, sizeof(w));
int ret = 0;
if (p_public_only) {
ret = mbedtls_pk_write_pubkey_pem(&pkey, w, sizeof(w));
} else {
ret = mbedtls_pk_write_key_pem(&pkey, w, sizeof(w));
}
if (ret != 0) {
mbedtls_platform_zeroize(w, sizeof(w));
ERR_FAIL_V_MSG("", "Error saving key '" + itos(ret) + "'.");
}
String s = String::utf8((char *)w);
return s;
}
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");
PackedByteArray out;
FileAccess *f = FileAccess::open(p_path, FileAccess::READ);
ERR_FAIL_COND_V_MSG(!f, ERR_INVALID_PARAMETER, "Cannot open X509CertificateMbedTLS file '" + p_path + "'.");
uint64_t flen = f->get_length();
out.resize(flen + 1);
f->get_buffer(out.ptrw(), flen);
out.write[flen] = 0; // string terminator
memdelete(f);
int ret = mbedtls_x509_crt_parse(&cert, out.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;
}
bool HMACContextMbedTLS::is_md_type_allowed(mbedtls_md_type_t p_md_type) {
switch (p_md_type) {
case MBEDTLS_MD_SHA1:
case MBEDTLS_MD_SHA256:
return true;
default:
return false;
}
}
HMACContext *HMACContextMbedTLS::create() {
return memnew(HMACContextMbedTLS);
}
Error HMACContextMbedTLS::start(HashingContext::HashType p_hash_type, PackedByteArray p_key) {
ERR_FAIL_COND_V_MSG(ctx != nullptr, ERR_FILE_ALREADY_IN_USE, "HMACContext already started.");
// HMAC keys can be any size.
ERR_FAIL_COND_V_MSG(p_key.is_empty(), ERR_INVALID_PARAMETER, "Key must not be empty.");
hash_type = p_hash_type;
mbedtls_md_type_t ht = CryptoMbedTLS::md_type_from_hashtype(p_hash_type, hash_len);
bool allowed = HMACContextMbedTLS::is_md_type_allowed(ht);
ERR_FAIL_COND_V_MSG(!allowed, ERR_INVALID_PARAMETER, "Unsupported hash type.");
ctx = memalloc(sizeof(mbedtls_md_context_t));
mbedtls_md_init((mbedtls_md_context_t *)ctx);
mbedtls_md_setup((mbedtls_md_context_t *)ctx, mbedtls_md_info_from_type((mbedtls_md_type_t)ht), 1);
int ret = mbedtls_md_hmac_starts((mbedtls_md_context_t *)ctx, (const uint8_t *)p_key.ptr(), (size_t)p_key.size());
return ret ? FAILED : OK;
}
Error HMACContextMbedTLS::update(PackedByteArray p_data) {
ERR_FAIL_COND_V_MSG(ctx == nullptr, ERR_INVALID_DATA, "Start must be called before update.");
ERR_FAIL_COND_V_MSG(p_data.is_empty(), ERR_INVALID_PARAMETER, "Src must not be empty.");
int ret = mbedtls_md_hmac_update((mbedtls_md_context_t *)ctx, (const uint8_t *)p_data.ptr(), (size_t)p_data.size());
return ret ? FAILED : OK;
}
PackedByteArray HMACContextMbedTLS::finish() {
ERR_FAIL_COND_V_MSG(ctx == nullptr, PackedByteArray(), "Start must be called before finish.");
ERR_FAIL_COND_V_MSG(hash_len == 0, PackedByteArray(), "Unsupported hash type.");
PackedByteArray out;
out.resize(hash_len);
unsigned char *out_ptr = (unsigned char *)out.ptrw();
int ret = mbedtls_md_hmac_finish((mbedtls_md_context_t *)ctx, out_ptr);
mbedtls_md_free((mbedtls_md_context_t *)ctx);
memfree((mbedtls_md_context_t *)ctx);
ctx = nullptr;
hash_len = 0;
ERR_FAIL_COND_V_MSG(ret, PackedByteArray(), "Error received while finishing HMAC");
return out;
}
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();
HMACContextMbedTLS::make_default();
}
void CryptoMbedTLS::finalize_crypto() {
Crypto::_create = nullptr;
Crypto::_load_default_certificates = nullptr;
if (default_certs) {
memdelete(default_certs);
default_certs = nullptr;
}
X509CertificateMbedTLS::finalize();
CryptoKeyMbedTLS::finalize();
HMACContextMbedTLS::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, nullptr, 0);
if (ret != 0) {
ERR_PRINT(" 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 = nullptr;
X509CertificateMbedTLS *CryptoMbedTLS::get_default_certificates() {
return default_certs;
}
void CryptoMbedTLS::load_default_certificates(String p_path) {
ERR_FAIL_COND(default_certs != nullptr);
default_certs = memnew(X509CertificateMbedTLS);
ERR_FAIL_COND(default_certs == nullptr);
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.
PackedByteArray out;
out.resize(_certs_uncompressed_size + 1);
Compression::decompress(out.ptrw(), _certs_uncompressed_size, _certs_compressed, _certs_compressed_size, Compression::MODE_DEFLATE);
out.write[_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.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, nullptr);
ret = mbedtls_rsa_gen_key(mbedtls_pk_rsa(out->pkey), mbedtls_ctr_drbg_random, &ctr_drbg, p_bytes, 65537);
out->public_only = false;
ERR_FAIL_COND_V(ret != 0, nullptr);
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(), nullptr, "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), nullptr);
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);
int ret = mbedtls_x509write_crt_pem(&crt, buf, 4096, mbedtls_ctr_drbg_random, &ctr_drbg);
mbedtls_mpi_free(&serial);
mbedtls_x509write_crt_free(&crt);
ERR_FAIL_COND_V_MSG(ret != 0, nullptr, "Failed to generate certificate: " + itos(ret));
buf[4095] = '\0'; // Make sure strlen can't fail.
Ref<X509CertificateMbedTLS> out;
out.instance();
out->load_from_memory(buf, strlen((char *)buf) + 1); // Use strlen to find correct output size.
return out;
}
PackedByteArray CryptoMbedTLS::generate_random_bytes(int p_bytes) {
PackedByteArray out;
out.resize(p_bytes);
mbedtls_ctr_drbg_random(&ctr_drbg, out.ptrw(), p_bytes);
return out;
}
mbedtls_md_type_t CryptoMbedTLS::md_type_from_hashtype(HashingContext::HashType p_hash_type, int &r_size) {
switch (p_hash_type) {
case HashingContext::HASH_MD5:
r_size = 16;
return MBEDTLS_MD_MD5;
case HashingContext::HASH_SHA1:
r_size = 20;
return MBEDTLS_MD_SHA1;
case HashingContext::HASH_SHA256:
r_size = 32;
return MBEDTLS_MD_SHA256;
default:
r_size = 0;
ERR_FAIL_V_MSG(MBEDTLS_MD_NONE, "Invalid hash type.");
}
}
Vector<uint8_t> CryptoMbedTLS::sign(HashingContext::HashType p_hash_type, Vector<uint8_t> p_hash, Ref<CryptoKey> p_key) {
int size;
mbedtls_md_type_t type = CryptoMbedTLS::md_type_from_hashtype(p_hash_type, size);
ERR_FAIL_COND_V_MSG(type == MBEDTLS_MD_NONE, Vector<uint8_t>(), "Invalid hash type.");
ERR_FAIL_COND_V_MSG(p_hash.size() != size, Vector<uint8_t>(), "Invalid hash provided. Size must be " + itos(size));
Ref<CryptoKeyMbedTLS> key = static_cast<Ref<CryptoKeyMbedTLS>>(p_key);
ERR_FAIL_COND_V_MSG(!key.is_valid(), Vector<uint8_t>(), "Invalid key provided.");
ERR_FAIL_COND_V_MSG(key->is_public_only(), Vector<uint8_t>(), "Invalid key provided. Cannot sign with public_only keys.");
size_t sig_size = 0;
unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
Vector<uint8_t> out;
int ret = mbedtls_pk_sign(&(key->pkey), type, p_hash.ptr(), size, buf, &sig_size, mbedtls_ctr_drbg_random, &ctr_drbg);
ERR_FAIL_COND_V_MSG(ret, out, "Error while signing: " + itos(ret));
out.resize(sig_size);
memcpy(out.ptrw(), buf, sig_size);
return out;
}
bool CryptoMbedTLS::verify(HashingContext::HashType p_hash_type, Vector<uint8_t> p_hash, Vector<uint8_t> p_signature, Ref<CryptoKey> p_key) {
int size;
mbedtls_md_type_t type = CryptoMbedTLS::md_type_from_hashtype(p_hash_type, size);
ERR_FAIL_COND_V_MSG(type == MBEDTLS_MD_NONE, false, "Invalid hash type.");
ERR_FAIL_COND_V_MSG(p_hash.size() != size, false, "Invalid hash provided. Size must be " + itos(size));
Ref<CryptoKeyMbedTLS> key = static_cast<Ref<CryptoKeyMbedTLS>>(p_key);
ERR_FAIL_COND_V_MSG(!key.is_valid(), false, "Invalid key provided.");
return mbedtls_pk_verify(&(key->pkey), type, p_hash.ptr(), size, p_signature.ptr(), p_signature.size()) == 0;
}
Vector<uint8_t> CryptoMbedTLS::encrypt(Ref<CryptoKey> p_key, Vector<uint8_t> p_plaintext) {
Ref<CryptoKeyMbedTLS> key = static_cast<Ref<CryptoKeyMbedTLS>>(p_key);
ERR_FAIL_COND_V_MSG(!key.is_valid(), Vector<uint8_t>(), "Invalid key provided.");
uint8_t buf[1024];
size_t size;
Vector<uint8_t> out;
int ret = mbedtls_pk_encrypt(&(key->pkey), p_plaintext.ptr(), p_plaintext.size(), buf, &size, sizeof(buf), mbedtls_ctr_drbg_random, &ctr_drbg);
ERR_FAIL_COND_V_MSG(ret, out, "Error while encrypting: " + itos(ret));
out.resize(size);
memcpy(out.ptrw(), buf, size);
return out;
}
Vector<uint8_t> CryptoMbedTLS::decrypt(Ref<CryptoKey> p_key, Vector<uint8_t> p_ciphertext) {
Ref<CryptoKeyMbedTLS> key = static_cast<Ref<CryptoKeyMbedTLS>>(p_key);
ERR_FAIL_COND_V_MSG(!key.is_valid(), Vector<uint8_t>(), "Invalid key provided.");
ERR_FAIL_COND_V_MSG(key->is_public_only(), Vector<uint8_t>(), "Invalid key provided. Cannot decrypt using a public_only key.");
uint8_t buf[2048];
size_t size;
Vector<uint8_t> out;
int ret = mbedtls_pk_decrypt(&(key->pkey), p_ciphertext.ptr(), p_ciphertext.size(), buf, &size, sizeof(buf), mbedtls_ctr_drbg_random, &ctr_drbg);
ERR_FAIL_COND_V_MSG(ret, out, "Error while decrypting: " + itos(ret));
out.resize(size);
memcpy(out.ptrw(), buf, size);
return out;
}