/*
* Copyright 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "keymaster1_engine.h"
#include <assert.h>
#include <algorithm>
#include <memory>
#define LOG_TAG "Keymaster1Engine"
#include <cutils/log.h>
#include "keymaster/android_keymaster_utils.h"
#include <openssl/bn.h>
#include <openssl/ec_key.h>
#include <openssl/ecdsa.h>
#include "openssl_err.h"
#include "openssl_utils.h"
using std::shared_ptr;
using std::unique_ptr;
namespace keymaster {
Keymaster1Engine* Keymaster1Engine::instance_ = nullptr;
Keymaster1Engine::Keymaster1Engine(const keymaster1_device_t* keymaster1_device)
: keymaster1_device_(keymaster1_device), engine_(ENGINE_new()),
rsa_index_(RSA_get_ex_new_index(0 /* argl */, NULL /* argp */, NULL /* new_func */,
Keymaster1Engine::duplicate_key_data,
Keymaster1Engine::free_key_data)),
ec_key_index_(EC_KEY_get_ex_new_index(0 /* argl */, NULL /* argp */, NULL /* new_func */,
Keymaster1Engine::duplicate_key_data,
Keymaster1Engine::free_key_data)),
rsa_method_(BuildRsaMethod()), ecdsa_method_(BuildEcdsaMethod()) {
assert(rsa_index_ != -1);
assert(ec_key_index_ != -1);
assert(keymaster1_device);
assert(!instance_);
instance_ = this;
ENGINE_set_RSA_method(engine_.get(), &rsa_method_, sizeof(rsa_method_));
ENGINE_set_ECDSA_method(engine_.get(), &ecdsa_method_, sizeof(ecdsa_method_));
}
Keymaster1Engine::~Keymaster1Engine() {
keymaster1_device_->common.close(
reinterpret_cast<hw_device_t*>(const_cast<keymaster1_device_t*>(keymaster1_device_)));
instance_ = nullptr;
}
static void ConvertCharacteristics(keymaster_key_characteristics_t* characteristics,
AuthorizationSet* hw_enforced, AuthorizationSet* sw_enforced) {
unique_ptr<keymaster_key_characteristics_t, Characteristics_Delete> characteristics_deleter(
characteristics);
if (hw_enforced)
hw_enforced->Reinitialize(characteristics->hw_enforced);
if (sw_enforced)
sw_enforced->Reinitialize(characteristics->sw_enforced);
}
keymaster_error_t Keymaster1Engine::GenerateKey(const AuthorizationSet& key_description,
KeymasterKeyBlob* key_blob,
AuthorizationSet* hw_enforced,
AuthorizationSet* sw_enforced) const {
assert(key_blob);
keymaster_key_characteristics_t* characteristics;
keymaster_key_blob_t blob;
keymaster_error_t error = keymaster1_device_->generate_key(keymaster1_device_, &key_description,
&blob, &characteristics);
if (error != KM_ERROR_OK)
return error;
unique_ptr<uint8_t, Malloc_Delete> blob_deleter(const_cast<uint8_t*>(blob.key_material));
key_blob->key_material = dup_buffer(blob.key_material, blob.key_material_size);
key_blob->key_material_size = blob.key_material_size;
ConvertCharacteristics(characteristics, hw_enforced, sw_enforced);
return error;
}
keymaster_error_t Keymaster1Engine::ImportKey(const AuthorizationSet& key_description,
keymaster_key_format_t input_key_material_format,
const KeymasterKeyBlob& input_key_material,
KeymasterKeyBlob* output_key_blob,
AuthorizationSet* hw_enforced,
AuthorizationSet* sw_enforced) const {
assert(output_key_blob);
keymaster_key_characteristics_t* characteristics;
const keymaster_blob_t input_key = {input_key_material.key_material,
input_key_material.key_material_size};
keymaster_key_blob_t blob;
keymaster_error_t error = keymaster1_device_->import_key(keymaster1_device_, &key_description,
input_key_material_format, &input_key,
&blob, &characteristics);
if (error != KM_ERROR_OK)
return error;
unique_ptr<uint8_t, Malloc_Delete> blob_deleter(const_cast<uint8_t*>(blob.key_material));
output_key_blob->key_material = dup_buffer(blob.key_material, blob.key_material_size);
output_key_blob->key_material_size = blob.key_material_size;
ConvertCharacteristics(characteristics, hw_enforced, sw_enforced);
return error;
}
keymaster_error_t Keymaster1Engine::DeleteKey(const KeymasterKeyBlob& blob) const {
if (!keymaster1_device_->delete_key)
return KM_ERROR_OK;
return keymaster1_device_->delete_key(keymaster1_device_, &blob);
}
keymaster_error_t Keymaster1Engine::DeleteAllKeys() const {
if (!keymaster1_device_->delete_all_keys)
return KM_ERROR_OK;
return keymaster1_device_->delete_all_keys(keymaster1_device_);
}
RSA* Keymaster1Engine::BuildRsaKey(const KeymasterKeyBlob& blob,
const AuthorizationSet& additional_params,
keymaster_error_t* error) const {
// Create new RSA key (with engine methods) and add metadata
unique_ptr<RSA, RSA_Delete> rsa(RSA_new_method(engine_.get()));
if (!rsa) {
*error = TranslateLastOpenSslError();
return nullptr;
}
KeyData* key_data = new KeyData(blob, additional_params);
if (!RSA_set_ex_data(rsa.get(), rsa_index_, key_data)) {
*error = TranslateLastOpenSslError();
delete key_data;
return nullptr;
}
// Copy public key into new RSA key
unique_ptr<EVP_PKEY, EVP_PKEY_Delete> pkey(
GetKeymaster1PublicKey(key_data->key_material, key_data->begin_params, error));
if (!pkey) {
*error = TranslateLastOpenSslError();
return nullptr;
}
unique_ptr<RSA, RSA_Delete> public_rsa(EVP_PKEY_get1_RSA(pkey.get()));
if (!public_rsa) {
*error = TranslateLastOpenSslError();
return nullptr;
}
rsa->n = BN_dup(public_rsa->n);
rsa->e = BN_dup(public_rsa->e);
if (!rsa->n || !rsa->e) {
*error = TranslateLastOpenSslError();
return nullptr;
}
*error = KM_ERROR_OK;
return rsa.release();
}
EC_KEY* Keymaster1Engine::BuildEcKey(const KeymasterKeyBlob& blob,
const AuthorizationSet& additional_params,
keymaster_error_t* error) const {
// Create new EC key (with engine methods) and insert blob
unique_ptr<EC_KEY, EC_KEY_Delete> ec_key(EC_KEY_new_method(engine_.get()));
if (!ec_key) {
*error = TranslateLastOpenSslError();
return nullptr;
}
KeyData* key_data = new KeyData(blob, additional_params);
if (!EC_KEY_set_ex_data(ec_key.get(), ec_key_index_, key_data)) {
*error = TranslateLastOpenSslError();
delete key_data;
return nullptr;
}
// Copy public key into new EC key
unique_ptr<EVP_PKEY, EVP_PKEY_Delete> pkey(
GetKeymaster1PublicKey(blob, additional_params, error));
if (!pkey) {
*error = TranslateLastOpenSslError();
return nullptr;
}
unique_ptr<EC_KEY, EC_KEY_Delete> public_ec_key(EVP_PKEY_get1_EC_KEY(pkey.get()));
if (!public_ec_key) {
*error = TranslateLastOpenSslError();
return nullptr;
}
if (!EC_KEY_set_group(ec_key.get(), EC_KEY_get0_group(public_ec_key.get())) ||
!EC_KEY_set_public_key(ec_key.get(), EC_KEY_get0_public_key(public_ec_key.get()))) {
*error = TranslateLastOpenSslError();
return nullptr;
}
*error = KM_ERROR_OK;
return ec_key.release();
}
Keymaster1Engine::KeyData* Keymaster1Engine::GetData(EVP_PKEY* key) const {
switch (EVP_PKEY_type(key->type)) {
case EVP_PKEY_RSA: {
unique_ptr<RSA, RSA_Delete> rsa(EVP_PKEY_get1_RSA(key));
return GetData(rsa.get());
}
case EVP_PKEY_EC: {
unique_ptr<EC_KEY, EC_KEY_Delete> ec_key(EVP_PKEY_get1_EC_KEY(key));
return GetData(ec_key.get());
}
default:
return nullptr;
};
}
Keymaster1Engine::KeyData* Keymaster1Engine::GetData(const RSA* rsa) const {
if (!rsa)
return nullptr;
return reinterpret_cast<KeyData*>(RSA_get_ex_data(rsa, rsa_index_));
}
Keymaster1Engine::KeyData* Keymaster1Engine::GetData(const EC_KEY* ec_key) const {
if (!ec_key)
return nullptr;
return reinterpret_cast<KeyData*>(EC_KEY_get_ex_data(ec_key, ec_key_index_));
}
/* static */
int Keymaster1Engine::duplicate_key_data(CRYPTO_EX_DATA* /* to */, const CRYPTO_EX_DATA* /* from */,
void** from_d, int /* index */, long /* argl */,
void* /* argp */) {
KeyData* data = reinterpret_cast<KeyData*>(*from_d);
if (!data)
return 1;
// Default copy ctor is good.
*from_d = new KeyData(*data);
if (*from_d)
return 1;
return 0;
}
/* static */
void Keymaster1Engine::free_key_data(void* /* parent */, void* ptr, CRYPTO_EX_DATA* /* data */,
int /* index*/, long /* argl */, void* /* argp */) {
delete reinterpret_cast<KeyData*>(ptr);
}
keymaster_error_t Keymaster1Engine::Keymaster1Finish(const KeyData* key_data,
const keymaster_blob_t& input,
keymaster_blob_t* output) {
if (key_data->op_handle == 0)
return KM_ERROR_UNKNOWN_ERROR;
size_t input_consumed;
// Note: devices are required to consume all input in a single update call for undigested
// signing operations and encryption operations. No need to loop here.
keymaster_error_t error =
device()->update(device(), key_data->op_handle, &key_data->finish_params, &input,
&input_consumed, nullptr /* out_params */, nullptr /* output */);
if (error != KM_ERROR_OK)
return error;
return device()->finish(device(), key_data->op_handle, &key_data->finish_params,
nullptr /* signature */, nullptr /* out_params */, output);
}
/* static */
int Keymaster1Engine::rsa_sign_raw(RSA* rsa, size_t* out_len, uint8_t* out, size_t max_out,
const uint8_t* in, size_t in_len, int padding) {
KeyData* key_data = instance_->GetData(rsa);
if (!key_data)
return 0;
if (padding != key_data->expected_openssl_padding) {
LOG_E("Expected sign_raw with padding %d but got padding %d",
key_data->expected_openssl_padding, padding);
return KM_ERROR_UNKNOWN_ERROR;
}
keymaster_blob_t input = {in, in_len};
keymaster_blob_t output;
key_data->error = instance_->Keymaster1Finish(key_data, input, &output);
if (key_data->error != KM_ERROR_OK)
return 0;
unique_ptr<uint8_t, Malloc_Delete> output_deleter(const_cast<uint8_t*>(output.data));
*out_len = std::min(output.data_length, max_out);
memcpy(out, output.data, *out_len);
return 1;
}
/* static */
int Keymaster1Engine::rsa_decrypt(RSA* rsa, size_t* out_len, uint8_t* out, size_t max_out,
const uint8_t* in, size_t in_len, int padding) {
KeyData* key_data = instance_->GetData(rsa);
if (!key_data)
return 0;
if (padding != key_data->expected_openssl_padding) {
LOG_E("Expected sign_raw with padding %d but got padding %d",
key_data->expected_openssl_padding, padding);
return KM_ERROR_UNKNOWN_ERROR;
}
keymaster_blob_t input = {in, in_len};
keymaster_blob_t output;
key_data->error = instance_->Keymaster1Finish(key_data, input, &output);
if (key_data->error != KM_ERROR_OK)
return 0;
unique_ptr<uint8_t, Malloc_Delete> output_deleter(const_cast<uint8_t*>(output.data));
*out_len = std::min(output.data_length, max_out);
memcpy(out, output.data, *out_len);
return 1;
}
/* static */
int Keymaster1Engine::ecdsa_sign(const uint8_t* digest, size_t digest_len, uint8_t* sig,
unsigned int* sig_len, EC_KEY* ec_key) {
KeyData* key_data = instance_->GetData(ec_key);
if (!key_data)
return 0;
// Truncate digest if it's too long
size_t max_input_len = (ec_group_size_bits(ec_key) + 7) / 8;
if (digest_len > max_input_len)
digest_len = max_input_len;
keymaster_blob_t input = {digest, digest_len};
keymaster_blob_t output;
key_data->error = instance_->Keymaster1Finish(key_data, input, &output);
if (key_data->error != KM_ERROR_OK)
return 0;
unique_ptr<uint8_t, Malloc_Delete> output_deleter(const_cast<uint8_t*>(output.data));
*sig_len = std::min(output.data_length, ECDSA_size(ec_key));
memcpy(sig, output.data, *sig_len);
return 1;
}
EVP_PKEY* Keymaster1Engine::GetKeymaster1PublicKey(const KeymasterKeyBlob& blob,
const AuthorizationSet& additional_params,
keymaster_error_t* error) const {
keymaster_blob_t client_id = {nullptr, 0};
keymaster_blob_t app_data = {nullptr, 0};
keymaster_blob_t* client_id_ptr = nullptr;
keymaster_blob_t* app_data_ptr = nullptr;
if (additional_params.GetTagValue(TAG_APPLICATION_ID, &client_id))
client_id_ptr = &client_id;
if (additional_params.GetTagValue(TAG_APPLICATION_DATA, &app_data))
app_data_ptr = &app_data;
keymaster_blob_t export_data = {nullptr, 0};
*error = keymaster1_device_->export_key(keymaster1_device_, KM_KEY_FORMAT_X509, &blob,
client_id_ptr, app_data_ptr, &export_data);
if (*error != KM_ERROR_OK)
return nullptr;
unique_ptr<uint8_t, Malloc_Delete> pub_key(const_cast<uint8_t*>(export_data.data));
const uint8_t* p = export_data.data;
return d2i_PUBKEY(nullptr /* allocate new struct */, &p, export_data.data_length);
}
RSA_METHOD Keymaster1Engine::BuildRsaMethod() {
RSA_METHOD method;
method.common.references = 0;
method.common.is_static = 1;
method.app_data = nullptr;
method.init = nullptr;
method.finish = nullptr;
method.size = nullptr;
method.sign = nullptr;
method.verify = nullptr;
method.encrypt = nullptr;
method.sign_raw = Keymaster1Engine::rsa_sign_raw;
method.decrypt = Keymaster1Engine::rsa_decrypt;
method.verify_raw = nullptr;
method.private_transform = nullptr;
method.mod_exp = nullptr;
method.bn_mod_exp = BN_mod_exp_mont;
method.flags = RSA_FLAG_OPAQUE;
method.keygen = nullptr;
method.supports_digest = nullptr;
return method;
}
ECDSA_METHOD Keymaster1Engine::BuildEcdsaMethod() {
ECDSA_METHOD method;
method.common.references = 0;
method.common.is_static = 1;
method.app_data = nullptr;
method.init = nullptr;
method.finish = nullptr;
method.group_order_size = nullptr;
method.sign = Keymaster1Engine::ecdsa_sign;
method.verify = nullptr;
method.flags = ECDSA_FLAG_OPAQUE;
return method;
}
} // namespace keymaster