/*
* Copyright 2014 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.
*/
#define LOG_TAG "TrustyKeymaster"
#include <assert.h>
#include <openssl/evp.h>
#include <openssl/x509.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <type_traits>
#include <hardware/keymaster0.h>
#include <keymaster/authorization_set.h>
#include <log/log.h>
#include "trusty_keymaster_device.h"
#include "trusty_keymaster_ipc.h"
#include "keymaster_ipc.h"
const uint32_t SEND_BUF_SIZE = 8192;
const uint32_t RECV_BUF_SIZE = 8192;
namespace keymaster {
static keymaster_error_t translate_error(int err) {
switch (err) {
case 0:
return KM_ERROR_OK;
case -EPERM:
case -EACCES:
return KM_ERROR_SECURE_HW_ACCESS_DENIED;
case -ECANCELED:
return KM_ERROR_OPERATION_CANCELLED;
case -ENODEV:
return KM_ERROR_UNIMPLEMENTED;
case -ENOMEM:
return KM_ERROR_MEMORY_ALLOCATION_FAILED;
case -EBUSY:
return KM_ERROR_SECURE_HW_BUSY;
case -EIO:
return KM_ERROR_SECURE_HW_COMMUNICATION_FAILED;
case -EOVERFLOW:
return KM_ERROR_INVALID_INPUT_LENGTH;
default:
return KM_ERROR_UNKNOWN_ERROR;
}
}
TrustyKeymasterDevice::TrustyKeymasterDevice(const hw_module_t* module) {
static_assert(std::is_standard_layout<TrustyKeymasterDevice>::value,
"TrustyKeymasterDevice must be standard layout");
static_assert(offsetof(TrustyKeymasterDevice, device_) == 0,
"device_ must be the first member of KeymasterOpenSsl");
static_assert(offsetof(TrustyKeymasterDevice, device_.common) == 0,
"common must be the first member of keymaster_device");
ALOGI("Creating device");
ALOGD("Device address: %p", this);
memset(&device_, 0, sizeof(device_));
device_.common.tag = HARDWARE_DEVICE_TAG;
device_.common.version = 1;
device_.common.module = const_cast<hw_module_t*>(module);
device_.common.close = close_device;
device_.flags = KEYMASTER_BLOBS_ARE_STANDALONE | KEYMASTER_SUPPORTS_EC;
device_.generate_keypair = generate_keypair;
device_.import_keypair = import_keypair;
device_.get_keypair_public = get_keypair_public;
device_.delete_keypair = NULL;
device_.delete_all = NULL;
device_.sign_data = sign_data;
device_.verify_data = verify_data;
device_.context = NULL;
int rc = trusty_keymaster_connect();
error_ = translate_error(rc);
if (rc < 0) {
ALOGE("failed to connect to keymaster (%d)", rc);
return;
}
GetVersionRequest version_request;
GetVersionResponse version_response;
error_ = Send(version_request, &version_response);
if (error_ == KM_ERROR_INVALID_ARGUMENT || error_ == KM_ERROR_UNIMPLEMENTED) {
ALOGI("\"Bad parameters\" error on GetVersion call. Assuming version 0.");
message_version_ = 0;
error_ = KM_ERROR_OK;
}
message_version_ = MessageVersion(version_response.major_ver, version_response.minor_ver,
version_response.subminor_ver);
if (message_version_ < 0) {
// Can't translate version? Keymaster implementation must be newer.
ALOGE("Keymaster version %d.%d.%d not supported.", version_response.major_ver,
version_response.minor_ver, version_response.subminor_ver);
error_ = KM_ERROR_VERSION_MISMATCH;
}
}
TrustyKeymasterDevice::~TrustyKeymasterDevice() {
trusty_keymaster_disconnect();
}
const uint64_t HUNDRED_YEARS = 1000LL * 60 * 60 * 24 * 365 * 100;
int TrustyKeymasterDevice::generate_keypair(const keymaster_keypair_t key_type,
const void* key_params, uint8_t** key_blob,
size_t* key_blob_length) {
ALOGD("Device received generate_keypair");
if (error_ != KM_ERROR_OK)
return error_;
GenerateKeyRequest req(message_version_);
StoreNewKeyParams(&req.key_description);
switch (key_type) {
case TYPE_RSA: {
req.key_description.push_back(TAG_ALGORITHM, KM_ALGORITHM_RSA);
const keymaster_rsa_keygen_params_t* rsa_params =
static_cast<const keymaster_rsa_keygen_params_t*>(key_params);
ALOGD("Generating RSA pair, modulus size: %u, public exponent: %lu",
rsa_params->modulus_size, rsa_params->public_exponent);
req.key_description.push_back(TAG_KEY_SIZE, rsa_params->modulus_size);
req.key_description.push_back(TAG_RSA_PUBLIC_EXPONENT, rsa_params->public_exponent);
break;
}
case TYPE_EC: {
req.key_description.push_back(TAG_ALGORITHM, KM_ALGORITHM_EC);
const keymaster_ec_keygen_params_t* ec_params =
static_cast<const keymaster_ec_keygen_params_t*>(key_params);
ALOGD("Generating ECDSA pair, key size: %u", ec_params->field_size);
req.key_description.push_back(TAG_KEY_SIZE, ec_params->field_size);
break;
}
default:
ALOGD("Received request for unsuported key type %d", key_type);
return KM_ERROR_UNSUPPORTED_ALGORITHM;
}
GenerateKeyResponse rsp(message_version_);
ALOGD("Sending generate request");
keymaster_error_t err = Send(req, &rsp);
if (err != KM_ERROR_OK) {
ALOGE("Got error %d from send", err);
return err;
}
*key_blob_length = rsp.key_blob.key_material_size;
*key_blob = static_cast<uint8_t*>(malloc(*key_blob_length));
memcpy(*key_blob, rsp.key_blob.key_material, *key_blob_length);
ALOGD("Returning %d bytes in key blob\n", (int)*key_blob_length);
return KM_ERROR_OK;
}
struct EVP_PKEY_Delete {
void operator()(EVP_PKEY* p) const { EVP_PKEY_free(p); }
};
struct PKCS8_PRIV_KEY_INFO_Delete {
void operator()(PKCS8_PRIV_KEY_INFO* p) const { PKCS8_PRIV_KEY_INFO_free(p); }
};
int TrustyKeymasterDevice::import_keypair(const uint8_t* key, const size_t key_length,
uint8_t** key_blob, size_t* key_blob_length) {
ALOGD("Device received import_keypair");
if (error_ != KM_ERROR_OK)
return error_;
if (!key)
return KM_ERROR_UNEXPECTED_NULL_POINTER;
if (!key_blob || !key_blob_length)
return KM_ERROR_OUTPUT_PARAMETER_NULL;
ImportKeyRequest request(message_version_);
StoreNewKeyParams(&request.key_description);
keymaster_algorithm_t algorithm;
keymaster_error_t err = GetPkcs8KeyAlgorithm(key, key_length, &algorithm);
if (err != KM_ERROR_OK)
return err;
request.key_description.push_back(TAG_ALGORITHM, algorithm);
request.SetKeyMaterial(key, key_length);
request.key_format = KM_KEY_FORMAT_PKCS8;
ImportKeyResponse response(message_version_);
err = Send(request, &response);
if (err != KM_ERROR_OK)
return err;
*key_blob_length = response.key_blob.key_material_size;
*key_blob = static_cast<uint8_t*>(malloc(*key_blob_length));
memcpy(*key_blob, response.key_blob.key_material, *key_blob_length);
printf("Returning %d bytes in key blob\n", (int)*key_blob_length);
return KM_ERROR_OK;
}
keymaster_error_t TrustyKeymasterDevice::GetPkcs8KeyAlgorithm(const uint8_t* key, size_t key_length,
keymaster_algorithm_t* algorithm) {
if (key == NULL) {
ALOGE("No key specified for import");
return KM_ERROR_UNEXPECTED_NULL_POINTER;
}
UniquePtr<PKCS8_PRIV_KEY_INFO, PKCS8_PRIV_KEY_INFO_Delete> pkcs8(
d2i_PKCS8_PRIV_KEY_INFO(NULL, &key, key_length));
if (pkcs8.get() == NULL) {
ALOGE("Could not parse PKCS8 key blob");
return KM_ERROR_INVALID_KEY_BLOB;
}
UniquePtr<EVP_PKEY, EVP_PKEY_Delete> pkey(EVP_PKCS82PKEY(pkcs8.get()));
if (pkey.get() == NULL) {
ALOGE("Could not extract key from PKCS8 key blob");
return KM_ERROR_INVALID_KEY_BLOB;
}
switch (EVP_PKEY_type(pkey->type)) {
case EVP_PKEY_RSA:
*algorithm = KM_ALGORITHM_RSA;
break;
case EVP_PKEY_EC:
*algorithm = KM_ALGORITHM_EC;
break;
default:
ALOGE("Unsupported algorithm %d", EVP_PKEY_type(pkey->type));
return KM_ERROR_UNSUPPORTED_ALGORITHM;
}
return KM_ERROR_OK;
}
int TrustyKeymasterDevice::get_keypair_public(const uint8_t* key_blob, const size_t key_blob_length,
uint8_t** x509_data, size_t* x509_data_length) {
ALOGD("Device received get_keypair_public");
if (error_ != KM_ERROR_OK)
return error_;
ExportKeyRequest request(message_version_);
request.SetKeyMaterial(key_blob, key_blob_length);
request.key_format = KM_KEY_FORMAT_X509;
ExportKeyResponse response(message_version_);
keymaster_error_t err = Send(request, &response);
if (err != KM_ERROR_OK)
return err;
*x509_data_length = response.key_data_length;
*x509_data = static_cast<uint8_t*>(malloc(*x509_data_length));
memcpy(*x509_data, response.key_data, *x509_data_length);
printf("Returning %d bytes in x509 key\n", (int)*x509_data_length);
return KM_ERROR_OK;
}
int TrustyKeymasterDevice::sign_data(const void* signing_params, const uint8_t* key_blob,
const size_t key_blob_length, const uint8_t* data,
const size_t data_length, uint8_t** signed_data,
size_t* signed_data_length) {
ALOGD("Device received sign_data, %d", error_);
if (error_ != KM_ERROR_OK)
return error_;
BeginOperationRequest begin_request(message_version_);
begin_request.purpose = KM_PURPOSE_SIGN;
begin_request.SetKeyMaterial(key_blob, key_blob_length);
keymaster_error_t err = StoreSigningParams(signing_params, key_blob, key_blob_length,
&begin_request.additional_params);
if (err != KM_ERROR_OK) {
ALOGE("Error extracting signing params: %d", err);
return err;
}
BeginOperationResponse begin_response(message_version_);
ALOGD("Sending signing request begin");
err = Send(begin_request, &begin_response);
if (err != KM_ERROR_OK) {
ALOGE("Error sending sign begin: %d", err);
return err;
}
UpdateOperationRequest update_request(message_version_);
update_request.op_handle = begin_response.op_handle;
update_request.input.Reinitialize(data, data_length);
UpdateOperationResponse update_response(message_version_);
ALOGD("Sending signing request update");
err = Send(update_request, &update_response);
if (err != KM_ERROR_OK) {
ALOGE("Error sending sign update: %d", err);
return err;
}
FinishOperationRequest finish_request(message_version_);
finish_request.op_handle = begin_response.op_handle;
FinishOperationResponse finish_response(message_version_);
ALOGD("Sending signing request finish");
err = Send(finish_request, &finish_response);
if (err != KM_ERROR_OK) {
ALOGE("Error sending sign finish: %d", err);
return err;
}
*signed_data_length = finish_response.output.available_read();
*signed_data = static_cast<uint8_t*>(malloc(*signed_data_length));
if (!finish_response.output.read(*signed_data, *signed_data_length)) {
ALOGE("Error reading response data: %d", err);
return KM_ERROR_UNKNOWN_ERROR;
}
return KM_ERROR_OK;
}
int TrustyKeymasterDevice::verify_data(const void* signing_params, const uint8_t* key_blob,
const size_t key_blob_length, const uint8_t* signed_data,
const size_t signed_data_length, const uint8_t* signature,
const size_t signature_length) {
ALOGD("Device received verify_data");
if (error_ != KM_ERROR_OK)
return error_;
BeginOperationRequest begin_request(message_version_);
begin_request.purpose = KM_PURPOSE_VERIFY;
begin_request.SetKeyMaterial(key_blob, key_blob_length);
keymaster_error_t err = StoreSigningParams(signing_params, key_blob, key_blob_length,
&begin_request.additional_params);
if (err != KM_ERROR_OK)
return err;
BeginOperationResponse begin_response(message_version_);
err = Send(begin_request, &begin_response);
if (err != KM_ERROR_OK)
return err;
UpdateOperationRequest update_request(message_version_);
update_request.op_handle = begin_response.op_handle;
update_request.input.Reinitialize(signed_data, signed_data_length);
UpdateOperationResponse update_response(message_version_);
err = Send(update_request, &update_response);
if (err != KM_ERROR_OK)
return err;
FinishOperationRequest finish_request(message_version_);
finish_request.op_handle = begin_response.op_handle;
finish_request.signature.Reinitialize(signature, signature_length);
FinishOperationResponse finish_response(message_version_);
err = Send(finish_request, &finish_response);
if (err != KM_ERROR_OK)
return err;
return KM_ERROR_OK;
}
hw_device_t* TrustyKeymasterDevice::hw_device() {
return &device_.common;
}
static inline TrustyKeymasterDevice* convert_device(const keymaster0_device_t* dev) {
return reinterpret_cast<TrustyKeymasterDevice*>(const_cast<keymaster0_device_t*>(dev));
}
/* static */
int TrustyKeymasterDevice::close_device(hw_device_t* dev) {
delete reinterpret_cast<TrustyKeymasterDevice*>(dev);
return 0;
}
/* static */
int TrustyKeymasterDevice::generate_keypair(const keymaster0_device_t* dev,
const keymaster_keypair_t key_type,
const void* key_params, uint8_t** keyBlob,
size_t* keyBlobLength) {
ALOGD("Generate keypair, sending to device: %p", convert_device(dev));
return convert_device(dev)->generate_keypair(key_type, key_params, keyBlob, keyBlobLength);
}
/* static */
int TrustyKeymasterDevice::import_keypair(const keymaster0_device_t* dev, const uint8_t* key,
const size_t key_length, uint8_t** key_blob,
size_t* key_blob_length) {
return convert_device(dev)->import_keypair(key, key_length, key_blob, key_blob_length);
}
/* static */
int TrustyKeymasterDevice::get_keypair_public(const keymaster0_device_t* dev,
const uint8_t* key_blob, const size_t key_blob_length,
uint8_t** x509_data, size_t* x509_data_length) {
return convert_device(dev)
->get_keypair_public(key_blob, key_blob_length, x509_data, x509_data_length);
}
/* static */
int TrustyKeymasterDevice::sign_data(const keymaster0_device_t* dev, const void* params,
const uint8_t* keyBlob, const size_t keyBlobLength,
const uint8_t* data, const size_t dataLength,
uint8_t** signedData, size_t* signedDataLength) {
return convert_device(dev)
->sign_data(params, keyBlob, keyBlobLength, data, dataLength, signedData, signedDataLength);
}
/* static */
int TrustyKeymasterDevice::verify_data(const keymaster0_device_t* dev, const void* params,
const uint8_t* keyBlob, const size_t keyBlobLength,
const uint8_t* signedData, const size_t signedDataLength,
const uint8_t* signature, const size_t signatureLength) {
return convert_device(dev)->verify_data(params, keyBlob, keyBlobLength, signedData,
signedDataLength, signature, signatureLength);
}
keymaster_error_t TrustyKeymasterDevice::Send(uint32_t command, const Serializable& req,
KeymasterResponse* rsp) {
uint32_t req_size = req.SerializedSize();
if (req_size > SEND_BUF_SIZE)
return KM_ERROR_MEMORY_ALLOCATION_FAILED;
uint8_t send_buf[SEND_BUF_SIZE];
Eraser send_buf_eraser(send_buf, SEND_BUF_SIZE);
req.Serialize(send_buf, send_buf + req_size);
// Send it
uint8_t recv_buf[RECV_BUF_SIZE];
Eraser recv_buf_eraser(recv_buf, RECV_BUF_SIZE);
uint32_t rsp_size = RECV_BUF_SIZE;
printf("Sending %d byte request\n", (int)req.SerializedSize());
int rc = trusty_keymaster_call(command, send_buf, req_size, recv_buf, &rsp_size);
if (rc < 0) {
ALOGE("tipc error: %d\n", rc);
// TODO(swillden): Distinguish permanent from transient errors and set error_ appropriately.
return translate_error(rc);
} else {
ALOGV("Received %d byte response\n", rsp_size);
}
const keymaster_message* msg = (keymaster_message *) recv_buf;
const uint8_t *p = msg->payload;
if (!rsp->Deserialize(&p, p + rsp_size)) {
ALOGE("Error deserializing response of size %d\n", (int)rsp_size);
return KM_ERROR_UNKNOWN_ERROR;
} else if (rsp->error != KM_ERROR_OK) {
ALOGE("Response of size %d contained error code %d\n", (int)rsp_size, (int)rsp->error);
return rsp->error;
}
return rsp->error;
}
keymaster_error_t TrustyKeymasterDevice::StoreSigningParams(const void* signing_params,
const uint8_t* key_blob,
size_t key_blob_length,
AuthorizationSet* auth_set) {
uint8_t* pub_key_data;
size_t pub_key_data_length;
int err = get_keypair_public(&device_, key_blob, key_blob_length, &pub_key_data,
&pub_key_data_length);
if (err < 0) {
ALOGE("Error %d extracting public key to determine algorithm", err);
return KM_ERROR_INVALID_KEY_BLOB;
}
UniquePtr<uint8_t, Malloc_Delete> pub_key(pub_key_data);
const uint8_t* p = pub_key_data;
UniquePtr<EVP_PKEY, EVP_PKEY_Delete> pkey(
d2i_PUBKEY(nullptr /* allocate new struct */, &p, pub_key_data_length));
switch (EVP_PKEY_type(pkey->type)) {
case EVP_PKEY_RSA: {
const keymaster_rsa_sign_params_t* rsa_params =
reinterpret_cast<const keymaster_rsa_sign_params_t*>(signing_params);
if (rsa_params->digest_type != DIGEST_NONE)
return KM_ERROR_UNSUPPORTED_DIGEST;
if (rsa_params->padding_type != PADDING_NONE)
return KM_ERROR_UNSUPPORTED_PADDING_MODE;
if (!auth_set->push_back(TAG_DIGEST, KM_DIGEST_NONE) ||
!auth_set->push_back(TAG_PADDING, KM_PAD_NONE))
return KM_ERROR_MEMORY_ALLOCATION_FAILED;
} break;
case EVP_PKEY_EC: {
const keymaster_ec_sign_params_t* ecdsa_params =
reinterpret_cast<const keymaster_ec_sign_params_t*>(signing_params);
if (ecdsa_params->digest_type != DIGEST_NONE)
return KM_ERROR_UNSUPPORTED_DIGEST;
if (!auth_set->push_back(TAG_DIGEST, KM_DIGEST_NONE))
return KM_ERROR_MEMORY_ALLOCATION_FAILED;
} break;
default:
return KM_ERROR_UNSUPPORTED_ALGORITHM;
}
return KM_ERROR_OK;
}
void TrustyKeymasterDevice::StoreNewKeyParams(AuthorizationSet* auth_set) {
auth_set->push_back(TAG_PURPOSE, KM_PURPOSE_SIGN);
auth_set->push_back(TAG_PURPOSE, KM_PURPOSE_VERIFY);
auth_set->push_back(TAG_ALL_USERS);
auth_set->push_back(TAG_NO_AUTH_REQUIRED);
uint64_t now = java_time(time(NULL));
auth_set->push_back(TAG_CREATION_DATETIME, now);
auth_set->push_back(TAG_ORIGINATION_EXPIRE_DATETIME, now + HUNDRED_YEARS);
if (message_version_ == 0) {
auth_set->push_back(TAG_DIGEST_OLD, KM_DIGEST_NONE);
auth_set->push_back(TAG_PADDING_OLD, KM_PAD_NONE);
} else {
auth_set->push_back(TAG_DIGEST, KM_DIGEST_NONE);
auth_set->push_back(TAG_PADDING, KM_PAD_NONE);
}
}
} // namespace keymaster