/*
**
** Copyright 2017, 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 <keymaster/contexts/keymaster1_passthrough_context.h>
#include <keymaster/legacy_support/keymaster_passthrough_key.h>
#include <keymaster/legacy_support/keymaster_passthrough_engine.h>
#include <keymaster/legacy_support/keymaster1_legacy_support.h>
#include <keymaster/legacy_support/keymaster1_engine.h>
#include <keymaster/legacy_support/rsa_keymaster1_key.h>
#include <keymaster/legacy_support/ec_keymaster1_key.h>
#include <keymaster/key_blob_utils/software_keyblobs.h>
#include <keymaster/key_blob_utils/integrity_assured_key_blob.h>
#include <keymaster/key_blob_utils/ocb_utils.h>
#include <keymaster/km_openssl/aes_key.h>
#include <keymaster/km_openssl/hmac_key.h>
#include <keymaster/km_openssl/attestation_utils.h>
#include "soft_attestation_cert.h"
namespace keymaster {
Keymaster1PassthroughContext::Keymaster1PassthroughContext(keymaster1_device_t* dev)
: device_(dev), pt_engine_(KeymasterPassthroughEngine::createInstance(dev)),
km1_engine_(new Keymaster1Engine(dev)) {
}
keymaster_error_t Keymaster1PassthroughContext::SetSystemVersion(uint32_t os_version,
uint32_t os_patchlevel) {
os_version_ = os_version;
os_patchlevel_ = os_patchlevel;
return KM_ERROR_OK;
}
void Keymaster1PassthroughContext::GetSystemVersion(uint32_t* os_version,
uint32_t* os_patchlevel) const {
if (os_version) *os_version = os_version_;
if (os_patchlevel) *os_patchlevel = os_patchlevel_;
}
KeyFactory* Keymaster1PassthroughContext::GetKeyFactory(keymaster_algorithm_t algorithm) const {
auto& result = factories_[algorithm];
if (!result) {
switch(algorithm) {
case KM_ALGORITHM_RSA:
result.reset(new Keymaster1ArbitrationFactory<RsaKeymaster1KeyFactory>(pt_engine_.get(),
KM_ALGORITHM_RSA, device_, this, km1_engine_.get()));
break;
case KM_ALGORITHM_EC:
result.reset(new Keymaster1ArbitrationFactory<EcdsaKeymaster1KeyFactory>(pt_engine_.get(),
KM_ALGORITHM_EC, device_, this, km1_engine_.get()));
break;
case KM_ALGORITHM_AES:
result.reset(new Keymaster1ArbitrationFactory<AesKeyFactory>(pt_engine_.get(),
KM_ALGORITHM_AES, device_, this, this));
break;
case KM_ALGORITHM_HMAC:
result.reset(new Keymaster1ArbitrationFactory<HmacKeyFactory>(pt_engine_.get(),
KM_ALGORITHM_HMAC, device_, this, this));
break;
case KM_ALGORITHM_TRIPLE_DES:
// Not supported by KM1.
return nullptr;
}
}
return result.get();
}
OperationFactory* Keymaster1PassthroughContext::GetOperationFactory(keymaster_algorithm_t algorithm,
keymaster_purpose_t purpose) const {
auto keyfactory = GetKeyFactory(algorithm);
return keyfactory->GetOperationFactory(purpose);
}
keymaster_algorithm_t* Keymaster1PassthroughContext::GetSupportedAlgorithms(
size_t* algorithms_count) const {
if (algorithms_count) *algorithms_count = 0;
return nullptr;
}
keymaster_error_t Keymaster1PassthroughContext::UpgradeKeyBlob(
const KeymasterKeyBlob& key_to_upgrade, const AuthorizationSet& upgrade_params,
KeymasterKeyBlob* upgraded_key) const {
UniquePtr<Key> key;
keymaster_error_t error = ParseKeyBlob(key_to_upgrade, upgrade_params, &key);
if (error != KM_ERROR_OK)
return error;
if (key->hw_enforced().Contains(TAG_PURPOSE) &&
!key->hw_enforced().Contains(TAG_OS_PATCHLEVEL)) {
return KM_ERROR_INVALID_ARGUMENT;
}
return UpgradeSoftKeyBlob(key, os_version_, os_patchlevel_, upgrade_params, upgraded_key);
}
static keymaster_error_t parseKeymaster1HwBlob(const keymaster1_device_t* device,
const KeymasterKeyBlob& blob,
const AuthorizationSet& additional_params,
KeymasterKeyBlob* key_material,
AuthorizationSet* hw_enforced,
AuthorizationSet* sw_enforced) {
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;
// Get key characteristics, which incidentally verifies that the HW recognizes the key.
keymaster_key_characteristics_t* characteristics;
keymaster_error_t error = device->get_key_characteristics(device, &blob, client_id_ptr,
app_data_ptr, &characteristics);
if (error != KM_ERROR_OK)
return error;
UniquePtr<keymaster_key_characteristics_t, Characteristics_Delete> characteristics_deleter(
characteristics);
hw_enforced->Reinitialize(characteristics->hw_enforced);
sw_enforced->Reinitialize(characteristics->sw_enforced);
*key_material = blob;
return KM_ERROR_OK;
}
keymaster_error_t Keymaster1PassthroughContext::ParseKeyBlob(const KeymasterKeyBlob& blob,
const AuthorizationSet& additional_params, UniquePtr<Key>* key) const {
AuthorizationSet hw_enforced;
AuthorizationSet sw_enforced;
KeymasterKeyBlob key_material;
AuthorizationSet hidden;
keymaster_error_t error = BuildHiddenAuthorizations(additional_params, &hidden,
softwareRootOfTrust);
if (error != KM_ERROR_OK)
return error;
// Assume it's an integrity-assured blob (new software-only blob
error = DeserializeIntegrityAssuredBlob(blob, hidden, &key_material, &hw_enforced, &sw_enforced);
if (error != KM_ERROR_INVALID_KEY_BLOB && error != KM_ERROR_OK)
return error;
if (error == KM_ERROR_INVALID_KEY_BLOB) {
error = parseKeymaster1HwBlob(km1_engine_->device(), blob, additional_params,
&key_material, &hw_enforced, &sw_enforced);
if (error != KM_ERROR_OK) return error;
}
// GetKeyFactory
keymaster_algorithm_t algorithm;
if (!hw_enforced.GetTagValue(TAG_ALGORITHM, &algorithm) &&
!sw_enforced.GetTagValue(TAG_ALGORITHM, &algorithm)) {
return KM_ERROR_INVALID_ARGUMENT;
}
auto factory = GetKeyFactory(algorithm);
return factory->LoadKey(move(key_material), additional_params, move(hw_enforced),
move(sw_enforced), key);
}
keymaster_error_t Keymaster1PassthroughContext::DeleteKey(const KeymasterKeyBlob& blob) const {
// HACK. Due to a bug with Qualcomm's Keymaster implementation, which causes the device to
// reboot if we pass it a key blob it doesn't understand, we need to check for software
// keys. If it looks like a software key there's nothing to do so we just return.
// Can be removed once b/33385206 is fixed
KeymasterKeyBlob key_material;
AuthorizationSet hw_enforced, sw_enforced;
keymaster_error_t error = DeserializeIntegrityAssuredBlob_NoHmacCheck(
blob, &key_material, &hw_enforced, &sw_enforced);
if (error == KM_ERROR_OK) {
return KM_ERROR_OK;
}
error = km1_engine_->DeleteKey(blob);
if (error == KM_ERROR_INVALID_KEY_BLOB) {
// Some implementations diagnose invalid keys.
// However, all care we about is that the key blob, as supplied, is not usable after the
// call.
return KM_ERROR_OK;
}
return error;
}
keymaster_error_t Keymaster1PassthroughContext::DeleteAllKeys() const {
return km1_engine_->DeleteAllKeys();
}
keymaster_error_t Keymaster1PassthroughContext::AddRngEntropy(const uint8_t* buf,
size_t length) const {
return device_->add_rng_entropy(device_, buf, length);
}
KeymasterEnforcement* Keymaster1PassthroughContext::enforcement_policy() {
return nullptr;
}
keymaster_error_t Keymaster1PassthroughContext::CreateKeyBlob(const AuthorizationSet& key_description,
const keymaster_key_origin_t origin,
const KeymasterKeyBlob& key_material,
KeymasterKeyBlob* blob,
AuthorizationSet* hw_enforced,
AuthorizationSet* sw_enforced) const {
keymaster_error_t error = SetKeyBlobAuthorizations(key_description, origin, os_version_,
os_patchlevel_, hw_enforced, sw_enforced);
if (error != KM_ERROR_OK)
return error;
AuthorizationSet hidden;
error = BuildHiddenAuthorizations(key_description, &hidden, softwareRootOfTrust);
if (error != KM_ERROR_OK)
return error;
return SerializeIntegrityAssuredBlob(key_material, hidden, *hw_enforced, *sw_enforced, blob);
}
keymaster_error_t Keymaster1PassthroughContext::GenerateAttestation(const Key& key,
const AuthorizationSet& attest_params, CertChainPtr* cert_chain) const {
keymaster_error_t error = KM_ERROR_OK;
keymaster_algorithm_t key_algorithm;
if (!key.authorizations().GetTagValue(TAG_ALGORITHM, &key_algorithm)) {
return KM_ERROR_UNKNOWN_ERROR;
}
if ((key_algorithm != KM_ALGORITHM_RSA && key_algorithm != KM_ALGORITHM_EC))
return KM_ERROR_INCOMPATIBLE_ALGORITHM;
// We have established that the given key has the correct algorithm, and because this is the
// SoftKeymasterContext we can assume that the Key is an AsymmetricKey. So we can downcast.
const AsymmetricKey& asymmetric_key = static_cast<const AsymmetricKey&>(key);
auto attestation_chain = getAttestationChain(key_algorithm, &error);
if (error != KM_ERROR_OK) return error;
auto attestation_key = getAttestationKey(key_algorithm, &error);
if (error != KM_ERROR_OK) return error;
return generate_attestation(asymmetric_key, attest_params,
*attestation_chain, *attestation_key, *this, cert_chain);
}
keymaster_error_t Keymaster1PassthroughContext::UnwrapKey(
const KeymasterKeyBlob&, const KeymasterKeyBlob&, const AuthorizationSet&,
const KeymasterKeyBlob&, AuthorizationSet*, keymaster_key_format_t*, KeymasterKeyBlob*) const {
return KM_ERROR_UNIMPLEMENTED;
}
} // namespace keymaster