platform_system_security/keystore/keystore_utils.cpp
Pavel Grafov cef39477f9 NIAP: Log key integrity failure to audit log.
Logs key integrity violation in two cases:
1. software-detected corruption of key blob.
2. keymaster operation returning INVALID_KEY_BLOB

Changed AES_gcm_decrypt to return VALUE_CORRUPTED on decryption errors
to be consistent with digest check for older version blob.

Bug: 70886042
Test: manual, by patching some bytes in the blob.
Test: cts-tradefed run cts -m CtsKeystoreTestCases
Change-Id: Ic8f6b7a2a49aee01253b429644af409e568d7deb
2018-02-15 18:20:28 +00:00

139 lines
4.3 KiB
C++

/*
* Copyright (C) 2016 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 "keystore"
#include "keystore_utils.h"
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <cutils/log.h>
#include <private/android_filesystem_config.h>
#include <private/android_logger.h>
#include <log/log_event_list.h>
#include <keystore/keymaster_types.h>
#include <keystore/keystore_client.h>
#include "blob.h"
size_t readFully(int fd, uint8_t* data, size_t size) {
size_t remaining = size;
while (remaining > 0) {
ssize_t n = TEMP_FAILURE_RETRY(read(fd, data, remaining));
if (n <= 0) {
return size - remaining;
}
data += n;
remaining -= n;
}
return size;
}
size_t writeFully(int fd, uint8_t* data, size_t size) {
size_t remaining = size;
while (remaining > 0) {
ssize_t n = TEMP_FAILURE_RETRY(write(fd, data, remaining));
if (n < 0) {
ALOGW("write failed: %s", strerror(errno));
return size - remaining;
}
data += n;
remaining -= n;
}
if (TEMP_FAILURE_RETRY(fsync(fd)) == -1) {
ALOGW("fsync failed: %s", strerror(errno));
return -1;
}
return size;
}
void add_legacy_key_authorizations(int keyType, keystore::AuthorizationSet* params) {
using namespace keystore;
params->push_back(TAG_PURPOSE, KeyPurpose::SIGN);
params->push_back(TAG_PURPOSE, KeyPurpose::VERIFY);
params->push_back(TAG_PURPOSE, KeyPurpose::ENCRYPT);
params->push_back(TAG_PURPOSE, KeyPurpose::DECRYPT);
params->push_back(TAG_PADDING, PaddingMode::NONE);
if (keyType == EVP_PKEY_RSA) {
params->push_back(TAG_PADDING, PaddingMode::RSA_PKCS1_1_5_SIGN);
params->push_back(TAG_PADDING, PaddingMode::RSA_PKCS1_1_5_ENCRYPT);
params->push_back(TAG_PADDING, PaddingMode::RSA_PSS);
params->push_back(TAG_PADDING, PaddingMode::RSA_OAEP);
}
params->push_back(TAG_DIGEST, Digest::NONE);
params->push_back(TAG_DIGEST, Digest::MD5);
params->push_back(TAG_DIGEST, Digest::SHA1);
params->push_back(TAG_DIGEST, Digest::SHA_2_224);
params->push_back(TAG_DIGEST, Digest::SHA_2_256);
params->push_back(TAG_DIGEST, Digest::SHA_2_384);
params->push_back(TAG_DIGEST, Digest::SHA_2_512);
params->push_back(TAG_NO_AUTH_REQUIRED);
params->push_back(TAG_ORIGINATION_EXPIRE_DATETIME, LLONG_MAX);
params->push_back(TAG_USAGE_EXPIRE_DATETIME, LLONG_MAX);
params->push_back(TAG_ACTIVE_DATETIME, 0);
}
uid_t get_app_id(uid_t uid) {
return uid % AID_USER;
}
uid_t get_user_id(uid_t uid) {
return uid / AID_USER;
}
void log_key_integrity_violation(const char* name, uid_t uid) {
if (!__android_log_security()) return;
android_log_event_list(SEC_TAG_KEY_INTEGRITY_VIOLATION)
<< name << int32_t(uid) << LOG_ID_SECURITY;
}
namespace keystore {
hidl_vec<uint8_t> blob2hidlVec(const Blob& blob) {
hidl_vec<uint8_t> result;
result.setToExternal(const_cast<uint8_t*>(blob.getValue()), blob.getLength());
return result;
}
SecurityLevel flagsToSecurityLevel(int32_t flags) {
switch (flags & (KEYSTORE_FLAG_FALLBACK | KEYSTORE_FLAG_STRONGBOX)) {
case KEYSTORE_FLAG_FALLBACK:
// treating Strongbox flag as "don't care" if Fallback is set
case (KEYSTORE_FLAG_FALLBACK | KEYSTORE_FLAG_STRONGBOX):
return SecurityLevel::SOFTWARE;
case KEYSTORE_FLAG_STRONGBOX:
return SecurityLevel::STRONGBOX;
default:
return SecurityLevel::TRUSTED_ENVIRONMENT;
}
}
uint32_t securityLevelToFlags(SecurityLevel secLevel) {
switch (secLevel) {
case SecurityLevel::SOFTWARE:
return KEYSTORE_FLAG_FALLBACK;
case SecurityLevel::STRONGBOX:
return KEYSTORE_FLAG_STRONGBOX;
default:
return 0;
}
}
} // namespace keystore