blob: bcfa75729ab39df789c8930b6b1320ae13182339 [file] [log] [blame]
/*
* Copyright (C) 2018 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 <regex.h>
#include <android-base/logging.h>
#include <android-base/properties.h>
#include <hardware/hw_auth_token.h>
#include <keymasterV4_0/keymaster_utils.h>
namespace android::hardware {
inline static bool operator<(const hidl_vec<uint8_t>& a, const hidl_vec<uint8_t>& b) {
auto result = memcmp(a.data(), b.data(), std::min(a.size(), b.size()));
if (!result) return a.size() < b.size();
return result < 0;
}
template <size_t SIZE>
inline static bool operator<(const hidl_array<uint8_t, SIZE>& a,
const hidl_array<uint8_t, SIZE>& b) {
return memcmp(a.data(), b.data(), SIZE) == -1;
}
namespace keymaster::V4_0 {
bool operator<(const HmacSharingParameters& a, const HmacSharingParameters& b) {
return std::tie(a.seed, a.nonce) < std::tie(b.seed, b.nonce);
}
namespace support {
template <typename T, typename InIter>
inline static InIter copy_bytes_from_iterator(T* value, InIter src) {
uint8_t* value_ptr = reinterpret_cast<uint8_t*>(value);
std::copy(src, src + sizeof(T), value_ptr);
return src + sizeof(T);
}
template <typename T, typename OutIter>
inline static OutIter copy_bytes_to_iterator(const T& value, OutIter dest) {
const uint8_t* value_ptr = reinterpret_cast<const uint8_t*>(&value);
return std::copy(value_ptr, value_ptr + sizeof(value), dest);
}
constexpr size_t kHmacSize = 32;
hidl_vec<uint8_t> authToken2HidlVec(const HardwareAuthToken& token) {
static_assert(1 /* version size */ + sizeof(token.challenge) + sizeof(token.userId) +
sizeof(token.authenticatorId) + sizeof(token.authenticatorType) +
sizeof(token.timestamp) + kHmacSize ==
sizeof(hw_auth_token_t),
"HardwareAuthToken content size does not match hw_auth_token_t size");
hidl_vec<uint8_t> result;
result.resize(sizeof(hw_auth_token_t));
auto pos = result.begin();
*pos++ = 0; // Version byte
pos = copy_bytes_to_iterator(token.challenge, pos);
pos = copy_bytes_to_iterator(token.userId, pos);
pos = copy_bytes_to_iterator(token.authenticatorId, pos);
auto auth_type = htonl(static_cast<uint32_t>(token.authenticatorType));
pos = copy_bytes_to_iterator(auth_type, pos);
auto timestamp = htonq(token.timestamp);
pos = copy_bytes_to_iterator(timestamp, pos);
if (token.mac.size() != kHmacSize) {
std::fill(pos, pos + kHmacSize, 0);
} else {
std::copy(token.mac.begin(), token.mac.end(), pos);
}
return result;
}
HardwareAuthToken hidlVec2AuthToken(const hidl_vec<uint8_t>& buffer) {
HardwareAuthToken token;
static_assert(1 /* version size */ + sizeof(token.challenge) + sizeof(token.userId) +
sizeof(token.authenticatorId) + sizeof(token.authenticatorType) +
sizeof(token.timestamp) + kHmacSize ==
sizeof(hw_auth_token_t),
"HardwareAuthToken content size does not match hw_auth_token_t size");
if (buffer.size() != sizeof(hw_auth_token_t)) return {};
auto pos = buffer.begin();
++pos; // skip first byte
pos = copy_bytes_from_iterator(&token.challenge, pos);
pos = copy_bytes_from_iterator(&token.userId, pos);
pos = copy_bytes_from_iterator(&token.authenticatorId, pos);
pos = copy_bytes_from_iterator(&token.authenticatorType, pos);
token.authenticatorType = static_cast<HardwareAuthenticatorType>(
ntohl(static_cast<uint32_t>(token.authenticatorType)));
pos = copy_bytes_from_iterator(&token.timestamp, pos);
token.timestamp = ntohq(token.timestamp);
token.mac.resize(kHmacSize);
std::copy(pos, pos + kHmacSize, token.mac.data());
return token;
}
void appendUint64(std::vector<uint8_t>& vec, uint64_t value) {
for (size_t n = 0; n < sizeof(uint64_t); n++) {
uint8_t byte = (value >> (n * 8)) & 0xff;
vec.push_back(byte);
}
}
uint64_t extractUint64(const std::vector<uint8_t>& data, size_t offset) {
uint64_t value = 0;
for (size_t n = 0; n < sizeof(uint64_t); n++) {
uint64_t tmp = data[offset + n];
value |= (tmp << (n * 8));
}
return value;
}
void appendUint32(std::vector<uint8_t>& vec, uint32_t value) {
for (size_t n = 0; n < sizeof(uint32_t); n++) {
uint8_t byte = (value >> (n * 8)) & 0xff;
vec.push_back(byte);
}
}
uint32_t extractUint32(const std::vector<uint8_t>& data, size_t offset) {
uint32_t value = 0;
for (size_t n = 0; n < sizeof(uint32_t); n++) {
uint32_t tmp = data[offset + n];
value |= (tmp << (n * 8));
}
return value;
}
std::optional<std::vector<uint8_t>> serializeVerificationToken(const VerificationToken& token) {
if (token.parametersVerified.size() > 0) {
LOG(ERROR) << "Serializing verification tokens with parametersVerified is not supported";
return {};
}
if (!(token.mac.size() == 0 || token.mac.size() == 32)) {
LOG(ERROR) << "Unexpected MAC size " << token.mac.size() << ", expected 0 or 32";
return {};
}
std::vector<uint8_t> serializedToken;
appendUint64(serializedToken, token.challenge);
appendUint64(serializedToken, token.timestamp);
appendUint32(serializedToken, uint32_t(token.securityLevel));
appendUint32(serializedToken, token.mac.size());
serializedToken.insert(serializedToken.end(), token.mac.begin(), token.mac.end());
return serializedToken;
}
std::optional<VerificationToken> deserializeVerificationToken(
const std::vector<uint8_t>& serializedToken) {
if (serializedToken.size() < 24) {
LOG(ERROR) << "Unexpected serialized VerificationToken size " << serializedToken.size()
<< ", expected at least 24 bytes";
return {};
}
VerificationToken token;
token.challenge = extractUint64(serializedToken, 0);
token.timestamp = extractUint64(serializedToken, 8);
token.securityLevel = SecurityLevel(extractUint32(serializedToken, 16));
size_t macSize = extractUint32(serializedToken, 20);
size_t expectedSerializedSize = 24 + macSize;
if (serializedToken.size() != expectedSerializedSize) {
LOG(ERROR) << "Unexpected serialized VerificationToken size " << serializedToken.size()
<< ", expected " << expectedSerializedSize;
return {};
}
if (macSize > 0) {
token.mac = std::vector<uint8_t>(serializedToken.begin() + 24, serializedToken.end());
}
return token;
}
namespace {
constexpr char kPlatformVersionProp[] = "ro.build.version.release";
constexpr char kPlatformVersionRegex[] = "^([0-9]{1,2})(\\.([0-9]{1,2}))?(\\.([0-9]{1,2}))?";
constexpr size_t kMajorVersionMatch = 1;
constexpr size_t kMinorVersionMatch = 3;
constexpr size_t kSubminorVersionMatch = 5;
constexpr size_t kPlatformVersionMatchCount = kSubminorVersionMatch + 1;
constexpr char kPlatformPatchlevelProp[] = "ro.build.version.security_patch";
constexpr char kPlatformPatchlevelRegex[] = "^([0-9]{4})-([0-9]{2})-[0-9]{2}$";
constexpr size_t kYearMatch = 1;
constexpr size_t kMonthMatch = 2;
constexpr size_t kPlatformPatchlevelMatchCount = kMonthMatch + 1;
uint32_t match_to_uint32(const char* expression, const regmatch_t& match) {
if (match.rm_so == -1) return 0;
size_t len = match.rm_eo - match.rm_so;
std::string s(expression + match.rm_so, len);
return std::stoul(s);
}
std::string wait_and_get_property(const char* prop) {
std::string prop_value;
while (!android::base::WaitForPropertyCreation(prop))
;
prop_value = android::base::GetProperty(prop, "" /* default */);
return prop_value;
}
} // anonymous namespace
uint32_t getOsVersion(const char* version_str) {
regex_t regex;
if (regcomp(&regex, kPlatformVersionRegex, REG_EXTENDED)) {
return 0;
}
regmatch_t matches[kPlatformVersionMatchCount];
int not_match =
regexec(&regex, version_str, kPlatformVersionMatchCount, matches, 0 /* flags */);
regfree(&regex);
if (not_match) {
return 0;
}
uint32_t major = match_to_uint32(version_str, matches[kMajorVersionMatch]);
uint32_t minor = match_to_uint32(version_str, matches[kMinorVersionMatch]);
uint32_t subminor = match_to_uint32(version_str, matches[kSubminorVersionMatch]);
return (major * 100 + minor) * 100 + subminor;
}
uint32_t getOsVersion() {
std::string version = wait_and_get_property(kPlatformVersionProp);
return getOsVersion(version.c_str());
}
uint32_t getOsPatchlevel(const char* patchlevel_str) {
regex_t regex;
if (regcomp(&regex, kPlatformPatchlevelRegex, REG_EXTENDED) != 0) {
return 0;
}
regmatch_t matches[kPlatformPatchlevelMatchCount];
int not_match =
regexec(&regex, patchlevel_str, kPlatformPatchlevelMatchCount, matches, 0 /* flags */);
regfree(&regex);
if (not_match) {
return 0;
}
uint32_t year = match_to_uint32(patchlevel_str, matches[kYearMatch]);
uint32_t month = match_to_uint32(patchlevel_str, matches[kMonthMatch]);
if (month < 1 || month > 12) {
return 0;
}
return year * 100 + month;
}
uint32_t getOsPatchlevel() {
std::string patchlevel = wait_and_get_property(kPlatformPatchlevelProp);
return getOsPatchlevel(patchlevel.c_str());
}
} // namespace support
} // namespace keymaster::V4_0
} // namespace android::hardware