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#include "disk_cache.h"
#include <library/cpp/tvmauth/client/logger.h>
#include <contrib/libs/openssl/include/openssl/evp.h>
#include <contrib/libs/openssl/include/openssl/hmac.h>
#include <contrib/libs/openssl/include/openssl/sha.h>
#include <util/folder/path.h>
#include <util/stream/file.h>
#include <util/stream/str.h>
#include <util/system/fs.h>
#include <util/system/sysstat.h>
#include <util/system/tempfile.h>
#include <exception>
namespace NTvmAuth {
static const size_t HASH_SIZE = 32;
static const size_t TIMESTAMP_SIZE = sizeof(time_t);
TDiskReader::TDiskReader(const TString& filename, ILogger* logger)
: Filename_(filename)
, Logger_(logger)
{
}
bool TDiskReader::Read() {
TStringStream s;
try {
if (!NFs::Exists(Filename_)) {
if (Logger_) {
s << "File '" << Filename_ << "' does not exist";
Logger_->Debug(s.Str());
}
return false;
}
TFile file(Filename_, OpenExisting | RdOnly | Seq);
file.Flock(LOCK_SH | LOCK_NB);
TFileInput input(file);
return ParseData(input.ReadAll());
} catch (const std::exception& e) {
if (Logger_) {
s << "Failed to read '" << Filename_ << "': " << e.what();
Logger_->Error(s.Str());
}
}
return false;
}
bool TDiskReader::ParseData(TStringBuf buf) {
TStringStream s;
if (buf.size() <= HASH_SIZE + TIMESTAMP_SIZE) {
if (Logger_) {
s << "File '" << Filename_ << "' is too small";
Logger_->Warning(s.Str());
}
return false;
}
TStringBuf hash = buf.SubStr(0, HASH_SIZE);
if (hash != GetHash(buf.Skip(HASH_SIZE))) {
if (Logger_) {
s << "Content of '" << Filename_ << "' was incorrectly changed";
Logger_->Warning(s.Str());
}
return false;
}
Time_ = TInstant::Seconds(GetTimestamp(buf.substr(0, TIMESTAMP_SIZE)));
Data_ = buf.Skip(TIMESTAMP_SIZE);
if (Logger_) {
s << "File '" << Filename_ << "' was successfully read";
Logger_->Info(s.Str());
}
return true;
}
TString TDiskReader::GetHash(TStringBuf data) {
TString value(EVP_MAX_MD_SIZE, 0);
unsigned macLen = 0;
if (!::HMAC(EVP_sha256(),
"",
0,
(unsigned char*)data.data(),
data.size(),
(unsigned char*)value.data(),
&macLen)) {
return {};
}
if (macLen != EVP_MAX_MD_SIZE) {
value.resize(macLen);
}
return value;
}
time_t TDiskReader::GetTimestamp(TStringBuf data) {
time_t time = 0;
for (int idx = TIMESTAMP_SIZE - 1; idx >= 0; --idx) {
time <<= 8;
time |= static_cast<unsigned char>(data.at(idx));
}
return time;
}
TDiskWriter::TDiskWriter(const TString& filename, ILogger* logger)
: Filename_(filename)
, Logger_(logger)
{
}
bool TDiskWriter::Write(TStringBuf data, TInstant now) {
TStringStream s;
try {
{
if (NFs::Exists(Filename_)) {
Chmod(Filename_.c_str(),
S_IRUSR | S_IWUSR); // 600
}
TFile file(Filename_, CreateAlways | WrOnly | Seq | AWUser | ARUser);
file.Flock(LOCK_EX | LOCK_NB);
TFileOutput output(file);
output << PrepareData(now, data);
}
if (Logger_) {
s << "File '" << Filename_ << "' was successfully written";
Logger_->Info(s.Str());
}
return true;
} catch (const std::exception& e) {
if (Logger_) {
s << "Failed to write '" << Filename_ << "': " << e.what();
Logger_->Error(s.Str());
}
}
return false;
}
TString TDiskWriter::PrepareData(TInstant time, TStringBuf data) {
TString toHash = WriteTimestamp(time.TimeT()) + data;
return TDiskReader::GetHash(toHash) + toHash;
}
TString TDiskWriter::WriteTimestamp(time_t time) {
TString res(TIMESTAMP_SIZE, 0);
for (size_t idx = 0; idx < TIMESTAMP_SIZE; ++idx) {
res[idx] = time & 0xFF;
time >>= 8;
}
return res;
}
}
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