<?php
declare(strict_types=1);
namespace ParagonIE\Chronicle\Process;
use ParagonIE\Chronicle\Chronicle;
use ParagonIE\Chronicle\Exception\{
ChainAppendException,
FilesystemException
};
use ParagonIE\ConstantTime\Base64UrlSafe;
/**
* Class Attest
*
* This process publishes the latest hash of each replicated Chronicle
* onto the local instance, to create an immutable record of the replicated
* Chronicles and provide greater resilience against malicious tampering.
*
* @package ParagonIE\Chronicle\Process
*/
class Attest
{
/** @var array<string, string> */
protected $settings;
/**
* Attest constructor.
* @param array<string, string> $settings
*/
public function __construct(array $settings = [])
{
if (empty($settings)) {
$settings = Chronicle::getSettings();
}
$this->settings = $settings;
}
/**
* Do we need to run the attestation process?
*
* @return bool
*
* @throws FilesystemException
*/
public function isScheduled(): bool
{
/** @var string $query */
$query = 'SELECT count(id) FROM ' . Chronicle::getTableName('replication_sources');
if (!Chronicle::getDatabase()->exists($query)) {
return false;
}
if (!isset($this->settings['scheduled-attestation'])) {
return false;
}
if (!\file_exists(CHRONICLE_APP_ROOT . '/local/replication-last-run')) {
return true;
}
$lastRun = \file_get_contents(CHRONICLE_APP_ROOT . '/local/replication-last-run');
if (!\is_string($lastRun)) {
throw new FilesystemException('Could not read replication last run file');
}
$now = new \DateTimeImmutable('NOW');
$runTime = new \DateTimeImmutable($lastRun);
// Return true only if the next scheduled run has come to pass.
$interval = \DateInterval::createFromDateString($this->settings['scheduled-attestation']);
$nextRunTime = $runTime->add($interval);
return $nextRunTime < $now;
}
/**
* @return void
*
* @throws ChainAppendException
* @throws FilesystemException
* @throws \SodiumException
*/
public function run()
{
$now = (new \DateTime('NOW'))->format(\DateTime::ATOM);
/** @var int|bool $lock */
$lock = \file_put_contents(
CHRONICLE_APP_ROOT . '/local/replication-last-run',
$now
);
if (!\is_int($lock)) {
throw new FilesystemException('Cannot save replication last run file.');
}
$this->attestAll();
}
/**
* @return array
*
* @throws ChainAppendException
* @throws FilesystemException
* @throws \SodiumException
* @throws \TypeError
*/
public function attestAll(): array
{
$hashes = [];
$db = Chronicle::getDatabase();
/** @var array<int, array<string, string>> $rows */
$rows = $db->run('SELECT id, uniqueid FROM ' . Chronicle::getTableName('replication_sources'));
/** @var array<string, string> $row */
foreach ($rows as $row) {
/** @var array<string, string> $latest */
$latest = $db->row(
"SELECT
currhash,
summaryhash
FROM
" . Chronicle::getTableName('replication_chain') . "
WHERE
source = ?
ORDER BY id DESC
LIMIT 1",
$row['id']
);
$latest['source'] = $row['uniqueid'];
$hashes[] = $latest;
}
// Build the message
/** @var string $message */
$message = \json_encode(
[
'version' => Chronicle::VERSION,
'datetime' => (new \DateTime())->format(\DateTime::ATOM),
'replication-hashes' => $hashes
],
JSON_PRETTY_PRINT
);
if (!\is_string($message)) {
throw new \TypeError('Invalid messsage');
}
// Sign the message:
$signature = Base64UrlSafe::encode(
\ParagonIE_Sodium_Compat::crypto_sign_detached(
$message,
Chronicle::getSigningKey()->getString(true)
)
);
// Write the message onto the local Blakechain
return Chronicle::extendBlakechain(
$message,
$signature,
Chronicle::getSigningKey()->getPublicKey()
);
}
}
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