/**
* Update a command with the content and tree hash headers, as needed.
*
* @param PreparedEvent $event Event emitted.
*
* @throws \RuntimeException if the body is not seekable.
*/
public function onPrepared(PreparedEvent $event)
{
$command = $event->getCommand();
$name = $command->getName();
// Determine if there is a need to calculate any hashes.
$needsHashes = ($name === 'UploadArchive' || $name === 'UploadPart') && (!$command['checksum'] || !$command['ContentSHA256']);
if ($needsHashes) {
$body = $event->getRequest()->getBody();
if (!$body->isSeekable()) {
throw new CouldNotCreateChecksumException('sha256');
}
// Add a tree hash if not provided.
if (!$command['checksum']) {
$body = new HashingStream($body, new TreeHash(), function ($result) use($command, $event) {
$event->getRequest()->setHeader('x-amz-sha256-tree-hash', bin2hex($result));
});
}
// Add a linear content hash if not provided.
if (!$command['ContentSHA256']) {
$body = new HashingStream($body, new PhpHash('sha256'), function ($result) use($command) {
$command['ContentSHA256'] = bin2hex($result);
});
}
// Read the stream in order to calculate the hashes.
while (!$body->eof()) {
$body->read(1048576);
}
$body->seek(0);
}
// Set the content hash header if there is a value to set.
if ($hash = $command['ContentSHA256']) {
$event->getRequest()->addHeader('x-amz-content-sha256', $hash);
}
}
/**
* @param StreamInterface $stream Stream that is validated.
* @param HashInterface $hash Hash used to calculate the hash.
* @param string $expected The expected hash result.
* @param callable $onMismatch Optional function to invoke when there
* is a mismatch between the calculated hash and the expected hash.
* The callback is called with the resulting hash and the expected hash.
* This callback can be used to throw specific exceptions.
*/
public function __construct(StreamInterface $stream, HashInterface $hash, $expected, $onMismatch = null)
{
$this->mismatchCallback = $onMismatch;
$this->expected = $expected;
$that = $this;
parent::__construct($stream, $hash, function ($result) use($that) {
if ($that->expected !== $result) {
$that->mismatch($result);
}
});
}