Viewing file:  ValidateResponseChecksumParser.php (5.09 KB) -rw-r--r--
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<?php
namespace Aws\S3;
use Aws\Api\Parser\AbstractParser;
use Aws\Api\Service;
use Aws\Api\StructureShape;
use Aws\CommandInterface;
use Aws\S3\Exception\S3Exception;
use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\StreamInterface;
/**
* @internal Decorates a parser for the S3 service to validate the response checksum.
*/
class ValidateResponseChecksumParser extends AbstractParser
{
use CalculatesChecksumTrait;
/**
* @param callable $parser Parser to wrap.
*/
public function __construct(callable $parser, Service $api)
{
$this->api = $api;
$this->parser = $parser;
}
public function __invoke(
CommandInterface $command,
ResponseInterface $response
) {
$fn = $this->parser;
$result = $fn($command, $response);
//Skip this middleware if the operation doesn't have an httpChecksum
$op = $this->api->getOperation($command->getName());
$checksumInfo = isset($op['httpChecksum'])
? $op['httpChecksum']
: [];
if (empty($checksumInfo)) {
return $result;
}
//Skip this middleware if the operation doesn't send back a checksum, or the user doesn't opt in
$checksumModeEnabledMember = isset($checksumInfo['requestValidationModeMember'])
? $checksumInfo['requestValidationModeMember']
: "";
$checksumModeEnabled = isset($command[$checksumModeEnabledMember])
? $command[$checksumModeEnabledMember]
: "";
$responseAlgorithms = isset($checksumInfo['responseAlgorithms'])
? $checksumInfo['responseAlgorithms']
: [];
if (empty($responseAlgorithms)
|| strtolower($checksumModeEnabled) !== "enabled"
) {
return $result;
}
if (extension_loaded('awscrt')) {
$checksumPriority = ['CRC32C', 'CRC32', 'SHA1', 'SHA256'];
} else {
$checksumPriority = ['CRC32', 'SHA1', 'SHA256'];
}
$checksumsToCheck = array_intersect($responseAlgorithms, $checksumPriority);
$checksumValidationInfo = $this->validateChecksum($checksumsToCheck, $response);
if ($checksumValidationInfo['status'] == "SUCCEEDED") {
$result['ChecksumValidated'] = $checksumValidationInfo['checksum'];
} else if ($checksumValidationInfo['status'] == "FAILED"){
//Ignore failed validations on GetObject if it's a multipart get which returned a full multipart object
if ($command->getName() == "GetObject"
&& !empty($checksumValidationInfo['checksumHeaderValue'])
) {
$headerValue = $checksumValidationInfo['checksumHeaderValue'];
$lastDashPos = strrpos($headerValue, '-');
$endOfChecksum = substr($headerValue, $lastDashPos + 1);
if (is_numeric($endOfChecksum)
&& intval($endOfChecksum) > 1
&& intval($endOfChecksum) < 10000) {
return $result;
}
}
throw new S3Exception(
"Calculated response checksum did not match the expected value",
$command
);
}
return $result;
}
public function parseMemberFromStream(
StreamInterface $stream,
StructureShape $member,
$response
) {
return $this->parser->parseMemberFromStream($stream, $member, $response);
}
/**
* @param $checksumPriority
* @param ResponseInterface $response
*/
public function validateChecksum($checksumPriority, ResponseInterface $response)
{
$checksumToValidate = $this->chooseChecksumHeaderToValidate(
$checksumPriority,
$response
);
$validationStatus = "SKIPPED";
$checksumHeaderValue = null;
if (!empty($checksumToValidate)) {
$checksumHeaderValue = $response->getHeader(
'x-amz-checksum-' . $checksumToValidate
);
if (isset($checksumHeaderValue)) {
$checksumHeaderValue = $checksumHeaderValue[0];
$calculatedChecksumValue = $this->getEncodedValue(
$checksumToValidate,
$response->getBody()
);
$validationStatus = $checksumHeaderValue == $calculatedChecksumValue
? "SUCCEEDED"
: "FAILED";
}
}
return [
"status" => $validationStatus,
"checksum" => $checksumToValidate,
"checksumHeaderValue" => $checksumHeaderValue,
];
}
/**
* @param $checksumPriority
* @param ResponseInterface $response
*/
public function chooseChecksumHeaderToValidate(
$checksumPriority,
ResponseInterface $response
) {
foreach ($checksumPriority as $checksum) {
$checksumHeader = 'x-amz-checksum-' . $checksum;
if ($response->hasHeader($checksumHeader)) {
return $checksum;
}
}
return null;
}
}
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