1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
<?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;
}
}
|
