|
1
|
|
|
<?php declare(strict_types=1); |
|
2
|
|
|
|
|
3
|
|
|
namespace ncryptf; |
|
4
|
|
|
|
|
5
|
|
|
use ncryptf\exceptions\InvalidChecksumException; |
|
6
|
|
|
use ncryptf\exceptions\InvalidSignatureException; |
|
7
|
|
|
use InvalidArgumentException; |
|
8
|
|
|
use SodiumException; |
|
9
|
|
|
|
|
10
|
|
|
class Response |
|
11
|
|
|
{ |
|
12
|
|
|
/** |
|
13
|
|
|
* Sodium CryptoBox Keypair |
|
14
|
|
|
* |
|
15
|
|
|
* @var string |
|
16
|
|
|
*/ |
|
17
|
|
|
private $keypair; |
|
18
|
|
|
|
|
19
|
|
|
/** |
|
20
|
|
|
* Constructor |
|
21
|
|
|
* |
|
22
|
|
|
* @param string $secretKey The 32 byte secret key |
|
23
|
|
|
* @param string $publicKey The 32 byte public key |
|
24
|
|
|
* |
|
25
|
|
|
* @throws InvalidArguementException |
|
26
|
|
|
*/ |
|
27
|
|
|
public function __construct(string $secretKey, string $publicKey) |
|
28
|
|
|
{ |
|
29
|
|
|
try { |
|
30
|
|
|
$this->keypair = \sodium_crypto_box_keypair_from_secretkey_and_publickey( |
|
31
|
|
|
$secretKey, |
|
32
|
|
|
$publicKey |
|
33
|
|
|
); |
|
34
|
|
|
} catch (SodiumException $e) { |
|
35
|
|
|
throw new InvalidArgumentException($e->getMessage()); |
|
36
|
|
|
} |
|
37
|
|
|
} |
|
38
|
|
|
|
|
39
|
|
|
/** |
|
40
|
|
|
* Decrypts a payload using the response and an optional nonce |
|
41
|
|
|
* Nonce is not required for v2 type signatures, but is required for v1 signatures |
|
42
|
|
|
* |
|
43
|
|
|
* @param string $response The encrypted HTTP response, as a multi-byte string |
|
44
|
|
|
* @param string $nonce The 32 byte nonce |
|
45
|
|
|
* |
|
46
|
|
|
* @throws InvalidArguementException |
|
47
|
|
|
*/ |
|
48
|
|
|
public function decrypt(string $response, string $nonce = null) : string |
|
49
|
|
|
{ |
|
50
|
|
|
$version = $this->getVersion($response); |
|
51
|
|
|
if ($version === 2) { |
|
52
|
|
|
$nonce = \substr($response, 4, 24); |
|
53
|
|
|
// Determine the payload size sans the 64 byte checksum at the end |
|
54
|
|
|
$payload = \substr($response, 0, \strlen($response) - 64); |
|
55
|
|
|
$checksum = \substr($response, -64); |
|
56
|
|
|
|
|
57
|
|
|
// Verify the checksum to ensure the headers haven't been tampered with |
|
58
|
|
|
if ($checksum !== \sodium_crypto_generichash($payload, $nonce, 64)) { |
|
59
|
|
|
throw new InvalidChecksumException; |
|
60
|
|
|
} |
|
61
|
|
|
|
|
62
|
|
|
$publicKey = \substr($response, 28, 32); |
|
|
|
|
|
|
63
|
|
|
$signature = \substr($payload, -64); |
|
64
|
|
|
$payload = \substr($payload, 0, -64); |
|
65
|
|
|
$sigPubKey = \substr($payload, -32); |
|
66
|
|
|
$payload = \substr($payload, 0, -32); |
|
67
|
|
|
$body = \substr($payload, 60, \strlen($payload)); |
|
68
|
|
|
|
|
69
|
|
|
$decryptedPayload = $this->decrypt($body, $nonce); |
|
70
|
|
|
if (!$this->isSignatureValid($decryptedPayload, $signature, $sigPubKey)) { |
|
71
|
|
|
throw new InvalidSignatureException; |
|
72
|
|
|
} |
|
73
|
|
|
|
|
74
|
|
|
return $decryptedPayload; |
|
75
|
|
|
} |
|
76
|
|
|
|
|
77
|
|
|
if ($nonce === null) { |
|
78
|
|
|
throw new InvalidArgumentException('Nonce is required to decrypt v1 requests.'); |
|
79
|
|
|
} |
|
80
|
|
|
|
|
81
|
|
|
return $this->decryptBody($response, $nonce); |
|
82
|
|
|
} |
|
83
|
|
|
|
|
84
|
|
|
/** |
|
85
|
|
|
* Decrypts a given response with a nonce |
|
86
|
|
|
* This will return the decrypted string of decrypt was successful, and false otherwise |
|
87
|
|
|
* |
|
88
|
|
|
* @param string $response The encrypted HTTP response, as a multi-byte string |
|
89
|
|
|
* @param string $nonce The 32 byte nonce |
|
90
|
|
|
* @return string |
|
91
|
|
|
* |
|
92
|
|
|
* @throws InvalidArguementException |
|
93
|
|
|
*/ |
|
94
|
|
|
private function decryptBody(string $response, string $nonce) : string |
|
95
|
|
|
{ |
|
96
|
|
|
try { |
|
97
|
|
|
return \sodium_crypto_box_open( |
|
98
|
|
|
$response, |
|
99
|
|
|
$nonce, |
|
100
|
|
|
$this->keypair |
|
101
|
|
|
); |
|
102
|
|
|
} catch (SodiumException $e) { |
|
103
|
|
|
throw new InvalidArgumentException($e->getMessage()); |
|
104
|
|
|
} |
|
105
|
|
|
} |
|
106
|
|
|
|
|
107
|
|
|
/** |
|
108
|
|
|
* Returns true if the signature validates the response |
|
109
|
|
|
* |
|
110
|
|
|
* @param string $response The raw http response, after decoding |
|
111
|
|
|
* @param string $signature The raw multi-byte signature |
|
112
|
|
|
* @param string $publicKey The signing public key |
|
113
|
|
|
* @return bool |
|
114
|
|
|
* |
|
115
|
|
|
* @throws InvalidArguementException |
|
116
|
|
|
*/ |
|
117
|
|
|
public function isSignatureValid(string $response, string $signature, string $publicKey) : bool |
|
118
|
|
|
{ |
|
119
|
|
|
try { |
|
120
|
|
|
return \sodium_crypto_sign_verify_detached( |
|
121
|
|
|
$signature, |
|
122
|
|
|
$response, |
|
123
|
|
|
$publicKey |
|
124
|
|
|
); |
|
125
|
|
|
} catch (SodiumException $e) { |
|
126
|
|
|
throw new InvalidArgumentException($e->getMessage()); |
|
127
|
|
|
} |
|
128
|
|
|
} |
|
129
|
|
|
|
|
130
|
|
|
/** |
|
131
|
|
|
* Extracts the version from the response |
|
132
|
|
|
* |
|
133
|
|
|
* @param string $response The encrypted http response |
|
134
|
|
|
* @return int |
|
135
|
|
|
*/ |
|
136
|
|
|
private function getVersion(string $response) : int |
|
137
|
|
|
{ |
|
138
|
|
|
$header = \substr($response, 0, 4); |
|
139
|
|
|
if (\strtoupper(\unpack("h*", $header)[1]) === 'DE259002') { |
|
140
|
|
|
return 2; |
|
141
|
|
|
} |
|
142
|
|
|
|
|
143
|
|
|
return 1; |
|
144
|
|
|
} |
|
145
|
|
|
} |
|
146
|
|
|
|
ncryptf /
ncryptf-php
Loading history...