1
|
|
|
<?php |
2
|
|
|
|
3
|
|
|
declare(strict_types=1); |
4
|
|
|
|
5
|
|
|
namespace SimpleSAML\XMLSecurity\Alg; |
6
|
|
|
|
7
|
|
|
use SimpleSAML\Assert\Assert; |
8
|
|
|
use SimpleSAML\XMLSecurity\Exception\BlacklistedAlgorithmException; |
9
|
|
|
use SimpleSAML\XMLSecurity\Exception\UnsupportedAlgorithmException; |
10
|
|
|
use SimpleSAML\XMLSecurity\Key\KeyInterface; |
11
|
|
|
|
12
|
|
|
/** |
13
|
|
|
* An abstract class implementing an algorithm factory. |
14
|
|
|
* |
15
|
|
|
* Extending classes MUST declare two static properties: |
16
|
|
|
* |
17
|
|
|
* - $cache: an associative array holding algorithm IDs as the keys, and class names implementing those algorithms as |
18
|
|
|
* the value. |
19
|
|
|
* - $initialized: a boolean telling whether this factory has been initialized (a constructor has been called) or not. |
20
|
|
|
* |
21
|
|
|
* @package simplesamlphp/xml-security |
22
|
|
|
*/ |
23
|
|
|
abstract class AbstractAlgorithmFactory |
24
|
|
|
{ |
25
|
|
|
/** |
26
|
|
|
* A cache of algorithm implementations indexed by algorithm ID. |
27
|
|
|
* |
28
|
|
|
* @var string[] |
29
|
|
|
*/ |
30
|
|
|
protected static array $cache = []; |
31
|
|
|
|
32
|
|
|
/** |
33
|
|
|
* Whether the factory has been initialized or not. |
34
|
|
|
* |
35
|
|
|
* @var bool |
36
|
|
|
*/ |
37
|
|
|
protected static bool $initialized = false; |
38
|
|
|
|
39
|
|
|
|
40
|
|
|
/** |
41
|
|
|
* Build a factory that creates algorithms. |
42
|
|
|
* |
43
|
|
|
* @param string[]|null $blacklist A list of algorithms forbidden for their use. |
44
|
|
|
* @param string[]|null $defaults A list of known implementations. |
45
|
|
|
*/ |
46
|
|
|
public function __construct( |
47
|
|
|
protected ?array $blacklist = null, |
48
|
|
|
?array $defaults = null, |
49
|
|
|
) { |
50
|
|
|
// initialize the cache for supported algorithms per known implementation |
51
|
|
|
if (!static::$initialized && $defaults !== null) { |
52
|
|
|
foreach ($defaults as $algorithm) { |
53
|
|
|
/** @var \SimpleSAML\XMLSecurity\Alg\AlgorithmInterface $algorithm */ |
54
|
|
|
foreach ($algorithm::getSupportedAlgorithms() as $algId) { |
55
|
|
|
if (array_key_exists($algId, static::$cache)) { |
56
|
|
|
/* |
57
|
|
|
* If the key existed before initialization, that means someone registered a handler for this |
58
|
|
|
* algorithm, so we should respect that and skip registering the default here. |
59
|
|
|
*/ |
60
|
|
|
continue; |
61
|
|
|
} |
62
|
|
|
static::$cache[$algId] = $algorithm; |
63
|
|
|
} |
64
|
|
|
} |
65
|
|
|
static::$initialized = true; |
66
|
|
|
} |
67
|
|
|
} |
68
|
|
|
|
69
|
|
|
|
70
|
|
|
/** |
71
|
|
|
* Get a new object implementing the given algorithm. |
72
|
|
|
* |
73
|
|
|
* @param string $algId The identifier of the algorithm desired. |
74
|
|
|
* @param \SimpleSAML\XMLSecurity\Key\KeyInterface $key The key to use with the given algorithm. |
75
|
|
|
* |
76
|
|
|
* @return \SimpleSAML\XMLSecurity\Alg\AlgorithmInterface An object implementing the given algorithm. |
77
|
|
|
* |
78
|
|
|
* @throws \SimpleSAML\XMLSecurity\Exception\InvalidArgumentException If an error occurs, e.g. the given algorithm |
79
|
|
|
* is blacklisted, unknown or the given key is not suitable for it. |
80
|
|
|
*/ |
81
|
|
|
public function getAlgorithm(string $algId, KeyInterface $key): AlgorithmInterface |
82
|
|
|
{ |
83
|
|
|
Assert::false( |
84
|
|
|
in_array($algId, $this->blacklist, true), |
|
|
|
|
85
|
|
|
sprintf('Blacklisted algorithm: \'%s\'.', $algId), |
86
|
|
|
BlacklistedAlgorithmException::class, |
87
|
|
|
); |
88
|
|
|
Assert::keyExists( |
89
|
|
|
static::$cache, |
90
|
|
|
$algId, |
91
|
|
|
sprintf('Unknown or unsupported algorithm: \'%s\'.', $algId), |
92
|
|
|
UnsupportedAlgorithmException::class, |
93
|
|
|
); |
94
|
|
|
|
95
|
|
|
return new static::$cache[$algId]($key, $algId); |
96
|
|
|
} |
97
|
|
|
|
98
|
|
|
|
99
|
|
|
/** |
100
|
|
|
* Get the name of the abstract class our algorithm implementations must extend. |
101
|
|
|
* |
102
|
|
|
* @return string |
103
|
|
|
*/ |
104
|
|
|
abstract protected static function getExpectedParent(): string; |
105
|
|
|
|
106
|
|
|
|
107
|
|
|
/** |
108
|
|
|
* Register an implementation of some algorithm(s) for its use. |
109
|
|
|
* |
110
|
|
|
* @param string $className |
111
|
|
|
*/ |
112
|
|
|
public static function registerAlgorithm(string $className): void |
113
|
|
|
{ |
114
|
|
|
$parent = static::getExpectedParent(); |
115
|
|
|
Assert::subclassOf( |
116
|
|
|
$className, |
117
|
|
|
$parent, |
118
|
|
|
'Cannot register algorithm "' . $className . '", must implement ' . $parent . '.', |
119
|
|
|
); |
120
|
|
|
|
121
|
|
|
/** @var \SimpleSAML\XMLSecurity\Alg\AlgorithmInterface $className */ |
122
|
|
|
foreach ($className::getSupportedAlgorithms() as $algId) { |
123
|
|
|
static::$cache[$algId] = $className; |
124
|
|
|
} |
125
|
|
|
} |
126
|
|
|
} |
127
|
|
|
|