gmail-smtp / google-api-php-client / vendor / guzzlehttp / guzzle / src / Handler / ProxyEnvironment.php

ProxyEnvironment.php in Gmail SMTP trunk, at google-api-php-client/vendor/guzzlehttp/guzzle/src/Handler/ProxyEnvironment.php

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1	<?php
2
3	namespace GuzzleHttp\Handler;
4
5	/**
6	* Resolves proxy configuration from the process environment with the same
7	* semantics libcurl applies, so the cURL handlers can pin CURLOPT_PROXY and
8	* CURLOPT_NOPROXY explicitly and libcurl never reads the environment itself.
9	*
10	* @internal
11	*/
12	final class ProxyEnvironment
13	{
14	private function __construct()
15	{
16	}
17
18	/**
19	* Resolves the proxy to use for the given request scheme.
20	*
21	* The lookup mirrors libcurl for the http and https schemes the handlers
22	* accept: the lowercase scheme-specific variable first, its uppercase
23	* variant next (except for "http", where uppercase HTTP_PROXY is never
24	* read), then all_proxy/ALL_PROXY.
25	*
26	* @return string\|null The proxy to use; null when the environment
27	* configures none.
28	*/
29	public static function getProxyForScheme(string $scheme): ?string
30	{
31	$scheme = \strtolower($scheme);
32	$candidates = [$scheme.'_proxy'];
33	if ($scheme !== 'http') {
34	// Uppercase HTTP_PROXY is deliberately never consulted: a CGI
35	// request header "Proxy:" becomes HTTP_PROXY in the environment.
36	// See https://httpoxy.org for more information.
37	$candidates[] = \strtoupper($scheme).'_PROXY';
38	}
39	$candidates[] = 'all_proxy';
40	$candidates[] = 'ALL_PROXY';
41
42	foreach ($candidates as $name) {
43	$value = self::getenv($name);
44	if ($value !== null) {
45	return $value;
46	}
47	}
48
49	return null;
50	}
51
52	/**
53	* @return string\|null The no-proxy list; null when nothing is set.
54	*/
55	public static function getNoProxy(): ?string
56	{
57	foreach (['no_proxy', 'NO_PROXY'] as $name) {
58	$value = self::getenv($name);
59	if ($value !== null) {
60	return $value;
61	}
62	}
63
64	return null;
65	}
66
67	/**
68	* Splits a no_proxy environment value into matchable entries.
69	*
70	* Mirrors libcurl's tokenization: entries may be separated by commas or
71	* blanks, and a single leading dot is ignored, so ".example.com" bypasses
72	* example.com and its subdomains exactly as a bare domain entry does.
73	*
74	* @return string[]
75	*/
76	public static function splitNoProxy(string $noProxy): array
77	{
78	$entries = [];
79
80	foreach (\preg_split('/[\s,]+/', $noProxy) ?: [] as $entry) {
81	if ($entry !== '' && $entry[0] === '.') {
82	$entry = \substr($entry, 1);
83	}
84
85	if ($entry !== '') {
86	$entries[] = $entry;
87	}
88	}
89
90	return $entries;
91	}
92
93	private static function getenv(string $name): ?string
94	{
95	// Windows environment variables are case-insensitive, so the
96	// lowercase-only httpoxy defence does not hold there. Outside the
97	// CLI SAPI on Windows, environment proxies are not resolved at all
98	// (a safe-side divergence from libcurl).
99	if (\PHP_OS_FAMILY === 'Windows' && \PHP_SAPI !== 'cli') {
100	return null;
101	}
102
103	// local_only: the OS environment and putenv() only - the same
104	// environ(7) libcurl reads. SAPI request environments such as
105	// fastcgi_param or SetEnv are deliberately excluded.
106	$value = \getenv($name, true);
107
108	// libcurl's GetEnv (lib/getenv.c) treats variables set to an empty
109	// string as unset on every version, so the lookup falls through to
110	// the next candidate.
111	return $value === false \|\| $value === '' ? null : $value;
112	}
113	}
114