Passed
Push — master ( c0a3a7...3b84a4 )
by Jeroen
58:51
created

SiteSecret::fromConfig()   A

Complexity

Conditions 2
Paths 2

Size

Total Lines 10
Code Lines 5

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 6
CRAP Score 2

Importance

Changes 0
Metric Value
cc 2
eloc 5
nc 2
nop 1
dl 0
loc 10
rs 9.4285
c 0
b 0
f 0
ccs 6
cts 6
cp 1
crap 2
1
<?php
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namespace Elgg\Database;
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use Elgg\Config as ElggConfig;
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use Elgg\Database;
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use ElggCrypto;
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/**
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 * Manages a site-specific secret key, encoded as a 32 byte string "secret"
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 *
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 * The key can have two formats:
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 *   - Since 1.8.17 all keys generated are Base64URL-encoded with the 1st character set to "z" so that
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 *     the format can be recognized. With one character lost, this makes the keys effectively 186 bits.
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 *   - Before 1.8.17 keys were hex-encoded (128 bits) but created from insufficiently random sources.
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 *
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 * The hex keys were created with rand() as the only decent source of entropy (the site's creation time
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 * is not too difficult to find). As such, systems with a low getrandmax() value created particularly
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 * weak keys. You can check key string using getStrength().
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 *
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 * @access private
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 * @since  1.10.0
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 */
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class SiteSecret {
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	const CONFIG_KEY = '__site_secret__';
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	/**
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	 * Constructor
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	 *
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	 * @param string $key Site key (32 hex chars, or "z" and 31 base64 chars)
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	 */
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	public function __construct($key) {
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		$this->key = $key;
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	}
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	/**
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	 * @var string
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	 */
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	private $key;
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	/**
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	 * Returns the site secret.
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	 *
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	 * Used to generate difficult to guess hashes for sessions and action tokens.
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	 *
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	 * @param bool $raw If true, a binary key will be returned
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	 *
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	 * @return string Site secret.
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	 * @access private
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	 */
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	public function get($raw = false) {
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		if (!$this->key) {
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			throw new \RuntimeException('Secret key is not set');
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		}
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		if (!$raw) {
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			return $this->key;
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		}
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		// try to return binary key
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		if ($this->key[0] === 'z') {
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			// new keys are "z" + base64URL
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			$base64 = strtr(substr($this->key, 1), '-_', '+/');
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			$key = base64_decode($base64);
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			if ($key !== false) {
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				return $key;
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			}
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			// on failure, at least return string key :/
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			return $this->key;
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		}
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		// old keys are hex
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		return hex2bin($this->key);
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	}
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	/**
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	 * Get the strength of the site secret
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	 *
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	 * If "weak" or "moderate" is returned, this assumes we're running on the same system that created
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	 * the key.
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	 *
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	 * @return string "strong", "moderate", or "weak"
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	 * @access private
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	 */
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	public function getStrength() {
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		$secret = $this->get();
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		if ($secret[0] !== 'z') {
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			$rand_max = getrandmax();
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			if ($rand_max < pow(2, 16)) {
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				return 'weak';
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			}
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			if ($rand_max < pow(2, 32)) {
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				return 'moderate';
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			}
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		}
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		return 'strong';
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	}
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	/**
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	 * Initialise the site secret (32 bytes: "z" to indicate format + 186-bit key in Base64 URL)
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	 * and save to config table.
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	 *
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	 * Used during installation or regeneration.
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	 *
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	 * @param ElggCrypto  $crypto Crypto service
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	 * @param ConfigTable $table  Config table
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	 * @return SiteSecret
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	 */
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	public static function regenerate(ElggCrypto $crypto, ConfigTable $table) {
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		$key = 'z' . $crypto->getRandomString(31);
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		$table->set(self::CONFIG_KEY, $key);
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		return new self($key);
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	}
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	/**
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	 * Create from config/storage.
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	 *
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	 * @param ConfigTable $table Config table
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	 *
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	 * @return SiteSecret
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	 * @throws \InstallationException
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	 */
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	public static function fromDatabase(ConfigTable $table) {
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		$key = $table->get(self::CONFIG_KEY);
0 ignored issues
show
Bug introduced by Steve Clay
Are you sure the assignment to $key is correct as $table->get(self::CONFIG_KEY) targeting Elgg\Database\ConfigTable::get() seems to always return null.

This check looks for function or method calls that always return null and whose return value is assigned to a variable.

class A
{
    function getObject()
    {
        return null;
    }

}

$a = new A();
$object = $a->getObject();

The method getObject() can return nothing but null, so it makes no sense to assign that value to a variable.

The reason is most likely that a function or method is imcomplete or has been reduced for debug purposes.

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128 1
		if (!$key) {
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			throw new \InstallationException('Site secret is not in the config table.');
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		}
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		return new self($key);
0 ignored issues
show
Bug introduced by Steve Clay
$key of type void is incompatible with the type string expected by parameter $key of Elgg\Database\SiteSecret::__construct(). ( Ignorable by Annotation )

If this is a false-positive, you can also ignore this issue in your code via the ignore-type  annotation

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		return new self(/** @scrutinizer ignore-type */ $key);
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	}
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	/**
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	 * Create from a config value. If successful, the value will be erased from config.
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	 *
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	 * @param ElggConfig $config Config
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	 *
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	 * @return SiteSecret|false
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	 */
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	public static function fromConfig(ElggConfig $config) {
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		$key = $config->{self::CONFIG_KEY};
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		if (!$key) {
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			return false;
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		}
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		// Don't leave this sitting around in config, in case it gets dumped
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		unset($config->{self::CONFIG_KEY});
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		return new self($key);
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	}
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}
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