EncryptHelper::coincidenceCount() - Code Metrics - Inspection of "ciphersweet 3.0 support" - lekoala/silverstripe-encrypt - Measure and Improve Code Quality continuously with Scrutinizer

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by Thomas

created 2021-07-02 15:02 UTC

EncryptHelper::coincidenceCount() A

↳ Parent: EncryptHelper

Complexity

Conditions	2
Paths	2

Size

Total Lines	8
Code Lines	5

Duplication

Lines	0
Ratio	0 %

Importance

Changes	1
Bugs	0	Features	1

Metric	Value
eloc	5
c	1
b	0
f	1
dl	0
loc	8
rs	10
cc	2
nc	2
nop	2

<?php

namespace LeKoala\Encrypt;

use Exception;
use SilverStripe\Assets\File;
use ParagonIE\ConstantTime\Hex;
use SilverStripe\Core\Environment;
use ParagonIE\CipherSweet\CipherSweet;
use SilverStripe\ORM\FieldType\DBText;
use SilverStripe\ORM\FieldType\DBVarchar;
use SilverStripe\ORM\FieldType\DBHTMLText;
use ParagonIE\CipherSweet\Backend\BoringCrypto;
use ParagonIE\CipherSweet\Backend\FIPSCrypto;
use ParagonIE\CipherSweet\Backend\ModernCrypto;
use ParagonIE\CipherSweet\Contract\BackendInterface;
use ParagonIE\CipherSweet\KeyProvider\StringProvider;

/**
 * @link https://ciphersweet.paragonie.com/php
 * @link https://paragonie.com/blog/2017/05/building-searchable-encrypted-databases-with-php-and-sql
 * @link https://paragonie.com/book/pecl-libsodium/read/09-recipes.md
 */
class EncryptHelper
{
    const BORING = "brng";
    const MODERN = "nacl";
    const FIPS = "fips";

    /**
     * @var CipherSweet
     */
    protected static $ciphersweet;

    /**
     * @var array
     */
    protected static $field_cache = [];

    /**
     * @var string
     */
    protected static $forcedEncryption = null;

    /**
     * @param string $forcedEncryption brng|nacl|fips
     * @return void
     */
    public static function setForcedEncryption($forcedEncryption)
    {
        self::$forcedEncryption = $forcedEncryption;
    }

    /**
     * Attempting to pass a key of an invalid size (i.e. not 256-bit) will result in a CryptoOperationException being thrown.
     * The recommended way to generate a key is to use this method
     *
     * @return string Something like 4e1c44f87b4cdf21808762970b356891db180a9dd9850e7baf2a79ff3ab8a2fc
     */
    public static function generateKey()
    {
        return Hex::encode(random_bytes(32));
    }

    /**
     * Get app encryption key
     * Encryption key should be provided in your $_ENV or .env file
     *
     * @return string
     */
    public static function getKey()
    {
        $key = Environment::getEnv('ENCRYPTION_KEY');
        if (!$key) {
            $key = self::generateKey();
            throw new Exception("Please define an ENCRYPTION_KEY in your environment. You can use this one: $key");
        }
        return $key;
    }

    /**
     * @return StringProvider
     */
    public static function getProviderWithKey()
    {
        return new StringProvider(
            self::getKey()
        );
    }

    /**
     * @return BackendInterface
     */
    public static function getRecommendedBackend()
    {
        if (version_compare(phpversion(), '7.2', '<')) {
            return new FIPSCrypto();
        }
        return new BoringCrypto();
    }

    /**
     * @param string $encryption
     * @return BackendInterface
     */
    public static function getBackendForEncryption($encryption = null)
    {
        if (!$encryption) {
            return self::getRecommendedBackend();
        }
        switch ($encryption) {
            case self::BORING:
                return new BoringCrypto();
            case self::MODERN:
                return new ModernCrypto();
            case self::FIPS:
                return new FIPSCrypto();
        }
        throw new Exception("Unsupported encryption $encryption");
    }


    /**
     * @return CipherSweet
     */
    public static function getCipherSweet()
    {
        if (self::$ciphersweet) {
            return self::$ciphersweet;
        }
        $provider = self::getProviderWithKey();
        if (self::$forcedEncryption) {
            $backend = self::getBackendForEncryption(self::$forcedEncryption);
        } else {
            $backend = self::getRecommendedBackend();
        }
        self::$ciphersweet = new CipherSweet($provider, $backend);
        return self::$ciphersweet;
    }

    /**
     * @return BackendInterface
     */
    public static function getCipherSweetBackend()
    {
        return self::getCipherSweet()->getBackend();
    }

    /**
     * Check if a value is encrypted
     *
     * @param string $value
     * @return boolean
     */
    public static function isEncrypted($value)
    {
        $prefix = substr($value, 0, 5);
        return in_array($prefix, ["brng:", "nacl:", "fips:"]);
    }

    /**
     * @param string $value
     * @return boolean
     */
    public static function isFips($value)
    {
        if (strpos($value, 'fips:') === 0) {
            return true;
        }
        return false;
    }

    /**
     * @param string $value
     * @return boolean
     */
    public static function isNacl($value)
    {
        if (strpos($value, 'nacl:') === 0) {
            return true;
        }
        return false;
    }

    /**
     * @param string $value
     * @return boolean
     */
    public static function isBoring($value)
    {
        if (strpos($value, 'brng:') === 0) {
            return true;
        }
        return false;
    }

    /**
     * @param string $value
     * @return string
     */
    public static function getEncryption($value)
    {
        if (self::isBoring($value)) {
            return self::BORING;
        }
        if (self::isNacl($value)) {
            return self::MODERN;
        }
        if (self::isFips($value)) {
            return self::FIPS;
        }
        return false;

    }

    /**
     * Check if a field is encrypted on a class
     * This relies on a field class starting with Encrypted
     *
     * @param string $class
     * @param string $field
     * @return boolean
     */
    public static function isEncryptedField($class, $field)
    {
        $key = $class . '_' . $field;
        if (isset(self::$field_cache[$key])) {
            return self::$field_cache[$key];
        }

        $fields = $class::config()->db;

        if (isset($fields[$field])) {
            $dbClass = $fields[$field];
            self::$field_cache[$key] = strpos($dbClass, 'Encrypted') !== false;
        } else {
            self::$field_cache[$key] = false;
        }
        return self::$field_cache[$key];
    }

    /**
     * A simple encryption
     * @param string $value
     * @return string
     */
    public static function encrypt($value)
    {
        // Do not encrypt twice
        $encryption = self::getEncryption($value);
        if ($encryption) {
            return $value;
        }
        $provider = self::getProviderWithKey();
        $backend = self::getBackendForEncryption($encryption);
        return $backend->encrypt($value, $provider->getSymmetricKey());
    }

    /**
     * A simple decryption
     * @param string $value
     * @return string
     */
    public static function decrypt($value)
    {
        // Only decrypt what we can decrypt
        $encryption = self::getEncryption($value);
        if (!$encryption) {
            return $value;
        }
        $provider = self::getProviderWithKey();
        $backend =  self::getBackendForEncryption($encryption);
        return $backend->decrypt($value, $provider->getSymmetricKey());
    }

    /**
     * Return a map of fields with their encrypted counterpart
     *
     * @return array
     */
    public static function mapEncryptionDBField()
    {
        return [
            DBHTMLText::class => EncryptedDBHTMLText::class,
            DBText::class => EncryptedDBText::class,
            DBVarchar::class => EncryptedDBVarchar::class,
        ];
    }

    /**
     * Compute Blind Index Information Leaks
     *
     * @link https://ciphersweet.paragonie.com/security
     * @param array $indexes
     * @param int $R
     * @return float
     */
    public static function coincidenceCount(array $indexes, $R)
    {
        $exponent = 0;
        $count = count($indexes);
        for ($i = 0; $i < $count; ++$i) {
            $exponent += min($indexes[$i]['L'], $indexes[$i]['K']);
        }
        return (float) max(1, $R) / pow(2, $exponent);
    }

    /**
     * Send a decrypted file
     *
     * @param File $file
     * @return void
     */
    public static function sendEncryptedFile(File $file)
    {
        header('Content-disposition: attachment; filename="' . basename($file->getFilename()) . '"');
        header('Content-type: application/octetstream');
        header('Pragma: no-cache');
        header('Expires: 0');
        $file->sendDecryptedFile();
    }
}


1			<?php
2
3			namespace LeKoala\Encrypt;
4
5			use Exception;
6			use SilverStripe\Assets\File;
7			use ParagonIE\ConstantTime\Hex;
8			use SilverStripe\Core\Environment;
9			use ParagonIE\CipherSweet\CipherSweet;
10			use SilverStripe\ORM\FieldType\DBText;
11			use SilverStripe\ORM\FieldType\DBVarchar;
12			use SilverStripe\ORM\FieldType\DBHTMLText;
13			use ParagonIE\CipherSweet\Backend\BoringCrypto;
14			use ParagonIE\CipherSweet\Backend\FIPSCrypto;
15			use ParagonIE\CipherSweet\Backend\ModernCrypto;
16			use ParagonIE\CipherSweet\Contract\BackendInterface;
17			use ParagonIE\CipherSweet\KeyProvider\StringProvider;
18
19			/**
20			* @link https://ciphersweet.paragonie.com/php
21			* @link https://paragonie.com/blog/2017/05/building-searchable-encrypted-databases-with-php-and-sql
22			* @link https://paragonie.com/book/pecl-libsodium/read/09-recipes.md
23			*/
24			class EncryptHelper
25			{
26			const BORING = "brng";
27			const MODERN = "nacl";
28			const FIPS = "fips";
29
30			/**
31			* @var CipherSweet
32			*/
33			protected static $ciphersweet;
34
35			/**
36			* @var array
37			*/
38			protected static $field_cache = [];
39
40			/**
41			* @var string
42			*/
43			protected static $forcedEncryption = null;
44
45			/**
46			* @param string $forcedEncryption brng\|nacl\|fips
47			* @return void
48			*/
49			public static function setForcedEncryption($forcedEncryption)
50			{
51			self::$forcedEncryption = $forcedEncryption;
52			}
53
54			/**
55			* Attempting to pass a key of an invalid size (i.e. not 256-bit) will result in a CryptoOperationException being thrown.
56			* The recommended way to generate a key is to use this method
57			*
58			* @return string Something like 4e1c44f87b4cdf21808762970b356891db180a9dd9850e7baf2a79ff3ab8a2fc
59			*/
60			public static function generateKey()
61			{
62			return Hex::encode(random_bytes(32));
63			}
64
65			/**
66			* Get app encryption key
67			* Encryption key should be provided in your $_ENV or .env file
68			*
69			* @return string
70			*/
71			public static function getKey()
72			{
73			$key = Environment::getEnv('ENCRYPTION_KEY');
74			if (!$key) {
75			$key = self::generateKey();
76			throw new Exception("Please define an ENCRYPTION_KEY in your environment. You can use this one: $key");
77			}
78			return $key;
79			}
80
81			/**
82			* @return StringProvider
83			*/
84			public static function getProviderWithKey()
85			{
86			return new StringProvider(
87			self::getKey()
88			);
89			}
90
91			/**
92			* @return BackendInterface
93			*/
94			public static function getRecommendedBackend()
95			{
96			if (version_compare(phpversion(), '7.2', '<')) {
97			return new FIPSCrypto();
98			}
99			return new BoringCrypto();
100			}
101
102			/**
103			* @param string $encryption
104			* @return BackendInterface
105			*/
106			public static function getBackendForEncryption($encryption = null)
107			{
108			if (!$encryption) {
109			return self::getRecommendedBackend();
110			}
111			switch ($encryption) {
112			case self::BORING:
113			return new BoringCrypto();
114			case self::MODERN:
115			return new ModernCrypto();
116			case self::FIPS:
117			return new FIPSCrypto();
118			}
119			throw new Exception("Unsupported encryption $encryption");
120			}
121
122
123			/**
124			* @return CipherSweet
125			*/
126			public static function getCipherSweet()
127			{
128			if (self::$ciphersweet) {
129			return self::$ciphersweet;
130			}
131			$provider = self::getProviderWithKey();
132			if (self::$forcedEncryption) {
133			$backend = self::getBackendForEncryption(self::$forcedEncryption);
134			} else {
135			$backend = self::getRecommendedBackend();
136			}
137			self::$ciphersweet = new CipherSweet($provider, $backend);
138			return self::$ciphersweet;
139			}
140
141			/**
142			* @return BackendInterface
143			*/
144			public static function getCipherSweetBackend()
145			{
146			return self::getCipherSweet()->getBackend();
147			}
148
149			/**
150			* Check if a value is encrypted
151			*
152			* @param string $value
153			* @return boolean
154			*/
155			public static function isEncrypted($value)
156			{
157			$prefix = substr($value, 0, 5);
158			return in_array($prefix, ["brng:", "nacl:", "fips:"]);
159			}
160
161			/**
162			* @param string $value
163			* @return boolean
164			*/
165			public static function isFips($value)
166			{
167			if (strpos($value, 'fips:') === 0) {
168			return true;
169			}
170			return false;
171			}
172
173			/**
174			* @param string $value
175			* @return boolean
176			*/
177			public static function isNacl($value)
178			{
179			if (strpos($value, 'nacl:') === 0) {
180			return true;
181			}
182			return false;
183			}
184
185			/**
186			* @param string $value
187			* @return boolean
188			*/
189			public static function isBoring($value)
190			{
191			if (strpos($value, 'brng:') === 0) {
192			return true;
193			}
194			return false;
195			}
196
197			/**
198			* @param string $value
199			* @return string
200			*/
201			public static function getEncryption($value)
202			{
203			if (self::isBoring($value)) {
204			return self::BORING;
205			}
206			if (self::isNacl($value)) {
207			return self::MODERN;
208			}
209			if (self::isFips($value)) {
210			return self::FIPS;
211			}
212			return false;
			0 ignored issues – show Bug Best Practice introduced 2021-07-02 15:05 UTC by Report Bug Copy Issue Report The expression `return false` returns the type `false` which is incompatible with the documented return type `string`. Loading history...
213			}
214
215			/**
216			* Check if a field is encrypted on a class
217			* This relies on a field class starting with Encrypted
218			*
219			* @param string $class
220			* @param string $field
221			* @return boolean
222			*/
223			public static function isEncryptedField($class, $field)
224			{
225			$key = $class . '_' . $field;
226			if (isset(self::$field_cache[$key])) {
227			return self::$field_cache[$key];
228			}
229
230			$fields = $class::config()->db;
231
232			if (isset($fields[$field])) {
233			$dbClass = $fields[$field];
234			self::$field_cache[$key] = strpos($dbClass, 'Encrypted') !== false;
235			} else {
236			self::$field_cache[$key] = false;
237			}
238			return self::$field_cache[$key];
239			}
240
241			/**
242			* A simple encryption
243			* @param string $value
244			* @return string
245			*/
246			public static function encrypt($value)
247			{
248			// Do not encrypt twice
249			$encryption = self::getEncryption($value);
250			if ($encryption) {
251			return $value;
252			}
253			$provider = self::getProviderWithKey();
254			$backend = self::getBackendForEncryption($encryption);
255			return $backend->encrypt($value, $provider->getSymmetricKey());
256			}
257
258			/**
259			* A simple decryption
260			* @param string $value
261			* @return string
262			*/
263			public static function decrypt($value)
264			{
265			// Only decrypt what we can decrypt
266			$encryption = self::getEncryption($value);
267			if (!$encryption) {
268			return $value;
269			}
270			$provider = self::getProviderWithKey();
271			$backend = self::getBackendForEncryption($encryption);
272			return $backend->decrypt($value, $provider->getSymmetricKey());
273			}
274
275			/**
276			* Return a map of fields with their encrypted counterpart
277			*
278			* @return array
279			*/
280			public static function mapEncryptionDBField()
281			{
282			return [
283			DBHTMLText::class => EncryptedDBHTMLText::class,
284			DBText::class => EncryptedDBText::class,
285			DBVarchar::class => EncryptedDBVarchar::class,
286			];
287			}
288
289			/**
290			* Compute Blind Index Information Leaks
291			*
292			* @link https://ciphersweet.paragonie.com/security
293			* @param array $indexes
294			* @param int $R
295			* @return float
296			*/
297			public static function coincidenceCount(array $indexes, $R)
298			{
299			$exponent = 0;
300			$count = count($indexes);
301			for ($i = 0; $i < $count; ++$i) {
302			$exponent += min($indexes[$i]['L'], $indexes[$i]['K']);
303			}
304			return (float) max(1, $R) / pow(2, $exponent);
305			}
306
307			/**
308			* Send a decrypted file
309			*
310			* @param File $file
311			* @return void
312			*/
313			public static function sendEncryptedFile(File $file)
314			{
315			header('Content-disposition: attachment; filename="' . basename($file->getFilename()) . '"');
316			header('Content-type: application/octetstream');
317			header('Pragma: no-cache');
318			header('Expires: 0');
319			$file->sendDecryptedFile();
320			}
321			}
322

lekoala / silverstripe-encrypt

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EncryptHelper::coincidenceCount() A

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