SecureString::encrypt() - Code Metrics - Inspection of "Add a more robust salt generator for crypt." - vanilla/garden - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( b3af43...6273ca )

by Todd

created 2016-01-04 16:46 UTC

SecureString::encrypt() A

↳ Parent: SecureString

Complexity

Conditions	3
Paths	4

Size

Total Lines	16
Code Lines	9

Duplication

Lines	16
Ratio	100 %

Code Coverage

Tests	8
CRAP Score	3.0123

Importance

Changes	1
Bugs	0	Features	1

Metric	Value
c	1
b	0
f	1
dl	16
loc	16
ccs	8
cts	9
cp	0.8889
rs	9.4286
cc	3
eloc	9
nc	4
nop	5
crap	3.0123

<?php
/**
 * @author Todd Burry <[email protected]>
 * @copyright 2009-2014 Vanilla Forums Inc.
 * @license MIT
 */

namespace Garden;


/**
 * A class that provides functionality for encrypting and signing strings and then decoding those secure strings.
 */
class SecureString {
    const SEP = '.';
    const EOS = '-';
    const STRICT = 'strict';

    protected $timestampExpiry;

    /**
     * Initialize an instance of the {@link SecureString} class.
     */
    public function __construct() {
        $this->timestampExpiry = strtotime('1 day', 0);
    }

    /**
     * Get or set the timestamp expiry in seconds.
     *
     * @param int $value Set a new expiry value in seconds.
     * @return int Returns the current timestamp expiry.
     */
    public function timestampExpiry($value = 0) {
        if ($value) {
            $this->timestampExpiry = $value;
        }
        return $this->timestampExpiry;
    }

    /**
     * Encode a string using a secure specification.
     *
     * @param mixed $data The data to encode. This must be data that supports json serialization.
     * @param array $spec An array specifying how the string should be encoded.
     * The array should be in the form ['spec1' => 'password', 'spec2' => 'password'].
     * @param bool $throw Whether or not to throw an exception on error.
     * @return string|null Returns the encoded string or null if there is an error.
     */
    public function encode($data, array $spec, $throw = false) {
        $str = json_encode($data, JSON_UNESCAPED_SLASHES);

        $first = true;
        foreach ($spec as $name => $password) {
            if ($name === self::STRICT) {
                // Strict is just an option so continue.
                continue;
            }

            $supported = $this->supportedInfo($name, $throw);
            if ($supported === null) {
                return null;
            }

            list($encode,, $method, $encodeFirst) = $supported;

            if ($first) {
                if ($encodeFirst) {
                    $str = static::base64urlEncode($str);
                }
                $this->pushString($str, self::EOS);
            }

            switch ($encode) {

                case 'encrypt':
                    $str = $this->encrypt($str, $method, $password, '', $throw);
                    break;
                case 'hmac':
                    $str = $this->hmac($str, $method, $password, 0, $throw);
                    break;
                default:
                    return $this->exception($throw, "Invalid method $encode.", 500);

            }
            // Return on error.
            if (!$str) {
                return null;
            }

            $this->pushString($str, $name);

            $first = false;
        }

        return $str;
    }

    /**
     * Decode a string that was encoded using {@link SecureString::encode()}.
     *
     * @param string $str The encoded string.
     * @param array $spec An array specifying how the string should be encoded.
     * @param bool $throw Whether or not to throw an exception on error.
     * @return string|null Returns the decoded string or null of there was a problem.
     */
    public function decode($str, array $spec, $throw = false) {
        $decodeFirst = false;
        $wstr = $str; // wstr means working string
        $used = [];

        $strict = true;
        if (array_key_exists(self::STRICT, $spec)) {
            $strict = (bool)$spec[self::STRICT];
            unset($spec[self::STRICT]);
        }

        while ($token = $this->popString($wstr)) {
            if ($token === self::EOS) {
                if ($decodeFirst) {
                    $wstr = static::base64urlDecode($wstr);
                }
                break;
            }

            try {
                $supported = $this->supportedInfo($token, true);
            } catch (\Exception $ex) {
                return $this->exception($throw, $ex->getMessage(), 403);

            }

            if (!isset($spec[$token])) {
                return $this->exception($throw, "You did not provide a password for $token.", 403);

            }
            $password = $spec[$token];
            array_unshift($used, $token);

            list(, $decode, $method, $decodeFirst) = $supported;

            switch ($decode) {

                case 'decrypt':
                    $wstr = $this->decrypt($wstr, $method, $password, $throw);
                    break;
                case 'verifyHmac':
                    $wstr = $this->verifyHmac($wstr, $method, $password, $throw);
                    break;
                default:
                    return $this->exception($throw, "Invalid method $decode.", 500);

            }

            if ($wstr === null) {
                return null;
            }
        }

        // Make sure that the string was secured at all.
        if ($strict && array_keys($spec) != $used) {
            return $this->exception($throw, 'The string is not fully secure.', 403);

        } elseif (empty($used)) {
            return $this->exception($throw, 'The string is not secure.', 403);

        }

        $data = json_decode($wstr, true);
        if ($data === null) {
            return $this->exception($throw, 'The final string is not valid json.', 403);

        }

        return $data;
    }

    /**
     * Generate a random string suitable for use as an encryption or signature key.
     *
     * @param int $len The number of characters in the key.
     * @return string Returns a base64url encoded string representing the random key.
     */
    public static function generateRandomKey($len = 32) {
        $bytes = ceil($len * 3 / 4);

        return substr(self::base64urlEncode(openssl_random_pseudo_bytes($bytes)), 0, $len);
    }

    /**
     * Base64 Encode a string, but make it suitable to be passed in a url.
     *
     * @param string $str The string to encode.
     * @return string The encoded string.
     */
    protected static function base64urlEncode($str) {
        return trim(strtr(base64_encode($str), '+/', '-_'), '=');
    }

    /**
     * Decode a string that was encoded using base64UrlEncode().
     *
     * @param string $str The encoded string.
     * @return string The decoded string.
     */
    protected static function base64urlDecode($str) {
        return base64_decode(strtr($str, '-_', '+/'));
    }

    /**
     * Encrypt a string with {@link openssl_encrypt()}.
     *
     * @param string $str The string to encrypt.
     * @param string $method The encryption cipher.
     * @param string $password The encryption password.
     * @param string $iv The input vector.
     * @param bool $throw Whether or not to throw an exception on error.
     * @return string Returns the encrypted string.
     */
    protected function encrypt($str, $method, $password, $iv = '', $throw = false) {

        if ($iv === '') {
            $iv = openssl_random_pseudo_bytes(openssl_cipher_iv_length($method));
        }
        // Encrypt the string.
        $encrypted = openssl_encrypt($str, $method, $password, OPENSSL_RAW_DATA, $iv);

        if ($encrypted === false) {
            return $this->exception($throw, "Error encrypting the string.", 400);

        }

        $str = static::base64urlEncode($encrypted);
        $this->pushString($str, static::base64urlEncode($iv));

        return $str;
    }

    /**
     * Decrypt a string with {@link openssl_decrypt()}.
     *
     * @param string $str The base64 url encoded encrypted string.
     * @param string $method The encryption cipher.
     * @param string $password The password to decyrpt the string.
     * @param bool $throw Whether or not to decode the string on exception.
     * @return string|null Returns the decrypted string or null on error.
     */
    protected function decrypt($str, $method, $password, $throw = false) {
        $iv = static::base64urlDecode($this->popString($str));
        $encrypted = static::base64urlDecode($this->popString($str));

        try {
            $decrypted = openssl_decrypt($encrypted, $method, $password, true, $iv);
        } catch (\Exception $ex) {
            return $this->exception($throw, "Error decrypting the string.", 403);
        }

        if ($decrypted === false) {
            return $this->exception($throw, "Error decrypting the string.", 403);
        }

        return $decrypted;
    }

    /**
     * Get information about a supported spec name.
     *
     * @param string $name The name of the spec.
     * @param bool $throw Whether or not throw an exception on error.
     * @return array|null Returns an array in the form [encode, decode, method, encodeFirst].
     * Returns null on error.
     */
    protected function supportedInfo($name, $throw = false) {
        switch ($name) {
            case 'aes128':
            case 'aes256':
                $cipher = 'aes-'.substr($name, 3).'-cbc';
                return ['encrypt', 'decrypt', $cipher, false];
            case 'hsha1':
            case 'hsha256':
                $hash = substr($name, 1);
                return ['hmac', 'verifyHmac', $hash, true];
        }
        return $this->exception($throw, "Spec $name not supported.", 400);
    }

    /**
     * Sign a string with hmac and a hash method.
     *
     * @param string $str The string to sign.
     * @param string $method The hash method used to sign the string.
     * @param string $password The password used to hmac hash the string with.
     * @param int $timestamp The timestamp used to sign the string with or 0 to use the current time.
     * @param bool $throw Whether or not the throw an exception on error.
     * @return string Returns the string with signing information or null on error.
     */
    protected function hmac($str, $method, $password, $timestamp = 0, $throw = false) {

        if ($timestamp === 0) {
            $timestamp = time();
        }
        // Add the timestamp to the string.
        static::pushString($str, $timestamp);

        // Sign the string.
        $signature = hash_hmac($method, $str, $password, true);
        if ($signature === false) {
            return $this->exception($throw, "Invalid hash method $method.", 400);

        }

        // Add the signature to the string.
        static::pushString($str, static::base64urlEncode($signature));

        return $str;
    }

    /**
     * Verify the signature on a secure string.
     *
     * @param string $str The string to verify.
     * @param string $method The hashing algorithm that the string was signed with.
     * @param string $password The password used to sign the string.
     * @param bool $throw Whether or not to throw an exeptio on error.
     * @return bool Returns the string without the signing information or null on error.
     */
    protected function verifyHmac($str, $method, $password, $throw = false) {
        // Grab the signature from the string.
        $signature = $this->popString($str);
        if (!$signature) {
''   == false // true
''   == null  // true
'ab' == false // false
'ab' == null  // false

// It is often better to use strict comparison
'' === false // false
'' === null  // false
            return $this->exception($throw, "The signature is missing.", 403);
        }
        $signature = static::base64urlDecode($signature);

        // Recalculate the signature to compare.
        $calcSignature = hash_hmac($method, $str, $password, true);

        if (strlen($signature) !== strlen($calcSignature)) {
            return $this->exception($throw, "The signature is invalid.", 403);
        }

        // Do a double hmac comparison to prevent timing attacks.
        // https://www.isecpartners.com/blog/2011/february/double-hmac-verification.aspx
        $dblSignature = hash_hmac($method, $signature, $password, true);
        $dblCalcSignature = hash_hmac($method, $calcSignature, $password, true);

        if ($dblSignature !== $dblCalcSignature) {
            return $this->exception($throw, "The signature is invalid.", 403);
        }

        // Grab the timestamp and verify it.
        $timestamp = $this->popString($str);
        if (!$this->verifyTimestamp($timestamp, $throw)) {
            return null;
        }

        return $str;
    }

    /**
     * Verify that a timestamp hasn't expired.
     *
     * @param string $timestamp The unix timestamp to verify.
     * @param bool $throw Whether or not to throw an exception on error.
     * @return bool Returns true if the timestamp is valid or false otherwise.
     */
    protected function verifyTimestamp($timestamp, $throw = false) {
        if (!is_numeric($timestamp)) {
            return (bool)$this->exception($throw, "Invalid timestamp.", 403);
        }
        $intTimestamp = (int)$timestamp;
        $now = time();
        if ($intTimestamp + $this->timestampExpiry <= $now) {
            return (bool)$this->exception($throw, "The timestamp has expired.", 403);
        }

        return true;
    }

    /**
     * Pop a string off of the end of an encoded secure string.
     *
     * @param string &$str The main string to pop.
     * @return string|null Returns the popped string or null if {@link $str} is empty.
     */
    protected function popString(&$str) {
        if ($str === '') {
            return null;
        }

        $pos = strrpos($str, '.');
        if ($pos !== false) {
            $result = substr($str, $pos + 1);
            $str = substr($str, 0, $pos);
        } else {
            $result = $str;
            $str = '';
        }
        return $result;
    }

    /**
     * Pushes a string on to the end of an encoded secure string.
     *
     * @param string &$str The main string to push to.
     * @param string|array $item The string or array of strings to push on to the end of {@link $str}.
     */
    protected function pushString(&$str, $item) {
        if ($str) {
            $str .= static::SEP;
        }
        $str .= implode(static::SEP, (array)$item);
    }

    /**
     * Throw an exception or return false.
     *
     * @param bool $throw Whether or not to throw an exception.
     * @param string $message The exception message.
     * @param int $code The exception code.
     * @return bool Returns false if {@link $throw} is false.
     * @throws \Exception Throws an exception with {@link $message} and {@link $code}.
     */
    protected function exception($throw, $message, $code) {
        if ($throw) {
            throw new \Exception($message, $code);
        }
        return null;
    }

    /**
     * Twiddle a value in an encoded secure string to another value.
     *
     * This method is mainly for testing so that an invalid string can be created.
     *
     * @param string $string A valid cookie to twiddle.
     * @param int $index The index of the new value.
     * @param string $value The new value. This will be base64url encoded.
     * @param bool $encode Whether or not to base64 url encode the value.
     * @return string Returns the new encoded cookie.
     */
    public function twiddle($string, $index, $value, $encode = false) {
        $parts = explode(static::SEP, $string);

        if ($encode) {
            $value = static::base64urlEncode($value);
        }
        $parts[$index] = $value;

        return implode(static::SEP, $parts);
    }
}


1			<?php
2			/**
3			* @author Todd Burry <[email protected]>
4			* @copyright 2009-2014 Vanilla Forums Inc.
5			* @license MIT
6			*/
7
8			namespace Garden;
9
10
11			/**
12			* A class that provides functionality for encrypting and signing strings and then decoding those secure strings.
13			*/
14			class SecureString {
15			const SEP = '.';
16			const EOS = '-';
17			const STRICT = 'strict';
18
19			protected $timestampExpiry;
20
21			/**
22			* Initialize an instance of the {@link SecureString} class.
23			*/
24	440		public function __construct() {
25	440		$this->timestampExpiry = strtotime('1 day', 0);
26	440		}
27
28			/**
29			* Get or set the timestamp expiry in seconds.
30			*
31			* @param int $value Set a new expiry value in seconds.
32			* @return int Returns the current timestamp expiry.
33			*/
34	1		public function timestampExpiry($value = 0) {
35	1		if ($value) {
36	1		$this->timestampExpiry = $value;
37			}
38	1		return $this->timestampExpiry;
39			}
40
41			/**
42			* Encode a string using a secure specification.
43			*
44			* @param mixed $data The data to encode. This must be data that supports json serialization.
45			* @param array $spec An array specifying how the string should be encoded.
46			* The array should be in the form ['spec1' => 'password', 'spec2' => 'password'].
47			* @param bool $throw Whether or not to throw an exception on error.
48			* @return string\|null Returns the encoded string or null if there is an error.
49			*/
50	438		public function encode($data, array $spec, $throw = false) {
51	438		$str = json_encode($data, JSON_UNESCAPED_SLASHES);
52
53	438		$first = true;
54	438		foreach ($spec as $name => $password) {
55	438		if ($name === self::STRICT) {
56			// Strict is just an option so continue.
57	1		continue;
58			}
59
60	438		$supported = $this->supportedInfo($name, $throw);
61	438		if ($supported === null) {
62	1		return null;
63			}
64
65	437		list($encode,, $method, $encodeFirst) = $supported;
66
67	437		if ($first) {
68	437		if ($encodeFirst) {
69	195		$str = static::base64urlEncode($str);
70			}
71	437		$this->pushString($str, self::EOS);
72			}
73
74		View Code Duplication	switch ($encode) {
			1 ignored issue – show Duplication introduced 2015-11-24 19:27 UTC by Report Bug Copy Issue Report This code seems to be duplicated across your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
75	437		case 'encrypt':
76	290		$str = $this->encrypt($str, $method, $password, '', $throw);
77	290		break;
78			case 'hmac':
79	292		$str = $this->hmac($str, $method, $password, 0, $throw);
80	292		break;
81			default:
82			return $this->exception($throw, "Invalid method $encode.", 500);
			0 ignored issues – show Bug Compatibility introduced 2015-11-24 19:27 UTC by Report Bug Copy Issue Report The expression `$this->exception($throw,...thod {$encode}.", 500);` of type `boolean\|null` adds the type `boolean` to the return on line 82 which is incompatible with the return type documented by `Garden\SecureString::encode` of type `string\|null`. Loading history...
83			}
84			// Return on error.
85	437		if (!$str) {
86			return null;
87			}
88
89	437		$this->pushString($str, $name);
90
91	437		$first = false;
92			}
93
94	437		return $str;
95			}
96
97			/**
98			* Decode a string that was encoded using {@link SecureString::encode()}.
99			*
100			* @param string $str The encoded string.
101			* @param array $spec An array specifying how the string should be encoded.
102			* @param bool $throw Whether or not to throw an exception on error.
103			* @return string\|null Returns the decoded string or null of there was a problem.
104			*/
105	439		public function decode($str, array $spec, $throw = false) {
106	439		$decodeFirst = false;
107	439		$wstr = $str; // wstr means working string
108	439		$used = [];
109
110	439		$strict = true;
111	439		if (array_key_exists(self::STRICT, $spec)) {
112	2		$strict = (bool)$spec[self::STRICT];
113	2		unset($spec[self::STRICT]);
114			}
115
116	439		while ($token = $this->popString($wstr)) {
117	439		if ($token === self::EOS) {
118	147		if ($decodeFirst) {
119	65		$wstr = static::base64urlDecode($wstr);
120			}
121	147		break;
122			}
123
124			try {
125	438		$supported = $this->supportedInfo($token, true);
126	3		} catch (\Exception $ex) {
127	3		return $this->exception($throw, $ex->getMessage(), 403);
			0 ignored issues – show Bug Compatibility introduced 2015-11-24 19:27 UTC by Report Bug Copy Issue Report The expression `$this->exception($throw, $ex->getMessage(), 403);` of type `boolean\|null` adds the type `boolean` to the return on line 127 which is incompatible with the return type documented by `Garden\SecureString::decode` of type `string\|null`. Loading history...
128			}
129
130	437		if (!isset($spec[$token])) {
131	144		return $this->exception($throw, "You did not provide a password for $token.", 403);
			0 ignored issues – show Bug Compatibility introduced 2015-11-24 19:27 UTC by Report Bug Copy Issue Report The expression `$this->exception($throw,...d for {$token}.", 403);` of type `boolean\|null` adds the type `boolean` to the return on line 131 which is incompatible with the return type documented by `Garden\SecureString::decode` of type `string\|null`. Loading history...
132			}
133	293		$password = $spec[$token];
134	293		array_unshift($used, $token);
135
136	293		list(, $decode, $method, $decodeFirst) = $supported;
137
138		View Code Duplication	switch ($decode) {
			1 ignored issue – show Duplication introduced 2015-11-24 19:27 UTC by Report Bug Copy Issue Report This code seems to be duplicated across your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
139	293		case 'decrypt':
140	162		$wstr = $this->decrypt($wstr, $method, $password, $throw);
141	162		break;
142			case 'verifyHmac':
143	180		$wstr = $this->verifyHmac($wstr, $method, $password, $throw);
144	180		break;
145			default:
146			return $this->exception($throw, "Invalid method $decode.", 500);
			0 ignored issues – show Bug Compatibility introduced 2015-11-24 19:27 UTC by Report Bug Copy Issue Report The expression `$this->exception($throw,...thod {$decode}.", 500);` of type `boolean\|null` adds the type `boolean` to the return on line 146 which is incompatible with the return type documented by `Garden\SecureString::decode` of type `string\|null`. Loading history...
147			}
148
149	293		if ($wstr === null) {
150	145		return null;
151			}
152			}
153
154			// Make sure that the string was secured at all.
155	147		if ($strict && array_keys($spec) != $used) {
156	1		return $this->exception($throw, 'The string is not fully secure.', 403);
			0 ignored issues – show Bug Compatibility introduced 2015-11-24 19:27 UTC by Report Bug Copy Issue Report The expression `$this->exception($throw,...t fully secure.', 403);` of type `boolean\|null` adds the type `boolean` to the return on line 156 which is incompatible with the return type documented by `Garden\SecureString::decode` of type `string\|null`. Loading history...
157			} elseif (empty($used)) {
158	1		return $this->exception($throw, 'The string is not secure.', 403);
			0 ignored issues – show Bug Compatibility introduced 2015-11-24 19:27 UTC by Report Bug Copy Issue Report The expression `$this->exception($throw,... is not secure.', 403);` of type `boolean\|null` adds the type `boolean` to the return on line 158 which is incompatible with the return type documented by `Garden\SecureString::decode` of type `string\|null`. Loading history...
159			}
160
161	146		$data = json_decode($wstr, true);
162	146		if ($data === null) {
163			return $this->exception($throw, 'The final string is not valid json.', 403);
			0 ignored issues – show Bug Compatibility introduced 2015-11-24 19:27 UTC by Report Bug Copy Issue Report The expression `$this->exception($throw,...not valid json.', 403);` of type `boolean\|null` adds the type `boolean` to the return on line 163 which is incompatible with the return type documented by `Garden\SecureString::decode` of type `string\|null`. Loading history...
164			}
165
166	146		return $data;
167			}
168
169			/**
170			* Generate a random string suitable for use as an encryption or signature key.
171			*
172			* @param int $len The number of characters in the key.
173			* @return string Returns a base64url encoded string representing the random key.
174			*/
175	2		public static function generateRandomKey($len = 32) {
176	2		$bytes = ceil($len * 3 / 4);
177
178	2		return substr(self::base64urlEncode(openssl_random_pseudo_bytes($bytes)), 0, $len);
179			}
180
181			/**
182			* Base64 Encode a string, but make it suitable to be passed in a url.
183			*
184			* @param string $str The string to encode.
185			* @return string The encoded string.
186			*/
187	437		protected static function base64urlEncode($str) {
188	437		return trim(strtr(base64_encode($str), '+/', '-_'), '=');
189			}
190
191			/**
192			* Decode a string that was encoded using base64UrlEncode().
193			*
194			* @param string $str The encoded string.
195			* @return string The decoded string.
196			*/
197	293		protected static function base64urlDecode($str) {
198	293		return base64_decode(strtr($str, '-_', '+/'));
199			}
200
201			/**
202			* Encrypt a string with {@link openssl_encrypt()}.
203			*
204			* @param string $str The string to encrypt.
205			* @param string $method The encryption cipher.
206			* @param string $password The encryption password.
207			* @param string $iv The input vector.
208			* @param bool $throw Whether or not to throw an exception on error.
209			* @return string Returns the encrypted string.
210			*/
211	290	View Code Duplication	protected function encrypt($str, $method, $password, $iv = '', $throw = false) {
			0 ignored issues – show Duplication introduced 2015-11-24 19:27 UTC by Report Bug Copy Issue Report This method seems to be duplicated in your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
212	290		if ($iv === '') {
213	290		$iv = openssl_random_pseudo_bytes(openssl_cipher_iv_length($method));
214			}
215			// Encrypt the string.
216	290		$encrypted = openssl_encrypt($str, $method, $password, OPENSSL_RAW_DATA, $iv);
217
218	290		if ($encrypted === false) {
219			return $this->exception($throw, "Error encrypting the string.", 400);
			0 ignored issues – show Bug Compatibility introduced 2015-11-24 19:27 UTC by Report Bug Copy Issue Report The expression `$this->exception($throw,...ing the string.', 400);` of type `boolean\|null` adds the type `boolean` to the return on line 219 which is incompatible with the return type documented by `Garden\SecureString::encrypt` of type `string`. Loading history...
220			}
221
222	290		$str = static::base64urlEncode($encrypted);
223	290		$this->pushString($str, static::base64urlEncode($iv));
224
225	290		return $str;
226			}
227
228			/**
229			* Decrypt a string with {@link openssl_decrypt()}.
230			*
231			* @param string $str The base64 url encoded encrypted string.
232			* @param string $method The encryption cipher.
233			* @param string $password The password to decyrpt the string.
234			* @param bool $throw Whether or not to decode the string on exception.
235			* @return string\|null Returns the decrypted string or null on error.
236			*/
237	162		protected function decrypt($str, $method, $password, $throw = false) {
238	162		$iv = static::base64urlDecode($this->popString($str));
239	162		$encrypted = static::base64urlDecode($this->popString($str));
240
241			try {
242	162		$decrypted = openssl_decrypt($encrypted, $method, $password, true, $iv);
243			} catch (\Exception $ex) {
244			return $this->exception($throw, "Error decrypting the string.", 403);
245			}
246
247	162		if ($decrypted === false) {
248	63		return $this->exception($throw, "Error decrypting the string.", 403);
249			}
250
251	99		return $decrypted;
252			}
253
254			/**
255			* Get information about a supported spec name.
256			*
257			* @param string $name The name of the spec.
258			* @param bool $throw Whether or not throw an exception on error.
259			* @return array\|null Returns an array in the form [encode, decode, method, encodeFirst].
260			* Returns null on error.
261			*/
262	439		protected function supportedInfo($name, $throw = false) {
263			switch ($name) {
264	439		case 'aes128':
265			case 'aes256':
266	291		$cipher = 'aes-'.substr($name, 3).'-cbc';
267	291		return ['encrypt', 'decrypt', $cipher, false];
268			case 'hsha1':
269	4		case 'hsha256':
270	292		$hash = substr($name, 1);
271	292		return ['hmac', 'verifyHmac', $hash, true];
272			}
273	4		return $this->exception($throw, "Spec $name not supported.", 400);
274			}
275
276			/**
277			* Sign a string with hmac and a hash method.
278			*
279			* @param string $str The string to sign.
280			* @param string $method The hash method used to sign the string.
281			* @param string $password The password used to hmac hash the string with.
282			* @param int $timestamp The timestamp used to sign the string with or 0 to use the current time.
283			* @param bool $throw Whether or not the throw an exception on error.
284			* @return string Returns the string with signing information or null on error.
285			*/
286	292	View Code Duplication	protected function hmac($str, $method, $password, $timestamp = 0, $throw = false) {
			0 ignored issues – show Duplication introduced 2015-11-24 19:27 UTC by Report Bug Copy Issue Report This method seems to be duplicated in your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
287	292		if ($timestamp === 0) {
288	292		$timestamp = time();
289			}
290			// Add the timestamp to the string.
291	292		static::pushString($str, $timestamp);
292
293			// Sign the string.
294	292		$signature = hash_hmac($method, $str, $password, true);
295	292		if ($signature === false) {
296			return $this->exception($throw, "Invalid hash method $method.", 400);
			0 ignored issues – show Bug Compatibility introduced 2015-11-24 19:27 UTC by Report Bug Copy Issue Report The expression `$this->exception($throw,...thod {$method}.", 400);` of type `boolean\|null` adds the type `boolean` to the return on line 296 which is incompatible with the return type documented by `Garden\SecureString::hmac` of type `string`. Loading history...
297			}
298
299			// Add the signature to the string.
300	292		static::pushString($str, static::base64urlEncode($signature));
301
302	292		return $str;
303			}
304
305			/**
306			* Verify the signature on a secure string.
307			*
308			* @param string $str The string to verify.
309			* @param string $method The hashing algorithm that the string was signed with.
310			* @param string $password The password used to sign the string.
311			* @param bool $throw Whether or not to throw an exeptio on error.
312			* @return bool Returns the string without the signing information or null on error.
313			*/
314	180		protected function verifyHmac($str, $method, $password, $throw = false) {
315			// Grab the signature from the string.
316	180		$signature = $this->popString($str);
317	180		if (!$signature) {
			0 ignored issues – show Bug Best Practice introduced 2015-11-24 19:27 UTC by Report Bug Copy Issue Report The expression `$signature` of type `string\|null` is loosely compared to `false`; this is ambiguous if the string can be empty. You might want to explicitly use `=== null` instead. In PHP, under loose comparison (like `==`, or `!=`, or `switch` conditions), values of different types might be equal. For `string` values, the empty string `''` is a special case, in particular the following results might be unexpected: '' == false // true '' == null // true 'ab' == false // false 'ab' == null // false // It is often better to use strict comparison '' === false // false '' === null // false Loading history...
318			return $this->exception($throw, "The signature is missing.", 403);
319			}
320	180		$signature = static::base64urlDecode($signature);
321
322			// Recalculate the signature to compare.
323	180		$calcSignature = hash_hmac($method, $str, $password, true);
324
325	180		if (strlen($signature) !== strlen($calcSignature)) {
326			return $this->exception($throw, "The signature is invalid.", 403);
327			}
328
329			// Do a double hmac comparison to prevent timing attacks.
330			// https://www.isecpartners.com/blog/2011/february/double-hmac-verification.aspx
331	180		$dblSignature = hash_hmac($method, $signature, $password, true);
332	180		$dblCalcSignature = hash_hmac($method, $calcSignature, $password, true);
333
334	180		if ($dblSignature !== $dblCalcSignature) {
335	81		return $this->exception($throw, "The signature is invalid.", 403);
336			}
337
338			// Grab the timestamp and verify it.
339	99		$timestamp = $this->popString($str);
340	99		if (!$this->verifyTimestamp($timestamp, $throw)) {
341	1		return null;
342			}
343
344	98		return $str;
345			}
346
347			/**
348			* Verify that a timestamp hasn't expired.
349			*
350			* @param string $timestamp The unix timestamp to verify.
351			* @param bool $throw Whether or not to throw an exception on error.
352			* @return bool Returns true if the timestamp is valid or false otherwise.
353			*/
354	99		protected function verifyTimestamp($timestamp, $throw = false) {
355	99		if (!is_numeric($timestamp)) {
356			return (bool)$this->exception($throw, "Invalid timestamp.", 403);
357			}
358	99		$intTimestamp = (int)$timestamp;
359	99		$now = time();
360	99		if ($intTimestamp + $this->timestampExpiry <= $now) {
361	1		return (bool)$this->exception($throw, "The timestamp has expired.", 403);
362			}
363
364	98		return true;
365			}
366
367			/**
368			* Pop a string off of the end of an encoded secure string.
369			*
370			* @param string &$str The main string to pop.
371			* @return string\|null Returns the popped string or null if {@link $str} is empty.
372			*/
373	439		protected function popString(&$str) {
374	439		if ($str === '') {
375			return null;
376			}
377
378	439		$pos = strrpos($str, '.');
379	439		if ($pos !== false) {
380	439		$result = substr($str, $pos + 1);
381	439		$str = substr($str, 0, $pos);
382			} else {
383	162		$result = $str;
384	162		$str = '';
385			}
386	439		return $result;
387			}
388
389			/**
390			* Pushes a string on to the end of an encoded secure string.
391			*
392			* @param string &$str The main string to push to.
393			* @param string\|array $item The string or array of strings to push on to the end of {@link $str}.
394			*/
395	437		protected function pushString(&$str, $item) {
396	437		if ($str) {
397	437		$str .= static::SEP;
398			}
399	437		$str .= implode(static::SEP, (array)$item);
400	437		}
401
402			/**
403			* Throw an exception or return false.
404			*
405			* @param bool $throw Whether or not to throw an exception.
406			* @param string $message The exception message.
407			* @param int $code The exception code.
408			* @return bool Returns false if {@link $throw} is false.
409			* @throws \Exception Throws an exception with {@link $message} and {@link $code}.
410			*/
411	295		protected function exception($throw, $message, $code) {
412	295		if ($throw) {
413	295		throw new \Exception($message, $code);
414			}
415	294		return null;
416			}
417
418			/**
419			* Twiddle a value in an encoded secure string to another value.
420			*
421			* This method is mainly for testing so that an invalid string can be created.
422			*
423			* @param string $string A valid cookie to twiddle.
424			* @param int $index The index of the new value.
425			* @param string $value The new value. This will be base64url encoded.
426			* @param bool $encode Whether or not to base64 url encode the value.
427			* @return string Returns the new encoded cookie.
428			*/
429	2		public function twiddle($string, $index, $value, $encode = false) {
430	2		$parts = explode(static::SEP, $string);
431
432	2		if ($encode) {
433			$value = static::base64urlEncode($value);
434			}
435	2		$parts[$index] = $value;
436
437	2		return implode(static::SEP, $parts);
438			}
439			}
440

vanilla / garden

Push — master ( b3af43...6273ca )

SecureString::encrypt() A

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