1 | <?php |
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2 | /** |
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3 | * @link https://www.yiiframework.com/ |
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4 | * @copyright Copyright (c) 2008 Yii Software LLC |
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5 | * @license https://www.yiiframework.com/license/ |
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6 | */ |
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7 | |||
8 | namespace yii\base; |
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9 | |||
10 | use yii\helpers\StringHelper; |
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11 | |||
12 | /** |
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13 | * Security provides a set of methods to handle common security-related tasks. |
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14 | * |
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15 | * In particular, Security supports the following features: |
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16 | * |
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17 | * - Encryption/decryption: [[encryptByKey()]], [[decryptByKey()]], [[encryptByPassword()]] and [[decryptByPassword()]] |
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18 | * - Key derivation using standard algorithms: [[pbkdf2()]] and [[hkdf()]] |
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19 | * - Data tampering prevention: [[hashData()]] and [[validateData()]] |
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20 | * - Password validation: [[generatePasswordHash()]] and [[validatePassword()]] |
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21 | * |
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22 | * > Note: this class requires 'OpenSSL' PHP extension for random key/string generation on Windows and |
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23 | * for encryption/decryption on all platforms. For the highest security level PHP version >= 5.5.0 is recommended. |
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24 | * |
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25 | * For more details and usage information on Security, see the [guide article on security](guide:security-overview). |
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26 | * |
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27 | * @author Qiang Xue <[email protected]> |
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28 | * @author Tom Worster <[email protected]> |
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29 | * @author Klimov Paul <[email protected]> |
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30 | * @since 2.0 |
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31 | */ |
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32 | class Security extends Component |
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33 | { |
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34 | /** |
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35 | * @var string The cipher to use for encryption and decryption. |
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36 | */ |
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37 | public $cipher = 'AES-128-CBC'; |
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38 | /** |
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39 | * @var array[] Look-up table of block sizes and key sizes for each supported OpenSSL cipher. |
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40 | * |
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41 | * In each element, the key is one of the ciphers supported by OpenSSL (@see openssl_get_cipher_methods()). |
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42 | * The value is an array of two integers, the first is the cipher's block size in bytes and the second is |
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43 | * the key size in bytes. |
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44 | * |
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45 | * > Warning: All OpenSSL ciphers that we recommend are in the default value, i.e. AES in CBC mode. |
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46 | * |
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47 | * > Note: Yii's encryption protocol uses the same size for cipher key, HMAC signature key and key |
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48 | * derivation salt. |
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49 | */ |
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50 | public $allowedCiphers = [ |
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51 | 'AES-128-CBC' => [16, 16], |
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52 | 'AES-192-CBC' => [16, 24], |
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53 | 'AES-256-CBC' => [16, 32], |
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54 | ]; |
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55 | /** |
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56 | * @var string Hash algorithm for key derivation. Recommend sha256, sha384 or sha512. |
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57 | * @see [hash_algos()](https://www.php.net/manual/en/function.hash-algos.php) |
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58 | */ |
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59 | public $kdfHash = 'sha256'; |
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60 | /** |
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61 | * @var string Hash algorithm for message authentication. Recommend sha256, sha384 or sha512. |
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62 | * @see [hash_algos()](https://www.php.net/manual/en/function.hash-algos.php) |
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63 | */ |
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64 | public $macHash = 'sha256'; |
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65 | /** |
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66 | * @var string HKDF info value for derivation of message authentication key. |
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67 | * @see hkdf() |
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68 | */ |
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69 | public $authKeyInfo = 'AuthorizationKey'; |
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70 | /** |
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71 | * @var int derivation iterations count. |
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72 | * Set as high as possible to hinder dictionary password attacks. |
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73 | */ |
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74 | public $derivationIterations = 100000; |
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75 | /** |
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76 | * @var string strategy, which should be used to generate password hash. |
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77 | * Available strategies: |
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78 | * - 'password_hash' - use of PHP `password_hash()` function with PASSWORD_DEFAULT algorithm. |
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79 | * This option is recommended, but it requires PHP version >= 5.5.0 |
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80 | * - 'crypt' - use PHP `crypt()` function. |
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81 | * @deprecated since version 2.0.7, [[generatePasswordHash()]] ignores [[passwordHashStrategy]] and |
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82 | * uses `password_hash()` when available or `crypt()` when not. |
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83 | */ |
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84 | public $passwordHashStrategy; |
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85 | /** |
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86 | * @var int Default cost used for password hashing. |
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87 | * Allowed value is between 4 and 31. |
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88 | * @see generatePasswordHash() |
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89 | * @since 2.0.6 |
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90 | */ |
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91 | public $passwordHashCost = 13; |
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92 | |||
93 | /** |
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94 | * @var boolean if LibreSSL should be used. |
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95 | * The recent (> 2.1.5) LibreSSL RNGs are faster and likely better than /dev/urandom. |
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96 | */ |
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97 | private $_useLibreSSL; |
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98 | |||
99 | |||
100 | /** |
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101 | * @return bool if LibreSSL should be used |
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102 | * Use version is 2.1.5 or higher. |
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103 | * @since 2.0.36 |
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104 | */ |
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105 | protected function shouldUseLibreSSL() |
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106 | { |
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107 | if ($this->_useLibreSSL === null) { |
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108 | // Parse OPENSSL_VERSION_TEXT because OPENSSL_VERSION_NUMBER is no use for LibreSSL. |
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109 | // https://bugs.php.net/bug.php?id=71143 |
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110 | $this->_useLibreSSL = defined('OPENSSL_VERSION_TEXT') |
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111 | && preg_match('{^LibreSSL (\d\d?)\.(\d\d?)\.(\d\d?)$}', OPENSSL_VERSION_TEXT, $matches) |
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112 | && (10000 * $matches[1]) + (100 * $matches[2]) + $matches[3] >= 20105; |
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113 | } |
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114 | |||
115 | return $this->_useLibreSSL; |
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116 | } |
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117 | |||
118 | /** |
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119 | * Encrypts data using a password. |
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120 | * Derives keys for encryption and authentication from the password using PBKDF2 and a random salt, |
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121 | * which is deliberately slow to protect against dictionary attacks. Use [[encryptByKey()]] to |
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122 | * encrypt fast using a cryptographic key rather than a password. Key derivation time is |
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123 | * determined by [[$derivationIterations]], which should be set as high as possible. |
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124 | * The encrypted data includes a keyed message authentication code (MAC) so there is no need |
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125 | * to hash input or output data. |
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126 | * > Note: Avoid encrypting with passwords wherever possible. Nothing can protect against |
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127 | * poor-quality or compromised passwords. |
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128 | * @param string $data the data to encrypt |
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129 | * @param string $password the password to use for encryption |
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130 | * @return string the encrypted data as byte string |
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131 | * @see decryptByPassword() |
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132 | * @see encryptByKey() |
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133 | */ |
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134 | 1 | public function encryptByPassword($data, $password) |
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135 | { |
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136 | 1 | return $this->encrypt($data, true, $password, null); |
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137 | } |
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138 | |||
139 | /** |
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140 | * Encrypts data using a cryptographic key. |
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141 | * Derives keys for encryption and authentication from the input key using HKDF and a random salt, |
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142 | * which is very fast relative to [[encryptByPassword()]]. The input key must be properly |
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143 | * random -- use [[generateRandomKey()]] to generate keys. |
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144 | * The encrypted data includes a keyed message authentication code (MAC) so there is no need |
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145 | * to hash input or output data. |
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146 | * @param string $data the data to encrypt |
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147 | * @param string $inputKey the input to use for encryption and authentication |
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148 | * @param string|null $info optional context and application specific information, see [[hkdf()]] |
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149 | * @return string the encrypted data as byte string |
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150 | * @see decryptByKey() |
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151 | * @see encryptByPassword() |
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152 | */ |
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153 | 1 | public function encryptByKey($data, $inputKey, $info = null) |
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154 | { |
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155 | 1 | return $this->encrypt($data, false, $inputKey, $info); |
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156 | } |
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157 | |||
158 | /** |
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159 | * Verifies and decrypts data encrypted with [[encryptByPassword()]]. |
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160 | * @param string $data the encrypted data to decrypt |
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161 | * @param string $password the password to use for decryption |
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162 | * @return bool|string the decrypted data or false on authentication failure |
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163 | * @see encryptByPassword() |
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164 | */ |
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165 | 10 | public function decryptByPassword($data, $password) |
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166 | { |
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167 | 10 | return $this->decrypt($data, true, $password, null); |
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168 | } |
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169 | |||
170 | /** |
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171 | * Verifies and decrypts data encrypted with [[encryptByKey()]]. |
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172 | * @param string $data the encrypted data to decrypt |
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173 | * @param string $inputKey the input to use for encryption and authentication |
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174 | * @param string|null $info optional context and application specific information, see [[hkdf()]] |
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175 | * @return bool|string the decrypted data or false on authentication failure |
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176 | * @see encryptByKey() |
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177 | */ |
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178 | 10 | public function decryptByKey($data, $inputKey, $info = null) |
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179 | { |
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180 | 10 | return $this->decrypt($data, false, $inputKey, $info); |
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181 | } |
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182 | |||
183 | /** |
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184 | * Encrypts data. |
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185 | * |
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186 | * @param string $data data to be encrypted |
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187 | * @param bool $passwordBased set true to use password-based key derivation |
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188 | * @param string $secret the encryption password or key |
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189 | * @param string|null $info context/application specific information, e.g. a user ID |
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190 | * See [RFC 5869 Section 3.2](https://tools.ietf.org/html/rfc5869#section-3.2) for more details. |
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191 | * |
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192 | * @return string the encrypted data as byte string |
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193 | * @throws InvalidConfigException on OpenSSL not loaded |
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194 | * @throws Exception on OpenSSL error |
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195 | * @see decrypt() |
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196 | */ |
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197 | 2 | protected function encrypt($data, $passwordBased, $secret, $info) |
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198 | { |
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199 | 2 | if (!extension_loaded('openssl')) { |
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200 | throw new InvalidConfigException('Encryption requires the OpenSSL PHP extension'); |
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201 | } |
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202 | 2 | if (!isset($this->allowedCiphers[$this->cipher][0], $this->allowedCiphers[$this->cipher][1])) { |
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203 | throw new InvalidConfigException($this->cipher . ' is not an allowed cipher'); |
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204 | } |
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205 | |||
206 | 2 | list($blockSize, $keySize) = $this->allowedCiphers[$this->cipher]; |
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207 | |||
208 | 2 | $keySalt = $this->generateRandomKey($keySize); |
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209 | 2 | if ($passwordBased) { |
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210 | 1 | $key = $this->pbkdf2($this->kdfHash, $secret, $keySalt, $this->derivationIterations, $keySize); |
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211 | } else { |
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212 | 1 | $key = $this->hkdf($this->kdfHash, $secret, $keySalt, $info, $keySize); |
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213 | } |
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214 | |||
215 | 2 | $iv = $this->generateRandomKey($blockSize); |
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216 | |||
217 | 2 | $encrypted = openssl_encrypt($data, $this->cipher, $key, OPENSSL_RAW_DATA, $iv); |
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218 | 2 | if ($encrypted === false) { |
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219 | throw new \yii\base\Exception('OpenSSL failure on encryption: ' . openssl_error_string()); |
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220 | } |
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221 | |||
222 | 2 | $authKey = $this->hkdf($this->kdfHash, $key, null, $this->authKeyInfo, $keySize); |
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223 | 2 | $hashed = $this->hashData($iv . $encrypted, $authKey); |
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224 | |||
225 | /* |
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226 | * Output: [keySalt][MAC][IV][ciphertext] |
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227 | * - keySalt is KEY_SIZE bytes long |
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228 | * - MAC: message authentication code, length same as the output of MAC_HASH |
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229 | * - IV: initialization vector, length $blockSize |
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230 | */ |
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231 | 2 | return $keySalt . $hashed; |
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232 | } |
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233 | |||
234 | /** |
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235 | * Decrypts data. |
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236 | * |
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237 | * @param string $data encrypted data to be decrypted. |
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238 | * @param bool $passwordBased set true to use password-based key derivation |
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239 | * @param string $secret the decryption password or key |
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240 | * @param string|null $info context/application specific information, @see encrypt() |
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241 | * |
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242 | * @return bool|string the decrypted data or false on authentication failure |
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243 | * @throws InvalidConfigException on OpenSSL not loaded |
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244 | * @throws Exception on OpenSSL error |
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245 | * @see encrypt() |
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246 | */ |
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247 | 20 | protected function decrypt($data, $passwordBased, $secret, $info) |
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248 | { |
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249 | 20 | if (!extension_loaded('openssl')) { |
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250 | throw new InvalidConfigException('Encryption requires the OpenSSL PHP extension'); |
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251 | } |
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252 | 20 | if (!isset($this->allowedCiphers[$this->cipher][0], $this->allowedCiphers[$this->cipher][1])) { |
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253 | throw new InvalidConfigException($this->cipher . ' is not an allowed cipher'); |
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254 | } |
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255 | |||
256 | 20 | list($blockSize, $keySize) = $this->allowedCiphers[$this->cipher]; |
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257 | |||
258 | 20 | $keySalt = StringHelper::byteSubstr($data, 0, $keySize); |
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259 | 20 | if ($passwordBased) { |
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260 | 10 | $key = $this->pbkdf2($this->kdfHash, $secret, $keySalt, $this->derivationIterations, $keySize); |
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261 | } else { |
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262 | 10 | $key = $this->hkdf($this->kdfHash, $secret, $keySalt, $info, $keySize); |
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263 | } |
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264 | |||
265 | 20 | $authKey = $this->hkdf($this->kdfHash, $key, null, $this->authKeyInfo, $keySize); |
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266 | 20 | $data = $this->validateData(StringHelper::byteSubstr($data, $keySize, null), $authKey); |
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267 | 20 | if ($data === false) { |
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268 | 2 | return false; |
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269 | } |
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270 | |||
271 | 20 | $iv = StringHelper::byteSubstr($data, 0, $blockSize); |
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272 | 20 | $encrypted = StringHelper::byteSubstr($data, $blockSize, null); |
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273 | |||
274 | 20 | $decrypted = openssl_decrypt($encrypted, $this->cipher, $key, OPENSSL_RAW_DATA, $iv); |
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275 | 20 | if ($decrypted === false) { |
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276 | throw new \yii\base\Exception('OpenSSL failure on decryption: ' . openssl_error_string()); |
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277 | } |
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278 | |||
279 | 20 | return $decrypted; |
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280 | } |
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281 | |||
282 | /** |
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283 | * Derives a key from the given input key using the standard HKDF algorithm. |
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284 | * Implements HKDF specified in [RFC 5869](https://tools.ietf.org/html/rfc5869). |
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285 | * Recommend use one of the SHA-2 hash algorithms: sha224, sha256, sha384 or sha512. |
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286 | * @param string $algo a hash algorithm supported by `hash_hmac()`, e.g. 'SHA-256' |
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287 | * @param string $inputKey the source key |
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288 | * @param string|null $salt the random salt |
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289 | * @param string|null $info optional info to bind the derived key material to application- |
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290 | * and context-specific information, e.g. a user ID or API version, see |
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291 | * [RFC 5869](https://tools.ietf.org/html/rfc5869) |
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292 | * @param int $length length of the output key in bytes. If 0, the output key is |
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293 | * the length of the hash algorithm output. |
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294 | * @throws InvalidArgumentException when HMAC generation fails. |
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295 | * @return string the derived key |
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296 | */ |
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297 | 27 | public function hkdf($algo, $inputKey, $salt = null, $info = null, $length = 0) |
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298 | { |
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299 | 27 | if (function_exists('hash_hkdf')) { |
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300 | 27 | $outputKey = hash_hkdf((string)$algo, (string)$inputKey, $length, (string)$info, (string)$salt); |
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301 | 27 | if ($outputKey === false) { |
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302 | throw new InvalidArgumentException('Invalid parameters to hash_hkdf()'); |
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303 | } |
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304 | |||
305 | 27 | return $outputKey; |
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306 | } |
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307 | |||
308 | $test = @hash_hmac($algo, '', '', true); |
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309 | if (!$test) { |
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310 | throw new InvalidArgumentException('Failed to generate HMAC with hash algorithm: ' . $algo); |
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311 | } |
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312 | $hashLength = StringHelper::byteLength($test); |
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313 | if (is_string($length) && preg_match('{^\d{1,16}$}', $length)) { |
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314 | $length = (int) $length; |
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315 | } |
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316 | if (!is_int($length) || $length < 0 || $length > 255 * $hashLength) { |
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317 | throw new InvalidArgumentException('Invalid length'); |
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318 | } |
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319 | $blocks = $length !== 0 ? ceil($length / $hashLength) : 1; |
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320 | |||
321 | if ($salt === null) { |
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322 | $salt = str_repeat("\0", $hashLength); |
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323 | } |
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324 | $prKey = hash_hmac($algo, $inputKey, $salt, true); |
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325 | |||
326 | $hmac = ''; |
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327 | $outputKey = ''; |
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328 | for ($i = 1; $i <= $blocks; $i++) { |
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329 | $hmac = hash_hmac($algo, $hmac . $info . chr($i), $prKey, true); |
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330 | $outputKey .= $hmac; |
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331 | } |
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332 | |||
333 | if ($length !== 0) { |
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334 | $outputKey = StringHelper::byteSubstr($outputKey, 0, $length); |
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335 | } |
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336 | |||
337 | return $outputKey; |
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338 | } |
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339 | |||
340 | /** |
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341 | * Derives a key from the given password using the standard PBKDF2 algorithm. |
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342 | * Implements HKDF2 specified in [RFC 2898](https://datatracker.ietf.org/doc/html/rfc2898#section-5.2) |
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343 | * Recommend use one of the SHA-2 hash algorithms: sha224, sha256, sha384 or sha512. |
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344 | * @param string $algo a hash algorithm supported by `hash_hmac()`, e.g. 'SHA-256' |
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345 | * @param string $password the source password |
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346 | * @param string $salt the random salt |
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347 | * @param int $iterations the number of iterations of the hash algorithm. Set as high as |
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348 | * possible to hinder dictionary password attacks. |
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349 | * @param int $length length of the output key in bytes. If 0, the output key is |
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350 | * the length of the hash algorithm output. |
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351 | * @return string the derived key |
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352 | * @throws InvalidArgumentException when hash generation fails due to invalid params given. |
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353 | */ |
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354 | 18 | public function pbkdf2($algo, $password, $salt, $iterations, $length = 0) |
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355 | { |
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356 | 18 | if (function_exists('hash_pbkdf2') && PHP_VERSION_ID >= 50500) { |
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357 | 18 | $outputKey = hash_pbkdf2($algo, $password, $salt, $iterations, $length, true); |
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358 | 18 | if ($outputKey === false) { |
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359 | throw new InvalidArgumentException('Invalid parameters to hash_pbkdf2()'); |
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360 | } |
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361 | |||
362 | 18 | return $outputKey; |
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363 | } |
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364 | |||
365 | // todo: is there a nice way to reduce the code repetition in hkdf() and pbkdf2()? |
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366 | $test = @hash_hmac($algo, '', '', true); |
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367 | if (!$test) { |
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368 | throw new InvalidArgumentException('Failed to generate HMAC with hash algorithm: ' . $algo); |
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369 | } |
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370 | if (is_string($iterations) && preg_match('{^\d{1,16}$}', $iterations)) { |
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371 | $iterations = (int) $iterations; |
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372 | } |
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373 | if (!is_int($iterations) || $iterations < 1) { |
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374 | throw new InvalidArgumentException('Invalid iterations'); |
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375 | } |
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376 | if (is_string($length) && preg_match('{^\d{1,16}$}', $length)) { |
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377 | $length = (int) $length; |
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378 | } |
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379 | if (!is_int($length) || $length < 0) { |
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380 | throw new InvalidArgumentException('Invalid length'); |
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381 | } |
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382 | $hashLength = StringHelper::byteLength($test); |
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383 | $blocks = $length !== 0 ? ceil($length / $hashLength) : 1; |
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384 | |||
385 | $outputKey = ''; |
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386 | for ($j = 1; $j <= $blocks; $j++) { |
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387 | $hmac = hash_hmac($algo, $salt . pack('N', $j), $password, true); |
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388 | $xorsum = $hmac; |
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389 | for ($i = 1; $i < $iterations; $i++) { |
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390 | $hmac = hash_hmac($algo, $hmac, $password, true); |
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391 | $xorsum ^= $hmac; |
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392 | } |
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393 | $outputKey .= $xorsum; |
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394 | } |
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395 | |||
396 | if ($length !== 0) { |
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397 | $outputKey = StringHelper::byteSubstr($outputKey, 0, $length); |
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398 | } |
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399 | |||
400 | return $outputKey; |
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401 | } |
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402 | |||
403 | /** |
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404 | * Prefixes data with a keyed hash value so that it can later be detected if it is tampered. |
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405 | * There is no need to hash inputs or outputs of [[encryptByKey()]] or [[encryptByPassword()]] |
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406 | * as those methods perform the task. |
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407 | * @param string $data the data to be protected |
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408 | * @param string $key the secret key to be used for generating hash. Should be a secure |
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409 | * cryptographic key. |
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410 | * @param bool $rawHash whether the generated hash value is in raw binary format. If false, lowercase |
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411 | * hex digits will be generated. |
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412 | * @return string the data prefixed with the keyed hash |
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413 | * @throws InvalidConfigException when HMAC generation fails. |
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414 | * @see validateData() |
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415 | * @see generateRandomKey() |
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416 | * @see hkdf() |
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417 | * @see pbkdf2() |
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418 | */ |
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419 | 12 | public function hashData($data, $key, $rawHash = false) |
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420 | { |
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421 | 12 | $hash = hash_hmac($this->macHash, $data, $key, $rawHash); |
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422 | 12 | if (!$hash) { |
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423 | throw new InvalidConfigException('Failed to generate HMAC with hash algorithm: ' . $this->macHash); |
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424 | } |
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425 | |||
426 | 12 | return $hash . $data; |
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427 | } |
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428 | |||
429 | /** |
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430 | * Validates if the given data is tampered. |
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431 | * @param string $data the data to be validated. The data must be previously |
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432 | * generated by [[hashData()]]. |
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433 | * @param string $key the secret key that was previously used to generate the hash for the data in [[hashData()]]. |
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434 | * function to see the supported hashing algorithms on your system. This must be the same |
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435 | * as the value passed to [[hashData()]] when generating the hash for the data. |
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436 | * @param bool $rawHash this should take the same value as when you generate the data using [[hashData()]]. |
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437 | * It indicates whether the hash value in the data is in binary format. If false, it means the hash value consists |
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438 | * of lowercase hex digits only. |
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439 | * hex digits will be generated. |
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440 | * @return string|false the real data with the hash stripped off. False if the data is tampered. |
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441 | * @throws InvalidConfigException when HMAC generation fails. |
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442 | * @see hashData() |
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443 | */ |
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444 | 21 | public function validateData($data, $key, $rawHash = false) |
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445 | { |
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446 | 21 | $test = @hash_hmac($this->macHash, '', '', $rawHash); |
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447 | 21 | if (!$test) { |
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448 | throw new InvalidConfigException('Failed to generate HMAC with hash algorithm: ' . $this->macHash); |
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449 | } |
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450 | 21 | $hashLength = StringHelper::byteLength($test); |
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451 | 21 | if (StringHelper::byteLength($data) >= $hashLength) { |
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452 | 21 | $hash = StringHelper::byteSubstr($data, 0, $hashLength); |
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453 | 21 | $pureData = StringHelper::byteSubstr($data, $hashLength, null); |
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454 | |||
455 | 21 | $calculatedHash = hash_hmac($this->macHash, $pureData, $key, $rawHash); |
|
456 | |||
457 | 21 | if ($this->compareString($hash, $calculatedHash)) { |
|
458 | 21 | return $pureData; |
|
459 | } |
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460 | } |
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461 | |||
462 | 3 | return false; |
|
463 | } |
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464 | |||
465 | /** |
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466 | * Generates specified number of random bytes. |
||
467 | * Note that output may not be ASCII. |
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468 | * @see generateRandomString() if you need a string. |
||
469 | * |
||
470 | * @param int $length the number of bytes to generate |
||
471 | * @return string the generated random bytes |
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472 | * @throws InvalidArgumentException if wrong length is specified |
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473 | * @throws Exception on failure. |
||
474 | */ |
||
475 | 117 | public function generateRandomKey($length = 32) |
|
476 | { |
||
477 | 117 | if (!is_int($length)) { |
|
478 | 3 | throw new InvalidArgumentException('First parameter ($length) must be an integer'); |
|
479 | } |
||
480 | |||
481 | 114 | if ($length < 1) { |
|
482 | 3 | throw new InvalidArgumentException('First parameter ($length) must be greater than 0'); |
|
483 | } |
||
484 | |||
485 | 111 | return random_bytes($length); |
|
486 | } |
||
487 | |||
488 | /** |
||
489 | * Generates a random string of specified length. |
||
490 | * The string generated matches [A-Za-z0-9_-]+ and is transparent to URL-encoding. |
||
491 | * |
||
492 | * @param int $length the length of the key in characters |
||
493 | * @return string the generated random key |
||
494 | * @throws Exception on failure. |
||
495 | */ |
||
496 | 101 | public function generateRandomString($length = 32) |
|
497 | { |
||
498 | 101 | if (!is_int($length)) { |
|
499 | throw new InvalidArgumentException('First parameter ($length) must be an integer'); |
||
500 | } |
||
501 | |||
502 | 101 | if ($length < 1) { |
|
503 | throw new InvalidArgumentException('First parameter ($length) must be greater than 0'); |
||
504 | } |
||
505 | |||
506 | 101 | $bytes = $this->generateRandomKey($length); |
|
507 | 101 | return substr(StringHelper::base64UrlEncode($bytes), 0, $length); |
|
508 | } |
||
509 | |||
510 | /** |
||
511 | * Generates a secure hash from a password and a random salt. |
||
512 | * |
||
513 | * The generated hash can be stored in database. |
||
514 | * Later when a password needs to be validated, the hash can be fetched and passed |
||
515 | * to [[validatePassword()]]. For example, |
||
516 | * |
||
517 | * ```php |
||
518 | * // generates the hash (usually done during user registration or when the password is changed) |
||
519 | * $hash = Yii::$app->getSecurity()->generatePasswordHash($password); |
||
520 | * // ...save $hash in database... |
||
521 | * |
||
522 | * // during login, validate if the password entered is correct using $hash fetched from database |
||
523 | * if (Yii::$app->getSecurity()->validatePassword($password, $hash)) { |
||
524 | * // password is good |
||
525 | * } else { |
||
526 | * // password is bad |
||
527 | * } |
||
528 | * ``` |
||
529 | * |
||
530 | * @param string $password The password to be hashed. |
||
531 | * @param int|null $cost Cost parameter used by the Blowfish hash algorithm. |
||
532 | * The higher the value of cost, |
||
533 | * the longer it takes to generate the hash and to verify a password against it. Higher cost |
||
534 | * therefore slows down a brute-force attack. For best protection against brute-force attacks, |
||
535 | * set it to the highest value that is tolerable on production servers. The time taken to |
||
536 | * compute the hash doubles for every increment by one of $cost. |
||
537 | * @return string The password hash string. When [[passwordHashStrategy]] is set to 'crypt', |
||
538 | * the output is always 60 ASCII characters, when set to 'password_hash' the output length |
||
539 | * might increase in future versions of PHP (https://www.php.net/manual/en/function.password-hash.php) |
||
540 | * @throws Exception on bad password parameter or cost parameter. |
||
541 | * @see validatePassword() |
||
542 | */ |
||
543 | 1 | public function generatePasswordHash($password, $cost = null) |
|
544 | { |
||
545 | 1 | if ($cost === null) { |
|
546 | 1 | $cost = $this->passwordHashCost; |
|
547 | } |
||
548 | |||
549 | 1 | if (function_exists('password_hash')) { |
|
550 | /* @noinspection PhpUndefinedConstantInspection */ |
||
551 | 1 | return password_hash($password, PASSWORD_DEFAULT, ['cost' => $cost]); |
|
552 | } |
||
553 | |||
554 | $salt = $this->generateSalt($cost); |
||
555 | $hash = crypt($password, $salt); |
||
556 | // strlen() is safe since crypt() returns only ascii |
||
557 | if (!is_string($hash) || strlen($hash) !== 60) { |
||
558 | throw new Exception('Unknown error occurred while generating hash.'); |
||
559 | } |
||
560 | |||
561 | return $hash; |
||
562 | } |
||
563 | |||
564 | /** |
||
565 | * Verifies a password against a hash. |
||
566 | * @param string $password The password to verify. |
||
567 | * @param string $hash The hash to verify the password against. |
||
568 | * @return bool whether the password is correct. |
||
569 | * @throws InvalidArgumentException on bad password/hash parameters or if crypt() with Blowfish hash is not available. |
||
570 | * @see generatePasswordHash() |
||
571 | */ |
||
572 | 1 | public function validatePassword($password, $hash) |
|
573 | { |
||
574 | 1 | if (!is_string($password) || $password === '') { |
|
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|||
575 | throw new InvalidArgumentException('Password must be a string and cannot be empty.'); |
||
576 | } |
||
577 | |||
578 | if ( |
||
579 | 1 | !preg_match('/^\$2[axy]\$(\d\d)\$[\.\/0-9A-Za-z]{22}/', $hash, $matches) |
|
580 | 1 | || $matches[1] < 4 |
|
581 | 1 | || $matches[1] > 30 |
|
582 | ) { |
||
583 | throw new InvalidArgumentException('Hash is invalid.'); |
||
584 | } |
||
585 | |||
586 | 1 | if (function_exists('password_verify')) { |
|
587 | 1 | return password_verify($password, $hash); |
|
588 | } |
||
589 | |||
590 | $test = crypt($password, $hash); |
||
591 | $n = strlen($test); |
||
592 | if ($n !== 60) { |
||
593 | return false; |
||
594 | } |
||
595 | |||
596 | return $this->compareString($test, $hash); |
||
597 | } |
||
598 | |||
599 | /** |
||
600 | * Generates a salt that can be used to generate a password hash. |
||
601 | * |
||
602 | * The PHP [crypt()](https://www.php.net/manual/en/function.crypt.php) built-in function |
||
603 | * requires, for the Blowfish hash algorithm, a salt string in a specific format: |
||
604 | * "$2a$", "$2x$" or "$2y$", a two digit cost parameter, "$", and 22 characters |
||
605 | * from the alphabet "./0-9A-Za-z". |
||
606 | * |
||
607 | * @param int $cost the cost parameter |
||
608 | * @return string the random salt value. |
||
609 | * @throws InvalidArgumentException if the cost parameter is out of the range of 4 to 31. |
||
610 | */ |
||
611 | protected function generateSalt($cost = 13) |
||
612 | { |
||
613 | $cost = (int) $cost; |
||
614 | if ($cost < 4 || $cost > 31) { |
||
615 | throw new InvalidArgumentException('Cost must be between 4 and 31.'); |
||
616 | } |
||
617 | |||
618 | // Get a 20-byte random string |
||
619 | $rand = $this->generateRandomKey(20); |
||
620 | // Form the prefix that specifies Blowfish (bcrypt) algorithm and cost parameter. |
||
621 | $salt = sprintf('$2y$%02d$', $cost); |
||
622 | // Append the random salt data in the required base64 format. |
||
623 | $salt .= str_replace('+', '.', substr(base64_encode($rand), 0, 22)); |
||
624 | |||
625 | return $salt; |
||
626 | } |
||
627 | |||
628 | /** |
||
629 | * Performs string comparison using timing attack resistant approach. |
||
630 | * @see https://codereview.stackexchange.com/q/13512 |
||
631 | * @param string $expected string to compare. |
||
632 | * @param string $actual user-supplied string. |
||
633 | * @return bool whether strings are equal. |
||
634 | */ |
||
635 | 39 | public function compareString($expected, $actual) |
|
636 | { |
||
637 | 39 | if (!is_string($expected)) { |
|
638 | throw new InvalidArgumentException('Expected expected value to be a string, ' . gettype($expected) . ' given.'); |
||
639 | } |
||
640 | |||
641 | 39 | if (!is_string($actual)) { |
|
642 | throw new InvalidArgumentException('Expected actual value to be a string, ' . gettype($actual) . ' given.'); |
||
643 | } |
||
644 | |||
645 | 39 | if (function_exists('hash_equals')) { |
|
646 | 39 | return hash_equals($expected, $actual); |
|
647 | } |
||
648 | |||
649 | $expected .= "\0"; |
||
650 | $actual .= "\0"; |
||
651 | $expectedLength = StringHelper::byteLength($expected); |
||
652 | $actualLength = StringHelper::byteLength($actual); |
||
653 | $diff = $expectedLength - $actualLength; |
||
654 | for ($i = 0; $i < $actualLength; $i++) { |
||
655 | $diff |= (ord($actual[$i]) ^ ord($expected[$i % $expectedLength])); |
||
656 | } |
||
657 | |||
658 | return $diff === 0; |
||
659 | } |
||
660 | |||
661 | /** |
||
662 | * Masks a token to make it uncompressible. |
||
663 | * Applies a random mask to the token and prepends the mask used to the result making the string always unique. |
||
664 | * Used to mitigate BREACH attack by randomizing how token is outputted on each request. |
||
665 | * @param string $token An unmasked token. |
||
666 | * @return string A masked token. |
||
667 | * @since 2.0.12 |
||
668 | */ |
||
669 | 93 | public function maskToken($token) |
|
670 | { |
||
671 | // The number of bytes in a mask is always equal to the number of bytes in a token. |
||
672 | 93 | $mask = $this->generateRandomKey(StringHelper::byteLength($token)); |
|
673 | 92 | return StringHelper::base64UrlEncode($mask . ($mask ^ $token)); |
|
674 | } |
||
675 | |||
676 | /** |
||
677 | * Unmasks a token previously masked by `maskToken`. |
||
678 | * @param string $maskedToken A masked token. |
||
679 | * @return string An unmasked token, or an empty string in case of token format is invalid. |
||
680 | * @since 2.0.12 |
||
681 | */ |
||
682 | 9 | public function unmaskToken($maskedToken) |
|
683 | { |
||
684 | 9 | $decoded = StringHelper::base64UrlDecode($maskedToken); |
|
685 | 9 | $length = StringHelper::byteLength($decoded) / 2; |
|
686 | // Check if the masked token has an even length. |
||
687 | 9 | if (!is_int($length)) { |
|
688 | 1 | return ''; |
|
689 | } |
||
690 | |||
691 | 9 | return StringHelper::byteSubstr($decoded, $length, $length) ^ StringHelper::byteSubstr($decoded, 0, $length); |
|
692 | } |
||
693 | } |
||
694 |