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Rev | Author | Line No. | Line |
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597 | daniel-mar | 1 | <?php |
2 | |||
3 | namespace Firebase\JWT; |
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4 | |||
679 | daniel-mar | 5 | use ArrayAccess; |
618 | daniel-mar | 6 | use DomainException; |
637 | daniel-mar | 7 | use Exception; |
618 | daniel-mar | 8 | use InvalidArgumentException; |
679 | daniel-mar | 9 | use OpenSSLAsymmetricKey; |
618 | daniel-mar | 10 | use UnexpectedValueException; |
11 | use DateTime; |
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597 | daniel-mar | 12 | |
13 | /** |
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14 | * JSON Web Token implementation, based on this spec: |
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15 | * https://tools.ietf.org/html/rfc7519 |
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16 | * |
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17 | * PHP version 5 |
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18 | * |
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19 | * @category Authentication |
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20 | * @package Authentication_JWT |
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21 | * @author Neuman Vong <neuman@twilio.com> |
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22 | * @author Anant Narayanan <anant@php.net> |
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23 | * @license http://opensource.org/licenses/BSD-3-Clause 3-clause BSD |
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24 | * @link https://github.com/firebase/php-jwt |
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25 | */ |
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26 | class JWT |
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27 | { |
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28 | const ASN1_INTEGER = 0x02; |
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29 | const ASN1_SEQUENCE = 0x10; |
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30 | const ASN1_BIT_STRING = 0x03; |
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31 | |||
32 | /** |
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33 | * When checking nbf, iat or expiration times, |
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34 | * we want to provide some extra leeway time to |
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35 | * account for clock skew. |
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36 | */ |
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37 | public static $leeway = 0; |
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38 | |||
39 | /** |
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40 | * Allow the current timestamp to be specified. |
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41 | * Useful for fixing a value within unit testing. |
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42 | * |
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43 | * Will default to PHP time() value if null. |
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44 | */ |
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45 | public static $timestamp = null; |
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46 | |||
47 | public static $supported_algs = array( |
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618 | daniel-mar | 48 | 'ES384' => array('openssl', 'SHA384'), |
597 | daniel-mar | 49 | 'ES256' => array('openssl', 'SHA256'), |
50 | 'HS256' => array('hash_hmac', 'SHA256'), |
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51 | 'HS384' => array('hash_hmac', 'SHA384'), |
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52 | 'HS512' => array('hash_hmac', 'SHA512'), |
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53 | 'RS256' => array('openssl', 'SHA256'), |
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54 | 'RS384' => array('openssl', 'SHA384'), |
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55 | 'RS512' => array('openssl', 'SHA512'), |
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637 | daniel-mar | 56 | 'EdDSA' => array('sodium_crypto', 'EdDSA'), |
597 | daniel-mar | 57 | ); |
58 | |||
59 | /** |
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60 | * Decodes a JWT string into a PHP object. |
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61 | * |
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62 | * @param string $jwt The JWT |
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679 | daniel-mar | 63 | * @param Key|array<Key>|mixed $keyOrKeyArray The Key or array of Key objects. |
597 | daniel-mar | 64 | * If the algorithm used is asymmetric, this is the public key |
679 | daniel-mar | 65 | * Each Key object contains an algorithm and matching key. |
618 | daniel-mar | 66 | * Supported algorithms are 'ES384','ES256', 'HS256', 'HS384', |
67 | * 'HS512', 'RS256', 'RS384', and 'RS512' |
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679 | daniel-mar | 68 | * @param array $allowed_algs [DEPRECATED] List of supported verification algorithms. Only |
69 | * should be used for backwards compatibility. |
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597 | daniel-mar | 70 | * |
71 | * @return object The JWT's payload as a PHP object |
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72 | * |
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618 | daniel-mar | 73 | * @throws InvalidArgumentException Provided JWT was empty |
597 | daniel-mar | 74 | * @throws UnexpectedValueException Provided JWT was invalid |
75 | * @throws SignatureInvalidException Provided JWT was invalid because the signature verification failed |
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76 | * @throws BeforeValidException Provided JWT is trying to be used before it's eligible as defined by 'nbf' |
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77 | * @throws BeforeValidException Provided JWT is trying to be used before it's been created as defined by 'iat' |
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78 | * @throws ExpiredException Provided JWT has since expired, as defined by the 'exp' claim |
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79 | * |
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80 | * @uses jsonDecode |
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81 | * @uses urlsafeB64Decode |
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82 | */ |
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679 | daniel-mar | 83 | public static function decode($jwt, $keyOrKeyArray, array $allowed_algs = array()) |
597 | daniel-mar | 84 | { |
85 | $timestamp = \is_null(static::$timestamp) ? \time() : static::$timestamp; |
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86 | |||
679 | daniel-mar | 87 | if (empty($keyOrKeyArray)) { |
597 | daniel-mar | 88 | throw new InvalidArgumentException('Key may not be empty'); |
89 | } |
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90 | $tks = \explode('.', $jwt); |
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91 | if (\count($tks) != 3) { |
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92 | throw new UnexpectedValueException('Wrong number of segments'); |
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93 | } |
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94 | list($headb64, $bodyb64, $cryptob64) = $tks; |
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95 | if (null === ($header = static::jsonDecode(static::urlsafeB64Decode($headb64)))) { |
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96 | throw new UnexpectedValueException('Invalid header encoding'); |
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97 | } |
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98 | if (null === $payload = static::jsonDecode(static::urlsafeB64Decode($bodyb64))) { |
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99 | throw new UnexpectedValueException('Invalid claims encoding'); |
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100 | } |
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101 | if (false === ($sig = static::urlsafeB64Decode($cryptob64))) { |
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102 | throw new UnexpectedValueException('Invalid signature encoding'); |
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103 | } |
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104 | if (empty($header->alg)) { |
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105 | throw new UnexpectedValueException('Empty algorithm'); |
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106 | } |
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107 | if (empty(static::$supported_algs[$header->alg])) { |
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108 | throw new UnexpectedValueException('Algorithm not supported'); |
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109 | } |
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679 | daniel-mar | 110 | |
111 | list($keyMaterial, $algorithm) = self::getKeyMaterialAndAlgorithm( |
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112 | $keyOrKeyArray, |
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113 | empty($header->kid) ? null : $header->kid |
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114 | ); |
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115 | |||
116 | if (empty($algorithm)) { |
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117 | // Use deprecated "allowed_algs" to determine if the algorithm is supported. |
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118 | // This opens up the possibility of an attack in some implementations. |
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119 | // @see https://github.com/firebase/php-jwt/issues/351 |
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120 | if (!\in_array($header->alg, $allowed_algs)) { |
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121 | throw new UnexpectedValueException('Algorithm not allowed'); |
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122 | } |
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123 | } else { |
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124 | // Check the algorithm |
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125 | if (!self::constantTimeEquals($algorithm, $header->alg)) { |
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126 | // See issue #351 |
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127 | throw new UnexpectedValueException('Incorrect key for this algorithm'); |
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128 | } |
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597 | daniel-mar | 129 | } |
618 | daniel-mar | 130 | if ($header->alg === 'ES256' || $header->alg === 'ES384') { |
131 | // OpenSSL expects an ASN.1 DER sequence for ES256/ES384 signatures |
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597 | daniel-mar | 132 | $sig = self::signatureToDER($sig); |
133 | } |
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134 | |||
679 | daniel-mar | 135 | if (!static::verify("$headb64.$bodyb64", $sig, $keyMaterial, $header->alg)) { |
597 | daniel-mar | 136 | throw new SignatureInvalidException('Signature verification failed'); |
137 | } |
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138 | |||
139 | // Check the nbf if it is defined. This is the time that the |
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140 | // token can actually be used. If it's not yet that time, abort. |
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141 | if (isset($payload->nbf) && $payload->nbf > ($timestamp + static::$leeway)) { |
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142 | throw new BeforeValidException( |
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143 | 'Cannot handle token prior to ' . \date(DateTime::ISO8601, $payload->nbf) |
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144 | ); |
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145 | } |
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146 | |||
147 | // Check that this token has been created before 'now'. This prevents |
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148 | // using tokens that have been created for later use (and haven't |
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149 | // correctly used the nbf claim). |
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150 | if (isset($payload->iat) && $payload->iat > ($timestamp + static::$leeway)) { |
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151 | throw new BeforeValidException( |
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152 | 'Cannot handle token prior to ' . \date(DateTime::ISO8601, $payload->iat) |
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153 | ); |
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154 | } |
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155 | |||
156 | // Check if this token has expired. |
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157 | if (isset($payload->exp) && ($timestamp - static::$leeway) >= $payload->exp) { |
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158 | throw new ExpiredException('Expired token'); |
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159 | } |
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160 | |||
161 | return $payload; |
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162 | } |
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163 | |||
164 | /** |
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165 | * Converts and signs a PHP object or array into a JWT string. |
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166 | * |
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618 | daniel-mar | 167 | * @param object|array $payload PHP object or array |
168 | * @param string|resource $key The secret key. |
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169 | * If the algorithm used is asymmetric, this is the private key |
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170 | * @param string $alg The signing algorithm. |
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171 | * Supported algorithms are 'ES384','ES256', 'HS256', 'HS384', |
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172 | * 'HS512', 'RS256', 'RS384', and 'RS512' |
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173 | * @param mixed $keyId |
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174 | * @param array $head An array with header elements to attach |
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597 | daniel-mar | 175 | * |
176 | * @return string A signed JWT |
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177 | * |
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178 | * @uses jsonEncode |
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179 | * @uses urlsafeB64Encode |
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180 | */ |
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181 | public static function encode($payload, $key, $alg = 'HS256', $keyId = null, $head = null) |
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182 | { |
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183 | $header = array('typ' => 'JWT', 'alg' => $alg); |
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184 | if ($keyId !== null) { |
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185 | $header['kid'] = $keyId; |
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186 | } |
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187 | if (isset($head) && \is_array($head)) { |
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188 | $header = \array_merge($head, $header); |
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189 | } |
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190 | $segments = array(); |
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191 | $segments[] = static::urlsafeB64Encode(static::jsonEncode($header)); |
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192 | $segments[] = static::urlsafeB64Encode(static::jsonEncode($payload)); |
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193 | $signing_input = \implode('.', $segments); |
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194 | |||
195 | $signature = static::sign($signing_input, $key, $alg); |
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196 | $segments[] = static::urlsafeB64Encode($signature); |
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197 | |||
198 | return \implode('.', $segments); |
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199 | } |
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200 | |||
201 | /** |
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202 | * Sign a string with a given key and algorithm. |
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203 | * |
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204 | * @param string $msg The message to sign |
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205 | * @param string|resource $key The secret key |
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206 | * @param string $alg The signing algorithm. |
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618 | daniel-mar | 207 | * Supported algorithms are 'ES384','ES256', 'HS256', 'HS384', |
208 | * 'HS512', 'RS256', 'RS384', and 'RS512' |
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597 | daniel-mar | 209 | * |
210 | * @return string An encrypted message |
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211 | * |
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637 | daniel-mar | 212 | * @throws DomainException Unsupported algorithm or bad key was specified |
597 | daniel-mar | 213 | */ |
214 | public static function sign($msg, $key, $alg = 'HS256') |
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215 | { |
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216 | if (empty(static::$supported_algs[$alg])) { |
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217 | throw new DomainException('Algorithm not supported'); |
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218 | } |
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219 | list($function, $algorithm) = static::$supported_algs[$alg]; |
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220 | switch ($function) { |
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221 | case 'hash_hmac': |
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222 | return \hash_hmac($algorithm, $msg, $key, true); |
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223 | case 'openssl': |
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224 | $signature = ''; |
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225 | $success = \openssl_sign($msg, $signature, $key, $algorithm); |
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226 | if (!$success) { |
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227 | throw new DomainException("OpenSSL unable to sign data"); |
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228 | } |
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637 | daniel-mar | 229 | if ($alg === 'ES256') { |
230 | $signature = self::signatureFromDER($signature, 256); |
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231 | } elseif ($alg === 'ES384') { |
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232 | $signature = self::signatureFromDER($signature, 384); |
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233 | } |
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234 | return $signature; |
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235 | case 'sodium_crypto': |
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236 | if (!function_exists('sodium_crypto_sign_detached')) { |
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237 | throw new DomainException('libsodium is not available'); |
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238 | } |
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239 | try { |
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240 | // The last non-empty line is used as the key. |
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241 | $lines = array_filter(explode("\n", $key)); |
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242 | $key = base64_decode(end($lines)); |
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243 | return sodium_crypto_sign_detached($msg, $key); |
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244 | } catch (Exception $e) { |
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245 | throw new DomainException($e->getMessage(), 0, $e); |
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246 | } |
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597 | daniel-mar | 247 | } |
248 | } |
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249 | |||
250 | /** |
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251 | * Verify a signature with the message, key and method. Not all methods |
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252 | * are symmetric, so we must have a separate verify and sign method. |
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253 | * |
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254 | * @param string $msg The original message (header and body) |
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255 | * @param string $signature The original signature |
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256 | * @param string|resource $key For HS*, a string key works. for RS*, must be a resource of an openssl public key |
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257 | * @param string $alg The algorithm |
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258 | * |
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259 | * @return bool |
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260 | * |
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637 | daniel-mar | 261 | * @throws DomainException Invalid Algorithm, bad key, or OpenSSL failure |
597 | daniel-mar | 262 | */ |
263 | private static function verify($msg, $signature, $key, $alg) |
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264 | { |
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265 | if (empty(static::$supported_algs[$alg])) { |
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266 | throw new DomainException('Algorithm not supported'); |
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267 | } |
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268 | |||
269 | list($function, $algorithm) = static::$supported_algs[$alg]; |
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270 | switch ($function) { |
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271 | case 'openssl': |
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272 | $success = \openssl_verify($msg, $signature, $key, $algorithm); |
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273 | if ($success === 1) { |
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274 | return true; |
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275 | } elseif ($success === 0) { |
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276 | return false; |
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277 | } |
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278 | // returns 1 on success, 0 on failure, -1 on error. |
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279 | throw new DomainException( |
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280 | 'OpenSSL error: ' . \openssl_error_string() |
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281 | ); |
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637 | daniel-mar | 282 | case 'sodium_crypto': |
283 | if (!function_exists('sodium_crypto_sign_verify_detached')) { |
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284 | throw new DomainException('libsodium is not available'); |
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285 | } |
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286 | try { |
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287 | // The last non-empty line is used as the key. |
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288 | $lines = array_filter(explode("\n", $key)); |
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289 | $key = base64_decode(end($lines)); |
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290 | return sodium_crypto_sign_verify_detached($signature, $msg, $key); |
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291 | } catch (Exception $e) { |
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292 | throw new DomainException($e->getMessage(), 0, $e); |
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293 | } |
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597 | daniel-mar | 294 | case 'hash_hmac': |
295 | default: |
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296 | $hash = \hash_hmac($algorithm, $msg, $key, true); |
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679 | daniel-mar | 297 | return self::constantTimeEquals($signature, $hash); |
597 | daniel-mar | 298 | } |
299 | } |
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300 | |||
301 | /** |
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302 | * Decode a JSON string into a PHP object. |
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303 | * |
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304 | * @param string $input JSON string |
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305 | * |
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306 | * @return object Object representation of JSON string |
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307 | * |
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308 | * @throws DomainException Provided string was invalid JSON |
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309 | */ |
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310 | public static function jsonDecode($input) |
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311 | { |
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312 | if (\version_compare(PHP_VERSION, '5.4.0', '>=') && !(\defined('JSON_C_VERSION') && PHP_INT_SIZE > 4)) { |
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313 | /** In PHP >=5.4.0, json_decode() accepts an options parameter, that allows you |
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314 | * to specify that large ints (like Steam Transaction IDs) should be treated as |
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315 | * strings, rather than the PHP default behaviour of converting them to floats. |
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316 | */ |
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317 | $obj = \json_decode($input, false, 512, JSON_BIGINT_AS_STRING); |
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318 | } else { |
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319 | /** Not all servers will support that, however, so for older versions we must |
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320 | * manually detect large ints in the JSON string and quote them (thus converting |
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321 | *them to strings) before decoding, hence the preg_replace() call. |
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322 | */ |
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323 | $max_int_length = \strlen((string) PHP_INT_MAX) - 1; |
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324 | $json_without_bigints = \preg_replace('/:\s*(-?\d{'.$max_int_length.',})/', ': "$1"', $input); |
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325 | $obj = \json_decode($json_without_bigints); |
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326 | } |
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327 | |||
328 | if ($errno = \json_last_error()) { |
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329 | static::handleJsonError($errno); |
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330 | } elseif ($obj === null && $input !== 'null') { |
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331 | throw new DomainException('Null result with non-null input'); |
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332 | } |
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333 | return $obj; |
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334 | } |
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335 | |||
336 | /** |
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337 | * Encode a PHP object into a JSON string. |
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338 | * |
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339 | * @param object|array $input A PHP object or array |
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340 | * |
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341 | * @return string JSON representation of the PHP object or array |
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342 | * |
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343 | * @throws DomainException Provided object could not be encoded to valid JSON |
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344 | */ |
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345 | public static function jsonEncode($input) |
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346 | { |
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347 | $json = \json_encode($input); |
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348 | if ($errno = \json_last_error()) { |
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349 | static::handleJsonError($errno); |
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350 | } elseif ($json === 'null' && $input !== null) { |
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351 | throw new DomainException('Null result with non-null input'); |
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352 | } |
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353 | return $json; |
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354 | } |
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355 | |||
356 | /** |
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357 | * Decode a string with URL-safe Base64. |
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358 | * |
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359 | * @param string $input A Base64 encoded string |
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360 | * |
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361 | * @return string A decoded string |
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362 | */ |
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363 | public static function urlsafeB64Decode($input) |
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364 | { |
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365 | $remainder = \strlen($input) % 4; |
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366 | if ($remainder) { |
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367 | $padlen = 4 - $remainder; |
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368 | $input .= \str_repeat('=', $padlen); |
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369 | } |
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370 | return \base64_decode(\strtr($input, '-_', '+/')); |
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371 | } |
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372 | |||
373 | /** |
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374 | * Encode a string with URL-safe Base64. |
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375 | * |
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376 | * @param string $input The string you want encoded |
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377 | * |
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378 | * @return string The base64 encode of what you passed in |
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379 | */ |
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380 | public static function urlsafeB64Encode($input) |
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381 | { |
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382 | return \str_replace('=', '', \strtr(\base64_encode($input), '+/', '-_')); |
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383 | } |
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384 | |||
679 | daniel-mar | 385 | |
597 | daniel-mar | 386 | /** |
679 | daniel-mar | 387 | * Determine if an algorithm has been provided for each Key |
388 | * |
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389 | * @param Key|array<Key>|mixed $keyOrKeyArray |
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390 | * @param string|null $kid |
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391 | * |
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392 | * @throws UnexpectedValueException |
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393 | * |
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394 | * @return array containing the keyMaterial and algorithm |
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395 | */ |
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396 | private static function getKeyMaterialAndAlgorithm($keyOrKeyArray, $kid = null) |
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397 | { |
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398 | if ( |
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399 | is_string($keyOrKeyArray) |
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400 | || is_resource($keyOrKeyArray) |
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401 | || $keyOrKeyArray instanceof OpenSSLAsymmetricKey |
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402 | ) { |
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403 | return array($keyOrKeyArray, null); |
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404 | } |
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405 | |||
406 | if ($keyOrKeyArray instanceof Key) { |
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407 | return array($keyOrKeyArray->getKeyMaterial(), $keyOrKeyArray->getAlgorithm()); |
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408 | } |
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409 | |||
410 | if (is_array($keyOrKeyArray) || $keyOrKeyArray instanceof ArrayAccess) { |
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411 | if (!isset($kid)) { |
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412 | throw new UnexpectedValueException('"kid" empty, unable to lookup correct key'); |
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413 | } |
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414 | if (!isset($keyOrKeyArray[$kid])) { |
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415 | throw new UnexpectedValueException('"kid" invalid, unable to lookup correct key'); |
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416 | } |
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417 | |||
418 | $key = $keyOrKeyArray[$kid]; |
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419 | |||
420 | if ($key instanceof Key) { |
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421 | return array($key->getKeyMaterial(), $key->getAlgorithm()); |
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422 | } |
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423 | |||
424 | return array($key, null); |
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425 | } |
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426 | |||
427 | throw new UnexpectedValueException( |
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428 | '$keyOrKeyArray must be a string|resource key, an array of string|resource keys, ' |
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429 | . 'an instance of Firebase\JWT\Key key or an array of Firebase\JWT\Key keys' |
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430 | ); |
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431 | } |
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432 | |||
433 | /** |
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434 | * @param string $left |
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435 | * @param string $right |
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436 | * @return bool |
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437 | */ |
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438 | public static function constantTimeEquals($left, $right) |
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439 | { |
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440 | if (\function_exists('hash_equals')) { |
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441 | return \hash_equals($left, $right); |
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442 | } |
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443 | $len = \min(static::safeStrlen($left), static::safeStrlen($right)); |
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444 | |||
445 | $status = 0; |
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446 | for ($i = 0; $i < $len; $i++) { |
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447 | $status |= (\ord($left[$i]) ^ \ord($right[$i])); |
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448 | } |
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449 | $status |= (static::safeStrlen($left) ^ static::safeStrlen($right)); |
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450 | |||
451 | return ($status === 0); |
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452 | } |
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453 | |||
454 | /** |
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597 | daniel-mar | 455 | * Helper method to create a JSON error. |
456 | * |
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457 | * @param int $errno An error number from json_last_error() |
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458 | * |
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459 | * @return void |
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460 | */ |
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461 | private static function handleJsonError($errno) |
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462 | { |
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463 | $messages = array( |
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464 | JSON_ERROR_DEPTH => 'Maximum stack depth exceeded', |
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465 | JSON_ERROR_STATE_MISMATCH => 'Invalid or malformed JSON', |
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466 | JSON_ERROR_CTRL_CHAR => 'Unexpected control character found', |
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467 | JSON_ERROR_SYNTAX => 'Syntax error, malformed JSON', |
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468 | JSON_ERROR_UTF8 => 'Malformed UTF-8 characters' //PHP >= 5.3.3 |
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469 | ); |
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470 | throw new DomainException( |
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471 | isset($messages[$errno]) |
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472 | ? $messages[$errno] |
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473 | : 'Unknown JSON error: ' . $errno |
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474 | ); |
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475 | } |
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476 | |||
477 | /** |
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478 | * Get the number of bytes in cryptographic strings. |
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479 | * |
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480 | * @param string $str |
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481 | * |
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482 | * @return int |
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483 | */ |
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484 | private static function safeStrlen($str) |
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485 | { |
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486 | if (\function_exists('mb_strlen')) { |
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487 | return \mb_strlen($str, '8bit'); |
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488 | } |
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489 | return \strlen($str); |
||
490 | } |
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491 | |||
492 | /** |
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493 | * Convert an ECDSA signature to an ASN.1 DER sequence |
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494 | * |
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495 | * @param string $sig The ECDSA signature to convert |
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496 | * @return string The encoded DER object |
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497 | */ |
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498 | private static function signatureToDER($sig) |
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499 | { |
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500 | // Separate the signature into r-value and s-value |
||
501 | list($r, $s) = \str_split($sig, (int) (\strlen($sig) / 2)); |
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502 | |||
503 | // Trim leading zeros |
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504 | $r = \ltrim($r, "\x00"); |
||
505 | $s = \ltrim($s, "\x00"); |
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506 | |||
507 | // Convert r-value and s-value from unsigned big-endian integers to |
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508 | // signed two's complement |
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509 | if (\ord($r[0]) > 0x7f) { |
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510 | $r = "\x00" . $r; |
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511 | } |
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512 | if (\ord($s[0]) > 0x7f) { |
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513 | $s = "\x00" . $s; |
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514 | } |
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515 | |||
516 | return self::encodeDER( |
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517 | self::ASN1_SEQUENCE, |
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518 | self::encodeDER(self::ASN1_INTEGER, $r) . |
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519 | self::encodeDER(self::ASN1_INTEGER, $s) |
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520 | ); |
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521 | } |
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522 | |||
523 | /** |
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524 | * Encodes a value into a DER object. |
||
525 | * |
||
526 | * @param int $type DER tag |
||
527 | * @param string $value the value to encode |
||
528 | * @return string the encoded object |
||
529 | */ |
||
530 | private static function encodeDER($type, $value) |
||
531 | { |
||
532 | $tag_header = 0; |
||
533 | if ($type === self::ASN1_SEQUENCE) { |
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534 | $tag_header |= 0x20; |
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535 | } |
||
536 | |||
537 | // Type |
||
538 | $der = \chr($tag_header | $type); |
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539 | |||
540 | // Length |
||
541 | $der .= \chr(\strlen($value)); |
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542 | |||
543 | return $der . $value; |
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544 | } |
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545 | |||
546 | /** |
||
547 | * Encodes signature from a DER object. |
||
548 | * |
||
549 | * @param string $der binary signature in DER format |
||
550 | * @param int $keySize the number of bits in the key |
||
551 | * @return string the signature |
||
552 | */ |
||
553 | private static function signatureFromDER($der, $keySize) |
||
554 | { |
||
555 | // OpenSSL returns the ECDSA signatures as a binary ASN.1 DER SEQUENCE |
||
556 | list($offset, $_) = self::readDER($der); |
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557 | list($offset, $r) = self::readDER($der, $offset); |
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558 | list($offset, $s) = self::readDER($der, $offset); |
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559 | |||
560 | // Convert r-value and s-value from signed two's compliment to unsigned |
||
561 | // big-endian integers |
||
562 | $r = \ltrim($r, "\x00"); |
||
563 | $s = \ltrim($s, "\x00"); |
||
564 | |||
565 | // Pad out r and s so that they are $keySize bits long |
||
566 | $r = \str_pad($r, $keySize / 8, "\x00", STR_PAD_LEFT); |
||
567 | $s = \str_pad($s, $keySize / 8, "\x00", STR_PAD_LEFT); |
||
568 | |||
569 | return $r . $s; |
||
570 | } |
||
571 | |||
572 | /** |
||
573 | * Reads binary DER-encoded data and decodes into a single object |
||
574 | * |
||
575 | * @param string $der the binary data in DER format |
||
576 | * @param int $offset the offset of the data stream containing the object |
||
577 | * to decode |
||
578 | * @return array [$offset, $data] the new offset and the decoded object |
||
579 | */ |
||
580 | private static function readDER($der, $offset = 0) |
||
581 | { |
||
582 | $pos = $offset; |
||
583 | $size = \strlen($der); |
||
584 | $constructed = (\ord($der[$pos]) >> 5) & 0x01; |
||
585 | $type = \ord($der[$pos++]) & 0x1f; |
||
586 | |||
587 | // Length |
||
588 | $len = \ord($der[$pos++]); |
||
589 | if ($len & 0x80) { |
||
590 | $n = $len & 0x1f; |
||
591 | $len = 0; |
||
592 | while ($n-- && $pos < $size) { |
||
593 | $len = ($len << 8) | \ord($der[$pos++]); |
||
594 | } |
||
595 | } |
||
596 | |||
597 | // Value |
||
598 | if ($type == self::ASN1_BIT_STRING) { |
||
599 | $pos++; // Skip the first contents octet (padding indicator) |
||
600 | $data = \substr($der, $pos, $len - 1); |
||
601 | $pos += $len - 1; |
||
602 | } elseif (!$constructed) { |
||
603 | $data = \substr($der, $pos, $len); |
||
604 | $pos += $len; |
||
605 | } else { |
||
606 | $data = null; |
||
607 | } |
||
608 | |||
609 | return array($pos, $data); |
||
610 | } |
||
611 | } |