class.jetpack-signature.php
| 1 | <?php |
| 2 | |
| 3 | // These constants can be set in wp-config.php to ensure sites behind proxies will still work. |
| 4 | // Setting these constants, though, is *not* the preferred method. It's better to configure |
| 5 | // the proxy to send the X-Forwarded-Port header. |
| 6 | defined( 'JETPACK_SIGNATURE__HTTP_PORT' ) or define( 'JETPACK_SIGNATURE__HTTP_PORT' , 80 ); |
| 7 | defined( 'JETPACK_SIGNATURE__HTTPS_PORT' ) or define( 'JETPACK_SIGNATURE__HTTPS_PORT', 443 ); |
| 8 | |
| 9 | class Jetpack_Signature { |
| 10 | public $token; |
| 11 | public $secret; |
| 12 | |
| 13 | function __construct( $access_token, $time_diff = 0 ) { |
| 14 | $secret = explode( '.', $access_token ); |
| 15 | if ( 2 != count( $secret ) ) |
| 16 | return; |
| 17 | |
| 18 | $this->token = $secret[0]; |
| 19 | $this->secret = $secret[1]; |
| 20 | $this->time_diff = $time_diff; |
| 21 | } |
| 22 | |
| 23 | function sign_current_request( $override = array() ) { |
| 24 | if ( isset( $override['scheme'] ) ) { |
| 25 | $scheme = $override['scheme']; |
| 26 | if ( !in_array( $scheme, array( 'http', 'https' ) ) ) { |
| 27 | return new Jetpack_Error( 'invalid_scheme', 'Invalid URL scheme' ); |
| 28 | } |
| 29 | } else { |
| 30 | if ( is_ssl() ) { |
| 31 | $scheme = 'https'; |
| 32 | } else { |
| 33 | $scheme = 'http'; |
| 34 | } |
| 35 | } |
| 36 | |
| 37 | $host_port = isset( $_SERVER['HTTP_X_FORWARDED_PORT'] ) ? $_SERVER['HTTP_X_FORWARDED_PORT'] : $_SERVER['SERVER_PORT']; |
| 38 | |
| 39 | /** |
| 40 | * Note: This port logic is tested in the Jetpack_Cxn_Tests->test__server_port_value() test. |
| 41 | * Please update the test if any changes are made in this logic. |
| 42 | */ |
| 43 | if ( is_ssl() ) { |
| 44 | // 443: Standard Port |
| 45 | // 80: Assume we're behind a proxy without X-Forwarded-Port. Hardcoding "80" here means most sites |
| 46 | // with SSL termination proxies (self-served, Cloudflare, etc.) don't need to fiddle with |
| 47 | // the JETPACK_SIGNATURE__HTTPS_PORT constant. The code also implies we can't talk to a |
| 48 | // site at https://example.com:80/ (which would be a strange configuration). |
| 49 | // JETPACK_SIGNATURE__HTTPS_PORT: Set this constant in wp-config.php to the back end webserver's port |
| 50 | // if the site is behind a proxy running on port 443 without |
| 51 | // X-Forwarded-Port and the back end's port is *not* 80. It's better, |
| 52 | // though, to configure the proxy to send X-Forwarded-Port. |
| 53 | $port = in_array( $host_port, array( 443, 80, JETPACK_SIGNATURE__HTTPS_PORT ) ) ? '' : $host_port; |
| 54 | } else { |
| 55 | // 80: Standard Port |
| 56 | // JETPACK_SIGNATURE__HTTPS_PORT: Set this constant in wp-config.php to the back end webserver's port |
| 57 | // if the site is behind a proxy running on port 80 without |
| 58 | // X-Forwarded-Port. It's better, though, to configure the proxy to |
| 59 | // send X-Forwarded-Port. |
| 60 | $port = in_array( $host_port, array( 80, JETPACK_SIGNATURE__HTTP_PORT ) ) ? '' : $host_port; |
| 61 | } |
| 62 | |
| 63 | $url = "{$scheme}://{$_SERVER['HTTP_HOST']}:{$port}" . stripslashes( $_SERVER['REQUEST_URI'] ); |
| 64 | |
| 65 | if ( array_key_exists( 'body', $override ) && ! empty( $override['body'] ) ) { |
| 66 | $body = $override['body']; |
| 67 | } else if ( 'POST' == strtoupper( $_SERVER['REQUEST_METHOD'] ) ) { |
| 68 | $body = isset( $GLOBALS['HTTP_RAW_POST_DATA'] ) ? $GLOBALS['HTTP_RAW_POST_DATA'] : null; |
| 69 | |
| 70 | // Convert the $_POST to the body, if the body was empty. This is how arrays are hashed |
| 71 | // and encoded on the Jetpack side. |
| 72 | if ( defined( 'IS_WPCOM' ) && IS_WPCOM ) { |
| 73 | if ( empty( $body ) && is_array( $_POST ) && count( $_POST ) > 0 ) { |
| 74 | $body = $_POST; |
| 75 | } |
| 76 | } |
| 77 | } else if ( 'PUT' == strtoupper( $_SERVER['REQUEST_METHOD'] ) ) { |
| 78 | // This is a little strange-looking, but there doesn't seem to be another way to get the PUT body |
| 79 | $raw_put_data = file_get_contents( 'php://input' ); |
| 80 | parse_str( $raw_put_data, $body ); |
| 81 | |
| 82 | if ( defined( 'IS_WPCOM' ) && IS_WPCOM ) { |
| 83 | $put_data = json_decode( $raw_put_data, true ); |
| 84 | if ( is_array( $put_data ) && count( $put_data ) > 0 ) { |
| 85 | $body = $put_data; |
| 86 | } |
| 87 | } |
| 88 | } else { |
| 89 | $body = null; |
| 90 | } |
| 91 | |
| 92 | if ( empty( $body ) ) { |
| 93 | $body = null; |
| 94 | } |
| 95 | |
| 96 | $a = array(); |
| 97 | foreach ( array( 'token', 'timestamp', 'nonce', 'body-hash' ) as $parameter ) { |
| 98 | if ( isset( $override[$parameter] ) ) { |
| 99 | $a[$parameter] = $override[$parameter]; |
| 100 | } else { |
| 101 | $a[$parameter] = isset( $_GET[$parameter] ) ? stripslashes( $_GET[$parameter] ) : ''; |
| 102 | } |
| 103 | } |
| 104 | |
| 105 | $method = isset( $override['method'] ) ? $override['method'] : $_SERVER['REQUEST_METHOD']; |
| 106 | return $this->sign_request( $a['token'], $a['timestamp'], $a['nonce'], $a['body-hash'], $method, $url, $body, true ); |
| 107 | } |
| 108 | |
| 109 | // body_hash v. body-hash is annoying. Refactor to accept an array? |
| 110 | function sign_request( $token = '', $timestamp = 0, $nonce = '', $body_hash = '', $method = '', $url = '', $body = null, $verify_body_hash = true ) { |
| 111 | if ( !$this->secret ) { |
| 112 | return new Jetpack_Error( 'invalid_secret', 'Invalid secret' ); |
| 113 | } |
| 114 | |
| 115 | if ( !$this->token ) { |
| 116 | return new Jetpack_Error( 'invalid_token', 'Invalid token' ); |
| 117 | } |
| 118 | |
| 119 | list( $token ) = explode( '.', $token ); |
| 120 | |
| 121 | if ( 0 !== strpos( $token, "$this->token:" ) ) { |
| 122 | return new Jetpack_Error( 'token_mismatch', 'Incorrect token' ); |
| 123 | } |
| 124 | |
| 125 | // If we got an array at this point, let's encode it, so we can see what it looks like as a string. |
| 126 | if ( is_array( $body ) ) { |
| 127 | if ( count( $body ) > 0 ) { |
| 128 | $body = json_encode( $body ); |
| 129 | |
| 130 | } else { |
| 131 | $body = ''; |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | $required_parameters = array( 'token', 'timestamp', 'nonce', 'method', 'url' ); |
| 136 | if ( !is_null( $body ) ) { |
| 137 | $required_parameters[] = 'body_hash'; |
| 138 | if ( !is_string( $body ) ) { |
| 139 | return new Jetpack_Error( 'invalid_body', 'Body is malformed.' ); |
| 140 | } |
| 141 | } |
| 142 | |
| 143 | foreach ( $required_parameters as $required ) { |
| 144 | if ( !is_scalar( $$required ) ) { |
| 145 | return new Jetpack_Error( 'invalid_signature', sprintf( 'The required "%s" parameter is malformed.', str_replace( '_', '-', $required ) ) ); |
| 146 | } |
| 147 | |
| 148 | if ( !strlen( $$required ) ) { |
| 149 | return new Jetpack_Error( 'invalid_signature', sprintf( 'The required "%s" parameter is missing.', str_replace( '_', '-', $required ) ) ); |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | if ( empty( $body ) ) { |
| 154 | if ( $body_hash ) { |
| 155 | return new Jetpack_Error( 'invalid_body_hash', 'The body hash does not match.' ); |
| 156 | } |
| 157 | } else { |
| 158 | if ( $verify_body_hash && jetpack_sha1_base64( $body ) !== $body_hash ) { |
| 159 | return new Jetpack_Error( 'invalid_body_hash', 'The body hash does not match.' ); |
| 160 | } |
| 161 | } |
| 162 | |
| 163 | $parsed = parse_url( $url ); |
| 164 | if ( !isset( $parsed['host'] ) ) { |
| 165 | return new Jetpack_Error( 'invalid_signature', sprintf( 'The required "%s" parameter is malformed.', 'url' ) ); |
| 166 | } |
| 167 | |
| 168 | if ( !empty( $parsed['port'] ) ) { |
| 169 | $port = $parsed['port']; |
| 170 | } else { |
| 171 | if ( 'http' == $parsed['scheme'] ) { |
| 172 | $port = 80; |
| 173 | } else if ( 'https' == $parsed['scheme'] ) { |
| 174 | $port = 443; |
| 175 | } else { |
| 176 | return new Jetpack_Error( 'unknown_scheme_port', "The scheme's port is unknown" ); |
| 177 | } |
| 178 | } |
| 179 | |
| 180 | if ( !ctype_digit( "$timestamp" ) || 10 < strlen( $timestamp ) ) { // If Jetpack is around in 275 years, you can blame mdawaffe for the bug. |
| 181 | return new Jetpack_Error( 'invalid_signature', sprintf( 'The required "%s" parameter is malformed.', 'timestamp' ) ); |
| 182 | } |
| 183 | |
| 184 | $local_time = $timestamp - $this->time_diff; |
| 185 | if ( $local_time < time() - 600 || $local_time > time() + 300 ) { |
| 186 | return new Jetpack_Error( 'invalid_signature', 'The timestamp is too old.' ); |
| 187 | } |
| 188 | |
| 189 | if ( 12 < strlen( $nonce ) || preg_match( '/[^a-zA-Z0-9]/', $nonce ) ) { |
| 190 | return new Jetpack_Error( 'invalid_signature', sprintf( 'The required "%s" parameter is malformed.', 'nonce' ) ); |
| 191 | } |
| 192 | |
| 193 | $normalized_request_pieces = array( |
| 194 | $token, |
| 195 | $timestamp, |
| 196 | $nonce, |
| 197 | $body_hash, |
| 198 | strtoupper( $method ), |
| 199 | strtolower( $parsed['host'] ), |
| 200 | $port, |
| 201 | $parsed['path'], |
| 202 | // Normalized Query String |
| 203 | ); |
| 204 | |
| 205 | $normalized_request_pieces = array_merge( $normalized_request_pieces, $this->normalized_query_parameters( isset( $parsed['query'] ) ? $parsed['query'] : '' ) ); |
| 206 | $flat_normalized_request_pieces = array(); |
| 207 | foreach ($normalized_request_pieces as $piece) { |
| 208 | if ( is_array( $piece ) ) { |
| 209 | foreach ( $piece as $subpiece ) { |
| 210 | $flat_normalized_request_pieces[] = $subpiece; |
| 211 | } |
| 212 | } else { |
| 213 | $flat_normalized_request_pieces[] = $piece; |
| 214 | } |
| 215 | } |
| 216 | $normalized_request_pieces = $flat_normalized_request_pieces; |
| 217 | |
| 218 | $normalized_request_string = join( "\n", $normalized_request_pieces ) . "\n"; |
| 219 | |
| 220 | return base64_encode( hash_hmac( 'sha1', $normalized_request_string, $this->secret, true ) ); |
| 221 | } |
| 222 | |
| 223 | function normalized_query_parameters( $query_string ) { |
| 224 | parse_str( $query_string, $array ); |
| 225 | if ( get_magic_quotes_gpc() ) |
| 226 | $array = stripslashes_deep( $array ); |
| 227 | |
| 228 | unset( $array['signature'] ); |
| 229 | |
| 230 | $names = array_keys( $array ); |
| 231 | $values = array_values( $array ); |
| 232 | |
| 233 | $names = array_map( array( $this, 'encode_3986' ), $names ); |
| 234 | $values = array_map( array( $this, 'encode_3986' ), $values ); |
| 235 | |
| 236 | $pairs = array_map( array( $this, 'join_with_equal_sign' ), $names, $values ); |
| 237 | |
| 238 | sort( $pairs ); |
| 239 | |
| 240 | return $pairs; |
| 241 | } |
| 242 | |
| 243 | function encode_3986( $string_or_array ) { |
| 244 | if ( is_array( $string_or_array ) ) { |
| 245 | return array_map( array( $this, 'encode_3986' ), $string_or_array ); |
| 246 | } |
| 247 | |
| 248 | $string_or_array = rawurlencode( $string_or_array ); |
| 249 | return str_replace( '%7E', '~', $string_or_array ); // prior to PHP 5.3, rawurlencode was RFC 1738 |
| 250 | } |
| 251 | |
| 252 | function join_with_equal_sign( $name, $value ) { |
| 253 | if ( is_array( $value ) ) { |
| 254 | $result = array(); |
| 255 | foreach ( $value as $array_key => $array_value ) { |
| 256 | $result[] = $name . '[' . $array_key . ']' . '=' . $array_value; |
| 257 | } |
| 258 | return $result; |
| 259 | } |
| 260 | return "{$name}={$value}"; |
| 261 | } |
| 262 | } |
| 263 | |
| 264 | function jetpack_sha1_base64( $text ) { |
| 265 | return base64_encode( sha1( $text, true ) ); |
| 266 | } |
| 267 |