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Diffstat (limited to 'plugins/jetpack/class.jetpack-signature.php')
-rw-r--r-- | plugins/jetpack/class.jetpack-signature.php | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/plugins/jetpack/class.jetpack-signature.php b/plugins/jetpack/class.jetpack-signature.php new file mode 100644 index 00000000..8d925d7d --- /dev/null +++ b/plugins/jetpack/class.jetpack-signature.php @@ -0,0 +1,266 @@ +<?php + +// These constants can be set in wp-config.php to ensure sites behind proxies will still work. +// Setting these constants, though, is *not* the preferred method. It's better to configure +// the proxy to send the X-Forwarded-Port header. +defined( 'JETPACK_SIGNATURE__HTTP_PORT' ) or define( 'JETPACK_SIGNATURE__HTTP_PORT' , 80 ); +defined( 'JETPACK_SIGNATURE__HTTPS_PORT' ) or define( 'JETPACK_SIGNATURE__HTTPS_PORT', 443 ); + +class Jetpack_Signature { + public $token; + public $secret; + + function __construct( $access_token, $time_diff = 0 ) { + $secret = explode( '.', $access_token ); + if ( 2 != count( $secret ) ) + return; + + $this->token = $secret[0]; + $this->secret = $secret[1]; + $this->time_diff = $time_diff; + } + + function sign_current_request( $override = array() ) { + if ( isset( $override['scheme'] ) ) { + $scheme = $override['scheme']; + if ( !in_array( $scheme, array( 'http', 'https' ) ) ) { + return new Jetpack_Error( 'invalid_scheme', 'Invalid URL scheme' ); + } + } else { + if ( is_ssl() ) { + $scheme = 'https'; + } else { + $scheme = 'http'; + } + } + + $host_port = isset( $_SERVER['HTTP_X_FORWARDED_PORT'] ) ? $_SERVER['HTTP_X_FORWARDED_PORT'] : $_SERVER['SERVER_PORT']; + + /** + * Note: This port logic is tested in the Jetpack_Cxn_Tests->test__server_port_value() test. + * Please update the test if any changes are made in this logic. + */ + if ( is_ssl() ) { + // 443: Standard Port + // 80: Assume we're behind a proxy without X-Forwarded-Port. Hardcoding "80" here means most sites + // with SSL termination proxies (self-served, Cloudflare, etc.) don't need to fiddle with + // the JETPACK_SIGNATURE__HTTPS_PORT constant. The code also implies we can't talk to a + // site at https://example.com:80/ (which would be a strange configuration). + // JETPACK_SIGNATURE__HTTPS_PORT: Set this constant in wp-config.php to the back end webserver's port + // if the site is behind a proxy running on port 443 without + // X-Forwarded-Port and the back end's port is *not* 80. It's better, + // though, to configure the proxy to send X-Forwarded-Port. + $port = in_array( $host_port, array( 443, 80, JETPACK_SIGNATURE__HTTPS_PORT ) ) ? '' : $host_port; + } else { + // 80: Standard Port + // JETPACK_SIGNATURE__HTTPS_PORT: Set this constant in wp-config.php to the back end webserver's port + // if the site is behind a proxy running on port 80 without + // X-Forwarded-Port. It's better, though, to configure the proxy to + // send X-Forwarded-Port. + $port = in_array( $host_port, array( 80, JETPACK_SIGNATURE__HTTP_PORT ) ) ? '' : $host_port; + } + + $url = "{$scheme}://{$_SERVER['HTTP_HOST']}:{$port}" . stripslashes( $_SERVER['REQUEST_URI'] ); + + if ( array_key_exists( 'body', $override ) && ! empty( $override['body'] ) ) { + $body = $override['body']; + } else if ( 'POST' == strtoupper( $_SERVER['REQUEST_METHOD'] ) ) { + $body = isset( $GLOBALS['HTTP_RAW_POST_DATA'] ) ? $GLOBALS['HTTP_RAW_POST_DATA'] : null; + + // Convert the $_POST to the body, if the body was empty. This is how arrays are hashed + // and encoded on the Jetpack side. + if ( defined( 'IS_WPCOM' ) && IS_WPCOM ) { + if ( empty( $body ) && is_array( $_POST ) && count( $_POST ) > 0 ) { + $body = $_POST; + } + } + } else if ( 'PUT' == strtoupper( $_SERVER['REQUEST_METHOD'] ) ) { + // This is a little strange-looking, but there doesn't seem to be another way to get the PUT body + $raw_put_data = file_get_contents( 'php://input' ); + parse_str( $raw_put_data, $body ); + + if ( defined( 'IS_WPCOM' ) && IS_WPCOM ) { + $put_data = json_decode( $raw_put_data, true ); + if ( is_array( $put_data ) && count( $put_data ) > 0 ) { + $body = $put_data; + } + } + } else { + $body = null; + } + + if ( empty( $body ) ) { + $body = null; + } + + $a = array(); + foreach ( array( 'token', 'timestamp', 'nonce', 'body-hash' ) as $parameter ) { + if ( isset( $override[$parameter] ) ) { + $a[$parameter] = $override[$parameter]; + } else { + $a[$parameter] = isset( $_GET[$parameter] ) ? stripslashes( $_GET[$parameter] ) : ''; + } + } + + $method = isset( $override['method'] ) ? $override['method'] : $_SERVER['REQUEST_METHOD']; + return $this->sign_request( $a['token'], $a['timestamp'], $a['nonce'], $a['body-hash'], $method, $url, $body, true ); + } + + // body_hash v. body-hash is annoying. Refactor to accept an array? + function sign_request( $token = '', $timestamp = 0, $nonce = '', $body_hash = '', $method = '', $url = '', $body = null, $verify_body_hash = true ) { + if ( !$this->secret ) { + return new Jetpack_Error( 'invalid_secret', 'Invalid secret' ); + } + + if ( !$this->token ) { + return new Jetpack_Error( 'invalid_token', 'Invalid token' ); + } + + list( $token ) = explode( '.', $token ); + + if ( 0 !== strpos( $token, "$this->token:" ) ) { + return new Jetpack_Error( 'token_mismatch', 'Incorrect token' ); + } + + // If we got an array at this point, let's encode it, so we can see what it looks like as a string. + if ( is_array( $body ) ) { + if ( count( $body ) > 0 ) { + $body = json_encode( $body ); + + } else { + $body = ''; + } + } + + $required_parameters = array( 'token', 'timestamp', 'nonce', 'method', 'url' ); + if ( !is_null( $body ) ) { + $required_parameters[] = 'body_hash'; + if ( !is_string( $body ) ) { + return new Jetpack_Error( 'invalid_body', 'Body is malformed.' ); + } + } + + foreach ( $required_parameters as $required ) { + if ( !is_scalar( $$required ) ) { + return new Jetpack_Error( 'invalid_signature', sprintf( 'The required "%s" parameter is malformed.', str_replace( '_', '-', $required ) ) ); + } + + if ( !strlen( $$required ) ) { + return new Jetpack_Error( 'invalid_signature', sprintf( 'The required "%s" parameter is missing.', str_replace( '_', '-', $required ) ) ); + } + } + + if ( empty( $body ) ) { + if ( $body_hash ) { + return new Jetpack_Error( 'invalid_body_hash', 'The body hash does not match.' ); + } + } else { + if ( $verify_body_hash && jetpack_sha1_base64( $body ) !== $body_hash ) { + return new Jetpack_Error( 'invalid_body_hash', 'The body hash does not match.' ); + } + } + + $parsed = parse_url( $url ); + if ( !isset( $parsed['host'] ) ) { + return new Jetpack_Error( 'invalid_signature', sprintf( 'The required "%s" parameter is malformed.', 'url' ) ); + } + + if ( !empty( $parsed['port'] ) ) { + $port = $parsed['port']; + } else { + if ( 'http' == $parsed['scheme'] ) { + $port = 80; + } else if ( 'https' == $parsed['scheme'] ) { + $port = 443; + } else { + return new Jetpack_Error( 'unknown_scheme_port', "The scheme's port is unknown" ); + } + } + + if ( !ctype_digit( "$timestamp" ) || 10 < strlen( $timestamp ) ) { // If Jetpack is around in 275 years, you can blame mdawaffe for the bug. + return new Jetpack_Error( 'invalid_signature', sprintf( 'The required "%s" parameter is malformed.', 'timestamp' ) ); + } + + $local_time = $timestamp - $this->time_diff; + if ( $local_time < time() - 600 || $local_time > time() + 300 ) { + return new Jetpack_Error( 'invalid_signature', 'The timestamp is too old.' ); + } + + if ( 12 < strlen( $nonce ) || preg_match( '/[^a-zA-Z0-9]/', $nonce ) ) { + return new Jetpack_Error( 'invalid_signature', sprintf( 'The required "%s" parameter is malformed.', 'nonce' ) ); + } + + $normalized_request_pieces = array( + $token, + $timestamp, + $nonce, + $body_hash, + strtoupper( $method ), + strtolower( $parsed['host'] ), + $port, + $parsed['path'], + // Normalized Query String + ); + + $normalized_request_pieces = array_merge( $normalized_request_pieces, $this->normalized_query_parameters( isset( $parsed['query'] ) ? $parsed['query'] : '' ) ); + $flat_normalized_request_pieces = array(); + foreach ($normalized_request_pieces as $piece) { + if ( is_array( $piece ) ) { + foreach ( $piece as $subpiece ) { + $flat_normalized_request_pieces[] = $subpiece; + } + } else { + $flat_normalized_request_pieces[] = $piece; + } + } + $normalized_request_pieces = $flat_normalized_request_pieces; + + $normalized_request_string = join( "\n", $normalized_request_pieces ) . "\n"; + + return base64_encode( hash_hmac( 'sha1', $normalized_request_string, $this->secret, true ) ); + } + + function normalized_query_parameters( $query_string ) { + parse_str( $query_string, $array ); + if ( get_magic_quotes_gpc() ) + $array = stripslashes_deep( $array ); + + unset( $array['signature'] ); + + $names = array_keys( $array ); + $values = array_values( $array ); + + $names = array_map( array( $this, 'encode_3986' ), $names ); + $values = array_map( array( $this, 'encode_3986' ), $values ); + + $pairs = array_map( array( $this, 'join_with_equal_sign' ), $names, $values ); + + sort( $pairs ); + + return $pairs; + } + + function encode_3986( $string_or_array ) { + if ( is_array( $string_or_array ) ) { + return array_map( array( $this, 'encode_3986' ), $string_or_array ); + } + + $string_or_array = rawurlencode( $string_or_array ); + return str_replace( '%7E', '~', $string_or_array ); // prior to PHP 5.3, rawurlencode was RFC 1738 + } + + function join_with_equal_sign( $name, $value ) { + if ( is_array( $value ) ) { + $result = array(); + foreach ( $value as $array_key => $array_value ) { + $result[] = $name . '[' . $array_key . ']' . '=' . $array_value; + } + return $result; + } + return "{$name}={$value}"; + } +} + +function jetpack_sha1_base64( $text ) { + return base64_encode( sha1( $text, true ) ); +} |