diff options
| -rw-r--r-- | eval_test.js | 158 | ||||
| -rw-r--r-- | testtag.html | 17 |
2 files changed, 123 insertions, 52 deletions
diff --git a/eval_test.js b/eval_test.js index ffdb0e9..64af781 100644 --- a/eval_test.js +++ b/eval_test.js @@ -143,75 +143,124 @@ var licenses = { } /** +* Determines if a block of javascript is trivial or not. +* +* true = trivial, false = nontrivial +* +*/ +function evaluate(script){ + console.log("%c Evaluating","color: red;") + console.log(script); + // Remove all the strings from the script so everything left is code. + // This gets rid of false positives (eval appearing in an innocent string) + // Note: Javascript strings can not take up more than one line + var nostr = script.replace(/'.+?'+/gm,""); + nostr = script.replace(/".+?"+/gm,""); + + return true; +} + +/** +* Looks at the output of the @license regex and determines if the +* license is good. +*/ +function license_valid(matches){ + // Being overly careful with safety checks + if(matches.length != 4){ + return false; + } + if(matches[1] != "@license"){ + return false; + } + if(licenses[matches[3]] === undefined){ + return false; + } + if(licenses[matches[3]]["Magnet link"] != matches[2]){ + return false; + } + return true; +} +/** * * Runs regexes to search for explicit delcarations of script * licenses on the argument. * It detects: * //@license, //@license-end -* //licstart, //licen -* Returns the identifier string of the license or "fail". +* //licstart, //licend +* +* We are assuming that the "stack depth" of @license tags can not exceed 1. +* If this isn't correct, we can make it recursive. * */ +// TODO: Known bug: extra \n chars thrown in at some splices function license_read(script_src){ if(typeof(script_src) != "string"){ return "fail" } - var license_attempts = []; - // comment regex - var comments = script_src.match(/(\/\*([^*]|[\r\n]|(\*+([^*/]|[\r\n])))*\*+\/)|(\/\/.*)/g); - if(comments == null){ - comments = []; - } - //console.log("%c comments:","color:green;") - //console.log(comments); + // @license regex + // /^(@license)\s([\S]+)\s([\S]+$)/gm + // @license-end regex + // ^(@license-end) - // Not sure if there is any better way to do this. - // More than one license section per file should be supported once we can edit scripts - // (this will be converted to edit the script instead of just read it) - for(var i = 0; i < comments.length; i++){ - if(comments[i] !== undefined){ - // @license regex - if(comments[i].match(/@license[^\S\n]+magnet:\S+[^\S\n]+\S+/g) != null){ - console.log("License start detected."); - var content = comments[i].match(/(?:magnet:\S+)(\s+.+)/g); - if(content != null){ - content[0].replace(/\s+/g," "); - content = content[0].split(" "); - var magnet = content[0]; - var identifier = ""; - for(var i = 1; i < content.length; i++){ - if(i == 1){ - identifier = identifier + content[i]; - } else{ - identifier = identifier + "-" + content[i]; - } - } - var valid = true; - if(licenses[identifier]["Magnet link"] != magnet){ - valid = false; - } - if((identifier in licenses) == false){ - valid = false; - } - console.log("Valid? " + valid); - // TODO: Support more than one block and check for code outside of this block - // Can't be implemented right now since we can't edit scripts. - return valid;// TODO: this is a temporary debug solution - } else{ - console.log("Valid? false"); - } - } - // license-end regex - if(comments[i].match(/\/\/\s*@license\-end/g) != null){ - console.log("License end:"); - console.log(comments[i]) + // Contains only good Javascript + var edited_src = ""; + // Once Javascript has been "judged", remove it from here + var unedited_src = script_src; + var first = true; + var watchdog = 0; + while(true){ + if(first){ + first = false; + //console.log("input:"); + //console.log("%c"+unedited_src,"color:#550000"); + } + var matches = /^(@license)\s([\S]+)\s([\S]+$)/gm.exec(unedited_src); + if(matches == null){ + //console.log("No more matches, almost done"); + if(evaluate(unedited_src)){ + edited_src += unedited_src; } + return edited_src; + // Because we break on null, it must start at the beginning of the + // source and operate on blocks seperated by license tags + } + // operate on everything before the next match. + //console.log("Everything before the next match"); + var before = unedited_src.substr(0,matches["index"]); + //console.log(before); + if(evaluate(before)){ + edited_src += before; + } + // This should remove the substring "before" + unedited_src = unedited_src.substr(matches["index"],unedited_src.length); + // find the end tag and check if it is valid + matches_end = /^(@license-end)/gm.exec(unedited_src); + if(matches_end == null){ + //console.log("ERROR: @license with no @license-end"); + return; + } + var endtag_end_index = matches_end["index"]+matches_end[0].length; + // accept next tag if its license is good. + if(license_valid(matches)){ + edited_src = edited_src + unedited_src.substr(0,endtag_end_index); + } else{ + //console.log("Error: invalid license tag."); + } + // Remove the next tag (it will be in edited_src if it was accepted) + unedited_src = unedited_src.substr(endtag_end_index,unedited_src.length); + //console.log("New input after iteration:"); + //console.log("%c"+unedited_src,"color:red;"); + //console.log("Current output:"); + //console.log("%c"+edited_src,"color:green;"); + watchdog++; + if(watchdog > 20){ + console.log("%c Watchdog > 20.","color:reg"); + return 0; } } - //console.log("VERDICT: probably nonfree"); - //console.log("VERDICT: probably free"); } +console.log("%c"+license_read(document.getElementById("bod").innerText),"color:#550000"); /** * * Checks the whitelist in storage @@ -265,6 +314,11 @@ function get_table(url){ } xml.send(); } +/** +* Doesn't really serve a specific purpose +* +* Added because I was having async issues and needed a callback +*/ function read_w_table(table_data=false){ // Call license_read on all the document's scripts // This is done just to debug before we can implement this in a background script, diff --git a/testtag.html b/testtag.html new file mode 100644 index 0000000..01e98ba --- /dev/null +++ b/testtag.html @@ -0,0 +1,17 @@ +<!doctype html> +<html> + <head> + <title>A Page containing free JS</title> + </head> + <body> + <div id="bod" style="white-space: pre-wrap;"> +@license magnet:?xt=urn:btih:0ef1b8170b3b615170ff270def6427c317705f85&dn=lgpl-3.0.txt LGPL-3.0 +console.log("free js"); +@license-end +eval("console.log('nontrivial mystery code')"); +@license magnet:?xt=urn:btih:b8999bbaf509c08d127678643c515b9ab0836bae&dn=ISC.txt ISC +console.log("free js"); +@license-end + </div> + </body> +</html> |