wasm parsere

used to modify wasm

Ezt a szkriptet nem ajánlott közvetlenül telepíteni. Ez egy könyvtár más szkriptek számára, amik tartalmazzák a // @require https://update.sleazyfork.org/scripts/456876/1130174/wasm%20parsere.js hivatkozást.

// ==UserScript==
// @name         wasm parsere
// @version      1.0
// @description  used to modify wasm
// @author       bismuth k 
// ==/UserScript==
const OP = {"unreachable":0,"nop":1,"block":2,"loop":3,"if":4,"else":5,"end":11,"br":12,"br_if":13,"br_table":13,"return":15,"call":16,"call_indirect":17,"drop":26,"select":27,"local":{"get":32,"set":33,"tee":34},"global":{"get":35,"set":36},"i32":{"load":40,"load8_s":44,"load8_u":45,"load16_s":46,"load16_u":47,"store":54,"store8":58,"store16":59,"const":65,"eqz":69,"eq":70,"ne":71,"lt_s":72,"lt_u":73,"gt_s":74,"gt_u":75,"le_s":76,"le_u":77,"ge_s":78,"ge_u":79,"clz":103,"ctz":104,"popcnt":105,"add":106,"sub":107,"mul":108,"div_s":109,"div_u":110,"rem_s":111,"rem_u":112,"and":113,"or":114,"xor":115,"shl":116,"shr_s":117,"shr_u":118,"rotl":119,"rotr":120,"wrap_i64":167,"wrap_f32_s":168,"wrap_f32_u":169,"wrap_f64_s":170,"wrap_f64_u":171,"reinterpret_f32":188},"i64":{"load":41,"load8_s":48,"load8_u":49,"load16_s":50,"load16_u":51,"load32_s":52,"load32_u":53,"store":55,"store8":60,"store16":61,"store32":62,"const":66,"eqz":80,"eq":81,"ne":82,"lt_s":83,"lt_u":84,"gt_s":85,"gt_u":86,"le_s":87,"le_u":88,"ge_s":89,"ge_u":90,"clz":121,"ctz":122,"popcnt":123,"add":124,"sub":125,"mul":126,"div_s":127,"div_u":128,"rem_s":129,"rem_u":130,"and":131,"or":132,"xor":133,"shl":134,"shr_s":135,"shr_u":136,"rotl":137,"rotr":138,"extend_i32_s":172,"extend_i32_u":173,"trunc_f32_s":174,"trunc_f32_u":175,"trunc_f64_s":176,"trunc_f64_u":177,"reinterpret_f64":189},"f32":{"load":42,"store":56,"const":67,"eq":75,"ne":76,"lt":77,"gt":78,"le":79,"ge":80,"abd":139,"neg":140,"ceil":141,"floor":142,"trunc":143,"nearest":144,"sqrt":145,"add":146,"sub":147,"mul":148,"div":149,"min":150,"max":151,"copysign":152,"convert_i32_s":178,"convert_i32_u":179,"convert_i64_s":180,"convert_i64_u":181,"demote_f64":182,"reinterpret_i32":190},"f64":{"load":43,"store":57,"const":68,"eq":97,"ne":98,"lt":99,"gt":100,"le":101,"ge":102,"abd":153,"neg":154,"ceil":155,"floor":156,"trunc":157,"nearest":158,"sqrt":159,"add":160,"sub":161,"mul":162,"div":163,"min":164,"max":165,"copysign":166,"convert_i32_s":183,"convert_i32_u":184,"convert_i64_s":185,"convert_i64_u":186,"promote_f32":187,"reinterpret_i64":191},"memory":{"size":63,"grow":64}};
class WASMSection {
    constructor(desc,length) {
        this.section = desc;
        this.body = new Array(length);
    }
}
class WASMParser {
    constructor(bin) {
        this.lexer = new Reader(new Uint8Array(bin));
        this.sections = new Array(13);
        this.adjustImports = 0;
        this.importFuncCount = 0;
        this.parseWASM();
    }
    read(bin) { this.lexer.packet = new Uint8Array(bin) }
    regex(match, allOccurences) {
        let ret = [], rets = [];
        search: for (let n = this.lexer.index; n < this.lexer.packet.length - match.length; n++) {
            this.lexer.index = n;
            ret = [];
            for (let p = 0; p < match.length; p++) {
                if (match[p] === '*') this.lexer.vu();
                else if (match[p] === '+') ret.push(this.lexer.vu());
                else if (this.lexer.u8() !== match[p]) continue search;
            }
            if (allOccurences) rets.push(ret);
            else {
                this.lexer.index = n;
                return ret;
            }
        }
        return rets.length? rets: false;
    }
    loadFunc(index) {
        this.lexer.set(this.sections[10].body[index - this.importFuncCount]);
        const localLength = this.lexer.vu();
        for (let n = 0; n < localLength; n++) {
            this.lexer.vu();
            this.lexer.u8();
        }
        return;
    }
    set(index, val) {
        this.sections[10].body[index - this.importFuncCount] = val;
    }
    getAdjusted(index) {
        if (index < this.importFuncCount) return index;
        return index + this.adjustImports;
    }
    addImportEntry(options) {
        const map = ['f64','f32','i64','i32'];
        switch(options.type) {
            case 'func':
                this.sections[2].body.push({
                    name: options.name,
                    type: "func",
                    index: this.sections[1].body.length
                });
                this.sections[1].body.push({
                    param: options.params,
                    return: options.returns
                });
                this.adjustImports++;
                return this.sections[2].body.length - 1;
                break;
            default:
                throw new Error('oops, not supported yet');
                break;
        }
    }
    reindex() {
        let section = this.sections[10].body;
        let length = section.length;
        for (let n = 0; n < length; n++) this.sections[10].body[n] = this.parseFunction(section[n]);
        section = this.sections[9].body;
        length = section.length;
        for (let n = 0; n < length; n++) {
            const l = section[n].funcs.length;
            for (let p = 0; p < l; p++) this.sections[9].body[n].funcs[p] = this.getAdjusted(section[n].funcs[p]);
        }
        section = this.sections[7].body;
        length = section.length;
        for (let n = 0; n < length; n++) this.sections[7].body[n].index = this.getAdjusted(section[n].index);
        this.adjustImports = 0;
    }
    compile() {
        const bin = [0, 97, 115, 109, 1, 0, 0, 0];
        for (let n = 0; n < 12; n++) {
            if (!this.sections[n]) continue;
            const section = this[`compileSection0x${n.toString(16)}`]();
            bin.push(n);
            bin.push(...Writer.vu(section.length));
            for (const byte of section) bin.push(byte);
        }
        return new Uint8Array(bin);
    }
    compileSection0x1() {
        const map = ['f64','f32','i64','i32'];
        const section = this.sections[1].body;
        const length = section.length;
        const bin = Writer.vu(length);
        for (let n = 0; n < length; n++) {
            bin.push(0x60);
            bin.push(...Writer.vu(section[n].param.length));
            for (const param of section[n].param) bin.push(map.indexOf(param) + 0x7C);
            bin.push(...Writer.vu(section[n].return.length));
            for (const param of section[n].return) bin.push(map.indexOf(param) + 0x7C);
        }
        return bin;
    }
    compileSection0x2() {
        const map = ['func','table','mem','global'];
        const section = this.sections[2].body;
        const length = section.length;
        const bin = Writer.vu(length);
        for (let n = 0; n < length; n++) {
            const nameSplit = section[n].name.split('.');
            for (const part of nameSplit) bin.push(...Writer.stringLEN(part));
            bin.push(map.indexOf(section[n].type));
            bin.push(...Writer.vu(section[n].index));
            //console.log(bin);
        }
        return bin;
    }
    compileSection0x3() {
        const section = this.sections[3].body;
        const length = section.length;
        const bin = Writer.vu(length);
        for (let n = 0; n < length; n++) bin.push(...Writer.vu(section[n]));
        return bin;
    }
    compileSection0x4() {
        const section = this.sections[4].body;
        const length = section.length;
        const bin = Writer.vu(length);
        for (let n = 0; n < length; n++) for (let p = 0; p < 4; p++) bin.push(...Writer.vu(section[n][p]));
        return bin;
    }
    compileSection0x5() {
        const section = this.sections[5].body;
        const length = section.length;
        const bin = Writer.vu(length);
        for (let n = 0; n < length; n++) {
            bin.push(...Writer.vu(section[n].type));
            bin.push(...Writer.vu(section[n].limit[0]));
            bin.push(...Writer.vu(section[n].limit[1]));
        }
        return bin;
    }
    compileSection0x6() {
        const map = ['f64','f32','i64','i32'];
        const section = this.sections[6].body;
        const length = section.length;
        const bin = Writer.vu(length);
        for (let n = 0; n < length; n++) {
            bin.push(map.indexOf(section[n].type) + 0x7C);
            bin.push(section[n].mutable);
            for (const expr of section[n].expr) bin.push(...Writer.vu(expr));
            bin.push(11);
        }
        return bin;
    }
    compileSection0x7() {
        const map = ['func','table','mem','global'];
        const section = this.sections[7].body;
        const length = section.length;
        const bin = Writer.vu(length);
        for (let n = 0; n < length; n++) {
            bin.push(...Writer.stringLEN(section[n].name));
            bin.push(map.indexOf(section[n].type));
            bin.push(...Writer.vu(section[n].index));
        }
        return bin;
    }
    compileSection0x8() {
        const section = this.sections[8].body;
        const length = 1;
        const bin = [1];
        bin.push(...Writer.vu(section));
        return bin;
    }
    compileSection0x9() {
        const section = this.sections[9].body;
        const length = section.length;
        const bin = Writer.vu(length);
        for (let n = 0; n < length; n++) {
            bin.push(section[n].type, section[n].expr[0]);
            bin.push(...Writer.vi(section[n].expr[1]),11);
            bin.push(...Writer.vu(section[n].funcs.length));
            for (const funcIdx of section[n].funcs) bin.push(...Writer.vu(funcIdx));
        }
        return bin;
    }
    compileSection0xa() {
        const section = this.sections[10].body;
        const length = section.length;
        const bin = Writer.vu(length);
        for (let n = 0; n < length; n++) {
            //section[n] = this.parseFunction(section[n]);
            bin.push(...Writer.vu(section[n].length));
            for (const byte of section[n]) bin.push(byte);
        }
        return bin;
    }
    compileSection0xb() {
        const section = this.sections[11].body;
        const length = section.length;
        const bin = Writer.vu(length);
        for (let n = 0; n < length; n++) {
            bin.push(section[n].type,section[n].expr[0]);
            bin.push(...Writer.vi(section[n].expr[1]),11);
            bin.push(...Writer.vu(section[n].contents.length));
            bin.push(...section[n].contents);
        }
        return bin;
    }
    parseWASM() {
        this.lexer.index = 8;
        while (this.lexer.has()) {
            const id = this.lexer.u8();
            if (id > 12) return;
            this[`parseSection0x${id.toString(16)}`]();
        }
        this.importFuncCount = this.sections[2].body.filter(({type}) => type === 'func').length;
    }
    parseSection0x1() {
        const map = ['f64','f32','i64','i32'];
        const rawLength = this.lexer.vu();
        const section = new WASMSection('functypes', this.lexer.vu());
        for (let n = 0; n < section.body.length; n++) {
            const type = { param: [], return: [] }
            if (this.lexer.u8() !== 0x60) break;
            let len = this.lexer.vu();
            for (let n = 0; n < len; n++) type.param.push(map[this.lexer.u8()-0x7C]);
            len = this.lexer.vu();
            for (let n = 0; n < len; n++) type.return.push(map[this.lexer.u8()-0x7C]);
            section.body[n] = type;
        }
        return (this.sections[1] = section);
    }
    parseSection0x2() {
        const map = ['func','table','mem','global'];
        this.lexer.vu();
        const section = new WASMSection('imports', this.lexer.vu());
        for (let n = 0; n < section.body.length; n++) section.body[n] = { name: this.lexer.stringLEN() + '.' + this.lexer.stringLEN(), type: map[this.lexer.u8()], index: this.lexer.vu() };
        return (this.sections[2] = section);
    }
    parseSection0x3() {
        this.lexer.vu();
        const section = new WASMSection('functions', this.lexer.vu());
        for (let n = 0; n < section.body.length; n++) section.body[n] = this.lexer.vu();
        return (this.sections[3] = section);
    }
    parseSection0x4() {
        this.lexer.vu();
        const section = new WASMSection('tables', this.lexer.vu());
        for (let n = 0; n < section.body.length; n++) section.body[n] = [this.lexer.vu(), this.lexer.vu(), this.lexer.vu(), this.lexer.vu()]; //incomplete
        return (this.sections[4] = section);
    }
    parseSection0x5() {
        this.lexer.vu();
        const section = new WASMSection('mem', this.lexer.vu());
        for (let n = 0; n < section.body.length; n++) section.body[n] = { type: this.lexer.vu(), limit: [this.lexer.vu(), this.lexer.vu()] }
        return (this.sections[5] = section);
    }
    parseSection0x6() {
        const map = ['f64','f32','i64','i32'];
        this.lexer.vu();
        const section = new WASMSection('globals', this.lexer.vu());
        for (let n = 0; n < section.body.length; n++) {
            section.body[n] = { type: map[this.lexer.u8()-0x7C], mutable: this.lexer.u8(), expr: [] }
            section.body[n].expr.push(this.lexer.ru8());
            switch(this.lexer.u8()) {
                case OP.i32.const:
                case OP.i64.const:
                    section.body[n].expr.push(this.lexer.vu());
                    break;
                case OP.f32.const:
                    section.body[n].expr.push(this.f32());
                    break;
                case OP.f64.const:
                    section.body[n].expr.push(this.f64());
                    break;
            }
            this.lexer.u8();
        }
        return (this.sections[6] = section);
    }
    parseSection0x7() {
        const map = ['func','table','mem','global'];
        this.lexer.vu();
        const section = new WASMSection('exports', this.lexer.vu());
        for (let n = 0; n < section.body.length; n++) {
            const name = this.lexer.stringLEN();
            const type = map[this.lexer.u8()];
            const index = this.lexer.vu();
            section.body[n] = { name, type, index };
        }
        return (this.sections[7] = section);
    }
    parseSection0x8() {
        this.lexer.vu();
        const section = new WASMSection('start', this.lexer.vu());
        section.body = this.vu();
        return (this.sections[8] = section);
    }
    parseSection0x9() {
        this.lexer.vu();
        const section = new WASMSection('elements', this.lexer.vu());
        for (let n = 0; n < section.body.length; n++) {
            section.body[n] = { type: this.lexer.u8() }; //NEED TO ACCOUNT FOR DIFFERENT TYPES
            section.body[n].expr = [this.lexer.u8(),this.lexer.vu()];
            this.lexer.u8();
            const repeat = this.lexer.vu();
            section.body[n].funcs = [];
            for (let p = 0; p < repeat; p++) section.body[n].funcs.push(this.lexer.vu());
        }
        return (this.sections[9] = section);
    }
    parseSection0xa() {
        this.lexer.vu();
        const section = new WASMSection('code', this.lexer.vu());
        for (let n = 0; n < section.body.length; n++) {
            const len = this.lexer.vu();
            section.body[n] = this.lexer.packet.slice(this.lexer.index, this.lexer.index += len);
        }
        return (this.sections[10] = section);
    }
    parseSection0xb() {
        this.lexer.vu();
        const t = this.lexer.index;

        const section = new WASMSection('data', this.lexer.vu());
        for (let n = 0; n < section.body.length; n++) {
            section.body[n] = { type: this.lexer.u8(), expr: [this.lexer.u8(),this.lexer.vu()] };
            this.lexer.u8();
            const len = this.lexer.vu();
            section.body[n].contents = this.lexer.packet.slice(this.lexer.index, this.lexer.index += len);
        }
        return (this.sections[11] = section);
    }
    parseFunction(func) {
        this.lexer.set(func);
        const localLength = this.lexer.vu();
        let len, before;
        for (let n = 0; n < localLength; n++) {
            this.lexer.vu();
            this.lexer.u8();
        }
        while(this.lexer.has()) {
            let op;
            switch(op = this.lexer.u8()) {
                case OP.block: case OP.loop: case OP.if:
                case OP.memory.size: case OP.memory.grow:
                    this.lexer.u8();
                    break;
                case OP.br: case OP.br_if:
                case OP.local.get: case OP.local.set: case OP.local.tee:
                case OP.i32.const: case OP.i64.const:
                    this.lexer.vu();
                    break;
                case OP.f32.const:
                    this.lexer.f32();
                    break;
                case OP.f64.const:
                    this.lexer.f64();
                    break;
                case OP.global.get: case OP.global.set:
                    this.lexer.vu();
                    break; //adjust global index later
                case OP.i32.load: case OP.i32.load8_s: case OP.i32.load8_u: case OP.i32.load16_s: case OP.i32.load16_u:
                case OP.i64.load: case OP.i64.load8_s: case OP.i64.load8_u: case OP.i64.load16_s: case OP.i64.load16_u: case OP.i64.load32_s: case OP.i64.load32_u:
                case OP.f32.load:
                case OP.f64.load:
                case OP.i32.store: case OP.i32.store8: case OP.i32.store16:
                case OP.i64.store: case OP.i64.store8: case OP.i64.store16: case OP.i64.store32:
                case OP.f32.store:
                case OP.f64.store:
                    this.lexer.vu();
                    this.lexer.vu();
                    break;
                case OP.call_indirect:
                    this.lexer.vu();
                    this.lexer.u8();
                    break;
                case OP.br_table:
                    len = this.lexer.vu();
                    for (let n = 0; n < len+1; n++) this.lexer.vu();
                    break;
                case OP.call:
                    len = this.lexer.index;
                    before = this.lexer.vu();
                    this.lexer.index = len;
                    this.lexer.replaceVu(this.getAdjusted(before));
                    break;
                default:
                    if (op > 255) throw new Error('oops, you did something wrong');
                    break;
            }
        }
        return this.lexer.packet;
    }
}
class Writer {
    static vu(num) {
        const ret = [];
        while (num >= 128) {
            ret.push((num & 127) | 128);
            num >>= 7;
        }
        ret.push(num);
        return ret;
    }
    static vi(num) {
        const ret = [];
        while (num >= 128) {
            ret.push((num & 127) | 128);
            num >>= 7;
        }
        if(num < 0x40) ret.push(num);
        else {
            ret.push(num | 0x80);
            ret.push(num<0?1:0);
        }
        return ret;
    }
    static stringLEN(str) {
        str = new TextEncoder().encode(str);
        if (str.length > 127) throw new Error('Unsupported string length: don\'t use a string that long (max 127 byte length)');
        return [str.length, ...str];
    }
}
class Reader {
    constructor(packet) {
        this.packet = packet;
        this.index = 0;
        const buffer = new ArrayBuffer(8);
        this._u8 = new Uint8Array(buffer);
        this._f32 = new Float32Array(buffer);
        this._f64 = new Float64Array(buffer);
    }
    inject(code) {
        const newBuf = new Uint8Array(code.length + this.packet.length);
        newBuf.set(this.packet.slice(0,this.index),0);
        newBuf.set(code,this.index);
        newBuf.set(this.packet.slice(this.index),(this.index+code.length));
        return (this.packet = newBuf);
    }
    replaceVu(replace) {
        const before = this.index, old = this.vu(), now = this.index;
        replace = Writer.vu(replace);
        if (replace.length === now - before) this.packet.set(replace, before);
        else {
            const newBuf = new Uint8Array(this.packet.length-now+before+replace.length);
            newBuf.set(this.packet.slice(0,before),0);
            newBuf.set(replace,before);
            newBuf.set(this.packet.slice(now),(this.index=before+replace.length));
            this.packet = newBuf;
        }
    }
    has() { return this.index < this.packet.length }
    set(packet) {
        this.packet = packet;
        this.index = 0;
    }
    ru8() { return this.packet[this.index] }
    u8() { return this.packet[this.index++] }
    f32() {
        this._u8.set(this.packet.slice(this.index, this.index += 4));
        return this._f32[0];
    }
    f64() {
        this._u8.set(this.packet.slice(this.index, this.index += 8));
        return this._f64[0];
    }
    vu() {
        let out = 0, at = 0;
        while (this.packet[this.index] & 0x80) {
            out |= (this.u8() & 0x7f) << at;
            at += 7;
        }
        out |= this.u8() << at;
        return out;
    }
    stringLEN() {
        const len = this.u8();
        const ret = new TextDecoder().decode(this.packet.slice(this.index, this.index += len));
        return ret;
    }
}