/*! otorp (C) 2013-present SheetJS -- http://sheetjs.com */ import { u8indexOf, u8str, u8_to_dataview } from "../../../modules/src/util"; import { parse_macho } from "./macho"; import { Descriptor, parse_FileDescriptor, write_FileDescriptor } from './descriptor'; interface OtorpEntry { name: string; proto: string; } export { OtorpEntry }; /** Find and stringify all relevant protobuf defs */ function otorp(buf: Uint8Array, builtins = false): OtorpEntry[] { var res = proto_offsets(buf); var registry: {[key: string]: Descriptor} = {}; var names: Set<string> = new Set(); var out: OtorpEntry[] = []; res.forEach((r, i) => { if(!builtins && r[1].startsWith("google/protobuf/")) return; var b = buf.slice(r[0], i < res.length - 1 ? res[i+1][0] : buf.length); var pb = parse_FileDescriptorProto(b/*, r[1]*/); names.add(r[1]); registry[r[1]] = pb; }); names.forEach(name => { /* ensure partial ordering by dependencies */ names.delete(name); var pb = registry[name]; var doit = (pb.dependency||[]).every((d: string) => !names.has(d)); if(!doit) { names.add(name); return; } var dups = res.filter(r => r[1] == name); if(dups.length == 1) return out.push({ name, proto: write_FileDescriptor(pb) }); /* in a fat binary, compare the defs for x86_64/aarch64 */ var pbs = dups.map(r => { var i = res.indexOf(r); var b = buf.slice(r[0], i < res.length - 1 ? res[i+1][0] : buf.length); var pb = parse_FileDescriptorProto(b/*, r[1]*/); return write_FileDescriptor(pb); }); for(var l = 1; l < pbs.length; ++l) if(pbs[l] != pbs[0]) throw new Error(`Conflicting definitions for ${name} at offsets 0x${dups[0][0].toString(16)} and 0x${dups[l][0].toString(16)}`); return out.push({ name, proto: pbs[0] }); }); return out; } export default otorp; /** Determine if an address is being referenced */ var is_referenced = (buf: Uint8Array, pos: number): boolean => { var dv = u8_to_dataview(buf); /* Search for LEA reference (x86) */ for(var leaddr = 0; leaddr > -1 && leaddr < pos; leaddr = u8indexOf(buf, 0x8D, leaddr + 1)) if(dv.getUint32(leaddr + 2, true) == pos - leaddr - 6) return true; /* Search for absolute reference to address */ try { var headers = parse_macho(buf); for(var i = 0; i < headers.length; ++i) { if(pos < headers[i].offset || pos > headers[i].offset + headers[i].size) continue; var b = headers[i].data; var p = pos - headers[i].offset; var ref = new Uint8Array([0,0,0,0,0,0,0,0]); var dv = u8_to_dataview(ref); dv.setInt32(0, p, true); if(u8indexOf(b, ref, 0) > 0) return true; ref[4] = 0x01; if(u8indexOf(b, ref, 0) > 0) return true; } } catch(e) {} return false; }; type OffsetList = Array<[number, string, number, number]>; /** Generate a list of potential starting points */ var proto_offsets = (buf: Uint8Array): OffsetList => { var meta = parse_macho(buf); var out: OffsetList = []; var off = 0; /* note: this loop only works for names < 128 chars */ search: while((off = u8indexOf(buf, ".proto", off + 1)) > -1) { var pos = off; off += 6; while(off - pos < 256 && buf[pos] != off - pos - 1) { if(buf[pos] > 0x7F || buf[pos] < 0x20) continue search; --pos; } if(off - pos > 250) continue; var name = u8str(buf.slice(pos + 1, off)); if(buf[--pos] != 0x0A) continue; if(!is_referenced(buf, pos)) { console.error(`Reference to ${name} not found`); continue; } var bin = meta.find(m => m.offset <= pos && m.offset + m.size >= pos); out.push([pos, name, bin?.type || -1, bin?.subtype || -1]); } return out; }; /** Parse a descriptor that starts with the first byte of the supplied buffer */ var parse_FileDescriptorProto = (buf: Uint8Array): Descriptor => { var l = buf.length; while(l > 0) try { var b = buf.slice(0,l); var o = parse_FileDescriptor(b); return o; } catch(e) { var m = e.message.match(/at offset (\d+)/); if(m && parseInt(m[1], 10) < buf.length) l = parseInt(m[1], 10) - 1; else --l; } throw new RangeError("no protobuf message in range"); };