lapo.it
1#!/usr/bin/env node
2
3// usage:
4// ./dumpASN1.js filename
5// ./dumpASN1.js data:base64,MDMCAQFjLgQACgEACgEAAgEAAgEAAQEAoA+jDQQFTnRWZXIEBAEAAAAwCgQITmV0bG9nb24===
6
7import * as fs from 'node:fs';
8import { Base64 } from './base64.js';
9import { ASN1 } from './asn1.js';
10import { Defs } from './defs.js';
11
12const
13 colYellow = '\x1b[33m',
14 colBlue = '\x1b[34m',
15 colReset = '\x1b[0m',
16 reDataURI = /^data:(?:[a-z-]+[/][a-z.+-]+;)?base64,([A-Za-z0-9+/=\s]+)$/;
17
18function print(value, indent) {
19 if (indent === undefined) indent = '';
20 const def = value.def;
21 let name = '';
22 if (def?.type) {
23 if (def.id) name += colBlue + def.id + colReset;
24 if (typeof def.type == 'object' && def.name) name = (name ? name + ' ' : '') + def.name;
25 if (def.mismatch) name = (name ? name + ' ' : '') + '[?]';
26 if (name) name += ' ';
27 }
28 let s = indent + name + colYellow + value.typeName() + colReset + ' @' + value.stream.pos;
29 if (value.length >= 0)
30 s += '+';
31 s += value.length;
32 if (value.tag.tagConstructed)
33 s += ' (constructed)';
34 else if ((value.tag.isUniversal() && ((value.tag.tagNumber == 0x03) || (value.tag.tagNumber == 0x04))) && (value.sub !== null))
35 s += ' (encapsulates)';
36 let content = value.content();
37 if (content)
38 s += ': ' + content.replace(/\n/g, '|');
39 s += '\n';
40 if (value.sub !== null) {
41 indent += ' ';
42 for (const subval of value.sub)
43 s += print(subval, indent);
44 }
45 return s;
46}
47
48const filename = process.argv[2];
49const match = reDataURI.exec(filename);
50let content = match
51 ? Buffer.from(match[1])
52 : fs.readFileSync(filename);
53try { // try PEM first
54 content = Base64.unarmor(content);
55} catch (e) { // try DER/BER then
56}
57let result = ASN1.decode(content);
58content = null;
59const t0 = performance.now();
60if (process.argv.length == 5) {
61 Defs.match(result, Defs.moduleAndType(Defs.RFC[process.argv[3]], process.argv[4]));
62} else {
63 const types = Defs.commonTypes
64 .map(type => {
65 const stats = Defs.match(result, type);
66 return { type, match: stats.recognized / stats.total };
67 })
68 .sort((a, b) => b.match - a.match);
69 const t1 = performance.now();
70 console.log('Parsed in ' + (t1 - t0).toFixed(2) + ' ms; possible types:');
71 for (const t of types)
72 console.log((t.match * 100).toFixed(2).padStart(6) + '% ' + t.type.description);
73 Defs.match(result, types[0].type);
74 // const stats = Defs.match(result, types[0].type);
75 // console.log('Stats:', stats);
76 console.log('Parsed as:', result.def);
77 // const type = searchType(process.argv[2]);
78 // const stats = applyDef(result, type);
79}
80console.log(print(result));
81// console.log('Stats:', (stats.recognized * 100 / stats.total).toFixed(2) + '%');
82// // print(result, searchType(process.argv[2]), stats);
83// // console.log('Defs:', stats.defs);