132 lines
3.0 KiB
JavaScript
132 lines
3.0 KiB
JavaScript
'use strict';
|
|
|
|
var ASN1 = module.exports;
|
|
var Enc = require('@root/encoding/hex');
|
|
|
|
//
|
|
// Packer
|
|
//
|
|
|
|
// Almost every ASN.1 type that's important for CSR
|
|
// can be represented generically with only a few rules.
|
|
function Any(/*type, hexstrings...*/) {
|
|
var args = Array.prototype.slice.call(arguments);
|
|
var typ = args.shift();
|
|
var str = args
|
|
.join('')
|
|
.replace(/\s+/g, '')
|
|
.toLowerCase();
|
|
var len = str.length / 2;
|
|
var lenlen = 0;
|
|
var hex = typ;
|
|
if ('number' === typeof hex) {
|
|
hex = Enc.numToHex(hex);
|
|
}
|
|
|
|
// We can't have an odd number of hex chars
|
|
if (len !== Math.round(len)) {
|
|
throw new Error('invalid hex');
|
|
}
|
|
|
|
// The first byte of any ASN.1 sequence is the type (Sequence, Integer, etc)
|
|
// The second byte is either the size of the value, or the size of its size
|
|
|
|
// 1. If the second byte is < 0x80 (128) it is considered the size
|
|
// 2. If it is > 0x80 then it describes the number of bytes of the size
|
|
// ex: 0x82 means the next 2 bytes describe the size of the value
|
|
// 3. The special case of exactly 0x80 is "indefinite" length (to end-of-file)
|
|
|
|
if (len > 127) {
|
|
lenlen += 1;
|
|
while (len > 255) {
|
|
lenlen += 1;
|
|
len = len >> 8;
|
|
}
|
|
}
|
|
|
|
if (lenlen) {
|
|
hex += Enc.numToHex(0x80 + lenlen);
|
|
}
|
|
return hex + Enc.numToHex(str.length / 2) + str;
|
|
}
|
|
ASN1.Any = Any;
|
|
|
|
// The Integer type has some special rules
|
|
ASN1.UInt = function UINT() {
|
|
var str = Array.prototype.slice.call(arguments).join('');
|
|
var first = parseInt(str.slice(0, 2), 16);
|
|
|
|
// If the first byte is 0x80 or greater, the number is considered negative
|
|
// Therefore we add a '00' prefix if the 0x80 bit is set
|
|
if (0x80 & first) {
|
|
str = '00' + str;
|
|
}
|
|
|
|
return Any('02', str);
|
|
};
|
|
|
|
// The Bit String type also has a special rule
|
|
ASN1.BitStr = function BITSTR() {
|
|
var str = Array.prototype.slice.call(arguments).join('');
|
|
// '00' is a mask of how many bits of the next byte to ignore
|
|
return Any('03', '00' + str);
|
|
};
|
|
|
|
ASN1._toArray = function toArray(next, opts) {
|
|
var typ = opts.json ? Enc.numToHex(next.type) : next.type;
|
|
var val = next.value;
|
|
if (val) {
|
|
if ('string' !== typeof val && opts.json) {
|
|
val = Enc.bufToHex(val);
|
|
}
|
|
return [typ, val];
|
|
}
|
|
return [
|
|
typ,
|
|
next.children.map(function(child) {
|
|
return toArray(child, opts);
|
|
})
|
|
];
|
|
};
|
|
|
|
ASN1._pack = function(arr) {
|
|
var typ = arr[0];
|
|
if ('number' === typeof arr[0]) {
|
|
typ = Enc.numToHex(arr[0]);
|
|
}
|
|
var str = '';
|
|
if (Array.isArray(arr[1])) {
|
|
arr[1].forEach(function(a) {
|
|
str += ASN1._pack(a);
|
|
});
|
|
} else if ('string' === typeof arr[1]) {
|
|
str = arr[1];
|
|
} else if (arr[1].byteLength) {
|
|
str = Enc.bufToHex(arr[1]);
|
|
} else {
|
|
throw new Error('unexpected array');
|
|
}
|
|
if ('03' === typ) {
|
|
return ASN1.BitStr(str);
|
|
} else if ('02' === typ) {
|
|
return ASN1.UInt(str);
|
|
} else {
|
|
return Any(typ, str);
|
|
}
|
|
};
|
|
|
|
// TODO should this return a buffer?
|
|
ASN1.pack = function(asn1, opts) {
|
|
if (!opts) {
|
|
opts = {};
|
|
}
|
|
if (!Array.isArray(asn1)) {
|
|
asn1 = ASN1._toArray(asn1, { json: true });
|
|
}
|
|
var result = ASN1._pack(asn1);
|
|
if (opts.json) {
|
|
return result;
|
|
}
|
|
return Enc.hexToBuf(result);
|
|
};
|