diff options
Diffstat (limited to 'node_modules/asn1.js/lib/asn1/decoders/der.js')
-rw-r--r-- | node_modules/asn1.js/lib/asn1/decoders/der.js | 324 |
1 files changed, 324 insertions, 0 deletions
diff --git a/node_modules/asn1.js/lib/asn1/decoders/der.js b/node_modules/asn1.js/lib/asn1/decoders/der.js new file mode 100644 index 000000000..79a60acc2 --- /dev/null +++ b/node_modules/asn1.js/lib/asn1/decoders/der.js @@ -0,0 +1,324 @@ +var inherits = require('inherits'); + +var asn1 = require('../../asn1'); +var base = asn1.base; +var bignum = asn1.bignum; + +// Import DER constants +var der = asn1.constants.der; + +function DERDecoder(entity) { + this.enc = 'der'; + this.name = entity.name; + this.entity = entity; + + // Construct base tree + this.tree = new DERNode(); + this.tree._init(entity.body); +}; +module.exports = DERDecoder; + +DERDecoder.prototype.decode = function decode(data, options) { + if (!(data instanceof base.DecoderBuffer)) + data = new base.DecoderBuffer(data, options); + + return this.tree._decode(data, options); +}; + +// Tree methods + +function DERNode(parent) { + base.Node.call(this, 'der', parent); +} +inherits(DERNode, base.Node); + +DERNode.prototype._peekTag = function peekTag(buffer, tag, any) { + if (buffer.isEmpty()) + return false; + + var state = buffer.save(); + var decodedTag = derDecodeTag(buffer, 'Failed to peek tag: "' + tag + '"'); + if (buffer.isError(decodedTag)) + return decodedTag; + + buffer.restore(state); + + return decodedTag.tag === tag || decodedTag.tagStr === tag || + (decodedTag.tagStr + 'of') === tag || any; +}; + +DERNode.prototype._decodeTag = function decodeTag(buffer, tag, any) { + var decodedTag = derDecodeTag(buffer, + 'Failed to decode tag of "' + tag + '"'); + if (buffer.isError(decodedTag)) + return decodedTag; + + var len = derDecodeLen(buffer, + decodedTag.primitive, + 'Failed to get length of "' + tag + '"'); + + // Failure + if (buffer.isError(len)) + return len; + + if (!any && + decodedTag.tag !== tag && + decodedTag.tagStr !== tag && + decodedTag.tagStr + 'of' !== tag) { + return buffer.error('Failed to match tag: "' + tag + '"'); + } + + if (decodedTag.primitive || len !== null) + return buffer.skip(len, 'Failed to match body of: "' + tag + '"'); + + // Indefinite length... find END tag + var state = buffer.save(); + var res = this._skipUntilEnd( + buffer, + 'Failed to skip indefinite length body: "' + this.tag + '"'); + if (buffer.isError(res)) + return res; + + len = buffer.offset - state.offset; + buffer.restore(state); + return buffer.skip(len, 'Failed to match body of: "' + tag + '"'); +}; + +DERNode.prototype._skipUntilEnd = function skipUntilEnd(buffer, fail) { + while (true) { + var tag = derDecodeTag(buffer, fail); + if (buffer.isError(tag)) + return tag; + var len = derDecodeLen(buffer, tag.primitive, fail); + if (buffer.isError(len)) + return len; + + var res; + if (tag.primitive || len !== null) + res = buffer.skip(len) + else + res = this._skipUntilEnd(buffer, fail); + + // Failure + if (buffer.isError(res)) + return res; + + if (tag.tagStr === 'end') + break; + } +}; + +DERNode.prototype._decodeList = function decodeList(buffer, tag, decoder, + options) { + var result = []; + while (!buffer.isEmpty()) { + var possibleEnd = this._peekTag(buffer, 'end'); + if (buffer.isError(possibleEnd)) + return possibleEnd; + + var res = decoder.decode(buffer, 'der', options); + if (buffer.isError(res) && possibleEnd) + break; + result.push(res); + } + return result; +}; + +DERNode.prototype._decodeStr = function decodeStr(buffer, tag) { + if (tag === 'bitstr') { + var unused = buffer.readUInt8(); + if (buffer.isError(unused)) + return unused; + return { unused: unused, data: buffer.raw() }; + } else if (tag === 'bmpstr') { + var raw = buffer.raw(); + if (raw.length % 2 === 1) + return buffer.error('Decoding of string type: bmpstr length mismatch'); + + var str = ''; + for (var i = 0; i < raw.length / 2; i++) { + str += String.fromCharCode(raw.readUInt16BE(i * 2)); + } + return str; + } else if (tag === 'numstr') { + var numstr = buffer.raw().toString('ascii'); + if (!this._isNumstr(numstr)) { + return buffer.error('Decoding of string type: ' + + 'numstr unsupported characters'); + } + return numstr; + } else if (tag === 'octstr') { + return buffer.raw(); + } else if (tag === 'objDesc') { + return buffer.raw(); + } else if (tag === 'printstr') { + var printstr = buffer.raw().toString('ascii'); + if (!this._isPrintstr(printstr)) { + return buffer.error('Decoding of string type: ' + + 'printstr unsupported characters'); + } + return printstr; + } else if (/str$/.test(tag)) { + return buffer.raw().toString(); + } else { + return buffer.error('Decoding of string type: ' + tag + ' unsupported'); + } +}; + +DERNode.prototype._decodeObjid = function decodeObjid(buffer, values, relative) { + var result; + var identifiers = []; + var ident = 0; + while (!buffer.isEmpty()) { + var subident = buffer.readUInt8(); + ident <<= 7; + ident |= subident & 0x7f; + if ((subident & 0x80) === 0) { + identifiers.push(ident); + ident = 0; + } + } + if (subident & 0x80) + identifiers.push(ident); + + var first = (identifiers[0] / 40) | 0; + var second = identifiers[0] % 40; + + if (relative) + result = identifiers; + else + result = [first, second].concat(identifiers.slice(1)); + + if (values) { + var tmp = values[result.join(' ')]; + if (tmp === undefined) + tmp = values[result.join('.')]; + if (tmp !== undefined) + result = tmp; + } + + return result; +}; + +DERNode.prototype._decodeTime = function decodeTime(buffer, tag) { + var str = buffer.raw().toString(); + if (tag === 'gentime') { + var year = str.slice(0, 4) | 0; + var mon = str.slice(4, 6) | 0; + var day = str.slice(6, 8) | 0; + var hour = str.slice(8, 10) | 0; + var min = str.slice(10, 12) | 0; + var sec = str.slice(12, 14) | 0; + } else if (tag === 'utctime') { + var year = str.slice(0, 2) | 0; + var mon = str.slice(2, 4) | 0; + var day = str.slice(4, 6) | 0; + var hour = str.slice(6, 8) | 0; + var min = str.slice(8, 10) | 0; + var sec = str.slice(10, 12) | 0; + if (year < 70) + year = 2000 + year; + else + year = 1900 + year; + } else { + return buffer.error('Decoding ' + tag + ' time is not supported yet'); + } + + return Date.UTC(year, mon - 1, day, hour, min, sec, 0); +}; + +DERNode.prototype._decodeNull = function decodeNull(buffer) { + return null; +}; + +DERNode.prototype._decodeBool = function decodeBool(buffer) { + var res = buffer.readUInt8(); + if (buffer.isError(res)) + return res; + else + return res !== 0; +}; + +DERNode.prototype._decodeInt = function decodeInt(buffer, values) { + // Bigint, return as it is (assume big endian) + var raw = buffer.raw(); + var res = new bignum(raw); + + if (values) + res = values[res.toString(10)] || res; + + return res; +}; + +DERNode.prototype._use = function use(entity, obj) { + if (typeof entity === 'function') + entity = entity(obj); + return entity._getDecoder('der').tree; +}; + +// Utility methods + +function derDecodeTag(buf, fail) { + var tag = buf.readUInt8(fail); + if (buf.isError(tag)) + return tag; + + var cls = der.tagClass[tag >> 6]; + var primitive = (tag & 0x20) === 0; + + // Multi-octet tag - load + if ((tag & 0x1f) === 0x1f) { + var oct = tag; + tag = 0; + while ((oct & 0x80) === 0x80) { + oct = buf.readUInt8(fail); + if (buf.isError(oct)) + return oct; + + tag <<= 7; + tag |= oct & 0x7f; + } + } else { + tag &= 0x1f; + } + var tagStr = der.tag[tag]; + + return { + cls: cls, + primitive: primitive, + tag: tag, + tagStr: tagStr + }; +} + +function derDecodeLen(buf, primitive, fail) { + var len = buf.readUInt8(fail); + if (buf.isError(len)) + return len; + + // Indefinite form + if (!primitive && len === 0x80) + return null; + + // Definite form + if ((len & 0x80) === 0) { + // Short form + return len; + } + + // Long form + var num = len & 0x7f; + if (num > 4) + return buf.error('length octect is too long'); + + len = 0; + for (var i = 0; i < num; i++) { + len <<= 8; + var j = buf.readUInt8(fail); + if (buf.isError(j)) + return j; + len |= j; + } + + return len; +} |