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// Copyright 2017 Joyent, Inc.
module.exports = {
read: read,
verify: verify,
sign: sign,
signAsync: signAsync,
write: write
};
var assert = require('assert-plus');
var asn1 = require('asn1');
var Buffer = require('safer-buffer').Buffer;
var algs = require('../algs');
var utils = require('../utils');
var Key = require('../key');
var PrivateKey = require('../private-key');
var pem = require('./pem');
var Identity = require('../identity');
var Signature = require('../signature');
var Certificate = require('../certificate');
var pkcs8 = require('./pkcs8');
/*
* This file is based on RFC5280 (X.509).
*/
/* Helper to read in a single mpint */
function readMPInt(der, nm) {
assert.strictEqual(der.peek(), asn1.Ber.Integer,
nm + ' is not an Integer');
return (utils.mpNormalize(der.readString(asn1.Ber.Integer, true)));
}
function verify(cert, key) {
var sig = cert.signatures.x509;
assert.object(sig, 'x509 signature');
var algParts = sig.algo.split('-');
if (algParts[0] !== key.type)
return (false);
var blob = sig.cache;
if (blob === undefined) {
var der = new asn1.BerWriter();
writeTBSCert(cert, der);
blob = der.buffer;
}
var verifier = key.createVerify(algParts[1]);
verifier.write(blob);
return (verifier.verify(sig.signature));
}
function Local(i) {
return (asn1.Ber.Context | asn1.Ber.Constructor | i);
}
function Context(i) {
return (asn1.Ber.Context | i);
}
var SIGN_ALGS = {
'rsa-md5': '1.2.840.113549.1.1.4',
'rsa-sha1': '1.2.840.113549.1.1.5',
'rsa-sha256': '1.2.840.113549.1.1.11',
'rsa-sha384': '1.2.840.113549.1.1.12',
'rsa-sha512': '1.2.840.113549.1.1.13',
'dsa-sha1': '1.2.840.10040.4.3',
'dsa-sha256': '2.16.840.1.101.3.4.3.2',
'ecdsa-sha1': '1.2.840.10045.4.1',
'ecdsa-sha256': '1.2.840.10045.4.3.2',
'ecdsa-sha384': '1.2.840.10045.4.3.3',
'ecdsa-sha512': '1.2.840.10045.4.3.4',
'ed25519-sha512': '1.3.101.112'
};
Object.keys(SIGN_ALGS).forEach(function (k) {
SIGN_ALGS[SIGN_ALGS[k]] = k;
});
SIGN_ALGS['1.3.14.3.2.3'] = 'rsa-md5';
SIGN_ALGS['1.3.14.3.2.29'] = 'rsa-sha1';
var EXTS = {
'issuerKeyId': '2.5.29.35',
'altName': '2.5.29.17',
'basicConstraints': '2.5.29.19',
'keyUsage': '2.5.29.15',
'extKeyUsage': '2.5.29.37'
};
function read(buf, options) {
if (typeof (buf) === 'string') {
buf = Buffer.from(buf, 'binary');
}
assert.buffer(buf, 'buf');
var der = new asn1.BerReader(buf);
der.readSequence();
if (Math.abs(der.length - der.remain) > 1) {
throw (new Error('DER sequence does not contain whole byte ' +
'stream'));
}
var tbsStart = der.offset;
der.readSequence();
var sigOffset = der.offset + der.length;
var tbsEnd = sigOffset;
if (der.peek() === Local(0)) {
der.readSequence(Local(0));
var version = der.readInt();
assert.ok(version <= 3,
'only x.509 versions up to v3 supported');
}
var cert = {};
cert.signatures = {};
var sig = (cert.signatures.x509 = {});
sig.extras = {};
cert.serial = readMPInt(der, 'serial');
der.readSequence();
var after = der.offset + der.length;
var certAlgOid = der.readOID();
var certAlg = SIGN_ALGS[certAlgOid];
if (certAlg === undefined)
throw (new Error('unknown signature algorithm ' + certAlgOid));
der._offset = after;
cert.issuer = Identity.parseAsn1(der);
der.readSequence();
cert.validFrom = readDate(der);
cert.validUntil = readDate(der);
cert.subjects = [Identity.parseAsn1(der)];
der.readSequence();
after = der.offset + der.length;
cert.subjectKey = pkcs8.readPkcs8(undefined, 'public', der);
der._offset = after;
/* issuerUniqueID */
if (der.peek() === Local(1)) {
der.readSequence(Local(1));
sig.extras.issuerUniqueID =
buf.slice(der.offset, der.offset + der.length);
der._offset += der.length;
}
/* subjectUniqueID */
if (der.peek() === Local(2)) {
der.readSequence(Local(2));
sig.extras.subjectUniqueID =
buf.slice(der.offset, der.offset + der.length);
der._offset += der.length;
}
/* extensions */
if (der.peek() === Local(3)) {
der.readSequence(Local(3));
var extEnd = der.offset + der.length;
der.readSequence();
while (der.offset < extEnd)
readExtension(cert, buf, der);
assert.strictEqual(der.offset, extEnd);
}
assert.strictEqual(der.offset, sigOffset);
der.readSequence();
after = der.offset + der.length;
var sigAlgOid = der.readOID();
var sigAlg = SIGN_ALGS[sigAlgOid];
if (sigAlg === undefined)
throw (new Error('unknown signature algorithm ' + sigAlgOid));
der._offset = after;
var sigData = der.readString(asn1.Ber.BitString, true);
if (sigData[0] === 0)
sigData = sigData.slice(1);
var algParts = sigAlg.split('-');
sig.signature = Signature.parse(sigData, algParts[0], 'asn1');
sig.signature.hashAlgorithm = algParts[1];
sig.algo = sigAlg;
sig.cache = buf.slice(tbsStart, tbsEnd);
return (new Certificate(cert));
}
function readDate(der) {
if (der.peek() === asn1.Ber.UTCTime) {
return (utcTimeToDate(der.readString(asn1.Ber.UTCTime)));
} else if (der.peek() === asn1.Ber.GeneralizedTime) {
return (gTimeToDate(der.readString(asn1.Ber.GeneralizedTime)));
} else {
throw (new Error('Unsupported date format'));
}
}
function writeDate(der, date) {
if (date.getUTCFullYear() >= 2050 || date.getUTCFullYear() < 1950) {
der.writeString(dateToGTime(date), asn1.Ber.GeneralizedTime);
} else {
der.writeString(dateToUTCTime(date), asn1.Ber.UTCTime);
}
}
/* RFC5280, section 4.2.1.6 (GeneralName type) */
var ALTNAME = {
OtherName: Local(0),
RFC822Name: Context(1),
DNSName: Context(2),
X400Address: Local(3),
DirectoryName: Local(4),
EDIPartyName: Local(5),
URI: Context(6),
IPAddress: Context(7),
OID: Context(8)
};
/* RFC5280, section 4.2.1.12 (KeyPurposeId) */
var EXTPURPOSE = {
'serverAuth': '1.3.6.1.5.5.7.3.1',
'clientAuth': '1.3.6.1.5.5.7.3.2',
'codeSigning': '1.3.6.1.5.5.7.3.3',
/* See https://github.com/joyent/oid-docs/blob/master/root.md */
'joyentDocker': '1.3.6.1.4.1.38678.1.4.1',
'joyentCmon': '1.3.6.1.4.1.38678.1.4.2'
};
var EXTPURPOSE_REV = {};
Object.keys(EXTPURPOSE).forEach(function (k) {
EXTPURPOSE_REV[EXTPURPOSE[k]] = k;
});
var KEYUSEBITS = [
'signature', 'identity', 'keyEncryption',
'encryption', 'keyAgreement', 'ca', 'crl'
];
function readExtension(cert, buf, der) {
der.readSequence();
var after = der.offset + der.length;
var extId = der.readOID();
var id;
var sig = cert.signatures.x509;
if (!sig.extras.exts)
sig.extras.exts = [];
var critical;
if (der.peek() === asn1.Ber.Boolean)
critical = der.readBoolean();
switch (extId) {
case (EXTS.basicConstraints):
der.readSequence(asn1.Ber.OctetString);
der.readSequence();
var bcEnd = der.offset + der.length;
var ca = false;
if (der.peek() === asn1.Ber.Boolean)
ca = der.readBoolean();
if (cert.purposes === undefined)
cert.purposes = [];
if (ca === true)
cert.purposes.push('ca');
var bc = { oid: extId, critical: critical };
if (der.offset < bcEnd && der.peek() === asn1.Ber.Integer)
bc.pathLen = der.readInt();
sig.extras.exts.push(bc);
break;
case (EXTS.extKeyUsage):
der.readSequence(asn1.Ber.OctetString);
der.readSequence();
if (cert.purposes === undefined)
cert.purposes = [];
var ekEnd = der.offset + der.length;
while (der.offset < ekEnd) {
var oid = der.readOID();
cert.purposes.push(EXTPURPOSE_REV[oid] || oid);
}
/*
* This is a bit of a hack: in the case where we have a cert
* that's only allowed to do serverAuth or clientAuth (and not
* the other), we want to make sure all our Subjects are of
* the right type. But we already parsed our Subjects and
* decided if they were hosts or users earlier (since it appears
* first in the cert).
*
* So we go through and mutate them into the right kind here if
* it doesn't match. This might not be hugely beneficial, as it
* seems that single-purpose certs are not often seen in the
* wild.
*/
if (cert.purposes.indexOf('serverAuth') !== -1 &&
cert.purposes.indexOf('clientAuth') === -1) {
cert.subjects.forEach(function (ide) {
if (ide.type !== 'host') {
ide.type = 'host';
ide.hostname = ide.uid ||
ide.email ||
ide.components[0].value;
}
});
} else if (cert.purposes.indexOf('clientAuth') !== -1 &&
cert.purposes.indexOf('serverAuth') === -1) {
cert.subjects.forEach(function (ide) {
if (ide.type !== 'user') {
ide.type = 'user';
ide.uid = ide.hostname ||
ide.email ||
ide.components[0].value;
}
});
}
sig.extras.exts.push({ oid: extId, critical: critical });
break;
case (EXTS.keyUsage):
der.readSequence(asn1.Ber.OctetString);
var bits = der.readString(asn1.Ber.BitString, true);
var setBits = readBitField(bits, KEYUSEBITS);
setBits.forEach(function (bit) {
if (cert.purposes === undefined)
cert.purposes = [];
if (cert.purposes.indexOf(bit) === -1)
cert.purposes.push(bit);
});
sig.extras.exts.push({ oid: extId, critical: critical,
bits: bits });
break;
case (EXTS.altName):
der.readSequence(asn1.Ber.OctetString);
der.readSequence();
var aeEnd = der.offset + der.length;
while (der.offset < aeEnd) {
switch (der.peek()) {
case ALTNAME.OtherName:
case ALTNAME.EDIPartyName:
der.readSequence();
der._offset += der.length;
break;
case ALTNAME.OID:
der.readOID(ALTNAME.OID);
break;
case ALTNAME.RFC822Name:
/* RFC822 specifies email addresses */
var email = der.readString(ALTNAME.RFC822Name);
id = Identity.forEmail(email);
if (!cert.subjects[0].equals(id))
cert.subjects.push(id);
break;
case ALTNAME.DirectoryName:
der.readSequence(ALTNAME.DirectoryName);
id = Identity.parseAsn1(der);
if (!cert.subjects[0].equals(id))
cert.subjects.push(id);
break;
case ALTNAME.DNSName:
var host = der.readString(
ALTNAME.DNSName);
id = Identity.forHost(host);
if (!cert.subjects[0].equals(id))
cert.subjects.push(id);
break;
default:
der.readString(der.peek());
break;
}
}
sig.extras.exts.push({ oid: extId, critical: critical });
break;
default:
sig.extras.exts.push({
oid: extId,
critical: critical,
data: der.readString(asn1.Ber.OctetString, true)
});
break;
}
der._offset = after;
}
var UTCTIME_RE =
/^([0-9]{2})([0-9]{2})([0-9]{2})([0-9]{2})([0-9]{2})([0-9]{2})?Z$/;
function utcTimeToDate(t) {
var m = t.match(UTCTIME_RE);
assert.ok(m, 'timestamps must be in UTC');
var d = new Date();
var thisYear = d.getUTCFullYear();
var century = Math.floor(thisYear / 100) * 100;
var year = parseInt(m[1], 10);
if (thisYear % 100 < 50 && year >= 60)
year += (century - 1);
else
year += century;
d.setUTCFullYear(year, parseInt(m[2], 10) - 1, parseInt(m[3], 10));
d.setUTCHours(parseInt(m[4], 10), parseInt(m[5], 10));
if (m[6] && m[6].length > 0)
d.setUTCSeconds(parseInt(m[6], 10));
return (d);
}
var GTIME_RE =
/^([0-9]{4})([0-9]{2})([0-9]{2})([0-9]{2})([0-9]{2})([0-9]{2})?Z$/;
function gTimeToDate(t) {
var m = t.match(GTIME_RE);
assert.ok(m);
var d = new Date();
d.setUTCFullYear(parseInt(m[1], 10), parseInt(m[2], 10) - 1,
parseInt(m[3], 10));
d.setUTCHours(parseInt(m[4], 10), parseInt(m[5], 10));
if (m[6] && m[6].length > 0)
d.setUTCSeconds(parseInt(m[6], 10));
return (d);
}
function zeroPad(n, m) {
if (m === undefined)
m = 2;
var s = '' + n;
while (s.length < m)
s = '0' + s;
return (s);
}
function dateToUTCTime(d) {
var s = '';
s += zeroPad(d.getUTCFullYear() % 100);
s += zeroPad(d.getUTCMonth() + 1);
s += zeroPad(d.getUTCDate());
s += zeroPad(d.getUTCHours());
s += zeroPad(d.getUTCMinutes());
s += zeroPad(d.getUTCSeconds());
s += 'Z';
return (s);
}
function dateToGTime(d) {
var s = '';
s += zeroPad(d.getUTCFullYear(), 4);
s += zeroPad(d.getUTCMonth() + 1);
s += zeroPad(d.getUTCDate());
s += zeroPad(d.getUTCHours());
s += zeroPad(d.getUTCMinutes());
s += zeroPad(d.getUTCSeconds());
s += 'Z';
return (s);
}
function sign(cert, key) {
if (cert.signatures.x509 === undefined)
cert.signatures.x509 = {};
var sig = cert.signatures.x509;
sig.algo = key.type + '-' + key.defaultHashAlgorithm();
if (SIGN_ALGS[sig.algo] === undefined)
return (false);
var der = new asn1.BerWriter();
writeTBSCert(cert, der);
var blob = der.buffer;
sig.cache = blob;
var signer = key.createSign();
signer.write(blob);
cert.signatures.x509.signature = signer.sign();
return (true);
}
function signAsync(cert, signer, done) {
if (cert.signatures.x509 === undefined)
cert.signatures.x509 = {};
var sig = cert.signatures.x509;
var der = new asn1.BerWriter();
writeTBSCert(cert, der);
var blob = der.buffer;
sig.cache = blob;
signer(blob, function (err, signature) {
if (err) {
done(err);
return;
}
sig.algo = signature.type + '-' + signature.hashAlgorithm;
if (SIGN_ALGS[sig.algo] === undefined) {
done(new Error('Invalid signing algorithm "' +
sig.algo + '"'));
return;
}
sig.signature = signature;
done();
});
}
function write(cert, options) {
var sig = cert.signatures.x509;
assert.object(sig, 'x509 signature');
var der = new asn1.BerWriter();
der.startSequence();
if (sig.cache) {
der._ensure(sig.cache.length);
sig.cache.copy(der._buf, der._offset);
der._offset += sig.cache.length;
} else {
writeTBSCert(cert, der);
}
der.startSequence();
der.writeOID(SIGN_ALGS[sig.algo]);
if (sig.algo.match(/^rsa-/))
der.writeNull();
der.endSequence();
var sigData = sig.signature.toBuffer('asn1');
var data = Buffer.alloc(sigData.length + 1);
data[0] = 0;
sigData.copy(data, 1);
der.writeBuffer(data, asn1.Ber.BitString);
der.endSequence();
return (der.buffer);
}
function writeTBSCert(cert, der) {
var sig = cert.signatures.x509;
assert.object(sig, 'x509 signature');
der.startSequence();
der.startSequence(Local(0));
der.writeInt(2);
der.endSequence();
der.writeBuffer(utils.mpNormalize(cert.serial), asn1.Ber.Integer);
der.startSequence();
der.writeOID(SIGN_ALGS[sig.algo]);
if (sig.algo.match(/^rsa-/))
der.writeNull();
der.endSequence();
cert.issuer.toAsn1(der);
der.startSequence();
writeDate(der, cert.validFrom);
writeDate(der, cert.validUntil);
der.endSequence();
var subject = cert.subjects[0];
var altNames = cert.subjects.slice(1);
subject.toAsn1(der);
pkcs8.writePkcs8(der, cert.subjectKey);
if (sig.extras && sig.extras.issuerUniqueID) {
der.writeBuffer(sig.extras.issuerUniqueID, Local(1));
}
if (sig.extras && sig.extras.subjectUniqueID) {
der.writeBuffer(sig.extras.subjectUniqueID, Local(2));
}
if (altNames.length > 0 || subject.type === 'host' ||
(cert.purposes !== undefined && cert.purposes.length > 0) ||
(sig.extras && sig.extras.exts)) {
der.startSequence(Local(3));
der.startSequence();
var exts = [];
if (cert.purposes !== undefined && cert.purposes.length > 0) {
exts.push({
oid: EXTS.basicConstraints,
critical: true
});
exts.push({
oid: EXTS.keyUsage,
critical: true
});
exts.push({
oid: EXTS.extKeyUsage,
critical: true
});
}
exts.push({ oid: EXTS.altName });
if (sig.extras && sig.extras.exts)
exts = sig.extras.exts;
for (var i = 0; i < exts.length; ++i) {
der.startSequence();
der.writeOID(exts[i].oid);
if (exts[i].critical !== undefined)
der.writeBoolean(exts[i].critical);
if (exts[i].oid === EXTS.altName) {
der.startSequence(asn1.Ber.OctetString);
der.startSequence();
if (subject.type === 'host') {
der.writeString(subject.hostname,
Context(2));
}
for (var j = 0; j < altNames.length; ++j) {
if (altNames[j].type === 'host') {
der.writeString(
altNames[j].hostname,
ALTNAME.DNSName);
} else if (altNames[j].type ===
'email') {
der.writeString(
altNames[j].email,
ALTNAME.RFC822Name);
} else {
/*
* Encode anything else as a
* DN style name for now.
*/
der.startSequence(
ALTNAME.DirectoryName);
altNames[j].toAsn1(der);
der.endSequence();
}
}
der.endSequence();
der.endSequence();
} else if (exts[i].oid === EXTS.basicConstraints) {
der.startSequence(asn1.Ber.OctetString);
der.startSequence();
var ca = (cert.purposes.indexOf('ca') !== -1);
var pathLen = exts[i].pathLen;
der.writeBoolean(ca);
if (pathLen !== undefined)
der.writeInt(pathLen);
der.endSequence();
der.endSequence();
} else if (exts[i].oid === EXTS.extKeyUsage) {
der.startSequence(asn1.Ber.OctetString);
der.startSequence();
cert.purposes.forEach(function (purpose) {
if (purpose === 'ca')
return;
if (KEYUSEBITS.indexOf(purpose) !== -1)
return;
var oid = purpose;
if (EXTPURPOSE[purpose] !== undefined)
oid = EXTPURPOSE[purpose];
der.writeOID(oid);
});
der.endSequence();
der.endSequence();
} else if (exts[i].oid === EXTS.keyUsage) {
der.startSequence(asn1.Ber.OctetString);
/*
* If we parsed this certificate from a byte
* stream (i.e. we didn't generate it in sshpk)
* then we'll have a ".bits" property on the
* ext with the original raw byte contents.
*
* If we have this, use it here instead of
* regenerating it. This guarantees we output
* the same data we parsed, so signatures still
* validate.
*/
if (exts[i].bits !== undefined) {
der.writeBuffer(exts[i].bits,
asn1.Ber.BitString);
} else {
var bits = writeBitField(cert.purposes,
KEYUSEBITS);
der.writeBuffer(bits,
asn1.Ber.BitString);
}
der.endSequence();
} else {
der.writeBuffer(exts[i].data,
asn1.Ber.OctetString);
}
der.endSequence();
}
der.endSequence();
der.endSequence();
}
der.endSequence();
}
/*
* Reads an ASN.1 BER bitfield out of the Buffer produced by doing
* `BerReader#readString(asn1.Ber.BitString)`. That function gives us the raw
* contents of the BitString tag, which is a count of unused bits followed by
* the bits as a right-padded byte string.
*
* `bits` is the Buffer, `bitIndex` should contain an array of string names
* for the bits in the string, ordered starting with bit #0 in the ASN.1 spec.
*
* Returns an array of Strings, the names of the bits that were set to 1.
*/
function readBitField(bits, bitIndex) {
var bitLen = 8 * (bits.length - 1) - bits[0];
var setBits = {};
for (var i = 0; i < bitLen; ++i) {
var byteN = 1 + Math.floor(i / 8);
var bit = 7 - (i % 8);
var mask = 1 << bit;
var bitVal = ((bits[byteN] & mask) !== 0);
var name = bitIndex[i];
if (bitVal && typeof (name) === 'string') {
setBits[name] = true;
}
}
return (Object.keys(setBits));
}
/*
* `setBits` is an array of strings, containing the names for each bit that
* sould be set to 1. `bitIndex` is same as in `readBitField()`.
*
* Returns a Buffer, ready to be written out with `BerWriter#writeString()`.
*/
function writeBitField(setBits, bitIndex) {
var bitLen = bitIndex.length;
var blen = Math.ceil(bitLen / 8);
var unused = blen * 8 - bitLen;
var bits = Buffer.alloc(1 + blen); // zero-filled
bits[0] = unused;
for (var i = 0; i < bitLen; ++i) {
var byteN = 1 + Math.floor(i / 8);
var bit = 7 - (i % 8);
var mask = 1 << bit;
var name = bitIndex[i];
if (name === undefined)
continue;
var bitVal = (setBits.indexOf(name) !== -1);
if (bitVal) {
bits[byteN] |= mask;
}
}
return (bits);
}