jose
Version:
Universal 'JSON Web Almost Everything' - JWA, JWS, JWE, JWT, JWK with no dependencies
135 lines (134 loc) • 5.58 kB
JavaScript
import { KeyObject, createPublicKey } from 'crypto';
import { encode as base64url } from './base64url.js';
import Asn1SequenceDecoder from './asn1_sequence_decoder.js';
import { JOSENotSupported } from '../util/errors.js';
import getNamedCurve from './get_named_curve.js';
import { isCryptoKey, getKeyObject } from './webcrypto.js';
const keyToJWK = (key) => {
if (isCryptoKey(key)) {
key = getKeyObject(key);
}
if (!(key instanceof KeyObject)) {
throw new TypeError('invalid key argument type');
}
switch (key.type) {
case 'secret':
return {
kty: 'oct',
k: base64url(key.export()),
};
case 'private':
case 'public': {
switch (key.asymmetricKeyType) {
case 'rsa': {
const der = key.export({ format: 'der', type: 'pkcs1' });
const dec = new Asn1SequenceDecoder(der);
if (key.type === 'private') {
dec.unsignedInteger();
}
const n = base64url(dec.unsignedInteger());
const e = base64url(dec.unsignedInteger());
let jwk;
if (key.type === 'private') {
jwk = {
d: base64url(dec.unsignedInteger()),
p: base64url(dec.unsignedInteger()),
q: base64url(dec.unsignedInteger()),
dp: base64url(dec.unsignedInteger()),
dq: base64url(dec.unsignedInteger()),
qi: base64url(dec.unsignedInteger()),
};
}
dec.end();
return { kty: 'RSA', n, e, ...jwk };
}
case 'ec': {
const crv = getNamedCurve(key);
let len;
let offset;
let correction;
switch (crv) {
case 'secp256k1':
len = 64;
offset = 31 + 2;
correction = -1;
break;
case 'P-256':
len = 64;
offset = 34 + 2;
correction = -1;
break;
case 'P-384':
len = 96;
offset = 33 + 2;
correction = -3;
break;
case 'P-521':
len = 132;
offset = 33 + 2;
correction = -3;
break;
default:
throw new JOSENotSupported('unsupported curve');
}
if (key.type === 'public') {
const der = key.export({ type: 'spki', format: 'der' });
return {
kty: 'EC',
crv,
x: base64url(der.subarray(-len, -len / 2)),
y: base64url(der.subarray(-len / 2)),
};
}
const der = key.export({ type: 'pkcs8', format: 'der' });
if (der.length < 100) {
offset += correction;
}
return {
...keyToJWK(createPublicKey(key)),
d: base64url(der.subarray(offset, offset + len / 2)),
};
}
case 'ed25519':
case 'x25519': {
const crv = getNamedCurve(key);
if (key.type === 'public') {
const der = key.export({ type: 'spki', format: 'der' });
return {
kty: 'OKP',
crv,
x: base64url(der.subarray(-32)),
};
}
const der = key.export({ type: 'pkcs8', format: 'der' });
return {
...keyToJWK(createPublicKey(key)),
d: base64url(der.subarray(-32)),
};
}
case 'ed448':
case 'x448': {
const crv = getNamedCurve(key);
if (key.type === 'public') {
const der = key.export({ type: 'spki', format: 'der' });
return {
kty: 'OKP',
crv,
x: base64url(der.subarray(crv === 'Ed448' ? -57 : -56)),
};
}
const der = key.export({ type: 'pkcs8', format: 'der' });
return {
...keyToJWK(createPublicKey(key)),
d: base64url(der.subarray(crv === 'Ed448' ? -57 : -56)),
};
}
default:
throw new JOSENotSupported('unsupported key asymmetricKeyType');
}
}
default:
throw new JOSENotSupported('unsupported key type');
}
};
export default keyToJWK;