keypairs.js/lib/browser/rsa.js

60 lines
1.7 KiB
JavaScript

'use strict';
var native = module.exports;
// XXX added by caller: _stance, neuter
var RSA = native;
native.generate = function (opts) {
var wcOpts = {};
if (!opts) {
opts = {};
}
if (!opts.kty) {
opts.kty = 'RSA';
}
// Support PSS? I don't think it's used for Let's Encrypt
wcOpts.name = 'RSASSA-PKCS1-v1_5';
if (!opts.modulusLength) {
opts.modulusLength = 2048;
}
wcOpts.modulusLength = opts.modulusLength;
if (wcOpts.modulusLength >= 2048 && wcOpts.modulusLength < 3072) {
// erring on the small side... for no good reason
wcOpts.hash = { name: 'SHA-256' };
} else if (wcOpts.modulusLength >= 3072 && wcOpts.modulusLength < 4096) {
wcOpts.hash = { name: 'SHA-384' };
} else if (wcOpts.modulusLength < 4097) {
wcOpts.hash = { name: 'SHA-512' };
} else {
// Public key thumbprints should be paired with a hash of similar length,
// so anything above SHA-512's keyspace would be left under-represented anyway.
return Promise.Reject(
new Error(
"'" +
wcOpts.modulusLength +
"' is not within the safe and universally" +
' acceptable range of 2048-4096. Typically you should pick 2048, 3072, or 4096, though other values' +
' divisible by 8 are allowed. ' +
RSA._stance
)
);
}
// TODO maybe allow this to be set to any of the standard values?
wcOpts.publicExponent = new Uint8Array([0x01, 0x00, 0x01]);
var extractable = true;
return window.crypto.subtle
.generateKey(wcOpts, extractable, ['sign', 'verify'])
.then(function (result) {
return window.crypto.subtle
.exportKey('jwk', result.privateKey)
.then(function (privJwk) {
return {
private: privJwk,
public: RSA.neuter({ jwk: privJwk })
};
});
});
};