supersphincs
Overview
SuperSPHINCS combines the post-quantum SPHINCS with the more conventional RSASSA-PKCS1-v1_5 as a single signing scheme. SPHINCS is provided by sphincs.js and RSA signing is performed using rsasign.js.
Before signing, a SHA-512 hash is performed, using the current platform's native implementation where available or an efficient JavaScript implementation from TweetNaCl.js otherwise.
Example Usage
(async () => {
const keyPair /*: {privateKey: Uint8Array; publicKey: Uint8Array} */ =
await superSphincs.keyPair()
;
const message /*: Uint8Array */ =
new Uint8Array([104, 101, 108, 108, 111]) // "hello"
;
// Optional additional data argument, similar conceptually to what AEAD ciphers support.
// If specified, must be the same when signing and verifying. For more information and
// usage advice, see: https://download.libsodium.org/doc/secret-key_cryptography/aead.html
const additionalData /*: Uint8Array */ =
new Uint8Array([119, 111, 114, 108, 100]) // "world"
;
/* Combined signatures */
const signed /*: Uint8Array */ =
await superSphincs.sign(message, keyPair.privateKey, additionalData)
;
const verified /*: Uint8Array */ =
await superSphincs.open(signed, keyPair.publicKey, additionalData) // same as message
;
/* Detached signatures */
const signature /*: Uint8Array */ =
await superSphincs.signDetached(message, keyPair.privateKey, additionalData)
;
const isValid /*: boolean */ =
await superSphincs.verifyDetached(
signature,
message,
keyPair.publicKey,
additionalData
) // true
;
/* Export and optionally encrypt keys */
const keyData /*: {
private: {
rsa: string;
sphincs: string;
superSphincs: string;
};
public: {
rsa: string;
sphincs: string;
superSphincs: string;
};
} */ =
await superSphincs.exportKeys(keyPair, 'secret passphrase')
;
if (typeof localStorage === 'undefined') {
localStorage = {};
}
// May now save exported keys to disk (or whatever)
localStorage.superSphincsPrivateKey = keyData.private.superSphincs;
localStorage.sphincsPrivateKey = keyData.private.sphincs;
localStorage.rsaPrivateKey = keyData.private.rsa;
localStorage.superSphincsPublicKey = keyData.public.superSphincs;
localStorage.sphincsPublicKey = keyData.public.sphincs;
localStorage.rsaPublicKey = keyData.public.rsa;
/* Reconstruct an exported key using either the superSphincs
value or any pair of valid sphincs and rsa values */
const keyPair1 = await superSphincs.importKeys({
public: {
rsa: localStorage.rsaPublicKey,
sphincs: localStorage.sphincsPublicKey
}
});
// May now use keyPair1.publicKey as in the above examples
console.log('Import #1:');
console.log(keyPair1);
const keyPair2 = await superSphincs.importKeys(
{
private: {
superSphincs: localStorage.superSphincsPrivateKey
}
},
'secret passphrase'
);
// May now use keyPair2 as in the above examples
console.log('Import #2:');
console.log(keyPair2);
// Constructing an entirely new SuperSPHINCS key pair from
// the original SPHINCS key pair and a new RSA key pair
const keyPair3 = await superSphincs.importKeys(
{
private: {
rsa: (
await superSphincs.exportKeys(
await superSphincs.keyPair(),
'hunter2'
)
).private.rsa,
sphincs: localStorage.sphincsPrivateKey
}
},
{
rsa: 'hunter2',
sphincs: 'secret passphrase'
}
);
// May now use keyPair3 as in the above examples
console.log('Import #3:');
console.log(keyPair3);
})();
Changelog
Breaking changes in major versions:
6.0.0:
- Additional data optional with default value of
new Uint8Array(0)
.
5.0.0:
- Additional data format change.
4.0.0:
- As part of upgrading from asm.js to WebAssembly (with asm.js included as a fallback), the API is fully asynchronous.
3.0.0:
- General API cleanup.
2.0.0:
- Split into module (supersphincs.js) and standalone pre-bundled version (dist/supersphincs.js).