@dwn-protocol/id-sdk
Version:
SDK for accessing the features and capabilities
143 lines • 5.47 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.Bbs = void 0;
const bbs_signatures_1 = require("@mattrglobal/bbs-signatures");
/**
* The `Bbs` class provides an interface for BBS+ signature operations
* using the BLS12-381 pairing-friendly curve.
*
* BBS+ signatures enable multi-message signing where each attribute of
* a credential is signed as a separate message. This allows a holder
* to derive a zero-knowledge proof that selectively discloses only
* chosen attributes without revealing the full signed message set.
*
* Example usage:
*
* ```ts
* const keyPair = await Bbs.generateKeyPair();
* const messages = [
* new TextEncoder().encode('age=25'),
* new TextEncoder().encode('country=US'),
* ];
* const signature = await Bbs.sign({ keyPair, messages });
*
* const proof = await Bbs.createProof({
* publicKey: keyPair.publicKey,
* signature,
* messages,
* revealed: [1],
* nonce: new TextEncoder().encode('unique-nonce'),
* });
*
* const isValid = await Bbs.verifyProof({
* publicKey: keyPair.publicKey,
* proof,
* messages: [messages[1]],
* nonce: new TextEncoder().encode('unique-nonce'),
* });
* ```
*/
class Bbs {
/**
* Generates a BLS12-381 G2 key pair suitable for BBS+ signatures.
*
* @returns A Promise resolving to a `BbsKeyPair` with 96-byte public key and 32-byte secret key.
*/
static async generateKeyPair() {
const keyPair = await (0, bbs_signatures_1.generateBls12381G2KeyPair)();
return {
publicKey: keyPair.publicKey,
secretKey: keyPair.secretKey,
};
}
/**
* Signs a set of messages using BBS+ producing a single 112-byte signature.
* Each message is treated as a distinct attribute that can later be
* individually disclosed or hidden via `createProof`.
*
* @param options.keyPair - The BLS12-381 key pair (publicKey + secretKey).
* @param options.messages - Array of messages (Uint8Array) to sign.
* @returns A Promise resolving to the BBS+ signature as a Uint8Array.
*/
static async sign(options) {
const { keyPair, messages } = options;
if (!messages || messages.length === 0) {
throw new Error('At least one message is required for BBS+ signing');
}
const signature = await (0, bbs_signatures_1.blsSign)({
keyPair: {
publicKey: keyPair.publicKey,
secretKey: keyPair.secretKey,
},
messages,
});
return signature;
}
/**
* Verifies a BBS+ signature against the full set of original messages.
*
* @param options.publicKey - The 96-byte BLS12-381 G2 public key.
* @param options.signature - The 112-byte BBS+ signature.
* @param options.messages - The complete set of messages that were signed.
* @returns A Promise resolving to `true` if the signature is valid.
*/
static async verify(options) {
const { publicKey, signature, messages } = options;
const result = await (0, bbs_signatures_1.blsVerify)({
publicKey,
signature,
messages,
});
return result.verified;
}
/**
* Derives a zero-knowledge proof from a BBS+ signature that selectively
* discloses only the messages at the specified indices. The prover
* demonstrates knowledge of the full signature without revealing
* hidden messages.
*
* @param options.publicKey - The issuer's 96-byte BLS12-381 G2 public key.
* @param options.signature - The original 112-byte BBS+ signature.
* @param options.messages - The complete set of messages that were signed.
* @param options.revealed - Array of zero-based indices indicating which messages to disclose.
* @param options.nonce - A unique nonce to bind the proof to a specific verification session.
* @returns A Promise resolving to the derived proof as a Uint8Array.
*/
static async createProof(options) {
const { publicKey, signature, messages, revealed, nonce } = options;
if (!nonce || nonce.length === 0) {
throw new Error('A nonce is required for proof creation to prevent replay attacks');
}
const proof = await (0, bbs_signatures_1.blsCreateProof)({
signature,
publicKey,
messages,
nonce,
revealed,
});
return proof;
}
/**
* Verifies a BBS+ zero-knowledge selective disclosure proof.
* Only the disclosed messages (those at the `revealed` indices during
* proof creation) should be provided.
*
* @param options.publicKey - The issuer's 96-byte BLS12-381 G2 public key.
* @param options.proof - The derived proof from `createProof`.
* @param options.messages - Only the disclosed messages, in order of their original indices.
* @param options.nonce - The same nonce used during proof creation.
* @returns A Promise resolving to `true` if the proof is valid.
*/
static async verifyProof(options) {
const { publicKey, proof, messages, nonce } = options;
const result = await (0, bbs_signatures_1.blsVerifyProof)({
proof,
publicKey,
messages,
nonce,
});
return result.verified;
}
}
exports.Bbs = Bbs;
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