signify-ts/dist/keri/core/decrypter.js

Signing at the edge for KERI, ACDC, and KERIA

import libsodium from 'libsodium-wrappers-sumo';
import { Matter, MtrDex } from "./matter.js";
import { Signer } from "./signer.js";
import { Cipher } from "./cipher.js";
import { EmptyMaterialError } from "./kering.js";
import { Salter } from "./salter.js";
export class Decrypter extends Matter {
    constructor({ raw, code = MtrDex.X25519_Private, qb64, qb64b, qb2 }, seed = undefined) {
        try {
            super({ raw, code, qb64, qb64b, qb2 });
        }
        catch (e) {
            if (e instanceof EmptyMaterialError) {
                if (seed != undefined) {
                    const signer = new Signer({ qb64b: seed });
                    if (signer.code != MtrDex.Ed25519_Seed) {
                        throw new Error(`Unsupported signing seed derivation code ${signer.code}`);
                    }
                    const sigkey = new Uint8Array(signer.raw.length + signer.verfer.raw.length);
                    sigkey.set(signer.raw);
                    sigkey.set(signer.verfer.raw, signer.raw.length);
                    raw =
                        libsodium.crypto_sign_ed25519_sk_to_curve25519(sigkey);
                    super({ raw, code, qb64, qb64b, qb2 });
                }
                else {
                    throw e;
                }
            }
            else {
                throw e;
            }
        }
        if (this.code == MtrDex.X25519_Private) {
            this._decrypt = this._x25519;
        }
        else {
            throw new Error(`Unsupported decrypter code = ${this.code}.`);
        }
    }
    decrypt(ser = null, cipher = null, transferable = false) {
        if (ser == null && cipher == null) {
            throw new EmptyMaterialError('Neither ser or cipher were provided');
        }
        if (ser != null) {
            cipher = new Cipher({ qb64b: ser });
        }
        return this._decrypt(cipher, this.raw, transferable);
    }
    _x25519(cipher, prikey, transferable = false) {
        const pubkey = libsodium.crypto_scalarmult_base(prikey);
        const plain = libsodium.crypto_box_seal_open(cipher.raw, pubkey, prikey);
        if (cipher.code == MtrDex.X25519_Cipher_Salt) {
            return new Salter({ qb64b: plain });
        }
        else if (cipher.code == MtrDex.X25519_Cipher_Seed) {
            return new Signer({ qb64b: plain, transferable: transferable });
        }
        else {
            throw new Error(`Unsupported cipher text code == ${cipher.code}`);
        }
    }
}