- added CS cryptographic routines
This commit is contained in:
Gian Demarmels
parent
3b10e30ca1
commit
003ba5e91b
@ -27,13 +27,13 @@ import {
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keyExchangeEcdheEddsa,
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stringToBytes,
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bytesToString,
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hash,
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deriveBSeed,
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csBlind,
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calcS,
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csUnblind,
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csVerify,
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CsSignature,
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scalarMultBase25519,
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deriveSecrets,
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calcRBlind,
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} from "./talerCrypto.js";
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import { sha512, kdf } from "./kdf.js";
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import * as nacl from "./nacl-fast.js";
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@ -42,6 +42,7 @@ import { initNodePrng } from "./prng-node.js";
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// Since we import nacl-fast directly (and not via index.node.ts), we need to
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// init the PRNG manually.
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initNodePrng();
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import bigint from "big-integer";
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import { AssertionError } from "assert";
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test("encoding", (t) => {
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@ -199,6 +200,37 @@ test("taler-exchange-tvg eddsa_ecdh #2", (t) => {
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});
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test("taler CS blind c", async (t) => {
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/**$
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* Test Vectors:
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{
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"operation": "cs_blind_signing",
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"message_hash": "KZ7540050MWFPPPJ6C0910TC15AWD6KN6GMK4YH8PY5Z2RKP7NQMHZ1NDD7JHD9CA2CZXDKYN7XRX521YERAF6N50VJZMHWPH18TCFG",
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"cs_public_key": "1903SZ7QE1K8T4BHTJ32KDJ153SBXT22DGNQDY5NKJE535J72H2G",
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"cs_private_key": "K43QAMEPE9KJJTX6AJZD6N4SN1N3ARVAXZ2MRNPT85FHD4QD2C60",
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"cs_nonce": "GWPVFP9160XNADYQZ4T6S7RACB2482KG1JCY0X2Z5R52W74YXY3G",
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"cs_r_priv_0": "B01FJCRCST8JM10K17SJXY7S7HH7T65JMFQ03H6PNYY9Z167Q1T0",
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"cs_r_priv_1": "N3GW5X6VYSB8PY83CYNHJ3PN6TCA5N5BCS4WT2WEEQH7MTK915P0",
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"cs_r_pub_0": "J5XFBKFP9T6BM02H6ZV6Y568PQ2K398MD339036F25XTSP1A7T3G",
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"cs_r_pub_1": "GA2CZKJ6CWFS81ZN1T5R4GQFHF7XJV6HWHDR1JA9VATKKXQN89J0",
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"cs_bs_alpha_0": "R06FWJ4XEK4JKKKA03JARGD0PD5JAX8DK2N6J0K8CAZZMVQEJ1T0",
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"cs_bs_alpha_1": "13NXE2FEHJS0Q5XCWNRF4V1NC3BSAHN6BW02WZ07PG6967156HYG",
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"cs_bs_beta_0": "T3EZP42RJQXRTJ4FTDWF18Z422VX7KFGN8GJ3QCCM1QV3N456HD0",
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"cs_bs_beta_1": "P3MECYGCCR58QVEDSW443699CDXVT8C8W5ZT22PPNRJ363M72H6G",
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"cs_r_pub_blind_0": "CHK7JC4SXZ4Y9RDA3881S82F7BP99H35Q361WR6RBXN5YN2ZM1M0",
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"cs_r_pub_blind_1": "4C65R74GA9PPDX4DC2B948W96T3Z6QEENK2NDJQPNB9QBTKCT590",
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"cs_c_0": "F288QXT67TR36E6DHE399G8J24RM6C3DP16HGMH74B6WZ1DETR10",
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"cs_c_1": "EFK5WTN01NCVS3DZCG20MQDHRHBATRG8589BA0XSZDZ6D0HFR470",
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"cs_blind_s": "6KZF904YZA8KK4C8X5JV57E7B84SR8TDDN9GDC8QTRRSNTHJTM4G",
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"cs_b": "0000000",
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"cs_sig_s": "F4ZKMFW3Q7DFN0N94KAMG2JFFHAC362T0QZ6ZCVZ73RS8P91CR70",
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"cs_sig_R": "CHK7JC4SXZ4Y9RDA3881S82F7BP99H35Q361WR6RBXN5YN2ZM1M0",
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"cs_c_blind_0": "6TN5454DZCHBDXFAGQFXQY37FNX6YRKW0MPFEX4TG5EHXC98M840",
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"cs_c_blind_1": "EX6MYRZX6EC93YB4EE3M7AR3PQDYYG4092917YF29HD36X58NG0G",
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"cs_prehash_0": "D29BBP762HEN6ZHZ5T2T6S4VMV400K9Y659M1QQZYZ0WJS3V3EJSF0FVXSCD1E99JJJMW295EY8TEE97YEGSGEQ0Q0A9DDMS2NCAG9R",
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"cs_prehash_1": "9BYD02BC29ZF26BG88DWFCCENCS8CD8VZN76XP8JPWKTN9JS73MBCD0F36N0JSM223MRNJZACNYPMW23SGRHYVSP6BTT79GSSK5R228"
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}
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*/
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type CsBlindSignature = {
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sBlind: Uint8Array;
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rPubBlind: Uint8Array;
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@ -206,53 +238,114 @@ test("taler CS blind c", async (t) => {
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/**
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* CS denomination keypair
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*/
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const priv = "9TM70AKDTS57AWY9JK2J4TMBTMW6K62WHHGZWYDG0VM5ABPZKD40";
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const pub = "8GSJZ649T2PXMKZC01Y4ANNBE7MF14QVK9SQEC4E46ZHKCVG8AS0";
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const priv = "K43QAMEPE9KJJTX6AJZD6N4SN1N3ARVAXZ2MRNPT85FHD4QD2C60";
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const pub_cmp = "1903SZ7QE1K8T4BHTJ32KDJ153SBXT22DGNQDY5NKJE535J72H2G";
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const pub = await scalarMultBase25519(decodeCrock(priv));
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t.deepEqual(decodeCrock(pub_cmp), pub);
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const nonce = "GWPVFP9160XNADYQZ4T6S7RACB2482KG1JCY0X2Z5R52W74YXY3G";
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const msg_hash =
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"KZ7540050MWFPPPJ6C0910TC15AWD6KN6GMK4YH8PY5Z2RKP7NQMHZ1NDD7JHD9CA2CZXDKYN7XRX521YERAF6N50VJZMHWPH18TCFG";
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/**
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* rPub is returned from the exchange's new /csr API
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*/
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const rPriv1 = "9TM70AKDTS57AWY9JK2J4TMBTMW6K62WHHGZWYDG0VM5ABPZKD41";
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const rPriv2 = "8TM70AKDTS57AWY9JK2J4TMBTMW6K62WHHGZWYDG0VM5ABPZKD42";
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const rPub1 = nacl.crypto_sign_keyPair_fromSeed(
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decodeCrock(rPriv1),
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).publicKey;
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const rPub2 = nacl.crypto_sign_keyPair_fromSeed(
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decodeCrock(rPriv2),
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).publicKey;
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const rPub:[Uint8Array,Uint8Array] = [rPub1, rPub2];
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const rPriv0 = "B01FJCRCST8JM10K17SJXY7S7HH7T65JMFQ03H6PNYY9Z167Q1T0";
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const rPriv1 = "N3GW5X6VYSB8PY83CYNHJ3PN6TCA5N5BCS4WT2WEEQH7MTK915P0";
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const rPub0 = await scalarMultBase25519(decodeCrock(rPriv0));
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const rPub1 = await scalarMultBase25519(decodeCrock(rPriv1));
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const rPub: [Uint8Array, Uint8Array] = [rPub0, rPub1];
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t.deepEqual(
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rPub[0],
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decodeCrock("J5XFBKFP9T6BM02H6ZV6Y568PQ2K398MD339036F25XTSP1A7T3G"),
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);
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t.deepEqual(
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rPub[1],
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decodeCrock("GA2CZKJ6CWFS81ZN1T5R4GQFHF7XJV6HWHDR1JA9VATKKXQN89J0"),
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);
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/**
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* Coin key pair
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* Test if blinding seed derivation is deterministic
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* In the wallet the b-seed MUST be different from the Withdraw-Nonce or Refresh Nonce!
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* (Eg. derive two different values from coin priv) -> See CS protocols for details
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*/
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const priv_eddsa = "1KG54M8T3X8BSFSZXCR3SQBSR7Y9P53NX61M864S7TEVMJ2XVPF0";
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const pub_eddsa = eddsaGetPublic(decodeCrock(priv_eddsa));
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// const pub_eddsa = eddsaGetPublic(decodeCrock(priv_eddsa));
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const bseed1 = deriveBSeed(decodeCrock(priv_eddsa), rPub);
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const bseed2 = deriveBSeed(decodeCrock(priv_eddsa), rPub);
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t.deepEqual(bseed1, bseed2);
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const bseed = deriveBSeed(decodeCrock(priv_eddsa), [rPub1, rPub2]);
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/**
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* In this scenario the nonce from the test vectors is used as b-seed and refresh.
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* This is only used in testing to test functionality.
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* DO NOT USE the same values for blinding-seed and nonce anywhere else.
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*
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* Tests whether the blinding secrets are derived as in the exchange implementation
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*/
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const bseed = decodeCrock(nonce);
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const secrets = deriveSecrets(bseed);
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t.deepEqual(
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secrets.alpha[0],
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decodeCrock("R06FWJ4XEK4JKKKA03JARGD0PD5JAX8DK2N6J0K8CAZZMVQEJ1T0"),
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);
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t.deepEqual(
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secrets.alpha[1],
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decodeCrock("13NXE2FEHJS0Q5XCWNRF4V1NC3BSAHN6BW02WZ07PG6967156HYG"),
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);
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t.deepEqual(
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secrets.beta[0],
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decodeCrock("T3EZP42RJQXRTJ4FTDWF18Z422VX7KFGN8GJ3QCCM1QV3N456HD0"),
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);
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t.deepEqual(
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secrets.beta[1],
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decodeCrock("P3MECYGCCR58QVEDSW443699CDXVT8C8W5ZT22PPNRJ363M72H6G"),
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);
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// Check that derivation is deterministic
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const bseed2 = deriveBSeed(decodeCrock(priv_eddsa), [rPub1, rPub2]);
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t.deepEqual(bseed, bseed2);
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const rBlind = calcRBlind(pub, secrets, rPub);
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t.deepEqual(
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rBlind[0],
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decodeCrock("CHK7JC4SXZ4Y9RDA3881S82F7BP99H35Q361WR6RBXN5YN2ZM1M0"),
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);
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t.deepEqual(
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rBlind[1],
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decodeCrock("4C65R74GA9PPDX4DC2B948W96T3Z6QEENK2NDJQPNB9QBTKCT590"),
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);
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const coinPubHash = hash(pub_eddsa);
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const c = await csBlind(bseed, rPub, pub, decodeCrock(msg_hash));
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t.deepEqual(
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c[0],
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decodeCrock("F288QXT67TR36E6DHE399G8J24RM6C3DP16HGMH74B6WZ1DETR10"),
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);
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t.deepEqual(
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c[1],
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decodeCrock("EFK5WTN01NCVS3DZCG20MQDHRHBATRG8589BA0XSZDZ6D0HFR470"),
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);
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const c = await csBlind(bseed, [rPub1, rPub2], decodeCrock(pub), coinPubHash);
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const b = Buffer.from(kdf(1, decodeCrock(priv), new Uint8Array(),new Uint8Array())).readUInt8() % 2;
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if(b !=1 && b !=0){
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throw new AssertionError();
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const lMod = Array.from(
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new Uint8Array([
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0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x14, 0xde, 0xf9, 0xde, 0xa2, 0xf7, 0x9c, 0xd6,
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0x58, 0x12, 0x63, 0x1a, 0x5c, 0xf5, 0xd3, 0xed,
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]),
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);
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const L = bigint.fromArray(lMod, 256, false).toString();
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//Lmod needs to be 2^252+27742317777372353535851937790883648493
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if (!L.startsWith("723700")) {
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throw new AssertionError({ message: L });
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}
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const blindsig: CsBlindSignature ={
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sBlind: await calcS(rPub[b],c[b],decodeCrock(priv)),
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const b = 0;
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const blindsig: CsBlindSignature = {
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sBlind: decodeCrock("6KZF904YZA8KK4C8X5JV57E7B84SR8TDDN9GDC8QTRRSNTHJTM4G"),
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rPubBlind: rPub[b],
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};
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const sigblindsig: CsSignature = {
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s: blindsig.sBlind,
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rPub: blindsig.rPubBlind,
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};
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const sig = await csUnblind(bseed,rPub, decodeCrock(pub),b,blindsig);
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//const res = await csVerify(coinPubHash, sig, decodeCrock(pub));
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const sig = await csUnblind(bseed, rPub, pub, b, blindsig);
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t.deepEqual(sig.s, decodeCrock("F4ZKMFW3Q7DFN0N94KAMG2JFFHAC362T0QZ6ZCVZ73RS8P91CR70"));
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t.deepEqual(sig.rPub, decodeCrock("CHK7JC4SXZ4Y9RDA3881S82F7BP99H35Q361WR6RBXN5YN2ZM1M0"));
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const res = await csVerify(decodeCrock(msg_hash), sig, pub);
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t.deepEqual(res, true);
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});
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@ -24,7 +24,7 @@
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import * as nacl from "./nacl-fast.js";
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import { kdf } from "./kdf.js";
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import bigint from "big-integer";
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import sodium, { compare } from "libsodium-wrappers-sumo";
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import sodium from "libsodium-wrappers-sumo";
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import { DenominationPubKey, DenomKeyType } from "./talerTypes.js";
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import { AssertionError, equal } from "assert";
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@ -193,6 +193,32 @@ function kdfMod(
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}
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}
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function csKdfMod(
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n: bigint.BigInteger,
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ikm: Uint8Array,
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salt: Uint8Array,
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info: Uint8Array,
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): Uint8Array {
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const nbits = n.bitLength().toJSNumber();
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const buflen = Math.floor((nbits - 1) / 8 + 1);
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const mask = (1 << (8 - (buflen * 8 - nbits))) - 1;
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let counter = 0;
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while (true) {
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const ctx = new Uint8Array(info.byteLength + 2);
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ctx.set(info, 0);
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ctx[ctx.length - 2] = (counter >>> 8) & 0xff;
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ctx[ctx.length - 1] = counter & 0xff;
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const buf = kdf(buflen, ikm, salt, ctx);
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const arr = Array.from(buf);
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arr[0] = arr[0] & mask;
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const r = bigint.fromArray(arr, 256, false);
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if (r.lt(n)) {
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return new Uint8Array(arr);
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}
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counter++;
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}
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}
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// Newer versions of node have TextEncoder and TextDecoder as a global,
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// just like modern browsers.
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// In older versions of node or environments that do not have these
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@ -335,88 +361,153 @@ export type CsBlindSignature = {
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rPubBlind: Uint8Array;
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};
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type BlindingSecrets = {
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alpha: [Uint8Array,Uint8Array];
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beta: [Uint8Array,Uint8Array];
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export type CsBlindingSecrets = {
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alpha: [Uint8Array, Uint8Array];
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beta: [Uint8Array, Uint8Array];
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};
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//FIXME: Set correct salt
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function deriveSecrets(bseed: Uint8Array): BlindingSecrets {
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const outLen = 128;
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const salt = "94KPT83PCNS7J83KC5P78Y8";
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const rndout = kdf(outLen, bseed, decodeCrock(salt));
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const secrets: BlindingSecrets = {
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alpha: [rndout.slice(0, 32), rndout.slice(32, 64)],
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beta: [rndout.slice(64, 96), rndout.slice(96, 128)],
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function typedArrayConcat(chunks: Uint8Array[]): Uint8Array {
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let payloadLen = 0;
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for (const c of chunks) {
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payloadLen += c.byteLength;
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}
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const buf = new ArrayBuffer(payloadLen);
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const u8buf = new Uint8Array(buf);
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let p = 0;
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for (const c of chunks) {
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u8buf.set(c, p);
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p += c.byteLength;
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}
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return u8buf;
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}
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/**
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* Map to scalar subgroup function
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* perform clamping as described in RFC7748
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* @param scalar
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*/
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function mtoSS(scalar: Uint8Array): Uint8Array {
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scalar[0] &= 248;
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scalar[31] &= 127;
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scalar[31] |= 64;
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return scalar;
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}
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/**
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* The function returns the CS blinding secrets from a seed
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* @param bseed seed to derive blinding secrets
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* @returns blinding secrets
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*/
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export function deriveSecrets(bseed: Uint8Array): CsBlindingSecrets {
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const outLen = 130;
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const salt = stringToBytes("alphabeta");
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const rndout = kdf(outLen, bseed, salt);
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const secrets: CsBlindingSecrets = {
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alpha: [mtoSS(rndout.slice(0, 32)), mtoSS(rndout.slice(64, 96))],
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beta: [mtoSS(rndout.slice(32, 64)), mtoSS(rndout.slice(96, 128))],
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};
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return secrets;
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}
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function calcRDash(
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/**
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* Used for testing, simple scalar multiplication with base point of Cuve25519
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* @param s scalar
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* @returns new point sG
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*/
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export async function scalarMultBase25519(s: Uint8Array): Promise<Uint8Array> {
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await sodium.ready;
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return sodium.crypto_scalarmult_ed25519_base_noclamp(s);
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}
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/**
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* calculation of the blinded public point R in CS
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* @param csPub denomination publik key
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* @param secrets client blinding secrets
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* @param rPub public R received from /csr API
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*/
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export function calcRBlind(
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csPub: Uint8Array,
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secrets: BlindingSecrets,
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secrets: CsBlindingSecrets,
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rPub: [Uint8Array, Uint8Array],
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): [Uint8Array, Uint8Array] {
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//const aG1 = nacl.scalarMult_base();
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//const aG2 = nacl.scalarMult_base(secrets.alpha2);
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//const bDp1 = nacl.scalarMult(secrets.beta1, csPub);
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//const bDp2 = nacl.scalarMult(secrets.beta2, csPub);
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const aG0 = sodium.crypto_scalarmult_ed25519_base_noclamp(secrets.alpha[0]);
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const aG2 = sodium.crypto_scalarmult_ed25519_base_noclamp(secrets.alpha[1]);
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const aG1 = sodium.crypto_scalarmult_ed25519_base_noclamp(secrets.alpha[1]);
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|
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const bDp0 = sodium.crypto_scalarmult_ed25519(secrets.beta[0], csPub);
|
||||
const bDp1 = sodium.crypto_scalarmult_ed25519(secrets.beta[1], csPub);
|
||||
const bDp0 = sodium.crypto_scalarmult_ed25519_noclamp(secrets.beta[0], csPub);
|
||||
const bDp1 = sodium.crypto_scalarmult_ed25519_noclamp(secrets.beta[1], csPub);
|
||||
|
||||
const res0 = sodium.crypto_core_ed25519_add(aG0, bDp0);
|
||||
const res2 = sodium.crypto_core_ed25519_add(aG2, bDp1);
|
||||
const res1 = sodium.crypto_core_ed25519_add(aG1, bDp1);
|
||||
return [
|
||||
sodium.crypto_core_ed25519_add(rPub[0], res0),
|
||||
sodium.crypto_core_ed25519_add(rPub[1], res2),
|
||||
sodium.crypto_core_ed25519_add(rPub[1], res1),
|
||||
];
|
||||
}
|
||||
|
||||
//FIXME: How to pad two ikms correctly?
|
||||
//FIXME:_Is kdfMod used correctly?
|
||||
//FIXME: CDash1 is a JS Number array -> are they broken? how to convert bigint back to uint8arrays?
|
||||
/**
|
||||
* FDH function used in CS
|
||||
* @param hm message hash
|
||||
* @param rPub public R included in FDH
|
||||
* @param csPub denomination public key as context
|
||||
* @returns mapped Curve25519 scalar
|
||||
*/
|
||||
function csFDH(
|
||||
hm: Uint8Array,
|
||||
rPub: Uint8Array,
|
||||
) : Uint8Array{
|
||||
const lMod = Array.from(new Uint8Array([
|
||||
0xed, 0xd3, 0xf5, 0x5c, 0x1a, 0x63, 0x12, 0x58, 0xd6, 0x9c, 0xf7, 0xa2,
|
||||
0xde, 0xf9, 0xde, 0x14, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10,
|
||||
]));
|
||||
csPub: Uint8Array,
|
||||
): Uint8Array {
|
||||
const lMod = Array.from(
|
||||
new Uint8Array([
|
||||
0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0x00, 0x14, 0xde, 0xf9, 0xde, 0xa2, 0xf7, 0x9c, 0xd6,
|
||||
0x58, 0x12, 0x63, 0x1a, 0x5c, 0xf5, 0xd3, 0xed,
|
||||
]),
|
||||
);
|
||||
const L = bigint.fromArray(lMod, 256, false);
|
||||
const res = kdfMod(L, hm, rPub, rPub).toArray(256).value;
|
||||
return new Uint8Array(res);
|
||||
|
||||
const info = stringToBytes("Curve25519FDH");
|
||||
const preshash = sodium.crypto_hash_sha512(typedArrayConcat([rPub, hm]));
|
||||
return csKdfMod(L, preshash, csPub, info).reverse();
|
||||
}
|
||||
|
||||
|
||||
function deriveC(
|
||||
hm: Uint8Array,
|
||||
rPubDash: [Uint8Array, Uint8Array],
|
||||
): [Uint8Array, Uint8Array] {
|
||||
const cDash1 = csFDH(hm,rPubDash[0]);
|
||||
const cDash2 = csFDH(hm,rPubDash[1]);
|
||||
return [cDash1, cDash2];
|
||||
}
|
||||
|
||||
|
||||
//FIXME: Set correct salt and do correct KDF
|
||||
// How to do this in one round with Uint8Array?
|
||||
// How to pad two ikms correctly?
|
||||
/**
|
||||
* blinding seed derived from coin private key
|
||||
* @param coinPriv private key of the corresponding coin
|
||||
* @param rPub public R received from /csr API
|
||||
* @returns blinding seed
|
||||
*/
|
||||
export function deriveBSeed(
|
||||
coinPriv: Uint8Array,
|
||||
rPub: [Uint8Array, Uint8Array],
|
||||
): Uint8Array {
|
||||
const outLen = 32;
|
||||
const salt = "94KPT83PCNS7J83KC5P78Y8";
|
||||
const res = kdf(outLen, coinPriv, decodeCrock(salt), rPub[0]);
|
||||
return kdf(outLen, res, decodeCrock(salt), rPub[1]);
|
||||
const salt = stringToBytes("b-seed");
|
||||
const ikm = typedArrayConcat([coinPriv, rPub[0], rPub[1]]);
|
||||
return kdf(outLen, ikm, salt);
|
||||
}
|
||||
|
||||
/**
|
||||
* Derive withdraw nonce, used in /csr request
|
||||
* Note: In withdraw protocol, the nonce is chosen randomly
|
||||
* @param coinPriv coin private key
|
||||
* @returns nonce
|
||||
*/
|
||||
export function deriveWithdrawNonce(
|
||||
coinPriv: Uint8Array,
|
||||
): Uint8Array {
|
||||
const outLen = 32;
|
||||
const salt = stringToBytes("n");
|
||||
return kdf(outLen, coinPriv, salt);
|
||||
}
|
||||
|
||||
/**
|
||||
* Blind operation for CS signatures, used after /csr call
|
||||
* @param bseed blinding seed to derive blinding secrets
|
||||
* @param rPub public R received from /csr
|
||||
* @param csPub denomination public key
|
||||
* @param hm message to blind
|
||||
* @returns two blinded c
|
||||
*/
|
||||
export async function csBlind(
|
||||
bseed: Uint8Array,
|
||||
rPub: [Uint8Array, Uint8Array],
|
||||
@ -425,25 +516,24 @@ export async function csBlind(
|
||||
): Promise<[Uint8Array, Uint8Array]> {
|
||||
await sodium.ready;
|
||||
const secrets = deriveSecrets(bseed);
|
||||
const rPubDash = calcRDash(csPub, secrets, rPub);
|
||||
const c = deriveC(hm, rPubDash);
|
||||
const rPubBlind = calcRBlind(csPub, secrets, rPub);
|
||||
const c_0 = csFDH(hm, rPubBlind[0], csPub);
|
||||
const c_1 = csFDH(hm, rPubBlind[1], csPub);
|
||||
return [
|
||||
sodium.crypto_core_ed25519_scalar_add(c[0], secrets.beta[0]),
|
||||
sodium.crypto_core_ed25519_scalar_add(c[1], secrets.beta[1]),
|
||||
sodium.crypto_core_ed25519_scalar_add(c_0, secrets.beta[0]),
|
||||
sodium.crypto_core_ed25519_scalar_add(c_1, secrets.beta[1]),
|
||||
];
|
||||
}
|
||||
|
||||
export async function calcS(
|
||||
rPubB: Uint8Array,
|
||||
cB: Uint8Array,
|
||||
csPriv: Uint8Array,
|
||||
): Promise<Uint8Array> {
|
||||
await sodium.ready;
|
||||
const cBcsPriv = sodium.crypto_core_ed25519_scalar_mul(cB,csPriv);
|
||||
return sodium.crypto_core_ed25519_scalar_add(rPubB,cBcsPriv);
|
||||
}
|
||||
|
||||
//FIXME: Whats an int here??
|
||||
/**
|
||||
* Unblind operation to unblind the signature
|
||||
* @param bseed seed to derive secrets
|
||||
* @param rPub public R received from /csr
|
||||
* @param csPub denomination publick key
|
||||
* @param b returned from exchange to select c
|
||||
* @param csSig blinded signature
|
||||
* @returns unblinded signature
|
||||
*/
|
||||
export async function csUnblind(
|
||||
bseed: Uint8Array,
|
||||
rPub: [Uint8Array, Uint8Array],
|
||||
@ -451,31 +541,37 @@ export async function csUnblind(
|
||||
b: number,
|
||||
csSig: CsBlindSignature,
|
||||
): Promise<CsSignature> {
|
||||
|
||||
if(b != 0 && b !=1){
|
||||
if (b != 0 && b != 1) {
|
||||
throw new AssertionError();
|
||||
}
|
||||
await sodium.ready;
|
||||
const secrets = deriveSecrets(bseed);
|
||||
const rPubDash = calcRDash(csPub, secrets, rPub)[b];
|
||||
const sig :CsSignature = {
|
||||
const rPubDash = calcRBlind(csPub, secrets, rPub)[b];
|
||||
const sig: CsSignature = {
|
||||
s: sodium.crypto_core_ed25519_scalar_add(csSig.sBlind, secrets.alpha[b]),
|
||||
rPub: rPubDash,
|
||||
};
|
||||
return sig;
|
||||
}
|
||||
|
||||
/**
|
||||
* Verification algorithm for CS signatures
|
||||
* @param hm message signed
|
||||
* @param csSig unblinded signature
|
||||
* @param csPub denomination publick key
|
||||
* @returns true if valid, false if unvalid
|
||||
*/
|
||||
export async function csVerify(
|
||||
hm: Uint8Array,
|
||||
csSig: CsSignature,
|
||||
csPub: Uint8Array,
|
||||
): Promise<boolean> {
|
||||
await sodium.ready;
|
||||
const cDash = csFDH(hm, csSig.rPub);
|
||||
const cDash = csFDH(hm, csSig.rPub, csPub);
|
||||
const sG = sodium.crypto_scalarmult_ed25519_base_noclamp(csSig.s);
|
||||
const cbDp = sodium.crypto_scalarmult_ed25519_noclamp(cDash,csPub);
|
||||
const sGeq = sodium.crypto_core_ed25519_add(csSig.rPub,cbDp);
|
||||
return sodium.memcmp(sG,sGeq);
|
||||
const cbDp = sodium.crypto_scalarmult_ed25519_noclamp(cDash, csPub);
|
||||
const sGeq = sodium.crypto_core_ed25519_add(csSig.rPub, cbDp);
|
||||
return sodium.memcmp(sG, sGeq);
|
||||
}
|
||||
|
||||
export interface EddsaKeyPair {
|
||||
|
||||
Loading…
Reference in New Issue
Block a user