commit 28d808ba98fcb37fa5f041420219e894836aa559
parent 272af1340c7fa49e6bcbd76bcca00a4b5f94f39a
Author: Martin Schanzenbach <schanzen@gnunet.org>
Date: Tue, 4 Nov 2025 21:21:27 +0100
hpke cleanups and bug fixes. Test against test vectors in RFC
Diffstat:
2 files changed, 159 insertions(+), 41 deletions(-)
diff --git a/packages/taler-util/src/taler-crypto.test.ts b/packages/taler-util/src/taler-crypto.test.ts
@@ -42,6 +42,16 @@ import {
chacha20poly1305_ietf_encrypt,
chacha20poly1305_ietf_decrypt,
chacha20_ietf,
+ hpkeSealOneshot,
+ hpkeKemEncapsNorand,
+ hpkeSenderSetup,
+ hpkeKeySchedule,
+ HpkeRole,
+ HpkeMode,
+ hpkeSenderSetupNorand,
+ hpkeSealOneshotNorand,
+ hpkeComputeNonce,
+ hpkeOpenOneshot,
} from "./taler-crypto.js";
import { sha512 } from "./kdf.js";
import * as nacl from "./nacl-fast.js";
@@ -542,7 +552,7 @@ test("chacha20poly1305 test vector", async (t) => {
t.deepEqual(block0.slice(0, 32), polyKey);
// encrypt
const ciphertext = chacha20poly1305_ietf_encrypt(plaintextBytes, aad, nonce, key);
-
+
// decrypt
const plaintext = chacha20poly1305_ietf_decrypt(ciphertext, aad, nonce, key);
t.false(plaintext === undefined);
@@ -550,3 +560,61 @@ test("chacha20poly1305 test vector", async (t) => {
const plaintextStr = decoder.decode(plaintext);
t.deepEqual(plaintextStr, 'Ladies and Gentlemen of the class of \'99: If I could offer you only one tip for the future, sunscreen would be it.');
});
+
+
+// TV are from RFC9180. Not all intermediate steps tested.
+test("rfc9180 HPKE DHKEM(X25519, HKDF-SHA256), HKDF-SHA256, ChaCha20Poly1305 test vector", async (t) => {
+ const info = new Uint8Array([
+ 0x4f, 0x64, 0x65, 0x20,
+ 0x6f, 0x6e, 0x20, 0x61,
+ 0x20, 0x47, 0x72, 0x65,
+ 0x63, 0x69, 0x61, 0x6e,
+ 0x20, 0x55, 0x72, 0x6e,
+ ]);
+ const pkEm = new Uint8Array([
+ 0x1a, 0xfa, 0x08, 0xd3, 0xde, 0xc0, 0x47, 0xa6,
+ 0x43, 0x88, 0x51, 0x63, 0xf1, 0x18, 0x04, 0x76,
+ 0xfa, 0x7d, 0xdb, 0x54, 0xc6, 0xa8, 0x02, 0x9e,
+ 0xa3, 0x3f, 0x95, 0x79, 0x6b, 0xf2, 0xac, 0x4a,
+ ]);
+ const pkRm = new Uint8Array([
+ 0x43, 0x10, 0xee, 0x97, 0xd8, 0x8c, 0xc1, 0xf0, 0x88, 0xa5, 0x57, 0x6c, 0x77, 0xab, 0x0c, 0xf5, 0xc3, 0xac, 0x79, 0x7f, 0x3d, 0x95, 0x13, 0x9c, 0x6c, 0x84, 0xb5, 0x42, 0x9c, 0x59, 0x66, 0x2a,
+ ]);
+ const skRm = new Uint8Array([
+ 0x80, 0x57, 0x99, 0x1e, 0xef, 0x8f, 0x1f, 0x1a, 0xf1, 0x8f, 0x4a, 0x94, 0x91, 0xd1, 0x6a, 0x1c, 0xe3, 0x33, 0xf6, 0x95, 0xd4, 0xdb, 0x8e, 0x38, 0xda, 0x75, 0x97, 0x5c, 0x44, 0x78, 0xe0, 0xfb
+ ]);
+ const skEm = new Uint8Array([
+ 0xf4, 0xec, 0x9b, 0x33, 0xb7, 0x92, 0xc3, 0x72, 0xc1, 0xd2, 0xc2, 0x06, 0x35, 0x07, 0xb6, 0x84, 0xef, 0x92, 0x5b, 0x8c, 0x75, 0xa4, 0x2d, 0xbc, 0xbf, 0x57, 0xd6, 0x3c, 0xcd, 0x38, 0x16, 0x00,
+ ]);
+ const enc = pkEm;
+ const key = new Uint8Array([
+ 0xad, 0x27, 0x44, 0xde, 0x8e, 0x17, 0xf4, 0xeb, 0xba, 0x57, 0x5b, 0x3f, 0x5f, 0x5a, 0x8f, 0xa1, 0xf6, 0x9c, 0x2a, 0x07, 0xf6, 0xe7, 0x50, 0x0b, 0xc6, 0x0c, 0xa6, 0xe3, 0xe3, 0xec, 0x1c, 0x91,
+ ]);
+ const pt = new Uint8Array([
+ 0x42, 0x65, 0x61, 0x75, 0x74, 0x79, 0x20, 0x69, 0x73, 0x20, 0x74, 0x72, 0x75, 0x74, 0x68, 0x2c, 0x20, 0x74, 0x72, 0x75, 0x74, 0x68, 0x20, 0x62, 0x65, 0x61, 0x75, 0x74, 0x79,
+ ]);
+ const aad = new Uint8Array([
+ 0x43, 0x6f, 0x75, 0x6e, 0x74, 0x2d, 0x30,
+ ]);
+ const ct = new Uint8Array([
+ 0x1c, 0x52, 0x50, 0xd8, 0x03, 0x4e, 0xc2, 0xb7, 0x84, 0xba, 0x2c, 0xfd, 0x69, 0xdb, 0xdb, 0x8a, 0xf4, 0x06, 0xcf, 0xe3, 0xff, 0x93, 0x8e, 0x13, 0x1f, 0x0d, 0xef, 0x8c, 0x8b, 0x60, 0xb4, 0xdb, 0x21, 0x99, 0x3c, 0x62, 0xce, 0x81, 0x88, 0x3d, 0x2d, 0xd1, 0xb5, 0x1a, 0x28,
+ ]);
+ const nonce = new Uint8Array([
+ 0x5c, 0x4d, 0x98, 0x15, 0x06, 0x61, 0xb8, 0x48, 0x85, 0x3b, 0x54, 0x7f,
+ ]);
+ const ss = new Uint8Array([
+ 0x0b, 0xbe, 0x78, 0x49, 0x04, 0x12, 0xb4, 0xbb, 0xea, 0x48, 0x12, 0x66, 0x6f, 0x79, 0x16, 0x93, 0x2b, 0x82, 0x8b, 0xba, 0x79, 0x94, 0x24, 0x24, 0xab, 0xb6, 0x52, 0x44, 0x93, 0x0d, 0x69, 0xa7,
+ ]);
+ const [enc_cand, ss_cand] = hpkeKemEncapsNorand(pkRm, skEm);
+ t.deepEqual(enc_cand, enc);
+ const [enc_cand_setup, ctx_cand] = hpkeSenderSetupNorand(pkRm, skEm, info);
+ t.deepEqual(ctx_cand.key, key);
+ t.deepEqual(enc_cand_setup, enc);
+ t.deepEqual(ss_cand, ss);
+ const nonce_cand = hpkeComputeNonce(ctx_cand);
+ t.deepEqual(nonce_cand, nonce);
+ const ct_cand = hpkeSealOneshotNorand(pkRm, skEm, info, aad, pt);
+ t.deepEqual(ct_cand.slice(enc.length), ct);
+ const m_cand = hpkeOpenOneshot(skRm, info, aad, ct_cand);
+ t.deepEqual(m_cand, pt);
+});
diff --git a/packages/taler-util/src/taler-crypto.ts b/packages/taler-util/src/taler-crypto.ts
@@ -1758,10 +1758,45 @@ export function toHexString(byteArray: Uint8Array) {
);
}
+// RFC 9180 Hybrid Public-Key Encryption
+// Currently, no agility implemented, we only support
+// DHKEM(X25519, HKDF-SHA256), HKDF-SHA256, ChaCha20Poly1305
+
+// A X25519 public key
export type HpkePublicKey = Uint8Array
+// A X25519 secret key
+export type HpkeSecretKey = Uint8Array;
+
+// An X25519 public key
export type HpkeEncapsulation = Uint8Array
+// This makes sure that sender confusion is
+// avoided.
+// In a non-oneshot API (currently not implemented)
+// this is a requried input.
+export enum HpkeRole {
+ Sender,
+ Receiver,
+}
+
+// We do support pre-shared keys in this API.
+export enum HpkeMode {
+ Base = 0x00,
+ PSK = 0x01,
+}
+
+// Currently only used internally.
+// Necessary when we support anything
+// else than the oneshot APIs
+export interface HpkeContext {
+ key: Uint8Array,
+ nonce: Uint8Array,
+ seq: number,
+ role: HpkeRole,
+}
+
+
export function hkdf_extract_sha256(
ikm: Uint8Array,
salt?: Uint8Array,
@@ -1804,7 +1839,7 @@ export function hkdf_expand_sha256(
}
-export function labeledExpand(
+export function hpkeLabeledExpand(
ctx: string,
prk: Uint8Array,
label: string,
@@ -1820,7 +1855,7 @@ export function labeledExpand(
return hkdf_expand_sha256(outLength, prk, labeledInfo);
}
-export function labeledExtract(
+export function hpkeLabeledExtract(
ctx: string,
label: Uint8Array,
ikm: Uint8Array,
@@ -1854,11 +1889,11 @@ export function hpkeKemEncapsNorand(
const kem_context = new Uint8Array([...enc, ...pkR]);
const dh = ecdh_x25519 (skE, pkR);
const suiteId = new Uint8Array([0x4B,0x45,0x4D,0x00,0x20]);
- const prk = labeledExtract("HPKE-v1",
+ const prk = hpkeLabeledExtract("HPKE-v1",
stringToBytes("eae_prk"),
dh,
suiteId);
- const ss = labeledExpand("HPKE-v1",
+ const ss = hpkeLabeledExpand("HPKE-v1",
prk,
"shared_secret",
kem_context,
@@ -1874,11 +1909,11 @@ export function hpkeKemDecaps(
const dh = ecdh_x25519(skR, enc);
const kem_context = new Uint8Array([...enc, ...pkR]);
const suiteId = new Uint8Array([0x4B,0x45,0x4D,0x00,0x20]);
- const prk = labeledExtract("HPKE-v1",
+ const prk = hpkeLabeledExtract("HPKE-v1",
stringToBytes("eae_prk"),
dh,
suiteId);
- const ss = labeledExpand("HPKE-v1",
+ const ss = hpkeLabeledExpand("HPKE-v1",
prk,
"shared_secret",
kem_context,
@@ -1888,23 +1923,6 @@ export function hpkeKemDecaps(
}
-enum HpkeRole {
- Sender,
- Receiver,
-}
-
-enum HpkeMode {
- Base = 0x00,
- PSK = 0x01,
-}
-
-export interface HpkeContext {
- key: Uint8Array,
- nonce: Uint8Array,
- seq: number,
- role: HpkeRole,
-}
-
export function hpkeKeySchedule(
role: HpkeRole,
mode: HpkeMode,
@@ -1938,27 +1956,27 @@ export function hpkeKeySchedule(
}
}
const suiteIdBytes = new Uint8Array(suiteId);
- const pskIdHash = labeledExtract("HPKE-v1",
+ const pskIdHash = hpkeLabeledExtract("HPKE-v1",
stringToBytes("psk_id_hash"),
new Uint8Array([]),
suiteIdBytes);
- const infoHash = labeledExtract("HPKE-v1",
+ const infoHash = hpkeLabeledExtract("HPKE-v1",
stringToBytes("info_hash"),
info,
suiteIdBytes);
const keyScheduleCtx = new Uint8Array([mode, ...pskIdHash, ...infoHash]);
- const secret = labeledExtract("HPKE-v1",
+ const secret = hpkeLabeledExtract("HPKE-v1",
stringToBytes("secret"),
psk || new Uint8Array([]),
suiteIdBytes,
sharedSecret);
- const ctxKey = labeledExpand("HPKE-v1",
+ const ctxKey = hpkeLabeledExpand("HPKE-v1",
secret,
"key",
keyScheduleCtx,
suiteIdBytes,
32); // key 32 bytes / 256 bit
- const ctxNonce = labeledExpand("HPKE-v1",
+ const ctxNonce = hpkeLabeledExpand("HPKE-v1",
secret,
"base_nonce",
keyScheduleCtx,
@@ -1970,11 +1988,11 @@ export function hpkeKeySchedule(
}
-export function hpkeSenderSetup(
+export function hpkeSenderSetupNorand(
pkR: HpkePublicKey,
+ skE: HpkeSecretKey,
info: Uint8Array) : [HpkeEncapsulation, HpkeContext] {
- const keypair = createEcdheKeyPair();
- const [enc, sharedSecret] = hpkeKemEncapsNorand(pkR, keypair.ecdhePriv);
+ const [enc, sharedSecret] = hpkeKemEncapsNorand(pkR, skE);
const ctx = hpkeKeySchedule(HpkeRole.Sender,
HpkeMode.Base,
sharedSecret,
@@ -1982,18 +2000,51 @@ export function hpkeSenderSetup(
return [enc, ctx];
}
-function hpkeComputeNonce(
+
+export function hpkeSenderSetup(
+ pkR: HpkePublicKey,
+ info: Uint8Array) : [HpkeEncapsulation, HpkeContext] {
+ const keypair = createEcdheKeyPair();
+ return hpkeSenderSetupNorand(pkR, keypair.ecdhePriv, info);
+}
+
+export function hpkeComputeNonce(
ctx: HpkeContext) : Uint8Array {
const nonce = new ArrayBuffer(12);
+ const seqNboBuf = new ArrayBuffer(8);
const v = new DataView(nonce);
+ const vSeq = new DataView(seqNboBuf);
+ const seqNbo = new Uint8Array(seqNboBuf);
+ vSeq.setBigUint64(0, BigInt(ctx.seq));
const offset = 12 - 8; // nonce length - sequence counter of 64 bits
- for (let i = 0; i < offset; i++) {
- v.setUint8(i, ctx.nonce[i]);
+ let i = 0;
+ let j = 0;
+ for (i = 0; i < 12; i++) {
+ if (i < offset) {
+ v.setUint8(i, ctx.nonce[i]);
+ } else {
+ v.setUint8(i, ctx.nonce[i] ^ seqNbo[j++]);
+ }
}
- v.setBigUint64(offset, BigInt(ctx.seq));
return new Uint8Array(nonce);
}
+export function hpkeSealOneshotNorand(
+ pkR: HpkePublicKey,
+ skE: HpkeSecretKey,
+ info: Uint8Array,
+ aad: Uint8Array,
+ plaintext: Uint8Array): Uint8Array {
+ const [enc, ctx] = hpkeSenderSetupNorand(pkR, skE, info);
+ const nonce = hpkeComputeNonce(ctx);
+ const ct = chacha20poly1305_ietf_encrypt(plaintext,
+ aad,
+ nonce,
+ ctx.key);
+ ctx.seq++;
+ return new Uint8Array([...enc, ...ct]);
+}
+
export function hpkeSealOneshot(
pkR: HpkePublicKey,
info: Uint8Array,
@@ -2009,7 +2060,6 @@ export function hpkeSealOneshot(
return new Uint8Array([...enc, ...ct]);
}
-export type HpkeSecretKey = Uint8Array;
export function hpkeReceiverSetup(
enc: Uint8Array,
@@ -2032,7 +2082,7 @@ export function hpkeOpenOneshot(
skR,
info);
const nonce = hpkeComputeNonce(ctx);
- return chacha20poly1305_ietf_decrypt(ciphertext,
+ return chacha20poly1305_ietf_decrypt(ciphertext.slice(32),
aad,
nonce,
ctx.key);
@@ -2048,9 +2098,7 @@ export function hpkeCreateSecretKey() : HpkeSecretKey {
return keypair.ecdhePriv as HpkeSecretKey;
}
-export interface ChaCha20Context {
- input: Uint32Array,
-}
+// RFC 8439 ChaCha20-Poly1305 (IETF variants)
function chacha20_toUint32(data: Uint8Array | number[], index: number): number {
return data[index++] ^ (data[index++] << 8) ^ (data[index++] << 16) ^ (data[index] << 24)
@@ -2161,6 +2209,8 @@ export function chacha20_ietf_xor(
return out;
}
+
+
export function chacha20_ietf(
clen: number,
key: Uint8Array,
