Support curve25519 tentatively (#732)

.github/workflows/cd.yml

@@ -1,4 +1,4 @@
-name: Publish
+name: CD
 
 on:
   release:

.github/workflows/ci.yml

@@ -1,4 +1,4 @@
-name: Build
+name: CI
 
 on:
   push:

CHANGELOG.md

@@ -3,6 +3,7 @@
 
 ## 0.4.1 ~ 0.4.5
 
+- Support curve25519 (x25519 and ed25519) tentatively
 - Revamp browser compatibility
 - Export config
 - Fix symmetric encryption internal types
@@ -12,8 +13,8 @@
 
 ## 0.4.0
 
-- Change secp256k1 library to [noble-curves](https://github.com/paulmillr/noble-curves), which is [audited](https://github.com/paulmillr/noble-curves/tree/main/audit)
-- Change hash library to [noble-hashes](https://github.com/paulmillr/noble-hashes)
+- Change secp256k1 library to audited [noble-curves](https://github.com/paulmillr/noble-curves)
+- Change hash library to audited [noble-hashes](https://github.com/paulmillr/noble-hashes)
 - Change test library to [jest](https://jestjs.io/)
 - Bump dependencies
 - Drop Node 14 support

README.md

@@ -6,9 +6,9 @@
 [![CI](https://img.shields.io/github/actions/workflow/status/ecies/js/ci.yml)](https://github.com/ecies/js/actions)
 [![Codecov](https://img.shields.io/codecov/c/github/ecies/js.svg)](https://codecov.io/gh/ecies/js)
 
-Elliptic Curve Integrated Encryption Scheme for secp256k1 in TypeScript.
+Elliptic Curve Integrated Encryption Scheme for secp256k1/curve25519 in TypeScript.
 
-This is the JavaScript/TypeScript version of [eciespy](https://github.com/ecies/py) with a built-in class-like secp256k1 [API](#privatekey), you may go there for detailed documentation and learn the mechanism under the hood.
+This is the JavaScript/TypeScript version of [eciespy](https://github.com/ecies/py) with a built-in class-like secp256k1/curve25519 [API](#privatekey), you may go there for detailed documentation and learn the mechanism under the hood.
 
 If you want a WASM version to run directly in modern browsers or on some blockchains, check [`ecies-wasm`](https://github.com/ecies/rs-wasm).
 
@@ -30,13 +30,15 @@ Run the code below with `npx ts-node`.
 'hello world🌍'
 ```
 
+See [Configuration](#configuration) to control with more granularity.
+
 ## API
 
 ### `encrypt(receiverRawPK: string | Uint8Array, msg: Uint8Array): Buffer`
 
 Parameters:
 
-- **receiverRawPK** - Receiver's secp256k1 public key, hex string or buffer
+- **receiverRawPK** - Receiver's public key, hex string or buffer
 - **msg** - Data to encrypt
 
 Returns: **Buffer**
@@ -45,7 +47,7 @@ Returns: **Buffer**
 
 Parameters:
 
-- **receiverRawSK** - Receiver's secp256k1 private key, hex string or buffer
+- **receiverRawSK** - Receiver's private key, hex string or buffer
 - **msg** - Data to decrypt
 
 Returns: **Buffer**
@@ -66,8 +68,9 @@ equals(other: PrivateKey): boolean;
 - Properties
 
 ```typescript
-readonly secret: Buffer;
+get secret(): Buffer;
 readonly publicKey: PublicKey;
+private readonly data;
 ```
 
 ### `PublicKey`
@@ -76,7 +79,7 @@ readonly publicKey: PublicKey;
 
 ```typescript
 static fromHex(hex: string): PublicKey;
-constructor(buffer: Uint8Array);
+constructor(data: Uint8Array);
 toHex(compressed?: boolean): string;
 decapsulate(sk: PrivateKey): Uint8Array;
 equals(other: PublicKey): boolean;
@@ -85,19 +88,30 @@ equals(other: PublicKey): boolean;
 - Properties
 
 ```typescript
-readonly uncompressed: Buffer;
-readonly compressed: Buffer;
+get uncompressed(): Buffer;
+get compressed(): Buffer;
+private readonly data;
 ```
 
 ## Configuration
 
-Ephemeral key format in the payload and shared key in the key derivation can be configured as compressed or uncompressed format.
+Following configurations are available.
+
+- Elliptic curve: secp256k1 or curve25519 (x25519/ed25519)
+- Ephemeral key format in the payload: compressed or uncompressed (only for secp256k1)
+- Shared elliptic curve key format in the key derivation: compressed or uncompressed (only for secp256k1)
+- Symmetric cipher algorithm: AES-256-GCM or XChaCha20-Poly1305
+- Symmetric nonce length: 12 or 16 bytes (only for AES-256-GCM)
+
+For compatibility, make sure different applications share the same configuration.
 
 ```ts
+export type EllipticCurve = "secp256k1" | "x25519" | "ed25519";
 export type SymmetricAlgorithm = "aes-256-gcm" | "xchacha20";
-export type NonceLength = 12 | 16; // bytes. Only for aes-256-gcm
+export type NonceLength = 12 | 16;
 
 class Config {
+  ellipticCurve: EllipticCurve = "secp256k1";
   isEphemeralKeyCompressed: boolean = false;
   isHkdfKeyCompressed: boolean = false;
   symmetricAlgorithm: SymmetricAlgorithm = "aes-256-gcm";
@@ -107,15 +121,32 @@ class Config {
 export const ECIES_CONFIG = new Config();
 ```
 
-For example, if you set `isEphemeralKeyCompressed = true`, the payload would be like: `33 Bytes + AES` instead of `65 Bytes + AES`.
+### Elliptic curve configuration
+
+If you set `ellipticCurve = "x25519"` or `ellipticCurve = "ed25519"`, x25519 (key exchange function on curve25519) or ed25519 (signature algorithm on curve25519) will be used for key exchange instead of secp256k1.
+
+In this case, the payload would always be: `32 Bytes + AES` regardless of `isEphemeralKeyCompressed`.
+
+> If you don't know how to choose between x25519 and ed25519, just use x25519 for efficiency.
+
+### Secp256k1-specific configuration
+
+If you set `isEphemeralKeyCompressed = true`, the payload would be: `33 Bytes + AES` instead of `65 Bytes + AES`.
 
 If you set `isHkdfKeyCompressed = true`, the hkdf key would be derived from `ephemeral public key (compressed) + shared public key (compressed)` instead of `ephemeral public key (uncompressed) + shared public key (uncompressed)`.
 
+### Symmetric cipher configuration
+
 If you set `symmetricAlgorithm = "xchacha20"`, plaintext data will encrypted with XChaCha20-Poly1305.
 
-If you set `symmetricNonceLength = 12`, then the nonce of aes-256-gcm would be 12 bytes. XChaCha20-Poly1305's nonce is always 24 bytes.
+If you set `symmetricNonceLength = 12`, the nonce of AES-256-GCM would be 12 bytes. XChaCha20-Poly1305's nonce is always 24 bytes.
 
-For compatibility, make sure different applications share the same configuration.
+## Security Audit
+
+Following dependencies are audited:
+
+- [noble-curves](https://github.com/paulmillr/noble-curves/tree/main/audit)
+- [noble-hashes](https://github.com/paulmillr/noble-hashes#security)
 
 ## Changelog
 

package.json

@@ -34,13 +34,13 @@
     "test": "jest"
   },
   "dependencies": {
-    "@noble/ciphers": "^0.2.0",
+    "@noble/ciphers": "^0.3.0",
     "@noble/curves": "^1.2.0",
     "@noble/hashes": "^1.3.2"
   },
   "devDependencies": {
     "@types/jest": "^29.5.4",
-    "@types/node": "^20.5.6",
+    "@types/node": "^20.5.8",
     "@types/node-fetch": "^2.6.4",
     "https-proxy-agent": "^7.0.1",
     "jest": "^29.6.4",