NIP44: fix slow types

README.md

@@ -266,4 +266,8 @@ This is free and unencumbered software released into the public domain. By submi
 
 ## Contributing to this repository
 
-Use NIP-34 to send your patches to `naddr1qq9kummnw3ez6ar0dak8xqg5waehxw309aex2mrp0yhxummnw3ezucn8qyt8wumn8ghj7un9d3shjtnwdaehgu3wvfskueqpzemhxue69uhhyetvv9ujuurjd9kkzmpwdejhgq3q80cvv07tjdrrgpa0j7j7tmnyl2yr6yr7l8j4s3evf6u64th6gkwsxpqqqpmejdv00jq`.
+Use NIP-34 to send your patches to:
+
+```
+naddr1qq9kummnw3ez6ar0dak8xqg5waehxw309aex2mrp0yhxummnw3ezucn8qyt8wumn8ghj7un9d3shjtnwdaehgu3wvfskueqpzemhxue69uhhyetvv9ujuurjd9kkzmpwdejhgq3q80cvv07tjdrrgpa0j7j7tmnyl2yr6yr7l8j4s3evf6u64th6gkwsxpqqqpmejdv00jq
+```

nip44.ts

@@ -8,54 +8,59 @@ import { concatBytes, randomBytes, utf8ToBytes } from '@noble/hashes/utils'
 import { base64 } from '@scure/base'
 
 const decoder = new TextDecoder()
-const u = {
-  minPlaintextSize: 0x0001, // 1b msg => padded to 32b
-  maxPlaintextSize: 0xffff, // 65535 (64kb-1) => padded to 64kb
 
-  utf8Encode: utf8ToBytes,
-  utf8Decode(bytes: Uint8Array): string {
+class u {
+  static minPlaintextSize = 0x0001 // 1b msg => padded to 32b
+  static maxPlaintextSize = 0xffff // 65535 (64kb-1) => padded to 64kb
+
+  static utf8Encode = utf8ToBytes
+
+  static utf8Decode(bytes: Uint8Array): string {
     return decoder.decode(bytes)
-  },
+  }
 
-  getConversationKey(privkeyA: string, pubkeyB: string): Uint8Array {
+  static getConversationKey(privkeyA: string, pubkeyB: string): Uint8Array {
     const sharedX = secp256k1.getSharedSecret(privkeyA, '02' + pubkeyB).subarray(1, 33)
     return hkdf_extract(sha256, sharedX, 'nip44-v2')
-  },
+  }
 
-  getMessageKeys(conversationKey: Uint8Array, nonce: Uint8Array) {
+  static getMessageKeys(
+    conversationKey: Uint8Array,
+    nonce: Uint8Array,
+  ): { chacha_key: Uint8Array; chacha_nonce: Uint8Array; hmac_key: Uint8Array } {
     const keys = hkdf_expand(sha256, conversationKey, nonce, 76)
     return {
       chacha_key: keys.subarray(0, 32),
       chacha_nonce: keys.subarray(32, 44),
       hmac_key: keys.subarray(44, 76),
     }
-  },
+  }
 
-  calcPaddedLen(len: number): number {
+  static calcPaddedLen(len: number): number {
     if (!Number.isSafeInteger(len) || len < 1) throw new Error('expected positive integer')
     if (len <= 32) return 32
     const nextPower = 1 << (Math.floor(Math.log2(len - 1)) + 1)
     const chunk = nextPower <= 256 ? 32 : nextPower / 8
     return chunk * (Math.floor((len - 1) / chunk) + 1)
-  },
+  }
 
-  writeU16BE(num: number): Uint8Array {
+  static writeU16BE(num: number): Uint8Array {
     if (!Number.isSafeInteger(num) || num < u.minPlaintextSize || num > u.maxPlaintextSize)
       throw new Error('invalid plaintext size: must be between 1 and 65535 bytes')
     const arr = new Uint8Array(2)
     new DataView(arr.buffer).setUint16(0, num, false)
     return arr
-  },
+  }
 
-  pad(plaintext: string): Uint8Array {
+  static pad(plaintext: string): Uint8Array {
     const unpadded = u.utf8Encode(plaintext)
     const unpaddedLen = unpadded.length
     const prefix = u.writeU16BE(unpaddedLen)
     const suffix = new Uint8Array(u.calcPaddedLen(unpaddedLen) - unpaddedLen)
     return concatBytes(prefix, unpadded, suffix)
-  },
+  }
 
-  unpad(padded: Uint8Array): string {
+  static unpad(padded: Uint8Array): string {
     const unpaddedLen = new DataView(padded.buffer).getUint16(0)
     const unpadded = padded.subarray(2, 2 + unpaddedLen)
     if (
@@ -66,13 +71,13 @@ const u = {
     )
       throw new Error('invalid padding')
     return u.utf8Decode(unpadded)
-  },
+  }
 
-  hmacAad(key: Uint8Array, message: Uint8Array, aad: Uint8Array): Uint8Array {
+  static hmacAad(key: Uint8Array, message: Uint8Array, aad: Uint8Array): Uint8Array {
     if (aad.length !== 32) throw new Error('AAD associated data must be 32 bytes')
     const combined = concatBytes(aad, message)
     return hmac(sha256, key, combined)
-  },
+  }
 
   // metadata: always 65b (version: 1b, nonce: 32b, max: 32b)
   // plaintext: 1b to 0xffff
@@ -80,7 +85,7 @@ const u = {
   // ciphertext: 32b+2 to 0xffff+2
   // raw payload: 99 (65+32+2) to 65603 (65+0xffff+2)
   // compressed payload (base64): 132b to 87472b
-  decodePayload(payload: string): { nonce: Uint8Array; ciphertext: Uint8Array; mac: Uint8Array } {
+  static decodePayload(payload: string): { nonce: Uint8Array; ciphertext: Uint8Array; mac: Uint8Array } {
     if (typeof payload !== 'string') throw new Error('payload must be a valid string')
     const plen = payload.length
     if (plen < 132 || plen > 87472) throw new Error('invalid payload length: ' + plen)
@@ -100,30 +105,28 @@ const u = {
       ciphertext: data.subarray(33, -32),
       mac: data.subarray(-32),
     }
-  },
+  }
 }
 
-function encrypt(plaintext: string, conversationKey: Uint8Array, nonce: Uint8Array = randomBytes(32)): string {
-  const { chacha_key, chacha_nonce, hmac_key } = u.getMessageKeys(conversationKey, nonce)
-  const padded = u.pad(plaintext)
-  const ciphertext = chacha20(chacha_key, chacha_nonce, padded)
-  const mac = u.hmacAad(hmac_key, ciphertext, nonce)
-  return base64.encode(concatBytes(new Uint8Array([2]), nonce, ciphertext, mac))
-}
+export class v2 {
+  static utils = u
 
-function decrypt(payload: string, conversationKey: Uint8Array): string {
-  const { nonce, ciphertext, mac } = u.decodePayload(payload)
-  const { chacha_key, chacha_nonce, hmac_key } = u.getMessageKeys(conversationKey, nonce)
-  const calculatedMac = u.hmacAad(hmac_key, ciphertext, nonce)
-  if (!equalBytes(calculatedMac, mac)) throw new Error('invalid MAC')
-  const padded = chacha20(chacha_key, chacha_nonce, ciphertext)
-  return u.unpad(padded)
-}
+  static encrypt(plaintext: string, conversationKey: Uint8Array, nonce: Uint8Array = randomBytes(32)): string {
+    const { chacha_key, chacha_nonce, hmac_key } = u.getMessageKeys(conversationKey, nonce)
+    const padded = u.pad(plaintext)
+    const ciphertext = chacha20(chacha_key, chacha_nonce, padded)
+    const mac = u.hmacAad(hmac_key, ciphertext, nonce)
+    return base64.encode(concatBytes(new Uint8Array([2]), nonce, ciphertext, mac))
+  }
 
-export const v2 = {
-  utils: u,
-  encrypt,
-  decrypt,
+  static decrypt(payload: string, conversationKey: Uint8Array): string {
+    const { nonce, ciphertext, mac } = u.decodePayload(payload)
+    const { chacha_key, chacha_nonce, hmac_key } = u.getMessageKeys(conversationKey, nonce)
+    const calculatedMac = u.hmacAad(hmac_key, ciphertext, nonce)
+    if (!equalBytes(calculatedMac, mac)) throw new Error('invalid MAC')
+    const padded = chacha20(chacha_key, chacha_nonce, ciphertext)
+    return u.unpad(padded)
+  }
 }
 
 export default { v2 }