Add signer

packages/signer/src/util.ts

@@ -0,0 +1,60 @@
+import {schnorr} from '@noble/curves/secp256k1'
+import {bytesToHex, hexToBytes} from '@noble/hashes/utils'
+import {nip04 as nt04, nip44 as nt44, generateSecretKey, getPublicKey, getEventHash} from "nostr-tools"
+import {cached} from '@welshman/lib'
+import {SignedEvent, HashedEvent, EventTemplate, OwnedEvent} from '@welshman/util'
+
+export const getSecret = () => bytesToHex(generateSecretKey())
+
+export const getPubkey = (secret: string) => getPublicKey(hexToBytes(secret))
+
+export const getHash = (event: OwnedEvent) => getEventHash(event)
+
+export const getSig = (event: HashedEvent, secret: string) =>
+  bytesToHex(schnorr.sign(event.id, secret))
+
+export const own = (pubkey: string, event: EventTemplate) => ({...event, pubkey})
+
+export const hash = (event: OwnedEvent): HashedEvent => ({...event, id: getHash(event)})
+
+export const sign = (event: HashedEvent, secret: string) => ({...event, sig: getSig(event, secret)})
+
+export const nip04 = {
+  detect: (m: string) => m.includes("?iv="),
+  encrypt: (pubkey: string, secret: string, m: string) => nt04.encrypt(secret, pubkey, m),
+  decrypt: (pubkey: string, secret: string, m: string) =>  nt04.decrypt(secret, pubkey, m),
+}
+
+export const nip44 = {
+  getSharedSecret: cached({
+    maxSize: 10000,
+    getKey: ([secret, pubkey]) => [secret, pubkey].join(":"),
+    getValue: ([secret, pubkey]: string[]) => nt44.v2.utils.getConversationKey(hexToBytes(secret), pubkey),
+  }),
+  encrypt: (pubkey: string, secret: string, m: string) => nt44.v2.encrypt(m, nip44.getSharedSecret(secret, pubkey)),
+  decrypt: (pubkey: string, secret: string, m: string) => nt44.v2.decrypt(m, nip44.getSharedSecret(secret, pubkey)),
+}
+
+export type Sign = (event: EventTemplate) => Promise<SignedEvent>
+
+export type Encrypt = (pubkey: string, message: string) => Promise<string>
+
+export type Decrypt = (pubkey: string, message: string) => Promise<string>
+
+export type EncryptionImplementation = {
+  encrypt: Encrypt
+  decrypt: Decrypt
+}
+
+export interface ISigner {
+  isEnabled: () => boolean
+  getPubkey: () => Promise<string>
+  sign: Sign
+  nip04: EncryptionImplementation
+  nip44: EncryptionImplementation
+}
+
+export const decrypt = async (signer: ISigner, pubkey: string, message: string) =>
+  nip04.detect(message)
+    ? signer.nip04.decrypt(pubkey, message)
+    : signer.nip44.decrypt(pubkey, message)