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fiatjaffiatjaf
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implement nip26 delegation.
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‎README.md

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@@ -202,6 +202,41 @@ sub.on('event', (event) => {
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})
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```
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### Performing and checking for delegation
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```js
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import {nip26, getPublicKey, generatePrivateKey} from 'nostr-tools'
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// delegator
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let sk1 = generatePrivateKey()
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let pk1 = getPublicKey(sk1)
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// delegatee
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let sk2 = generatePrivateKey()
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let pk2 = getPublicKey(sk2)
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// generate delegation
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let delegation = nip26.createDelegation(sk1, {
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pubkey: pk2,
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kind: 1,
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since: Math.round(Date.now() / 1000),
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until: Math.round(Date.now() / 1000) + 60 * 60 * 24 * 30 /* 30 days */
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})
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// the delegatee uses the delegation when building an event
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let event = {
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pubkey: pk2,
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kind: 1,
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created_at: Math.round(Date.now() / 1000),
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content: 'hello from a delegated key',
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tags: [['delegation', delegation.from, delegation.cond, delegation.sig]]
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}
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// finally any receiver of this event can check for the presence of a valid delegation tag
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let delegator = nip26.getDelegator(event)
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assert(delegator === pk1) // will be null if there is no delegation tag or if it is invalid
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```
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Please consult the tests or [the source code](https://github.com/fiatjaf/nostr-tools) for more information that isn't available here.
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### Using from the browser (if you don't want to use a bundler)

‎index.ts

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@@ -7,3 +7,13 @@ export * as nip04 from './nip04'
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export * as nip05 from './nip05'
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export * as nip06 from './nip06'
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export * as nip19 from './nip19'
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export * as nip26 from './nip26'
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// monkey patch secp256k1
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import * as secp256k1 from '@noble/secp256k1'
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import {hmac} from '@noble/hashes/hmac'
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import {sha256} from '@noble/hashes/sha256'
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secp256k1.utils.hmacSha256Sync = (key, ...msgs) =>
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hmac(sha256, key, secp256k1.utils.concatBytes(...msgs))
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secp256k1.utils.sha256Sync = (...msgs) =>
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sha256(secp256k1.utils.concatBytes(...msgs))

‎nip26.test.js

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/* eslint-env jest */
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const {nip26, getPublicKey, generatePrivateKey} = require('./lib/nostr.cjs')
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test('parse good delegation from NIP', async () => {
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expect(
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nip26.getDelegator({
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id: 'a080fd288b60ac2225ff2e2d815291bd730911e583e177302cc949a15dc2b2dc',
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pubkey:
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'62903b1ff41559daf9ee98ef1ae67cc52f301bb5ce26d14baba3052f649c3f49',
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created_at: 1660896109,
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kind: 1,
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tags: [
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[
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'delegation',
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'86f0689bd48dcd19c67a19d994f938ee34f251d8c39976290955ff585f2db42e',
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'kind=1&created_at>1640995200',
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'c33c88ba78ec3c760e49db591ac5f7b129e3887c8af7729795e85a0588007e5ac89b46549232d8f918eefd73e726cb450135314bfda419c030d0b6affe401ec1'
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]
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],
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content: 'Hello world',
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sig: 'cd4a3cd20dc61dcbc98324de561a07fd23b3d9702115920c0814b5fb822cc5b7c5bcdaf3fa326d24ed50c5b9c8214d66c75bae34e3a84c25e4d122afccb66eb6'
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})
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).toEqual('86f0689bd48dcd19c67a19d994f938ee34f251d8c39976290955ff585f2db42e')
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})
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test('parse bad delegations', async () => {
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expect(
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nip26.getDelegator({
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id: 'a080fd288b60ac2225ff2e2d815291bd730911e583e177302cc949a15dc2b2dc',
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pubkey:
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'62903b1ff41559daf9ee98ef1ae67cc52f301bb5ce26d14baba3052f649c3f49',
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created_at: 1660896109,
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kind: 1,
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tags: [
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[
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'delegation',
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'86f0689bd48dcd19c67a19d994f938ee34f251d8c39976290955ff585f2db42f',
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'kind=1&created_at>1640995200',
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'c33c88ba78ec3c760e49db591ac5f7b129e3887c8af7729795e85a0588007e5ac89b46549232d8f918eefd73e726cb450135314bfda419c030d0b6affe401ec1'
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]
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],
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content: 'Hello world',
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sig: 'cd4a3cd20dc61dcbc98324de561a07fd23b3d9702115920c0814b5fb822cc5b7c5bcdaf3fa326d24ed50c5b9c8214d66c75bae34e3a84c25e4d122afccb66eb6'
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})
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).toEqual(null)
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expect(
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nip26.getDelegator({
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id: 'a080fd288b60ac2225ff2e2d815291bd730911e583e177302cc949a15dc2b2dc',
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pubkey:
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'62903b1ff41559daf9ee98ef1ae67cc52f301bb5ce26d14baba3052f649c3f49',
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created_at: 1660896109,
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kind: 1,
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tags: [
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[
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'delegation',
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'86f0689bd48dcd19c67a19d994f938ee34f251d8c39976290955ff585f2db42e',
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'kind=1&created_at>1740995200',
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'c33c88ba78ec3c760e49db591ac5f7b129e3887c8af7729795e85a0588007e5ac89b46549232d8f918eefd73e726cb450135314bfda419c030d0b6affe401ec1'
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]
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],
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content: 'Hello world',
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sig: 'cd4a3cd20dc61dcbc98324de561a07fd23b3d9702115920c0814b5fb822cc5b7c5bcdaf3fa326d24ed50c5b9c8214d66c75bae34e3a84c25e4d122afccb66eb6'
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})
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).toEqual(null)
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expect(
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nip26.getDelegator({
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id: 'a080fd288b60ac2225ff2e2d815291bd730911e583e177302cc949a15dc2b2dc',
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pubkey:
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'62903b1ff41559daf9ee98ef1ae67c152f301bb5ce26d14baba3052f649c3f49',
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created_at: 1660896109,
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kind: 1,
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tags: [
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[
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'delegation',
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'86f0689bd48dcd19c67a19d994f938ee34f251d8c39976290955ff585f2db42e',
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'kind=1&created_at>1640995200',
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'c33c88ba78ec3c760e49db591ac5f7b129e3887c8af7729795e85a0588007e5ac89b46549232d8f918eefd73e726cb450135314bfda419c030d0b6affe401ec1'
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]
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],
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content: 'Hello world',
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sig: 'cd4a3cd20dc61dcbc98324de561a07fd23b3d9702115920c0814b5fb822cc5b7c5bcdaf3fa326d24ed50c5b9c8214d66c75bae34e3a84c25e4d122afccb66eb6'
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})
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).toEqual(null)
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})
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test('create and verify delegation', async () => {
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let sk1 = generatePrivateKey()
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let pk1 = getPublicKey(sk1)
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let sk2 = generatePrivateKey()
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let pk2 = getPublicKey(sk2)
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let delegation = nip26.createDelegation(sk1, {pubkey: pk2, kind: 1})
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expect(delegation).toHaveProperty('from', pk1)
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expect(delegation).toHaveProperty('to', pk2)
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expect(delegation).toHaveProperty('cond', 'kind=1')
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let event = {
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kind: 1,
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tags: [['delegation', delegation.from, delegation.cond, delegation.sig]],
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pubkey: pk2
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}
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expect(nip26.getDelegator(event)).toEqual(pk1)
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})

‎nip26.ts

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import * as secp256k1 from '@noble/secp256k1'
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import {sha256} from '@noble/hashes/sha256'
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import {Event} from './event'
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import {utf8Encoder} from './utils'
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import {getPublicKey} from './keys'
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export type Parameters = {
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pubkey: string // the key to whom the delegation will be given
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kind: number | undefined
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until: number | undefined // delegation will only be valid until this date
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since: number | undefined // delegation will be valid from this date on
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}
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export type Delegation = {
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from: string // the pubkey who signed the delegation
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to: string // the pubkey that is allowed to use the delegation
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cond: string // the string of conditions as they should be included in the event tag
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sig: string
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}
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export function createDelegation(
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privateKey: string,
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parameters: Parameters
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): Delegation {
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let conditions = []
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if ((parameters.kind || -1) >= 0) conditions.push(`kind=${parameters.kind}`)
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if (parameters.until) conditions.push(`created_at<${parameters.until}`)
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if (parameters.since) conditions.push(`created_at>${parameters.since}`)
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let cond = conditions.join('&')
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if (cond === '')
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throw new Error('refusing to create a delegation without any conditions')
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let sighash = sha256(
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utf8Encoder.encode(`nostr:delegation:${parameters.pubkey}:${cond}`)
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)
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let sig = secp256k1.utils.bytesToHex(
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secp256k1.schnorr.signSync(sighash, privateKey)
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)
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return {
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from: getPublicKey(privateKey),
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to: parameters.pubkey,
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cond,
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sig
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}
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}
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export function getDelegator(event: Event): string | null {
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// find delegation tag
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let tag = event.tags.find(tag => tag[0] === 'delegation' && tag.length >= 4)
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if (!tag) return null
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let pubkey = tag[1]
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let cond = tag[2]
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let sig = tag[3]
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// check conditions
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let conditions = cond.split('&')
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for (let i = 0; i < conditions.length; i++) {
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let [key, operator, value] = conditions[i].split(/\b/)
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// the supported conditions are just 'kind' and 'created_at' for now
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if (key === 'kind' && operator === '=' && event.kind === parseInt(value))
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continue
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else if (
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key === 'created_at' &&
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operator === '<' &&
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event.created_at < parseInt(value)
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)
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continue
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else if (
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key === 'created_at' &&
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operator === '>' &&
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event.created_at > parseInt(value)
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)
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continue
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else return null // invalid condition
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}
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// check signature
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let sighash = sha256(
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utf8Encoder.encode(`nostr:delegation:${event.pubkey}:${cond}`)
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)
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if (!secp256k1.schnorr.verifySync(sig, sighash, pubkey)) return null
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return pubkey
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}

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