support NIP-57

package-lock.json

@@ -1534,6 +1534,11 @@
         }
       }
     },
+    "@noble/secp256k1": {
+      "version": "1.7.1",
+      "resolved": "https://registry.npmjs.org/@noble/secp256k1/-/secp256k1-1.7.1.tgz",
+      "integrity": "sha512-hOUk6AyBFmqVrv7k5WAw/LpszxVbj9gGN4JRkIX52fdFAj1UA61KXmZDvqVEm+pOyec3+fIeZB02LYa/pWOArw=="
+    },
     "@opensearch-project/opensearch": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/@opensearch-project/opensearch/-/opensearch-1.1.0.tgz",

package.json

@@ -11,6 +11,7 @@
   "dependencies": {
     "@apollo/client": "^3.7.1",
     "@lexical/react": "^0.7.5",
+    "@noble/secp256k1": "^1.7.1",
     "@opensearch-project/opensearch": "^1.1.0",
     "@prisma/client": "^2.30.3",
     "@synonymdev/slashtags-auth": "^1.0.0-alpha.5",

pages/api/lnurlp/[username]/index.js

@@ -7,11 +7,20 @@ export default async ({ query: { username } }, res) => {
     return res.status(400).json({ status: 'ERROR', reason: `user @${username} does not exist` })
   }
 
+  let nostr = {}
+  if (user.nostrPubkey) {
+    nostr = {
+      nostrPubkey: user.nostrPubkey,
+      allowsNostr: true
+    }
+  }
+
   return res.status(200).json({
     callback: `${process.env.PUBLIC_URL}/api/lnurlp/${username}/pay`, // The URL from LN SERVICE which will accept the pay request parameters
     minSendable: 1000, // Min amount LN SERVICE is willing to receive, can not be less than 1 or more than `maxSendable`
     maxSendable: 1000000000,
     metadata: lnurlPayMetadataString(username), // Metadata json which must be presented as raw string here, this is required to pass signature verification at a later step
-    tag: 'payRequest' // Type of LNURL
+    tag: 'payRequest', // Type of LNURL
+    ...nostr
   })
 }

pages/api/lnurlp/[username]/pay.js

@@ -3,24 +3,43 @@ import lnd from '../../../../api/lnd'
 import { createInvoice } from 'ln-service'
 import { lnurlPayDescriptionHashForUser } from '../../../../lib/lnurl'
 import serialize from '../../../../api/resolvers/serial'
+import * as secp256k1 from '@noble/secp256k1'
+import { createHash } from 'crypto'
 
-export default async ({ query: { username, amount } }, res) => {
+export default async ({ query: { username, amount, nostr } }, res) => {
   const user = await models.user.findUnique({ where: { name: username } })
   if (!user) {
     return res.status(400).json({ status: 'ERROR', reason: `user @${username} does not exist` })
   }
-
-  if (!amount || amount < 1000) {
-    return res.status(400).json({ status: 'ERROR', reason: 'amount must be >=1000 msats' })
-  }
-
-  // generate invoice
-  const expiresAt = new Date(new Date().setMinutes(new Date().getMinutes() + 1))
-  const description = `${amount} msats for @${user.name} on stacker.news`
-  const descriptionHash = lnurlPayDescriptionHashForUser(username)
   try {
+  // if nostr, decode, validate sig, check tags, set description hash
+    let description, descriptionHash
+    if (nostr) {
+      const noteStr = decodeURI(nostr)
+      const note = JSON.parse(noteStr)
+      const hasPTag = note.tags?.filter(t => t[0] === 'p').length >= 1
+      const hasETag = note.tags?.filter(t => t[0] === 'e').length <= 1
+      if (await secp256k1.schnorr.verify(note.sig, note.id, note.pubkey) &&
+      hasPTag && hasETag) {
+        description = user.hideInvoiceDesc ? undefined : `${amount} msats for @${user.name} on stacker.news via NIP-57`
+        descriptionHash = createHash('sha256').update(noteStr).digest('hex')
+      } else {
+        res.status(400).json({ status: 'ERROR', reason: 'invalid NIP-57 note' })
+        return
+      }
+    } else {
+      description = user.hideInvoiceDesc ? undefined : `${amount} msats for @${user.name} on stacker.news`
+      descriptionHash = lnurlPayDescriptionHashForUser(username)
+    }
+
+    if (!amount || amount < 1000) {
+      return res.status(400).json({ status: 'ERROR', reason: 'amount must be >=1000 msats' })
+    }
+
+    // generate invoice
+    const expiresAt = new Date(new Date().setMinutes(new Date().getMinutes() + 1))
     const invoice = await createInvoice({
-      description: user.hideInvoiceDesc ? undefined : description,
+      description: description,
       description_hash: descriptionHash,
       lnd,
       mtokens: amount,