Add NIP 55 signer support

packages/signer/package.json

@@ -35,5 +35,8 @@
     "@welshman/net": "0.0.22",
     "@welshman/util": "0.0.33",
     "nostr-tools": "^2.7.2"
+  },
+  "peerDependencies": {
+    "nostr-signer-capacitor-plugin": "github:chebizarro/nostr-signer-capacitor-plugin"
   }
 }

packages/signer/src/index.ts

@@ -3,3 +3,4 @@ export * from './nip59'
 export * from './signers/nip01'
 export * from './signers/nip07'
 export * from './signers/nip46'
+export * from './signers/nip55'

packages/signer/src/signers/nip55.ts

@@ -0,0 +1,143 @@
+import {SignedEvent, StampedEvent} from "@welshman/util"
+import {hash, own, ISigner} from "../util"
+import {NostrSignerPlugin, AppInfo} from "nostr-signer-capacitor-plugin"
+import {nip19} from "nostr-tools"
+
+export const getNip55 = async (): Promise<AppInfo[]> => {
+  const {apps} = await NostrSignerPlugin.getInstalledSignerApps()
+  return apps
+}
+
+export class Nip55Signer implements ISigner {
+  #lock = Promise.resolve()
+  #plugin = NostrSignerPlugin
+  #packageName: string
+  #packageNameSet = false
+  #npub?: string
+  #publicKey?: string
+
+  constructor(packageName: string) {
+    this.#packageName = packageName
+    this.#initialize()
+  }
+
+  async #initialize() {
+    if (!this.#packageNameSet) {
+      await this.#plugin.setPackageName({packageName: this.#packageName})
+      this.#packageNameSet = true
+    }
+  }
+
+  #then = async <T>(f: (signer: typeof NostrSignerPlugin) => T | Promise<T>): Promise<T> => {
+    const promise = this.#lock.then(async () => {
+      if (!this.#packageNameSet) {
+        try {
+          await this.#plugin.setPackageName({packageName: this.#packageName})
+          this.#packageNameSet = true
+        } catch (error) {
+          this.#packageNameSet = false
+          throw error
+        }
+      }
+      return f(this.#plugin)
+    })
+
+    this.#lock = promise.then(() => Promise.resolve())
+
+    return promise
+  }
+
+  getPubkey = async (): Promise<string> => {
+    return this.#then(async signer => {
+      if (!this.#publicKey || !this.#npub) {
+        try {
+          const {npub} = await signer.getPublicKey()
+          this.#npub = npub
+          const {data} = nip19.decode(npub)
+          this.#publicKey = data as string
+        } catch (error) {
+          throw new Error(`Failed to get public key`)
+        }
+      }
+      return this.#publicKey
+    })
+  }
+
+  sign = async (template: StampedEvent): Promise<SignedEvent> => {
+    const pubkey = await this.getPubkey() // hex-encoded public key
+    const npub = this.#npub! // Bech32-encoded public key
+    const event = {sig: "", ...hash(own(template, pubkey))}
+
+    return this.#then(async signer => {
+      const {event: signedEventJson} = await signer.signEvent({
+        eventJson: JSON.stringify(event),
+        eventId: event.id,
+        npub: npub,
+      })
+      const signedEvent = JSON.parse(signedEventJson) as SignedEvent
+      return signedEvent
+    })
+  }
+
+  nip04 = {
+    encrypt: async (recipientPubKey: string, message: string): Promise<string> => {
+      const myNpub = this.#npub
+      if (!myNpub) {
+        await this.getPubkey()
+      }
+      return this.#then(async signer => {
+        const {result} = await signer.nip04Encrypt({
+          pubKey: recipientPubKey,
+          plainText: message,
+          npub: this.#npub!,
+        })
+        return result
+      })
+    },
+    decrypt: async (senderPubKey: string, message: string): Promise<string> => {
+      const myNpub = this.#npub
+      if (!myNpub) {
+        await this.getPubkey()
+      }
+      return this.#then(async signer => {
+        const {result} = await signer.nip04Decrypt({
+          pubKey: senderPubKey,
+          encryptedText: message,
+          npub: this.#npub!,
+        })
+        return result
+      })
+    },
+  }
+
+  nip44 = {
+    encrypt: async (recipientPubKey: string, message: string): Promise<string> => {
+      const myNpub = this.#npub
+      if (!myNpub) {
+        await this.getPubkey()
+      }
+      return this.#then(async signer => {
+        const {result} = await signer.nip44Encrypt({
+          pubKey: recipientPubKey,
+          plainText: message,
+          npub: this.#npub!,
+        })
+        return result
+      })
+    },
+    decrypt: async (senderPubKey: string, message: string): Promise<string> => {
+      const myNpub = this.#npub
+      if (!myNpub) {
+        await this.getPubkey()
+      }
+      return this.#then(async signer => {
+        const {result} = await signer.nip44Decrypt({
+          pubKey: senderPubKey,
+          encryptedText: message,
+          npub: this.#npub!,
+        })
+        return result
+      })
+    },
+  }
+}