feat(core): Signer.fromSignature

Author: Hanssen0

.changeset/fifty-planes-fetch.md

@@ -0,0 +1,6 @@
+---
+"@ckb-ccc/core": minor
+---
+
+feat(core): `Signer.fromSignature`
+  

packages/core/src/signer/index.ts

@@ -5,3 +5,22 @@ export * from "./dummy/index.js";
 export * from "./evm/index.js";
 export * from "./nostr/index.js";
 export * from "./signer/index.js";
+export * from "./signerFromSignature.js";
+
+import { BytesLike } from "../bytes/index.js";
+import { Client } from "../client/index.js";
+import { Signature, Signer } from "./signer/index.js";
+import { signerFromSignature } from "./signerFromSignature.js";
+
+export abstract class CompletedSigner extends Signer {
+  static fromSignature(
+    client: Client,
+    signature: Signature,
+    message?: string | BytesLike | null,
+    ...addresses: (string | string[])[]
+  ): Promise<Signer | undefined> {
+    return signerFromSignature(client, signature, message, ...addresses);
+  }
+}
+
+export { CompletedSigner as Signer };

packages/core/src/signer/signer/index.ts

@@ -157,6 +157,17 @@ export abstract class Signer {
     }
   }
 
+  static async fromSignature(
+    _client: Client,
+    _signature: Signature,
+    _message?: string | BytesLike | null,
+    ..._addresses: (string | string[])[]
+  ): Promise<Signer | undefined> {
+    throw Error(
+      "Signer.fromSignature should be override to avoid circular references",
+    );
+  }
+
   /**
    * Connects to the signer.
    *

packages/core/src/signer/signerFromSignature.ts

@@ -0,0 +1,65 @@
+import { Address } from "../address/index.js";
+import { BytesLike } from "../bytes/index.js";
+import { Client } from "../client/index.js";
+import { SignerBtcPublicKeyReadonly } from "./btc/index.js";
+import { SignerCkbPublicKey, SignerCkbScriptReadonly } from "./ckb/index.js";
+import { SignerDogeAddressReadonly } from "./doge/index.js";
+import { SignerEvmAddressReadonly } from "./evm/index.js";
+import { SignerNostrPublicKeyReadonly } from "./nostr/index.js";
+import { Signature, Signer, SignerSignType } from "./signer/index.js";
+
+/**
+ * Creates a signer from a signature.
+ *
+ * @param client - The client instance.
+ * @param signature - The signature to create the signer from.
+ * @param message - The message that was signed.
+ * @param addresses - The addresses to check against the signer.
+ * @returns The signer if the signature is valid and the addresses match, otherwise undefined.
+ * @throws Error if the signature sign type is unknown.
+ */
+export async function signerFromSignature(
+  client: Client,
+  signature: Signature,
+  message?: string | BytesLike | null,
+  ...addresses: (string | string[])[]
+): Promise<Signer | undefined> {
+  if (
+    message != undefined &&
+    !(await Signer.verifyMessage(message, signature))
+  ) {
+    return;
+  }
+
+  const signer = await (async () => {
+    switch (signature.signType) {
+      case SignerSignType.EvmPersonal:
+        return new SignerEvmAddressReadonly(client, signature.identity);
+      case SignerSignType.BtcEcdsa:
+        return new SignerBtcPublicKeyReadonly(client, "", signature.identity);
+      case SignerSignType.JoyId: {
+        const { address } = JSON.parse(signature.identity) as {
+          address: string;
+        };
+        return new SignerCkbScriptReadonly(
+          client,
+          (await Address.fromString(address, client)).script,
+        );
+      }
+      case SignerSignType.NostrEvent:
+        return new SignerNostrPublicKeyReadonly(client, signature.identity);
+      case SignerSignType.CkbSecp256k1:
+        return new SignerCkbPublicKey(client, signature.identity);
+      case SignerSignType.DogeEcdsa:
+        return new SignerDogeAddressReadonly(client, signature.identity);
+      case SignerSignType.Unknown:
+        throw new Error("Unknown signer sign type");
+    }
+  })();
+  const signerAddresses = await signer.getAddresses();
+  if (!addresses.flat().every((addr) => signerAddresses.includes(addr))) {
+    return;
+  }
+
+  return signer;
+}