fix(ios): remove double auth issue (#3)

Signed-off-by: Berend Sliedrecht <[email protected]>

ios/ExpoSecureEnvironmentModule.swift

@@ -13,8 +13,8 @@ public class ExpoSecureEnvironmentModule: Module {
     }
 
     AsyncFunction("sign") {
-      (id: String, message: Data, biometricsBacked: Bool) async throws -> Data in
-      return try await SecureEnvironment.sign(id, message, biometricsBacked)
+      (id: String, message: Data) async throws -> Data in
+      return try await SecureEnvironment.sign(id, message)
     }
   }
 }

ios/SecureEnvironment.swift

@@ -55,18 +55,8 @@ struct SecureEnvironment {
     return compressPublicKey(data)
   }
 
-  static func sign(_ keyId: String, _ message: Data, _ biometricsBacked: Bool) async throws -> Data
+  static func sign(_ keyId: String, _ message: Data) async throws -> Data
   {
-    if biometricsBacked {
-      let status = try await LAContext().evaluatePolicy(
-        .deviceOwnerAuthenticationWithBiometrics,
-        localizedReason: "Access signer key to sign a message")
-
-      guard status else {
-        throw SecureEnvironmentError.BiometricAuthenticationFailed
-      }
-    }
-
     let key = try getKeyFromKeychainById(keyId)
     var error: Unmanaged<CFError>?
     guard

src/index.ts

@@ -24,7 +24,15 @@ export async function sign(
   message: Uint8Array,
   biometricsBacked: boolean = true
 ): Promise<Uint8Array> {
-  const signature = await ExpoSecureEnvironmentModule.sign(keyId, message, biometricsBacked);
+  const signature =
+    Platform.OS === "ios"
+      ? await ExpoSecureEnvironmentModule.sign(keyId, message)
+      : await ExpoSecureEnvironmentModule.sign(
+          keyId,
+          message,
+          biometricsBacked,
+          biometricsBacked
+        );
 
   const { r, s } = AsnParser.parse(signature, ECDSASigValue);
   const newR = new Uint8Array(r.byteLength === 33 ? r.slice(1) : r);