[bug] Can not use empty string as the password of signing private key

[xuanzhi33]

Describe the bug

If I do not set a password (using an empty string), it will output `incorrect updater private key password: Wrong password for that key` when signing files.

Reproduction

pnpm create tauri-app
pnpm tauri signer generate -w test.key -p "" 
pnpm tauri signer sign -f test.key README.md -p ""

it will output incorrect updater private key password: Wrong password for that key on Windows, macOS, and Linux.

Expected behavior

No response

Full tauri info output

➜  test1 git:(main) ✗ pnpm tauri info                                    

> test1@0.1.0 tauri /workspace/test1
> tauri info


[✘] Environment
    - OS: Debian 12.0.0 x86_64 (X64) (Unknown DE on Unknown Session)
    ✘ webkit2gtk-4.1: not installed
      Visit https://v2.tauri.app/start/prerequisites/ to learn more about tauri prerequisites
    ✘ rsvg2: not installed
      Visit https://v2.tauri.app/start/prerequisites/ to learn more about tauri prerequisites
    ✔ rustc: 1.92.0 (ded5c06cf 2025-12-08)
    ✔ cargo: 1.92.0 (344c4567c 2025-10-21)
    ✔ rustup: 1.28.2 (e4f3ad6f8 2025-04-28)
    ✔ Rust toolchain: stable-x86_64-unknown-linux-gnu (default)
    - node: 22.21.1
    - pnpm: 10.26.0
    - npm: 10.9.4

[-] Packages
    - tauri 🦀: 2
    - tauri-build 🦀: No version detected
    - wry 🦀: No version detected
    - tao 🦀: No version detected
    - @tauri-apps/api  ⱼₛ: 2.9.1
    - @tauri-apps/cli  ⱼₛ: 2.9.6

[-] Plugins
    - tauri-plugin-opener 🦀: 2
    - @tauri-apps/plugin-opener  ⱼₛ: 2.5.3

[-] App
    - build-type: bundle
    - CSP: unset
    - frontendDist: ../dist
    - devUrl: http://localhost:1420/
    - framework: Vue.js
    - bundler: Vite

Stack trace

Additional context

No response

[xuanzhi33]

I also found someone else experiencing the same issue in the comments of another issue.

pnpm tauri signer generate -p ""

is also not working which I think should generate a keypair without a password.

pnpm tauri signer generate -p "somepassword"

only signing with some password makes it work. I am not sure if this is only a Mac issue or only an issue on my Mac. I will do some other tests to locate the problem.

Originally posted by @Fanzzzd in #13485