script is not digitally signed powershell

2 min read 03-10-2024

script is not digitally signed powershell

# Understanding the "Script is not Digitally Signed" Error in PowerShell

When working with PowerShell, you may encounter the error message: **"Script is not digitally signed."** This issue arises when you try to execute a script that lacks a digital signature, which is essential for verifying the script's integrity and source. 

## Original Scenario and Code

Here’s a simple example of a PowerShell script that could trigger this error:

```powershell
Get-Process | Where-Object { $_.CPU -gt 100 }

When you run the script above in an environment that enforces script signing, you might see the error:

File C:\path\to\your\script.ps1 is not digitally signed.

Analyzing the Issue

This error is primarily related to PowerShell's execution policies, which are designed to prevent the execution of potentially harmful scripts. By default, the Restricted execution policy does not allow any scripts to run unless they are signed.

Common Execution Policies:

Restricted: No scripts can be run.
AllSigned: Only scripts signed by a trusted publisher can be run.
RemoteSigned: Scripts created locally do not need to be signed, but scripts downloaded from the internet must be signed.
Unrestricted: All scripts can be run regardless of their source.

If you're encountering the "Script is not digitally signed" error, it likely means you're working with an execution policy set to AllSigned or RemoteSigned.

Solutions to the Problem

Here are a few methods to resolve this error:

Sign the Script: The most secure approach is to digitally sign your script using a trusted certificate. This ensures the authenticity and integrity of your script.
Change the Execution Policy: You can change the execution policy to allow scripts to run without a digital signature. Open PowerShell as an administrator and run:
```
Set-ExecutionPolicy RemoteSigned
```
Note: Always be cautious with execution policies as lowering security can expose your system to risks.
Bypass Execution Policy for a Single Session: If you only need to run the script for a single session without changing the execution policy permanently, you can use:
```
powershell -ExecutionPolicy Bypass -File "C:\path\to\your\script.ps1"
```

Practical Example

Let’s say you frequently run a script that checks for high CPU usage. Here’s how to run it with a bypass if you don’t want to permanently change your execution policy:

powershell -ExecutionPolicy Bypass -File "C:\Scripts\CheckHighCPU.ps1"

This command allows you to execute the script without modifying the current execution policy settings.

Conclusion

The "Script is not digitally signed" error in PowerShell can hinder your productivity, but understanding the underlying cause helps you to navigate around it effectively. By either signing your scripts or adjusting your execution policy, you can execute PowerShell scripts securely and efficiently.

Useful Resources

By following the insights in this article, you can efficiently tackle the digital signing issue in PowerShell and enhance your script-running experience.