Signing a Windows EXE file

I have an EXE file that I should like to sign so that Windows will not warn the end user about an application from an "unknown publisher". I am not a Windows developer. The application in question is a screensaver generated from an application that generates screensaver applications. As such I have no influence on how the file is generated.

I've already found out that I will need a code signing certificate from a CA like Verisign or instantssl.com. What I don't understand is what I need to do (if at all possible) to sign my EXE file. What is a simple explanation?

Mel Green's answer took me further, but signtool wants me to specify what certificate to use in any case. Can I get a free code signing certificate somehow to test if this will work for me at all?

Also please specify which certificate kind is the correct one. Most sites only mention "code signing" and talk about signing applications that are actually compiled by the user. This is not the case for me.

You can try using Microsoft's Sign Tool

You download it as part of the Windows SDK for Windows Server 2008 and .NET 3.5. Once downloaded you can use it from the command line like so:

> signtool sign /a MyFile.exe

This signs a single executable, using the "best certificate" available. (If you have no certificate, it will show a SignTool error message.)

Or you can try:

> signtool signwizard

This will launch a wizard that will walk you through signing your application. (This option is not available after Windows SDK 7.0.)

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If you'd like to get a hold of certificate that you can use to test your process of signing the executable you can use the .NET tool Makecert.

Certificate Creation Tool (Makecert.exe)

Once you've created your own certificate and have used it to sign your executable, you'll need to manually add it as a Trusted Root CA for your machine in order for UAC to tell the user running it that it's from a trusted source. Important. Installing a certificate as ROOT CA will endanger your users privacy. Look what happened with DELL. You can find more information for accomplishing this both in code and through Windows in:

• Stack Overflow question Install certificates in to the Windows Local user certificate store in C#

• Installing a Self-Signed Certificate as a Trusted Root CA in Windows Vista

Hopefully that provides some more information for anyone attempting to do this!

I had the same scenario in my job and here are our findings

The first thing you have to do is get the certificate and install it on your computer, you can either buy one from a Certificate Authority or generate one using makecert.

Here are the pros and cons of the 2 options

Buy a certificate

• Pros
  • Using a certificate issued by a CA(Certificate Authority) will ensure that Windows will not warn the end user about an application from an "unknown publisher" on any Computer using the certificate from the CA (OS normally comes with the root certificates from manny CA's)
• Cons:

  • There is a cost involved on getting a certificate from a CA

    For prices, see https://cheapsslsecurity.com/sslproducts/codesigningcertificate.html and https://www.digicert.com/code-signing/

Generate a certificate using Makecert

• Pros:
  • The steps are easy and you can share the certificate with the end users
• Cons:
  • End users will have to manually install the certificate on their machines and depending on your clients that might not be an option
  • Certificates generated with makecert are normally used for development and testing, not production

Sign the executable file

There are two ways of signing the file you want:

• Using a certificate installed on the computer

  signtool.exe sign /a /s MY /sha1 sha1_thumbprint_value /t http://timestamp.verisign.com/scripts/timstamp.dll /v "C:\filename.dll"

  • In this example we are using a certificate stored on the Personal folder with a SHA1 thumbprint (This thumbprint comes from the certificate) to sign the file located at C:\filename.dll

• Using a certificate file

  signtool sign /tr http://timestamp.digicert.com /td sha256 /fd sha256 /f "c:\path\to\mycert.pfx" /p pfxpassword "c:\path\to\file.exe"

  • In this example we are using the certificate c:\path\to\mycert.pfx with the password pfxpassword to sign the file c:\path\to\file.exe

Test Your Signature

• Method 1: Using signtool

  Go to: Start > Run
  Type CMD > click OK
  At the command prompt, enter the directory where signtool exists
  Run the following:

  signtool.exe verify /pa /v "C:\filename.dll"

• Method 2: Using Windows

  Right-click the signed file
  Select Properties
  Select the Digital Signatures tab. The signature will be displayed in the Signature list section.

I hope this could help you

Sources:

• https://docs.microsoft.com/en-us/previous-versions/windows/internet-explorer/ie-developer/platform-apis/ms537361(v=vs.85)

• https://www.digicert.com/kb/code-signing/signcode-signtool-command-line.htm

• https://docs.microsoft.com/en-us/windows/win32/seccrypto/makecert

You can get a free cheap code signing certificate from Certum if you're doing open source development.

I've been using their certificate for over a year, and it does get rid of the unknown publisher message from Windows.

As far as signing code I use signtool.exe from a script like this:

signtool.exe sign /t http://timestamp.verisign.com/scripts/timstamp.dll /f "MyCert.pfx" /p MyPassword /d SignedFile.exe SignedFile.exe

The ASP's magazine ASPects has a detailed description on how to sign code (You have to be a member to read the article). You can download it through http://www.asp-shareware.org/

Here's link to a description how you can make your own test certificate.

This might also be interesting.

Another option, if you need to sign the executable on a Linux box is to use signcode from the Mono project tools. It is supported on Ubuntu.

Reference https://steward-fu.github.io/website/driver/wdm/self_sign.htm Note: signtool.exe from Microsoft SDK

1.First time (to make private cert)

Makecert -r -pe -ss YourName YourName.cer

certmgr.exe -add YourName.cer -s -r localMachine root

2.After (to add your sign to your app)

signtool sign /s YourName YourApp.exe

This is not a direct answer to the question, but it is closely related (and useful I hope) since sooner or later any individual programmer will have put his hand into the wallet.

So, prices for EV (Extended Validation) Code Signing Certificates, sorted by price:

AboutSSL
$240/Year (clickbait price)
$287/Year (real price, after coupon)

KSoftware.net
1 Year $350 + ($50 hidden fee!)
2 Year $600
3 Year $750

OV: $84 per year (for 3 years)

I purchased from them an EV. Some years later I purchased an OV. The eToken was sent on a USB stick. No reader needed. They are only intermediary. In the end, you actually purchase from Comodo (Sectigo). Sectigo is veeeeerrry slow. The second time, the verification took two full months. The phone verification failed multiple times. Everything was cumbersome. The tech support didn't have a clue about what is going on, probably just a guy in Pakistan reading through some script.

Sklep.certum.pl
1 Year 379 euro
(seems to be for Poland users only)

LeaderSsl.de
1 Year 364 euro or 307 euro (+19%VAT)
(OV 69+VAT)

Sectigo.com
1 Year $499 USD
3 Year $897 USD

GlobalSign.com
1 Year $410 total
2 Years $760 total
3 Years $950 total

Digicert.com
1 Year: $600 (it was $104)
3 Year: ?

symantec.com
1 Year: $700
3 Years: ridiculous expensive

More prices here:
cheapsslsecurity.com CodeSigning EV
cheapsslsecurity.com SSL only!

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EV vs OV

With EV, nine additional steps are required including verifying a businesses’ public phone number, length of time in business, registration number and jurisdiction, as well as a domain fraud check, contact blacklist check and a telephone call to authenticate the employment status of the requestor.

Some recommend submitting a program signed with OV to Microsoft to be checked with their antivirus.

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IF YOU FIND CHEAPER PRICES, let me know, and I will update the list!

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How to use the certificate?

To sign the exe file, I used MS signtool.exe. For this you will need to download the bloated MS Windows SDK which has a whooping 1GB. FORTUNATELY, you don't have to install it. Just open the ISO and extract "Windows SDK Signing Tools-x86_en-us.msi". It has a merely 400 KB.

Then I built this tiny script file:

prompt $
echo off
cls

copy "my.exe" "my.bak.exe"

"c:\Program Files (x86)\Windows Kits\10\bin\10.0.22000.0\x64\signtool.exe" sign /fd SHA256 /f MyCertificate.pfx /p MyPassword My.exe

pause 

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What happened after signing my EXE file?

So, after investing some money, I finally signed my EXE file. What happened after that? Nothing... On Win10 I still see the same "untrusted" window with the "Don't run" button. The "Continue" button is still invisible. My program has about 400 downloads per day. Let's wait and see how many downloads are necessary.

And yet another option, if you're developing on Windows 10 but don't have Microsoft's signtool.exe installed, you can use Bash on Ubuntu on Windows to sign your app. Here is a run down:

https://blog.synapp.nz/2017/06/16/code-signing-a-windows-application-on-linux-on-windows/

Use following link to sign .exe (setup/ installer)file (sign exe/setup file without using Microsoft setup signtool)

https://ebourg.github.io/jsign/#files

sample command java -jar jsign-2.0.jar --keystore keystore.jks" --alias alias --storepass password MyInstaller.exe

Worked for me :)