Code Signing with a Certum certificate - windows

I want to sign a static .exe build of one of my Open Source programs so that it will be executable in a "normal" manner to a "normal" Windows user.
I bought an Open Source Code Signing Certificate from certum.eu to be able to do this.
After some searching on the internet, I tried to sign the exe file using osslsigncode 1.7.1 on my Linux maching using
osslsigncode sign -pkcs12 cert.p12 -pass "..." -h sha2 -t http://timestamp.verisign.com/scripts/timstamp.dll -in some.exe -out some-signed.exe
Having somebody testing it on Windows 10, a rough warning pops up: "Windows protected your PC. Windows SmartScreen prevented an unrecognized app
from starting. Running this app might put your PC at risk."
So I tried to use the native Windows tool signtool.exe to sign it. I installed it in my old virtual Windows XP (where I also compiled the program; I don't have access to any other Windows machine) and signed the exe file with
"C:\Programme\Microsoft SDKs\Windows\v7.1\Bin\signtool.exe" sign /f C:\cert.p12 /p "..." /t http://timestamp.verisign.com/scripts/timstamp.dll C:\some.exe
This tool also said everything was okay, but still, the very same warning pops up.
This way, the certificate is simply useless, as the "signed" exe file does produce the very same warning as the unsigned one. I would greatly appreciate help about this.

Short answer: Wait a couple of days and the problem will disappear.
I had the same issue with my Certum certificate earlier this year. And a few years ago, I had a commercial certificate I got from Comodo and it initially had the same issue as well.
The bottom line is that your new certificate and signed binaries needs some time to gain trust and auto-verified by Microsoft's code-signing reputation service.
Start distributing your signed exe to as many PC as you can and do the "advanced" option to force the exe to run anyway. That might help bump the reputation up faster.

Related

Windows 10 ignores Authenticode on my setups files

Being on the "Fast Ring" of Windows 10, I got a strange behaviour on my own setup executables:
I'm SHA-1 signing them with Authenticode since years the same way and never had any problems.
Recently Windows 10 does not recognize my (valid) signatures.
When downloading a setup.exe from my website and executing it, the Windows SmartScreen message box appears and tells me:
...
Publisher: unknown
...
When viewing the properties of the just downloaded setup executable, it shows the signature, and tells me that the signature is valid.
In addition, the whole certificate chain is valid.
I'm signing it with something like this:
SignTool.exe sign /v /t http://timestamp.verisign.com/scripts/timstamp.dll
/f "my-authenticode.pfx" /p "my-password" "my-setup.exe"
(Line-breaks added for readability)
My question:
Is anyone aware of a possible reason (and fix) for this?
More Information:
I can think of possible reasons:
Signing with Windows 10 Fast Ring is buggy. (I've signed on Windows Server 2008 R2 with the same behaviour).
Running the downloaded setup executable within Windows 10 Fast Ring is buggy.
Update 1:
I've found a MSDN blog article back from 2013 that seems to talk about something similar as I discover, but I still cannot see whether this really applies.
More strange: Older downloads from our website, signed with the same Authenticode certificate do not trigger the warning.
Maybe SmartScreen compares the timestamp and behaves differently for newer signatures/setup executables?
Maybe I would need to add additional/different parameters when calling SignTool.exe?
Update 2:
On a non-Fast Ring Windows 10, the SmartScreen warning is not displayed.
In addition, there is also a similar SO posting which didn't help me further.
Plus, there is a Symantec posting, that claims:
For Windows Vista 64-bit and Windows 7 the signing process has changed. The code cannot simply be signed, it also needs to be "cross-signed" with a certificate provided by Microsoft.
This is strange to me since my signing procedure worked successfully until recently.
They further link to their own instructions which talk about kernel mode software only.
Update 3:
User GSerg pointed me to "Windows Enforcement of Authenticode Code Signing and Timestamping" on Microsoft TechNet.
This seems to go into the right direction.
I've seen that my current certificate is SHA-1. I've just updated it to SHA-2/SHA-256 by re-issuing it from Thawte.
Now, I still get a SmartScreen warning on my local Windows 10 Fast Ring PC but at least it now prints the publisher.
I'll no purchase a code signing cert from DigiCert since I believe that the certificate chain also has influence on how the SmartScreen filter sees my application. I do hope it is an improvement compared to the Thawte certificate I'm currently using.
If you plan to sign for Windows Vista, please note that there was a problem with SHA-256 signed files. The linked TechNet article talks about dual signing to overcome this.
Update 4:
See also this SO answer that deals about passing the SmartScreen warning with signed applications.
If this DigiCert certificate plus waiting to get enough reputation still does not help, I'll probably have to swallow the bitter pill and buy an extended validation (EV) code signing certificate (which requires a hardware token and is more expensive).
Update 5:
After approx. one day, SmartScreen seems to not show any warnings anymore.
Seems that my now dual-signed setup executables (SHA-1 plus SHA-256) already got enough reputation to successfully pass the SmartScreen tests.
My certification path/chain now looks like this:
What looks a bit strange to me is that the root certificate "thawte" still uses SHA-1.
I would have expected that this still causes SmartScreen worries, but it seems it doesn't.
Update 6:
The article "Do You Need SHA-2 Signed Root Certificates?" explains why you do not need a SHA-256 root certificate.
In the meantime I've also received my Authenticode certificate from DigiCert. I'm using it in some setups already.
It only took about one single day until the SmartScreen filter did pick it up and not warn about it anymore.
So I'm now having a Thawte Authenticode code signing certificate and a DigiCert Authenticode code signing certificate.
If I understood the SHA-256 implications earlier, I could have saved the money for the DigiCert certificate.
As user GSerg pointed out, the reason for the error in my initial question was that I'm using SHA-1 only which is "deprecated" by Microsoft since 2016.
After dual-signing my setup executable both with SHA-1 and SHA-256 (and waiting some days), the SmartScreen filter does not complain anymore.

Microsoft SmartScreen - suspended using Inno Setup installer?

I always use Inno Setup for packaging and publishing. Users download the application using a link for example: https://oursite.com/codesigned/mysetup.exe
Till now, it always worked. But recently I have to renew my code signing certificate because its expired. After renew I have SmartScreen problem, every users download the application and gets this Smartscreen which was not before.
I have used signtool.exe verify /pa innosetup-made-myexe.exe and it shows successful, also I have done the verification with Windows Application Certification Kit, that shows it is PASSED, but with WARNNINGS, all those WARNNINGS mostly generated by Inno Setup.
Here you can find the output, where its showing WARNINGS on Inno Setup exes:
https://docs.google.com/document/d/11frW_GxI0xSVcrAXh4_rqcKBQSaermAlpYKj4xzQi4o/pub
How can I fix this problem?
(still not sure if its Standard Code Signing vs EV code signing issue? I already used Standard Code Signing for few years, it always worked. I can upgrade to EV Code signing, but how can I make sure its not Inno Setup compiler problem? As you can see already the WARNNINGS are shown in the URL above to Inno Setup)
To verify if it's Inno Setup or code signing issue (see https://stackoverflow.com/a/29067585/285594), I have done following:
From Microsoft, I have downloaded the file call winqual.exe, which does not need Inno Setup.
I code signed the winqual.exe and uploaded to my same server
I downloaded the same file with Internet Explorer and it works without showing me the SmartScreen.
Does it make any sense now if Inno Setup is the main cause of this problem?
Nowadays, you have to use EV code signing certificates.
See Transferring Microsoft SmartScreen reputation to renewed certificate.
Below is the original answer, which addresses some specifics of the question.
If you believe the problem is due to an unsigned uninstaller, make sure you set the SignTool directive of your Inno Setup project accordingly. And make sure SignedUninstaller directive has its default value yes.
Quoting SignTool directive documentation:
Specifies the name and parameters of the Sign Tool to be used to digitally sign Setup (and Uninstall if SignedUninstaller is set to yes). When Setup has a valid digital signature, users will not see an "unidentified program" warning when launching it.
If you want to set NXCOMPAT and DYNAMICBASE flags to the uninstaller, you can create a sign.bat batch file that both calls signtool.exe and editbin.exe:
#echo off
editbin.exe /NXCOMPAT /DYNAMICBASE %1
signtool.exe sign ... %1
The calls need to be in this order, otherwise the editbin.exe breaks the signature.
Then use the sign.bat instead of signtool.exe in the SignTool directive.
Though I do not really think this is necessary, nor helps anything.
I think this is normal behavior.
When your software collect enough "likes" = downloads or installs the SmrtScreen will automatically turn off this message.
It is really annoying feature because with every software release you need to wait appropriate time while the software become "popular" and it is recognized as safe (no certificates or antivirus methods can solve it).
You do NOT need this "Windows Application Certification Kit".
What #slappy says is correct:
After renewal of your certificate, you need enough downloads and "good reviews" before this message goes away.
What you need to do is to download your application using Microsoft Edge (not Chrome or Firefox!!!).
It will most likely say "This download may be dangerous and has been blocked".
Then you can choose "Keep anyways". And then you can choose "Report as Secure".
And THEN even Smart Screen says that it doesn't trust your app (even though it's digitally signed, LOL!!!!), then you have to choose "More..." and "Install anyways".
Install it on your computer! I think that is important.
I have used 5 different computers and reported my apps as secure multiple times and installed it.
I have also asked 2 friends (because of their different IP address) to do the same.
I hate this so much!!!!!!!!!!
After 1 day, the error message was gone.

Kernel mode code signing

I made a driver, and now I need to sign it. It runs in kernel mode.
From what I've read in Microsoft's Kernel Mode Code Signing Walkthrough, I have to buy a software publisher certificate from a commercial CA. In that document, they say to look at the end, and follow this link for a list of CAs from which I can buy that certificate. I find the link very confusing somehow because I can't figure out exactly what certificate I need to buy. I need to sign the driver so that it will install on 64-bit Windows systems. A direct link would be very welcome (I would like to buy it from GlobalSign).
Is it the Microsoft Authenticode from here?
I asked a similar question in Microsoft Drivers Developers Forum some time ago. This is their answer:
You need to have your company get a code signing certificate from either GlobalSign or VeriSign (the others listed in that link are no longer offered). GlobalSign is cheaper, but Verisign has the advantage of providing access to WHQL if that is of interest to your firm. These are not cheap, the Verisign certificate costs $499 per year. Once you have
the cert you can use it instead of the test cert to sign the driver.
Your link contains this information in Supported Platforms: Digitally sign Windows ActiveX controls via Authenticode (32 bit and 64 bit .exe, .ocx, .dll or other) and kernel software for Windows. Windows 7 compatible.
It looks like you are in the right place.
Just to be precise: I have not used the code certification yet, I just learned it. I recommend you to verify this answer in osronline or Microsoft Drivers Developers Forum.
Check out https://www.startssl.com/?app=40 - StartSSL offers such certificates for US$ 199.00
The cross-signed CA certificate is at https://www.startssl.com/certs/ named microsoft.kernel.mode.pem or microsoft.kernel.mode.crt
You can buy a signature from Digicert.
Digicert will issue a cross signing certificate in a zip file. Unzip it
DigiCert High Assurance EV Root CA.crt
Double click it and add it to your IE personal store
Using IE, export the cert, with password to a .pfx file
The command to sign the driver is
signtool sign /t http://timestamp.digicert.com /f "path to .pfx file" /p PASSWORD_OF_PFX "path to driver .cat file"
You can use this same command to sign .exe files
signtool sign /t http://timestamp.digicert.com /f "path to .pfx file" /p PASSWORD_OF_PFX "path to driver .exe file"
Ensure this machine has internet access otherwise the signing process will fail.

How do I sign exes and dlls with my code signing certificate

(I purchased a code signing cert from Thawte and have been going out of my mind with frustration at the whole process.
What I have from them are:
.spc / .p7b file
.pvk file
(NOTE I do not have a pfx file from them. God knows why, but I have been fighting with their tech support for a week)
In any case I find "help" links on their site and at MS for signcode.exe which is useless for me because I can't find that exe on my machine, however I do have signtool.exe.
Unfortunately i am mystified at the command line parameters listed on this MS help site.
Specifically, what parameters do I use and what values? I tried what I thought was obvious but it does not work at all.
I can get the signing wizard to work, however I need this to work non-interactively in a hudson CI batch file.
It really doesn't seem like it should be this difficult, but so far it is all black magic.
thanks for any help
First, you can generate your own pfx file using the pvk2pfx tool described at http://msdn.microsoft.com/en-us/library/ff549703(VS.85).aspx
Something like
pvk2pfx -pvk cert.pvk -spc cert.spc -pfx cert.pfx -pi password
ought to do the trick.
Secondly, signtool is the tool you're after. http://msdn.microsoft.com/en-us/library/aa387764(VS.85).aspx
signtool sign /?
Gets you the help, but the basic command you're probably after is
signtool sign /f cert.pfx /p password target.exe
Which will sign target.exe. It gets more complex if you want to put the certificate into the certificate store on the machine (this is the CSP bit). This is really useful though for doing signing on a lot of dev machines, or on build lab machines where you want to avoid putting the certificate in source control.

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.
How to sign your app
Use Microsoft's SignTool to sign your app.
You download it as part of the Windows SDK. Note that it's also possible to install SignTool without installing the entire SDK. Once installed you can use SignTool from the command line like so:
signtool sign /a /fd SHA256 /tr http://timestamp.digicert.com /td SHA256 MyFile.exe
This will sign MyFile.exe. Explanation of the used command line options:
/a will automatically use the certificate that is valid for the longest time. If you have no certificate, SignTool will display an error.
/fd SHA256 will use the SHA-256 digest algorithm for the file signature. Using SHA256 is recommended and considered to be more secure than the default SHA1 digest algorithm.
/tr http://timestamp.digicert.com adds a timestamp to your signed apps. This is extremely important because this will allow the signature to remain valid even after the certificate itself has already expired. The argument for the /tr option is a timestamp URL. You can use any of the timestamp URL's from this list of free RFC 3161 timestamp servers.
/td SHA256 will use the SHA-256 digest algorithm for the timestamp signature. As before, using SHA256 is recommended and considered to be more secure.
How and when to use self-signed certificates
If you'd like to get a hold of a certificate that you can use to test your process of signing the executable, you can use MakeCert to create a self-signed certificate.
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 accept your self-signed certificate as a trusted source. Note that you can only do this on your own development machines. You usually can not do this on your user's computers, since most users will not accept to install a new Root CA for good reasons.
How to get rid of the "unrecognized app" warning
Even if your app is signed, you might still see the following warning message when trying to run the app:
Microsoft Defender SmartScreen prevented an unrecognized app from
starting. Running this app might put your PC at risk.
How to avoid this warning is a somewhat complex topic. Please see this answer to get the whole picture about these Microsoft SmartScreen warnings and what you can do and should know about it.
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://learn.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://learn.microsoft.com/en-us/windows/win32/seccrypto/makecert
https://cheapsslweb.com/comodo-code-signing
You can get a 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. Price history:
2005 - €14.00
2019 - €25.00
2022 - €69.00
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
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.
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.
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!
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.
IF YOU FIND CHEAPER PRICES, let me know, and I will update the list!
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
__
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.
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
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 :)

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