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Questions tagged [signature]

120 questions
60
votes
14 answers

How do I digitally sign a PDF with a S/MIME certificate?

I have already acquired a S/MIME certificate (a .p12 file) issued by an authority. Using it in Writer, I can digitally sign documents by following this procedure : How do I make a digital certificate available to LibreOffice Writer for digital…
Agmenor
  • 16,394
56
votes
1 answer

Invalid signature from repo.skype.com: how can I clear this?

Today I did sudo apt upgrade and then, as a double-check, did sudo apt update. The latter terminated with: Hit:5 http://dl.google.com/linux/chrome/deb stable InRelease Get:6 https://repo.skype.com/deb stable…
James E Keenan
  • 935
50
votes
4 answers

Google Chrome PPA upgrade invalid signature

When running: sudo apt-get update && sudo apt-get dist-upgrade I got this output: Ign http://security.ubuntu.com utopic-security InRelease Ign http://gb.archive.ubuntu.com utopic InRelease Ign http://extras.ubuntu.com…
user364819
27
votes
1 answer

How can I validate a pdf's digital signature with evince?

A while ago I received a PDF file that was digitally signed. The Document Viewer (Evince) shows me that the digital signature was not validated. How do I add the file's digital signature to evince so that the warning disappears?
jorgehsrama
  • 706
24
votes
2 answers

Why isn't `apt upgrade` getting a new software key signature for skype?

After a recent apt update && apt full-upgrade I started getting the following error when running apt full-upgrade subsequently: Get:4 https://repo.skype.com/deb stable InRelease [4,502 B] Err:4…
Broadsworde
  • 4,532
20
votes
2 answers

Signature-based rootkit scanner?

Currently the only rootkit scanners I know of have to be installed on the machine before the rootkit so that they can compare file changes etc (e.g.: chkrootkit and rkhunter), but what I really need to do is to be able to scan my machine and other…
user364819
19
votes
2 answers

Does linux have a signature system for executables?

Windows has a signature system which allows you to make sure that an executable hasn't been modified after it has been signed. I used to use this as a security measure in Windows. Does linux have such a system which allows developers to put…
Ufoguy
  • 1,268
19
votes
4 answers

How do I make a digital certificate available to LibreOffice Writer for digital signatures?

I obtained a client certificate from CAcert through Firefox. I want to use that certificate to sign a document created with LibreOffice Writer. In Writer, I click File > Digital Signatures... to get the Digital Signatures dialog which is supposed to…
Geoffrey
  • 445
18
votes
2 answers

How to sign files with Ubuntu command-line tools and my own keys?

I want to sign some Python code files I wrote, because they are plug-in modules for one of my projects. For distributing it, I want that the user can be sure a plug-in is verified and safe (because written by me or somebody I trust) and was not…
Byte Commander
  • 110,243
16
votes
2 answers

how do you create a "signed" deb package

I want to create a number of deb packages, but I don't know how "signing" packages works. So I was wondering how to create a signed deb package.
daniel hoggan
  • 173
11
votes
4 answers

Putting Digital Signature on PDF in Ubuntu 20.04

Adobe Acrobat DC on windows support this feature. While snap package adobe acrobat is partially functional on linux, as it logs incompatibility message. So actually I am looking for signing my offer letter pdf for joining I want to do it on ubuntu…
Sayan Dey
  • 278
10
votes
1 answer

What exactly is an ext4 signature and why am I removing it?

I was following the steps from an Ask Ubuntu answer (Increase partition size on which Ubuntu is installed?) to enlarge an Ubuntu VM I have and I'm wondering what is actually being removed here: Partition #1 contains a ext4 signature Do you want to…
Robert Houghton
  • 229
9
votes
3 answers

Yarn producing GPG Error

I am trying to update my Kubuntu 22.04 LTS. This error occurs: 7 packages can be upgraded. Run 'apt list --upgradable' to see them. W: An error occurred during the signature verification. The repository is not updated and the previous index files…
feration48
  • 423
  • 1
  • 4
  • 8
9
votes
2 answers

How to digitally sign documents in OpenOffice under Ubuntu?

On Ubuntu 19.04, Libreoffice seems to be there, but when I clicked, all the apps seem to be missing (like the word processor and the spreadsheet). So I first installed OpenOffice. Then I figured out that I could install Libreoffice as well: sudo apt…
Dov
  • 833
8
votes
4 answers

GPG Invalid Signature

I am having problems with the following (in an attempt to remove hyperlinks, I have removed one of the "/" from the addresses): W: GPG error: http://archive.ubuntu.com oneiric Release: The following signatures were invalid: BADSIG 40976EAF437D05B5…
Weiant2001
  • 89
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