Questions tagged [signature]

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4 answers
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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 ...
user avatar
19 votes
4 answers
33k views

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 ...
Geoffrey's user avatar
  • 445
58 votes
13 answers
138k views

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 ...
Agmenor's user avatar
  • 16.2k
24 votes
2 answers
7k views

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] ...
Broadsworde's user avatar
  • 4,132
17 votes
2 answers
8k views

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 ...
Byte Commander's user avatar
  • 107k
8 votes
4 answers
40k views

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 ...
Weiant2001's user avatar
3 votes
2 answers
2k views

What is wrong with ddebs.ubuntu.com

Did something expire that should not have? I am using debug symbols on my Ubuntu 20.10 install, and now I get this when I run the apt-get update command. W: An error occurred during the signature ...
Bram's user avatar
  • 2,469
2 votes
1 answer
3k views

Ubuntu 18.04 - after upgrade - Display/PKCS#7 signature error

After upgrading from 17.10 to 18.04, anytime I try and open Ubuntu I am getting the following errors (which are found in my kern.log as well) Sep 28 15:06:12 aram-UX330UAK kernel: [ 15.056052] PKCS#...
Aram Papazian's user avatar
2 votes
1 answer
4k views

Ubuntu Extras keyring error [duplicate]

Recently I got lots of GPG errors and tried the following methods at various stages: sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 3E5C1192 sudo apt-get install -reinstall ubuntu-...
Pawan Neupane's user avatar
25 votes
1 answer
16k views

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 ...
jorgehsrama's user avatar
16 votes
2 answers
17k views

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's user avatar
7 votes
4 answers
4k views

Why does Empathy say my connection is untrusted?

Today when I opened Empathy on Ubuntu 10.10 I got this unusual error box. I have never got this warning about an untrusted connection before. What should I do? Is it a security risk if I continue ...
Gaurav Butola's user avatar
6 votes
1 answer
2k views

How does Secure Boot actually work?

I'm playing with GRUB2, SecureBoot and Kernel Signing and I think I found a possible bug in my Secure Boot, but I want to check my understanding of these processes first. I know that when Secure Boot ...
JumpAlways's user avatar
3 votes
2 answers
13k views

How to handle "invalid signature" in apt-get

Following an update to Focal, I had to revisit /etc/apt/sources* to update my third party repositories. One of the reposities is for the Yorba PPA at: https://launchpad.net/~yorba/+archive/ubuntu/ppa ...
user1283068's user avatar
3 votes
2 answers
6k views

What exactly does a BAD signature mean?

About 16 hours ago I downloaded the Ubuntu 18.04.5 image from releases.ubuntu.com alongside its checksum file and GnuPG signature. Verifying the checksum file using the signature results in a BAD ...
Akbarkhon Variskhanov's user avatar
3 votes
1 answer
1k views

LibreOffice fails to access my personal certificate

Recently, I updated my personal certificate. Then I wanted to sign a libreoffice document. I followed the instructions from Part 1 to Part 4. Both Thunderbird and Firefox are displaying the correct, ...
Danka Banka's user avatar
2 votes
1 answer
409 views

How to publish your key used to sign deb packages so you will be able to use your repository from any machine?

I am looking for a solution that would prevent me from seeing things like: W: GPG error: http://updates.example.com lenny Release: The following signatures couldn't be verified because the public key ...
sorin's user avatar
  • 9,868
2 votes
1 answer
2k views

How to check if PDF document has been signed (probably with Adobe)?

I'm on Xubuntu 18.04.4 LTS. I received a document, then forwarded it to other people who should be able to modify it. However digital signatures might prevent that. How do I check if Adobe was used to ...
PlasmaBinturong's user avatar
1 vote
1 answer
397 views

Digital signing with qdigidoc4 (Estonian ID card software) under Ubuntu 20.04

When trying to use qdigidoc4 (version 4.2.4.71) on Ubuntu 20.04, and trying to sign a container, signing fails (both with ID card and Mobile ID) and I get the following message: ASiC_E.cpp:347 Failed ...
dominique-u's user avatar
1 vote
1 answer
6k views

Generating, Signing and Verifying Digital Certificates

So here's a question from my project. In this task, we will use OpenSSL to generate digital signatures. Please prepare a file (example.txt) of any size. Also prepare an RSA public/private key pair. ...
Data Shark's user avatar