Questions tagged [signature]

111 questions
55
votes
13 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
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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
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50
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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
25
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
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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
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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
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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
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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
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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
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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
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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
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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
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GPG says that it needs a passphrase but it actually doesn't

I try to use GPG to sign files but something confuses me: If I enter in the terminal (the file I want to sign is called "checksums") it says: $ gpg -s checksums You need a passphrase to unlock the secret key for user: "[my name] <[my email…
UTF-8
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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 without a second guess?
Gaurav Butola
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