GPGME error solved, but a question to understand the concept of pacman

kato · 2016-03-06 11:04:30

i tried pacman -Syu , then it shows me this error:

error: GPGME error: No data
error: GPGME error: No data
error: GPGME error: No data
:: Synchronizing package databases.
                      .
                      .
                      .
                      .

i was search about the problem then i found an answer in this link :
https://bbs.archlinux.org/viewtopic.php?id=142798

so my problrm was solved with this commands

pacman-key --init

and

pacman-key --populate archlinux

with database update in the end

pacman -Syy

after that i nedded to update so i ran

pacman -Su

it shows me

:: Proceed with installation? [Y/n] 
(44/44) checking keys in keyring                   [######################] 100%
(44/44) checking package integrity                 [######################] 100%
error: chromium: signature from "Evangelos Foutras <evangelos@foutrelis.com>" is invalid
:: File /var/cache/pacman/pkg/chromium-49.0.2623.75-1-x86_64.pkg.tar.xz is corrupted (invalid or corrupted package (PGP signature)).
Do you want to delete it? [Y/n] ^C
Interrupt signal received

and it was the same for every package in my computer , so i thought to delete one package then redownload and reinstalling it again:

[root@KAPAD Movie-Music----]# pacman -S ffmpeg
resolving dependencies...
looking for conflicting packages...

Packages (1) ffmpeg-1:3.0-1

Total Installed Size:  29.10 MiB
Net Upgrade Size:       4.41 MiB

:: Proceed with installation? [Y/n] 
(1/1) checking keys in keyring                     [######################] 100%
(1/1) checking package integrity                   [######################] 100%
error: ffmpeg: signature from "Maxime Gauduin <alucryd@archlinux.org>" is invalid
:: File /var/cache/pacman/pkg/ffmpeg-1:3.0-1-x86_64.pkg.tar.xz is corrupted (invalid or corrupted package (PGP signature)).
Do you want to delete it? [Y/n] y
error: failed to commit transaction (invalid or corrupted package (PGP signature))
Errors occurred, no packages were upgraded.

[root@KAPAD Movie-Music----]# pacman -S ffmpeg
resolving dependencies...
looking for conflicting packages...

Packages (1) ffmpeg-1:3.0-1

Total Download Size:    8.15 MiB
Total Installed Size:  29.10 MiB
Net Upgrade Size:       4.41 MiB

:: Proceed with installation? [Y/n] 
:: Retrieving packages ...
 ffmpeg-1:3.0-1-x86_64      8.2 MiB   122K/s 01:09 [######################] 100%
(1/1) checking keys in keyring                     [######################] 100%
(1/1) checking package integrity                   [######################] 100%
(1/1) loading package files                        [######################] 100%
(1/1) checking for file conflicts                  [######################] 100%
(1/1) checking available disk space                [######################] 100%
:: Processing package changes...
(1/1) upgrading ffmpeg                             [######################] 100%

it works now , but my question is how can i solve this problem without redownloading packags ,
and how can i change keys manually?[ i think its an stupid question which raise because of my cheap knowledge of encryption(if its true please suggest me some resource to understand it) ]
and i want to know how pacman works , is there any resource to study and understanding the concept?

WorMzy · 2016-03-06 12:21:45

Each signed package has a .sig file, generated by the packager, and containing a finger print of the package. If the .sig file or the package are altered in anyway (e.g. corrupted download, third party tampering, filesystem corruption), they no longer match, and the package cannot be trusted. To complicate things a bit more, signatures expire, so if your system time isn't right, you can get "signature is invalid" even though it's not. I suspect that's what has happened in your case.

See https://wiki.archlinux.org/index.php/Pa … ion_failed

TheChickenMan · 2016-03-06 15:07:34

WorMzy wrote:

To complicate things a bit more, signatures expire, so if your system time isn't right, you can get "signature is invalid" even though it's not. I suspect that's what has happened in your case.

I have a couple of old machines with dead motherboard batteries. Pacman gets unhappy any time their power fails and they lose the current time.
Make sure that the network time service is running so the clocks synchronize with the internet.

timedatectl set-ntp on

kato · 2016-03-06 20:54:25

but time in my computer is not wrong!
i guess its not about time because i installed ffmpeg package after removing it , reinstalling is the answer in here an i think the problem is about the signature of these packages , the question is how can i change signatures manually?(is that any way to do that?!!!) , i don't like to reinstall packages it means re-downloading package for me
, internet is not cheap here in Iran specially when your ISP is Mobinnet!

WorMzy wrote:

Each signed package has a .sig file, generated by the packager, and containing a finger print of the package. If the .sig file or the package are altered in anyway (e.g. corrupted download, third party tampering, filesystem corruption), they no longer match, and the package cannot be trusted. To complicate things a bit more, signatures expire, so if your system time isn't right, you can get "signature is invalid" even though it's not. I suspect that's what has happened in your case.
See https://wiki.archlinux.org/index.php/Pa … ion_failed

TheChickenMan wrote:

I have a couple of old machines with dead motherboard batteries. Pacman gets unhappy any time their power fails and they lose the current time.
Make sure that the network time service is running so the clocks synchronize with the internet.

timedatectl set-ntp on

TheChickenMan · 2016-03-06 23:12:13

Those errors are saying that the signatures on the updates packages which you just downloaded are invalid not that there is anything [necessarily] wrong with what is currently installed. If the time is correct you might want to try deleting Pacman's gpg cache and redownloading the keys.

rm -rf /etc/pacman.d/gnupg
pacman-key --init
pacman-key --populate archlinux

Arch Linux

#1 2016-03-06 11:04:30

GPGME error solved, but a question to understand the concept of pacman

#2 2016-03-06 12:21:45

Re: GPGME error solved, but a question to understand the concept of pacman

#3 2016-03-06 15:07:34

Re: GPGME error solved, but a question to understand the concept of pacman

#4 2016-03-06 20:54:25

Re: GPGME error solved, but a question to understand the concept of pacman

#5 2016-03-06 23:12:13

Re: GPGME error solved, but a question to understand the concept of pacman

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