# Mcr.microsoft.com/dotnet/aspnet:6.0-jammy \`signatures couldn't be verified because the public key is not available\`

**URL:** <https://discuss.circleci.com/t/mcr-microsoft-com-dotnet-aspnet-6-0-jammy-signatures-couldnt-be-verified-because-the-public-key-is-not-available/43851>\
**Category:** Build Environment\
**Tags:** ubuntu-2204, dotnet, docker, .net\
**Created:** [April 28, 2022, 8:33am UTC](https://discuss.circleci.com/t/mcr-microsoft-com-dotnet-aspnet-6-0-jammy-signatures-couldnt-be-verified-because-the-public-key-is-not-available/43851 "2022-04-28T08:33:41Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![khteh](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/khteh/32/21059_2.png) [@khteh](https://discuss.circleci.com/u/khteh)\
**Post date:** [April 28, 2022, 8:33am UTC](https://discuss.circleci.com/t/mcr-microsoft-com-dotnet-aspnet-6-0-jammy-signatures-couldnt-be-verified-because-the-public-key-is-not-available/43851/1 "2022-04-28T08:33:41Z")

</div>

Building [ASP.Net](http://ASP.Net) 6 docker image using `mcr.microsoft.com/dotnet/aspnet:6.0-jammy` bumps into

```auto
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY

```

Any advice and insight is appreciated.

---

<div class="post-metadata">

**Author:** ![jerdog](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/jerdog/32/32130_2.png) [@jerdog](https://discuss.circleci.com/u/jerdog)\
**Post date:** [May 3, 2022, 5:17pm UTC](https://discuss.circleci.com/t/mcr-microsoft-com-dotnet-aspnet-6-0-jammy-signatures-couldnt-be-verified-because-the-public-key-is-not-available/43851/2 "2022-05-03T17:17:43Z")

</div>

Would you be able to post your config so we can review what parameters are in place? Also, depending on where it is in the config process, it could be related to the changes GitHub made on which SSH keys are able to access

> **[Improving Git protocol security on GitHub | The GitHub Blog](https://github.blog/2021-09-01-improving-git-protocol-security-github/)**
>
> We’re changing which keys are supported in SSH and removing unencrypted Git protocol. If you’re an SSH user, read on for the details and timeline.

---

<div class="post-metadata">

**Author:** ![khteh](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/khteh/32/21059_2.png) [@khteh](https://discuss.circleci.com/u/khteh)\
**Post date:** [May 3, 2022, 11:37pm UTC](https://discuss.circleci.com/t/mcr-microsoft-com-dotnet-aspnet-6-0-jammy-signatures-couldnt-be-verified-because-the-public-key-is-not-available/43851/3 "2022-05-03T23:37:19Z")

</div>

This is the config in the repo: [AspNetCoreApiStarter/config.yml at master · khteh/AspNetCoreApiStarter · GitHub](https://github.com/khteh/AspNetCoreApiStarter/blob/master/.circleci/config.yml)

This is the docker build failure: [https://app.circleci.com/pipelines/github/khteh/AspNetCoreApiStarter/278/workflows/8ba4d75a-e8c6-499d-907e-ac545105f638/jobs/289/parallel-runs/0/steps/0-111](https://app.circleci.com/pipelines/github/khteh/AspNetCoreApiStarter/278/workflows/8ba4d75a-e8c6-499d-907e-ac545105f638/jobs/289/parallel-runs/0/steps/0-111)

---

<div class="post-metadata">

**Author:** ![khteh](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/khteh/32/21059_2.png) [@khteh](https://discuss.circleci.com/u/khteh)\
**Post date:** [May 13, 2022, 8:14am UTC](https://discuss.circleci.com/t/mcr-microsoft-com-dotnet-aspnet-6-0-jammy-signatures-couldnt-be-verified-because-the-public-key-is-not-available/43851/4 "2022-05-13T08:14:13Z")

</div>

Any update on this?

---

<div class="post-metadata">

**Author:** ![Star](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/star/32/30116_2.png) [@Star](https://discuss.circleci.com/u/Star)\
**Post date:** [May 16, 2022, 12:00am UTC](https://discuss.circleci.com/t/mcr-microsoft-com-dotnet-aspnet-6-0-jammy-signatures-couldnt-be-verified-because-the-public-key-is-not-available/43851/5 "2022-05-16T00:00:06Z")

</div>

man u came to the wrong place, stack overlow i think would be better, no one checks this Forum, i dont even know why they have it up

---

<div class="post-metadata">

**Author:** ![jbuck](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/jbuck/32/30170_2.png) [@jbuck](https://discuss.circleci.com/u/jbuck)\
**Post date:** [May 16, 2022, 6:55pm UTC](https://discuss.circleci.com/t/mcr-microsoft-com-dotnet-aspnet-6-0-jammy-signatures-couldnt-be-verified-because-the-public-key-is-not-available/43851/6 "2022-05-16T18:55:08Z")

</div>

Hi there, I was running into the same problem, and upgrading the docker engine version in the setup\_remote\_docker fixed the issue for me. So you’d change your YAML to something like:

```auto
- setup_remote_docker:
    version: 20.10.14

```

As for _why_ this fixes the problem, the Circle CI remote docker version is `17.09.0-ce` and I found this blog saying that a change in glibc that’s incompatible with Docker \<= 20.10.8 is the cause of this issue: [docker运行ubuntu22.04出现异常 | DevopsApple](https://xyz-uscwifi-xyz.translate.goog/post/PRTc2ZYZx/?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp) . Hope this helps you too!

---

<div class="post-metadata">

**Author:** ![jbuck](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/jbuck/32/30170_2.png) [@jbuck](https://discuss.circleci.com/u/jbuck)\
**Post date:** [May 16, 2022, 7:03pm UTC](https://discuss.circleci.com/t/mcr-microsoft-com-dotnet-aspnet-6-0-jammy-signatures-couldnt-be-verified-because-the-public-key-is-not-available/43851/7 "2022-05-16T19:03:31Z")

</div>

Ah, I see this also mentioned in [Ubuntu 22.04 Jammy Jellyfish Now Available for Beta Testing - #5 by Masahiko](https://discuss.circleci.com/t/ubuntu-22-04-jammy-jellyfish-now-available-for-beta-testing/43440/5) - This should probably be easier to find…