no matching cipher found. Their offer: , fatal: Could not read from remote repository
Asked by Swapnil Hete:

Bamboo version: 5.9.4

OS : \[root@phoenix240862 .ssh\]# cat /etc/redhat-release  
Red Hat Enterprise Linux release 8.6 (Ootpa)

\[root@phoenix240862 .ssh\]# sshd -version  
unknown option -- v  
OpenSSH_8.0p1, OpenSSL 1.1.1k FIPS 25 Mar 2021

while cloning git repository in bamboo getting below error

```
com.atlassian.bamboo.repository.RepositoryException: java.lang.RuntimeException: com.atlassian.bamboo.repository.RepositoryException: com.atlassian.bamboo.plugins.git.GitCommandException: command /usr/bin/git ls-remote ssh://e452c039-1bf3-4468-8fb0-c7bdb8584722@127.0.0.1:35255/iotbca/infra/iot-infra.git failed with code 128. Working directory was [.]., stderr:[Unable to negotiate with 127.0.0.1 port 35255: no matching cipher found. Their offer: , fatal: Could not read from remote repository., , Please make sure you have the correct access rights, and the repository exists.]
```

![Screenshot 2023-03-15 at 2.30.27 PM.png](/t5/image/serverpage/image-id/245804i378E366308393BC1/image-size/large?v=v2&px=999 "Screenshot 2023-03-15 at 2.30.27 PM.png")


Answers:
author: Swapnil Hete
body: Thanks Nicolas and Edurado.

I was able to fix it as below.

As I was using very old version of bamboo 5.9.4 , I switched agent startup with lower version of java i.e JDK 1.8.0_91. This helped to fixed cipher issue.


author: Eduardo Alvarenga
body: Hello [@Swapnil Hete](/t5/user/viewprofilepage/user-id/5171239)

There is a mismatch between your SSH client-allowed ciphers and those the server allows you to use. This usually happens when the SSH server and client have a huge gap between their versions. From the reported OpenSSH version, I then assume your Bamboo release is older.

Try applying the workaround listed on this bug and let us know the results:

* <https://jira.atlassian.com/browse/BAM-21832>

Thank you,

Eduardo Alvarenga  
Atlassian Support APAC

**--please don't forget to Accept the answer if the reply is helpful--**

comments: author: Swapnil Hete
body: Hi [@Eduardo Alvarenga](/t5/user/viewprofilepage/user-id/4365410)   
I am following [BAM-21832](https://jira.atlassian.com/browse/BAM-21832) as you suggested.

What is file location \~./ssh_config?

Is it ?

1. /root/.ssh/config or 2./etc/ssh/ssh_config

Also, Yes looks like its openssh-server issue. I am trying OL7 VM as agent instead of OL8 as guided by [@Nicolas Grossi](/t5/user/viewprofilepage/user-id/676185) today in a call.

Thanks you for checking this issue.


author: Eduardo Alvarenga
body: Hello [@Swapnil Hete](/t5/user/viewprofilepage/user-id/5171239)

The SSH config can be either on:

* ***\<user_home\>/.ssh/config*** - On a per-user basis. *\<user_home\>* refers to the $HOME folder of the the user account that runs the Bamboo service
* ***/etc/ssh/config*** - On a global basis (all users will use that setting)

You need to add that setting on the Agent, meaning a Remote Agent or on the Bamboo Server if you are using a local agent.

Cheers,

Eduardo Alvarenga  
Atlassian Support APAC

**--please don't forget to Accept the answer if the reply is helpful--**


author: Swapnil Hete
body: I tried to set as /root/.ssh/config. Because my bamboo agent is running as root

But getting below error for new config

```
[root@mumbai246658 .ssh]# hostname
mumbai246658
[root@mumbai246658 .ssh]# pwd
/root/.ssh
[root@mumbai246658 .ssh]# cat /root/.ssh/config
Host 127.0.0.1
HostkeyAlgorithms +ssh-rsa
PubkeyAcceptedAlgorithms +ssh-rsa
[root@mumbai246658 .ssh]# sshd -V
unknown option -- V
OpenSSH_7.4p1, OpenSSL 1.0.2k-fips 26 Jan 2017
usage: sshd [-46DdeiqTt] [-C connection_spec] [-c host_cert_file]
[-E log_file] [-f config_file] [-g login_grace_time]
[-h host_key_file] [-o option] [-p port] [-u len]
[root@mumbai246658 .ssh]# /usr/bin/git ls-remote ssh://4f33fad2-850c-4f2c-bd95-daee1086499c@127.0.0.1:44697/iotbca/infra/iot-infra.git
/root/.ssh/config: line 3: Bad configuration option: pubkeyacceptedalgorithms
/root/.ssh/config: terminating, 1 bad configuration options
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
```


author: Eduardo Alvarenga
body: It is not necessary to add that property when using OpenSSH 7.4 as it already defaults to ssh-rsa.

Your Bamboo server also needs that property to reach the remote repository. Perhaps that's where you need to focus.

As you are running a really outdated version of Bamboo (5.9.4), you may have to play with other undocumented SSH settings to allow newer OpenSSH versions to interact with the old Apache-SSHD version that runs on Bamboo.

We recommend you plan an upgrade of Bamboo as soon as possible.

Eduardo Alvarenga  
Atlassian Support APAC

**--please don't forget to Accept the answer if the reply is helpful--**