多个 Github 账号配置 SSH Key 的问题

[Yiskiee]

问题描述

• 当创建两个不同的 ssh key 来设置两个 Github 账号时, 我发现它们不能同时通过 Github 的认证, 只有一个可以与 Github 连接, 并克隆仓库. 我查找了网上不少有关配置多个账号和多个 SSH Key 的资料, 依然没有解决这个问题.

• 以前用 Ubuntu20.4 时配置成功过, 改用 Fedora36 后就一直没解决这个问题, 故来请教一下大家.

运行环境

• OS: Fedora Linux 36 (Workstation Edition) x86_64
• Kernel: 5.19.14-200.fc36.x86_64
• OpenSSH: OpenSSH_8.8p1, OpenSSL 3.0.5 5 Jul 2022
• Git: git version 2.37.3

问题复现

• 删除 $HOME/.ssh/ 文件夹, 清除代理

$ rm -r $HOME/.ssh/
$ ssh-add -D && ssh-add -l

• 新建两个 SSH Key, (以 com 和 net 为例):

$ ssh-keygen -t rsa -C "[e-mail]" -f $HOME/.ssh/id_rsa_com
$ ssh-keygen -t rsa -C "[e-mail]" -f $HOME/.ssh/id_rsa_net

• 编辑 $HOME/.ssh/config 添加以下内容:

Host com
    HostName        github.com
    User            git
    IdentityFile    $HOME/.ssh/id_rsa_com
    ProxyCommand    ncat --proxy 127.0.0.1:1089 --proxy-type socks5 %h %p

Host net
    HostName        github.com
    User            git
    IdentityFile    $HOME/.ssh/id_rsa_net
    ProxyCommand    ncat --proxy 127.0.0.1:1089 --proxy-type socks5 %h %p

• 添加公钥到对应的 Github 账户

• 测试服务器连通性:

  • 运行 ssh -T git@com 回车后询问是否继续, 输入 yes 后继续, 提示 com 的账号成功通过身份验证.
  • 运行 ssh -T git@net 回车后, 提示 com 的账号成功通过身份验证.

• 使用 Git 克隆不同账号的私有仓库:

  • 运行 git clone git@com:com_example/example.git 回车后, 克隆成功.
  • 运行 git clone git@net:net_example/example.git 回车后, 克隆失败, 提示如下:

ERROR: Repository not found.
fatal: Could not read from remote repository.

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

[ob]

没看到你把 key 重新添加啊？
ssh-add -k id_rsa_com
ssh-add -k id_rsa_net

[ob]

net 不行，先添加 net ，然后再试下

[corvofeng]

你先把 com 的删掉, 看看能不能登录 net, 我怀疑你拷贝公钥的时候拷贝错了..

[charlie21]

用如下命令查看连接细节
ssh -Tv git@com
ssh -Tv git@net

为 Host 增加 IdentitiesOnly 如下，另一块同理
Host com
HostName github.com
User git
IdentityFile $HOME/.ssh/id_rsa_com
IdentitiesOnly yes
ProxyCommand ncat --proxy 127.0.0.1:1089 --proxy-type socks5 %h %p

参考
https://superuser.com/questions/268776/how-do-i-configure-ssh-so-it-doesnt-try-all-the-identity-files-automatically

[Yiskiee]

@ob
@corvofeng
@charlie21
为验证这些问题, 我将 id_rsa_com 和 id_rsa_net 分别移动到其他文件夹下.
将 config 文件中的所有内容注释, 删除 known_hosts 和 known_hosts.old
执行 ssh-add -D && ssh-add -l 确认没有内容后:
先移动 net 的 Key 后执行 ssh-add -k $HOME/.ssh/id_rsa_net
后移动 com 的 Key 后执行 ssh-add -k $HOME/.ssh/id_rsa_com
编辑 config 将 Host net 的内容移动到 Host com 之前, 其他只字未改.

执行 ssh -Tv git@net, 结果如下:
```
OpenSSH_8.8p1, OpenSSL 3.0.5 5 Jul 2022
debug1: Reading configuration data /home/umze/.ssh/config
debug1: /home/umze/.ssh/config line 2: Applying options for net
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Reading configuration data /etc/ssh/ssh_config.d/50-redhat.conf
debug1: Reading configuration data /etc/crypto-policies/back-ends/openssh.config
debug1: configuration requests final Match pass
debug1: re-parsing configuration
debug1: Reading configuration data /home/umze/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Reading configuration data /etc/ssh/ssh_config.d/50-redhat.conf
debug1: Reading configuration data /etc/crypto-policies/back-ends/openssh.config
debug1: Executing proxy command: exec ncat --proxy 127.0.0.1:1089 --proxy-type socks5 github.com 22
debug1: identity file $HOME/.ssh/id_rsa_net type -1
debug1: identity file $HOME/.ssh/id_rsa_net-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.8
debug1: Remote protocol version 2.0, remote software version babeld-f33ee42f
debug1: compat_banner: no match: babeld-f33ee42f
debug1: Authenticating to github.com:22 as 'git'
debug1: load_hostkeys: fopen /home/umze/.ssh/known_hosts: No such file or directory
debug1: load_hostkeys: fopen /home/umze/.ssh/known_hosts2: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts2: No such file or directory
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: curve25519-sha256
debug1: kex: host key algorithm: ssh-ed25519
debug1: kex: server->client cipher: [e-mail] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [e-mail] MAC: <implicit> compression: none
debug1: kex: curve25519-sha256 need=32 dh_need=32
debug1: kex: curve25519-sha256 need=32 dh_need=32
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: SSH2_MSG_KEX_ECDH_REPLY received
debug1: Server host key: ssh-ed25519 SHA256:+DiY3wvvV6TuJJhbpZisF/zLDA0zPMSvHdkr4UvCOqU
debug1: load_hostkeys: fopen /home/umze/.ssh/known_hosts: No such file or directory
debug1: load_hostkeys: fopen /home/umze/.ssh/known_hosts2: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts2: No such file or directory
debug1: hostkeys_find_by_key_hostfile: hostkeys file /home/umze/.ssh/known_hosts does not exist
debug1: hostkeys_find_by_key_hostfile: hostkeys file /home/umze/.ssh/known_hosts2 does not exist
debug1: hostkeys_find_by_key_hostfile: hostkeys file /etc/ssh/ssh_known_hosts does not exist
debug1: hostkeys_find_by_key_hostfile: hostkeys file /etc/ssh/ssh_known_hosts2 does not exist
The authenticity of host 'github.com (<no hostip for proxy command>)' can't be established.
ED25519 key fingerprint is SHA256:+DiY3wvvV6TuJJhbpZisF/zLDA0zPMSvHdkr4UvCOqU.
This key is not known by any other names
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added 'github.com' (ED25519) to the list of known hosts.
debug1: rekey out after 4294967296 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: rekey in after 4294967296 blocks
debug1: Will attempt key: [e-mail] RSA SHA256:eQ5AqN8Y+p9cGo8eVzcxOMmJgDN3ivpCbcgA7jkkXeI agent
debug1: Will attempt key: [e-mail] RSA SHA256:H790emQkwtjDRSnGyRxp0e+HnlxlAY5ruEFLrxw6VtQ agent
debug1: Will attempt key: $HOME/.ssh/id_rsa_net explicit
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],ssh-ed25519,ecdsa-sha2-nistp521,ecdsa-sha2-nistp384,ecdsa-sha2-nistp256,rsa-sha2-512,rsa-sha2-256,ssh-rsa>
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering public key: [e-mail] RSA SHA256:eQ5AqN8Y+p9cGo8eVzcxOMmJgDN3ivpCbcgA7jkkXeI agent
debug1: Server accepts key: [e-mail] RSA SHA256:eQ5AqN8Y+p9cGo8eVzcxOMmJgDN3ivpCbcgA7jkkXeI agent
Authenticated to github.com (via proxy) using "publickey".
debug1: pkcs11_del_provider: called, provider_id = (null)
debug1: channel 0: new [client-session]
debug1: Entering interactive session.
debug1: pledge: filesystem full
debug1: client_input_global_request: rtype [e-mail] want_reply 0
debug1: client_input_hostkeys: searching /home/umze/.ssh/known_hosts for github.com / (none)
debug1: client_input_hostkeys: searching /home/umze/.ssh/known_hosts2 for github.com / (none)
debug1: client_input_hostkeys: hostkeys file /home/umze/.ssh/known_hosts2 does not exist
debug1: Sending environment.
debug1: channel 0: setting env XMODIFIERS = "@im=ibus"
debug1: channel 0: setting env LANG = "en_US.UTF-8"
Learned new hostkey: RSA SHA256:nThbg6kXUpJWGl7E1IGOCspRomTxdCARLviKw6E5SY8
Learned new hostkey: ECDSA SHA256:p2QAMXNIC1TJYWeIOttrVc98/R1BUFWu3/LiyKgUfQM
Adding new key for github.com to /home/umze/.ssh/known_hosts: ssh-rsa SHA256:nThbg6kXUpJWGl7E1IGOCspRomTxdCARLviKw6E5SY8
Adding new key for github.com to /home/umze/.ssh/known_hosts: ecdsa-sha2-nistp256 SHA256:p2QAMXNIC1TJYWeIOttrVc98/R1BUFWu3/LiyKgUfQM
debug1: update_known_hosts: known hosts file /home/umze/.ssh/known_hosts2 does not exist
debug1: client_input_channel_req: channel 0 rtype exit-status reply 0
Hi net! You've successfully authenticated, but GitHub does not provide shell access.
debug1: channel 0: free: client-session, nchannels 1
Transferred: sent 3564, received 3176 bytes, in 0.7 seconds
Bytes per second: sent 5290.0, received 4714.1
debug1: Exit status 1
```
字数限制, 另起一个回复

[Yiskiee]

@ob
@corvofeng
@charlie21
接上文:
执行 ssh -Tv git@com, 结果如下 (回复受限, 去除了大部分内容):
```
Hi net! You've successfully authenticated, but GitHub does not provide shell access.
debug1: channel 0: free: client-session, nchannels 1
Transferred: sent 3128, received 2752 bytes, in 0.7 seconds
Bytes per second: sent 4500.6, received 3959.6
debug1: Exit status 1
```

为各 Host 增加 IdentitiesOnly

执行 ssh -T git@net:
```
no such identity: $HOME/.ssh/id_rsa_net: No such file or directory
[e-mail]: Permission denied (publickey).
```


执行 ssh -T git@com:
```
no such identity: $HOME/.ssh/id_rsa_com: No such file or directory
[e-mail]: Permission denied (publickey).
```

[ob]

@Yiskiee 同在 linux 环境下验证过，可能有点不一样，试着加下这两个配置：(mac 的，不知道是不是通用)
AddKeysToAgent yes
UseKeychain yes

[Yiskiee]

@ob 试了一下, 第一条配置存在, 但没有解决这个问题, 第二条配置不可用.

[ob]

@Yiskiee 把 config 文件里面的$HOME 改成~
我试着用最基本的配置，其他什么都不加都不配，也能成功 clone 不同账号 repo

Host com
HostName github.com
IdentityFile ~/.ssh/id_rsa_com
User git

Host net
HostName github.com
IdentityFile ~/.ssh/id_rsa_net
User git

[Yiskiee]

@ob 十分感谢! ssh -T 测试成功了, git 克隆私有库也成功了, 实在是不理解为什么会有这种问题.