[git] Github의 ssh key 이슈

git 에서 특이한 현상이 있다.

github A 프로젝트를 clone 후,  파일 수정/add/commit/push 한다. 그리고 push를 시도한다.

그러나, github B 프로젝트로 push하는 황당한(?)일이 벌어진다.

ERROR: Permission to ProjectA denied to ProjectB

fatal: The remote end hung up unexpectedly

SSH 디버그로 설정해도 특이한 현상이다. 

$ git clone git@github.xxxx.com:projectA.git
Initialized empty Git repository in ....
remote: Counting objects: 3194, done.
remote: Total 3194 (delta 0), reused 0 (delta 0), pack-reused 3194
Receiving objects: 100% (3194/3194), 9.45 MiB, done.
Resolving deltas: 100% (1415/1415), done.
$ cd projectA
$ vi test
$ git status
# On branch master
# Changed but not updated:
#   (use "git add <file>..." to update what will be committed)
#   (use "git checkout -- <file>..." to discard changes in working directory)
#
#	modified:   test
#
no changes added to commit (use "git add" and/or "git commit -a")
$ git add .
$ git commit -m '11'
[master 6d243f2] 11
 1 files changed, 1 insertions(+), 0 deletions(-)
$ git push
debug1: Connecting to github.xxxx.com [1.1.1.1] port 22.
debug1: Connection established.
debug1: identity file /home/www/.ssh/identity type -1
debug1: identity file /home/www/.ssh/identity-cert type -1
debug1: identity file /home/www/.ssh/id_rsa type -1
debug1: identity file /home/www/.ssh/id_rsa-cert type -1
debug1: identity file /home/www/.ssh/id_dsa type -1
debug1: identity file /home/www/.ssh/id_dsa-cert type -1
debug1: Remote protocol version 2.0, remote software version libssh-0.6.0
debug1: no match: libssh-0.6.0
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.3
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-sha1 none
debug1: kex: client->server aes128-ctr hmac-sha1 none
debug1: sending SSH2_MSG_KEXDH_INIT
debug1: expecting SSH2_MSG_KEXDH_REPLY
debug1: Host 'github.xxx.com' is known and matches the RSA host key.
debug1: Found key in /home/www/.ssh/known_hosts:8
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /home/www/.ssh/identity
debug1: Trying private key: /home/www/.ssh/id_rsa
debug1: read PEM private key done: type RSA
debug1: Authentication succeeded (publickey).
debug1: channel 0: new [client-session]
debug1: Entering interactive session.
debug1: Sending environment.
debug1: Sending env LANG = ko_KR.UTF-8
debug1: Sending command: git-receive-pack 'projectA.git'
debug1: client_input_channel_req: channel 0 rtype exit-status reply 0
ERROR: Permission to ProjectA denied to ProjectB.
debug1: channel 0: free: client-session, nchannels 1
debug1: fd 0 clearing O_NONBLOCK
debug1: fd 1 clearing O_NONBLOCK
Transferred: sent 2208, received 1680 bytes, in 0.1 seconds
Bytes per second: sent 38768.0, received 29497.4
debug1: Exit status 1
fatal: The remote end hung up unexpectedly

git config --list 또는 cat .git/config 에서도 projectA.git로 제대로 나온다!!!

문제 해결은 ssh key를 삭제하고 다시 ssh gen을 하고 ssh key를 다시 등록하니 정상적으로 작동했다. 만약 주의 깊게 보지 않고 -f(force push)매개변수를 주었다면 민폐가 되었을 것이다.

아마도 '잘못된 SSH 키가 꼬이면, git push할 때 다른 프로젝트로 결합되어 엉뚱한 작업을 진행할 수 있다'라고 가정할 수 있는 환경을 공유한다.

따라서 git push -f는 정말 신중하게 써야 한다.!! 잘못하면 엉뚱한 github 프로젝트를 엉뚱하게 변경할 가능성이 존재한다.

참고

https://help.github.com/enterprise/2.4/user/articles/error-permission-to-user-repo-denied-to-user-other-repo/