Cannot push to Heroku because key fingerprint

Question

I had the same problem, I followed this post and others of the same kind without success :-((

Finally, I found the solution: I had to add my new rsa identity in my machine!

So, first of all I created a new rsa key:

ssh-keygen -t rsa -C "giordano.scalzo[at]gmail.com" -f  ~/.ssh/id_rsa_heroku

then added it to my machine

ssh-add ~/.ssh/id_rsa_heroku

and, finally, to Heroku

heroku keys:add ~/.ssh/id_rsa_heroku.pub

After that,

git push heroku master

worked like a charm!

Hope this helps.

I, too have multiple keys and multiple heroku accounts, so I come across this problem every few months. As mentioned Giordano Scalzo, Tom Carchrae, and user664833, the main problem is ssh-agent, which you control using the ssh-add command. The man page (man ssh-add) is actually pretty clear and concise, so check it out.

You can list all the keys that ssh-agent knows about with:

ssh-add -l

You can delete all the keys that ssh-agent knows about with:

ssh-add -D

Or delete a specific key with

ssh-add -d ~/.ssh/id_rsa_example_key_file_use_your_own

Don't worry! You aren't actually deleting the keys, only changing which ones ssh-agent automatically tries to use, for example, when you try to push to heroku. It's easy to add and delete keys as needed, so for me, when I get frustrated by this problem, the easiest way to fix it is to delete all the keys and add back in only the one I want to use at the moment.

ssh-add -D
ssh-add ~/.ssh/id_rsa_example_use_this_one_i_mean_it

Your computer has an SSH key, but that SSH key is associated with another Heroku account.

If you need to use both accounts for different applications on the same computer you should make a new SSH key on your machine and upload it to Heroku:

$ ssh-keygen

Make sure to save it as '/Users/User/.ssh/new_id_rsa.pub' when the prompt asks you.

$ heroku keys:add /Users/User/.ssh/new_id_rsa.pub 

You then need to add an alternate host for heroku.com to your ~/.ssh/config:

Host heroku-alt
HostName heroku.com
IdentityFile ~/.ssh/new_id_rsa

And then update the .git/config in your project to use the host alias:

[remote "heroku"]
  url = git@heroku-alt:myapp.git
  fetch = +refs/heads/*:refs/remotes/heroku/*

By choosing between heroku and heroku-alt in the remote of the .git/config files of specific projects you can manage which projects use which credentials.

Here's a very clear explanation that is lacking from ther Heroku documentation or other answers to the question. At least all the info doesn't seem to appear in any one place. It also let's you understand the problem in a way that the accounts tool doesn't.

Heroku identifies you in 2 ways:

The first is in .git/config

[heroku]
    account = acccount_name

This seems to let you perform basic operations using heroku

The second way heroku identifies you is by any operation that uses ssh (git push). Heroku will identify you by your ssh key, as stated here: https://devcenter.heroku.com/articles/keys

This keypair is used for the strong cryptography and that uniquely identifies you as a developer when pushing code changes.

So each heroku account that you work on will have to send a different key to heroku when using ssh. Follow any tutorial to create your ssh keys.

The key is getting SSH to use different keys for each Heroku account. How do you do configure this? You'll need to do 2 things:

1) You'll need to make a 'dummy' domain that your .ssh/config will intercept and reconfigure. This will tell ssh the 'actual' domain you want, and which special ssh key to use.

Host heroku.my_unique_key
  HostName heroku.com
  IdentityFile ~/.ssh/identity.heroku.my_unique_key
  IdentitiesOnly yes

2) Change your .git/config to use that when using git push. Instead of heroku.com, use the dummy domain you set in your .ssh/config

[remote "heroku"]
    url = [email protected]


[remote "heroku"]
    url = [email protected]_unique_key:myapp.git

That's it :) A bit complicated and a bit simple at the same time. It has taken me 3 years of banging my head against the wall and trial and error to discover this info. It should be clearly documented somewhere, but at least it's a start.

youn will need to create new keys and add those

specify a new file name after running

ssh-keygen

then (in my case)

heroku keys:add /home/alex/.ssh/alex_heroku_rsa.pub

I have the same issue last week. This linked helped me out. I hope it helps you out a little. http://devcenter.heroku.com/articles/keys