Multiple SSH keys for different accounts

Problem is, Bitbucket doesn’t allow you to use the same SSH key with more than one Bitbucket account.

As GitHub explains you can generate an SSH key like so:

cd ~/.ssh
ssh-keygen -t rsa -C "your_email@youremail.com"

You are then prompted for an optional password. After the key is generate you copy & paste it into your GitHub or Bitbucket account settings. On Mac OS X (10.8), which I’m using, copying to the clipboard is simple:

pbcopy < ~/.ssh/id_rsa.pub

With multiple Bitbucket accounts (and I assume GitHub too) you need multiple SSH keys. To generate a second key with a different name:

ssh-keygen -t rsa -f ~/.ssh/accountB -C "your_email@youremail.com"

To use multiple keys create a file at ~/.ssh/config with contents similar to:

Host bitbucket.org
  User git
  Hostname bitbucket.org
  PreferredAuthentications publickey
  IdentityFile ~/.ssh/id_rsa

Host bitbucket-accountB
  User git
  Hostname bitbucket.org
  PreferredAuthentications publickey
  IdentitiesOnly yes
  IdentityFile ~/.ssh/accountB

With this set up I can clone with my default key as Bitbucket suggests:

git clone git@bitbucket.org:username/project.git

If I want to clone a repository from my second account I can alter the command to use the second SSH key I generated:

git clone git@bitbucket-accountB:username/project.git

In fact, if I wanted to I could have a different SSH key for every account I have; GitHub, Bitbucket, or any other service that requires one.