title: AWS ssh access 'Permission denied (publickey)' issue
body: <p>How to connect to a AWS instance through ssh?</p>
  
  <p>I have:</p>
  
  <ol>
  <li>Signed up at AWS;</li>
  <li>Created a public key and a certificate at AWS website and saved them to disk;</li>
  <li><p>Went to my console and created environment variables:
  </p>
  
  <pre><code>$ export JAVA_HOME=/usr/lib/jvm/java-6-openjdk/
  $ export EC2_CERT=/home/default/aws/cert-EBAINCRNWHDSCWWIHSOKON2YWGJZ5LSQ.pem
  $ export EC2_PRIVATE_KEY=/home/default/aws/pk-EBAINCRNWHDSCWWIHSOKON2YWGJZ5LSQ.pem
  </code></pre></li>
  <li><p>Told AWS API to use this keypair and saved the keypair to file:
  </p>
  
  <pre><code>$ ec2-add-keypair ec2-keypair &gt; ec2-keypair.pem
  </code></pre></li>
  <li><p>Started an AWS Ubuntu 9 instance using this keypair:
  </p>
  
  <pre><code>$ ec2-run-instances ami-ed46a784 -k ec2-keypair
  </code></pre></li>
  <li><p>Attempted to establish a ssh connection to the instance:
  </p>
  
  <pre><code>$ ssh -v -i ec2-keypair.pem ubuntu@ec2-174-129-185-190.compute-1.amazonaws.com
  OpenSSH_5.1p1 Debian-5ubuntu1, OpenSSL 0.9.8g 19 Oct 2007
  debug1: Reading configuration data /etc/ssh/ssh_config
  debug1: Applying options for *
  debug1: Connecting to ec2-174-129-185-190.compute-1.amazonaws.com [174.129.185.190] port 22.
  debug1: Connection established.
  debug1: identity file ec2-keypair.pem type -1
  debug1: Remote protocol version 2.0, remote software version OpenSSH_5.1p1 Debian-5ubuntu1
  debug1: match: OpenSSH_5.1p1 Debian-5ubuntu1 pat OpenSSH*
  debug1: Enabling compatibility mode for protocol 2.0
  debug1: Local version string SSH-2.0-OpenSSH_5.1p1 Debian-5ubuntu1
  debug1: SSH2_MSG_KEXINIT sent
  debug1: SSH2_MSG_KEXINIT received
  debug1: kex: server-&gt;client aes128-cbc hmac-md5 none
  debug1: kex: client-&gt;server aes128-cbc hmac-md5 none
  debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024&lt;1024&lt;8192) sent
  debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
  debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
  debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
  debug1: Host 'ec2-174-129-185-190.compute-1.amazonaws.com' is known and matches the RSA host key.
  debug1: Found key in /home/default/.ssh/known_hosts:11
  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: ec2-keypair.pem
  debug1: read PEM private key done: type RSA
  debug1: Authentications that can continue: publickey
  debug1: No more authentication methods to try.
  Permission denied (publickey).
  </code></pre>
  
  <p>What could be the problem and how to make it work?</p></li>
  </ol>