Why does SSH refuse my RSA publickey?

After successfully generating RSA keys and copying the public key to the remote authorized_hosts, I have encountered many times a message like this when trying to ssh in:

Executing: program /usr/bin/ssh host
office-minimac, user (unspecified), command scp -v -t
~/.ssh/authorized_keys
OpenSSH_5.1p1, OpenSSL 0.9.8g 19 Oct 2007
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to office-minimac [192.168.2.103] port 22.
debug1: Connection established.
debug1: identity file /home/drsavoye/.ssh/identity type -1
debug1: identity file /home/drsavoye/.ssh/id_rsa type 1
debug1: identity file /home/drsavoye/.ssh/id_dsa type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_4.3
debug1: match: OpenSSH_4.3 pat OpenSSH_4*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.1
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-cbc hmac-md5 none
debug1: kex: client->server aes128-cbc hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<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 'office-minimac' is known and matches the RSA host key.
debug1: Found key in /home/drsavoye/.ssh/known_hosts:1
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,gssapi-with-mic,password
debug1: Next authentication method: gssapi-with-mic
debug1: Unspecified GSS failure. Minor code may provide more
information
No credentials cache found

debug1: Unspecified GSS failure. Minor code may provide more
information
No credentials cache found

debug1: Unspecified GSS failure. Minor code may provide more
information


debug1: Next authentication method: publickey
debug1: Trying private key: /home/drsavoye/.ssh/identity
debug1: Offering public key: /home/drsavoye/.ssh/id_rsa
debug1: Authentications that can continue:
publickey,gssapi-with-mic,password
debug1: Trying private key: /home/drsavoye/.ssh/id_dsa
debug1: Next authentication method: password
drsavoye@office-minimac's password:

This happens when the permissions of the .ssh directory or any of its items are incorrect. Commonly the mode of the .ssh directory itself will be set to 775 or 777; setting group write permissions on any of the files will cause this effect. The correct permissions of the .ssh directory:

~/.ssh{drsavoye@ushuaia} pts/4$ ls -la
total 40
drwxr-xr-x    2    drsavoye drsavoye  4096  feb 26 08:31 .
drwxr-xr-x    143  drsavoye drsavoye 20480  feb 26 08:31 ..
-rw-r--r--    1    drsavoye drsavoye   408  feb 25 22:01 authorized_keys
-rw-------    1    drsavoye drsavoye  1671  feb 25 22:01 id_rsa
-rw-r--r--    1    drsavoye drsavoye   405  feb 25 22:01 id_rsa.pub
-rw-r--r--    1    drsavoye drsavoye   810  feb 25 22:01 known_hosts

If they differ, use chmod 755 ~/.ssh and chmod 644 ~/.ssh/* to correct them.

Tip: using ssh -vvv {host} will return this verbose output.