这是我的问题。
我创建了一个新实例，使用另一个实例的相同密钥对。
SSH 到新实例，运行正常。
我终止了旧实例。
当我使用密钥 SSH 到我的新实例时，它就出现了问题。
OpenSSH_5.6p1, OpenSSL 0.9.8r 8 Feb 2011
debug1: Reading configuration data /etc/ssh_config
debug1: Applying options for *
debug1: Connecting to ec2-176-34-8-64.ap-northeast-1.compute.amazonaws.com [176.34.8.64] port 22.
debug1: Connection established.
debug1: identity file foobar.pem type -1
debug1: identity file foobar.pem-cert type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3
debug1: match: OpenSSH_5.3 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.6
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5 none
debug1: kex: client->server aes128-ctr 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 'ec2-176-34-8-64.ap-northeast-1.compute.amazonaws.com' is known and matches the RSA host key.
debug1: Found key in /Users/xudannie/.ssh/known_hosts:12
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /Users/xudannie/.ssh/id_rsa
debug1: Authentications that can continue: publickey
debug1: Trying private key: foobar.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).
所以我检查了其他答案，也许我应该创建一个新实例并挂载这个实例以添加公钥。这是解决问题的唯一方法吗？
感谢帮助。