我已基于 php cloudformatino 映像 ami-6fc2f61b 创建了一个新的 ec2 实例，并将我现有的密钥附加到该实例。安全组允许 ssh 和 http。但是，我无法连接：
$ ssh -v -i /cygdrive/c/data/copy/pk.pem ec2_user@host
OpenSSH_5.9p1, OpenSSL 0.9.8r 8 Feb 2011
debug1: Connecting to host [46.xx.xx.xx] port 22.
debug1: Connection established.
debug1: identity file /cygdrive/c/data/copy/pk.pem type -1
debug1: identity file /cygdrive/c/data/copy/pk.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_5.9
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: Server host key: RSA 44:xx:xx:xx
debug1: Host 'host' is known and matches the RSA host key.
debug1: Found key in /home/a25058/.ssh/known_hosts:9
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: Trying private key: /cygdrive/c/data/copy/pk.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).
造成这种情况的可能原因是什么？
答案1
问题已解决：
我使用了错误的用户名。尝试以 root 身份登录时显示以下错误：
Please login as the ec2-user user rather than root user.
显然，即使在 Amazon AMI 中，用户命名约定也不一致 - 有些使用 ec2_user，有些使用 ec2-user。