我是 ubuntu 的新手。因此，如果问题太简单，请原谅我。
我有一个使用亚马逊 ec2 实例的 ubuntu 服务器设置。我需要使用 SSH 将我的桌面（也是 ubuntu 机器）连接到 ubuntu 服务器。
我已经在 ubuntu 服务器中安装了 open-ssh。我需要我网络中的所有系统来使用 SSH 连接 ubuntu 服务器。因此，我在安全组 (AWS) 中为我的静态 IP 打开了 SSH 端口 22。
我的 SSHD-CONFIG 文件是：
# Package generated configuration file
# See the sshd_config(5) manpage for details
# What ports, IPs and protocols we listen for
Port 22
# Use these options to restrict which interfaces/protocols sshd will bind to
#ListenAddress ::
#ListenAddress 0.0.0.0
Protocol 2
# HostKeys for protocol version 2
HostKey /etc/ssh/ssh_host_rsa_key
HostKey /etc/ssh/ssh_host_dsa_key
HostKey /etc/ssh/ssh_host_ecdsa_key
#Privilege Separation is turned on for security
UsePrivilegeSeparation yes
# Lifetime and size of ephemeral version 1 server key
KeyRegenerationInterval 3600
ServerKeyBits 768
# Logging
SyslogFacility AUTH
LogLevel INFO
# Authentication:
LoginGraceTime 120
PermitRootLogin yes
StrictModes yes
RSAAuthentication yes
PubkeyAuthentication yes
#AuthorizedKeysFile %h/.ssh/authorized_keys
# Don't read the user's ~/.rhosts and ~/.shosts files
IgnoreRhosts yes
# For this to work you will also need host keys in /etc/ssh_known_hosts
RhostsRSAAuthentication no
# similar for protocol version 2
HostbasedAuthentication no
# Uncomment if you don't trust ~/.ssh/known_hosts for RhostsRSAAuthentication
#IgnoreUserKnownHosts yes
# To enable empty passwords, change to yes (NOT RECOMMENDED)
PermitEmptyPasswords no
# Change to yes to enable challenge-response passwords (beware issues with
# some PAM modules and threads)
ChallengeResponseAuthentication no
# Change to no to disable tunnelled clear text passwords
#PasswordAuthentication yes
# Kerberos options
#KerberosAuthentication no
#KerberosGetAFSToken no
#KerberosOrLocalPasswd yes
#KerberosTicketCleanup yes
# GSSAPI options
#GSSAPIAuthentication no
#GSSAPICleanupCredentials yes
X11Forwarding yes
X11DisplayOffset 10
PrintMotd no
PrintLastLog yes
TCPKeepAlive yes
#UseLogin no
#MaxStartups 10:30:60
#Banner /etc/issue.net
# Allow client to pass locale environment variables
AcceptEnv LANG LC_*
Subsystem sftp /usr/lib/openssh/sftp-server
# Set this to 'yes' to enable PAM authentication, account processing,
# and session processing. If this is enabled, PAM authentication will
# be allowed through the ChallengeResponseAuthentication and
# PasswordAuthentication. Depending on your PAM configuration,
# PAM authentication via ChallengeResponseAuthentication may bypass
# the setting of "PermitRootLogin without-password".
# If you just want the PAM account and session checks to run without
# PAM authentication, then enable this but set PasswordAuthentication
# and ChallengeResponseAuthentication to 'no'.
UsePAM yes
现在，当我尝试从终端连接 ubuntu 服务器时，
ssh ubuntu@SERVER_IP
我收到以下错误：
Permission denied, please try again.
在一些研究中，我意识到，我需要为此监视服务器的身份验证日志。我的身份验证日志 (/var/log/auth.log) 中出现以下错误
Jul 2 09:38:07 ip-192-xx-xx-xxx sshd[3037]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=MY_CLIENT_IP user=ubuntu
Jul 2 09:38:09 ip-192-xx-xx-xxx sshd[3037]: Failed password for ubuntu from MY_CLIENT_IP port 39116 ssh2
当我尝试使用以下命令进行调试时： ssh -v ubuntu@SERVER_IP
OpenSSH_5.9p1 Debian-5ubuntu1, OpenSSL 1.0.1 14 Mar 2012
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to SERVER_IP [SERVER_IP] port 22.
debug1: Connection established.
debug1: identity file {MY-WORKSPACE}/.ssh/id_rsa type 1
debug1: Checking blacklist file /usr/share/ssh/blacklist.RSA-2048
debug1: Checking blacklist file /etc/ssh/blacklist.RSA-2048
debug1: identity file {MY-WORKSPACE}/.ssh/id_rsa-cert type -1
debug1: identity file {MY-WORKSPACE}/.ssh/id_dsa type -1
debug1: identity file {MY-WORKSPACE}/.ssh/id_dsa-cert type -1
debug1: identity file {MY-WORKSPACE}/.ssh/id_ecdsa type -1
debug1: identity file {MY-WORKSPACE}/.ssh/id_ecdsa-cert type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.8p1 Debian-7ubuntu1
debug1: match: OpenSSH_5.8p1 Debian-7ubuntu1 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.9p1 Debian-5ubuntu1
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: sending SSH2_MSG_KEX_ECDH_INIT
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ECDSA {SERVER_HOST_KEY}
debug1: Host 'SERVER_IP' is known and matches the ECDSA host key.
debug1: Found key in {MY-WORKSPACE}/.ssh/known_hosts:1
debug1: ssh_ecdsa_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: password
debug1: Next authentication method: password
ubuntu@SERVER_IP's password:
debug1: Authentications that can continue: password
Permission denied, please try again.
ubuntu@SERVER_IP's password:
谁能指导我问题出在哪里，并为此问题提出一些解决方案。
谢谢你。