我曾尝试通过 ssh 连接到一个全新的 16.04 EC2 实例，但收到“权限被拒绝（公钥）”的提示。我可以使用相同的密钥访问新的 Amazon Linux 实例。在我看来，这是一个 sshd 问题，不喜欢我的密钥，但我不太清楚需要做什么来修复它（Amazon 似乎只能创建 256 位 RSA 密钥）。有什么建议吗？
$ ssh -Ai ~/.ssh/my-web.pem [email protected] -vvvv
OpenSSH_7.4p1 Ubuntu-10, OpenSSL 1.0.2g 1 Mar 2016
debug1: Reading configuration data /home/ivan/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug2: resolving "52.65.59.212" port 22
debug2: ssh_connect_direct: needpriv 0
debug1: Connecting to 52.65.59.212 [52.65.59.212] port 22.
debug1: Connection established.
debug1: key_load_public: No such file or directory
debug1: identity file /home/ivan/.ssh/my-web.pem type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ivan/.ssh/my-web.pem-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.4p1 Ubuntu-10
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2p2 Ubuntu-4ubuntu2.2
debug1: match: OpenSSH_7.2p2 Ubuntu-4ubuntu2.2 pat OpenSSH* compat 0x04000000
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to 52.65.59.212:22 as 'ec2-user'
debug3: hostkeys_foreach: reading file "/home/ivan/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /home/ivan/.ssh/known_hosts:163
debug3: load_hostkeys: loaded 1 keys from 52.65.59.212
debug3: order_hostkeyalgs: prefer hostkeyalgs: [email protected],[email protected],[email protected],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
debug3: receive packet: type 20
debug1: SSH2_MSG_KEXINIT received
debug2: local client KEXINIT proposal
debug2: KEX algorithms: curve25519-sha256,[email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1,ext-info-c
debug2: host key algorithms: [email protected],[email protected],[email protected],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[email protected],[email protected],ssh-ed25519,rsa-sha2-512,rsa-sha2-256,ssh-rsa
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected],aes128-cbc,aes192-cbc,aes256-cbc
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected],aes128-cbc,aes192-cbc,aes256-cbc
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[email protected],zlib
debug2: compression stoc: none,[email protected],zlib
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: [email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1
debug2: host key algorithms: ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256,ssh-ed25519
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[email protected]
debug2: compression stoc: none,[email protected]
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug1: kex: algorithm: [email protected]
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [email protected] MAC: <implicit> compression: none
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:dECkQyAas8mb3253fWWnbKyA5sKuHZW5f+WQmZcSQEE
debug3: hostkeys_foreach: reading file "/home/ivan/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /home/ivan/.ssh/known_hosts:163
debug3: load_hostkeys: loaded 1 keys from 52.65.59.212
debug1: Host '52.65.59.212' is known and matches the ECDSA host key.
debug1: Found key in /home/ivan/.ssh/known_hosts:163
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug1: SSH2_MSG_NEWKEYS received
debug2: set_newkeys: mode 0
debug1: rekey after 134217728 blocks
debug2: key: /home/ivan/.ssh/my-web.pem ((nil)), explicit
debug3: send packet: type 5
debug3: receive packet: type 7
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
debug3: receive packet: type 6
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug3: send packet: type 50
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey
debug3: start over, passed a different list publickey
debug3: preferred gssapi-keyex,gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /home/ivan/.ssh/my-web.pem
debug3: sign_and_send_pubkey: RSA SHA256:pLWmaHNdQ+BtGfxIr026FfbI2d2A+MH1khcRR+3QjsQ
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
Permission denied (publickey).
答案1
对于 Ubuntu，在 AWS EC2 中默认用户是ubuntu，因此您必须使用ubuntu@<ip>而不是ec2-user@<ip>。
这是您应该作为快速参考的常用列表：
ec2-user # (Amazon Linux, Red Hat Linux, SUSE Linux)
root # (Red Hat Linux, SUSE Linux)
ubuntu # (Ubuntu Linux distribution)
fedora # (Fedora Linux distribution)
答案2
问题出在公钥权限上。
400使用命令将其更改为
chmod 400 /home/ivan/.ssh/my-web.pem
再试一次。应该可以了。