我多年来一直使用 SSH 连接到我的 Synology。最近，我生成了一个新id_rsa密钥并将公钥复制到 Synology 的.ssh/authorized_keys.不幸的是，新密钥总是提示输入密码：
❯ ssh -vvv nas
OpenSSH_8.1p1, LibreSSL 2.7.3
debug1: Reading configuration data /Users/andig/.ssh/config
debug1: /Users/andig/.ssh/config line 14: Applying options for nas
debug1: /Users/andig/.ssh/config line 68: Applying options for *
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 47: Applying options for *
debug1: Connecting to nas port 22.
debug1: Connection established.
debug1: identity file /Users/andig/.ssh/id_rsa type 0
debug1: identity file /Users/andig/.ssh/id_rsa-cert type -1
debug1: identity file /Users/andig/.ssh/id_dsa type -1
debug1: identity file /Users/andig/.ssh/id_dsa-cert type -1
debug1: identity file /Users/andig/.ssh/id_ecdsa type -1
debug1: identity file /Users/andig/.ssh/id_ecdsa-cert type -1
debug1: identity file /Users/andig/.ssh/id_ed25519 type -1
debug1: identity file /Users/andig/.ssh/id_ed25519-cert type -1
debug1: identity file /Users/andig/.ssh/id_xmss type -1
debug1: identity file /Users/andig/.ssh/id_xmss-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.1
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.4
debug1: match: OpenSSH_7.4 pat OpenSSH_7.0*,OpenSSH_7.1*,OpenSSH_7.2*,OpenSSH_7.3*,OpenSSH_7.4*,OpenSSH_7.5*,OpenSSH_7.6*,OpenSSH_7.7* compat 0x04000002
debug3: fd 5 is O_NONBLOCK
debug1: Authenticating to nas:22 as 'admin'
debug3: hostkeys_foreach: reading file "/Users/andig/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /Users/andig/.ssh/known_hosts:13
debug3: load_hostkeys: loaded 1 keys from nas
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-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],[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]
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],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: curve25519-sha256,[email protected],diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1,diffie-hellman-group14-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521
debug2: host key algorithms: ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256,ssh-ed25519
debug2: ciphers ctos: aes128-ctr,[email protected],aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: ciphers stoc: aes128-ctr,[email protected],aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: MACs ctos: hmac-sha1,[email protected],hmac-sha2-256,[email protected],hmac-sha2-512,[email protected],[email protected],[email protected],[email protected],[email protected]
debug2: MACs stoc: hmac-sha1,[email protected],hmac-sha2-256,[email protected],hmac-sha2-512,[email protected],[email protected],[email protected],[email protected],[email protected]
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: curve25519-sha256
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:a4IWJIsXBhxFEclMSEupFvwvybft5WI8xb8R/8/DhO8
debug3: hostkeys_foreach: reading file "/Users/andig/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /Users/andig/.ssh/known_hosts:13
debug3: load_hostkeys: loaded 1 keys from nas
debug3: hostkeys_foreach: reading file "/Users/andig/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /Users/andig/.ssh/known_hosts:22
debug3: load_hostkeys: loaded 1 keys from 192.168.0.41
debug1: Host 'nas' is known and matches the ECDSA host key.
debug1: Found key in /Users/andig/.ssh/known_hosts:13
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey out 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 in after 134217728 blocks
debug1: Will attempt key: /Users/andig/.ssh/id_rsa RSA SHA256:xlawB7MAGNbHr5bGC7vIEag9s9tjfOo7Jc9ERHbJ6X8
debug1: Will attempt key: /Users/andig/.ssh/id_dsa
debug1: Will attempt key: /Users/andig/.ssh/id_ecdsa
debug1: Will attempt key: /Users/andig/.ssh/id_ed25519
debug1: Will attempt key: /Users/andig/.ssh/id_xmss
debug2: pubkey_prepare: done
debug3: send packet: type 5
debug3: receive packet: type 7
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<ssh-ed25519,ssh-rsa,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521>
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,password
debug3: start over, passed a different list publickey,password
debug3: preferred 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: Offering public key: /Users/andig/.ssh/id_rsa RSA SHA256:xlawB7MAGNbHr5bGC7vIEag9s9tjfOo7Jc9ERHbJ6X8
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,password
debug1: Trying private key: /Users/andig/.ssh/id_dsa
debug3: no such identity: /Users/andig/.ssh/id_dsa: No such file or directory
debug1: Trying private key: /Users/andig/.ssh/id_ecdsa
debug3: no such identity: /Users/andig/.ssh/id_ecdsa: No such file or directory
debug1: Trying private key: /Users/andig/.ssh/id_ed25519
debug3: no such identity: /Users/andig/.ssh/id_ed25519: No such file or directory
debug1: Trying private key: /Users/andig/.ssh/id_xmss
debug3: no such identity: /Users/andig/.ssh/id_xmss: No such file or directory
debug2: we did not send a packet, disable method
debug3: authmethod_lookup password
debug3: remaining preferred: ,password
debug3: authmethod_is_enabled password
debug1: Next authentication method: password
admin@nas's password:
切换回旧密钥效果很好。不同机器（Raspi）上的新密钥也可以正常工作。
我无法弄清楚为什么新密钥在 Syno 上不起作用？
答案1
事实证明authorized_keys文件已损坏：
ssh-rsa AAAAB3NzaC1y...
ssh-dss AAAAB3NzaC1k...
ssh-rsa
AAAAB3NzaC1yc2EAA...
ssh-rsa
AAAAB3NzaC1...
似乎只是粘贴密钥确实在密钥类型标识符后面引入了换行符。在使用nano该文件时，我首先没有注意到，因为它对我来说看起来像是一个自然的工作包装。