我刚刚生成了一个 ECDSA 密钥ssh-keygen：
ssh-keygen -t ecdsa -b 521
然后我继续将此密钥复制到我的服务器：
cat .ssh/id_ecdsa.pub | ssh myserver "tee -a .ssh/authorized_keys"
我已经确认我的密钥在文件中。
但是，当我尝试连接时，我的连接被拒绝：
ssh -v -i .ssh/id_ecdsa myserver
日志：
OpenSSH_5.9p1 Debian-5ubuntu1.1, 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 myserver [192.168.1.1] port 22.
debug1: Connection established.
debug1: identity file .ssh/id_ecdsa type 3
debug1: Checking blacklist file /usr/share/ssh/blacklist.ECDSA-521
debug1: Checking blacklist file /etc/ssh/blacklist.ECDSA-521
debug1: identity file .ssh/id_ecdsa-cert type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.1
debug1: match: OpenSSH_6.1 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.9p1 Debian-5ubuntu1.1
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 10:27:b8:78:2c:e1:e3:42:8e:e3:66:c4:cc:4e:f1:c0
debug1: Host 'myserver' is known and matches the RSA host key.
debug1: Found key in /home/naftuli/.ssh/known_hosts:73
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 ECDSA public key: .ssh/id_ecdsa
debug1: Authentications that can continue: publickey
debug1: No more authentication methods to try.
Permission denied (publickey).
在服务器日志中发现：
auth.info sshd[13874]: userauth_pubkey: unsupported public key algorithm: ecdsa-sha2-nistp521 [preauth]
我的客户端和服务器都在使用 OpenSSH。服务器的 OpenSSH 版本是 OpenSSH 6.1，我客户端的 OpenSSH 版本是 OpenSSH 5.9。
我如何知道我的服务器支持哪些关键算法？
与许多其他嵌入式系统一样，OpenWrt 使用dropbear作为其 ssh 服务器，而不是 Linux 系统上常见的重量级 OpenSSH。旧版本的 dropbear 仅支持 RSA 和 DSA 密钥；直到版本 2013.62（几天前才发布）才添加了对 ECDSA 的支持。
它应该很快就会出现在 Barrier Breaker (trunk) 中；但你不会在态度调整中看到它。
ecdsa从openssh-server 版本 5.7开始支持。您正在运行什么版本的 openssh-server？运行dpkg -l | grep openssh-server | awk '{print $3}' | cut -d: -f2查找版本。