我正在努力更好地了解公钥/私钥是如何工作的。我知道发送方可以使用他/她的私钥向文档添加数字签名，从而实质上获得文档的哈希值，但我不理解的是如何使用公钥来验证该签名。

我的理解是公钥加密，私钥解密…有人能帮我理解一下吗?

我在authorized_keys文件中添加了公共SSH密钥。SSH localhost应该在不询问密码的情况下登录我。

我这样做了，并尝试输入ssh localhost，但它仍然要求我输入密码。我是否还需要经过另一个设置才能使它生效?

我已经按照说明更改权限:

下面是执行ssh -v localhost的结果。

debug1: Reading configuration data /home/john/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to localhost [127.0.0.1] port 22.
debug1: Connection established.
debug1: identity file /home/john/.ssh/identity type 1
debug1: identity file /home/john/.ssh/id_rsa type -1
debug1: identity file /home/john/.ssh/id_dsa type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_4.7p1 Debian-8ubuntu3
debug1: match: OpenSSH_4.7p1 Debian-8ubuntu3 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_4.7p1 Debian-8ubuntu3
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-cbc hmac-md5 none
debug1: kex: client->server aes128-cbc 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: Host 'localhost' is known and matches the RSA host key.
debug1: Found key in /home/john/.ssh/known_hosts:12
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,password
debug1: Next authentication method: publickey
debug1: Offering public key: /home/john/.ssh/identity
debug1: Server accepts key: pkalg ssh-rsa blen 149
debug1: PEM_read_PrivateKey failed
debug1: read PEM private key done: type <unknown>

然后在上面的日志之后请求一个密码阶段。为什么不用密码就能登录?

我正在尝试使用以下命令行将代码部署到heroku：

git push heroku master

但会出现以下错误：

Permission denied (publickey).
fatal: The remote end hung up unexpectedly

我已经上传了我的公共SSH密钥，但仍然会出现此错误。

我用的是Mac雪豹，刚刚安装了git。

我只是试了

git clone git@thechaw.com:cakebook.git

但这给了我这个错误:

Initialized empty Git repository in `/Users/username/Documents/cakebook/.git/`
Permission denied (publickey).
fatal: The remote end hung up unexpectedly

我错过了什么? 我也试过做ssh-keygen没有密码，但仍然错误。