问题:服务器和客户端证书必须由 SSL 中的同一个 CA 签名

我试图在 SSL 连接的上下文中了解客户端和服务器之间的关系。我是否正确理解相同的证书颁发机构(我 - 在下面的示例中)签署服务器和客户端证书的事实使得它们可以通信。因此,服务器仅在客户端使用由与服务器证书相同的 CA 签名的客户端证书进行身份验证时才接受通信,这对于 SSL 连接的想法至关重要?

(下面的脚本直接来自http://blog.nategood.com/client-side-certificate-authentication-in-ngi)

# Create the CA Key and Certificate for signing Client Certs
openssl genrsa -des3 -out ca.key 4096
openssl req -new -x509 -days 365 -key ca.key -out ca.crt

# Create the Server Key, CSR, and Certificate
openssl genrsa -des3 -out server.key 1024
openssl req -new -key server.key -out server.csr

# We're self signing our own server cert here.  This is a no-no in production.
openssl x509 -req -days 365 -in server.csr -CA ca.crt -CAkey ca.key -set_serial 01 -out server.crt

# Create the Client Key and CSR
openssl genrsa -des3 -out client.key 1024
openssl req -new -key client.key -out client.csr

# Sign the client certificate with our CA cert.  Unlike signing our own server cert, this is what we want to do.
openssl x509 -req -days 365 -in client.csr -CA ca.crt -CAkey ca.key -set_serial 01 -out client.crt

server {
    listen        443;
    ssl on;
    server_name example.com;

    ssl_certificate      /etc/nginx/certs/server.crt;
    ssl_certificate_key  /etc/nginx/certs/server.key;
    ssl_client_certificate /etc/nginx/certs/ca.crt;
    ssl_verify_client on;

解答

简短的回答是否定的。这是两个不同的方面。这里:

ssl_certificate      /etc/nginx/certs/server.crt;
ssl_certificate_key  /etc/nginx/certs/server.key;

您正在配置需要客户端信任的服务器证书。

和这里:

ssl_client_certificate /etc/nginx/certs/ca.crt;

您配置证书颁发机构来验证您的客户端的证书。