我遵循本指南使用PyMongo进行自签名SSL连接，由Wan Bachtiar创建了三个.pem文件；server.pem、client.pem和ca.pem。
我使用的是Ubuntu 16.04和MongoDB v3.2.11。
目的是在将MongoDB开放到公共互联网之前确保其安全。
让我们启动mongod:
$ mongod --auth --port 27017 --dbpath /data/db1
--sslMode requireSSL --sslPEMKeyFile /etc/ssl/server.pem
--sslCAFile /etc/ssl/ca.pem --sslAllowInvalidHostnames &
输出：
root@tim:/etc/ssl# 2017-01-13T12:58:55.150+0000 I CONTROL [initandlisten] MongoDB starting : pid=19058 port=27017 dbpath=/data/db1 64-bit host=tim
2017-01-13T12:58:55.150+0000 I CONTROL [initandlisten] db version v3.2.11
2017-01-13T12:58:55.151+0000 I CONTROL [initandlisten] git version: 009580ad490190ba33d1c6253ebd8d91808923e4
2017-01-13T12:58:55.151+0000 I CONTROL [initandlisten] OpenSSL version: OpenSSL 1.0.2g 1 Mar 2016
2017-01-13T12:58:55.152+0000 I CONTROL [initandlisten] allocator: tcmalloc
2017-01-13T12:58:55.152+0000 I CONTROL [initandlisten] modules: none
2017-01-13T12:58:55.152+0000 I CONTROL [initandlisten] build environment:
2017-01-13T12:58:55.152+0000 I CONTROL [initandlisten] distmod: ubuntu1604
2017-01-13T12:58:55.152+0000 I CONTROL [initandlisten] distarch: x86_64
2017-01-13T12:58:55.152+0000 I CONTROL [initandlisten] target_arch: x86_64
2017-01-13T12:58:55.153+0000 I CONTROL [initandlisten] options: { net: { port: 27017, ssl: { CAFile: "/etc/ssl/ca.pem", PEMKeyFile: "/etc/ssl/server.pem", allowInvalidHostnames: true, mode: "requireSSL" }
}, security: { authorization: "enabled" }, storage: { dbPath: "/data/db1" } }
2017-01-13T12:58:55.211+0000 I - [initandlisten] Detected data files in /data/db1 created by the 'wiredTiger' storage engine, so setting the active storage engine to 'wiredTiger'.
2017-01-13T12:58:55.212+0000 W - [initandlisten] Detected unclean shutdown - /data/db1/mongod.lock is not empty.
2017-01-13T12:58:55.212+0000 W STORAGE [initandlisten] Recovering data from the last clean checkpoint.
2017-01-13T12:58:55.212+0000 I STORAGE [initandlisten] wiredtiger_open config: create,cache_size=1G,session_max=20000,eviction=(threads_max=4)
,config_base=false,statistics=(fast),log=(enabled=true,archive=true,path=journal,compressor=snappy),file_manager=(close_idle_time=100000),checkpoint=(wait=60,log_size=2GB),statistics_log=(wait=0),
2017-01-13T12:58:55.886+0000 I CONTROL [initandlisten] ** WARNING: You are running this process as the root user, which is not recommended.
2017-01-13T12:58:55.886+0000 I CONTROL [initandlisten]
2017-01-13T12:58:55.895+0000 I FTDC [initandlisten] Initializing full-time diagnostic data capture with directory '/data/db1/diagnostic.data'
2017-01-13T12:58:55.897+0000 I NETWORK [initandlisten] waiting for connections on port 27017 ssl
2017-01-13T12:58:55.897+0000 I NETWORK [HostnameCanonicalizationWorker] Starting hostname canonicalization worker
2017-01-13T12:58:56.026+0000 I FTDC [ftdc] Unclean full-time diagnostic data capture shutdown detected, found interim file, some metrics may have been lost. OK
运行mongod后，我启动mongoshell：
$ mongo --port 27017 -u "my username" -p "my password"
--authenticationDatabase "" --ssl --sslPEMKeyFile /etc/ssl/client.pem
--sslCAFile /etc/ssl/ca.pem --host tim
产出与Marshall Farrier的问题类似；让我们看看。
MongoDB shell version: 3.2.11
connecting to: 127.0.0.1:27017/datatest
2017-01-13T12:35:58.247+0000 I NETWORK [initandlisten] connection accepted from 127.0.0.1:38902 #8 (1 connection now open)
2017-01-13T12:35:58.259+0000 E NETWORK [thread1] SSL peer certificate validation failed: self signed certificate
2017-01-13T12:35:58.259+0000 E QUERY [thread1] Error: socket exception [CONNECT_ERROR] for SSL peer certificate validation failed: self signed certificate :
connect@src/mongo/shell/mongo.js:231:14
@(connect):1:6
2017-01-13T12:35:58.263+0000 E NETWORK [conn8] SSL peer certificate validation failed: self signed certificate
2017-01-13T12:35:58.263+0000 I NETWORK [conn8] end connection 127.0.0.1:38902 (0 connections now open)
我做错了什么？
经过一些搜索，这个错误似乎是由于主机名"CN"不正确。
来自digitalocean：
每当您生成CSR时，系统都会提示您提供有关证书的信息。这些信息被称为Distinguisized Name(DN)。DN中的一个重要字段是公用名(CN)，它应该是要与之一起使用证书的主机的完全限定域名(FQDN)。
同样来自MongoDB文档：
如果MongoDB部署使用SSL，则还必须指定--host选项。mongo验证您要连接的mongod或mongos的主机名是否与mongod的--sslPEMKeyFile证书的CN或SAN匹配。如果主机名与CN/SAN不匹配，mongo将无法连接。
解决方案：
我重新生成了密钥，将localhost替换为CN=<主机名>并完成了Wan Bachtiar的指南。
完成后运行以下命令有效：
$ mongo --port 27017 -u '<_username_>' -p '<_password_>'
--authenticationDatabase "<_my db_>" --ssl --sslPEMKeyFile
/etc/ssl/client.pem --sslCAFile /etc/ssl/ca.pem --host localhost
注：MongoDB遵循一个严格的规则，即谁可以访问什么数据库，这是mongo shell中的一个快速测试：
>显示dbs
返回一个错误。然而，我的用户实际上只能访问"<my db>"中指定的数据库，因此在"<my-db>"中的行之间循环非常有效。