沃通及其收购的startssl证书被封，用不了，只能申请Let's Encrypt免费证书，我就不科普了，免费是免费，时效只有3个月，就得更新，就是这样，喵
到下面的网站，一下脚本，可以助力你快速申请证书
https://certbot.eff.org/
下面以centos 6 - nginx 为例：
打开https://certbot.eff.org/
选好系统版本，即下面的URL
https://certbot.eff.org/#centos6-nginx
1、下载
wget -O /sbin/certbot https://dl.eff.org/certbot-auto chmod a+x /sbin/certbot
2、修改nginx主机配置文件（vhost则配置在vhost配置文件上）配置在第一个location匹配规则上
location ^~ /.well-known/acme-challenge/ {
default_type "text/plain";
root /path/website/;
}
location = /.well-known/acme-challenge/ {
return 404;
}
重新加载生效：server nginx reload
3、申请证书
certbot certonly --email mail@example.com --agree-tos --no-eff-email --webroot -w /path/website -d www.example.com
申请的证书一般都会在/etc/letsencrypt/live/example.com/ 下，会有下面5个文件 #注意example为你的网站名
cert.pem chain.pem fullchain.pem privkey.pem README
4、为NGINX添加SSL
我的nginx 为源码安装/usr/local/nginx下
创建sslkey保存目录
[root@localhost sslkey]#mkdir -pv /usr/local/nginx/conf/sslkey
[root@localhost sslkey]#cd /usr/local/nginx/conf/sslkey
[root@localhost sslkey]#ln -s /etc/letsencrypt/live/example.com/* ./
[root@localhost sslkey]# ll
total 0
lrwxrwxrwx 1 root root 42 Jun 27 17:06 cert.pem -> /etc/letsencrypt/live/example.com/cert.pem
lrwxrwxrwx 1 root root 43 Jun 27 17:06 chain.pem -> /etc/letsencrypt/live/example.com/chain.pem
lrwxrwxrwx 1 root root 47 Jun 27 17:06 fullchain.pem -> /etc/letsencrypt/live/example.com/fullchain.pem
lrwxrwxrwx 1 root root 45 Jun 27 17:06 privkey.pem -> /etc/letsencrypt/live/example.com/privkey.pem
lrwxrwxrwx 1 root root 40 Jun 27 17:06 README -> /etc/letsencrypt/live/example.com/README
[root@localhost sslkey]# ls
cert.pem chain.pem fullchain.pem privkey.pem README
[root@localhost sslkey]# pwd
/usr/local/nginx/conf/sslkey
[root@localhost sslkey]#
5、修改nginx主机配置文件（vhost则配置在vhos配置文件上）添加ssl支持,例如下面的
listen 80;
listen 443 ssl;
server_name www.example.com;
root /path/website/;
index index.php index.htm index.html;
ssl on;
ssl_certificate /usr/local/nginx/conf/sslkey/cert.pem;
ssl_certificate_key /usr/local/nginx/conf/sslkey/privkey.pem;
ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
ssl_ciphers ALL:!DH:!EXPORT:!RC4:+HICH:+MEDIUM:!LOW:!aNULL:!eNULL;
......
重启生效
访问HTTPS没毛病
6、由于只有90天就得更新证书，而且只有在7天内的过期的才能更新，所以得把证书更新添加到计划任务,时间根据需要设置
#crontab -e
00 00 00 */3 * /sbin/certbot renew --renew-hook "service nginx reload" --quiet > /dev/null 2>&1 &
7、回收证书
certbot revoke --cert-path /etc/letsencrypt/live/example.com/cert.pem
certbot delete --cert-name example.com
8、 cerbot扩展，可以扮发多路径多域名证书，多路径单域名暂时没有看到，你看得到话留言吧
执行
#certbot -h all
usage:
certbot-auto [SUBCOMMAND] [options] [-d DOMAIN] [-d DOMAIN] ...
Certbot can obtain and install HTTPS/TLS/SSL certificates. By default,
it will attempt to use a webserver both for obtaining and installing the
certificate. The most common SUBCOMMANDS and flags are:
obtain, install, and renew certificates:
(default) run Obtain & install a certificate in your current webserver
certonly Obtain or renew a certificate, but do not install it
renew Renew all previously obtained certificates that are near expiry
-d DOMAINS Comma-separated list of domains to obtain a certificate for
--apache Use the Apache plugin for authentication & installation
--standalone Run a standalone webserver for authentication
--nginx Use the Nginx plugin for authentication & installation
--webroot Place files in a server's webroot folder for authentication
--manual Obtain certificates interactively, or using shell script hooks
-n Run non-interactively
--test-cert Obtain a test certificate from a staging server
--dry-run Test "renew" or "certonly" without saving any certificates to disk
manage certificates:
certificates Display information about certificates you have from Certbot
revoke Revoke a certificate (supply --cert-path)
delete Delete a certificate
manage your account with Let's Encrypt:
register Create a Let's Encrypt ACME account
--agree-tos Agree to the ACME server's Subscriber Agreement
-m EMAIL Email address for important account notifications
optional arguments:
-h, --help show this help message and exit
-c CONFIG_FILE, --config CONFIG_FILE
path to config file (default: /etc/letsencrypt/cli.ini
and ~/.config/letsencrypt/cli.ini)
-v, --verbose This flag can be used multiple times to incrementally
increase the verbosity of output, e.g. -vvv. (default:
-2)
-n, --non-interactive, --noninteractive
Run without ever asking for user input. This may
require additional command line flags; the client will
try to explain which ones are required if it finds one
missing (default: False)
--force-interactive Force Certbot to be interactive even if it detects
it's not being run in a terminal. This flag cannot be
used with the renew subcommand. (default: False)
-d DOMAIN, --domains DOMAIN, --domain DOMAIN
Domain names to apply. For multiple domains you can
use multiple -d flags or enter a comma separated list
of domains as a parameter. (default: Ask)
--cert-name CERTNAME Certificate name to apply. Only one certificate name
can be used per Certbot run. To see certificate names,
run 'certbot certificates'. When creating a new
certificate, specifies the new certificate's name.
(default: None)
--dry-run Perform a test run of the client, obtaining test
(invalid) certificates but not saving them to disk.
This can currently only be used with the 'certonly'
and 'renew' subcommands. Note: Although --dry-run
tries to avoid making any persistent changes on a
system, it is not completely side-effect free: if used
with webserver authenticator plugins like apache and
nginx, it makes and then reverts temporary config
changes in order to obtain test certificates, and
reloads webservers to deploy and then roll back those
changes. It also calls --pre-hook and --post-hook
commands if they are defined because they may be
necessary to accurately simulate renewal. --renew-hook
commands are not called. (default: False)
--debug-challenges After setting up challenges, wait for user input
before submitting to CA (default: False)
--preferred-challenges PREF_CHALLS
A sorted, comma delimited list of the preferred
challenge to use during authorization with the most
preferred challenge listed first (Eg, "dns" or "tls-
sni-01,http,dns"). Not all plugins support all
challenges. See
https://certbot.eff.org/docs/using.html#plugins for
details. ACME Challenges are versioned, but if you
pick "http" rather than "http-01", Certbot will select
the latest version automatically. (default: [])
--user-agent USER_AGENT
Set a custom user agent string for the client. User
agent strings allow the CA to collect high level
statistics about success rates by OS, plugin and use
case, and to know when to deprecate support for past
Python versions and flags. If you wish to hide this
information from the Let's Encrypt server, set this to
"". (default: CertbotACMEClient/0.15.0 (certbot-auto;
CentOS 6.6) Authenticator/XXX Installer/YYY
(SUBCOMMAND; flags: FLAGS) Py/2.6.6). The flags
encoded in the user agent are: --duplicate, --force-
renew, --allow-subset-of-names, -n, and whether any
hooks are set.
automation:
Arguments for automating execution & other tweaks
--keep-until-expiring, --keep, --reinstall
If the requested certificate matches an existing
certificate, always keep the existing one until it is
due for renewal (for the 'run' subcommand this means
reinstall the existing certificate). (default: Ask)
--expand If an existing certificate is a strict subset of the
requested names, always expand and replace it with the
additional names. (default: Ask)
--version show program's version number and exit
--force-renewal, --renew-by-default
If a certificate already exists for the requested
domains, renew it now, regardless of whether it is
near expiry. (Often --keep-until-expiring is more
appropriate). Also implies --expand. (default: False)
--renew-with-new-domains
If a certificate already exists for the requested
certificate name but does not match the requested
domains, renew it now, regardless of whether it is
near expiry. (default: False)
--allow-subset-of-names
When performing domain validation, do not consider it
a failure if authorizations can not be obtained for a
strict subset of the requested domains. This may be
useful for allowing renewals for multiple domains to
succeed even if some domains no longer point at this
system. This option cannot be used with --csr.
(default: False)
--agree-tos Agree to the ACME Subscriber Agreement (default: Ask)
--duplicate Allow making a certificate lineage that duplicates an
existing one (both can be renewed in parallel)
(default: False)
--os-packages-only (certbot-auto only) install OS package dependencies
and then stop (default: False)
--no-self-upgrade (certbot-auto only) prevent the certbot-auto script
from upgrading itself to newer released versions
(default: Upgrade automatically)
--no-bootstrap (certbot-auto only) prevent the certbot-auto script
from installing OS-level dependencies (default: Prompt
to install OS-wide dependencies, but exit if the user
says 'No')
-q, --quiet Silence all output except errors. Useful for
automation via cron. Implies --non-interactive.
(default: False)
security:
Security parameters & server settings
--rsa-key-size N Size of the RSA key. (default: 2048)
--must-staple Adds the OCSP Must Staple extension to the
certificate. Autoconfigures OCSP Stapling for
supported setups (Apache version >= 2.3.3 ). (default:
False)
--redirect Automatically redirect all HTTP traffic to HTTPS for
the newly authenticated vhost. (default: Ask)
--no-redirect Do not automatically redirect all HTTP traffic to
HTTPS for the newly authenticated vhost. (default:
Ask)
--hsts Add the Strict-Transport-Security header to every HTTP
response. Forcing browser to always use SSL for the
domain. Defends against SSL Stripping. (default:
False)
--uir Add the "Content-Security-Policy: upgrade-insecure-
requests" header to every HTTP response. Forcing the
browser to use https:// for every http:// resource.
(default: None)
--staple-ocsp Enables OCSP Stapling. A valid OCSP response is
stapled to the certificate that the server offers
during TLS. (default: None)
--strict-permissions Require that all configuration files are owned by the
current user; only needed if your config is somewhere
unsafe like /tmp/ (default: False)
testing:
The following flags are meant for testing and integration purposes only.
--test-cert, --staging
Use the staging server to obtain or revoke test
(invalid) certificates; equivalent to --server https
://acme-staging.api.letsencrypt.org/directory
(default: False)
--debug Show tracebacks in case of errors, and allow certbot-
auto execution on experimental platforms (default:
False)
--no-verify-ssl Disable verification of the ACME server's certificate.
(default: False)
--tls-sni-01-port TLS_SNI_01_PORT
Port used during tls-sni-01 challenge. This only
affects the port Certbot listens on. A conforming ACME
server will still attempt to connect on port 443.
(default: 443)
--tls-sni-01-address TLS_SNI_01_ADDRESS
The address the server listens to during tls-sni-01
challenge. (default: )
--http-01-port HTTP01_PORT
Port used in the http-01 challenge. This only affects
the port Certbot listens on. A conforming ACME server
will still attempt to connect on port 80. (default:
80)
--http-01-address HTTP01_ADDRESS
The address the server listens to during http-01
challenge. (default: )
--break-my-certs Be willing to replace or renew valid certificates with
invalid (testing/staging) certificates (default:
False)
paths:
Arguments changing execution paths & servers
--cert-path CERT_PATH
Path to where certificate is saved (with auth --csr),
installed from, or revoked. (default: None)
--key-path KEY_PATH Path to private key for certificate installation or
revocation (if account key is missing) (default: None)
--fullchain-path FULLCHAIN_PATH
Accompanying path to a full certificate chain
(certificate plus chain). (default: None)
--chain-path CHAIN_PATH
Accompanying path to a certificate chain. (default:
None)
--config-dir CONFIG_DIR
Configuration directory. (default: /etc/letsencrypt)
--work-dir WORK_DIR Working directory. (default: /var/lib/letsencrypt)
--logs-dir LOGS_DIR Logs directory. (default: /var/log/letsencrypt)
--server SERVER ACME Directory Resource URI. (default:
https://acme-v01.api.letsencrypt.org/directory)
manage:
Various subcommands and flags are available for managing your
certificates:
certificates List certificates managed by Certbot
delete Clean up all files related to a certificate
renew Renew all certificates (or one specified with --cert-
name)
revoke Revoke a certificate specified with --cert-path
update_symlinks Recreate symlinks in your /etc/letsencrypt/live/
directory
run:
Options for obtaining & installing certificates
certonly:
Options for modifying how a certificate is obtained
--csr CSR Path to a Certificate Signing Request (CSR) in DER or
PEM format. Currently --csr only works with the
'certonly' subcommand. (default: None)
renew:
The 'renew' subcommand will attempt to renew all certificates (or more
precisely, certificate lineages) you have previously obtained if they are
close to expiry, and print a summary of the results. By default, 'renew'
will reuse the options used to create obtain or most recently successfully
renew each certificate lineage. You can try it with `--dry-run` first. For
more fine-grained control, you can renew individual lineages with the
`certonly` subcommand. Hooks are available to run commands before and
after renewal; see https://certbot.eff.org/docs/using.html#renewal for
more information on these.
--pre-hook PRE_HOOK Command to be run in a shell before obtaining any
certificates. Intended primarily for renewal, where it
can be used to temporarily shut down a webserver that
might conflict with the standalone plugin. This will
only be called if a certificate is actually to be
obtained/renewed. When renewing several certificates
that have identical pre-hooks, only the first will be
executed. (default: None)
--post-hook POST_HOOK
Command to be run in a shell after attempting to
obtain/renew certificates. Can be used to deploy
renewed certificates, or to restart any servers that
were stopped by --pre-hook. This is only run if an
attempt was made to obtain/renew a certificate. If
multiple renewed certificates have identical post-
hooks, only one will be run. (default: None)
--renew-hook RENEW_HOOK
Command to be run in a shell once for each
successfully renewed certificate. For this command,
the shell variable $RENEWED_LINEAGE will point to the
config live subdirectory (for example,
"/etc/letsencrypt/live/example.com") containing the
new certificates and keys; the shell variable
$RENEWED_DOMAINS will contain a space-delimited list
of renewed certificate domains (for example,
"example.com www.example.com" (default: None)
--disable-hook-validation
Ordinarily the commands specified for --pre-hook
/--post-hook/--renew-hook will be checked for
validity, to see if the programs being run are in the
$PATH, so that mistakes can be caught early, even when
the hooks aren't being run just yet. The validation is
rather simplistic and fails if you use more advanced
shell constructs, so you can use this switch to
disable it. (default: False)
certificates:
List certificates managed by Certbot
delete:
Options for deleting a certificate
revoke:
Options for revocation of certificates
--reason {keycompromise,affiliationchanged,superseded,unspecified,cessationofoperation}
Specify reason for revoking certificate. (default: 0)
register:
Options for account registration & modification
--register-unsafely-without-email
Specifying this flag enables registering an account
with no email address. This is strongly discouraged,
because in the event of key loss or account compromise
you will irrevocably lose access to your account. You
will also be unable to receive notice about impending
expiration or revocation of your certificates. Updates
to the Subscriber Agreement will still affect you, and
will be effective 14 days after posting an update to
the web site. (default: False)
--update-registration
With the register verb, indicates that details
associated with an existing registration, such as the
e-mail address, should be updated, rather than
registering a new account. (default: False)
-m EMAIL, --email EMAIL
Email used for registration and recovery contact.
(default: Ask)
--eff-email Share your e-mail address with EFF (default: None)
--no-eff-email Don't share your e-mail address with EFF (default:
None)
unregister:
Options for account deactivation.
--account ACCOUNT_ID Account ID to use (default: None)
install:
Options for modifying how a certificate is deployed
config_changes:
Options for controlling which changes are displayed
--num NUM How many past revisions you want to be displayed
(default: None)
rollback:
Options for rolling back server configuration changes
--checkpoints N Revert configuration N number of checkpoints.
(default: 1)
plugins:
Options for for the "plugins" subcommand
--init Initialize plugins. (default: False)
--prepare Initialize and prepare plugins. (default: False)
--authenticators Limit to authenticator plugins only. (default: None)
--installers Limit to installer plugins only. (default: None)
update_symlinks:
Recreates certificate and key symlinks in /etc/letsencrypt/live, if you
changed them by hand or edited a renewal configuration file
plugins:
Plugin Selection: Certbot client supports an extensible plugins
architecture. See 'certbot plugins' for a list of all installed plugins
and their names. You can force a particular plugin by setting options
provided below. Running --help <plugin_name> will list flags specific to
that plugin.
--configurator CONFIGURATOR
Name of the plugin that is both an authenticator and
an installer. Should not be used together with
--authenticator or --installer. (default: Ask)
-a AUTHENTICATOR, --authenticator AUTHENTICATOR
Authenticator plugin name. (default: None)
-i INSTALLER, --installer INSTALLER
Installer plugin name (also used to find domains).
(default: None)
--apache Obtain and install certificates using Apache (default:
False)
--nginx Obtain and install certificates using Nginx (default:
False)
--standalone Obtain certificates using a "standalone" webserver.
(default: False)
--manual Provide laborious manual instructions for obtaining a
certificate (default: False)
--webroot Obtain certificates by placing files in a webroot
directory. (default: False)
--dns-cloudflare Obtain certificates using a DNS TXT record (if you are
using Cloudflare for DNS). (default: False)
--dns-cloudxns Obtain certificates using a DNS TXT record (if you are
using CloudXNS for DNS). (default: False)
--dns-digitalocean Obtain certificates using a DNS TXT record (if you are
using DigitalOcean for DNS). (default: False)
--dns-dnsimple Obtain certificates using a DNS TXT record (if you are
using DNSimple for DNS). (default: False)
--dns-google Obtain certificates using a DNS TXT record (if you are
using Google Cloud DNS). (default: False)
--dns-nsone Obtain certificates using a DNS TXT record (if you are
using NS1 for DNS). (default: False)
--dns-route53 Obtain certificates using a DNS TXT record (if you are
using Route53 for DNS). (default: False)
apache:
Apache Web Server plugin - Beta
--apache-enmod APACHE_ENMOD
Path to the Apache 'a2enmod' binary. (default: None)
--apache-dismod APACHE_DISMOD
Path to the Apache 'a2dismod' binary. (default: None)
--apache-le-vhost-ext APACHE_LE_VHOST_EXT
SSL vhost configuration extension. (default: -le-
ssl.conf)
--apache-server-root APACHE_SERVER_ROOT
Apache server root directory. (default: /etc/httpd)
--apache-vhost-root APACHE_VHOST_ROOT
Apache server VirtualHost configuration root (default:
/etc/httpd/conf.d)
--apache-logs-root APACHE_LOGS_ROOT
Apache server logs directory (default: /var/log/httpd)
--apache-challenge-location APACHE_CHALLENGE_LOCATION
Directory path for challenge configuration. (default:
/etc/httpd/conf.d)
--apache-handle-modules APACHE_HANDLE_MODULES
Let installer handle enabling required modules for
you.(Only Ubuntu/Debian currently) (default: False)
--apache-handle-sites APACHE_HANDLE_SITES
Let installer handle enabling sites for you.(Only
Ubuntu/Debian currently) (default: False)
manual:
Authenticate through manual configuration or custom shell scripts. When
using shell scripts, an authenticator script must be provided. The
environment variables available to this script are $CERTBOT_DOMAIN which
contains the domain being authenticated, $CERTBOT_VALIDATION which is the
validation string, and $CERTBOT_TOKEN which is the filename of the
resource requested when performing an HTTP-01 challenge. An additional
cleanup script can also be provided and can use the additional variable
$CERTBOT_AUTH_OUTPUT which contains the stdout output from the auth
script.
--manual-auth-hook MANUAL_AUTH_HOOK
Path or command to execute for the authentication
script (default: None)
--manual-cleanup-hook MANUAL_CLEANUP_HOOK
Path or command to execute for the cleanup script
(default: None)
--manual-public-ip-logging-ok
Automatically allows public IP logging (default: Ask)
nginx:
Nginx Web Server plugin - Alpha
--nginx-server-root NGINX_SERVER_ROOT
Nginx server root directory. (default: /etc/nginx)
--nginx-ctl NGINX_CTL
Path to the 'nginx' binary, used for 'configtest' and
retrieving nginx version number. (default: nginx)
null:
Null Installer
standalone:
Spin up a temporary webserver
webroot:
Place files in webroot directory
--webroot-path WEBROOT_PATH, -w WEBROOT_PATH
public_html / webroot path. This can be specified
multiple times to handle different domains; each
domain will have the webroot path that preceded it.
For instance: `-w /var/www/example -d example.com -d
www.example.com -w /var/www/thing -d thing.net -d
m.thing.net` (default: Ask)
--webroot-map WEBROOT_MAP
JSON dictionary mapping domains to webroot paths; this
implies -d for each entry. You may need to escape this
from your shell. E.g.: --webroot-map
'{"eg1.is,m.eg1.is":"/www/eg1/", "eg2.is":"/www/eg2"}'
This option is merged with, but takes precedence over,
-w / -d entries. At present, if you put webroot-map in
a config file, it needs to be on a single line, like:
webroot-map = {"example.com":"/var/www"}. (default:
{})