forked from TrueCloudLab/lego
256 lines
9.3 KiB
Markdown
256 lines
9.3 KiB
Markdown
# lego
|
|
Let's Encrypt client and ACME library written in Go
|
|
|
|
[](https://godoc.org/github.com/xenolf/lego/acme)
|
|
[](https://travis-ci.org/xenolf/lego)
|
|
[](https://gitter.im/xenolf/lego)
|
|
|
|
#### General
|
|
This is a work in progress. Please do *NOT* run this on a production server and please report any bugs you find!
|
|
|
|
#### Installation
|
|
lego supports both binary installs and install from source.
|
|
|
|
To get the binary just download the latest release for your OS/Arch from [the release page](https://github.com/xenolf/lego/releases)
|
|
and put the binary somewhere convenient. lego does not assume anything about the location you run it from.
|
|
|
|
To install from source, just run
|
|
```
|
|
go get -u github.com/xenolf/lego
|
|
```
|
|
|
|
#### Features
|
|
|
|
- Register with CA
|
|
- Obtain certificates
|
|
- Renew certificates
|
|
- Revoke certificates
|
|
- Robust implementation of all ACME challenges
|
|
- HTTP (http-01)
|
|
- TLS with Server Name Indication (tls-sni-01)
|
|
- DNS (dns-01)
|
|
- SAN certificate support
|
|
- Comes with multiple optional [DNS providers](https://github.com/xenolf/lego/tree/master/providers/dns)
|
|
- [Custom challenge solvers](https://github.com/xenolf/lego/wiki/Writing-a-Challenge-Solver)
|
|
- Certificate bundling
|
|
- OCSP helper function
|
|
|
|
Please keep in mind that CLI switches and APIs are still subject to change.
|
|
|
|
When using the standard `--path` option, all certificates and account configurations are saved to a folder *.lego* in the current working directory.
|
|
|
|
#### Sudo
|
|
The CLI does not require root permissions but needs to bind to port 80 and 443 for certain challenges.
|
|
To run the CLI without sudo, you have four options:
|
|
|
|
- Use setcap 'cap_net_bind_service=+ep' /path/to/program
|
|
- Pass the `--http` or/and the `--tls` option and specify a custom port to bind to. In this case you have to forward port 80/443 to these custom ports (see [Port Usage](#port-usage)).
|
|
- Pass the `--webroot` option and specify the path to your webroot folder. In this case the challenge will be written in a file in `.well-known/acme-challenge/` inside your webroot.
|
|
- Pass the `--dns` option and specify a DNS provider.
|
|
|
|
#### Port Usage
|
|
By default lego assumes it is able to bind to ports 80 and 443 to solve challenges.
|
|
If this is not possible in your environment, you can use the `--http` and `--tls` options to instruct
|
|
lego to listen on that interface:port for any incoming challenges.
|
|
|
|
If you are using this option, make sure you proxy all of the following traffic to these ports.
|
|
|
|
HTTP Port:
|
|
- All plaintext HTTP requests to port 80 which begin with a request path of `/.well-known/acme-challenge/` for the HTTP challenge.
|
|
|
|
TLS Port:
|
|
- All TLS handshakes on port 443 for the TLS-SNI challenge.
|
|
|
|
This traffic redirection is only needed as long as lego solves challenges. As soon as you have received your certificates you can deactivate the forwarding.
|
|
|
|
#### Usage
|
|
|
|
```
|
|
Let's Encrypt client written in Go
|
|
|
|
Usage:
|
|
lego [command]
|
|
|
|
Available Commands:
|
|
dnshelp Shows additional help for the --dns global option
|
|
renew Renew a certificate
|
|
revoke Revoke a certificate
|
|
run Register an account, then create and install a certificate
|
|
version Prints current version of lego
|
|
|
|
Flags:
|
|
-a, --accept-tos By setting this flag to true you indicate that you accept the current Let's Encrypt terms of service.
|
|
--dns string Solve a DNS challenge using the specified provider. Disables all other challenges. Run 'lego dnshelp' for help on usage.
|
|
-d, --domains value Add domains to the process (default [])
|
|
-m, --email string Email used for registration and recovery contact.
|
|
-x, --exclude value Explicitly disallow solvers by name from being used. Solvers: "http-01", "tls-sni-01". (default [])
|
|
-h, --help help for lego
|
|
--http string Set the port and interface to use for HTTP based challenges to listen on. Supported: interface:port or :port
|
|
-k, --key-type string Key type to use for private keys. Supported: rsa2048, rsa4096, rsa8192, ec256, ec384 (default "rsa2048")
|
|
--path string Directory to use for storing the data (default "{$CWD}/.lego")
|
|
-s, --server string CA hostname (and optionally :port). The server certificate must be trusted in order to avoid further modifications to the client. (default "https://acme-v01.api.letsencrypt.org/directory")
|
|
--tls string Set the port and interface to use for TLS based challenges to listen on. Supported: interface:port or :port
|
|
--webroot string Set the webroot folder to use for HTTP based challenges to write directly in a file in .well-known/acme-challenge
|
|
|
|
Use "lego [command] --help" for more information about a command.
|
|
```
|
|
|
|
For further help on a command:
|
|
```
|
|
$ lego renew --help
|
|
Renew a certificate
|
|
|
|
Usage:
|
|
lego renew [flags]
|
|
|
|
Flags:
|
|
--days int The number of days left on a certificate to renew it.
|
|
--no-bundle Do not create a certificate bundle by adding the issuers certificate to the new certificate.
|
|
--resuse-key Used to indicate you want to reuse your current private key for the new certificate.
|
|
|
|
...
|
|
```
|
|
|
|
##### CLI Example
|
|
|
|
Assumes the `lego` binary has permission to bind to ports 80 and 443. You can get a pre-built binary from the [releases](https://github.com/xenolf/lego/releases) page.
|
|
If your environment does not allow you to bind to these ports, please read [Port Usage](#port-usage).
|
|
|
|
Obtain a certificate:
|
|
|
|
```bash
|
|
$ lego run --email="foo@bar.com" --domains="example.com"
|
|
```
|
|
|
|
(Find your certificate in the `.lego` folder of current working directory.)
|
|
|
|
To renew the certificate:
|
|
|
|
```bash
|
|
$ lego renew --email="foo@bar.com" --domains="example.com"
|
|
```
|
|
|
|
Obtain a certificate using the DNS challenge and AWS Route 53:
|
|
|
|
```bash
|
|
$ AWS_REGION=us-east-1 AWS_ACCESS_KEY_ID=my_id AWS_SECRET_ACCESS_KEY=my_key lego run --email="foo@bar.com" --domains="example.com" --dns="route53"
|
|
```
|
|
|
|
Note that `--dns=foo` implies `--exclude=http-01` and `--exclude=tls-sni-01`. lego will not attempt other challenges if you've told it to use DNS instead.
|
|
|
|
lego defaults to communicating with the production Let's Encrypt ACME server. If you'd like to test something without issuing real certificates, consider using the staging endpoint instead:
|
|
|
|
```bash
|
|
$ lego --server=https://acme-staging.api.letsencrypt.org/directory …
|
|
```
|
|
|
|
#### DNS Challenge API Details
|
|
|
|
##### AWS Route 53
|
|
|
|
The following AWS IAM policy document describes the permissions required for lego to complete the DNS challenge.
|
|
Replace `<INSERT_YOUR_HOSTED_ZONE_ID_HERE>` with the Route 53 zone ID of the domain you are authorizing.
|
|
|
|
```json
|
|
{
|
|
"Version": "2012-10-17",
|
|
"Statement": [
|
|
{
|
|
"Effect": "Allow",
|
|
"Action": [
|
|
"route53:GetChange",
|
|
"route53:ListHostedZonesByName"
|
|
],
|
|
"Resource": [
|
|
"*"
|
|
]
|
|
},
|
|
{
|
|
"Effect": "Allow",
|
|
"Action": [
|
|
"route53:ChangeResourceRecordSets"
|
|
],
|
|
"Resource": [
|
|
"arn:aws:route53:::hostedzone/<INSERT_YOUR_HOSTED_ZONE_ID_HERE>"
|
|
]
|
|
}
|
|
]
|
|
}
|
|
```
|
|
|
|
#### ACME Library Usage
|
|
|
|
A valid, but bare-bones example use of the acme package:
|
|
|
|
```go
|
|
// You'll need a user or account type that implements acme.User
|
|
type MyUser struct {
|
|
Email string
|
|
Registration *acme.RegistrationResource
|
|
key crypto.PrivateKey
|
|
}
|
|
func (u MyUser) GetEmail() string {
|
|
return u.Email
|
|
}
|
|
func (u MyUser) GetRegistration() *acme.RegistrationResource {
|
|
return u.Registration
|
|
}
|
|
func (u MyUser) GetPrivateKey() crypto.PrivateKey {
|
|
return u.key
|
|
}
|
|
|
|
// Create a user. New accounts need an email and private key to start.
|
|
const rsaKeySize = 2048
|
|
privateKey, err := rsa.GenerateKey(rand.Reader, rsaKeySize)
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
myUser := MyUser{
|
|
Email: "you@yours.com",
|
|
key: privateKey,
|
|
}
|
|
|
|
// A client facilitates communication with the CA server. This CA URL is
|
|
// configured for a local dev instance of Boulder running in Docker in a VM.
|
|
client, err := acme.NewClient("http://192.168.99.100:4000", &myUser, acme.RSA2048)
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
|
|
// We specify an http port of 5002 and an tls port of 5001 on all interfaces
|
|
// because we aren't running as root and can't bind a listener to port 80 and 443
|
|
// (used later when we attempt to pass challenges). Keep in mind that we still
|
|
// need to proxy challenge traffic to port 5002 and 5001.
|
|
client.SetHTTPAddress(":5002")
|
|
client.SetTLSAddress(":5001")
|
|
|
|
// New users will need to register
|
|
reg, err := client.Register()
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
myUser.Registration = reg
|
|
|
|
// SAVE THE USER.
|
|
|
|
// The client has a URL to the current Let's Encrypt Subscriber
|
|
// Agreement. The user will need to agree to it.
|
|
err = client.AgreeToTOS()
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
|
|
// The acme library takes care of completing the challenges to obtain the certificate(s).
|
|
// The domains must resolve to this machine or you have to use the DNS challenge.
|
|
bundle := false
|
|
certificates, failures := client.ObtainCertificate([]string{"mydomain.com"}, bundle, nil)
|
|
if len(failures) > 0 {
|
|
log.Fatal(failures)
|
|
}
|
|
|
|
// Each certificate comes back with the cert bytes, the bytes of the client's
|
|
// private key, and a certificate URL. SAVE THESE TO DISK.
|
|
fmt.Printf("%#v\n", certificates)
|
|
|
|
// ... all done.
|
|
```
|