2019-05-10 01:45:57 +00:00
|
|
|
# Provisioners
|
|
|
|
|
|
|
|
|
|
Provisioners are people or code that are registered with the CA and authorized
|
|
|
|
|
to issue "provisioning tokens". Provisioning tokens are single-use tokens that
|
|
|
|
|
can be used to authenticate with the CA and get a certificate.
|
|
|
|
|
|
|
|
|
|
## JWK
|
|
|
|
|
|
2019-06-11 15:28:43 +00:00
|
|
|
JWK is the default provisioner type. It uses public-key cryptography to sign and
|
2019-05-10 01:45:57 +00:00
|
|
|
validate a JSON Web Token (JWT).
|
|
|
|
|
|
|
|
|
|
The [step](https://github.com/smallstep/cli) CLI tool will create a JWK
|
|
|
|
|
provisioner when `step ca init` is used, and it also contains commands to add
|
|
|
|
|
(`step ca provisioner add`) and remove (`step ca provisioner remove`) JWK
|
|
|
|
|
provisioners.
|
|
|
|
|
|
|
|
|
|
In the ca.json configuration file, a complete JWK provisioner example looks like:
|
|
|
|
|
|
|
|
|
|
```json
|
|
|
|
|
{
|
|
|
|
|
"type": "JWK",
|
|
|
|
|
"name": "you@smallstep.com",
|
|
|
|
|
"key": {
|
|
|
|
|
"use": "sig",
|
|
|
|
|
"kty": "EC",
|
|
|
|
|
"kid": "NPM_9Gz_omTqchS6Xx9Yfvs-EuxkYo6VAk4sL7gyyM4",
|
|
|
|
|
"crv": "P-256",
|
|
|
|
|
"alg": "ES256",
|
|
|
|
|
"x": "bBI5AkO9lwvDuWGfOr0F6ttXC-ZRzJo8kKn5wTzRJXI",
|
|
|
|
|
"y": "rcfaqE-EEZgs34Q9SSH3f9Ua5a8dKopXNfEzDD8KRlU"
|
|
|
|
|
},
|
|
|
|
|
"encryptedKey": "eyJhbGciOiJQQkVTMi1IUzI1NitBMTI4S1ciLCJjdHkiOiJqd2sranNvbiIsImVuYyI6IkEyNTZHQ00iLCJwMmMiOjEwMDAwMCwicDJzIjoiTlV6MjlEb3hKMVdOaFI3dUNjaGdYZyJ9.YN7xhz6RAbz_9bcuXoymBOj8bOg23ETAdmSCRyHpxGekkV0q3STYYg.vo1oBnZsZjgRu5Ln.Xop8AvZ74h_im2jxeaq-hYYWnaK_eF7MGr4xcZGodMUxp-hGPqS85oWkyprkQLYt1-jXTURfpejtmPeB4-sxgj7OFxMYYus84BdkG9BZgSBmMN9SqZItOv4pqg_NwQA0bv9g9A_e-N6QUFanxuYQsEPX_-IwWBDbNKyN9bXbpEQa0FKNVsTvFahGzOxQngXipi265VADkh8MJLjYerplKIbNeOJJbLd9CbS9fceLvQUNr3ACGgAejSaWmeNUVqbho1lY4882iS8QVx1VzjluTXlAMdSUUDHArHEihz008kCyF0YfvNdGebyEDLvTmF6KkhqMpsWn3zASYBidc9k._ch9BtvRRhcLD838itIQlw",
|
|
|
|
|
"claims": {
|
|
|
|
|
"minTLSCertDuration": "5m",
|
|
|
|
|
"maxTLSCertDuration": "24h",
|
|
|
|
|
"defaultTLSCertDuration": "24h",
|
|
|
|
|
"disableRenewal": false
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
* `type` (mandatory): for a JWK provisioner it must be `JWK`, this field is case
|
|
|
|
|
insensitive.
|
|
|
|
|
|
|
|
|
|
* `name` (mandatory): identifies the provisioner, a good practice is to
|
|
|
|
|
use an email address or a descriptive string that allows the identification of
|
|
|
|
|
the owner, but it can be any non-empty string.
|
|
|
|
|
|
|
|
|
|
* `key` (mandatory): is the JWK (JSON Web Key) representation of a public key
|
|
|
|
|
used to validate a signed token.
|
|
|
|
|
|
|
|
|
|
* `encryptedKey` (recommended): is the encrypted private key used to sign a
|
|
|
|
|
token. It's a JWE compact string containing the JWK representation of the
|
|
|
|
|
private key.
|
|
|
|
|
|
|
|
|
|
We can use [step](https://github.com/smallstep/cli) to see the private key
|
|
|
|
|
encrypted with the password `asdf`:
|
2019-06-11 15:28:43 +00:00
|
|
|
|
2019-05-10 01:45:57 +00:00
|
|
|
```sh
|
|
|
|
|
$ echo ey...lw | step crypto jwe decrypt | jq
|
|
|
|
|
Please enter the password to decrypt the content encryption key:
|
|
|
|
|
{
|
|
|
|
|
"use": "sig",
|
|
|
|
|
"kty": "EC",
|
|
|
|
|
"kid": "NPM_9Gz_omTqchS6Xx9Yfvs-EuxkYo6VAk4sL7gyyM4",
|
|
|
|
|
"crv": "P-256",
|
|
|
|
|
"alg": "ES256",
|
|
|
|
|
"x": "bBI5AkO9lwvDuWGfOr0F6ttXC-ZRzJo8kKn5wTzRJXI",
|
|
|
|
|
"y": "rcfaqE-EEZgs34Q9SSH3f9Ua5a8dKopXNfEzDD8KRlU",
|
|
|
|
|
"d": "rsjCCM_2FQ-uk7nywBEQHl84oaPo4mTpYDgXAu63igE"
|
|
|
|
|
}
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
If the ca.json does not contain the encryptedKey, the private key must be
|
|
|
|
|
provided using the `--key` flag of the `step ca token` to be able to sign the
|
|
|
|
|
token.
|
|
|
|
|
|
|
|
|
|
* `claims` (optional): overwrites the default claims set in the authority.
|
|
|
|
|
You can set one or more of the following claims:
|
|
|
|
|
|
|
|
|
|
* `minTLSCertDuration`: do not allow certificates with a duration less than
|
|
|
|
|
this value.
|
|
|
|
|
|
|
|
|
|
* `maxTLSCertDuration`: do not allow certificates with a duration greater than
|
|
|
|
|
this value.
|
|
|
|
|
|
|
|
|
|
* `defaultTLSCertDuration`: if no certificate validity period is specified,
|
|
|
|
|
use this value.
|
|
|
|
|
|
|
|
|
|
* `disableIssuedAtCheck`: disable a check verifying that provisioning tokens
|
|
|
|
|
must be issued after the CA has booted. This claim is one prevention against
|
|
|
|
|
token reuse. The default value is `false`. Do not change this unless you
|
|
|
|
|
know what you are doing.
|
|
|
|
|
|
|
|
|
|
## OIDC
|
|
|
|
|
|
|
|
|
|
An OIDC provisioner allows a user to get a certificate after authenticating
|
|
|
|
|
himself with an OAuth OpenID Connect identity provider. The ID token provided
|
|
|
|
|
will be used on the CA authentication, and by default, the certificate will only
|
|
|
|
|
have the user's email as a Subject Alternative Name (SAN) Extension.
|
|
|
|
|
|
|
|
|
|
One of the most common providers and the one we'll use in the following example
|
|
|
|
|
is G-Suite.
|
|
|
|
|
|
|
|
|
|
```json
|
|
|
|
|
{
|
|
|
|
|
"type": "OIDC",
|
|
|
|
|
"name": "Google",
|
|
|
|
|
"clientID": "1087160488420-8qt7bavg3qesdhs6it824mhnfgcfe8il.apps.googleusercontent.com",
|
|
|
|
|
"clientSecret": "udTrOT3gzrO7W9fDPgZQLfYJ",
|
|
|
|
|
"configurationEndpoint": "https://accounts.google.com/.well-known/openid-configuration",
|
|
|
|
|
"admins": ["you@smallstep.com"],
|
|
|
|
|
"domains": ["smallstep.com"],
|
2019-09-19 17:20:41 +00:00
|
|
|
"listenAddress": ":10000",
|
2019-05-10 01:45:57 +00:00
|
|
|
"claims": {
|
|
|
|
|
"maxTLSCertDuration": "8h",
|
|
|
|
|
"defaultTLSCertDuration": "2h",
|
|
|
|
|
"disableRenewal": true
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
* `type` (mandatory): indicates the provisioner type and must be `OIDC`.
|
|
|
|
|
|
|
|
|
|
* `name` (mandatory): a string used to identify the provider when the CLI is
|
|
|
|
|
used.
|
|
|
|
|
|
|
|
|
|
* `clientID` (mandatory): the client id provided by the identity provider used
|
|
|
|
|
to initialize the authentication flow.
|
|
|
|
|
|
|
|
|
|
* `clientSecret` (mandatory): the client secret provided by the identity
|
|
|
|
|
provider used to get the id token. Some identity providers might use an empty
|
|
|
|
|
string as a secret.
|
|
|
|
|
|
2019-10-01 09:20:03 +00:00
|
|
|
* `configurationEndpoint` (mandatory): is the HTTP address used by the CA to get
|
2019-05-10 01:45:57 +00:00
|
|
|
the OpenID Connect configuration and public keys used to validate the tokens.
|
|
|
|
|
|
|
|
|
|
* `admins` (optional): is the list of emails that will be able to get
|
|
|
|
|
certificates with custom SANs. If a user is not an admin, it will only be able
|
|
|
|
|
to get a certificate with its email in it.
|
|
|
|
|
|
|
|
|
|
* `domains` (optional): is the list of domains valid. If provided only the
|
|
|
|
|
emails with the provided domains will be able to authenticate.
|
|
|
|
|
|
2019-09-19 17:20:41 +00:00
|
|
|
* `listenAddress` (optional): is the loopback address (`:port` or `host:port`)
|
|
|
|
|
where the authorization server will redirect to complete the authorization
|
|
|
|
|
flow. If it's not defined `step` will use `127.0.0.1` with a random port. This
|
|
|
|
|
configuration is only required if the authorization server doesn't allow any
|
|
|
|
|
port to be specified at the time of the request for loopback IP redirect URIs.
|
|
|
|
|
|
2019-05-10 01:45:57 +00:00
|
|
|
* `claims` (optional): overwrites the default claims set in the authority, see
|
|
|
|
|
the [JWK](#jwk) section for all the options.
|
|
|
|
|
|
|
|
|
|
## Provisioners for Cloud Identities
|
|
|
|
|
|
|
|
|
|
[Step certificates](https://github.com/smallstep/certificates) can grant
|
|
|
|
|
certificates to code running in a machine without any other authentication than
|
|
|
|
|
the one provided by the cloud. Usually, this is implemented with some kind of
|
|
|
|
|
signed document, but the information contained on them might not be enough to
|
|
|
|
|
generate a certificate. Due to this limitation, the cloud identities use by
|
|
|
|
|
default a trust model called Trust On First Use (TOFU).
|
|
|
|
|
|
|
|
|
|
The Trust On First Use model allows the use of more permissive CSRs that can
|
|
|
|
|
have custom SANs that cannot be validated. But it comes with the limitation that
|
|
|
|
|
you can only grant a certificate once. After this first grant, the same machine
|
|
|
|
|
will need to renew the certificate using mTLS, and the CA will block any other
|
|
|
|
|
attempt to grant a certificate to that instance.
|
|
|
|
|
|
|
|
|
|
### AWS
|
|
|
|
|
|
|
|
|
|
The AWS provisioner allows granting a certificate to an Amazon EC2 instance
|
|
|
|
|
using the [Instance Identity Documents](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-identity-documents.html)
|
|
|
|
|
|
|
|
|
|
The [step](https://github.com/smallstep/cli) CLI will generate a custom JWT
|
|
|
|
|
token containing the instance identity document and its signature and the CA
|
|
|
|
|
will grant a certificate after validating it.
|
|
|
|
|
|
|
|
|
|
In the ca.json, an AWS provisioner looks like:
|
|
|
|
|
|
|
|
|
|
```json
|
|
|
|
|
{
|
|
|
|
|
"type": "AWS",
|
|
|
|
|
"name": "Amazon Web Services",
|
|
|
|
|
"accounts": ["1234567890"],
|
|
|
|
|
"disableCustomSANs": false,
|
|
|
|
|
"disableTrustOnFirstUse": false,
|
2019-06-05 17:50:08 +00:00
|
|
|
"instanceAge": "1h",
|
2019-05-10 01:45:57 +00:00
|
|
|
"claims": {
|
|
|
|
|
"maxTLSCertDuration": "2160h",
|
|
|
|
|
"defaultTLSCertDuration": "2160h"
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
* `type` (mandatory): indicates the provisioner type and must be `AWS`.
|
|
|
|
|
|
|
|
|
|
* `name` (mandatory): a string used to identify the provider when the CLI is
|
|
|
|
|
used.
|
|
|
|
|
|
|
|
|
|
* `accounts` (optional): the list of AWS account numbers that are allowed to use
|
|
|
|
|
this provisioner. If none is specified, all AWS accounts will be valid.
|
|
|
|
|
|
|
|
|
|
* `disableCustomSANs` (optional): by default custom SANs are valid, but if this
|
|
|
|
|
option is set to true only the SANs available in the instance identity
|
|
|
|
|
document will be valid, these are the private IP and the DNS
|
|
|
|
|
`ip-<private-ip>.<region>.compute.internal`.
|
|
|
|
|
|
|
|
|
|
* `disableTrustOnFirstUse` (optional): by default only one certificate will be
|
|
|
|
|
granted per instance, but if the option is set to true this limit is not set
|
|
|
|
|
and different tokens can be used to get different certificates.
|
|
|
|
|
|
2019-06-05 17:50:08 +00:00
|
|
|
* `instanceAge` (optional): the maximum age of an instance to grant a
|
|
|
|
|
certificate. The instance age is a string using the duration format.
|
|
|
|
|
|
2019-05-10 01:45:57 +00:00
|
|
|
* `claims` (optional): overwrites the default claims set in the authority, see
|
|
|
|
|
the [JWK](#jwk) section for all the options.
|
|
|
|
|
|
|
|
|
|
### GCP
|
|
|
|
|
|
|
|
|
|
The GCP provisioner grants certificates to Google Compute Engine instance using
|
|
|
|
|
its [identity](https://cloud.google.com/compute/docs/instances/verifying-instance-identity)
|
|
|
|
|
token. The CA will validate the JWT and grant a certificate.
|
|
|
|
|
|
|
|
|
|
In the ca.json, a GCP provisioner looks like:
|
|
|
|
|
|
|
|
|
|
```json
|
|
|
|
|
{
|
|
|
|
|
"type": "GCP",
|
|
|
|
|
"name": "Google Cloud",
|
|
|
|
|
"serviceAccounts": ["1234567890"],
|
2019-06-05 17:50:08 +00:00
|
|
|
"projectIDs": ["project-id"],
|
2019-05-10 01:45:57 +00:00
|
|
|
"disableCustomSANs": false,
|
|
|
|
|
"disableTrustOnFirstUse": false,
|
2019-06-05 17:50:08 +00:00
|
|
|
"instanceAge": "1h",
|
2019-05-10 01:45:57 +00:00
|
|
|
"claims": {
|
|
|
|
|
"maxTLSCertDuration": "2160h",
|
|
|
|
|
"defaultTLSCertDuration": "2160h"
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
* `type` (mandatory): indicates the provisioner type and must be `GCP`.
|
|
|
|
|
|
|
|
|
|
* `name` (mandatory): a string used to identify the provider when the CLI is
|
|
|
|
|
used.
|
|
|
|
|
|
|
|
|
|
* `serviceAccounts` (optional): the list of service account numbers that are
|
|
|
|
|
allowed to use this provisioner. If none is specified, all service accounts
|
|
|
|
|
will be valid.
|
|
|
|
|
|
2019-06-05 17:50:08 +00:00
|
|
|
* `projectIDs` (optional): the list of project identifiers that are allowed to
|
|
|
|
|
use this provisioner. If non is specified all project will be valid.
|
|
|
|
|
|
2019-05-10 01:45:57 +00:00
|
|
|
* `disableCustomSANs` (optional): by default custom SANs are valid, but if this
|
|
|
|
|
option is set to true only the SANs available in the instance identity
|
|
|
|
|
document will be valid, these are the DNS
|
|
|
|
|
`<instance-name>.c.<project-id>.internal` and
|
|
|
|
|
`<instance-name>.<zone>.c.<project-id>.internal`
|
|
|
|
|
|
|
|
|
|
* `disableTrustOnFirstUse` (optional): by default only one certificate will be
|
|
|
|
|
granted per instance, but if the option is set to true this limit is not set
|
|
|
|
|
and different tokens can be used to get different certificates.
|
|
|
|
|
|
2019-06-05 17:50:08 +00:00
|
|
|
* `instanceAge` (optional): the maximum age of an instance to grant a
|
|
|
|
|
certificate. The instance age is a string using the duration format.
|
|
|
|
|
|
2019-05-10 01:45:57 +00:00
|
|
|
* `claims` (optional): overwrites the default claims set in the authority, see
|
|
|
|
|
the [JWK](#jwk) section for all the options.
|
|
|
|
|
|
|
|
|
|
### Azure
|
|
|
|
|
|
|
|
|
|
The Azure provisioner grants certificates to Microsoft Azure instances using
|
|
|
|
|
the [managed identities tokens](https://docs.microsoft.com/en-us/azure/active-directory/managed-identities-azure-resources/how-to-use-vm-token).
|
|
|
|
|
The CA will validate the JWT and grant a certificate.
|
|
|
|
|
|
|
|
|
|
In the ca.json, an Azure provisioner looks like:
|
|
|
|
|
|
|
|
|
|
```json
|
|
|
|
|
{
|
|
|
|
|
"type": "Azure",
|
|
|
|
|
"name": "Microsoft Azure",
|
|
|
|
|
"tenantId": "b17c217c-84db-43f0-babd-e06a71083cda",
|
|
|
|
|
"resourceGroups": ["backend", "accounting"],
|
|
|
|
|
"audience": "https://management.azure.com/",
|
|
|
|
|
"disableCustomSANs": false,
|
|
|
|
|
"disableTrustOnFirstUse": false,
|
|
|
|
|
"claims": {
|
|
|
|
|
"maxTLSCertDuration": "2160h",
|
|
|
|
|
"defaultTLSCertDuration": "2160h"
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
* `type` (mandatory): indicates the provisioner type and must be `Azure`.
|
|
|
|
|
|
|
|
|
|
* `name` (mandatory): a string used to identify the provider when the CLI is
|
|
|
|
|
used.
|
|
|
|
|
|
|
|
|
|
* `tenantId` (mandatory): the Azure account tenant id for this provisioner. This
|
|
|
|
|
id is the Directory ID available in the Azure Active Directory properties.
|
|
|
|
|
|
|
|
|
|
* `audience` (optional): defaults to `https://management.azure.com/` but it can
|
|
|
|
|
be changed if necessary.
|
|
|
|
|
|
|
|
|
|
* `resourceGroups` (optional): the list of resource group names that are allowed
|
|
|
|
|
to use this provisioner. If none is specified, all resource groups will be
|
|
|
|
|
valid.
|
|
|
|
|
|
|
|
|
|
* `disableCustomSANs` (optional): by default custom SANs are valid, but if this
|
|
|
|
|
option is set to true only the SANs available in the token will be valid, in
|
|
|
|
|
Azure only the virtual machine name is available.
|
|
|
|
|
|
|
|
|
|
* `disableTrustOnFirstUse` (optional): by default only one certificate will be
|
|
|
|
|
granted per instance, but if the option is set to true this limit is not set
|
|
|
|
|
and different tokens can be used to get different certificates.
|
|
|
|
|
|
|
|
|
|
* `claims` (optional): overwrites the default claims set in the authority, see
|
|
|
|
|
the [JWK](#jwk) section for all the options.
|
