hedgedoc/docs/guides/auth/saml-keycloak.md

How to setup CodiMD SAML with Keycloak

Configuring Keycloak

Get the public certificate

1. Select the Realm you want to use for your CodiMD SAML
2. Select "Realm Settings" in left sidebar
3. Select the "Keys" tab
4. Click the button "Certificate" at RS256 algorithm
5. Copy this key and save it to the file specified in saml.idpCert property of the CodiMD configuration or CMD_SAML_IDPCERT environment variable

Create a new client

1. Select "Client" in left sidebar
2. Click on the "Create" button
3. Set a Client ID and specify this in saml.issuer property of the CodiMD configuration or CMD_SAML_ISSUER environment variable
4. Select SAML as Client Protocol
5. Set Client SAML Endpoint to https://codimd.example.com/auth/saml (replace https://codimd.example.com with the base URL of your CodiMD installation)
6. Leave "Client Signature Required" enabled
7. Set Root URL to https://codimd.example.com (replace it here also with the base URL of your CodiMD installation)
8. Set Valid Redirect URIs to https://codimd.example.com/auth/saml/callback (you should also define all other domains of your CodiMD installtion with the suffix /auth/saml/callback)
9. Set Base URL to /
10. (optional) You can set which Name ID Format should be used

Configure CodiMD

Config file

You have to put the following block inside your config.json:

"saml": {
  "issuer": "codimd", // Change to the "Client ID" specified in the Keycloak Client
  "identifierFormat": "urn:oasis:names:tc:SAML:1.1:nameid-format:unspecified",
  "idpSsoUrl": "https://keycloak.example.org/auth/realms/test/protocol/saml", // replace keycloak.example.org with the url of your keycloak server
  "idpCert": "/path/to/the/cert.pem",
  "clientCert": "/path/to/the/key.pem" // this one is optional, see below
}

Environment Variables

• CMD_SAML_IDPSSOURL: https://keycloak.example.org/auth/realms/test/protocol/saml (replace keycloak.example.org with the url of your keycloak server)
• CMD_SAML_IDPCERT: /path/to/the/cert.pem
• (optional, see below) CMD_SAML_CLIENTCERT: /path/to/the/key.pem
• CMD_SAML_ISSUER: codimd (Change to the "Client ID" specified in the Keycloak Client)
• CMD_SAML_IDENTIFIERFORMAT: urn:oasis:names:tc:SAML:1.1:nameid-format:unspecified

Client certificate (optional)

If you want keycloak to be able to verify CodiMD, you hava to create a client certificate. There are two options for this:

Create Private Keys for Signing

1. Generate the private key and certificate with the following commands:

openssl genrsa -out priv.pem 2048
openssl req -new -x509 -key priv.pem -out cert.pem

execute the following steps in keycloak

2. Select "Client" in left sidebar
3. Go to your CodiMD-Client
4. Select the "SAML Keys" tab
5. Click on "Import"
6. Select Certificate PEM as "Archive Format"
7. Now upload the generated cert.pem (in this case named cert.pem)
8. Click on "Import"
9. Move or copy this key (in this case named key.pem) and save it to the file specified in saml.clientCert property of the CodiMD configuration or in the enviroment-variable CMD_SAML_CLIENTCERT

Convert Private Certificate generated by KeyCloak

Instead if generating you own certificate, you can also use the one generated by keycloak.

1. Select "Client" in left sidebar

2. Go to your CodiMD-Client

3. Select the "SAML Keys" tab

4. Now click on "Export"

5. Here you can select the output format, choose PKCS12. You also have to set a password. Choose your own.

6. Click on "Download" and save the file somewhere on you computer

7. You now have to extract the private Key. You can do this with the following command. WHen asked, enter your password.

openssl pkcs12 -in keystore.p12 -out key.pem -nocerts -nodes

8. Move or copy this key (in this case named key.pem) and save it to the file specified in saml.idpCert property of the CodiMD configuration or in the enviroment-variable CMD_SAML_CLIENTCERT

Use Persistent Identifiers

Instead of using the username as the owner-key in the CodiMD database, you can also use a persistent identifier. This allows to change the username, without them loosing access to their notes.

1. Go to the CodiMD-Client in keycloak. Now enable the option "Force Name ID Format" and select "persistent" as the "Name ID Format".
2. For codimd to be able to use the username and email configured in keycloak, you have to create the following SAML protocol mappers: 2.1. Create a mapper with the type User Property. Set the Name, Property and SAML Attribute Name to username. Now you can specify a friendly name (for example Username) 2.2 Create a mapper with the type User Property. Set the Name, Property and SAML Attribute Name to email. Now you can specify a friendly name (for example E-Mail)

The configured mappers should look like this:

3. You now have to add the following block to the saml-definition inside your config.json:

"attribute": {
      "username": "username"
      "email": "email",
}

It you configure CodiMD with enviroment variables, these are the ones you have to set:

CMD_SAML_ATTRIBUTE_USERNAME=username
CMD_SAML_ATTRIBUTE_EMAIL=email