TLS Configuration

Connections between Dgraph database and its clients can be secured using TLS. In addition, Dgraph can now secure gRPC communications between Dgraph Alpha and Dgraph Zero server nodes using mutual TLS (mTLS). Dgraph can now also secure communications over the Dgraph Zero gRPC-external-private port used by Dgraph’s Live Loader and Bulk Loader clients. To learn more about the HTTP and gRPC ports used by Dgraph Alpha and Dgraph Zero, see Ports Usage. Password-protected private keys are not supported.

To further improve TLS security, only TLS v1.2 cypher suites that use 128-bit or greater RSA or AES encryption are supported.

Dgraph Certificate Management Tool

The dgraph cert program creates and manages CA-signed certificates and private keys using a generated Dgraph Root CA. There are three types of certificate/key pairs:

1. Root CA certificate/key pair: This is used to sign and verify node and client certificates. If the root CA certificate is changed then you must regenerate all certificates, and this certificate must be accessible to the Alpha nodes.
2. Node certificate/key pair: This is shared by the Dgraph Alpha nodes and used for accepting TLS connections.
3. Client certificate/key pair: This is used by the clients (like live loader and Ratel) to communicate with Dgraph Alpha server nodes where client authentication with mTLS is required.

# To see the available flags.
$ dgraph cert --help

# Create Dgraph Root CA, used to sign all other certificates.
$ dgraph cert

# Create node certificate and private key
$ dgraph cert -n localhost

# Create client certificate and private key for mTLS (mutual TLS)
$ dgraph cert -c dgraphuser

# Combine all in one command
$ dgraph cert -n localhost -c dgraphuser

# List all your certificates and keys
$ dgraph cert ls

The default location where the cert command stores certificates (and keys) is tls under the Dgraph working directory. The default directory path can be overridden using the --dir option. For example:

$ dgraph cert --dir ~/mycerts

File naming conventions

The following file naming conventions are used by Dgraph for proper TLS setup.

For client authentication, each client must have their own certificate and key. These are then used to connect to the Dgraph server nodes.

The node certificate node.crt can support multiple node names using multiple host names and/or IP address. Just separate the names with commas when generating the certificate.

$ dgraph cert -n localhost,104.25.165.23,dgraph.io,2400:cb00:2048:1::6819:a417

Certificate inspection

The command dgraph cert ls lists all certificates and keys in the --dir directory (default dgraph-tls), along with details to inspect and validate cert/key pairs.

Example of command output:

-rw-r--r-- ca.crt - Dgraph Root CA certificate
        Issuer: Dgraph Labs, Inc.
           S/N: 043c4d8fdd347f06
    Expiration: 02 Apr 29 16:56 UTC
SHA-256 Digest: 4A2B0F0F 716BF5B6 C603E01A 6229D681 0B2AFDC5 CADF5A0D 17D59299 116119E5

-r-------- ca.key - Dgraph Root CA key
SHA-256 Digest: 4A2B0F0F 716BF5B6 C603E01A 6229D681 0B2AFDC5 CADF5A0D 17D59299 116119E5

-rw-r--r-- client.admin.crt - Dgraph client certificate: admin
        Issuer: Dgraph Labs, Inc.
     CA Verify: PASSED
           S/N: 297e4cb4f97c71f9
    Expiration: 03 Apr 24 17:29 UTC
SHA-256 Digest: D23EFB61 DE03C735 EB07B318 DB70D471 D3FE8556 B15D084C 62675857 788DF26C

-rw------- client.admin.key - Dgraph Client key
SHA-256 Digest: D23EFB61 DE03C735 EB07B318 DB70D471 D3FE8556 B15D084C 62675857 788DF26C

-rw-r--r-- node.crt - Dgraph Node certificate
        Issuer: Dgraph Labs, Inc.
     CA Verify: PASSED
           S/N: 795ff0e0146fdb2d
    Expiration: 03 Apr 24 17:00 UTC
         Hosts: 104.25.165.23, 2400:cb00:2048:1::6819:a417, localhost, dgraph.io
SHA-256 Digest: 7E243ED5 3286AE71 B9B4E26C 5B2293DA D3E7F336 1B1AFFA7 885E8767 B1A84D28

-rw------- node.key - Dgraph Node key
SHA-256 Digest: 7E243ED5 3286AE71 B9B4E26C 5B2293DA D3E7F336 1B1AFFA7 885E8767 B1A84D28

Important points:

• The cert/key pairs should always have matching SHA-256 digests. Otherwise, the cert(s) must be regenerated. If the Root CA pair differ, all cert/key must be regenerated; the flag --force can help.
• All certificates must pass Dgraph CA verification.
• All key files should have the least access permissions, especially the ca.key, but be readable.
• Key files won’t be overwritten if they have limited access, even with --force.
• Node certificates are only valid for the hosts listed.
• Client certificates are only valid for the named client/user.

TLS options

Starting in release v21.03, pre-existing TLS configuration options have been replaced by the --tls superflag and its options. The following --tls configuration options are available for Dgraph Alpha and Dgraph Zero nodes:

• ca-cert <path> - Path and filename of the Dgraph Root CA (for example, ca.crt)
• server-cert <path> - Path and filename of the node certificate (for example, node.crt)
• server-key <path> - Path and filename of the node certificate private key (for example, node.key)
• use-system-ca - Include System CA with Dgraph Root CA.
• client-auth-type <string> - TLS client authentication used to validate client connections from external ports. To learn more, see Client Authentication Options.

You can configure Dgraph Live Loader with the following --tls options:

• ca-cert <path> - Dgraph root CA, such as ./tls/ca.crt
• use-system-ca - Include System CA with Dgraph Root CA.
• client-cert - User cert file provided by the client to Alpha
• client-key - User private key file provided by the client to Alpha
• server-name <string> - Server name, used for validating the server’s TLS host name.

Using TLS with only external ports encrypted

To encrypt communication between Dgraph server nodes and clients over external ports, you can configure certificates and run Dgraph Alpha and Dgraph Zero using the following commands:

Dgraph Alpha:

# First, create the root CA, Alpha node certificate and private keys, if not already created.
# Note that you must specify in node.crt the host name or IP addresses that clients use connect:
$ dgraph cert -n localhost,104.25.165.23,104.25.165.25,104.25.165.27
# Set up Dgraph Alpha nodes using the following default command (after generating certificates and private keys)
$ dgraph alpha --tls "ca-cert=/dgraph-tls/ca.crt; server-cert=/dgraph-tls/node.crt; server-key=/dgraph-tls/node.key"

Dgraph Zero:

# First, copy the root CA, node certificates and private keys used to set up Dgraph Alpha (above) to the Dgraph Zero node.
# Optionally, you can generate and use a separate Zero node certificate, where you specify the host name or IP addresses used by Live Loader and Bulk Loader to connect to Dgraph Zero.
# Next, set up Dgraph Zero nodes using the following default command:
$ dgraph zero --tls "ca-cert=/dgraph-tls/ca.crt; server-cert=/dgraph-tls/node.crt; server-key=/dgraph-tls/node.key"

You can then run Dgraph Live Loader on a Dgraph Alpha node using the following command:

# Now, connect to server using TLS
$ dgraph live --tls "ca-cert=./dgraph-tls/ca.crt; server-name=localhost" -s 21million.schema -f 21million.rdf.gz

Using TLS with internal and external ports encrypted

If you require client authentication (mutual TLS, or mTLS), you can configure certificates and run Dgraph Alpha and Dgraph Zero with settings that encrypt both internal ports (those used within the cluster) as well as external ports (those used by clients that connect to the cluster, including Bulk Loader and Live Loader).

The following example shows how to encrypt both internal and external ports:

Dgraph Alpha:

# First create the root CA, node certificates and private keys, if not already created.
# Note that you must specify the host name or IP address for other nodes that will share node.crt.
$ dgraph cert -n localhost,104.25.165.23,104.25.165.25,104.25.165.27
# Set up Dgraph Alpha nodes using the following default command (after generating certificates and private keys)
$ dgraph alpha
      --tls "ca-cert=/dgraph-tls/ca.crt; server-cert=/dgraph-tls/node.crt; server-key=/dgraph-tls/node.key;
internal-port=true; client-cert=/dgraph-tls/client.alpha1.crt; client-key=/dgraph-tls/client.alpha1.key"

Dgraph Zero:

# First, copy the certificates and private keys used to set up Dgraph Alpha (above) to the Dgraph Zero node.
# Next, set up Dgraph Zero nodes using the following default command:
$ dgraph zero
      --tls "ca-cert=/dgraph-tls/ca.crt; server-cert=/dgraph-tls/node.crt; server-key=/dgraph-tls/node.key; internal-port=true; client-cert=/dgraph-tls/client.zero1.crt; client-key=/dgraph-tls/client.zero1.key"

You can then run Dgraph Live Loader using the following:

# Now, connect to server using mTLS (mutual TLS)
$ dgraph live
   --tls "ca-cert=./tls/ca.crt; client-cert=./tls/client.dgraphuser.crt; client-key=./tls/client.dgraphuser.key; server-name=localhost; internal-port=true" \
   -s 21million.schema \
   -f 21million.rdf.gz

Client Authentication Options

The server will always request client authentication. There are four different values for the client-auth-type option that change the security policy of the client certificate.

REQUIREANDVERIFY is the most secure but also the most difficult to configure for clients. When using this value, the value of server-name is matched against the certificate SANs values and the connection host.

Using Ratel UI with Client authentication

Ratel UI (and any other JavaScript clients built on top of dgraph-js-http) connect to Dgraph servers via HTTP, when TLS is enabled servers begin to expect HTTPS requests only.

If you haven’t already created the CA certificate and the node certificate for alpha servers from the earlier instructions (see Dgraph Certificate Management Tool), the first step would be to generate these certificates, it can be done by the following command:

# Create rootCA and node certificates/keys
$ dgraph cert -n localhost

If Dgraph Alpha’s client-auth-type option is set to REQUEST or VERIFYIFGIVEN (default), then client certificate is not mandatory. The steps after generating CA/node certificate are as follows:

Step 1. Install Dgraph Root CA into System CA

Linux (Debian/Ubuntu)

# Copy the generated CA to the ca-certificates directory
$ cp /path/to/ca.crt /usr/local/share/ca-certificates/ca.crt
# Update the CA store
$ sudo update-ca-certificates`

Step 2. Install Dgraph Root CA into Web Browsers Trusted CA List

Firefox

• Choose Preferences -> Privacy & Security -> View Certificates -> Authorities
• Click on Import and import the ca.crt

Chrome

• Choose Settings -> Privacy and Security -> Security -> Manage Certificates -> Authorities
• Click on Import and import the ca.crt

Step 3. Point Ratel to the https:// endpoint of alpha server.

• Change the Dgraph Alpha server address to https:// instead of http://, for example https://localhost:8080.

For REQUIREANY and REQUIREANDVERIFY as client-auth-type option, you need to follow the steps above and you also need to install client certificate on your browser:

1. Generate a client certificate: dgraph cert -c laptopuser.

2. Convert it to a .p12 file:

   openssl pkcs12 -export \
      -out laptopuser.p12 \
      -in tls/client.laptopuser.crt \
      -inkey tls/client.laptopuser.key
   

   Use any password you like for export, it is used to encrypt the p12 file.

3. Import the client certificate to your browser. It can be done in Chrome as follows:

   • Choose Settings -> Privacy and Security -> Security -> Manage Certificates -> Your Certificates
   • Click on Import and import the laptopuser.p12.

Next time you use Ratel to connect to an alpha with Client authentication enabled the browser will prompt you for a client certificate to use. Select the client’s certificate you’ve imported in the step above and queries/mutations will succeed.

Using Curl with Client authentication

When TLS is enabled, curl requests to Dgraph will need some specific options to work. For instance (for changing draining mode):

curl --silent https://localhost:8080/admin/draining

If you are using curl with Client Authentication set to REQUIREANY or REQUIREANDVERIFY, you will need to provide the client certificate and private key. For instance (for an export request):

curl --silent --cacert ./tls/ca.crt --cert ./tls/client.dgraphuser.crt --key ./tls/client.dgraphuser.key https://localhost:8080/admin/draining

Refer to the curl documentation for further information on its TLS options.

Access Data Using a Client

Some examples of connecting via a Client when TLS is in use can be found below:

• dgraph4j
• dgraph-js
• dgo
• pydgraph

Troubleshooting Ratel’s Client authentication

If you are getting errors in Ratel when TLS is enabled, try opening your Dgraph Alpha URL as a web page.

Assuming you are running Dgraph on your local machine, opening https://localhost:8080/ in the browser should produce a message Dgraph browser is available for running separately using the dgraph-ratel binary.

In case you are getting a connection error, try not passing the client-auth-type flag when starting an alpha. If you are still getting an error, check that your hostname is correct and the port is open; then make sure that “Dgraph Root CA” certificate is installed and trusted correctly.

After that, if things work without passing client-auth-type but stop working when REQUIREANY and REQUIREANDVERIFY are set, make sure the .p12 file is installed correctly.