A secure CockroachDB cluster uses TLS for encrypted inter-node and client-node communication, which requires CA, node, and client certificates and keys. To create these certificates and keys, use the cockroach cert commands with the appropriate subcommands and flags, or use openssl commands.

Tip:
For details about when and how to change security certificates without restarting nodes, see Rotate Security Certificates.

How Security Certificates Work

  1. Using the cockroach cert command, you create a CA certificate and key and then node and client certificates that are signed by the CA certificate. Since you need access to a copy of the CA certificate and key to create node and client certs, it's best to create everything in one place.

  2. You then upload the appropriate node certificate and key and the CA certificate to each node, and you upload the appropriate client certificate and key and the CA certificate to each client.

  3. When nodes establish contact to each other, and when clients establish contact to nodes, they use the CA certificate to verify each other's identity.

Subcommands

Subcommand Usage
create-ca Create the self-signed certificate authority (CA), which you'll use to create and authenticate certificates for your entire cluster.
create-node Create a certificate and key for a specific node in the cluster. You specify all addresses at which the node can be reached and pass appropriate flags.
create-client Create a certificate and key for a specific user accessing the cluster from a client. You specify the username of the user who will use the certificate and pass appropriate flags.
list List certificates and keys found in the certificate directory.

Certificate Directory

When using cockroach cert to create node and client certificates, you will need access to a local copy of the CA certificate and key. It is therefore recommended to create all certificates and keys in one place and then distribute node and client certificates and keys appropriately. For the CA key, be sure to store it somewhere safe and keep a backup; if you lose it, you will not be able to add new nodes or clients to your cluster. For a walkthrough of this process, see Manual Deployment.

The create-* subcommands generate the CA certificate and all node and client certificates and keys in a single directory specified by the --certs-dir flag, with the files named as follows:

File name pattern File usage
ca.crt CA certificate
node.crt Server certificate
node.key Key for server certificate
client.<user>.crt Client certificate for <user> (eg: client.root.crt for user root)
client.<user>.key Key for the client certificate

Note the following:

  • The CA key is never loaded automatically by cockroach commands, so it should be created in a separate directory, identified by the --ca-key flag.

  • Keys (files ending in .key) must not have group or world permissions (maximum permissions are 0700, or rwx------). This check can be disabled by setting the environment variable COCKROACH_SKIP_KEY_PERMISSION_CHECK=true.

Synopsis

# Create the CA certificate and key:
$ cockroach cert create-ca \
 --certs-dir=[path-to-certs-directory] \
 --ca-key=[path-to-ca-key]

# Create a node certificate and key:
$ cockroach cert create-node \
 [node-hostname] \
 [node-other-hostname] \
 [node-yet-another-hostname] \
 --certs-dir=[path-to-certs-directory] \
 --ca-key=[path-to-ca-key]

# Create a client certificate and key:
$ cockroach cert create-client \
 [username] \
 --certs-dir=[path-to-certs-directory] \
 --ca-key=[path-to-ca-key]

# List certificates and keys:
$ cockroach cert list \
 --certs-dir=[path-to-certs-directory]

# View help:
$ cockroach cert --help
$ cockroach cert create-ca --help
$ cockroach cert create-node --help
$ cockroach cert create-client --help
$ cockroach cert list --help

Flags

The cert command and subcommands support the following general-use and logging flags.

General

Flag Description
--certs-dir The path to the certificate directory containing all certificates and keys needed by cockroach commands.

This flag is used by all subcommands.

Default: ${HOME}/.cockroach-certs/
--ca-key The path to the private key protecting the CA certificate.

This flag is required for all create-* subcommands. When used with create-ca in particular, it defines where to create the CA key; the specified directory must exist.

Env Variable: COCKROACH_CA_KEY
--allow-ca-key-reuse When running the create-ca subcommand, pass this flag to re-use an existing CA key identified by --ca-key. Otherwise, a new CA key will be generated.

This flag is used only by the create-ca subcommand. It helps avoid accidentally re-using an existing CA key.
--overwrite When running create-* subcommands, pass this flag to allow existing files in the certificate directory (--certs-dir) to be overwritten.

This flag helps avoid accidentally overwriting sensitive certificates and keys.
--lifetime The lifetime of the certificate, in hours, minutes, and seconds.

Certificates are valid from the time they are created through the duration specified in --lifetime.

Default: 87840h0m0s (10 years)
--key-size The size of the CA, node, or client key, in bits.

Default: 2048

Logging

By default, the cert command logs errors to stderr.

If you need to troubleshoot this command's behavior, you can change its logging behavior.

Examples

Create the CA certificate and key pair

  1. Create two directories:

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    $ mkdir certs
    
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    $ mkdir my-safe-directory
    
    • certs: You'll generate your CA certificate and all node and client certificates and keys in this directory and then upload some of the files to your nodes.
    • my-safe-directory: You'll generate your CA key in this directory and then reference the key when generating node and client certificates. After that, you'll keep the key safe and secret; you will not upload it to your nodes.
  2. Generate the CA certificate and key:

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    $ cockroach cert create-ca \
    --certs-dir=certs \
    --ca-key=my-safe-directory/ca.key
    
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    $ ls -l certs
    
    total 8
    -rw-r--r--  1 maxroach  maxroach  1.1K Jul 10 14:12 ca.crt
    

Create the certificate and key pairs for nodes

  1. Generate the certificate and key for the first node:

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    $ cockroach cert create-node \
    node1.example.com \
    node1.another-example.com \
    --certs-dir=certs \
    --ca-key=my-safe-directory/ca.key
    
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    $ ls -l certs
    
    total 24
    -rw-r--r--  1 maxroach  maxroach  1.1K Jul 10 14:12 ca.crt
    -rw-r--r--  1 maxroach  maxroach  1.2K Jul 10 14:16 node.crt
    -rw-------  1 maxroach  maxroach  1.6K Jul 10 14:16 node.key
    
  2. Upload certificates to the first node:

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    # Create the certs directory:
    $ ssh <username>@<node1 address> "mkdir certs"
    
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    # Upload the CA certificate and node certificate and key:
    $ scp certs/ca.crt \
    certs/node.crt \
    certs/node.key \
    <username>@<node1 address>:~/certs
    
  3. Delete the local copy of the first node's certificate and key:

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    $ rm certs/node.crt certs/node.key
    
    Note:
    This is necessary because the certificates and keys for additional nodes will also be named node.crt and node.key As an alternative to deleting these files, you can run the next cockroach cert create-node commands with the --overwrite flag.
  4. Create the certificate and key for the second node:

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    $ cockroach cert create-node \
    node2.example.com \
    node2.another-example.com \
    --certs-dir=certs \
    --ca-key=my-safe-directory/ca.key
    
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    $ ls -l certs
    
    total 24
    -rw-r--r--  1 maxroach  maxroach  1.1K Jul 10 14:12 ca.crt
    -rw-r--r--  1 maxroach  maxroach  1.2K Jul 10 14:17 node.crt
    -rw-------  1 maxroach  maxroach  1.6K Jul 10 14:17 node.key
    
  5. Upload certificates to the second node:

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    # Create the certs directory:
    $ ssh <username>@<node2 address> "mkdir certs"
    
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    # Upload the CA certificate and node certificate and key:
    $ scp certs/ca.crt \
    certs/node.crt \
    certs/node.key \
    <username>@<node2 address>:~/certs
    
  6. Repeat steps 3 - 5 for each additional node.

Create the certificate and key pair for a client

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$ cockroach cert create-client \
maxroach \
--certs-dir=certs \
--ca-key=my-safe-directory/ca.key
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$ ls -l certs
total 40
-rw-r--r--  1 maxroach  maxroach  1.1K Jul 10 14:12 ca.crt
-rw-r--r--  1 maxroach  maxroach  1.1K Jul 10 14:13 client.maxroach.crt
-rw-------  1 maxroach  maxroach  1.6K Jul 10 14:13 client.maxroach.key
-rw-r--r--  1 maxroach  maxroach  1.2K Jul 10 14:17 node.crt
-rw-------  1 maxroach  maxroach  1.6K Jul 10 14:17 node.key

List certificates and keys

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$ cockroach cert list \
--certs-dir=certs
Certificate directory: certs
+-----------------------+---------------------+---------------------+------------+--------------------------------------------------------+-------+
|         Usage         |  Certificate File   |      Key File       |  Expires   |                         Notes                          | Error |
+-----------------------+---------------------+---------------------+------------+--------------------------------------------------------+-------+
| Certificate Authority | ca.crt              |                     | 2027/07/18 | num certs: 1                                           |       |
| Node                  | node.crt            | node.key            | 2022/07/14 | addresses: node2.example.com,node2.another-example.com |       |
| Client                | client.maxroach.crt | client.maxroach.key | 2022/07/14 | user: maxroach                                         |       |
+-----------------------+---------------------+---------------------+------------+--------------------------------------------------------+-------+
(3 rows)

See Also



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