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Token authentication admin

Token Authentication Overview

Pulsar supports authenticating clients using security tokens that are based on JSON Web Tokens (RFC-7519).

Tokens are used to identify a Pulsar client and associate with some "principal" (or "role") which will be then granted permissions to do some actions (eg: publish or consume from a topic).

A user will typically be given a token string by an administrator (or some automated service).

The compact representation of a signed JWT is a string that looks like:


The application specifies the token when creating the client instance. An alternative is to pass a "token supplier", that is to say, a function that returns the token when the client library will need one.

Always use TLS transport encryption

Sending a token is equivalent to sending a password over the wire. It is strongly recommended to always use TLS encryption when talking to the Pulsar service. See Transport Encryption using TLS

Secret vs Public/Private keys

JWT supports two different kinds of keys to generate and validate the tokens:

  • Symmetric:
    • there is a single Secret key that is used both to generate and validate
  • Asymmetric: there is a pair of keys.
    • Private key is used to generate tokens
    • Public key is used to validate tokens

Secret key

When using a secret key, the administrator will create the key and he will use it to generate the client tokens. This key will be also configured to the brokers to allow them to validate the clients.

Creating a secret key

Output file will be generated in the root of your pulsar installation directory. You can also provide absolute path for the output file.

bin/pulsar tokens create-secret-key --output my-secret.key

To generate base64 encoded private key

bin/pulsar tokens create-secret-key --output  /opt/my-secret.key --base64

Public/Private keys

With public/private, we need to create a pair of keys. Pulsar supports all algorithms supported by the Java JWT library shown here

Creating a key pair

Output file will be generated in the root of your pulsar installation directory. You can also provide absolute path for the output file.

bin/pulsar tokens create-key-pair --output-private-key my-private.key --output-public-key my-public.key
  • my-private.key will be stored in a safe location and only used by administrators to generate new tokens.
  • my-public.key will be distributed to all Pulsar brokers. This file can be publicly shared without any security concerns.

Generating tokens

A token is a credential associated with a user. The association is done through the "principal", or "role". In the case of JWT tokens, this field it's typically referred to as subject, though it's exactly the same concept.

The generated token is then required to have a subject fieldset.

bin/pulsar tokens create --secret-key file:///path/to/my-secret.key \
--subject test-user

This will print the token string on stdout.

Similarly, one can create a token by passing the "private" key:

bin/pulsar tokens create --private-key file:///path/to/my-private.key \
--subject test-user

Finally, a token can also be created with a pre-defined TTL. After that time, the token will be automatically invalidated.

bin/pulsar tokens create --secret-key file:///path/to/my-secret.key \
--subject test-user \
--expiry-time 1y


The token itself doesn't have any permission associated. That will be determined by the authorization engine. Once the token is created, one can grant permission for this token to do certain actions. Eg. :

bin/pulsar-admin namespaces grant-permission my-tenant/my-namespace \
--role test-user \
--actions produce,consume

Enabling Token Authentication ...

... on Brokers

To configure brokers to authenticate clients, put the following in broker.conf:

# Configuration to enable authentication and authorization

# If using secret key (Note: key files must be DER-encoded)
# The key can also be passed inline:
# tokenSecretKey=data:;base64,FLFyW0oLJ2Fi22KKCm21J18mbAdztfSHN/lAT5ucEKU=

# If using public/private (Note: key files must be DER-encoded)
# tokenPublicKey=file:///path/to/public.key

... on Proxies

To configure proxies to authenticate clients, put the following in proxy.conf:

The proxy will have its own token used when talking to brokers. The role token for this key pair should be configured in the proxyRoles of the brokers. See the authorization guide for more details.

# For clients connecting to the proxy

# For the proxy to connect to brokers
# Or, alternatively, read token from file
# brokerClientAuthenticationParameters=file:///path/to/proxy-token.txt