apache/pulsar · error · IllegalArgumentException

Unsupported authentication type: ${type}

Error message

Unsupported authentication type: ${type}

What it means

AuthenticationOAuth2.configure() first checks that the params 'type' equals 'oauth2'. If the type value is anything else (or missing/blank so it fails the equality check), it throws this IllegalArgumentException ('Unsupported authentication type: <type>').

Source

Thrown at pulsar-client/src/main/java/org/apache/pulsar/client/impl/auth/oauth2/AuthenticationOAuth2.java:185

    }

    @Override
    public void configure(String encodedAuthParamString) {
        Map<String, String> params = parseAuthParameters(encodedAuthParamString);
        String type = params.getOrDefault(CONFIG_PARAM_TYPE, TYPE_CLIENT_CREDENTIALS);
        if (TYPE_CLIENT_CREDENTIALS.equals(type)) {
            TokenEndpointAuthMethod authMethod = TokenEndpointAuthMethod.fromValue(
                    params.getOrDefault(CONFIG_PARAM_TOKEN_ENDPOINT_AUTH_METHOD,
                            TokenEndpointAuthMethod.CLIENT_SECRET_POST.value()));
            if (authMethod == TokenEndpointAuthMethod.CLIENT_SECRET_POST) {
                this.flow = ClientCredentialsFlow.fromParameters(params);
            } else if (authMethod == TokenEndpointAuthMethod.TLS_CLIENT_AUTH) {
                this.flow = TlsClientAuthFlow.fromParameters(params);
            } else {
                throw new IllegalArgumentException("Unsupported auth method: " + authMethod);
            }
        } else {
            throw new IllegalArgumentException("Unsupported authentication type: " + type);
        }
    }

    protected Map<String, String> parseAuthParameters(String encodedAuthParamString) {
        if (StringUtils.isBlank(encodedAuthParamString)) {
            throw new IllegalArgumentException("No authentication parameters were provided");
        }
        Map<String, String> params;
        try {
            params = AuthenticationUtil.configureFromJsonString(encodedAuthParamString);
        } catch (IOException e) {
            throw new IllegalArgumentException("Malformed authentication parameters", e);
        }

        String earlyRefreshPercentStr = params.get(CONFIG_PARAM_EARLY_TOKEN_REFRESH_PERCENT);
        if (earlyRefreshPercentStr != null) {
            double percent = parseEarlyRefreshPercent(earlyRefreshPercentStr);
            this.earlyTokenRefreshPercent = percent;

View on GitHub (pinned to 820761864e)

Solutions

1. Set "type":"oauth2" in the auth params JSON.
2. If the credentials are not OAuth2, use the matching authentication plugin instead of AuthenticationOAuth2.
3. Verify the params string actually contains the type key and is valid JSON.

Example fix

// before
auth.configure("{"type":"token","token":"xyz"}"); // throws
// after
auth.configure("{"type":"oauth2","issuerUrl":"https://...","clientId":"...","clientSecret":"..."}");

JSONObject params = new JSONObject(json);
if (!"oauth2".equals(params.optString("type"))) {
    throw new IllegalStateException("AuthenticationOAuth2 requires \"type\":\"oauth2\" in auth params");
}
auth.configure(json);

try {
    auth.configure(json);
} catch (IllegalArgumentException e) {
    if (e.getMessage().startsWith("Unsupported authentication type")) {
        throw new ConfigurationException("Auth params must contain \"type\":\"oauth2\" for the OAuth2 plugin", e);
    }
    throw e;
}

When it happens

Trigger: Calling configure() with a params JSON whose 'type' key is not 'oauth2' — e.g. 'token', 'basic', or absent.

Common situations: Passing a generic auth params string intended for a different plugin (e.g. ATHENZ/TLS) into the OAuth2 plugin; copying a config sample with a different 'type' value; the type key omitted entirely.

Understand the failure class

• Authentication and authorization failures — expired tokens, bad credentials, and missing scopes.

Related errors

• Unsupported auth method: ${authMethod}
• No authentication parameters were provided
• Unsupported token endpoint auth method: ${value}
• certFilePath must not be null
• keyFilePath must not be null

AI-assisted analysis of apache/pulsar@820761864e (2026-09-06). Data as JSON: /api/errors/5fefdbddce48f223. Report an issue: GitHub.