A SetaPDF-Signer component signature module for a CSC API.

v1.2 2023-04-18 15:25 UTC

This package is auto-updated.

Last update: 2023-05-19 11:57:00 UTC


This package offers a module for the SetaPDF-Signer component that allows you to use the Cloud Signature Consortium API for Remote Electronic Signatures and Remote Electronic Seals to digital sign PDF documents in pure PHP.

The API documentation can be found on the Cloud Signature Consortium website:

At the time of writing the module is tested with the eSigner CSC API from and the Remote Signing Service CSC API from Entrust. It currently does not support all features or variances that may appear in other API implementations.

For usage with you can follow this integration guide to get a better understanding of how to setup a test environment and how the signature workflow works: (instead of using postman you can use this module directly and sign your PDF documents locally).

Known not implemented features

At the moment the module does not support RSA_PSS or ECDSA as signing algorithm because of missing testing options. Both are implemented but will throw an exception to get a chance for a test case. Please contact us at so that we can work on a final implementation together.

Authentification is only supported over OAuth2. Authentification over HTTP Basic or Digest authentification is not implemented yet. An implementation of the auth/login (11.2) endpoint shouldn't require much efford. If you need this, feel free to contact us at so that we can work on this together.

Online One-Time Password (OTP) generation mechanism is not implemented yet. You'll have to trigger the OTP generation by yourself - see API credentials/sendOTP (11.8).


To use this package you need access to a CSC API.

This package is developed and tested on PHP >= 7.1. Requirements of the SetaPDF-Signer component can be found here.

We're using PSR-17 (HTTP Factories) and PSR-18 (HTTP Client) for the requests. So you'll need an implementation of these. We recommend using Guzzle.

For PHP 7.1

    "require" : {
        "guzzlehttp/guzzle": "^6.5",
        "http-interop/http-factory-guzzle": "^1.0",
        "mjelamanov/psr18-guzzle": "^1.3"

For >= PHP 7.2

    "require" : {
        "guzzlehttp/guzzle": "^7.0",
        "http-interop/http-factory-guzzle": "^1.0"


Add following to your composer.json:

    "require": {
        "setasign/setapdf-signer-addon-csc": "^1.1"
    "repositories": [
            "type": "composer",
            "url": ""

and execute composer update. You need to define the repository to resolve the dependency to the SetaPDF-Signer component (see here for more details).


All classes in this package are located in the namespace setasign\SetaPDF\Signer\Module\CSC.

The Client class

This class is a kind of proxy class to the CSC API. Its constructor requires the following arguments:

  • $apiUri The base url of your csc api e.g.
  • $httpClient PSR-18 HTTP Client implementation.
  • $requestFactory PSR-17 HTTP Factory implementation.
  • $streamFactory PSR-17 HTTP Factory implementation.

If you need to call an endpoint which is not covered by a proxy method, you can use the call(string $path, ?string $accessToken = null, array $inputData = []) method.

How do I get an access token?

An access token is returned by an authorization to the API service.

This was tested only by an OAuth2 authorization yet. You can to use an OAuth2 implementation such as league/oauth2-client. Sample code for this can be found in "examples/generate-token.php".

Authorization modes

Accessing a credential for remote signing requires an authorization from the user who owns it to control the signing key associated to it.

The CSC API supports multiple authorization modes. The authorization mode also defines whether the signing process must be asynchronous or not. To get this information you can call Client::credentialsInfo() and in the key "authMode" you'll find one of the following authorization modes:

  • implicit: the authorization process is managed by the remote service autonomously. Authentication factors are managed by the remote signing service provider by interacting directly with the user, and not by the signature application.
  • explicit: the authorization process is managed by the signature application, which collects authentication factors like PIN or One-Time Passwords (OTP).
  • oauth2code: the authorization process is managed by the remote service using an OAuth 2.0 mechanism based on authorization code.

For both "implicit" and "explicit" you can use the synchronous process (see examples/demo.php and examples/ltv-demo.php).

For "oauth2code" you must use the asynchronous process (see examples/demo-async.php). This will require an oauth2 implementation such as league/oauth2-client.

More about the authorization modes can be found in "8.2 Credential authorization" of the CSC API.


This package is open-sourced software licensed under the MIT license.