SDK for C# / .NET Reference Guide

You can use the SDK for C# / .NET on the server side to decrypt EUID tokens to access the raw EUID.

Overview

The functions outlined here define the information that you'll need to configure or can retrieve from the library. The parameters and property names defined below are pseudocode. Actual parameters and property names vary by language but will be similar to the information outlined here.

Functionality

This SDK simplifies integration with EUID for any DSPs who are using C# / .NET for their server-side coding. The following table shows the functions it supports.

Encrypt Raw EUID to EUID Token	Decrypt EUID Token to Raw EUID	Generate EUID Token from Personal Data	Refresh EUID Token	Map Personal Data to Raw EUIDs	Monitor Rotated Salt Buckets
✅	✅	—	—	—	—

API Permissions

To use this SDK, you'll need to complete the EUID account setup by following the steps described in the Account Setup page.

You'll be granted permission to use specific functions offered by the SDK, and given credentials for that access. Bear in mind that there might be functions in the SDK that you don't have permission to use.

For details, see API Permissions.

Version

The library uses .NET Standard 2.1. unit tests. The sample app uses .NET 5.0.

GitHub Repository/Binary

This SDK is in the following open-source GitHub repository:

• SDK for .NET

  NOTE: This SDK is valid for both UID2 and EUID. The SDK, and some of its technical components, are named UID2, but are equally applicable for EUID.

The binary is published in this location:

• https://www.nuget.org/packages/UID2.Client

Initialization

DSPs should create an instance of the BidstreamClient class.

You will need to provide the values necessary for the SDK to authenticate with the EUID service.

Parameter	Description
endpoint	The endpoint for the EUID service. See Environments.
authKey	The API key. See EUID Credentials.
secretKey	The client secret. See EUID Credentials.

Interface

The BidstreamClient class allows you to decrypt EUID tokens into raw EUIDs.

For details on the bidding logic for handling user opt-outs, see DSP Integration Guide.

note

When you use an SDK, you do not need to store or manage decryption keys.

Decryption Response Content

Whether decrypting with the BidstreamClient, the SDK returns the following information:

Property	Description
Status	The decryption result status. For a list of possible values and definitions, see Decryption Response Statuses.
Uid	The raw EUID for the corresponding EUID token.
Established	The timestamp indicating when a user first established the EUID with the publisher.

Decryption Response Statuses

Value	Description
Success	The EUID token was decrypted successfully and a raw EUID was returned.
NotAuthorizedForKey	The requester does not have authorization to decrypt this EUID token.
NotInitialized	The client library is waiting to be initialized.
InvalidPayload	The incoming EUID token is not a valid payload.
ExpiredToken	The incoming EUID token has expired.
KeysNotSynced	The client has failed to synchronize keys from the EUID service.
VersionNotSupported	The client library does not support the version of the encrypted token.

Usage for DSPs

The following instructions provide an example of how you can decode bidstream tokens using the SDK for .NET as a DSP.

1. Create a BidstreamClient:

var client = new BidstreamClient(EUID_BASE_URL, EUID_API_KEY, EUID_SECRET_KEY);

2. Refresh once at startup, and then periodically (recommended refresh interval is hourly):

client.Refresh();

3. Decrypt a token into a raw EUID. Pass the token, and then do one of the following:

• If the bid request originated from a publisher's website, pass the domain name. The domain name must be all lower case, without spaces and without subdomain. For example, for Subdomain.DOMAIN.com, pass domain.com instead.
• If the bid request originated from a mobile app, pass the app name.
• Otherwise, pass null.

var decrypted = client.DecryptTokenIntoRawUid(uidToken, domainOrAppName);
// If decryption succeeded, use the raw EUID.
if (decrypted.Success) 
{
    // Use decrypted.Uid.
} 
else 
{
    // Check decrypted.Status for the failure reason.
}

For a full example, see the ExampleBidStreamClient method in SampleApp/Program.cs.

FAQs

For a list of frequently asked questions for DSPs, see FAQs for DSPs.