Toucan Authentication
Toucan provides critical payment credentials and security data (cryptograms) for Pagos customers to use when allowing cardholders to transact. As such, we have gone beyond the simple API key approach to authentication and instead leveraged a common HTTP REST-API pattern (AWS, Docusign, etc.) based on a keyed-HMAC (Hash Message Authentication Code) for authentication.
This guide outlines how a developer authenticates and proves their identity to access the Toucan service.
Authentication Credentials
When you first onboard with Pagos Toucan, you’ll obtain the following credentials:
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A public ClientKey
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A private SecretKey
With every request you submit to Toucan, you must submit your public ClientKey, along with a message signature that you generate using your public ClientKey and your private Secret Key combined with the request message itself (e.g. the date and the JSON payload). These details will be combined inside the HTTP headers as part of every request, as shown below.
Once Pagos receives a request we’ll also calculate a signature; if they match, we’ll proceed with the request. Otherwise, an error will be returned and we’ll drop the request as not authorized.
Check out our provisioning a network token code example to see how the signature appears in a request to Toucan.
Authentication Signature HTTP Headers
All calls to Toucan must include an HMAC signature and at least these three headers:
| Header | Format | Example | Description |
|---|---|---|---|
| X-Date | UTC timestamp in ISO 8601 format | 022-07-28T16:05:32.00Z (with optional microseconds and Z) | The date and time of the request |
| X-Client-Key | 32 character string | 538A4B83FEC409ECE24CE373A883A432 | The public ClientKey you obtained during onboarding |
| Authorization | String | V1-HMAC-SHA256, Signature: Qj23jk3…(base64 encoded) | What your code will generate when making the request |
| X-Merchant-ID | String | ”9bb8592c-cb99-48f7-907e-f97de930fc5c” | Identifies the merchant making the request |
Authentication Signature Algorithm
The requester code will combine the following data elements to form a string, and then use a HMAC library to compute the sha256 digest in base64 format:
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ClientKey
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Date
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Request Payload
Merchant Identification
To better our Pagos users with merchant-to-platform hierarchies, we include an X-Merchant-ID attribute in the header that sits underneath the API User. The relationship between API User and merchant is 1..n; an API User can have n merchants but a merchant will be associated with only one API User. Pagos uses this merchant ID to pull the applicable network-specific TRIDs to send to the card networks for network tokenization.
We’ll assign this unique merchant ID to you at the time of onboarding. If your business doesn’t operate as a platform, you’ll always use the same ID in the header of each call.