Validating GS1 License Credentials

GS1 License Credential validation is the process of confirming that a specific license is current, authentic, and relevant. Because GS1 Licenses are issued in a federated manner, license validation requires examining the set (chain) of licenses back to the GO root of trust.

Philosophy of License Validation

GS1 License Credential validation is the process by which a machine can verify that a GS1 License is authentic as part of the GS1 identity system. Generally, this involves validating the chain of GS1 License Credentials starting with the most specific license up to the root license issued by GS1 GO. In addition to checking the fields of the license documents, the documents must link together using the extendsCredential property forming a chain back to the root license. This chain must have properties so that each licenseValue stems from its previous licenseValue. This validation process is presented in detail in the sections below.

For example, in the chain with prefix license 022, GCP 02234545 and individual GTIN 02234545645654, we can see the licenseValue of the GTIN starts with the licenseValue of the GCP which starts with the licenseValue from the prefix license, indicating a complete and valid chain.

Validating a license chain ensures that assertions from the licensee are authentic and attributable to the party identified by the organization within the GS1 License Credential subject field. For specifics of GS1 identity validation policies consult your local MO.

License Validation Rules

The following section contains rules for validation of GS1 License Credentials. If any of the conditions referenced in the following lists are false, the credential is invalid and should not be trusted.

The following steps MUST be performed to validate a GS1 License Credential denoted as L:

Prefix License Validation Rules

The following additional steps MUST be performed to validate a GS1 Prefix License Credential denoted as PL:

GCP Validation Rules

The following additional steps MUST be performed to validate a GCP License Credential denoted as GL where the credential referenced by GL's extendsCredential property is denoted as EL:

Identification Key License Validation Rules

The following additional steps MUST be performed to validate a GS1 Identification Key License Credential denoted as IL where the credential referenced by IL's extendsCredential property is denoted as EL:

License Validation Libraries and Tools

GS1 has developed tools for license validation hosted at https://github.com/gs1/vc-data-model-verifier