@web5/credentials
Version:
Verifiable Credentials
137 lines • 7.6 kB
JavaScript
import { PEX } from '@sphereon/pex';
/**
* The Presentation Exchange (PEX) Library implements the functionality described in the DIF Presentation Exchange specification
*/
export class PresentationExchange {
/**
* Selects credentials that satisfy a given presentation definition.
*
* @param params - The parameters for the credential selection.
* @param params.vcJwts The list of Verifiable Credentials to select from.
* @param params.presentationDefinition The Presentation Definition to match against.
* @returns {string[]} selectedVcJwts A list of Verifiable Credentials that satisfy the Presentation Definition.
*/
static selectCredentials({ vcJwts, presentationDefinition }) {
var _a, _b;
this.resetPex();
const selectResults = this.pex.selectFrom(presentationDefinition, vcJwts);
// If errors exist in the results object the credentials provided didn't satisfy the requirements in the Presentation Definition
if (((_a = selectResults.errors) === null || _a === void 0 ? void 0 : _a.length) !== 0) {
return [];
}
return Array.from(new Set((_b = selectResults.verifiableCredential) !== null && _b !== void 0 ? _b : []));
}
/**
* Validates if a list of VC JWTs satisfies the given presentation definition.
*
* @param params - The parameters for the satisfaction check.
* @param params.vcJwts - An array of VC JWTs as strings.
* @param params.presentationDefinition - The criteria to validate against.
* @throws Error if the evaluation results in warnings or errors.
*/
static satisfiesPresentationDefinition({ vcJwts, presentationDefinition }) {
var _a, _b, _c;
this.resetPex();
const evaluationResults = this.pex.evaluateCredentials(presentationDefinition, vcJwts);
if ((_a = evaluationResults.warnings) === null || _a === void 0 ? void 0 : _a.length) {
console.warn('Warnings were generated during the evaluation process: ' + JSON.stringify(evaluationResults.warnings));
}
if (evaluationResults.areRequiredCredentialsPresent.toString() !== 'info' || ((_b = evaluationResults.errors) === null || _b === void 0 ? void 0 : _b.length)) {
let errorMessage = 'Failed to create Verifiable Presentation JWT due to: ';
if (evaluationResults.areRequiredCredentialsPresent) {
errorMessage += 'Required Credentials Not Present: ' + JSON.stringify(evaluationResults.areRequiredCredentialsPresent);
}
if ((_c = evaluationResults.errors) === null || _c === void 0 ? void 0 : _c.length) {
errorMessage += 'Errors: ' + JSON.stringify(evaluationResults.errors);
}
throw new Error(errorMessage);
}
}
/**
* Creates a presentation from a list of Verifiable Credentials that satisfy a given presentation definition.
* This function initializes the Presentation Exchange (PEX) process, validates the presentation definition,
* evaluates the credentials against the definition, and finally constructs the presentation result if the
* evaluation is successful.
*
* @param params - The parameters for the presentation creation.
* @param params.vcJwts The list of Verifiable Credentials (VCs) in JWT format to be evaluated.
* @param params.presentationDefinition The Presentation Definition V2 to match the VCs against.
* @returns {PresentationResult} The result of the presentation creation process, containing a presentation submission
* that satisfies the presentation definition criteria.
* @throws {Error} If the evaluation results in warnings or errors, or if the required credentials are not present,
* an error is thrown with a descriptive message.
*/
static createPresentationFromCredentials({ vcJwts, presentationDefinition }) {
var _a, _b, _c;
this.resetPex();
const pdValidated = PEX.validateDefinition(presentationDefinition);
isValid(pdValidated);
const evaluationResults = this.pex.evaluateCredentials(presentationDefinition, vcJwts);
if ((_a = evaluationResults.warnings) === null || _a === void 0 ? void 0 : _a.length) {
console.warn('Warnings were generated during the evaluation process: ' + JSON.stringify(evaluationResults.warnings));
}
if (evaluationResults.areRequiredCredentialsPresent.toString() !== 'info' || ((_b = evaluationResults.errors) === null || _b === void 0 ? void 0 : _b.length)) {
let errorMessage = 'Failed to create Verifiable Presentation JWT due to: ';
if (evaluationResults.areRequiredCredentialsPresent) {
errorMessage += 'Required Credentials Not Present: ' + JSON.stringify(evaluationResults.areRequiredCredentialsPresent);
}
if ((_c = evaluationResults.errors) === null || _c === void 0 ? void 0 : _c.length) {
errorMessage += 'Errors: ' + JSON.stringify(evaluationResults.errors);
}
throw new Error(errorMessage);
}
const presentationResult = this.pex.presentationFrom(presentationDefinition, vcJwts);
const submissionValidated = PEX.validateSubmission(presentationResult.presentationSubmission);
isValid(submissionValidated);
return presentationResult;
}
/**
* This method validates whether an object is usable as a presentation definition or not.
*
* @param {PresentationDefinitionV2} presentationDefinition: presentationDefinition to be validated.
* @returns {Validated} the validation results to reveal what is acceptable/unacceptable about the passed object to be considered a valid presentation definition
*/
static validateDefinition({ presentationDefinition }) {
return PEX.validateDefinition(presentationDefinition);
}
/**
* This method validates whether an object is usable as a presentation submission or not.
*
* @param {PresentationSubmission} presentationSubmission the object to be validated.
* @returns {Validated} the validation results to reveal what is acceptable/unacceptable about the passed object to be considered a valid presentation submission
*/
static validateSubmission({ presentationSubmission }) {
return PEX.validateSubmission(presentationSubmission);
}
/**
* Evaluates a presentation against a presentation definition.
*
* @returns {EvaluationResults} The result of the evaluation process.
*/
static evaluatePresentation({ presentationDefinition, presentation }) {
this.resetPex();
return this.pex.evaluatePresentation(presentationDefinition, presentation);
}
/** Resets the PEX instance. */
static resetPex() {
this.pex = new PEX();
}
}
/** The Presentation Exchange (PEX) instance. */
PresentationExchange.pex = new PEX();
function isValid(validated) {
let errorMessage = 'Failed to pass validation check due to: ';
if (Array.isArray(validated)) {
if (!validated.every(item => item.status === 'info')) {
errorMessage += 'Validation Errors: ' + JSON.stringify(validated);
throw new Error(errorMessage);
}
}
else {
if (validated.status !== 'info') {
errorMessage += 'Validation Errors: ' + JSON.stringify(validated);
throw new Error(errorMessage);
}
}
}
//# sourceMappingURL=presentation-exchange.js.map