@hellocoop/web-identity

⚠️ DEPRECATED - This package has been superseded by @hellocoop/email-verification.

Development Note: This package was collaboratively developed using spec-driven development with AI assistance. You can view the complete requirements, design, and implementation specifications that guided the development process.

TypeScript functions for generating and verifying JWT tokens used in the Verified Email Autocomplete protocol. This package provides complete implementations for RequestToken, IssuanceToken (SD-JWT), and PresentationToken (SD-JWT+KB) as defined in the web-identity specification.

🚀 Try It Live with Hellō

Want to see the Verified Email Autocomplete protocol in action? You can test it right now with hello.coop!

Quick Test Setup

1. Add DNS Record: Add this TXT record to your domain:

   email._web-identity.yourdomain.com TXT "iss=hello.coop"

2. Get User Hint Cookie: Visit Hellō Wallet, create a wallet if needed by logging in, and verify an email address at your domain. In your browser, inspect the page, select the application tab, and find the user-hint cookie for wallet.hello.coop, and get its value.

3. Run the Test: Use npx to test the complete flow:

   npx @hellocoop/web-identity [email protected] user-hint <cookie-value>

Example

# After setting up DNS and getting your user-hint cookie
npx @hellocoop/web-identity [email protected] user-hint eyJhbGciOiJFZERTQSJ9...

This will:

• ✅ Discover the issuer (hello.coop) via DNS
• ✅ Fetch hello.coop web-identity metadata and JWKS
• ✅ Generate a request token with a browser key pair
• ✅ Send the request to hello.coop issuance endpoint
• ✅ Verify and display the returned SD-JWT token

Perfect for testing your DNS setup and seeing the protocol in action! 🎯

Package Installation

npm install @hellocoop/web-identity

Quick Start

ESM (ECMAScript Modules)

import {
    // Most commonly used by RPs
    verifyPresentationToken,

    // Other token functions
    generateRequestToken,
    verifyRequestToken,
    generateIssuanceToken,
    verifyIssuanceToken,
    generatePresentationToken,

    // DNS discovery functions
    discoverIssuer,
    fetchWebIdentityMetadata,
    fetchJWKS,
    clearCaches,

    // Types
    type KeyResolver,
    type WebIdentityMetadata,
    type JWKSResponse,
    type RequestOptions,
} from '@hellocoop/web-identity'

CommonJS

const {
    // Most commonly used by RPs
    verifyPresentationToken,

    // Other token functions
    generateRequestToken,
    verifyRequestToken,
    generateIssuanceToken,
    verifyIssuanceToken,
    generatePresentationToken,

    // Discovery functions
    discoverIssuer,
    fetchWebIdentityMetadata,
    fetchJWKS,
    clearCaches,
} = require('@hellocoop/web-identity')

Note: The package provides dual ESM/CommonJS support with automatic module resolution based on your project configuration.

API Reference

PresentationToken Verification (Most Common for RPs)

verifyPresentationToken(token, expectedAudience, expectedNonce, keyResolver?)

🔥 Most commonly used function by Relying Parties - Verifies a PresentationToken (SD-JWT+KB) from browsers with automatic DNS-based key discovery.

Parameters:

• token: string - SD-JWT+KB string to verify
• expectedAudience: string - Expected audience (RP's origin)
• expectedNonce: string - Expected nonce from RP's session
• keyResolver?: KeyResolver - Optional function to resolve issuer's public key. If not provided, uses automatic DNS discovery

Returns: Promise<PresentationTokenPayload> - Object containing both SD-JWT and KB-JWT payloads

Example (Automatic DNS Discovery - Recommended):

// Simplest usage - automatic key discovery via DNS
const verified = await verifyPresentationToken(
    presentationToken,
    'https://rp.example',
    'session-nonce-123',
)

console.log(verified.sdJwt.email) // '[email protected]'
console.log(verified.kbJwt.aud) // 'https://rp.example'

Example (Custom Key Resolver):

// Custom key resolver for advanced use cases
const keyResolver = async (kid, issuer) => {
    // Your custom logic to resolve keys
    return await getPublicKeyFromSomewhere(kid, issuer)
}

const verified = await verifyPresentationToken(
    presentationToken,
    'https://rp.example',
    'session-nonce-123',
    keyResolver,
)

RequestToken Functions

RequestTokens are used by browsers to request verified email tokens from issuers (step 3.4 & 4.1).

generateRequestToken(payload, jwk, options?)

Generates a RequestToken (JWT) with an embedded public key.

Parameters:

• payload: RequestTokenPayload - Token payload
  • aud: string - Audience (issuer domain)
  • nonce: string - Nonce provided by the RP
  • email: string - Email address to be verified
  • iat?: number - Optional issued at time (defaults to current time)
• jwk: JWK - JSON Web Key containing private key, algorithm, and key ID
• options?: TokenGenerationOptions - Optional generation options

Returns: Promise<string> - Signed JWT string

Example:

const requestToken = await generateRequestToken(
    {
        aud: 'issuer.example',
        nonce: '259c5eae-486d-4b0f-b666-2a5b5ce1c925',
        email: '[email protected]',
    },
    browserPrivateKey,
)

verifyRequestToken(token)

Verifies a RequestToken using the embedded public key.

Parameters:

• token: string - JWT string to verify

Returns: Promise<RequestTokenPayload> - Verified payload

Example:

const verified = await verifyRequestToken(requestToken)
console.log(verified.email) // '[email protected]'

Note: RequestTokens contain the public key embedded in the JWT header, so no external key resolver is needed.

IssuanceToken Functions

IssuanceTokens (SD-JWTs) are used by issuers to provide verified email tokens to browsers (step 4.2 & 5.1).

generateIssuanceToken(payload, jwk, options?)

Generates an IssuanceToken (SD-JWT) for verified email addresses.

Parameters:

• payload: IssuanceTokenPayload - Token payload
  • iss: string - Issuer identifier
  • cnf: { jwk: JWK } - Confirmation claim with browser's public key
  • email: string - Verified email address
  • email_verified: boolean - Must be true
  • iat?: number - Optional issued at time
• jwk: JWK - Issuer's private key
• options?: TokenGenerationOptions - Optional generation options

Returns: Promise<string> - Signed SD-JWT string

Example:

const issuanceToken = await generateIssuanceToken(
    {
        iss: 'issuer.example',
        cnf: { jwk: browserPublicKey },
        email: '[email protected]',
        email_verified: true,
    },
    issuerPrivateKey,
)

verifyIssuanceToken(token, keyResolver)

Verifies an IssuanceToken (SD-JWT) from issuers.

Parameters:

• token: string - SD-JWT string to verify
• keyResolver: KeyResolver - Function to resolve issuer's public key

Returns: Promise<IssuanceTokenPayload> - Verified payload

Example:

const keyResolver: KeyResolver = async (kid, issuer) => {
    // Return the appropriate public key for verification
    return await getIssuerPublicKey(kid, issuer)
}

const verified = await verifyIssuanceToken(issuanceToken, keyResolver)

PresentationToken Functions

PresentationTokens (SD-JWT+KB) are used by browsers to present verified email tokens to relying parties (step 5.2 & 6.2-6.4).

generatePresentationToken(sdJwt, audience, nonce, jwk, options?)

Generates a PresentationToken (SD-JWT+KB) with key binding.

Parameters:

• sdJwt: string - SD-JWT from issuer
• audience: string - RP's origin
• nonce: string - Nonce from RP's session
• jwk: JWK - Browser's private key
• options?: TokenGenerationOptions - Optional generation options

Returns: Promise<string> - SD-JWT+KB string (format: {SD-JWT}~{KB-JWT})

Example:

const presentationToken = await generatePresentationToken(
    issuanceToken,
    'https://rp.example',
    'session-nonce-123',
    browserPrivateKey,
)

DNS Discovery Functions

The package provides DNS-based discovery functions to automatically find issuers and fetch their metadata according to the Verified Email Autocomplete specification.

discoverIssuer(emailOrDomain)

Discovers the web-identity issuer for an email address or domain via DNS TXT record lookup.

Parameters:

• emailOrDomain: string - Email address (e.g., [email protected]) or domain (e.g., example.com)

Returns: Promise<string> - Issuer identifier (domain)

DNS Record Format: The function looks for TXT records at email._web-identity.$EMAIL_DOMAIN with format iss=issuer.example

Example:

// Discover issuer from email address
const issuer = await discoverIssuer('[email protected]')
console.log(issuer) // 'issuer.example'

// Or from domain directly
const issuer = await discoverIssuer('example.com')

DNS Setup Example:

email._web-identity.example.com   TXT   iss=issuer.example

fetchWebIdentityMetadata(issuerIdentifier, options?)

Fetches web-identity metadata from an issuer domain's well-known endpoint.

Parameters:

• issuerIdentifier: string - Issuer domain (e.g., issuer.example)
• options?: RequestOptions - Optional request configuration
  • timeout?: number - Request timeout in milliseconds (default: 10000)
  • cacheTimeout?: number - Cache timeout in milliseconds (default: 300000)

Returns: Promise<WebIdentityMetadata> - Metadata containing endpoints and supported algorithms

Example:

const metadata = await fetchWebIdentityMetadata('issuer.example', {
    timeout: 5000, // 5 second timeout
    cacheTimeout: 60000, // 1 minute cache
})

console.log(metadata.issuance_endpoint) // 'https://accounts.issuer.example/web-identity/issuance'
console.log(metadata.jwks_uri) // 'https://accounts.issuer.example/web-identity/jwks.json'
console.log(metadata.signing_alg_values_supported) // ['EdDSA', 'RS256']

fetchJWKS(jwksUri, options?)

Fetches JWKS (JSON Web Key Set) from a JWKS URI.

Parameters:

• jwksUri: string - JWKS URI from web-identity metadata
• options?: RequestOptions - Optional request configuration
  • timeout?: number - Request timeout in milliseconds (default: 10000)
  • cacheTimeout?: number - Cache timeout in milliseconds (default: 300000)

Returns: Promise<JWKSResponse> - JWKS containing public keys

Example:

const jwks = await fetchJWKS(metadata.jwks_uri, {
    timeout: 5000,
    cacheTimeout: 300000, // 5 minute cache
})

console.log(jwks.keys.length) // Number of keys available

clearCaches()

Clears the in-memory caches for metadata and JWKS. Useful for testing or forcing fresh fetches.

Example:

// Clear all caches to force fresh fetches
clearCaches()

Complete DNS Discovery Example

import {
    discoverIssuer,
    fetchWebIdentityMetadata,
    fetchJWKS,
    verifyIssuanceToken,
} from '@hellocoop/web-identity'

// 1. Discover issuer from email domain
const issuer = await discoverIssuer('[email protected]')

// 2. Fetch issuer metadata
const metadata = await fetchWebIdentityMetadata(issuer)

// 3. Fetch issuer's public keys
const jwks = await fetchJWKS(metadata.jwks_uri)

// 4. Create key resolver using fetched JWKS
const keyResolver = async (kid?: string, issuer?: string) => {
    const key = jwks.keys.find((k) => k.kid === kid)
    if (!key) {
        throw new Error(`Key with ID '${kid}' not found`)
    }
    return key
}

// 5. Use with token verification
const verified = await verifyIssuanceToken(issuanceToken, keyResolver)

Types

KeyResolver

type KeyResolver = (kid?: string, issuer?: string) => Promise<JWK | KeyLike>

Function to resolve public keys for verification. Called with the key ID (kid) from the JWT header and optionally the issuer identifier.

Token Payloads

interface RequestTokenPayload {
    aud: string
    iat?: number
    nonce: string
    email: string
}

interface IssuanceTokenPayload {
    iss: string
    iat?: number
    cnf: { jwk: JWK }
    email: string
    email_verified: boolean
}

interface PresentationTokenPayload {
    sdJwt: IssuanceTokenPayload
    kbJwt: {
        aud: string
        nonce: string
        iat?: number
        sd_hash?: string
    }
}

Generation Options

interface TokenGenerationOptions {
    algorithm?: string // Override algorithm from JWK
    expiresIn?: number // Token expiration (default: 60 seconds)
}

DNS Discovery Types

interface WebIdentityMetadata {
    issuance_endpoint: string
    jwks_uri: string
    signing_alg_values_supported?: string[]
}

interface JWKSResponse {
    keys: JWK[]
}

interface RequestOptions {
    timeout?: number // Request timeout in milliseconds (default: 10000)
    cacheTimeout?: number // Cache timeout in milliseconds (default: 300000)
}

Error Handling

The package provides specific error classes for different failure scenarios:

import {
    WebIdentityError, // Base error class
    MissingClaimError, // Required claim missing
    InvalidSignatureError, // Signature verification failed
    TimeValidationError, // Time-based validation failed
    TokenFormatError, // Invalid token format
    JWKValidationError, // JWK validation failed
    EmailValidationError, // Email validation failed
    DNSDiscoveryError, // DNS discovery failed
    JWKSFetchError, // JWKS/metadata fetch failed
} from '@hellocoop/web-identity'

try {
    const issuer = await discoverIssuer('[email protected]')
    const metadata = await fetchWebIdentityMetadata(issuer)
    const token = await generateRequestToken(payload, key)
} catch (error) {
    if (error instanceof DNSDiscoveryError) {
        console.log(`DNS discovery failed: ${error.message}`)
    } else if (error instanceof JWKSFetchError) {
        console.log(`JWKS fetch failed: ${error.message}`)
    } else if (error instanceof MissingClaimError) {
        console.log(`Missing claim: ${error.message}`)
    } else if (error instanceof EmailValidationError) {
        console.log(`Invalid email: ${error.message}`)
    }
}

Utility Functions

The package also exports utility functions that may be useful:

import {
    // Cryptographic utilities
    validateJWK, // Validate JWK structure
    extractPublicKeyParameters, // Extract public key from JWK
    calculateSHA256Hash, // Calculate SHA-256 hash
    isValidEmail, // Validate email format

    // Time utilities
    getCurrentTimestamp, // Get current Unix timestamp
    validateIatClaim, // Validate iat claim
    TIME_VALIDATION_WINDOW, // Default time window (60 seconds)

    // DNS discovery utilities
    discoverIssuer, // Discover issuer from email/domain
    fetchWebIdentityMetadata, // Fetch issuer metadata
    fetchJWKS, // Fetch JWKS from URI
    clearCaches, // Clear in-memory caches
} from '@hellocoop/web-identity'

Module Compatibility

This package supports both ESM (ECMAScript Modules) and CommonJS environments:

• ✅ ESM: import statements (Node.js with "type": "module", modern bundlers)
• ✅ CommonJS: require() statements (traditional Node.js projects)
• ✅ TypeScript: Full type definitions included for both module systems
• ✅ Bundlers: Works with Webpack, Rollup, Vite, and other modern bundlers

The package automatically provides the correct module format based on your project configuration.

Algorithm Support

The package supports the following cryptographic algorithms:

• RSA: RS256, RS384, RS512
• EdDSA: Ed25519 (recommended for new implementations)
• ECDSA: ES256, ES384, ES512

Security Features

• ✅ Automatic private key stripping - Private key material is automatically removed from cnf claims
• ✅ Time-based validation - All tokens validated within 60-second windows
• ✅ Email format validation - Comprehensive email validation with security checks
• ✅ JWK validation - Thorough validation of key parameters
• ✅ Cross-algorithm support - Mix and match RSA and EdDSA keys
• ✅ Independent verification - Separate test suite validates token generation

Security Considerations

• Libraries do not confirm issuer domain is eTLD+1. Browsers will enforce in actual deployments.

Performance

Typical performance benchmarks on modern hardware:

• RequestToken generation: ~1.3ms average
• RequestToken verification: ~0.15ms average
• EdDSA operations: ~0.3ms round-trip
• Memory usage: <7MB for 1000 operations

Complete Example

ESM (ECMAScript Modules)

import {
    generateRequestToken,
    verifyRequestToken,
    generateIssuanceToken,
    verifyIssuanceToken,
    generatePresentationToken,
    verifyPresentationToken,
    type KeyResolver,
} from '@hellocoop/web-identity'

// 1. Browser generates RequestToken
const requestToken = await generateRequestToken(
    {
        aud: 'issuer.example',
        nonce: 'rp-nonce-123',
        email: '[email protected]',
    },
    browserPrivateKey,
)

// 2. Issuer verifies RequestToken
const requestPayload = await verifyRequestToken(requestToken)

// 3. Issuer generates IssuanceToken
const issuanceToken = await generateIssuanceToken(
    {
        iss: 'issuer.example',
        cnf: { jwk: extractedBrowserPublicKey },
        email: requestPayload.email,
        email_verified: true,
    },
    issuerPrivateKey,
)

// 4. Browser verifies IssuanceToken
const keyResolver: KeyResolver = async (kid, issuer) => {
    return await getIssuerPublicKey(kid, issuer)
}

const issuancePayload = await verifyIssuanceToken(issuanceToken, keyResolver)

// 5. Browser generates PresentationToken
const presentationToken = await generatePresentationToken(
    issuanceToken,
    'https://rp.example',
    'rp-nonce-123',
    browserPrivateKey,
)

// 6. Relying Party verifies PresentationToken (automatic DNS discovery)
const presentationPayload = await verifyPresentationToken(
    presentationToken,
    'https://rp.example',
    'rp-nonce-123',
)

console.log('Verified email:', presentationPayload.sdJwt.email)

CommonJS

const {
    generateRequestToken,
    verifyRequestToken,
    generateIssuanceToken,
    verifyIssuanceToken,
    generatePresentationToken,
    verifyPresentationToken,
} = require('@hellocoop/web-identity')

// Key resolver function
const keyResolver = async (kid, issuer) => {
    return await getIssuerPublicKey(kid, issuer)
}

// Same usage as ESM example above...
// (The rest of the implementation is identical)

Specification

This package implements the Verified Email Autocomplete protocol. For detailed protocol information, please refer to the specification.

Contributing

This package is part of the Hello Identity Co-op packages monorepo. Issues and contributions are welcome.