From ff41f06dbb55c11d6f190ed0d5885c3db6104089 Mon Sep 17 00:00:00 2001
From: Berend Sliedrecht <61358536+berendsliedrecht@users.noreply.github.com>
Date: Fri, 31 Jan 2025 12:18:38 +0100
Subject: [PATCH] chore: add better age_over_NN attributes (#46)

Signed-off-by: Berend Sliedrecht <berend@animo.id>
---
 .changeset/tiny-chefs-drum.md               |  5 ++++
 src/__tests__/issuing/issuing-mdoc.tests.ts |  8 ++++---
 src/mdoc/model/document.ts                  | 26 +++++++++++++++++++--
 3 files changed, 34 insertions(+), 5 deletions(-)
 create mode 100644 .changeset/tiny-chefs-drum.md

diff --git a/.changeset/tiny-chefs-drum.md b/.changeset/tiny-chefs-drum.md
new file mode 100644
index 0000000..f45ba2c
--- /dev/null
+++ b/.changeset/tiny-chefs-drum.md
@@ -0,0 +1,5 @@
+---
+"@animo-id/mdoc": patch
+---
+
+Include different age*over_NN values and exclude age_over*<CURRENT_AGE>
diff --git a/src/__tests__/issuing/issuing-mdoc.tests.ts b/src/__tests__/issuing/issuing-mdoc.tests.ts
index d41e889..af2f788 100644
--- a/src/__tests__/issuing/issuing-mdoc.tests.ts
+++ b/src/__tests__/issuing/issuing-mdoc.tests.ts
@@ -103,15 +103,17 @@ describe('issuing an MDOC', () => {
 
   it('should include the namespace and attributes', () => {
     const attrValues = parsedDocument.getIssuerNameSpace('org.iso.18013.5.1')
-    // @ts-expect error this will work
-    const currentAge = new Date(Date.now() - new Date('2007-03-25').getTime()).getFullYear() - 1970
     expect(attrValues).toMatchInlineSnapshot(`
       Map {
         "family_name" => "Jones",
         "given_name" => "Ava",
         "birth_date" => "2007-03-25",
+        "age_over_12" => true,
+        "age_over_14" => true,
+        "age_over_16" => true,
+        "age_over_18" => false,
         "age_over_21" => false,
-        "age_over_17" => true,
+        "age_over_65" => false,
         "issue_date" => "2023-09-01",
         "expiry_date" => "2028-09-30",
         "issuing_country" => "US",
diff --git a/src/mdoc/model/document.ts b/src/mdoc/model/document.ts
index d4d13f5..99eb342 100644
--- a/src/mdoc/model/document.ts
+++ b/src/mdoc/model/document.ts
@@ -38,6 +38,17 @@ export default function isObject(input: unknown): input is Record<string, unknow
 
 const DEFAULT_NS = 'org.iso.18013.5.1'
 
+// TODO:
+//
+// This should be calculated from the `validFrom` field in device retrieval
+// and the `iat` from server retrieval. Not `Date.now()`
+//
+// In case of device retrieval, the value of an age_over_NN data element
+// shall be calculated by the issuing authority infrastructure to be valid
+// at the value of the timestamp in the validFrom element in the MSO
+// from 9.1.2.4. In case of server retrieval, the value of an age_over_NN
+// data element shall be valid at the value of the iat timestamp as
+// defined in 8.3.2.2.2.2 and 8.3.3.2.2.
 const getAgeInYears = (birth: string): number => {
   const birthDate = new Date(birth)
   birthDate.setHours(0, 0, 0, 0)
@@ -131,9 +142,20 @@ export class Document {
         if (typeof value !== 'string') {
           throw new Error(`Invalid type for 'birth_date'. Expected 'string', received '${typeof value}'`)
         }
+
         const ageInYears = getAgeInYears(value)
-        addAttribute('age_over_21', ageInYears >= 21)
-        addAttribute(`age_over_${Math.floor(ageInYears)}`, true)
+        const addAgePredicate = (predicate: number) => addAttribute(`age_over_${predicate}`, ageInYears >= predicate)
+
+        // Age predicates.
+        // Values defined in: https://bmi.usercontent.opencode.de/eudi-wallet/eidas-2.0-architekturkonzept/functions/00-pid-issuance-and-presentation/#pid-contents
+        // ISO/IEC 18013-5: 7.2.5 does not define which ages should be included.
+
+        addAgePredicate(12)
+        addAgePredicate(14)
+        addAgePredicate(16)
+        addAgePredicate(18)
+        addAgePredicate(21)
+        addAgePredicate(65)
       }
     }