From 4aaf25b705391e6cad24de37946f1741afa21042 Mon Sep 17 00:00:00 2001
From: Yarmo Mackenbach <yarmo@yarmo.eu>
Date: Fri, 16 Apr 2021 13:13:06 +0200
Subject: [PATCH] Add verification module

---
 src/index.js         |   2 +
 src/verifications.js | 115 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 117 insertions(+)
 create mode 100644 src/verifications.js

diff --git a/src/index.js b/src/index.js
index 6bb2e68..00ac2d2 100644
--- a/src/index.js
+++ b/src/index.js
@@ -15,6 +15,7 @@ limitations under the License.
 */
 const Claim = require('./claim')
 const proofs = require('./proofs')
+const verification = require('./verification')
 const keys = require('./keys')
 const signatures = require('./signatures')
 const enums = require('./enums')
@@ -23,6 +24,7 @@ const utils = require('./utils')
 
 exports.Claim = Claim
 exports.proofs = proofs
+exports.verification = verification
 exports.keys = keys
 exports.signatures = signatures
 exports.enums = enums
diff --git a/src/verifications.js b/src/verifications.js
new file mode 100644
index 0000000..2d582bf
--- /dev/null
+++ b/src/verifications.js
@@ -0,0 +1,115 @@
+/*
+Copyright 2021 Yarmo Mackenbach
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+const utils = require('./utils')
+const E = require('./enums')
+
+const runJSON = (
+  proofData,
+  checkPath,
+  checkClaim,
+  checkRelation
+) => {
+  let re
+
+  if (!proofData) {
+    return false
+  }
+
+  if (Array.isArray(proofData)) {
+    let result = false
+    proofData.forEach((item, i) => {
+      if (result) { return }
+      result = runJSON(item, checkPath, checkClaim, checkRelation)
+    })
+    return result
+  }
+
+  if (checkPath.length == 0) {
+    switch (checkRelation) {
+      default:
+      case E.ClaimRelation.CONTAINS:
+        re = new RegExp(checkClaim, 'gi')
+        return re.test(proofData.replace(/\r?\n|\r|\\/g, ''))
+        break
+
+      case E.ClaimRelation.EQUALS:
+        return proofData.replace(/\r?\n|\r|\\/g, '').toLowerCase() ==
+          checkClaim.toLowerCase()
+        break
+
+      case E.ClaimRelation.ONEOF:
+        re = new RegExp(checkClaim, 'gi')
+        return re.test(proofData.join('|'))
+        break
+    }
+  }
+
+  try {
+    checkPath[0] in proofData
+  } catch (e) {
+    throw new Error('err_json_structure_incorrect')
+  }
+
+  return runJSON(
+    proofData[checkPath[0]],
+    checkPath.slice(1),
+    checkClaim,
+    checkRelation
+  )
+}
+
+const run = (proofData, claimData, fingerprint) => {
+  let res = {
+    result: false,
+    completed: false,
+    errors: [],
+  }
+  
+  switch (claimData.proof.request.format) {
+    case E.ProofFormat.JSON:
+      try {
+        res.result = runJSON(
+          proofData,
+          claimData.claim.path,
+          utils.generateClaim(fingerprint, claimData.claim.format),
+          claimData.claim.relation
+        )
+        res.completed = true
+      } catch (error) {
+        res.errors.push(error.message ? error.message : error)
+      }
+      break
+    case E.ProofFormat.TEXT:
+      try {
+        const re = new RegExp(
+          utils
+            .generateClaim(fingerprint, claimData.claim.format)
+            .replace('[', '\\[')
+            .replace(']', '\\]'),
+          'gi'
+        )
+        res.result = re.test(proofData.replace(/\r?\n|\r/, ''))
+        res.completed = true
+      } catch (error) {
+        res.errors.push('err_unknown_text_verification')
+      }
+      break
+  }
+
+  return res
+}
+
+exports.run = run
\ No newline at end of file