Use buffers for BIMI docs

lib/bimi-handler.js

@@ -5,6 +5,7 @@ const https = require('https');
 const { validateSvg } = require('mailauth/lib/bimi/validate-svg');
 const { vmc } = require('@postalsys/vmc');
 const { formatDomain, getAlignment } = require('mailauth/lib/tools');
+const crypto = require('crypto');
 
 class BimiHandler {
     static create(options = {}) {
@@ -115,6 +116,10 @@ class BimiHandler {
                 throw error;
             }
 
+            if (bimiDocument?.content?.buffer) {
+                bimiDocument.content = bimiDocument.content.buffer;
+            }
+
             return bimiDocument;
         }
 
@@ -283,6 +288,12 @@ class BimiHandler {
             { upsert: true, returnDocument: 'after' }
         );
 
+        bimiDocument = r?.value;
+
+        if (bimiDocument?.content?.buffer) {
+            bimiDocument.content = bimiDocument.content.buffer;
+        }
+
         return r && r.value;
     }
 
@@ -337,6 +348,28 @@ class BimiHandler {
                 throw error;
             }
 
+            if (locationStatus === 'fulfilled' && locationValue?.content && authorityValue.vmc?.hashAlgo && authorityValue.vmc?.validHash) {
+                console.log(locationValue.content);
+                let hash = crypto
+                    .createHash(authorityValue.vmc.hashAlgo)
+                    //sss
+                    .update(locationValue.content)
+                    .digest('hex');
+                if (hash === authorityValue.vmc.hashValue) {
+                    // logo files match, so location URL is safe to use
+                    authorityValue.locationUrl = bimiData.location;
+                } else {
+                    let error = new Error('Logo files from l= and a= do not match');
+                    error.details = {
+                        locationHash: hash,
+                        authorityHash: authorityValue.vmc.hashValue,
+                        hashAlgo: authorityValue.vmc.hashAlgo
+                    };
+                    error.code = 'LOGO_HASH_MISMATCH';
+                    throw error;
+                }
+            }
+
             return authorityValue;
         }
 
@@ -348,7 +381,6 @@ module.exports = BimiHandler;
 
 /*
 const db = require('./db');
-
 db.connect(() => {
     let bimi = BimiHandler.create({
         database: db.database