Support CA fingerprint validation (#1499)

Co-authored-by: Aleh Zasypkin <aleh.zasypkin@gmail.com>
Co-authored-by: Ioannis Kakavas <ioannis@elastic.co>

test/utils/buildServer.js

@@ -19,6 +19,7 @@
 
 'use strict'
 
+const crypto = require('crypto')
 const debug = require('debug')('elasticsearch-test')
 const stoppable = require('stoppable')
 
@@ -35,6 +36,13 @@ const secureOpts = {
   cert: readFileSync(join(__dirname, '..', 'fixtures', 'https.cert'), 'utf8')
 }
 
+const caFingerprint = getFingerprint(secureOpts.cert
+  .split('\n')
+  .slice(1, -1)
+  .map(line => line.trim())
+  .join('')
+)
+
 let id = 0
 function buildServer (handler, opts, cb) {
   const serverId = id++
@@ -58,7 +66,7 @@ function buildServer (handler, opts, cb) {
       server.listen(0, () => {
         const port = server.address().port
         debug(`Server '${serverId}' booted on port ${port}`)
-        resolve([Object.assign({}, secureOpts, { port }), server])
+        resolve([Object.assign({}, secureOpts, { port, caFingerprint }), server])
       })
     })
   } else {
@@ -70,4 +78,11 @@ function buildServer (handler, opts, cb) {
   }
 }
 
+function getFingerprint (content, inputEncoding = 'base64', outputEncoding = 'hex') {
+  const shasum = crypto.createHash('sha256')
+  shasum.update(content, inputEncoding)
+  const res = shasum.digest(outputEncoding)
+  return res.toUpperCase().match(/.{1,2}/g).join(':')
+}
+
 module.exports = buildServer