Add a API call to the server:

rpc/settings: "action" = "list_ssl_checksums"
This will list the MD5 checksums of all the known SSL keys (in no particular order)

REST Request:
-------------------------------
PUT /rpc/settings
{
   "action" : "list_ssl_checksums"
}

WebSocket Request:
-------------------------------
{
   "args" : {
      "action" : "list_ssl_checksums"
   },
   "namespace" : "rpc",
   "name" : "settings",
   "id" : "fooid"
}

Response:
-------------------------------
{
  "args": {
    "md5_keys": [
      "0`H\u0013\r*\u00023\u000bc"
    ]
  },
  "id": "fooid",
  "name": "response",
  "namespace": "rpc"
}

src/server/AuthorizationManager.cpp

@@ -7,6 +7,8 @@
 
 #include "globals.h"
 
+#include <QCryptographicHash>
+
 // Stuff for PAM to work
 #include <sys/types.h>
 #include <security/pam_appl.h>
@@ -125,6 +127,22 @@ void AuthorizationManager::ListCertificates(QString token, QJsonObject *out){
   if(!user.isEmpty() && !username.isEmpty()){ out->insert(username, user); }
 }
 
+void AuthorizationManager::ListCertificateChecksums(QJsonObject *out){
+ QStringList keys; //Format: "RegisteredCerts/<user>/<key>"
+    //Read all user's certs (since we only need checksums)
+    keys = CONFIG->allKeys().filter("RegisteredCerts/");
+  keys.sort();
+  QJsonArray arr;
+  QCryptographicHash chash(QCryptographicHash::Md5);
+  for(int i=0; i<keys.length(); i++){
+    chash.addData( CONFIG->value(keys[i]).toString().toLocal8Bit() );
+    QByteArray res = chash.result();
+    chash.reset();
+    arr << QString(res);
+  }
+  out->insert("md5_keys", arr);
+}
+
 //Generic functions
 int AuthorizationManager::checkAuthTimeoutSecs(QString token){
 	//Return the number of seconds that a token is valid for