added ability to verify one's secret key

election_urls.py

@@ -26,6 +26,7 @@
     (r'^/trustees/(?P<trustee_uuid>[^/]+)/home$', trustee_home),
     (r'^/trustees/(?P<trustee_uuid>[^/]+)/sendurl$', trustee_send_url),
     (r'^/trustees/(?P<trustee_uuid>[^/]+)/keygenerator$', trustee_keygenerator),
+    (r'^/trustees/(?P<trustee_uuid>[^/]+)/check-sk$', trustee_check_sk),
     (r'^/trustees/(?P<trustee_uuid>[^/]+)/upoad-pk$', trustee_upload_pk),
     (r'^/trustees/(?P<trustee_uuid>[^/]+)/decrypt-and-prove$', trustee_decrypt_and_prove),
     (r'^/trustees/(?P<trustee_uuid>[^/]+)/upload-decryption$', trustee_upload_decryption),

templates/trustee_check_sk.html

@@ -0,0 +1,78 @@
+{% extends "helios/templates/cryptobase.html" %}
+
+{% block content %}
+<script>
+function reset() {
+    $('#processing').hide();
+    $('#result').html("");
+    $('#input').hide();
+    $('#loading').show();
+    BigInt.setup(function() {
+        $('#loading').hide();
+        $('#input').show();
+    });
+}
+
+$(document).ready(function() {
+    reset();
+});
+
+var PK_HASH = "{{trustee.public_key_hash}}";
+
+function check_sk(sk_value) {
+    $('#input').hide();
+    $('#processing').show();
+
+    try {
+      var secret_key = ElGamal.SecretKey.fromJSONObject(jQuery.secureEvalJSON(sk_value));
+
+      var pk_hash = b64_sha256(jQuery.toJSON(secret_key.pk));
+      var key_ok_p = (pk_hash == PK_HASH);
+    } catch (e) {
+      debugger;
+      var key_ok_p = false;
+    }
+
+    $('#processing').hide();
+
+    var reset_link = "<br /><a href='javascript:reset();'>try again</a>";
+    if (key_ok_p) {
+      $('#result').html("your secret key matches!");
+    } else {
+      $('#result').html("OH OH, your key is bad." + reset_link);
+    }
+}
+</script>
+  <h2 class="title">{{election.name}} &mdash; Trustee {{trustee.name}} &mdash; Check Secret Key</span></h2>
+
+<p>
+Your public key fingerprint is: <b>{{trustee.public_key_hash}}</b>
+</p>
+
+<div id="loading">
+loading crypto functions...
+</div>
+
+<div id="input" style="display:none;">
+<p>
+To verify that you have the right secret key, paste it here:
+<p>
+
+<form onsubmit="check_sk(this.secret_key.value); return false;">
+<textarea name="secret_key" cols="60" rows ="5" wrap="soft">
+</textarea>
+<br />
+<input type="submit" value="check" />
+</form>
+</div>
+
+<div id="processing" style="display:none;">
+checking your secret key...
+</div>
+
+<div id="result">
+</div>
+
+
+<div id="applet_div"></div>
+{% endblock %}

templates/trustee_home.html

@@ -6,7 +6,8 @@ <h2 class="title">{{election.name}} &mdash; Trustee {{trustee.name}} Home</span>
 <p>
 {% if trustee.public_key_hash %}
 You have successfully uploaded your public key.<br />
-Your public key fingerprint is: <b>{{trustee.public_key_hash}}</b>
+Your public key fingerprint is: <b>{{trustee.public_key_hash}}</b>.<br />
+You can <a href="{% url helios.views.trustee_check_sk election.uuid, trustee.uuid %}">verify that you have the right secret key</a>.
 {% else %}
 <a href="{% url helios.views.trustee_keygenerator election.uuid, trustee.uuid %}">setup your key</a>
 {% endif %}

views.py

@@ -292,6 +292,10 @@ def trustee_send_url(request, election, trustee_uuid):
 def trustee_home(request, election, trustee):
   return render_template(request, 'trustee_home', {'election': election, 'trustee':trustee})
 
+@trustee_check
+def trustee_check_sk(request, election, trustee):
+  return render_template(request, 'trustee_check_sk', {'election': election, 'trustee':trustee})
+
 @trustee_check
 def trustee_upload_pk(request, election, trustee):
   if request.method == "POST":