From 3eb16594d1cd569e1ba69d0ec083bdecb5e550f9 Mon Sep 17 00:00:00 2001
From: Fabio Tacke <tackefab@informatik.hu-berlin.de>
Date: Mon, 5 Jun 2017 14:06:10 +0200
Subject: [PATCH] Fix a bug that caused the generation of safe primes to fail

---
 PVSS.podspec                   | 2 +-
 Sources/PVSSInstance.swift     | 3 +++
 Tests/PVSSTests/PVSSTest.swift | 2 +-
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/PVSS.podspec b/PVSS.podspec
index 0c61308..f469c16 100644
--- a/PVSS.podspec
+++ b/PVSS.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name             = 'PVSS'
-  s.version          = '1.0.4'
+  s.version          = '1.0.5'
   s.summary          = 'An implementation of Publicly Verifiably Secret Sharing (PVSS) in Swift.'
   s.description      = <<-DESC
 The library implements a PVSS scheme in Swift. The algorithm is based on "A Simple Publicly Verifiable Secret Sharing Scheme and its Application to Electronic Voting" by Berry Schoenmakers.
diff --git a/Sources/PVSSInstance.swift b/Sources/PVSSInstance.swift
index 4d1d3e8..ed39104 100644
--- a/Sources/PVSSInstance.swift
+++ b/Sources/PVSSInstance.swift
@@ -30,6 +30,9 @@ public struct PVSSInstance {
   public init(length: Int) {
     // Find safe prime
     var q = BigUInt.randomInteger(withExactWidth: length)
+    if q % 2 == 0 {
+      q -= 1
+    }
     var sophieGermainCandidate: BigUInt
     
     repeat {
diff --git a/Tests/PVSSTests/PVSSTest.swift b/Tests/PVSSTests/PVSSTest.swift
index 95e8b3c..f5cd813 100644
--- a/Tests/PVSSTests/PVSSTest.swift
+++ b/Tests/PVSSTests/PVSSTest.swift
@@ -137,7 +137,7 @@ class PVSSTest: XCTestCase {
     let secret = BigUInt(secretMessage.data(using: .utf8)!)
     
     // Create default PVSS Instance for the dealer
-    let pvssInstance = PVSSInstance()
+    let pvssInstance = PVSSInstance(length: 128)
     let dealer = Participant(pvssInstance: pvssInstance)
     
     // Participants p1, p2 and p3