Fix a bug that caused the generation of safe primes to fail

FabioTacke · Jun 5, 2017 · 3eb1659 · 3eb1659
1 parent 395f3c1
commit 3eb1659
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Showing 3 changed files with 5 additions and 2 deletions.
diff --git 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
@@ -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
@@ -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