public void send_a_message_with_digital_signature_expect_intercepted_message_as_invalid()
{
// User generates a message, hashes the message and signs it with their PRIVATE key //
var message = Encoding.UTF8.GetBytes("This is a message that will be changed after the digital signature.");
// User sends the message //
byte[] hashedMessage = Hashing.ComputeHashSha256(message);
// Receiver calculates the hash of the encrypted data //
var digitalSignature = new DigitalSignature();
digitalSignature.AssignNewKey();
// this signature is sent along with the message ? //
var signature = digitalSignature.SignData(hashedMessage);
// Message intercepted and altered //
message = Encoding.UTF8.GetBytes("This is a message that was intercepted after the signature.");
hashedMessage = Hashing.ComputeHashSha256(message);
// Receiver verifies the digital signature using the public key //
var verified = digitalSignature.VerifySignature(hashedMessage, signature);
// the message should be verified at this point//
Assert.IsFalse(verified);
}
public void SaveAndLoadKeys()
{
var ds = new DigitalSignature();
ds.AssignNewKey();
ds.SavePublicKey(out var exponent1, out var modulus1);
ds.SavePrivateKey(out var exponent2, out var modulus2, out var p, out var q, out var dp, out var dq, out var inverseQ, out var d);
var signature1 = ds.SignData(_hash);
var result1 = ds.VerifySignature(_hash, signature1);
Assert.IsTrue(result1);
var sut = new DigitalSignature();
sut.LoadPublicKey(exponent1, modulus1);
sut.LoadPrivateKey(exponent2, modulus2, p, q, dp, dq, inverseQ, d);
var signature2 = ds.SignData(_hash);
var result2 = ds.VerifySignature(_hash, signature2);
Assert.IsTrue(result2);
Assert.AreEqual(signature1, signature2);
}
public void HashAlgorithmTests(int keySize, string hashAlgorithm)
{
var ds = new DigitalSignature(keySize, hashAlgorithm);
ds.AssignNewKey();
byte[] hash;
switch (hashAlgorithm)
{
case "SHA1":
hash = Hash.Create(HashType.SHA1, "Hello world", string.Empty);
break;
case "SHA256":
hash = Hash.Create(HashType.SHA256, "Hello world", string.Empty);
break;
case "SHA384":
hash = Hash.Create(HashType.SHA384, "Hello world", string.Empty);
break;
case "SHA512":
hash = Hash.Create(HashType.SHA512, "Hello world", string.Empty);
break;
default:
throw new ArgumentException("hashAlgorithm");
}
var signature = ds.SignData(hash);
var result = ds.VerifySignature(hash, signature);
Assert.IsTrue(result);
}
public Form4()
{
InitializeComponent();
rsa.AssignNewKey();
string subKey = @"SOFTWARE\Microsoft\Windows NT\CurrentVersion";
RegistryKey key = Microsoft.Win32.Registry.LocalMachine;
RegistryKey skey = key.OpenSubKey(subKey);
string name = skey.GetValue("ProductName").ToString();
string releaseId = skey.GetValue("ReleaseId").ToString();
lb_osInfo.Text = name + " " + releaseId + (Environment.Is64BitOperatingSystem ? " 64-bit" : " 32-bit");
if (File.Exists("data.blc"))
{
chain.LoadFile("data.blc");
for (int i = 0; i < chain.Blocks.Count; i++)
{
nBlock++;
cb_blockList.Items.Add("Block " + (i + 1).ToString());
}
lb_blockName.Text = "Block " + (nBlock + 1).ToString();
cb_blockList.SelectedIndex = cb_blockList.Items.Count - 1;
cacheBlock = new Block(nBlock);
}
}
//[TestCase(8192)] // Slow
//[TestCase(16384)] // Very slow
public void KeySizeTests(int keySize)
{
var ds = new DigitalSignature(keySize, "SHA256");
ds.AssignNewKey();
var signature = ds.SignData(_hash);
var result = ds.VerifySignature(_hash, signature);
Assert.IsTrue(result);
}
public void SavedPublicAndPrivateKeysMatch()
{
var ds = new DigitalSignature();
ds.AssignNewKey();
ds.SavePublicKey(out var exponent1, out var modulus1);
ds.SavePrivateKey(out var exponent2, out var modulus2, out var p, out var q, out var dp, out var dq, out var inverseQ, out var d);
Assert.AreEqual(exponent1, exponent2);
Assert.AreEqual(modulus1, modulus2);
}
public static string HashDocumentAndSignData(ref DigitalSignature newDigSig, string document)
{
byte[] hashedDocument = newDigSig.HashDocument(Encoding.UTF8.GetBytes(document));
newDigSig.AssignNewKey();
var signature = newDigSig.SignData(hashedDocument);
DocumentAndSignature = new StoredDocumentAndSignature {
Document = document, HashedDocument = hashedDocument, Signature = signature
};
return("Document er hashed og signed");
}
public Form1()
{
InitializeComponent();
rsa.AssignNewKey();
if (File.Exists("Blockchain.txt"))
{
chain.LoadFile("Blockchain.txt");
for (int i = 0; i < chain.Blocks.Count; i++)
{
nBlock++;
cb_blockList.Items.Add("Block " + (i + 1).ToString());
}
txt_nameBlock.Text = "Block " + (nBlock + 1).ToString();
cb_blockList.SelectedIndex = cb_blockList.Items.Count - 1;
cacheBlock = new Block(nBlock);
}
}
public void send_a_message_with_digital_signature_expect_message_validation()
{
// User generates a message, hashes the message and signs it with their PRIVATE key //
var message = Encoding.UTF8.GetBytes("This is a message that will be verified through digital signature.");
// User sends the message //
byte[] hashedMessage = Hashing.ComputeHashSha256(message);
// Receiver calculates the hash of the encrypted data //
var digitalSignature = new DigitalSignature();
digitalSignature.AssignNewKey();
// Receiver verifies the digital signature using the public key //
var signature = digitalSignature.SignData(hashedMessage);
var verified = digitalSignature.VerifySignature(hashedMessage, signature);
// the message should be verified at this point//
Assert.IsTrue(verified);
}
public KeyStore(byte[] authenticatedHashKey)
{
AuthenticatedHashKey = authenticatedHashKey;
DigitalSignature = new DigitalSignature();
DigitalSignature.AssignNewKey();
}
public HybridEncryption()
{
_aes = new AesEncryption();
_digitalSignature = new DigitalSignature();
_digitalSignature.AssignNewKey();
}
static void Main()
{
//const string original = "Very secret and important information that can not fall into the wrong hands.";
//string original = new String('0', 127);
string original = "abcdefghijklmnopqrstuvwxyz1234567890abcdefghijklmnopqrstuvwxyz1234567890abcdefghijklmnopqrstuvwxyz1234567890abcdefghijklmnopqrs";
original = GenerateRandomText();
//string original = "abcdefghijklmnopqrstuvwxyz1234567890abcdefghijklmnopqrstuvwxyz1234567890abcdefghijklmnopqrstuvwxyz1234567890abcdefghijklmnopqrstuvwxyz1234567890";
//string original = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam non dictum diam. Donec feugiat libero sed arcu interdum consectetur vitae amet.";
//string original = @"?=??Y@쳘?{?? &긳 ? v ? ";
var hybrid = new HybridEncryption();
var rsaParams = new RSAWithRSAParameterKey();
rsaParams.ImportKeys();
var digitalSignature = new DigitalSignature();
digitalSignature.AssignNewKey();
Console.WriteLine("Hybrid Encryption with Integrity Check Demonstration in .NET");
Console.WriteLine("------------------------------------------------------------");
Console.WriteLine();
try
{
var originalData = Encoding.UTF8.GetBytes(original);
byte[] compressedBytes = Compress(originalData);
byte[] decompressedBytes = Decompress(compressedBytes);
var encryptedBlock = hybrid.EncryptData(
originalData, rsaParams, digitalSignature);
var decrpyted = hybrid.DecryptData(encryptedBlock, rsaParams, digitalSignature);
//byte[] gzippedBytes = GetGZippedBytes(encryptedBlock.EncryptedData);
//byte[] ungzippedBytes = GetUnGZippedBytes(gzippedBytes);
byte[] gzippedBytes = Compress(encryptedBlock.EncryptedData);
byte[] ungzippedBytes = Decompress(gzippedBytes);
Console.WriteLine("Original Message = " + original);
Console.WriteLine("Original Message Length: {0}", original.Length);
Console.WriteLine("Compressed Original Message = " + Convert.ToBase64String(compressedBytes));
Console.WriteLine("Compressed Original Message Length: {0}", compressedBytes.Length);
Console.WriteLine("DeCompressed Original Message = " + Convert.ToBase64String(decompressedBytes));
Console.WriteLine("DeCompressed Original Message Length: {0}", decompressedBytes.Length);
Console.WriteLine("Encrypted Data: {0}", Convert.ToBase64String(encryptedBlock.EncryptedData));
Console.WriteLine("Encrypted Data Size: {0}", encryptedBlock.EncryptedData.Length);
Console.WriteLine("GZipped Encrypted Data: {0}", Convert.ToBase64String(gzippedBytes));
Console.WriteLine("GZipped Encrypted Data Size: {0}", gzippedBytes.Length);
Console.WriteLine("UnGZipped Encrypted Data: {0}", Convert.ToBase64String(ungzippedBytes));
Console.WriteLine("UnGZipped Encrypted Data Size: {0}", ungzippedBytes.Length);
Console.WriteLine();
Console.WriteLine("Message After Decryption = " + Encoding.UTF8.GetString(decrpyted));
}
catch (CryptographicException ex)
{
Console.WriteLine("Error : " + ex.Message);
}
Console.ReadLine();
}
