public bool Confirm(string plainText, string hashValue, SupportedHash hash)
{
byte[] hashBytes = Convert.FromBase64String(hashValue);
int hashSize = 0;
switch (hash)
{
case SupportedHash.SHA256:
hashSize = 32;
break;
case SupportedHash.SHA384:
hashSize = 48;
break;
case SupportedHash.SHA512:
hashSize = 64;
break;
}
byte[] saltBytes = new byte[hashBytes.Length - hashSize];
for (int x = 0; x < saltBytes.Length; x++)
{
saltBytes[x] = hashBytes[hashSize + x];
}
string newHash = ComputeHash(plainText, hash, saltBytes);
return(hashValue == newHash);
}
public string ComputeHash(string plainText, SupportedHash hash, byte[] salt)
{
byte[] plainData = Encoding.UTF8.GetBytes(plainText);
byte[] plainDataWithSalt = new byte[plainData.Length + salt.Length];
for (int x = 0; x < plainData.Length; x++)
{
plainDataWithSalt[x] = plainData[x];
}
for (int n = 0; n < salt.Length; n++)
{
plainDataWithSalt[plainData.Length + n] = salt[n];
}
byte[] hashValue = null;
switch (hash)
{
case SupportedHash.SHA256:
SHA256Managed sha = new SHA256Managed();
hashValue = sha.ComputeHash(plainDataWithSalt);
sha.Dispose();
break;
case SupportedHash.SHA384:
SHA384Managed sha1 = new SHA384Managed();
hashValue = sha1.ComputeHash(plainDataWithSalt);
sha1.Dispose();
break;
case SupportedHash.SHA512:
SHA512Managed sha2 = new SHA512Managed();
hashValue = sha2.ComputeHash(plainDataWithSalt);
sha2.Dispose();
break;
}
byte[] result = new byte[hashValue.Length + salt.Length];
for (int x = 0; x < hashValue.Length; x++)
{
result[x] = hashValue[x];
}
for (int n = 0; n < salt.Length; n++)
{
result[hashValue.Length + n] = salt[n];
}
return(Convert.ToBase64String(result));
}
public string ComputeHash(string plainText, SupportedHash hash)
{
int minSaltLength = 4, maxSaltLength = 16;
Random r = new Random();
int saltLength = r.Next(minSaltLength, maxSaltLength);
byte[] saltBytes = new byte[saltLength];
using (var rng = new RNGCryptoServiceProvider())
rng.GetNonZeroBytes(saltBytes);
byte[] plainData = Encoding.UTF8.GetBytes(plainText);
byte[] plainDataWithSalt = new byte[plainData.Length + saltBytes.Length];
for (int x = 0; x < plainData.Length; x++)
{
plainDataWithSalt[x] = plainData[x];
}
for (int n = 0; n < saltBytes.Length; n++)
{
plainDataWithSalt[plainData.Length + n] = saltBytes[n];
}
byte[] hashValue = null;
switch (hash)
{
case SupportedHash.SHA256:
SHA256Managed sha = new SHA256Managed();
hashValue = sha.ComputeHash(plainDataWithSalt);
sha.Dispose();
break;
case SupportedHash.SHA384:
SHA384Managed sha1 = new SHA384Managed();
hashValue = sha1.ComputeHash(plainDataWithSalt);
sha1.Dispose();
break;
case SupportedHash.SHA512:
SHA512Managed sha2 = new SHA512Managed();
hashValue = sha2.ComputeHash(plainDataWithSalt);
sha2.Dispose();
break;
}
byte[] result = new byte[hashValue.Length + saltBytes.Length];
for (int x = 0; x < hashValue.Length; x++)
{
result[x] = hashValue[x];
}
for (int n = 0; n < saltBytes.Length; n++)
{
result[hashValue.Length + n] = saltBytes[n];
}
return(Convert.ToBase64String(result));
}
