/// <summary>
/// Sign a file using keyed hash.
/// </summary>
/// <param name="hashType">Hash type.</param>
/// <param name="key">Key</param>
/// <param name="sourceFilePath">Source file path.</param>
public static byte[] Sign(ZKeyedHashAlgorithmType hashType, byte[] key, byte[] source)
{
#region Check inputs.
if (key == null)
{
throw new ArgumentNullException(LL.ZKeyedHashGenie_ArgumentNullException_Key);
}
if (source == null)
{
throw new ArgumentNullException(LL.ZKeyedHashGenie_ArgumentNullException_Source);
}
#endregion Check inputs.
using (var hmac = new ZKeyedHash(hashType, key))
{
// Write hash value to signed file header.
var hashValue = hmac.ComputeHash(inputStream);
inputStream.Position = 0;
outputStream.Write(hashValue, 0, hashValue.Length);
// Write source file contents to signed file.
int bytesRead;
var buffer = new byte[KReadByteLength];
do
{
bytesRead = inputStream.Read(buffer, 0, KReadByteLength);
outputStream.Write(buffer, 0, bytesRead);
} while (bytesRead > 0);
}
}
/// <summary>
/// Verify if the key stored in the source file matches the content hash.
/// </summary>
/// <param name="hashType">Hash type.</param>
/// <param name="key">Key</param>
/// <param name="sourceFilePath">Source file path.</param>
/// <returns>Whether hash matches the content.</returns>
public static bool Verify(ZKeyedHashAlgorithmType hashType, byte[] key, string sourceFilePath)
{
#region Check inputs.
if (key == null)
{
throw new ArgumentNullException(LL.ZKeyedHashGenie_ArgumentNullException_Key);
}
if (File.Exists(sourceFilePath))
{
throw new FileNotFoundException(LL.ZKeyedHashGenie_FileNotFoundException_SourceFilePath);
}
#endregion Check inputs.
using (var hmac = new ZKeyedHash(hashType, key))
{
var storedHash = new byte[hmac.HashSize / 8];
using (var inputStream = new FileStream(sourceFilePath, FileMode.Open))
{
inputStream.Read(storedHash, 0, storedHash.Length);
var computedHash = hmac.ComputeHash(inputStream);
if (storedHash.Where((t, i) => computedHash[i] != t).Any())
{
return(false);
}
}
}
return(true);
}
/// <summary>
/// Sign a file using keyed hash.
/// </summary>
/// <param name="hashType">Hash type.</param>
/// <param name="key">Key</param>
/// <param name="sourceFilePath">Source file path.</param>
/// <param name="signedFilePath">Signed file path.</param>
public static void Sign(ZKeyedHashAlgorithmType hashType, byte[] key, string sourceFilePath, string signedFilePath)
{
#region Check inputs.
if (key == null)
{
throw new ArgumentNullException(LL.ZKeyedHashGenie_ArgumentNullException_Key);
}
if (File.Exists(sourceFilePath))
{
throw new FileNotFoundException(LL.ZKeyedHashGenie_FileNotFoundException_SourceFilePath);
}
#endregion Check inputs.
using (var hmac = new ZKeyedHash(hashType, key))
{
using (var inputStream = new FileStream(sourceFilePath, FileMode.Open))
{
using (var outputStream = new FileStream(signedFilePath, FileMode.Create))
{
// Write hash value to signed file header.
var hashValue = hmac.ComputeHash(inputStream);
inputStream.Position = 0;
outputStream.Write(hashValue, 0, hashValue.Length);
// Write source file contents to signed file.
int bytesRead;
var buffer = new byte[KReadByteLength];
do
{
bytesRead = inputStream.Read(buffer, 0, KReadByteLength);
outputStream.Write(buffer, 0, bytesRead);
} while (bytesRead > 0);
}
}
}
}
