public void ComputeHashOnMultiBufferStream()
{
var firstArray = Encoding.ASCII.GetBytes("this is good");
var secondArray = Encoding.ASCII.GetBytes("this is bad");
using (var stream = new MultiBufferStream()) {
stream.AddBuffer(firstArray);
stream.AddBuffer(secondArray);
using (var sha256Hash = new SHA256Managed()) {
var hash = sha256Hash.ComputeHash(stream);
var hashString = HashToString(hash);
//Хеш для строки 'this is goodthis is bad', вычисленный с помощью внешней программы
var verifyHash = "B61A0664186896AF7D947E6A56DEB8D608FDF092E515DB531834FDE7DBFCAF79";
Assert.That(hashString, Is.EqualTo(verifyHash).IgnoreCase);
hashString = Convert.ToBase64String(hash);
var allStringHash = Convert.ToBase64String(sha256Hash.ComputeHash(Encoding.ASCII.GetBytes("this is goodthis is bad")));
Assert.That(hashString, Is.EqualTo(allStringHash).IgnoreCase);
}
}
}
public static string GetSHA256Hash(this Mime mime)
{
using (var stream = new MultiBufferStream()) {
if (!String.IsNullOrWhiteSpace(mime.MainEntity.Subject))
{
stream.AddBuffer(Encoding.ASCII.GetBytes(mime.MainEntity.Subject));
}
if (!String.IsNullOrWhiteSpace(mime.BodyText))
{
stream.AddBuffer(Encoding.ASCII.GetBytes(mime.BodyText));
}
if (String.IsNullOrWhiteSpace(mime.BodyText) && !String.IsNullOrWhiteSpace(mime.BodyHtml))
{
var convertedHtml = mime.HtmlToText();
if (!String.IsNullOrWhiteSpace(convertedHtml))
{
stream.AddBuffer(Encoding.ASCII.GetBytes(convertedHtml));
}
}
var attachments = mime.GetValidAttachements().OrderBy(m => m.GetFilename());
foreach (var attachment in attachments)
{
stream.AddBuffer(attachment.Data);
}
if (stream.Length > 0)
{
using (var sha256Hash = new SHA256Managed()) {
var hash = sha256Hash.ComputeHash(stream);
return(Convert.ToBase64String(hash));
}
}
return(String.Empty);
}
}
