void ComputeHash(out AsymmetricAlgorithm privateKey, out SignatureDescription description, out HashAlgorithm hash)
{
privateKey = this.Certificate.PrivateKey;
description = CryptoConfig.CreateFromName(this.SHA1SignatureName) as SignatureDescription;
if (description == null)
{
throw new CompactSignatureSecurityException(string.Format(
CultureInfo.CurrentCulture,
"Error creating SignatureDescription from the signature name {0}",
this.SHA1SignatureName));
}
hash = description.CreateDigest();
if (hash == null)
{
throw new CompactSignatureSecurityException(string.Format(
CultureInfo.CurrentCulture,
"Error creating HashAlgorithm from the signature name {0}",
this.SHA1SignatureName));
}
HashStream hashStream = this.TakeHashStream(hash);
// Create the references
StringBuilder sb = new StringBuilder();
if (!String.IsNullOrEmpty(this.InclusivePrefixesList))
{
for (int i = 0; i < this.references.Count; i++)
{
sb.Append(string.Format(SignatureProcessor.ExtendedSignatureReferenceWithPrefixes,
this.references[i].Id,
this.InclusivePrefixesList,
Convert.ToBase64String(this.references[i].Digest)));
}
}
else
{
for (int i = 0; i < this.references.Count; i++)
{
sb.Append(string.Format(SignatureProcessor.ExtendedSignatureReferenceNoPrefixes,
this.references[i].Id,
Convert.ToBase64String(this.references[i].Digest)));
}
}
string expandedSignature = string.Format(
ExpandedSignatureScheleton,
// Replace the references
sb.ToString());
byte[] bytes = Encoding.UTF8.GetBytes(expandedSignature);
hashStream.Write(bytes, 0, bytes.Length);
hashStream.FlushHash();
}
