public void Sign(IFileProvider fileProvider)
{
MemoryStream msManifestFile = new MemoryStream();
MemoryStream msSigFile = new MemoryStream();
byte[] keyBlock;
MemoryStream msSignatureFileBody = new MemoryStream();
try
{
//create the MF file header
using (StreamWriter swManifest = GetSW(msManifestFile))
{
swManifest.WriteLine("Manifest-Version: 1.0");
swManifest.WriteLine("Created-By: emulamer");
swManifest.WriteLine();
}
//so that we can do it in one pass, write the MF and SF line items at the same time to their respective streams
foreach (var infFile in fileProvider.FindFiles("*").Where(x => !x.StartsWith("META-INF")))
{
WriteEntryHashes(fileProvider, infFile, msManifestFile, msSignatureFileBody);
}
//compute the hash on the entirety of the manifest file for the SF file
msManifestFile.Seek(0, SeekOrigin.Begin);
var manifestFileHash = _sha.ComputeHash(msManifestFile);
//write the SF to memory then copy it out to the actual file- contents will be needed later to use for signing, don't want to hit the zip stream twice
byte[] sigFileBytes = null;
using (StreamWriter swSignatureFile = GetSW(msSigFile))
{
swSignatureFile.WriteLine("Signature-Version: 1.0");
swSignatureFile.WriteLine($"SHA1-Digest-Manifest: {Convert.ToBase64String(manifestFileHash)}");
swSignatureFile.WriteLine("Created-By: emulamer");
swSignatureFile.WriteLine();
}
msSignatureFileBody.Seek(0, SeekOrigin.Begin);
msSignatureFileBody.CopyTo(msSigFile);
msSigFile.Seek(0, SeekOrigin.Begin);
sigFileBytes = msSigFile.ToArray();
//get the key block (all the hassle distilled into one line), then write it out to the RSA file
keyBlock = SignIt(sigFileBytes);
//delete all the META-INF stuff that exists already
fileProvider.DeleteFiles("META-INF*");
//write the 3 files
msManifestFile.Seek(0, SeekOrigin.Begin);
fileProvider.Write("META-INF/MANIFEST.MF", msManifestFile.ToArray(), true, true);
fileProvider.Write("META-INF/BS.SF", sigFileBytes, true, true);
fileProvider.Write("META-INF/BS.RSA", keyBlock, true, true);
fileProvider.Save();
}
finally
{
if (msManifestFile != null)
{
msManifestFile.Dispose();
}
if (msSignatureFileBody != null)
{
msSignatureFileBody.Dispose();
}
if (msManifestFile != null)
{
msManifestFile.Dispose();
}
if (msSigFile != null)
{
msSigFile.Dispose();
}
}
}