/*
* Only encrypts the given MimeEntity.
*/
private MultipartEncrypted EncryptEntity(Node entityNode, MimeEntity entity)
{
// Retrieving node that declares encryption settings for us.
var encryptionNode = entityNode ["encrypt"];
// Retrieving MailboxAddresses to encrypt message for.
var receivers = GetReceiversMailboxAddress(encryptionNode);
// Creating our Gnu Privacy Guard context.
// Notice, no password necessary when doing encryption, since we're only using public certificates.
using (var ctx = new GnuPrivacyContext()) {
// Encrypting content of email and returning to caller.
var retVal = MultipartEncrypted.Encrypt(
ctx,
receivers,
entity);
// Setting preamble and epilogue AFTER encryption, to give opportunity to give hints to receiver.
retVal.Preamble = entityNode.GetChildValue <string> ("preamble", _context, null);
retVal.Epilogue = entityNode.GetChildValue <string> ("epilogue", _context, null);
// Returning encrypted Multipart.
return(retVal);
}
}
/*
* Processes an encrypted Multipart.
*/
private void ProcessEncryptedMultipart(MultipartEncrypted encryptedMultipart, Node entityNode)
{
try {
// Creating cryptographic context.
using (var ctx = new GnuPrivacyContext()) {
// Associating our KeyPasswordMapper collection with GnuPG CryptographyContext.
ctx.Passwords = _passwords;
// Decrypting entity, making sure we retrieve signatures at the same time, if there are any.
DigitalSignatureCollection signatures;
var decryptedMultipart = encryptedMultipart.Decrypt(ctx, out signatures);
// Making sure caller gets notified of which private key was used for decrypting encrypted multipart.
entityNode.Add("decryption-key", ctx.LastUsedUserId);
// Adding signatures.
ProcessSignatures(entityNode, signatures);
// Parsing decrypted result.
ProcessEntity(decryptedMultipart, entityNode);
}
} catch (Exception err) {
// Couldn't decrypt Multipart, returning raw encrypted content.
entityNode.Add("processing-message", err.Message);
foreach (var idxEntity in encryptedMultipart)
{
ProcessEntity(idxEntity, entityNode);
}
}
}
/*
* Only signs the given MimeEntity
*/
private MultipartSigned SignEntity(
Node entityNode,
MimeEntity entity)
{
// Retrieving signature node to use for signing operation
var signatureNode = entityNode ["signature"];
// Getting signature email as provided by caller
var signatureAddress = GetSignatureMailboxAddress(signatureNode);
// Figuring out signature Digest Algorithm to use for signature, defaulting to Sha256
var algo = signatureNode.GetChildValue("digest-algorithm", _context, DigestAlgorithm.Sha256);
// Creating our Gnu Privacy Guard context
using (var ctx = new GnuPrivacyContext()) {
// Setting password to retrieve signing certificate from GnuPG context
ctx.Password = signatureAddress.Item1;
// Signing content of email and returning to caller
return(MultipartSigned.Create(
ctx,
signatureAddress.Item2,
algo,
entity));
}
}
/*
* Processes a signed Multipart.
*/
private void ProcessSignedMultipart(MultipartSigned signedMultipart, Node entityNode)
{
// Creating cryptographic context.
using (var ctx = new GnuPrivacyContext()) {
// Adding signatures.
ProcessSignatures(entityNode, signedMultipart.Verify(ctx));
// Looping through all entities in Multipart, processing recursively.
foreach (var idxEntity in signedMultipart)
{
ProcessEntity(idxEntity, entityNode);
}
}
}
/*
* Iterates all public keys in all keyrings in GnuPrivacyContext, and invokes given delegate for every key matching filter condition.
*/
internal static void MatchingPublicKeys(ApplicationContext context, Node args, MatchingPublicKeysDelegate functor, bool write)
{
// House cleaning.
using (new ArgsRemover(args, true)) {
// Storing all filter given by caller in list, to avoid destroying enumeration iterator, due to modifying collection in caller's callback.
var filters = XUtil.Iterate <string> (context, args).Where(ix => ix != null).ToList();
// Creating new GnuPG context.
using (var ctx = new GnuPrivacyContext(write)) {
// Iterating all secret keyrings.
foreach (PgpPublicKeyRing idxRing in ctx.PublicKeyRingBundle.GetKeyRings())
{
// Iterating all keys in currently iterated secret keyring.
foreach (PgpPublicKey idxPublicKey in idxRing.GetPublicKeys())
{
// Verifying that this is a normal plain public key.
// Notice, we only return keys with at least one User ID.
if (!idxPublicKey.GetUserIds().GetEnumerator().MoveNext())
{
continue; // Probably just a signature for another key, or something.
}
// Checking if caller provided filters, and if not, yielding "everything".
if (filters.Count == 0)
{
// No filters provided, matching everything.
functor(idxPublicKey);
}
else
{
// Iterating all filters given by caller.
foreach (var idxFilter in filters)
{
// Checking if current filter is a match.
if (IsMatch(idxPublicKey, idxFilter))
{
// Invoking callback supplied by caller, and breaking current filter enumeration, to avoid adding key twice.
functor(idxPublicKey);
break;
}
}
}
}
}
}
}
}
/*
* Iterates all public keys in all keyrings in GnuPrivacyContext, and invokes given delegate for every key matching filter condition.
*/
internal static void MatchingPublicKeys(ApplicationContext context, Node args, MatchingPublicKeysDelegate functor)
{
// House cleaning.
using (new ArgsRemover(args, true)) {
// Storing all filter given by caller in list, to avoid destroying enumeration iterator, due to modifying collection in caller's callback.
var filters = XUtil.Iterate <string> (context, args).Where(ix => ix != null).ToList();
// Creating new GnuPG context.
using (var ctx = new GnuPrivacyContext()) {
// Iterating all secret keyrings.
foreach (PgpPublicKeyRing idxRing in ctx.PublicKeyRingBundle.GetKeyRings())
{
// Iterating all keys in currently iterated secret keyring.
foreach (PgpPublicKey idxPublicKey in idxRing.GetPublicKeys())
{
// Checking if caller provided filters, and if not, yielding "everything".
if (filters.Count == 0)
{
// No filters provided, matching everything.
functor(idxPublicKey);
}
else
{
// Iterating all filters given by caller.
foreach (var idxFilter in filters)
{
// Checking if current filter is a match.
if (IsMatch(idxPublicKey, idxFilter))
{
// Invoking callback supplied by caller, and breaking current filter enumeration, to avoid adding key twice.
functor(idxPublicKey);
break;
}
}
}
}
}
}
}
}
/*
* Signs and encrypts the given MimeEntity.
*/
private MultipartEncrypted SignAndEncryptEntity(
Node entityNode,
MimeEntity entity)
{
// Retrieving [sign] and [encrypt] nodes.
var signatureNode = entityNode ["sign"];
var encryptionNode = entityNode ["encrypt"];
// Getting signature email as provided by caller.
var signatureAddress = GetSignatureMailboxAddress(signatureNode);
// Retrieving MailboxAddresses to encrypt message for.
var receivers = GetReceiversMailboxAddress(encryptionNode);
// Figuring out signature Digest Algorithm to use for signature, defaulting to Sha256.
var algo = signatureNode.GetChildValue("digest-algorithm", _context, DigestAlgorithm.Sha256);
// Creating our Gnu Privacy Guard context.
using (var ctx = new GnuPrivacyContext()) {
// Setting password to retrieve signing certificate from GnuPG context.
ctx.Password = signatureAddress.Item1;
// Signing and Encrypting content of email.
var retVal = MultipartEncrypted.SignAndEncrypt(
ctx,
signatureAddress.Item2,
algo,
receivers,
entity);
// Setting preamble and epilogue AFTER encryption, to give opportunity to give receiver hints.
retVal.Preamble = entityNode.GetChildValue <string> ("preamble", _context, null);
retVal.Epilogue = entityNode.GetChildValue <string> ("epilogue", _context, null);
// Returning encrypted Multipart.
return(retVal);
}
}