public static Message DecodeFromBytes(byte[] messageData, Tags defaultTag = Tags.Unknown)
{
CBORObject messageObject = CBORObject.DecodeFromBytes(messageData);
if (messageObject.Type != CBORType.Array)
{
throw new CoseException("Message is not a COSE security message.");
}
if (messageObject.IsTagged)
{
if (messageObject.GetTags().Count() != 1)
{
throw new CoseException("Malformed message - too many tags");
}
if (defaultTag == Tags.Unknown)
{
defaultTag = (COSE.Tags)messageObject.OutermostTag.intValue();
}
else if (defaultTag != (COSE.Tags)messageObject.OutermostTag.intValue())
{
throw new CoseException("Passed in tag does not match actual tag");
}
}
switch (defaultTag)
{
case Tags.Unknown:
throw new CoseException("Message was not tagged and no default tagging option given");
case Tags.Signed:
SignMessage sig = new SignMessage();
sig.DecodeFromCBORObject(messageObject);
return(sig);
case Tags.Signed0:
Sign0Message sig0 = new Sign0Message();
sig0.DecodeFromCBORObject(messageObject);
return(sig0);
case Tags.MAC: {
MACMessage mac = new MACMessage();
mac.DecodeFromCBORObject(messageObject);
return(mac);
}
case Tags.MAC0:
MAC0Message mac0 = new MAC0Message();
mac0.DecodeFromCBORObject(messageObject);
return(mac0);
case Tags.Enveloped: // It is an encrytion message
EnvelopedMessage enc = new EnvelopedMessage();
enc.DecodeFromCBORObject(messageObject);
return(enc);
case Tags.Encrypted:
EncryptMessage enc0 = new EncryptMessage();
enc0.DecodeFromCBORObject(messageObject);
return(enc0);
default:
throw new CoseException("Message is not recognized as a COSE security message.");
}
}
