/// <summary>
/// This is called from an expressInterest OnData to check that the encryption
/// key contained in data fits the timeSlot. This sends a refined interest if
/// required.
/// </summary>
///
/// <param name="interest">The interest given to expressInterest.</param>
/// <param name="data">The fetched Data packet.</param>
/// <param name="timeSlot_0">The time slot as milliseconds since Jan 1, 1970 UTC.</param>
/// <param name="onEncryptedKeys_1">encrypted content key Data packets. If onEncryptedKeys is null, this does not use it.</param>
internal void handleCoveringKey(Interest interest, Data data,
double timeSlot_0, Producer.OnEncryptedKeys onEncryptedKeys_1, net.named_data.jndn.encrypt.EncryptError.OnError onError_2)
{
double timeCount = Math.Round(timeSlot_0, MidpointRounding.AwayFromZero);
Producer.KeyRequest keyRequest = (Producer.KeyRequest)ILOG.J2CsMapping.Collections.Collections.Get(keyRequests_, timeCount);
Name interestName = interest.getName();
Name keyName = data.getName();
double begin = net.named_data.jndn.encrypt.Schedule.fromIsoString(keyName
.get(START_TIME_STAMP_INDEX).getValue().toString());
double end = net.named_data.jndn.encrypt.Schedule.fromIsoString(keyName.get(END_TIME_STAMP_INDEX)
.getValue().toString());
if (timeSlot_0 >= end)
{
// If the received E-KEY covers some earlier period, try to retrieve an
// E-KEY covering a later one.
Exclude timeRange = new Exclude(interest.getExclude());
excludeBefore(timeRange, keyName.get(START_TIME_STAMP_INDEX));
ILOG.J2CsMapping.Collections.Collections.Put(keyRequest.repeatAttempts, interestName, 0);
sendKeyInterest(new Interest(interestName).setExclude(timeRange)
.setChildSelector(1), timeSlot_0, onEncryptedKeys_1, onError_2);
}
else
{
// If the received E-KEY covers the content key, encrypt the content.
Blob encryptionKey = data.getContent();
// If everything is correct, save the E-KEY as the current key.
if (encryptContentKey(encryptionKey, keyName, timeSlot_0,
onEncryptedKeys_1, onError_2))
{
Producer.KeyInfo keyInfo = (Producer.KeyInfo)ILOG.J2CsMapping.Collections.Collections.Get(eKeyInfo_, interestName);
keyInfo.beginTimeSlot = begin;
keyInfo.endTimeSlot = end;
keyInfo.keyBits = encryptionKey;
}
}
}
/// <summary>
/// Create the content key corresponding to the timeSlot. This first checks if
/// the content key exists. For an existing content key, this returns the
/// content key name directly. If the key does not exist, this creates one and
/// encrypts it using the corresponding E-KEYs. The encrypted content keys are
/// passed to the onEncryptedKeys callback.
/// </summary>
///
/// <param name="timeSlot_0">The time slot as milliseconds since Jan 1, 1970 UTC.</param>
/// <param name="onEncryptedKeys_1">content key Data packets. If onEncryptedKeys is null, this does not use it. NOTE: The library will log any exceptions thrown by this callback, but for better error handling the callback should catch and properly handle any exceptions.</param>
/// <param name="onError_2">better error handling the callback should catch and properly handle any exceptions.</param>
/// <returns>The content key name.</returns>
public Name createContentKey(double timeSlot_0,
Producer.OnEncryptedKeys onEncryptedKeys_1, net.named_data.jndn.encrypt.EncryptError.OnError onError_2)
{
double hourSlot = getRoundedTimeSlot(timeSlot_0);
// Create the content key name.
Name contentKeyName = new Name(namespace_);
contentKeyName.append(net.named_data.jndn.encrypt.algo.Encryptor.NAME_COMPONENT_C_KEY);
contentKeyName.append(net.named_data.jndn.encrypt.Schedule.toIsoString(hourSlot));
Blob contentKeyBits;
// Check if we have created the content key before.
if (database_.hasContentKey(timeSlot_0))
{
// We have created the content key. Return its name directly.
return(contentKeyName);
}
// We haven't created the content key. Create one and add it into the database.
AesKeyParams aesParams = new AesKeyParams(128);
contentKeyBits = net.named_data.jndn.encrypt.algo.AesAlgorithm.generateKey(aesParams).getKeyBits();
database_.addContentKey(timeSlot_0, contentKeyBits);
// Now we need to retrieve the E-KEYs for content key encryption.
double timeCount = Math.Round(timeSlot_0, MidpointRounding.AwayFromZero);
ILOG.J2CsMapping.Collections.Collections.Put(keyRequests_, timeCount, new Producer.KeyRequest(eKeyInfo_.Count));
Producer.KeyRequest keyRequest = (Producer.KeyRequest)ILOG.J2CsMapping.Collections.Collections.Get(keyRequests_, timeCount);
// Check if the current E-KEYs can cover the content key.
Exclude timeRange = new Exclude();
excludeAfter(timeRange,
new Name.Component(net.named_data.jndn.encrypt.Schedule.toIsoString(timeSlot_0)));
new ILOG.J2CsMapping.Collections.IteratorAdapter(eKeyInfo_.GetEnumerator());
for (IIterator i = new ILOG.J2CsMapping.Collections.IteratorAdapter(eKeyInfo_.GetEnumerator()); i.HasNext();)
{
// For each current E-KEY.
DictionaryEntry entry = (DictionaryEntry)i.Next();
Producer.KeyInfo keyInfo = (Producer.KeyInfo)((DictionaryEntry)entry).Value;
if (timeSlot_0 < keyInfo.beginTimeSlot ||
timeSlot_0 >= keyInfo.endTimeSlot)
{
// The current E-KEY cannot cover the content key, so retrieve one.
ILOG.J2CsMapping.Collections.Collections.Put(keyRequest.repeatAttempts, ((DictionaryEntry)entry).Key, 0);
sendKeyInterest(
new Interest((Name)((DictionaryEntry)entry).Key).setExclude(
timeRange).setChildSelector(1), timeSlot_0,
onEncryptedKeys_1, onError_2);
}
else
{
// The current E-KEY can cover the content key.
// Encrypt the content key directly.
Name eKeyName = new Name((Name)((DictionaryEntry)entry).Key);
eKeyName.append(net.named_data.jndn.encrypt.Schedule.toIsoString(keyInfo.beginTimeSlot));
eKeyName.append(net.named_data.jndn.encrypt.Schedule.toIsoString(keyInfo.endTimeSlot));
encryptContentKey(keyInfo.keyBits, eKeyName, timeSlot_0,
onEncryptedKeys_1, onError_2);
}
}
return(contentKeyName);
}
