public static byte[] GetDiscoveryResponseData(DiscoveryResponse response, ICollection <RemoteAttestation> attestations)
{
foreach (RemoteAttestation attestation in attestations)
{
if (Enumerable.SequenceEqual(response.RequestId, attestation.RequestId))
{
return(AesCipher.Decrypt(attestation.Keys.ServerKey, response.Iv !, response.Data !, response.Mac !));
}
}
throw new NoMatchingRequestIdException();
}
public static DiscoveryRequest CreateDiscoveryRequest(IList <string> addressBook, Dictionary <string, RemoteAttestation> remoteAttestations)
{
byte[] queryDataKey = Util.GetSecretBytes(32);
byte[] queryData = BuildQueryData(addressBook);
AesCipher.AesEncryptedResult encryptedQueryData = AesCipher.Encrypt(queryDataKey, null, queryData);
byte[] commitment = CryptoUtil.Sha256(queryData);
Dictionary <string, QueryEnvelope> envelopes = new Dictionary <string, QueryEnvelope>(remoteAttestations.Count);
foreach (var entry in remoteAttestations)
{
envelopes.Add(entry.Key,
BuildQueryEnvelope(entry.Value.RequestId, entry.Value.Keys.ClientKey, queryDataKey));
}
return(new DiscoveryRequest(addressBook.Count,
commitment,
encryptedQueryData.iv,
encryptedQueryData.data,
encryptedQueryData.mac,
envelopes));
}
private static QueryEnvelope BuildQueryEnvelope(byte[] requestId, byte[] clientKey, byte[] queryDataKey)
{
AesCipher.AesEncryptedResult result = AesCipher.Encrypt(clientKey, requestId, queryDataKey);
return(new QueryEnvelope(requestId, result.iv, result.data, result.mac));
}
public static byte[] GetRequestId(RemoteAttestationKeys keys, RemoteAttestationResponse response)
{
return(AesCipher.Decrypt(keys.ServerKey, response.Iv, response.Ciphertext, response.Tag));
}
