public static byte[] UnscrambledPayload(this SPCMessage message, RSAParameters parameters)
{
ArgumentThrow.IfNull(message, $"Invalid {typeof(SPCMessage).Name} to unscramble. Message can not be null.", nameof(message));
ArgumentThrow.IfNull(parameters, $"Invalid {typeof(SPCMessage).Name} to unscramble. {typeof(RSAParameters).Name} can not be null.", nameof(parameters));
using (var rsa = RSA.Create())
using (var aes = Aes.Create())
{
rsa.ImportParameters(parameters);
aes.IV = message.IV;
aes.Key = rsa.Decrypt(message.Key, RSAEncryptionPadding.OaepSHA1);
aes.Mode = CipherMode.CBC;
aes.Padding = PaddingMode.None;
using (var decryptor = aes.CreateDecryptor())
using (var memoryStream = new MemoryStream())
using (var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Write))
{
cryptoStream.Write(message.ContentPayload);
return(memoryStream.ToArray());
}
}
}
internal DFunction(byte[] ask, bool encryption = true)
{
ArgumentThrow.IfLengthNot(ask, 16, "Only 16-bytes ASKs are valid.", nameof(ask));
this.ASK = ask;
this.encryption = encryption;
}
public FPExtractor(FPProvider provider)
{
ArgumentThrow.IfNull(provider, "Unable to create inspector. Provider can not be null.", nameof(provider));
this.Providers = new List <FPProvider>()
{
provider
};
}
internal static byte[] ToBuffer(IEnumerable <TLLVSlab> slabs)
{
ArgumentThrow.IfNull(slabs, $"Invalid slabs to serialize. Slab list can not be null.", nameof(slabs));
var memory = new MemoryStream();
foreach (var slab in slabs)
{
memory.Write(slab.Binary);
}
return(memory.ToArray());
}
public FPServer(FPProvider provider, IContentKeyLocator locator)
{
ArgumentThrow.IfNull(provider, "Unable to create server. Provider can not be null.", nameof(provider));
ArgumentThrow.IfNull(locator, "Unable to create server. Key locator can not be null.", nameof(locator));
this.Providers = new List <FPProvider>()
{
provider
};
this.Locator = locator;
this.LicenseDuration = 3600;
}
internal static IEnumerable <TLLVSlab> FromBuffer(byte[] buffer)
{
ArgumentThrow.IfNull(buffer, $"Invalid buffer to parse slabs. Buffer can not be null.", nameof(buffer));
var memory = new ReadOnlyMemory <byte>(buffer);
IList <TLLVSlab> slabs = new List <TLLVSlab>();
while (memory.Length > 0)
{
var slab = new TLLVSlab(memory);
slabs.Add(slab);
memory = memory.Slice((int)slab.Length);
}
return(slabs);
}
public static byte[] UnscrambledParcel(this SKR1Payload payload, byte[] key)
{
ArgumentThrow.IfNull(payload, $"Invalid {typeof(SKR1Payload).Name} to unscramble. Payload can not be null.", nameof(payload));
ArgumentThrow.IfLengthNot(key, 16, "Invalid key to unscramble. Key buffer should be 16 bytes.", nameof(key));
using (var aes = Aes.Create())
{
aes.IV = payload.IV;
aes.Key = key;
aes.Mode = CipherMode.CBC;
aes.Padding = PaddingMode.None;
using (var decryptor = aes.CreateDecryptor())
using (var memoryStream = new MemoryStream())
using (var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Write))
{
cryptoStream.Write(payload.Parcel);
return(memoryStream.ToArray());
}
}
}
public static byte[] ScrambledParcel(this EncryptedCKParcel parcel, byte[] key)
{
ArgumentThrow.IfNull(parcel, $"Invalid {typeof(EncryptedCKParcel).Name} to scramble. Parcel can not be null.", nameof(parcel));
ArgumentThrow.IfLengthNot(key, 16, "Invalid key to scramble. Key buffer should be 16 bytes.", nameof(key));
using (var aes = Aes.Create())
{
// aes.IV = null;
aes.Key = key;
aes.Mode = CipherMode.ECB;
aes.Padding = PaddingMode.None;
using (var encryptor = aes.CreateEncryptor())
using (var memoryStream = new MemoryStream())
using (var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
{
cryptoStream.Write(parcel.Binary);
return(memoryStream.ToArray());
}
}
}
public static byte[] ScrambledPayload(byte[] payload, byte[] iv, byte[] key)
{
ArgumentThrow.IfLengthNotMultiple(payload, 16, "Invalid payload to scramble. The buffer length should be multiple of 16.", nameof(payload));
ArgumentThrow.IfLengthNot(iv, 16, "Invalid key to scramble. Key buffer should be 16 bytes.", nameof(iv));
ArgumentThrow.IfLengthNot(key, 16, "Invalid key to scramble. Key buffer should be 16 bytes.", nameof(key));
using (var aes = Aes.Create())
{
aes.IV = iv;
aes.Key = key;
aes.Mode = CipherMode.CBC;
aes.Padding = PaddingMode.None;
using (var encryptor = aes.CreateEncryptor())
using (var memoryStream = new MemoryStream())
using (var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
{
cryptoStream.Write(payload);
return(memoryStream.ToArray());
}
}
}
internal byte[] DeriveBytes(byte[] bytes)
{
ArgumentThrow.IfLackingBytes(bytes, 1, "Invalid derivation buffer. The buffer seems to have a length lower than 1.", nameof(bytes));
ArgumentThrow.IfTooMuchBytes(bytes, 55, "Invalid derivation buffer. The buffer seems to have a length greater than 55.", nameof(bytes));
var buffer = new ReadOnlyMemory <byte>(bytes);
var memory = new Memory <byte>(new byte[64]);
buffer.CopyTo(memory.Slice(0, buffer.Length));
BinaryConverter.WriteUInt8(0x80).CopyTo(memory.Slice(buffer.Length, 1));
UInt32 M1 = Enumerable.Range(0, 7).Select(i => BinaryConverter.ReadUInt32(memory.Slice(i * 4, 4), BinaryConverter.Endianess.BigEndian)).Aggregate((i, j) => i + j);
for (int i = 0; i < ROUNDS; i++)
{
if ((M1 & 1) == 0)
{
M1 = (3 * M1 + 1) % PRIME;
}
else
{
M1 >>= 1;
}
}
UInt32 M2 = Enumerable.Range(7, 7).Select(i => BinaryConverter.ReadUInt32(memory.Slice(i * 4, 4), BinaryConverter.Endianess.BigEndian)).Aggregate((i, j) => i + j);
for (int i = 0; i < ROUNDS; i++)
{
if ((M2 & 1) == 0)
{
M2 = (3 * M2 + 1) % PRIME;
}
else
{
M2 >>= 1;
}
}
BinaryConverter.WriteUInt32(M1, BinaryConverter.Endianess.LittleEndian).CopyTo(memory.Slice(56, 4));
BinaryConverter.WriteUInt32(M2, BinaryConverter.Endianess.LittleEndian).CopyTo(memory.Slice(60, 4));
using (var sha = SHA1.Create())
using (var aes = Aes.Create())
{
var hash = sha.ComputeHash(memory.ToArray()).Take(16).ToArray();
// aes.IV = new byte[16];
aes.Key = this.ASK;
aes.Mode = CipherMode.ECB;
aes.Padding = PaddingMode.None;
using (var encryptor = aes.CreateEncryptor())
using (var memoryStream = new MemoryStream())
using (var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
{
cryptoStream.Write(hash);
return(encryption ? memoryStream.ToArray() : hash);
}
}
}
