private void ivParamTest(
int count,
CcmBlockCipher ccm,
byte[] k,
byte[] n)
{
byte[] p = Encoding.ASCII.GetBytes("hello world!!");
ccm.Init(true, new ParametersWithIV(new KeyParameter(k), n));
byte[] enc = new byte[p.Length + 8];
int len = ccm.ProcessBytes(p, 0, p.Length, enc, 0);
len += ccm.DoFinal(enc, len);
ccm.Init(false, new ParametersWithIV(new KeyParameter(k), n));
byte[] tmp = new byte[enc.Length];
len = ccm.ProcessBytes(enc, 0, enc.Length, tmp, 0);
len += ccm.DoFinal(tmp, len);
byte[] dec = new byte[len];
Array.Copy(tmp, 0, dec, 0, len);
if (!AreEqual(p, dec))
{
Fail("decrypted stream fails to match in test " + count);
}
}
private void checkVectors(
int count,
CcmBlockCipher ccm,
byte[] k,
int macSize,
byte[] n,
byte[] a,
byte[] p,
byte[] t,
byte[] c)
{
ccm.Init(true, new AeadParameters(new KeyParameter(k), macSize, n, a));
byte[] enc = new byte[c.Length];
int len = ccm.ProcessBytes(p, 0, p.Length, enc, 0);
len += ccm.DoFinal(enc, len);
// ccm.Init(true, new CcmParameters(new KeyParameter(k), macSize, n, a));
//
// byte[] enc = ccm.ProcessPacket(p, 0, p.Length);
if (!AreEqual(c, enc))
{
Fail("encrypted stream fails to match in test " + count);
}
// ccm.Init(false, new CcmParameters(new KeyParameter(k), macSize, n, a));
//
// byte[] dec = ccm.ProcessPacket(enc, 0, enc.Length);
ccm.Init(false, new AeadParameters(new KeyParameter(k), macSize, n, a));
byte[] tmp = new byte[enc.Length];
len = ccm.ProcessBytes(enc, 0, enc.Length, tmp, 0);
len += ccm.DoFinal(tmp, len);
byte[] dec = new byte[len];
Array.Copy(tmp, 0, dec, 0, len);
if (!AreEqual(p, dec))
{
Fail("decrypted stream fails to match in test " + count);
}
if (!AreEqual(t, ccm.GetMac()))
{
Fail("MAC fails to match in test " + count);
}
}
public string Decrypt(string json, string password)
{
var jsonObj = JsonConvert.DeserializeObject <SjclJson>(json);
var v = jsonObj.V;
var adata = Convert.FromBase64String(jsonObj.AData);
var iv = Convert.FromBase64String(jsonObj.IV);
var salt = Convert.FromBase64String(jsonObj.Salt);
var ks = jsonObj.KS;
var ts = jsonObj.TS;
var iter = jsonObj.Iter;
var ct = Convert.FromBase64String(jsonObj.CT);
// var cipher = json.Cipher;
// var mode = json.Mode;
var key = GenKeyBytes(password, salt, ks, iter);
var nonSecretPayload = new byte[] { };
var cipher = new CcmBlockCipher(new AesFastEngine());
var parameters = new CcmParameters(
new KeyParameter(key), ts, iv.Take(13).ToArray(), nonSecretPayload);
cipher.Init(false, parameters);
var plainText = new byte[cipher.GetOutputSize(ct.Length)];
var len = cipher.ProcessBytes(ct, 0, ct.Length, plainText, 0);
cipher.DoFinal(plainText, len);
return(Encoding.UTF8.GetString(plainText));
}
public static string Decrypt(string password, string data)
{
SJCLBlob ctdata = JsonConvert.DeserializeObject <SJCLBlob>(data);
if (ctdata.Cipher != "aes" || ctdata.Mode != "ccm")
{
throw new InvalidOperationException("Unsupported cipher or mode.");
}
byte[] cipherText = DecodeBase64(ctdata.CipherText);
var derivedMacParameters = DeriveKey(password, ctdata);
var l = FindIVLen(cipherText.Length);
byte[] iv = new byte[l];
Array.Copy((Array)DecodeBase64(ctdata.IV), (Array)iv, (int)l);
var ccmparams = new CcmParameters(derivedMacParameters, ctdata.TagSize, iv, DecodeBase64(ctdata.AuthData));
var ccmMode = new CcmBlockCipher(new AesFastEngine());
ccmMode.Init(false, ccmparams);
var plainBytes = new byte[ccmMode.GetOutputSize(cipherText.Length)];
var res = ccmMode.ProcessBytes(cipherText, 0, cipherText.Length, plainBytes, 0);
ccmMode.DoFinal(plainBytes, res);
return(Encoding.UTF8.GetString(plainBytes));
}
internal override void Evaluate(EngineProvider provider)
{
byte[] K = Hex.Decode("404142434445464748494a4b4c4d4e4f");
byte[] N = Hex.Decode("10111213141516");
byte[] A = Hex.Decode("0001020304050607");
byte[] P = Hex.Decode("20212223");
byte[] C = Hex.Decode("7162015b4dac255d");
byte[] T = Hex.Decode("6084341b");
CcmBlockCipher encCipher = new CcmBlockCipher(provider.CreateEngine(EngineUsage.GENERAL));
CcmBlockCipher decCipher = new CcmBlockCipher(provider.CreateEngine(EngineUsage.GENERAL));
int macSize = T.Length * 8;
KeyParameter keyParam = new KeyParameter(K);
encCipher.Init(true, new AeadParameters(keyParam, macSize, N, A));
byte[] enc = new byte[C.Length];
int len = encCipher.ProcessBytes(P, 0, P.Length, enc, 0);
encCipher.DoFinal(enc, len);
if (!Arrays.AreEqual(FipsKats.Values[FipsKats.Vec.AesCcmEnc], enc))
{
Fail("encrypted stream fails to match in self test");
}
if (!Arrays.AreEqual(FipsKats.Values[FipsKats.Vec.AesCcmEncTag], encCipher.GetMac()))
{
Fail("MAC fails to match in self test encrypt");
}
decCipher.Init(false, new AeadParameters(keyParam, macSize, N, A));
byte[] tmp = new byte[enc.Length];
len = decCipher.ProcessBytes(enc, 0, enc.Length, tmp, 0);
len += decCipher.DoFinal(tmp, len);
byte[] dec = new byte[len];
Array.Copy(tmp, 0, dec, 0, len);
if (!Arrays.AreEqual(FipsKats.Values[FipsKats.Vec.AesCcmDec], dec))
{
Fail("decrypted stream fails to match in self test");
}
if (!Arrays.AreEqual(FipsKats.Values[FipsKats.Vec.AesCcmDecTag], decCipher.GetMac()))
{
Fail("MAC fails to match in self test");
}
}
public JObject Decrypt(string key, JObject json)
{
try
{
byte[] iv = Base64.Decode(json.GetValue("iv").ToString());
byte[] cipherText = Base64.Decode(json.GetValue("ct").ToString());
byte[] adataBytes = DecodeAdataBytes(json.GetValue("adata").ToString());
byte[] nonce = ComputeNonce(iv, cipherText);
if (json.GetValue("mode").ToString() != "ccm")
{
throw new ApplicationException("Can only decrypt ccm mode encrypted data.");
}
KeyParameter keyParam = CreateKey(
key,
Base64.Decode(json.GetValue("salt").ToString()),
json.GetValue("iter").ToObject <int>(),
json.GetValue("ks").ToObject <int>());
var ccm = new AeadParameters(
keyParam,
MacSize(json.GetValue("ts").ToObject <int>()),
nonce,
adataBytes);
var aes = new CcmBlockCipher(new AesFastEngine());
aes.Init(false, ccm);
var plainBytes = new byte[aes.GetOutputSize(cipherText.Length)];
int res = aes.ProcessBytes(
cipherText,
0,
cipherText.Length,
plainBytes,
0);
aes.DoFinal(plainBytes, res);
var text = Encoding.UTF8.GetString(plainBytes);
return(JObject.Parse(text));
}
catch (InvalidCipherTextException)
{
throw;
}
catch (Exception e)
{
throw new ApplicationException("Json decryption failed.", e);
}
}
private static MemoryStream Encrypt(Stream source, string fileName, out string seed_encoded, out string ident)
{
// Randomly generate a new seed for upload
byte[] seed = new byte[16];
using (RNGCryptoServiceProvider rngCsp = new RNGCryptoServiceProvider())
{
rngCsp.GetBytes(seed);
}
seed_encoded = UrlBase64Encode(seed);
// Derive the parameters (key, IV, ident) from the seed
byte[] key, iv;
DeriveParams(seed, out key, out iv, out ident);
// Create a new String->String map for JSON blob, and define filename and metadata
Dictionary <string, string> metadataMap = new Dictionary <string, string>();
metadataMap["mime"] = Helpers.IsTextFile(fileName) ? "text/plain" : Helpers.GetMimeType(fileName);
metadataMap["name"] = fileName;
// Encode the metadata with UTF-16 and a double-null-byte terminator, and append data
// Unfortunately, the CCM cipher mode can't stream the encryption, and so we have to GetBytes() on the source.
// We do limit the source to 50MB however
byte[] data = Encoding.BigEndianUnicode.GetBytes(JsonConvert.SerializeObject(metadataMap)).Concat(new byte[] { 0, 0 }).Concat(source.GetBytes()).ToArray();
// Calculate the length of the CCM IV and copy it over
long ccmIVLen = FindIVLen(data.Length);
byte[] ccmIV = new byte[ccmIVLen];
Array.Copy(iv, ccmIV, ccmIVLen);
// Set up the encryption parameters
KeyParameter keyParam = new KeyParameter(key);
CcmParameters ccmParams = new CcmParameters(keyParam, MacSize, ccmIV, new byte[0]);
CcmBlockCipher ccmMode = new CcmBlockCipher(new AesFastEngine());
ccmMode.Init(true, ccmParams);
// Perform the encryption
byte[] encBytes = new byte[ccmMode.GetOutputSize(data.Length)];
int res = ccmMode.ProcessBytes(data, 0, data.Length, encBytes, 0);
ccmMode.DoFinal(encBytes, res);
return(new MemoryStream(encBytes));
}
public JObject Encrypt(string key, JObject blob, string adata)
{
var result = new JObject();
var random = new SecureRandom();
var iv = new byte[32];
var salt = new byte[8];
random.NextBytes(salt);
random.NextBytes(iv);
try
{
byte[] plainBytes = Encoding.UTF8.GetBytes(blob.ToString());
byte[] adataBytes = Encoding.UTF8.GetBytes(adata);
byte[] nonce = ComputeNonce(iv, plainBytes);
KeyParameter keyParam = CreateKey(key, salt, _iter, _ks);
var ccm = new AeadParameters(keyParam, MacSize(_ts), nonce, adataBytes);
var aes = new CcmBlockCipher(new AesFastEngine());
aes.Init(true, ccm);
var enc = new byte[aes.GetOutputSize(plainBytes.Length)];
int res = aes.ProcessBytes(plainBytes, 0, plainBytes.Length, enc, 0);
aes.DoFinal(enc, res);
result.Add("ct", Base64.ToBase64String(enc));
result.Add("iv", Base64.ToBase64String(iv));
result.Add("salt", Base64.ToBase64String(salt));
result.Add("adata", EncodeAdata(adata));
result.Add("mode", Mode);
result.Add("ks", _ks);
result.Add("iter", _iter);
result.Add("ts", _ts);
return(result);
}
catch (Exception e)
{
throw new ApplicationException("Json encryption failed.", e);
}
}
public string Encrypt(string plainText, string password)
{
var v = 1;
var iter = 10000;
var ks = 256;
var ts = 64;
// var mode = "ccm";
// var cipher = "aes";
var plainTextBytes = Encoding.UTF8.GetBytes(plainText);
var adata = new byte[0];
var iv = new byte[16];
var salt = new byte[8];
_random.GetBytes(iv);
_random.GetBytes(salt);
var key = GenKeyBytes(password, salt, ks, iter);
var nonSecretPayload = new byte[] { };
var cipher = new CcmBlockCipher(new AesFastEngine());
var parameters = new CcmParameters(
new KeyParameter(key), ts, iv.Take(13).ToArray(), nonSecretPayload);
cipher.Init(true, parameters);
var cipherText = new byte[cipher.GetOutputSize(plainTextBytes.Length)];
var len = cipher.ProcessBytes(plainTextBytes, 0, plainTextBytes.Length, cipherText, 0);
cipher.DoFinal(cipherText, len);
return(JsonConvert.SerializeObject(new SjclJson
{
IV = Convert.ToBase64String(iv),
V = v,
Iter = iter,
KS = ks,
TS = ts,
Mode = "ccm",
Cipher = "aes",
AData = Convert.ToBase64String(adata),
Salt = Convert.ToBase64String(salt),
CT = Convert.ToBase64String(cipherText),
}));
}
public static string Encrypt(string password, string data)
{
RNGCryptoServiceProvider rngCsp = new RNGCryptoServiceProvider();
byte[] salt = new byte[8];
rngCsp.GetBytes(salt);
byte[] iv = new byte[16];
rngCsp.GetBytes(iv);
SJCLBlob ctdata = new SJCLBlob()
{
Mode = "ccm",
Cipher = "aes",
AuthData = "",
Iterations = 2000,
KeySize = 256,
TagSize = 64,
Salt = Convert.ToBase64String(salt),
IV = Convert.ToBase64String(iv),
V = 1
};
var key = DeriveKey(password, ctdata);
byte[] rawdata = Encoding.UTF8.GetBytes(data);
var l = FindIVLen(rawdata.Length);
byte[] civ = new byte[l];
Array.Copy((Array)iv, (Array)civ, (int)l);
var ccmparams = new CcmParameters(key, ctdata.TagSize, civ, DecodeBase64(ctdata.AuthData));
var ccmMode = new CcmBlockCipher(new AesFastEngine());
ccmMode.Init(true, ccmparams);
var encBytes = new byte[ccmMode.GetOutputSize(rawdata.Length)];
var res = ccmMode.ProcessBytes(rawdata, 0, rawdata.Length, encBytes, 0);
ccmMode.DoFinal(encBytes, res);
ctdata.CipherText = Convert.ToBase64String(encBytes);
return(JsonConvert.SerializeObject(ctdata));
}
private void AES_CCM(byte[] k)
{
CcmBlockCipher cipher = new CcmBlockCipher(new AesEngine());
KeyParameter contentKey;
int cbitTag = 64;
// The requirements from JWA
// IV is 96 bits
// Authentication tag is 128 bits
// key sizes are 128, 192 and 256 bits
_iv = new byte[96 / 8];
s_PRNG.NextBytes(_iv);
contentKey = new KeyParameter(k);
// Build the object to be hashed
byte[] a = new byte[0];
if (ProtectedMap != null)
{
a = Encoding.UTF8.GetBytes(ProtectedMap.ToString());
}
AeadParameters parameters = new AeadParameters(contentKey, 128, _iv, a);
cipher.Init(true, parameters);
byte[] c = new byte[cipher.GetOutputSize(payload.Length)];
int len = cipher.ProcessBytes(payload, 0, payload.Length, c, 0);
cipher.DoFinal(c, len);
Array.Resize(ref c, c.Length - (128 / 8) + (cbitTag / 8));
_RgbEncrypted = c;
}
public string Encrypt(string data)
{
SecureRandom random = new SecureRandom();
// Generate 256-bits AES key
byte[] aesKey = new byte[32];
random.NextBytes(aesKey);
// Generate Initialization Vector
byte[] IV = new byte[12];
random.NextBytes(IV);
// Apply RSA/None/PKCS1Padding encryption to the AES key
byte[] encyptedAESKey = rsaCipher.DoFinal(aesKey);
// Apply AES/CCM/NoPadding encryption to the data
byte[] cipherText = System.Text.Encoding.UTF8.GetBytes(data);
var ccmParameters = new CcmParameters(new KeyParameter(aesKey), 64, IV, new byte[] { });
aesCipher = new CcmBlockCipher(new AesFastEngine());
aesCipher.Init(true, ccmParameters);
var encrypted = new byte[aesCipher.GetOutputSize(cipherText.Length)];
var res = aesCipher.ProcessBytes(cipherText, 0, cipherText.Length, encrypted, 0);
aesCipher.DoFinal(encrypted, res);
// Merge 'IV' and 'encrypted' to 'result'
byte[] result = new byte[IV.Length + encrypted.Length];
System.Buffer.BlockCopy(IV, 0, result, 0, IV.Length);
System.Buffer.BlockCopy(encrypted, 0, result, IV.Length, encrypted.Length);
// Return encrypted data
return(Prefix + Version + Separator + System.Convert.ToBase64String(encyptedAESKey) + Separator + System.Convert.ToBase64String(result));
}
public override void PerformTest()
{
CcmBlockCipher ccm = new CcmBlockCipher(new AesEngine());
checkVectors(0, ccm, K1, 32, N1, A1, P1, T1, C1);
checkVectors(1, ccm, K2, 48, N2, A2, P2, T2, C2);
checkVectors(2, ccm, K3, 64, N3, A3, P3, T3, C3);
ivParamTest(0, ccm, K1, N1);
//
// 4 has a reduced associated text which needs to be replicated
//
byte[] a4 = new byte[65536]; // 524288 / 8
for (int i = 0; i < a4.Length; i += A4.Length)
{
Array.Copy(A4, 0, a4, i, A4.Length);
}
checkVectors(3, ccm, K4, 112, N4, a4, P4, T4, C4);
//
// long data test
//
checkVectors(4, ccm, K4, 112, N4, A4, A4, T5, C5);
// decryption with output specified, non-zero offset.
ccm.Init(false, new AeadParameters(new KeyParameter(K2), 48, N2, A2));
byte[] inBuf = new byte[C2.Length + 10];
byte[] outBuf = new byte[ccm.GetOutputSize(C2.Length) + 10];
Array.Copy(C2, 0, inBuf, 10, C2.Length);
int len = ccm.ProcessPacket(inBuf, 10, C2.Length, outBuf, 10);
byte[] output = ccm.ProcessPacket(C2, 0, C2.Length);
if (len != output.Length || !isEqual(output, outBuf, 10))
{
Fail("decryption output incorrect");
}
// encryption with output specified, non-zero offset.
ccm.Init(true, new AeadParameters(new KeyParameter(K2), 48, N2, A2));
int inLen = len;
inBuf = outBuf;
outBuf = new byte[ccm.GetOutputSize(inLen) + 10];
len = ccm.ProcessPacket(inBuf, 10, inLen, outBuf, 10);
output = ccm.ProcessPacket(inBuf, 10, inLen);
if (len != output.Length || !isEqual(output, outBuf, 10))
{
Fail("encryption output incorrect");
}
//
// exception tests
//
try
{
ccm.Init(false, new AeadParameters(new KeyParameter(K1), 32, N2, A2));
ccm.ProcessPacket(C2, 0, C2.Length);
Fail("invalid cipher text not picked up");
}
catch (InvalidCipherTextException)
{
// expected
}
try
{
ccm = new CcmBlockCipher(new DesEngine());
Fail("incorrect block size not picked up");
}
catch (ArgumentException)
{
// expected
}
try
{
ccm.Init(false, new KeyParameter(K1));
Fail("illegal argument not picked up");
}
catch (ArgumentException)
{
// expected
}
}
private void checkVectors(
int count,
CcmBlockCipher ccm,
string additionalDataType,
byte[] k,
int macSize,
byte[] n,
byte[] a,
byte[] sa,
byte[] p,
byte[] t,
byte[] c)
{
KeyParameter keyParam = (k == null) ? null : new KeyParameter(k);
ccm.Init(true, new AeadParameters(keyParam, macSize, n, a));
byte[] enc = new byte[c.Length];
if (sa != null)
{
ccm.ProcessAadBytes(sa, 0, sa.Length);
}
int len = ccm.ProcessBytes(p, 0, p.Length, enc, 0);
len += ccm.DoFinal(enc, len);
// ccm.Init(true, new AeadParameters(new KeyParameter(k), macSize, n, a));
//
// byte[] enc = ccm.ProcessPacket(p, 0, p.Length);
if (!AreEqual(c, enc))
{
Fail("encrypted stream fails to match in test " + count + " with " + additionalDataType);
}
// ccm.Init(false, new AeadParameters(new KeyParameter(k), macSize, n, a));
//
// byte[] dec = ccm.ProcessPacket(enc, 0, enc.Length);
ccm.Init(false, new AeadParameters(new KeyParameter(k), macSize, n, a));
byte[] tmp = new byte[enc.Length];
if (sa != null)
{
ccm.ProcessAadBytes(sa, 0, sa.Length);
}
len = ccm.ProcessBytes(enc, 0, enc.Length, tmp, 0);
len += ccm.DoFinal(tmp, len);
byte[] dec = new byte[len];
Array.Copy(tmp, 0, dec, 0, len);
if (!AreEqual(p, dec))
{
Fail("decrypted stream fails to match in test " + count + " with " + additionalDataType,
Hex.ToHexString(p), Hex.ToHexString(dec));
}
if (!AreEqual(t, ccm.GetMac()))
{
Fail("MAC fails to match in test " + count + " with " + additionalDataType);
}
}
public override void PerformTest()
{
CcmBlockCipher ccm = new CcmBlockCipher(new AesEngine());
checkVectors(0, ccm, K1, 32, N1, A1, P1, T1, C1);
checkVectors(1, ccm, K2, 48, N2, A2, P2, T2, C2);
checkVectors(2, ccm, K3, 64, N3, A3, P3, T3, C3);
ivParamTest(0, ccm, K1, N1);
//
// 4 has a reduced associated text which needs to be replicated
//
byte[] a4 = new byte[65536]; // 524288 / 8
for (int i = 0; i < a4.Length; i += A4.Length)
{
Array.Copy(A4, 0, a4, i, A4.Length);
}
checkVectors(3, ccm, K4, 112, N4, a4, P4, T4, C4);
//
// long data test
//
checkVectors(4, ccm, K4, 112, N4, A4, A4, T5, C5);
//
// exception tests
//
try
{
ccm.Init(false, new AeadParameters(new KeyParameter(K1), 32, N2, A2));
ccm.ProcessPacket(C2, 0, C2.Length);
Fail("invalid cipher text not picked up");
}
catch (InvalidCipherTextException)
{
// expected
}
try
{
ccm = new CcmBlockCipher(new DesEngine());
Fail("incorrect block size not picked up");
}
catch (ArgumentException)
{
// expected
}
try
{
ccm.Init(false, new KeyParameter(K1));
Fail("illegal argument not picked up");
}
catch (ArgumentException)
{
// expected
}
}
private void AES_CCM_Decrypt(CBORObject alg, byte[] K)
{
CcmBlockCipher cipher = new CcmBlockCipher(new AesEngine());
KeyParameter ContentKey;
int cbitTag;
int cbIV;
int cbitKey;
// Figure out what the correct internal parameters to use are
Debug.Assert(alg.Type == CBORType.Integer);
switch ((AlgorithmValuesInt)alg.AsInt32())
{
case AlgorithmValuesInt.AES_CCM_16_64_128:
case AlgorithmValuesInt.AES_CCM_64_64_128:
cbitKey = 128;
cbitTag = 64;
break;
case AlgorithmValuesInt.AES_CCM_16_128_128:
case AlgorithmValuesInt.AES_CCM_64_128_128:
cbitKey = 128;
cbitTag = 128;
break;
case AlgorithmValuesInt.AES_CCM_16_64_256:
case AlgorithmValuesInt.AES_CCM_64_64_256:
cbitKey = 256;
cbitTag = 64;
break;
case AlgorithmValuesInt.AES_CCM_16_128_256:
case AlgorithmValuesInt.AES_CCM_64_128_256:
cbitKey = 256;
cbitTag = 128;
break;
default:
throw new CoseException("Unsupported algorithm: " + alg);
}
switch ((AlgorithmValuesInt)alg.AsInt32())
{
case AlgorithmValuesInt.AES_CCM_16_64_128:
case AlgorithmValuesInt.AES_CCM_16_64_256:
case AlgorithmValuesInt.AES_CCM_16_128_128:
case AlgorithmValuesInt.AES_CCM_16_128_256:
cbIV = 15 - 2;
break;
case AlgorithmValuesInt.AES_CCM_64_64_128:
case AlgorithmValuesInt.AES_CCM_64_64_256:
case AlgorithmValuesInt.AES_CCM_64_128_256:
case AlgorithmValuesInt.AES_CCM_64_128_128:
cbIV = 15 - 8;
break;
default:
throw new CoseException("Unsupported algorithm: " + alg);
}
// The requirements from JWA
byte[] IV = new byte[cbIV];
CBORObject cbor = FindAttribute(HeaderKeys.IV);
if (cbor != null)
{
if (cbor.Type != CBORType.ByteString)
{
throw new CoseException("IV is incorrectly formed.");
}
if (cbor.GetByteString().Length > IV.Length)
{
throw new CoseException("IV is too long.");
}
Array.Copy(cbor.GetByteString(), 0, IV, 0, IV.Length);
}
else
{
s_PRNG.NextBytes(IV);
AddAttribute(HeaderKeys.IV, CBORObject.FromObject(IV), UNPROTECTED);
}
if (K == null)
{
throw new CoseException("Internal error");
}
if (K.Length != cbitKey / 8)
{
throw new CoseException("Incorrect key length");
}
ContentKey = new KeyParameter(K);
// Build the object to be hashed
AeadParameters parameters = new AeadParameters(ContentKey, cbitTag, IV, getAADBytes());
cipher.Init(false, parameters);
byte[] C = new byte[cipher.GetOutputSize(RgbEncrypted.Length)];
int len = cipher.ProcessBytes(RgbEncrypted, 0, RgbEncrypted.Length, C, 0);
len += cipher.DoFinal(C, len);
rgbContent = C;
}