private static readonly byte[] DefaultIV = { 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6 }; // http://www.ietf.org/rfc/rfc3394.txt (see 2.2.3)
public static byte[] Wrap(byte[] cek, byte[] kek)
{
Ensure.MinBitSize(cek, 128, "AesKeyWrap.Wrap() expects content length not less than 128 bits, but was {0}", cek.Length * 8);
Ensure.Divisible(cek.Length, 8, "AesKeyWrap.Wrap() expects content length to be divisable by 8, but was given a content of {0} bit size.", cek.Length * 8);
// 1) Initialize variables
byte[] a = DefaultIV; // Set A = IV, an initial value
byte[][] r = Arrays.Slice(cek, 8); // For i = 1 to n
// R[0][i] = P[i]
long n = r.Length;
// 2) Calculate intermediate values.
for (long j = 0; j < 6; j++) // For j = 0 to 5
{
for (long i = 0; i < n; i++) // For i=1 to n
{
long t = n * j + i + 1;
byte[] b = AesEnc(kek, Arrays.Concat(a, r[i])); // B=AES(K, A | R[i])
a = Arrays.FirstHalf(b); // A=MSB(64,B) ^ t where t = (n*j)+i
r[i] = Arrays.SecondHalf(b); // R[i] = LSB(64, B)
a = Arrays.Xor(a, t);
}
}
// 3) Output the results
byte[][] c = new byte[n + 1][];
c[0] = a; // Set C[0] = A
for (long i = 1; i <= n; i++) // For i = 1 to n
{
c[i] = r[i - 1]; // C[i] = R[i]
}
return(Arrays.Concat(c));
}
public static byte[] Wrap(byte[] cek, byte[] kek)
{
Ensure.MinBitSize(cek, 128, "AesKeyWrap.Wrap() expects content length not less than 128 bits, but was {0}", new object[] { (int)cek.Length * 8 });
Ensure.Divisible((int)cek.Length, 8, "AesKeyWrap.Wrap() expects content length to be divisable by 8, but was given a content of {0} bit size.", new object[] { (int)cek.Length * 8 });
byte[] defaultIV = AesKeyWrap.DefaultIV;
byte[][] numArray = Arrays.Slice(cek, 8);
long length = (long)((int)numArray.Length);
for (long i = (long)0; i < (long)6; i += (long)1)
{
for (long j = (long)0; j < length; j += (long)1)
{
long num = length * i + j + (long)1;
byte[] numArray1 = AesKeyWrap.AesEnc(kek, Arrays.Concat(new byte[][] { defaultIV, numArray[checked (j)] }));
defaultIV = Arrays.FirstHalf(numArray1);
numArray[checked (j)] = Arrays.SecondHalf(numArray1);
defaultIV = Arrays.Xor(defaultIV, num);
}
}
byte[][] numArray2 = new byte[checked (length + 1)][];
numArray2[0] = defaultIV;
for (long k = (long)1; k <= length; k += (long)1)
{
numArray2[checked (k)] = numArray[checked (k - (long)1)];
}
return(Arrays.Concat(numArray2));
}
public byte[][] WrapNewKey(int cekSizeBits, object key, IDictionary <string, object> header)
{
var sharedPassphrase = Ensure.Type <string>(key, "Pbse2HmacShaKeyManagementWithAesKeyWrap management algorithm expectes key to be string.");
byte[] sharedKey = Encoding.UTF8.GetBytes(sharedPassphrase);
byte[] algId = Encoding.UTF8.GetBytes((string)header["alg"]);
int iterationCount = 8192;
byte[] saltInput = Arrays.Random(96); //12 bytes
header["p2c"] = iterationCount;
header["p2s"] = Base64Url.Encode(saltInput);
byte[] salt = Arrays.Concat(algId, Arrays.Zero, saltInput);
byte[] kek;
using (var prf = PRF)
{
kek = PBKDF2.DeriveKey(sharedKey, salt, iterationCount, keyLengthBits, prf);
}
return(aesKW.WrapNewKey(cekSizeBits, kek, header));
}
public byte[] Unwrap(byte[] encryptedCek, object key, int cekSizeBits, IDictionary <string, object> header)
{
var sharedPassphrase = Ensure.Type <string>(key, "Pbse2HmacShaKeyManagementWithAesKeyWrap management algorithm expectes key to be string.");
byte[] sharedKey = Encoding.UTF8.GetBytes(sharedPassphrase);
Ensure.Contains(header, new[] { "p2c" }, "Pbse2HmacShaKeyManagementWithAesKeyWrap algorithm expects 'p2c' param in JWT header, but was not found");
Ensure.Contains(header, new[] { "p2s" }, "Pbse2HmacShaKeyManagementWithAesKeyWrap algorithm expects 'p2s' param in JWT header, but was not found");
byte[] algId = Encoding.UTF8.GetBytes((string)header["alg"]);
int iterationCount = Convert.ToInt32(header["p2c"]);
byte[] saltInput = Base64Url.Decode((string)header["p2s"]);
byte[] salt = Arrays.Concat(algId, Arrays.Zero, saltInput);
byte[] kek;
using (var prf = PRF)
{
kek = PBKDF2.DeriveKey(sharedKey, salt, iterationCount, keyLengthBits, prf);
}
return(aesKW.Unwrap(encryptedCek, kek, cekSizeBits, header));
}
public static byte[] Unwrap(byte[] encryptedCek, byte[] kek)
{
Ensure.MinBitSize(encryptedCek, 128, "AesKeyWrap.Unwrap() expects content length not less than 128 bits, but was {0}", new object[] { (int)encryptedCek.Length * 8 });
Ensure.Divisible((int)encryptedCek.Length, 8, "AesKeyWrap.Unwrap() expects content length to be divisable by 8, but was given a content of {0} bit size.", new object[] { (int)encryptedCek.Length * 8 });
byte[][] numArray = Arrays.Slice(encryptedCek, 8);
byte[] numArray1 = numArray[0];
byte[][] numArray2 = new byte[(int)numArray.Length - 1][];
for (int i = 1; i < (int)numArray.Length; i++)
{
numArray2[i - 1] = numArray[i];
}
long length = (long)((int)numArray2.Length);
for (long j = (long)5; j >= (long)0; j -= (long)1)
{
for (long k = length - (long)1; k >= (long)0; k -= (long)1)
{
long num = length * j + k + (long)1;
numArray1 = Arrays.Xor(numArray1, num);
byte[] numArray3 = AesKeyWrap.AesDec(kek, Arrays.Concat(new byte[][] { numArray1, numArray2[checked (k)] }));
numArray1 = Arrays.FirstHalf(numArray3);
numArray2[checked (k)] = Arrays.SecondHalf(numArray3);
}
}
if (!Arrays.ConstantTimeEquals(AesKeyWrap.DefaultIV, numArray1))
{
throw new IntegrityException("AesKeyWrap integrity check failed.");
}
return(Arrays.Concat(numArray2));
}
private static byte[] securedInput(byte[] header, byte[] payload, bool b64)
{
return(b64
? Encoding.UTF8.GetBytes(Compact.Serialize(header, payload))
: Arrays.Concat(Encoding.UTF8.GetBytes(Compact.Serialize(header)),
Encoding.UTF8.GetBytes("."),
payload));
}
private byte[] ComputeAuthTag(byte[] aad, byte[] iv, byte[] cipherText, byte[] hmacKey)
{
byte[] al = Arrays.LongToBytes(aad.Length * 8);
byte[] hmacInput = Arrays.Concat(aad, iv, cipherText, al);
byte[] hmac = hashAlgorithm.Sign(hmacInput, hmacKey);
return(Arrays.FirstHalf(hmac));
}
private static byte[] F(byte[] salt, int iterationCount, int blockIndex, HMAC prf)
{
byte[] numArray = prf.ComputeHash(Arrays.Concat(new byte[][] { salt, Arrays.IntToBytes(blockIndex) }));
byte[] numArray1 = numArray;
for (int i = 2; i <= iterationCount; i++)
{
numArray = prf.ComputeHash(numArray);
numArray1 = Arrays.Xor(numArray1, numArray);
}
return(numArray1);
}
private byte[] DeriveKey(IDictionary <string, object> header, int cekSizeBits, CngKey externalPublicKey, CngKey privateKey)
{
byte[] bytes = Encoding.UTF8.GetBytes((string)header[this.algIdHeader]);
byte[] numArray = (header.ContainsKey("apv") ? Base64Url.Decode((string)header["apv"]) : Arrays.Empty);
byte[] numArray1 = (header.ContainsKey("apu") ? Base64Url.Decode((string)header["apu"]) : Arrays.Empty);
byte[] numArray2 = Arrays.Concat(new byte[][] { Arrays.IntToBytes((int)bytes.Length), bytes });
byte[] numArray3 = Arrays.Concat(new byte[][] { Arrays.IntToBytes((int)numArray1.Length), numArray1 });
byte[] numArray4 = Arrays.Concat(new byte[][] { Arrays.IntToBytes((int)numArray.Length), numArray });
byte[] bytes1 = Arrays.IntToBytes(cekSizeBits);
return(ConcatKDF.DeriveKey(externalPublicKey, privateKey, cekSizeBits, numArray2, numArray4, numArray3, bytes1));
}
private byte[] DeriveKey(IDictionary <string, object> header, int cekSizeBits, CngKey externalPublicKey, CngKey privateKey)
{
byte[] enc = Encoding.UTF8.GetBytes((string)header[algIdHeader]);
byte[] apv = header.ContainsKey("apv") ? Base64Url.Decode((string)header["apv"]) : Arrays.Empty;
byte[] apu = header.ContainsKey("apu") ? Base64Url.Decode((string)header["apu"]) : Arrays.Empty;
byte[] algorithmId = Arrays.Concat(Arrays.IntToBytes(enc.Length), enc);
byte[] partyUInfo = Arrays.Concat(Arrays.IntToBytes(apu.Length), apu);
byte[] partyVInfo = Arrays.Concat(Arrays.IntToBytes(apv.Length), apv);
byte[] suppPubInfo = Arrays.IntToBytes(cekSizeBits);
return(ConcatKDF.DeriveKey(externalPublicKey, privateKey, cekSizeBits, algorithmId, partyVInfo, partyUInfo, suppPubInfo));
}
private static byte[] F(byte[] salt, int iterationCount, int blockIndex, HMAC prf)
{
byte[] U = prf.ComputeHash(Arrays.Concat(salt, Arrays.IntToBytes(blockIndex))); // U_1 = PRF (P, S || INT (i))
byte[] result = U;
for (int i = 2; i <= iterationCount; i++)
{
U = prf.ComputeHash(U); // U_c = PRF (P, U_{c-1}) .
result = Arrays.Xor(result, U); // U_1 \xor U_2 \xor ... \xor U_c
}
return(result);
}
private static IntPtr ImportKey(IntPtr hAlg, byte[] key, out IntPtr hKey)
{
int num = BitConverter.ToInt32(AesGcm.GetProperty(hAlg, BCrypt.BCRYPT_OBJECT_LENGTH), 0);
IntPtr intPtr = Marshal.AllocHGlobal(num);
byte[] numArray = Arrays.Concat(new byte[][] { BCrypt.BCRYPT_KEY_DATA_BLOB_MAGIC, BitConverter.GetBytes(1), BitConverter.GetBytes((int)key.Length), key });
uint num1 = BCrypt.BCryptImportKey(hAlg, IntPtr.Zero, BCrypt.BCRYPT_KEY_DATA_BLOB, out hKey, intPtr, num, numArray, (int)numArray.Length, 0);
if (num1 != 0)
{
throw new CryptographicException(string.Format("BCrypt.BCryptImportKey() failed with status code:{0}", num1));
}
return(intPtr);
}
private static IntPtr ImportKey(IntPtr hAlg, byte[] key, out IntPtr hKey)
{
byte[] objLength = GetProperty(hAlg, BCrypt.BCRYPT_OBJECT_LENGTH);
int keyDataSize = BitConverter.ToInt32(objLength, 0);
IntPtr keyDataBuffer = Marshal.AllocHGlobal(keyDataSize);
byte[] keyBlob = Arrays.Concat(BCrypt.BCRYPT_KEY_DATA_BLOB_MAGIC, BitConverter.GetBytes(0x1), BitConverter.GetBytes(key.Length), key);
uint status = BCrypt.BCryptImportKey(hAlg, IntPtr.Zero, BCrypt.BCRYPT_KEY_DATA_BLOB, out hKey, keyDataBuffer, keyDataSize, keyBlob, keyBlob.Length, 0x0);
if (status != BCrypt.ERROR_SUCCESS)
{
throw new CryptographicException(string.Format("BCrypt.BCryptImportKey() failed with status code:{0}", status));
}
return(keyDataBuffer);
}
public byte[] Unwrap(byte[] encryptedCek, object key, int cekSizeBits, IDictionary <string, object> header)
{
byte[] numArray;
string str = Ensure.Type <string>(key, "Pbse2HmacShaKeyManagementWithAesKeyWrap management algorithm expectes key to be string.", new object[0]);
byte[] bytes = Encoding.UTF8.GetBytes(str);
Ensure.Contains(header, new string[] { "p2c" }, "Pbse2HmacShaKeyManagementWithAesKeyWrap algorithm expects 'p2c' param in JWT header, but was not found", new object[0]);
Ensure.Contains(header, new string[] { "p2s" }, "Pbse2HmacShaKeyManagementWithAesKeyWrap algorithm expects 'p2s' param in JWT header, but was not found", new object[0]);
byte[] bytes1 = Encoding.UTF8.GetBytes((string)header["alg"]);
int num = Convert.ToInt32(header["p2c"]);
byte[] numArray1 = Base64Url.Decode((string)header["p2s"]);
byte[] numArray2 = Arrays.Concat(new byte[][] { bytes1, Arrays.Zero, numArray1 });
using (HMAC pRF = this.PRF)
{
numArray = PBKDF2.DeriveKey(bytes, numArray2, num, this.keyLengthBits, pRF);
}
return(this.aesKW.Unwrap(encryptedCek, numArray, cekSizeBits, header));
}
public byte[][] WrapNewKey(int cekSizeBits, object key, IDictionary <string, object> header)
{
byte[] numArray;
string str = Ensure.Type <string>(key, "Pbse2HmacShaKeyManagementWithAesKeyWrap management algorithm expectes key to be string.", new object[0]);
byte[] bytes = Encoding.UTF8.GetBytes(str);
byte[] bytes1 = Encoding.UTF8.GetBytes((string)header["alg"]);
int num = 8192;
byte[] numArray1 = Arrays.Random(96);
header["p2c"] = num;
header["p2s"] = Base64Url.Encode(numArray1);
byte[] numArray2 = Arrays.Concat(new byte[][] { bytes1, Arrays.Zero, numArray1 });
using (HMAC pRF = this.PRF)
{
numArray = PBKDF2.DeriveKey(bytes, numArray2, num, this.keyLengthBits, pRF);
}
return(this.aesKW.WrapNewKey(cekSizeBits, numArray, header));
}
public static byte[] DeriveKey(byte[] password, byte[] salt, int iterationCount, int keyBitLength, HMAC prf)
{
prf.Key = password;
ulong num = unchecked ((ulong)-1);
object[] objArray = new object[] { keyBitLength };
Ensure.MaxValue(keyBitLength, (long)num, "PBKDF2 expect derived key size to be not more that (2^32-1) bits, but was requested {0} bits.", objArray);
int hashSize = prf.HashSize / 8;
int num1 = keyBitLength / 8;
int num2 = (int)Math.Ceiling((double)num1 / (double)hashSize);
int num3 = num1 - (num2 - 1) * hashSize;
byte[][] numArray = new byte[num2][];
for (int i = 0; i < num2; i++)
{
numArray[i] = PBKDF2.F(salt, iterationCount, i + 1, prf);
}
numArray[num2 - 1] = Arrays.LeftmostBits(numArray[num2 - 1], num3 * 8);
return(Arrays.Concat(numArray));
}
static byte[] DeriveKey(IDictionary <string, object> header, int cekSizeBits, ECPublicKeyParameters externalPublicKey,
ECPrivateKeyParameters ephemeralPrvKey)
{
var z = EcdhKeyAgreementZ(externalPublicKey, ephemeralPrvKey);
var kdfGen = new ConcatenationKdfGenerator(new Sha256Digest());
byte[] algId = Encoding.ASCII.GetBytes(header["enc"].ToString());
byte[] apu = header.ContainsKey("apu") ? Base64Url.Decode((string)header["apu"]) : Arrays.Empty;
byte[] apv = header.ContainsKey("apv") ? Base64Url.Decode((string)header["apv"]) : Arrays.Empty;
byte[] kdl = CalcBeLengthArray(cekSizeBits);
var otherInfo = Arrays.Concat(PrependLength(algId), PrependLength(apu), PrependLength(apv), kdl);
//Console.Out.WriteLine($"otherInfo={VAU.ByteArrayToHexString(otherInfo)}");
kdfGen.Init(new KdfParameters(z, otherInfo));
byte[] secretKeyBytes = new byte[32];
kdfGen.GenerateBytes(secretKeyBytes, 0, secretKeyBytes.Length);
return(secretKeyBytes);
}
public static byte[] Unwrap(byte[] encryptedCek, byte[] kek)
{
Ensure.MinBitSize(encryptedCek, 128, "AesKeyWrap.Unwrap() expects content length not less than 128 bits, but was {0}", encryptedCek.Length * 8);
Ensure.Divisible(encryptedCek.Length, 8, "AesKeyWrap.Unwrap() expects content length to be divisable by 8, but was given a content of {0} bit size.", encryptedCek.Length * 8);
// 1) Initialize variables
byte[][] c = Arrays.Slice(encryptedCek, 8);
byte[] a = c[0]; // Set A = C[0]
byte[][] r = new byte[c.Length - 1][];
for (int i = 1; i < c.Length; i++) // For i = 1 to n
{
r[i - 1] = c[i]; // R[i] = C[i]
}
long n = r.Length;
// 2) Calculate intermediate values
for (long j = 5; j >= 0; j--) // For j = 5 to 0
{
for (long i = n - 1; i >= 0; i--) // For i = n to 1
{
long t = n * j + i + 1;
a = Arrays.Xor(a, t);
byte[] B = AesDec(kek, Arrays.Concat(a, r[i])); // B = AES-1(K, (A ^ t) | R[i]) where t = n*j+i
a = Arrays.FirstHalf(B); // A = MSB(64, B)
r[i] = Arrays.SecondHalf(B); // R[i] = LSB(64, B)
}
}
// 3) Output the results
if (!Arrays.ConstantTimeEquals(DefaultIV, a)) // If A is an appropriate initial value
{
throw new IntegrityException("AesKeyWrap integrity check failed.");
}
// For i = 1 to n
return(Arrays.Concat(r)); // P[i] = R[i]
}
/// <summary>
/// Implements RFC2898 Password Based Key Derivation Function #2
/// </summary>
/// <param name="password">password to be used as hash key</param>
/// <param name="salt">salt</param>
/// <param name="iterationCount">number of iterations to perform</param>
/// <param name="keyBitLength">desired key length in bits to detive</param>
/// <param name="prf">Pseudo Random Function, HMAC will be inited with key equal to given password</param>
/// <returns></returns>
public static byte[] DeriveKey(byte[] password, byte[] salt, int iterationCount, int keyBitLength, HMAC prf)
{
prf.Key = password;
// 1. If dkLen > (2^32 - 1) * hLen, output "derived key too long" and stop.
Ensure.MaxValue(keyBitLength, 4294967295, "PBKDF2 expect derived key size to be not more that (2^32-1) bits, but was requested {0} bits.", keyBitLength);
int hLen = prf.HashSize / 8; //size of mac in bytes
int dkLen = keyBitLength / 8; //size of derived key in bytes
int l = (int)Math.Ceiling(dkLen / (double)hLen); // l = CEIL (dkLen / hLen) ,
int r = dkLen - (l - 1) * hLen; // r = dkLen - (l - 1) * hLen .
byte[][] T = new byte[l][];
for (int i = 0; i < l; i++)
{
T[i] = F(salt, iterationCount, i + 1, prf); // T_l = F (P, S, c, l)
}
T[l - 1] = Arrays.LeftmostBits(T[l - 1], r * 8); //truncate last block to r bits
return(Arrays.Concat(T)); // DK = T_1 || T_2 || ... || T_l<0..r-1>
}
private byte[] ComputeAuthTag(byte[] aad, byte[] iv, byte[] cipherText, byte[] hmacKey)
{
byte[] bytes = Arrays.LongToBytes((long)((int)aad.Length * 8));
byte[] numArray = Arrays.Concat(new byte[][] { aad, iv, cipherText, bytes });
return(Arrays.FirstHalf(this.hashAlgorithm.Sign(numArray, hmacKey)));
}
static byte[] PrependLength(byte[] data)
{
return(Arrays.Concat(CalcBeLengthArray(data.Length), data));
}