private void Decrypt()
{
if (m_pbData.Length == 0)
{
return;
}
if (m_mp == PbMemProt.ProtectedMemory)
{
ProtectedMemory.Unprotect(m_pbData, MemoryProtectionScope.SameProcess);
}
else if (m_mp == PbMemProt.ChaCha20)
{
byte[] pbIV = new byte[12];
MemUtil.UInt64ToBytesEx((ulong)m_lID, pbIV, 4);
using (ChaCha20Cipher c = new ChaCha20Cipher(g_pbKey32, pbIV, true))
{
c.Decrypt(m_pbData, 0, m_pbData.Length);
}
}
else if (m_mp == PbMemProt.ExtCrypt)
{
m_fExtCrypt(m_pbData, PbCryptFlags.Decrypt, m_lID);
}
else
{
Debug.Assert(m_mp == PbMemProt.None);
}
m_mp = PbMemProt.None;
}
private void Encrypt()
{
Debug.Assert(m_mp == PbMemProt.None);
// Nothing to do if caller didn't request protection
if (!m_bProtected)
{
return;
}
// ProtectedMemory.Protect throws for data size == 0
if (m_pbData.Length == 0)
{
return;
}
PbCryptDelegate f = g_fExtCrypt;
if (f != null)
{
f(m_pbData, PbCryptFlags.Encrypt, m_lID);
m_fExtCrypt = f;
m_mp = PbMemProt.ExtCrypt;
return;
}
if (ProtectedBinary.ProtectedMemorySupported)
{
#if NETSTANDARD2_0
m_pbData = CryptoUtil.EncryptBytesAES(m_pbData,
CryptoUtil.SharedSecret);
#else
ProtectedMemory.Protect(m_pbData, MemoryProtectionScope.SameProcess);
#endif
m_mp = PbMemProt.ProtectedMemory;
return;
}
byte[] pbKey32 = g_pbKey32;
if (pbKey32 == null)
{
pbKey32 = CryptoRandom.Instance.GetRandomBytes(32);
byte[] pbUpd = Interlocked.Exchange <byte[]>(ref g_pbKey32, pbKey32);
if (pbUpd != null)
{
pbKey32 = pbUpd;
}
}
byte[] pbIV = new byte[12];
MemUtil.UInt64ToBytesEx((ulong)m_lID, pbIV, 4);
using (ChaCha20Cipher c = new ChaCha20Cipher(pbKey32, pbIV, true))
{
c.Encrypt(m_pbData, 0, m_pbData.Length);
}
m_mp = PbMemProt.ChaCha20;
}
/// <summary>
/// Creates a cipher instance (<see cref="ChaCha20Cipher"/> or <see cref="Salsa20Cipher"/> (KeePass older as 2.35)) with the nonce and the pin as key.
/// </summary>
/// <param name="pin">The pin to use as key.</param>
/// <param name="nonce">The nonce to use as IV.</param>
/// <returns>The cipher instance.</returns>
private static CtrBlockCipher CreateCipher(byte[] pin, byte[] nonce)
{
Contract.Requires(pin != null);
Contract.Requires(nonce != null);
Contract.Ensures(Contract.Result <ChaCha20Cipher>() != null);
var key = new byte[32];
using (var h = new SHA512Managed())
{
var hashBytes = h.ComputeHash(pin);
Array.Copy(hashBytes, key, 32);
MemUtil.ZeroByteArray(hashBytes);
}
CtrBlockCipher cipher;
if (nonce.Length == 12 /*>= KeePass 2.35*/)
{
cipher = new ChaCha20Cipher(key, nonce, false);
}
else
{
cipher = new Salsa20Cipher(key, nonce);
}
MemUtil.ZeroByteArray(key);
return(cipher);
}
private void Encrypt()
{
Debug.Assert(m_mp == PbMemProt.None);
// Nothing to do if caller didn't request protection
if (!m_bProtected)
{
return;
}
// ProtectedMemory.Protect throws for data size == 0
if (m_pbData.Length == 0)
{
return;
}
PbCryptDelegate f = g_fExtCrypt;
if (f != null)
{
f(m_pbData, PbCryptFlags.Encrypt, m_lID);
m_fExtCrypt = f;
m_mp = PbMemProt.ExtCrypt;
return;
}
#if !KPCLib
// ProtectedMemory is not supported on Android, iOS and UWP
if (ProtectedBinary.ProtectedMemorySupported)
{
ProtectedMemory.Protect(m_pbData, MemoryProtectionScope.SameProcess);
m_mp = PbMemProt.ProtectedMemory;
return;
}
#endif // KPCLib
byte[] pbKey32 = g_pbKey32;
if (pbKey32 == null)
{
pbKey32 = GetRandom32();
byte[] pbUpd = Interlocked.Exchange <byte[]>(ref g_pbKey32, pbKey32);
if (pbUpd != null)
{
pbKey32 = pbUpd;
}
}
byte[] pbIV = new byte[12];
MemUtil.UInt64ToBytesEx((ulong)m_lID, pbIV, 4);
using (ChaCha20Cipher c = new ChaCha20Cipher(pbKey32, pbIV, true))
{
c.Encrypt(m_pbData, 0, m_pbData.Length);
}
m_mp = PbMemProt.ChaCha20;
}
private void Decrypt()
{
if (m_pbData.Length == 0)
{
return;
}
if (m_mp == PbMemProt.ProtectedMemory)
{
#if NETSTANDARD2_0
var unprotectedData = CryptoUtil.UnprotectData(m_pbData, null, DataProtectionScope.CurrentUser);
Array.Clear(m_pbData, 0, m_pbData.Length);
m_pbData = unprotectedData;
#else
ProtectedMemory.Unprotect(m_pbData, MemoryProtectionScope.SameProcess);
#endif
}
else if (m_mp == PbMemProt.ChaCha20)
{
byte[] pbIV = new byte[12];
MemUtil.UInt64ToBytesEx((ulong)m_lID, pbIV, 4);
using (ChaCha20Cipher c = new ChaCha20Cipher(g_pbKey32, pbIV, true))
{
c.Decrypt(m_pbData, 0, m_pbData.Length);
}
}
else if (m_mp == PbMemProt.ExtCrypt)
{
m_fExtCrypt(m_pbData, PbCryptFlags.Decrypt, m_lID);
}
else
{
Debug.Assert(m_mp == PbMemProt.None);
}
m_mp = PbMemProt.None;
}
public ISingleCipherTransform GetCipherTransformer()
{
if (m_SymAlgo == SymAlgoCode.AES256 || m_SymAlgo == SymAlgoCode.ThreeDES || m_SymAlgo == SymAlgoCode.Twofish)
{
SymmetricAlgorithm SymAlgo;
if (m_SymAlgo == SymAlgoCode.ThreeDES)
{
SymAlgo = new TripleDESCryptoServiceProvider
{
BlockSize = 64,
IV = m_IV,
KeySize = 192,
Key = m_Key,
Mode = CipherMode.CBC,
Padding = PaddingMode.None
};
}
else if (m_SymAlgo == SymAlgoCode.AES256)
{
SymAlgo = new RijndaelManaged
{
BlockSize = 128,
IV = m_IV,
KeySize = 256,
Key = m_Key,
Mode = CipherMode.CBC,
Padding = PaddingMode.None
}
}
;
else
{
SymAlgo = new TwofishManaged
{
BlockSize = 128,
IV = m_IV,
KeySize = 256,
Key = m_Key,
Mode = CipherMode.CBC,
Padding = PaddingMode.None
}
};
return(new CryptoTransformer(SymAlgo));
}
else if (m_SymAlgo == SymAlgoCode.ChaCha20 || m_SymAlgo == SymAlgoCode.Salsa20)
{
CtrBlockCipher c;
if (m_SymAlgo == SymAlgoCode.ChaCha20)
{
c = new ChaCha20Cipher(m_Key, m_IV);
}
else
{
c = new Salsa20Cipher(m_Key, m_IV);
}
return(new CtrBlockCipherTransformer(c));
}
throw new SecurityException("Invalid Algorithm");
}
public void TestChacha20Cipher()
{
// ======================================================
// Test vector from RFC 7539, section 2.3.2
var pbKey = new byte[32];
for (var i = 0; i < 32; ++i)
{
pbKey[i] = (byte)i;
}
var pbIV = new byte[12];
pbIV[3] = 0x09;
pbIV[7] = 0x4A;
var pbExpc = new byte[] {
0x10, 0xF1, 0xE7, 0xE4, 0xD1, 0x3B, 0x59, 0x15,
0x50, 0x0F, 0xDD, 0x1F, 0xA3, 0x20, 0x71, 0xC4,
0xC7, 0xD1, 0xF4, 0xC7, 0x33, 0xC0, 0x68, 0x03,
0x04, 0x22, 0xAA, 0x9A, 0xC3, 0xD4, 0x6C, 0x4E,
0xD2, 0x82, 0x64, 0x46, 0x07, 0x9F, 0xAA, 0x09,
0x14, 0xC2, 0xD7, 0x05, 0xD9, 0x8B, 0x02, 0xA2,
0xB5, 0x12, 0x9C, 0xD1, 0xDE, 0x16, 0x4E, 0xB9,
0xCB, 0xD0, 0x83, 0xE8, 0xA2, 0x50, 0x3C, 0x4E
};
var pb = new byte[64];
using (var chaCha20Cipher1 = new ChaCha20Cipher(pbKey, pbIV))
{
chaCha20Cipher1.Seek(64, SeekOrigin.Begin); // Skip first block
chaCha20Cipher1.Encrypt(pb, 0, pb.Length);
Assert.That(MemUtil.ArraysEqual(pb, pbExpc), Is.True);
}
#if DEBUG
// ======================================================
// Test vector from RFC 7539, section 2.4.2
pbIV[3] = 0;
pb = StrUtil.Utf8.GetBytes("Ladies and Gentlemen of the clas" +
@"s of '99: If I could offer you only one tip for " +
@"the future, sunscreen would be it.");
pbExpc = new byte[] {
0x6E, 0x2E, 0x35, 0x9A, 0x25, 0x68, 0xF9, 0x80,
0x41, 0xBA, 0x07, 0x28, 0xDD, 0x0D, 0x69, 0x81,
0xE9, 0x7E, 0x7A, 0xEC, 0x1D, 0x43, 0x60, 0xC2,
0x0A, 0x27, 0xAF, 0xCC, 0xFD, 0x9F, 0xAE, 0x0B,
0xF9, 0x1B, 0x65, 0xC5, 0x52, 0x47, 0x33, 0xAB,
0x8F, 0x59, 0x3D, 0xAB, 0xCD, 0x62, 0xB3, 0x57,
0x16, 0x39, 0xD6, 0x24, 0xE6, 0x51, 0x52, 0xAB,
0x8F, 0x53, 0x0C, 0x35, 0x9F, 0x08, 0x61, 0xD8,
0x07, 0xCA, 0x0D, 0xBF, 0x50, 0x0D, 0x6A, 0x61,
0x56, 0xA3, 0x8E, 0x08, 0x8A, 0x22, 0xB6, 0x5E,
0x52, 0xBC, 0x51, 0x4D, 0x16, 0xCC, 0xF8, 0x06,
0x81, 0x8C, 0xE9, 0x1A, 0xB7, 0x79, 0x37, 0x36,
0x5A, 0xF9, 0x0B, 0xBF, 0x74, 0xA3, 0x5B, 0xE6,
0xB4, 0x0B, 0x8E, 0xED, 0xF2, 0x78, 0x5E, 0x42,
0x87, 0x4D
};
var pb64 = new byte[64];
using (var chaCha20Cipher2 = new ChaCha20Cipher(pbKey, pbIV))
{
chaCha20Cipher2.Encrypt(pb64, 0, pb64.Length); // Skip first block
chaCha20Cipher2.Encrypt(pb, 0, pb.Length);
Assert.That(MemUtil.ArraysEqual(pb, pbExpc), Is.True);
}
// ======================================================
// Test vector from RFC 7539, appendix A.2 #2
Array.Clear(pbKey, 0, pbKey.Length);
pbKey[31] = 1;
Array.Clear(pbIV, 0, pbIV.Length);
pbIV[11] = 2;
pb = StrUtil.Utf8.GetBytes("Any submission to the IETF inten" +
"ded by the Contributor for publication as all or" +
" part of an IETF Internet-Draft or RFC and any s" +
"tatement made within the context of an IETF acti" +
"vity is considered an \"IETF Contribution\". Such " +
"statements include oral statements in IETF sessi" +
"ons, as well as written and electronic communica" +
"tions made at any time or place, which are addressed to");
pbExpc = MemUtil.HexStringToByteArray(
"A3FBF07DF3FA2FDE4F376CA23E82737041605D9F4F4F57BD8CFF2C1D4B7955EC" +
"2A97948BD3722915C8F3D337F7D370050E9E96D647B7C39F56E031CA5EB6250D" +
"4042E02785ECECFA4B4BB5E8EAD0440E20B6E8DB09D881A7C6132F420E527950" +
"42BDFA7773D8A9051447B3291CE1411C680465552AA6C405B7764D5E87BEA85A" +
"D00F8449ED8F72D0D662AB052691CA66424BC86D2DF80EA41F43ABF937D3259D" +
"C4B2D0DFB48A6C9139DDD7F76966E928E635553BA76C5C879D7B35D49EB2E62B" +
"0871CDAC638939E25E8A1E0EF9D5280FA8CA328B351C3C765989CBCF3DAA8B6C" +
"CC3AAF9F3979C92B3720FC88DC95ED84A1BE059C6499B9FDA236E7E818B04B0B" +
"C39C1E876B193BFE5569753F88128CC08AAA9B63D1A16F80EF2554D7189C411F" +
"5869CA52C5B83FA36FF216B9C1D30062BEBCFD2DC5BCE0911934FDA79A86F6E6" +
"98CED759C3FF9B6477338F3DA4F9CD8514EA9982CCAFB341B2384DD902F3D1AB" +
"7AC61DD29C6F21BA5B862F3730E37CFDC4FD806C22F221");
using (var msEnc = new MemoryStream())
{
using (var chaCha20Stream = new ChaCha20Stream(msEnc, true, pbKey, pbIV))
{
var r = CryptoRandom.NewWeakRandom();
r.NextBytes(pb64);
chaCha20Stream.Write(pb64, 0, pb64.Length); // Skip first block
var p = 0;
while (p < pb.Length)
{
var cb = r.Next(1, pb.Length - p + 1);
chaCha20Stream.Write(pb, p, cb);
p += cb;
}
Debug.Assert(p == pb.Length);
}
var pbEnc0 = msEnc.ToArray();
var pbEnc = MemUtil.Mid(pbEnc0, 64, pbEnc0.Length - 64);
Assert.That(MemUtil.ArraysEqual(pbEnc, pbExpc), Is.True);
using var msCT = new MemoryStream(pbEnc0, false);
using var cDec = new ChaCha20Stream(msCT, false, pbKey, pbIV);
var pbPT = MemUtil.Read(cDec, pbEnc0.Length);
Assert.That(cDec.ReadByte(), Is.LessThan(0));
Assert.That(MemUtil.ArraysEqual(MemUtil.Mid(pbPT, 0, 64), pb64), Is.True);
Assert.That(MemUtil.ArraysEqual(MemUtil.Mid(pbPT, 64, pbEnc.Length), pb), Is.True);
}
// ======================================================
// Test vector TC8 from RFC draft by J. Strombergson:
// https://tools.ietf.org/html/draft-strombergson-chacha-test-vectors-01
pbKey = new byte[] {
0xC4, 0x6E, 0xC1, 0xB1, 0x8C, 0xE8, 0xA8, 0x78,
0x72, 0x5A, 0x37, 0xE7, 0x80, 0xDF, 0xB7, 0x35,
0x1F, 0x68, 0xED, 0x2E, 0x19, 0x4C, 0x79, 0xFB,
0xC6, 0xAE, 0xBE, 0xE1, 0xA6, 0x67, 0x97, 0x5D
};
// The first 4 bytes are set to zero and a large counter
// is used; this makes the RFC 7539 version of ChaCha20
// compatible with the original specification by
// D. J. Bernstein.
pbIV = new byte[] { 0x00, 0x00, 0x00, 0x00,
0x1A, 0xDA, 0x31, 0xD5, 0xCF, 0x68, 0x82, 0x21 };
pb = new byte[128];
pbExpc = new byte[] {
0xF6, 0x3A, 0x89, 0xB7, 0x5C, 0x22, 0x71, 0xF9,
0x36, 0x88, 0x16, 0x54, 0x2B, 0xA5, 0x2F, 0x06,
0xED, 0x49, 0x24, 0x17, 0x92, 0x30, 0x2B, 0x00,
0xB5, 0xE8, 0xF8, 0x0A, 0xE9, 0xA4, 0x73, 0xAF,
0xC2, 0x5B, 0x21, 0x8F, 0x51, 0x9A, 0xF0, 0xFD,
0xD4, 0x06, 0x36, 0x2E, 0x8D, 0x69, 0xDE, 0x7F,
0x54, 0xC6, 0x04, 0xA6, 0xE0, 0x0F, 0x35, 0x3F,
0x11, 0x0F, 0x77, 0x1B, 0xDC, 0xA8, 0xAB, 0x92,
0xE5, 0xFB, 0xC3, 0x4E, 0x60, 0xA1, 0xD9, 0xA9,
0xDB, 0x17, 0x34, 0x5B, 0x0A, 0x40, 0x27, 0x36,
0x85, 0x3B, 0xF9, 0x10, 0xB0, 0x60, 0xBD, 0xF1,
0xF8, 0x97, 0xB6, 0x29, 0x0F, 0x01, 0xD1, 0x38,
0xAE, 0x2C, 0x4C, 0x90, 0x22, 0x5B, 0xA9, 0xEA,
0x14, 0xD5, 0x18, 0xF5, 0x59, 0x29, 0xDE, 0xA0,
0x98, 0xCA, 0x7A, 0x6C, 0xCF, 0xE6, 0x12, 0x27,
0x05, 0x3C, 0x84, 0xE4, 0x9A, 0x4A, 0x33, 0x32
};
using var c = new ChaCha20Cipher(pbKey, pbIV, true);
c.Decrypt(pb, 0, pb.Length);
Assert.That(MemUtil.ArraysEqual(pb, pbExpc), Is.True);
#endif
}
/// <summary>
/// Construct a new cryptographically secure random stream object.
/// </summary>
/// <param name="a">Algorithm to use.</param>
/// <param name="pbKey">Initialization key. Must not be <c>null</c> and
/// must contain at least 1 byte.</param>
public CryptoRandomStream(CrsAlgorithm a, byte[] pbKey)
{
if (pbKey == null)
{
Debug.Assert(false); throw new ArgumentNullException("pbKey");
}
int cbKey = pbKey.Length;
if (cbKey <= 0)
{
Debug.Assert(false); // Need at least one byte
throw new ArgumentOutOfRangeException("pbKey");
}
m_crsAlgorithm = a;
if (a == CrsAlgorithm.ChaCha20)
{
byte[] pbKey32 = new byte[32];
byte[] pbIV12 = new byte[12];
using (SHA512Managed h = new SHA512Managed())
{
byte[] pbHash = h.ComputeHash(pbKey);
Array.Copy(pbHash, pbKey32, 32);
Array.Copy(pbHash, 32, pbIV12, 0, 12);
MemUtil.ZeroByteArray(pbHash);
}
m_chacha20 = new ChaCha20Cipher(pbKey32, pbIV12, true);
}
else if (a == CrsAlgorithm.Salsa20)
{
byte[] pbKey32 = CryptoUtil.HashSha256(pbKey);
byte[] pbIV8 = new byte[8] {
0xE8, 0x30, 0x09, 0x4B,
0x97, 0x20, 0x5D, 0x2A
}; // Unique constant
m_salsa20 = new Salsa20Cipher(pbKey32, pbIV8);
}
else if (a == CrsAlgorithm.ArcFourVariant)
{
// Fill the state linearly
m_pbState = new byte[256];
for (int w = 0; w < 256; ++w)
{
m_pbState[w] = (byte)w;
}
unchecked
{
byte j = 0, t;
int inxKey = 0;
for (int w = 0; w < 256; ++w) // Key setup
{
j += (byte)(m_pbState[w] + pbKey[inxKey]);
t = m_pbState[0]; // Swap entries
m_pbState[0] = m_pbState[j];
m_pbState[j] = t;
++inxKey;
if (inxKey >= cbKey)
{
inxKey = 0;
}
}
}
GetRandomBytes(512); // Increases security, see cryptanalysis
}
else // Unknown algorithm
{
Debug.Assert(false);
throw new ArgumentOutOfRangeException("a");
}
}
