namespace com.hitrust.Security.Cryptography
{
    using com.hitrust.Security;
    using System;
    using System.Runtime.InteropServices;
    using System.Security.Cryptography;
    using System.Text;

    internal sealed class SymmetricKey : IDisposable
    {
        private static readonly byte[] ExponentOfOne = new byte[] { 
            7, 2, 0, 0, 0, 0xa4, 0, 0, 0x52, 0x53, 0x41, 50, 0, 4, 0, 0, 
            1, 0, 0, 0, 0x4b, 0x59, 0x4e, 0x26, 0xd0, 90, 0x33, 11, 0xbd, 0x5d, 0x44, 0x53, 
            0x19, 0xa3, 0x74, 0x8a, 0x1c, 0x90, 0x71, 0x75, 8, 0x41, 0x19, 0xf4, 0xbc, 0x92, 0x23, 4, 
            0x26, 0x67, 0x8d, 190, 0xe4, 0x6f, 0x74, 0x71, 0x47, 0x60, 0x60, 0x55, 0x1f, 0x72, 0x20, 0x79, 
            0xf2, 0x21, 0xab, 0x91, 0xc4, 0xc9, 0x5c, 180, 0x89, 0x67, 0x52, 0x10, 0x9c, 0x71, 0x52, 0x7b, 
            0xd4, 0x42, 0xae, 14, 0x93, 0xa6, 0xaf, 0x8d, 0x3a, 0x61, 0x70, 0x41, 0x98, 0xc3, 0x58, 220, 
            0xcf, 0x4c, 0xef, 0x3e, 0xc6, 0xf3, 0xe0, 180, 0xcd, 0xfb, 0xec, 0x81, 11, 0x7a, 0x75, 0x29, 
            0x7a, 190, 0x40, 0xf6, 0x4a, 0x3f, 0x40, 0xb7, 0x43, 240, 0x45, 0x3f, 150, 0xf1, 0x73, 0x2f, 
            0x71, 0xee, 0xa7, 0x70, 0x4d, 0xf9, 0x63, 0xb8, 0x52, 0x4c, 0xf1, 0x18, 0xf3, 60, 0x21, 0x13, 
            0x6a, 0x9a, 0x85, 0xb7, 0xa1, 0xfd, 0xb6, 0xa4, 0xf1, 0xeb, 3, 0xd6, 0x86, 5, 0x6a, 0x63, 
            0x93, 0xb2, 0xe7, 0xf9, 0x2a, 0x77, 9, 0xe4, 12, 0x90, 0x2d, 0x6a, 0xa2, 0xcd, 0x37, 11, 
            0xc0, 0xb6, 0x1c, 150, 0xc3, 0xa7, 0x57, 0xb1, 0x77, 0xf9, 0x55, 0x11, 0x8f, 0x44, 0x8d, 0x77, 
            0x31, 0xa7, 0x45, 0xe0, 0x8e, 0x42, 13, 0xe4, 7, 0x53, 0xf3, 0x5c, 0x8b, 0xc7, 0xd7, 0xb8, 
            100, 0x1f, 0xc0, 0xea, 0x6b, 0xf7, 0x9c, 0x91, 0x19, 0xad, 0x79, 0xe9, 0xde, 0xc3, 0x45, 0x66, 
            0xed, 0x3e, 30, 0x90, 0x40, 0x26, 0x8b, 1, 0x7f, 0xce, 5, 0xda, 0x97, 0x8b, 0xf8, 0x47, 
            0x3f, 0x4f, 0x74, 0xf2, 0x6d, 0x1f, 0x16, 0xd3, 0x25, 0x57, 0x2d, 0x30, 0x6f, 60, 0xe2, 0x41, 
            0x86, 0xc1, 0xc7, 0x33, 1, 0x54, 3, 5, 0xa4, 0x58, 0xcc, 0x88, 0x9c, 0x8d, 0x65, 0x5e, 
            2, 0x5c, 0x22, 200, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
            0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
            0, 0, 0, 0, 0xba, 0xf6, 0x8f, 0x2a, 0x9a, 0x4c, 0x3d, 210, 0xba, 0xd8, 0x77, 0x59, 
            0x41, 0x8a, 0xed, 0x3d, 130, 0x24, 6, 0xc1, 0x37, 0x79, 0x81, 5, 0xfb, 0x9c, 0x6c, 0x15, 
            190, 0x44, 0x5c, 0xb5, 0x16, 4, 0xc4, 0x4e, 0x9d, 0x89, 0xef, 0xf1, 0x15, 0x26, 0x19, 0x16, 
            0x3e, 0xdd, 0xac, 0x4f, 0xe1, 170, 0x44, 0x7b, 160, 0xc5, 0xe9, 0x93, 0xc1, 0x34, 0x15, 0x67, 
            0x69, 0x2d, 0xc3, 0x83, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
            0, 0, 0, 0
         };
        private int m_ExponentOfOne;
        private int m_Handle;
        private bool m_OwnsProvider;
        private PaddingMode m_PaddingMode;
        private int m_Provider;

        private SymmetricKey(CryptoProvider provider) : this(false)
        {
            this.m_Provider = 0;
            if (((SspiProvider.CryptAcquireContext(ref this.m_Provider, IntPtr.Zero, null, (int) provider, 8) == 0) && (Marshal.GetLastWin32Error() == -2146893809)) && (SspiProvider.CryptAcquireContext(ref this.m_Provider, IntPtr.Zero, null, (int) provider, 0) == 0))
            {
                throw new SecurityException("Cannot acquire crypto service provider.");
            }
            this.m_ExponentOfOne = this.CreateExponentOfOneKey();
            this.m_PaddingMode = PaddingMode.None;
        }

        private SymmetricKey(bool ownsProvider)
        {
            this.m_OwnsProvider = ownsProvider;
        }

        public SymmetricKey(CryptoProvider provider, CryptoAlgorithm algorithm) : this(provider)
        {
            this.m_Handle = 0;
            if (SspiProvider.CryptGenKey(this.m_Provider, new IntPtr((int) algorithm), 1, ref this.m_Handle) == 0)
            {
                throw new SecurityException("Cannot generate session key.");
            }
        }

        public SymmetricKey(CryptoProvider provider, CryptoAlgorithm algorithm, byte[] buffer) : this(provider)
        {
            if (buffer == null)
            {
                throw new ArgumentNullException();
            }
            this.m_Handle = this.KeyFromBytes(this.m_Provider, algorithm, buffer);
        }

        internal SymmetricKey(int provider, int key, bool ownsProvider) : this(ownsProvider)
        {
            if ((key == 0) || (provider == 0))
            {
                throw new ArgumentNullException();
            }
            this.m_Provider = provider;
            this.m_Handle = key;
            this.m_PaddingMode = PaddingMode.None;
        }

        private int CreateDynamicExponentOfOneKey()
        {
            int hPrivateKey = 0;
            int dwKeyBlob = 0;
            IntPtr keyblob = IntPtr.Zero;
            try
            {
                int i;
                if (SspiProvider.CryptGenKey(this.m_Provider, new IntPtr(1), 1, ref hPrivateKey) == 0)
                {
                    throw new SecurityException("Cannot generate key pair.");
                }
                if (SspiProvider.CryptExportKey(hPrivateKey, 0, 7, 0, IntPtr.Zero, ref dwKeyBlob) == 0)
                {
                    throw new SecurityException("Cannot export generated key.");
                }
                keyblob = Marshal.AllocHGlobal(dwKeyBlob);
                if (SspiProvider.CryptExportKey(hPrivateKey, 0, 7, 0, keyblob, ref dwKeyBlob) == 0)
                {
                    throw new SecurityException("Cannot export generated key.");
                }
                SspiProvider.CryptDestroyKey(hPrivateKey);
                hPrivateKey = 0;
                int dwBitLen = Marshal.ReadInt32(keyblob, 12);
                int offset = 0x10;
                for (i = 0; i < 4; i++)
                {
                    if (i == 0)
                    {
                        Marshal.WriteByte(keyblob, offset, 1);
                    }
                    else
                    {
                        Marshal.WriteByte(keyblob, offset + i, 0);
                    }
                }
                offset += 4;
                offset += dwBitLen / 8;
                offset += dwBitLen / 0x10;
                offset += dwBitLen / 0x10;
                for (i = 0; i < (dwBitLen / 0x10); i++)
                {
                    if (i == 0)
                    {
                        Marshal.WriteByte(keyblob, offset, 1);
                    }
                    else
                    {
                        Marshal.WriteByte(keyblob, offset + i, 0);
                    }
                }
                offset += dwBitLen / 0x10;
                for (i = 0; i < (dwBitLen / 0x10); i++)
                {
                    if (i == 0)
                    {
                        Marshal.WriteByte(keyblob, offset, 1);
                    }
                    else
                    {
                        Marshal.WriteByte(keyblob, offset + i, 0);
                    }
                }
                offset += dwBitLen / 0x10;
                offset += dwBitLen / 0x10;
                for (i = 0; i < (dwBitLen / 8); i++)
                {
                    if (i == 0)
                    {
                        Marshal.WriteByte(keyblob, offset, 1);
                    }
                    else
                    {
                        Marshal.WriteByte(keyblob, offset + i, 0);
                    }
                }
                if (SspiProvider.CryptImportKey(this.m_Provider, keyblob, dwKeyBlob, 0, 1, ref hPrivateKey) == 0)
                {
                    throw new SecurityException("Could not import modified key.");
                }
            }
            catch (Exception e)
            {
                if (hPrivateKey != 0)
                {
                    SspiProvider.CryptDestroyKey(hPrivateKey);
                }
                throw e;
            }
            finally
            {
                if (keyblob != IntPtr.Zero)
                {
                    Marshal.FreeHGlobal(keyblob);
                }
            }
            return hPrivateKey;
        }

        private int CreateExponentOfOneKey()
        {
            try
            {
                return this.CreateStaticExponentOfOneKey();
            }
            catch
            {
                return this.CreateDynamicExponentOfOneKey();
            }
        }

        private int CreateStaticExponentOfOneKey()
        {
            int hPrivateKey = 0;
            if (SspiProvider.CryptImportKey(this.m_Provider, ExponentOfOne, ExponentOfOne.Length, 0, 1, ref hPrivateKey) == 0)
            {
                throw new SecurityException("Could not import modified key.");
            }
            return hPrivateKey;
        }

        public void Dispose()
        {
            if (this.m_Handle != 0)
            {
                SspiProvider.CryptDestroyKey(this.m_Handle);
            }
            if (this.m_ExponentOfOne != 0)
            {
                SspiProvider.CryptDestroyKey(this.m_ExponentOfOne);
            }
            if (this.m_OwnsProvider && (this.m_Provider != 0))
            {
                SspiProvider.CryptReleaseContext(this.m_Provider, 0);
            }
            this.m_Handle = this.m_ExponentOfOne = this.m_Provider = 0;
            try
            {
                GC.SuppressFinalize(this);
            }
            catch
            {
            }
        }

        ~SymmetricKey()
        {
            this.Dispose();
        }

        private int GetPaddingMode(PaddingMode mode)
        {
            if (mode == PaddingMode.PKCS7)
            {
                return 1;
            }
            return 3;
        }

        private int KeyFromBytes(int provider, CryptoAlgorithm algorithm, byte[] key)
        {
            int dwFlags = 1;
            int dwProvSessionKeySize = 0;
            int dwPublicKeySize = 0;
            int offset = 0;
            int hTempKey = 0;
            int hSessionKey = 0;
            IntPtr algo = new IntPtr((int) algorithm);
            IntPtr dwPrivKeyAlg = IntPtr.Zero;
            IntPtr pbSessionBlob = IntPtr.Zero;
            IntPtr provEnum = IntPtr.Zero;
            try
            {
                int dwSize;
                int i;
                bool found = false;
                provEnum = Marshal.AllocHGlobal((int) (0x54 + IntPtr.Size));
                do
                {
                    dwSize = 0x54 + IntPtr.Size;
                    if (SspiProvider.CryptGetProvParam(provider, 0x16, provEnum, ref dwSize, dwFlags) == 0)
                    {
                        break;
                    }
                    dwFlags = 0;
                    if (Marshal.ReadIntPtr(provEnum) == algo)
                    {
                        found = true;
                    }
                }
                while (!found);
                if (!found)
                {
                    throw new SecurityException("CSP does not support selected algorithm.");
                }
                if (SspiProvider.CryptGenKey(provider, algo, 0, ref hTempKey) == 0)
                {
                    throw new SecurityException("Cannot generate temporary key.");
                }
                dwSize = 4;
                if (SspiProvider.CryptGetKeyParam(hTempKey, 9, ref dwProvSessionKeySize, ref dwSize, 0) == 0)
                {
                    throw new SecurityException("Cannot retrieve key parameters.");
                }
                if ((key.Length * 8) > dwProvSessionKeySize)
                {
                    throw new SecurityException("Key too big.");
                }
                dwSize = IntPtr.Size;
                if (SspiProvider.CryptGetKeyParam(this.m_ExponentOfOne, 7, ref dwPrivKeyAlg, ref dwSize, 0) == 0)
                {
                    throw new SecurityException("Unable to get the private key's algorithm.");
                }
                dwSize = 4;
                if (SspiProvider.CryptGetKeyParam(this.m_ExponentOfOne, 9, ref dwPublicKeySize, ref dwSize, 0) == 0)
                {
                    throw new SecurityException("Unable to get the key length.");
                }
                int dwSessionBlob = (((dwPublicKeySize / 8) + IntPtr.Size) + 4) + IntPtr.Size;
                pbSessionBlob = Marshal.AllocHGlobal(dwSessionBlob);
                PUBLICKEYSTRUC pks = new PUBLICKEYSTRUC {
                    bType = 1,
                    bVersion = 2,
                    reserved = 0,
                    aiKeyAlg = algo
                };
                Marshal.StructureToPtr(pks, pbSessionBlob, false);
                Marshal.WriteIntPtr(pbSessionBlob, offset = Marshal.SizeOf(pks), dwPrivKeyAlg);
                offset += IntPtr.Size;
                for (i = 0; i < key.Length; i++)
                {
                    Marshal.WriteByte(pbSessionBlob, ((offset + key.Length) - i) - 1, key[i]);
                }
                dwSize = dwSessionBlob - ((((IntPtr.Size + IntPtr.Size) + 4) + key.Length) + 3);
                offset += key.Length + 1;
                if (SspiProvider.CryptGenRandom(provider, dwSize, new IntPtr(pbSessionBlob.ToInt64() + offset)) == 0)
                {
                    throw new SecurityException("Could not generate random data.");
                }
                for (i = 0; i < dwSize; i++)
                {
                    if (Marshal.ReadByte(pbSessionBlob, offset) == 0)
                    {
                        Marshal.WriteByte(pbSessionBlob, offset, 1);
                    }
                    offset++;
                }
                Marshal.WriteByte(pbSessionBlob, dwSessionBlob - 2, 2);
                if (SspiProvider.CryptImportKey(provider, pbSessionBlob, dwSessionBlob, this.m_ExponentOfOne, 1, ref hSessionKey) == 0)
                {
                    throw new SecurityException("Cannot import key [key has right size?].");
                }
            }
            finally
            {
                if (provEnum != IntPtr.Zero)
                {
                    Marshal.FreeHGlobal(provEnum);
                }
                if (hTempKey != 0)
                {
                    SspiProvider.CryptDestroyKey(hTempKey);
                }
                if (pbSessionBlob != IntPtr.Zero)
                {
                    Marshal.FreeHGlobal(pbSessionBlob);
                }
            }
            return hSessionKey;
        }

        public byte[] ToBytes()
        {
            byte[] CS10000;
            if (this.m_Handle == 0)
            {
                throw new ObjectDisposedException(base.GetType().FullName);
            }
            IntPtr pbSessionBlob = IntPtr.Zero;
            try
            {
                int dwSessionBlob = 0;
                if (SspiProvider.CryptExportKey(this.m_Handle, this.m_ExponentOfOne, 1, 0, IntPtr.Zero, ref dwSessionBlob) == 0)
                {
                    throw new SecurityException("Cannot export key.");
                }
                pbSessionBlob = Marshal.AllocHGlobal(dwSessionBlob);
                if (SspiProvider.CryptExportKey(this.m_Handle, this.m_ExponentOfOne, 1, 0, pbSessionBlob, ref dwSessionBlob) == 0)
                {
                    throw new SecurityException("Cannot export key.");
                }
                int dwSize = 4;
                int dwKeyMaterial = 0;
                if (SspiProvider.CryptGetKeyParam(this.m_Handle, 9, ref dwKeyMaterial, ref dwSize, 0) == 0)
                {
                    throw new SecurityException("Cannot retrieve key parameters.");
                }
                dwKeyMaterial /= 8;
                byte[] pbKeyMaterial = new byte[dwKeyMaterial];
                int offset = 4 + IntPtr.Size;
                offset += IntPtr.Size;
                Marshal.Copy(new IntPtr(pbSessionBlob.ToInt64() + offset), pbKeyMaterial, 0, pbKeyMaterial.Length);
                Array.Reverse(pbKeyMaterial);
                CS10000 = pbKeyMaterial;
            }
            finally
            {
                if (pbSessionBlob != IntPtr.Zero)
                {
                    Marshal.FreeHGlobal(pbSessionBlob);
                }
            }
            return CS10000;
        }

        public override string ToString()
        {
            if (this.m_Handle == 0)
            {
                throw new ObjectDisposedException(base.GetType().FullName);
            }
            byte[] bytes = this.ToBytes();
            StringBuilder sb = new StringBuilder(bytes.Length * 2);
            for (int i = 0; i < bytes.Length; i++)
            {
                sb.Append(bytes[i].ToString("X2"));
            }
            return sb.ToString();
        }

        public int FeedbackSize
        {
            get
            {
                if (this.m_Handle == 0)
                {
                    throw new ObjectDisposedException(base.GetType().FullName);
                }
                int ret = 0;
                int length = 4;
                if (SspiProvider.CryptGetKeyParam(this.m_Handle, 5, ref ret, ref length, 0) == 0)
                {
                    throw new CryptographicException("Could not get the feedback size.");
                }
                return ret;
            }
            set
            {
                if (this.m_Handle == 0)
                {
                    throw new ObjectDisposedException(base.GetType().FullName);
                }
                if (SspiProvider.CryptSetKeyParam(this.m_Handle, 5, ref value, 0) == 0)
                {
                    throw new CryptographicException("Unable to set the feedback size.");
                }
            }
        }

        public int Handle
        {
            get
            {
                if (this.m_Handle == 0)
                {
                    throw new ObjectDisposedException(base.GetType().FullName);
                }
                return this.m_Handle;
            }
        }

        public byte[] IV
        {
            get
            {
                if (this.m_Handle == 0)
                {
                    throw new ObjectDisposedException(base.GetType().FullName);
                }
                int length = 0;
                if (SspiProvider.CryptGetKeyParam(this.m_Handle, 1, (byte[]) null, ref length, 0) == 0)
                {
                    throw new CryptographicException("Could not get the IV.");
                }
                byte[] buffer = new byte[length];
                if (SspiProvider.CryptGetKeyParam(this.m_Handle, 1, buffer, ref length, 0) == 0)
                {
                    throw new CryptographicException("Could not get the IV.");
                }
                return buffer;
            }
            set
            {
                if (this.m_Handle == 0)
                {
                    throw new ObjectDisposedException(base.GetType().FullName);
                }
                if (value == null)
                {
                    throw new ArgumentNullException();
                }
                if (SspiProvider.CryptSetKeyParam(this.m_Handle, 1, value, 0) == 0)
                {
                    throw new CryptographicException("Unable to set the initialization vector.");
                }
            }
        }

        public CipherMode Mode
        {
            get
            {
                if (this.m_Handle == 0)
                {
                    throw new ObjectDisposedException(base.GetType().FullName);
                }
                int ret = 0;
                int length = 4;
                if (SspiProvider.CryptGetKeyParam(this.m_Handle, 4, ref ret, ref length, 0) == 0)
                {
                    throw new CryptographicException("Could not get the cipher mode.");
                }
                return (CipherMode) ret;
            }
            set
            {
                if (this.m_Handle == 0)
                {
                    throw new ObjectDisposedException(base.GetType().FullName);
                }
                int mode = (int) value;
                if (SspiProvider.CryptSetKeyParam(this.m_Handle, 4, ref mode, 0) == 0)
                {
                    throw new CryptographicException("Unable to set the cipher mode.");
                }
            }
        }

        public PaddingMode Padding
        {
            get
            {
                return this.m_PaddingMode;
            }
            set
            {
                if (this.m_Handle == 0)
                {
                    throw new ObjectDisposedException(base.GetType().FullName);
                }
                int val = this.GetPaddingMode(value);
                if (SspiProvider.CryptSetKeyParam(this.m_Handle, 3, ref val, 0) == 0)
                {
                    throw new CryptographicException("Unable to set the padding type.");
                }
                this.m_PaddingMode = value;
            }
        }

        public int Provider
        {
            get
            {
                if (this.m_Handle == 0)
                {
                    throw new ObjectDisposedException(base.GetType().FullName);
                }
                return this.m_Provider;
            }
        }
    }
}