internal static byte GenerateRandomNumber(this FreeformSecurityTable secTable)
{
using (ILogMethod method = Log.LogMethod(DYN_MODULE_NAME, "GenerateRandomNumber"))
{
byte result = 0;
try
{
int count = 10;
while (count-- > 0)
{
byte[] lohi = secTable.GenerateRandomNumberLowHigh();
secTable.PartialKeyIndex = (byte)(secTable.PartialKeyIndex > 0 ? secTable.PartialKeyIndex - 1 : 8);
result = (byte)(lohi[0] ^ lohi[1]);// ^ secTable.OtherPartialKey[secTable.PartialKeyIndex]);
if (result > 0)
{
break;
}
}
}
catch (Exception ex)
{
method.Exception(ex);
return(0);
}
return(result);
}
}
internal static bool StoreOtherPartialKeyHost(this FreeformSecurityTableCollection secTables, SECURITY_KEY_INDEX key, byte[] partialKey)
{
using (ILogMethod method = Log.LogMethod(DYN_MODULE_NAME, "StoreOtherPartialKey"))
{
try
{
if (!secTables.ContainsKey(key))
{
return(false);
}
FreeformSecurityTable secTable = secTables[key];
int length = FreeformSecurityTable.KEY_SIZE_2;
for (int i = 0; i < length; ++i)
{
secTable.OtherPartialKey[i] = (byte)(partialKey[i] ^ ((byte)(0x50 + i)));
}
// method
secTable.Method = (((partialKey[length - 1] ^ 0xA5) >> 2) & 0x0F);
// indicates that other key is generated and common key is unusable
secTable.Flags = (secTable.Flags | FreeformSecurityFlags.OtherPartialKey) & ~FreeformSecurityFlags.CommonKey;
}
catch (Exception ex)
{
method.Exception(ex);
return(false);
}
return(true);
}
}
internal static bool StoreOtherPartialKeyGmu(this FreeformSecurityTableCollection secTables, SECURITY_KEY_INDEX key, byte[] partialKey)
{
using (ILogMethod method = Log.LogMethod(DYN_MODULE_NAME, "StoreOtherPartialKey"))
{
try
{
if (!secTables.ContainsKey(key))
{
return(false);
}
FreeformSecurityTable secTable = secTables[key];
int length = FreeformSecurityTable.KEY_SIZE;
for (int i = 0, j = length - 1; i < length; i++, j = ((j + 3) & 0x7))
{
secTable.OtherPartialKey[j] = partialKey[i];
}
// indicates that other key is generated and common key is unusable
secTable.Flags = (secTable.Flags | FreeformSecurityFlags.OtherPartialKey) & ~FreeformSecurityFlags.CommonKey;
}
catch (Exception ex)
{
method.Exception(ex);
return(false);
}
return(true);
}
}
internal static byte[] CreatePartialKeyHost(this FreeformSecurityTableCollection secTables, SECURITY_KEY_INDEX key)
{
using (ILogMethod method = Log.LogMethod(DYN_MODULE_NAME, "CreatePartialKey"))
{
byte[] result = null;
try
{
if (!secTables.ContainsKey(key))
{
return(result);
}
FreeformSecurityTable secTable = secTables[key];
byte[] keys = alphan;
int j = 0;
if (secTable.Method > (FK_1ST - 1))
{
secTable.Method = ((0xC3 * 100) % (FK_LST - FK_1ST + 1)) + FK_1ST;
}
if (secTable.Method == (int)FreeformSecurityMethodTypes.Alpha1)
{
keys = alpha1;
}
else if (secTable.Method == (int)FreeformSecurityMethodTypes.Alpha2)
{
keys = alpha2;
}
else
{
j = secTable.Method;
}
int i = 0;
for (int k = 3; i < 8; ++i, k = (k + 3) & 7)
{
secTable.LocalPartialKey[k] = exp_mod(keys[i + j], secTable.LocalRandomNumber[i]);
}
secTable.LocalPartialKey[8] = (byte)((0xC3 | (secTable.Method << 2)) ^ 0xA5);
// indicates that local partial key is generated and common key is unusable
secTable.Flags = (secTable.Flags | FreeformSecurityFlags.LocalPartialKey) & ~FreeformSecurityFlags.CommonKey;
result = secTable.LocalPartialKey;
}
catch (Exception ex)
{
method.Exception(ex);
return(null);
}
return(result);
}
}
internal static bool DecryptHost(this FreeformSecurityTableCollection secTables, SECURITY_KEY_INDEX key, ref byte[] data)
{
using (ILogMethod method = Log.LogMethod(DYN_MODULE_NAME, "Decrypt"))
{
if (data == null || data.Length == 0)
{
return(false);
}
try
{
if (!secTables.ContainsKey(key))
{
return(false);
}
FreeformSecurityTable secTable = secTables[key];
if ((secTable.Flags & FreeformSecurityFlags.CommonKey) != FreeformSecurityFlags.CommonKey)
{
return(false);
}
int j = 0;
if (secTable.Method == (int)FreeformSecurityMethodTypes.Alpha2)
{
j = 5;
}
for (int i = 0; i < data.Length; ++i)
{
data[i] ^= (byte)(secTable.CommonKey[(i + j) & 0x7] ^ fudge1[i & 0xF]);
}
}
catch (Exception ex)
{
method.Exception(ex);
return(false);
}
return(true);
}
}
internal static bool CreateCommonKey(this FreeformSecurityTableCollection secTables, SECURITY_KEY_INDEX key)
{
using (ILogMethod method = Log.LogMethod(DYN_MODULE_NAME, "CreateCommonKey"))
{
try
{
if (!secTables.ContainsKey(key))
{
return(false);
}
FreeformSecurityTable secTable = secTables[key];
if (secTable.Flags != (FreeformSecurityFlags.LocalPartialKey |
FreeformSecurityFlags.OtherPartialKey))
{
return(false);
}
byte[] localNum = secTable.LocalRandomNumber;
for (int i = 0; i < FreeformSecurityTable.KEY_SIZE; i++)
{
secTable.CommonKey[i] = exp_mod(secTable.OtherPartialKey[i], localNum[i]);
}
// all the keys are now available
secTable.Flags |= (FreeformSecurityFlags.LocalPartialKey |
FreeformSecurityFlags.OtherPartialKey |
FreeformSecurityFlags.CommonKey);
}
catch (Exception ex)
{
method.Exception(ex);
return(false);
}
return(true);
}
}
internal static bool ClearKeyData(this FreeformSecurityTableCollection secTables, SECURITY_KEY_INDEX key)
{
using (ILogMethod method = Log.LogMethod(DYN_MODULE_NAME, "Decrypt"))
{
try
{
if (!secTables.ContainsKey(key))
{
return(false);
}
FreeformSecurityTable secTable = secTables[key];
// clear the flags
secTable.Flags = 0;
// clear common key
for (int i = 0; i < secTable.CommonKey.Length; i++)
{
secTable.CommonKey[i] = 0;
}
// clear local key
for (int i = 0; i < secTable.LocalRandomNumber.Length; i++)
{
secTable.LocalRandomNumber[i] = 0;
}
}
catch (Exception ex)
{
method.Exception(ex);
return(false);
}
return(true);
}
}
internal static byte[] CreatePartialKeyGmu(this FreeformSecurityTableCollection secTables, SECURITY_KEY_INDEX key)
{
using (ILogMethod method = Log.LogMethod(DYN_MODULE_NAME, "CreatePartialKey"))
{
byte[] result = null;
try
{
if (!secTables.ContainsKey(key))
{
return(result);
}
FreeformSecurityTable secTable = secTables[key];
byte[] keys = alphan;
int j = 0;
// initial method
if (secTable.Method == (int)FreeformSecurityMethodTypes.None)
{
secTable.Method = (int)FreeformSecurityMethodTypes.Alpha1;
}
if (secTable.Method == (int)FreeformSecurityMethodTypes.Alpha1)
{
keys = alpha1;
}
else if (secTable.Method == (int)FreeformSecurityMethodTypes.Alpha2)
{
keys = alpha2;
}
else
{
j = secTable.Method;
}
// 0 - 7
for (int i = 0; i < FreeformSecurityTable.KEY_SIZE; i++)
{
secTable.LocalPartialKey[i] = Convert.ToByte((exp_mod(keys[i + j], secTable.LocalRandomNumber[i]))
^ Convert.ToByte(0x50 + i));
}
// 8
j = FreeformSecurityTable.KEY_SIZE;
secTable.LocalPartialKey[j] = Convert.ToByte(((secTable.LocalRandomNumber[j] & 0xC3) |
(secTable.Method << 2)) ^ 0xA5);
// indicates that local partial key is generated and common key is unusable
secTable.Flags = (secTable.Flags | FreeformSecurityFlags.LocalPartialKey) & ~FreeformSecurityFlags.CommonKey;
result = secTable.LocalPartialKey;
}
catch (Exception ex)
{
method.Exception(ex);
return(null);
}
return(result);
}
}
