Files
JJBB/Assets/Plugins/Best HTTP/Source/SecureProtocol/crypto/prng/drbg/DrbgUtilities.cs
2024-08-23 15:49:34 +08:00

108 lines
3.3 KiB
C#

#if !BESTHTTP_DISABLE_ALTERNATE_SSL && (!UNITY_WEBGL || UNITY_EDITOR)
#pragma warning disable
using System;
using System.Collections;
using BestHTTP.SecureProtocol.Org.BouncyCastle.Utilities;
namespace BestHTTP.SecureProtocol.Org.BouncyCastle.Crypto.Prng.Drbg
{
internal class DrbgUtilities
{
private static readonly IDictionary maxSecurityStrengths = BestHTTP.SecureProtocol.Org.BouncyCastle.Utilities.Platform.CreateHashtable();
static DrbgUtilities()
{
maxSecurityStrengths.Add("SHA-1", 128);
maxSecurityStrengths.Add("SHA-224", 192);
maxSecurityStrengths.Add("SHA-256", 256);
maxSecurityStrengths.Add("SHA-384", 256);
maxSecurityStrengths.Add("SHA-512", 256);
maxSecurityStrengths.Add("SHA-512/224", 192);
maxSecurityStrengths.Add("SHA-512/256", 256);
}
internal static int GetMaxSecurityStrength(IDigest d)
{
return (int)maxSecurityStrengths[d.AlgorithmName];
}
internal static int GetMaxSecurityStrength(IMac m)
{
string name = m.AlgorithmName;
return (int)maxSecurityStrengths[name.Substring(0, name.IndexOf("/"))];
}
/**
* Used by both Dual EC and Hash.
*/
internal static byte[] HashDF(IDigest digest, byte[] seedMaterial, int seedLength)
{
// 1. temp = the Null string.
// 2. .
// 3. counter = an 8-bit binary value representing the integer "1".
// 4. For i = 1 to len do
// Comment : In step 4.1, no_of_bits_to_return
// is used as a 32-bit string.
// 4.1 temp = temp || Hash (counter || no_of_bits_to_return ||
// input_string).
// 4.2 counter = counter + 1.
// 5. requested_bits = Leftmost (no_of_bits_to_return) of temp.
// 6. Return SUCCESS and requested_bits.
byte[] temp = new byte[(seedLength + 7) / 8];
int len = temp.Length / digest.GetDigestSize();
int counter = 1;
byte[] dig = new byte[digest.GetDigestSize()];
for (int i = 0; i <= len; i++)
{
digest.Update((byte)counter);
digest.Update((byte)(seedLength >> 24));
digest.Update((byte)(seedLength >> 16));
digest.Update((byte)(seedLength >> 8));
digest.Update((byte)seedLength);
digest.BlockUpdate(seedMaterial, 0, seedMaterial.Length);
digest.DoFinal(dig, 0);
int bytesToCopy = ((temp.Length - i * dig.Length) > dig.Length)
? dig.Length
: (temp.Length - i * dig.Length);
Array.Copy(dig, 0, temp, i * dig.Length, bytesToCopy);
counter++;
}
// do a left shift to get rid of excess bits.
if (seedLength % 8 != 0)
{
int shift = 8 - (seedLength % 8);
uint carry = 0;
for (int i = 0; i != temp.Length; i++)
{
uint b = temp[i];
temp[i] = (byte)((b >> shift) | (carry << (8 - shift)));
carry = b;
}
}
return temp;
}
internal static bool IsTooLarge(byte[] bytes, int maxBytes)
{
return bytes != null && bytes.Length > maxBytes;
}
}
}
#pragma warning restore
#endif