apewer-dotnet/Apewer.Source/Externals/MySql.Data-6.10.9/MySqlClient/Crypt.cs

#if MYSQL_6_10

// Copyright ?2004, 2016 Oracle and/or its affiliates. All rights reserved.
//
// MySQL Connector/NET is licensed under the terms of the GPLv2
// <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>, like most 
// MySQL Connectors. There are special exceptions to the terms and 
// conditions of the GPLv2 as it is applied to this software, see the 
// FLOSS License Exception
// <http://www.mysql.com/about/legal/licensing/foss-exception.html>.
//
// This program is free software; you can redistribute it and/or modify 
// it under the terms of the GNU General Public License as published 
// by the Free Software Foundation; version 2 of the License.
//
// This program is distributed in the hope that it will be useful, but 
// WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 
// for more details.
//
// You should have received a copy of the GNU General Public License along 
// with this program; if not, write to the Free Software Foundation, Inc., 
// 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA

using System;
using System.Security.Cryptography;

#if NETSTANDARD1_3
using Externals.MySql.Data.MySqlClient.Framework.NetStandard1_3;
#else
using System.Text;
#endif

namespace Externals.MySql.Data.MySqlClient
{
    /// <summary>
    /// Summary description for Crypt.
    /// </summary>
    internal class Crypt
    {
        /// <summary>
        /// Simple XOR scramble
        /// </summary>
        /// <param name="from">Source array</param>
        /// <param name="fromIndex">Index inside source array</param>
        /// <param name="to">Destination array</param>
        /// <param name="toIndex">Index inside destination array</param>
        /// <param name="password">Password used to xor the bits</param>
        /// <param name="length">Number of bytes to scramble</param>
        private static void XorScramble(byte[] from, int fromIndex, byte[] to, int toIndex,
                        byte[] password, int length)
        {
            // make sure we were called properly
            if (fromIndex < 0 || fromIndex >= from.Length)
                throw new ArgumentException(Resources.IndexMustBeValid, nameof(fromIndex));
            if ((fromIndex + length) > from.Length)
                throw new ArgumentException(Resources.FromAndLengthTooBig, nameof(fromIndex));
            if (from == null)
                throw new ArgumentException(Resources.BufferCannotBeNull, nameof(@from));
            if (to == null)
                throw new ArgumentException(Resources.BufferCannotBeNull, nameof(to));
            if (toIndex < 0 || toIndex >= to.Length)
                throw new ArgumentException(Resources.IndexMustBeValid, nameof(toIndex));
            if ((toIndex + length) > to.Length)
                throw new ArgumentException(Resources.IndexAndLengthTooBig, nameof(toIndex));
            if (password == null || password.Length < length)
                throw new ArgumentException(Resources.PasswordMustHaveLegalChars, nameof(password));
            if (length < 0)
                throw new ArgumentException(Resources.ParameterCannotBeNegative, nameof(length));

            // now perform the work
            for (int i = 0; i < length; i++)
                to[toIndex++] = (byte)(from[fromIndex++] ^ password[i]);
        }

        /// <summary>
        /// Returns a byte array containing the proper encryption of the 
        /// given password/seed according to the new 4.1.1 authentication scheme.
        /// </summary>
        /// <param name="password"></param>
        /// <param name="seed"></param>
        /// <returns></returns>
        public static byte[] Get411Password(string password, string seed)
        {
            // if we have no password, then we just return 2 zero bytes
            if (password.Length == 0) return new byte[1];

            SHA1 sha = SHA1.Create();

            byte[] firstHash = sha.ComputeHash(Encoding.Default.GetBytes(password));
            byte[] secondHash = sha.ComputeHash(firstHash);
            byte[] seedBytes = Encoding.Default.GetBytes(seed);

            byte[] input = new byte[seedBytes.Length + secondHash.Length];
            Array.Copy(seedBytes, 0, input, 0, seedBytes.Length);
            Array.Copy(secondHash, 0, input, seedBytes.Length, secondHash.Length);
            byte[] thirdHash = sha.ComputeHash(input);

            byte[] finalHash = new byte[thirdHash.Length + 1];
            finalHash[0] = 0x14;
            Array.Copy(thirdHash, 0, finalHash, 1, thirdHash.Length);

            for (int i = 1; i < finalHash.Length; i++)
                finalHash[i] = (byte)(finalHash[i] ^ firstHash[i - 1]);
            return finalHash;
            //byte[] buffer = new byte[finalHash.Length - 1];
            //Array.Copy(finalHash, 1, buffer, 0, finalHash.Length - 1);
            //return buffer;
        }

        private static double rand(ref long seed1, ref long seed2, long max)
        {
            seed1 = (seed1 * 3) + seed2;
            seed1 %= max;
            seed2 = (seed1 + seed2 + 33) % max;
            return (seed1 / (double)max);
        }

        /// <summary>
        /// Encrypts a password using the MySql encryption scheme
        /// </summary>
        /// <param name="password">The password to encrypt</param>
        /// <param name="seed">The encryption seed the server gave us</param>
        /// <param name="new_ver">Indicates if we should use the old or new encryption scheme</param>
        /// <returns></returns>
        public static String EncryptPassword(String password, String seed, bool new_ver)
        {
            long max = 0x3fffffff;
            if (!new_ver)
                max = 0x01FFFFFF;
            if (string.IsNullOrEmpty(password))
                return password;

            long[] hash_seed = Hash(seed);
            long[] hash_pass = Hash(password);

            long seed1 = (hash_seed[0] ^ hash_pass[0]) % max;
            long seed2 = (hash_seed[1] ^ hash_pass[1]) % max;
            if (!new_ver)
                seed2 = seed1 / 2;

            char[] scrambled = new char[seed.Length];
            for (int x = 0; x < seed.Length; x++)
            {
                double r = rand(ref seed1, ref seed2, max);
                scrambled[x] = (char)(Math.Floor(r * 31) + 64);
            }

            if (new_ver)
            {
                /* Make it harder to break */
                char extra = (char)Math.Floor(rand(ref seed1, ref seed2, max) * 31);
                for (int x = 0; x < scrambled.Length; x++)
                    scrambled[x] ^= extra;
            }

            return new string(scrambled);
        }

        /// <summary>
        /// Hashes a password using the algorithm from Monty's code.
        /// The first element in the return is the result of the "old" hash.
        /// The second element is the rest of the "new" hash.
        /// </summary>
        /// <param name="P">Password to be hashed</param>
        /// <returns>Two element array containing the hashed values</returns>
        private static long[] Hash(String P)
        {
            long val1 = 1345345333;
            long val2 = 0x12345671;
            long inc = 7;

            for (int i = 0; i < P.Length; i++)
            {
                if (P[i] == ' ' || P[i] == '\t') continue;
                long temp = (0xff & P[i]);
                val1 ^= (((val1 & 63) + inc) * temp) + (val1 << 8);
                val2 += (val2 << 8) ^ val1;
                inc += temp;
            }

            long[] hash = new long[2];
            hash[0] = val1 & 0x7fffffff;
            hash[1] = val2 & 0x7fffffff;
            return hash;
        }
    }
}

#endif