Пример высокоуровневого протокола безопасного исполнения SQL-запросов к СУБД

csusing System;using System.Collections.Generic;using System. Linq;using System. Text;using System.Security.Cryptography;using System. IO;namespace SecureSQLClient{publicclassNVEncoder {List<byte> data;public NVEncoder () { data = newList<byte>(); }publicvoid Add (string name, byte[] data) {if (string.IsNullOrEmpty (name)) return;if (data == null — data. Length == 0) return;byte[] nameData = Encoding. UTF8.GetBytes (name);byte[] nameLength = BitConverter. GetBytes (nameData.Length);this.data.AddRange (nameLength);this.data.AddRange (nameData);byte[] dataLenght = BitConverter. GetBytes (data.Length);this.data.AddRange (dataLenght);this.data.AddRange (data); }publicbyte[] ToPackage () {return data. ToArray (); } }publicclassNVDecoder {privatebyte[] data;privateint pos;public NVDecoder (byte[] data) {this.data = data;this.pos = 0; }publicbyte[] ReadData (string name) {if (data == null) returnnull;int pos_save = pos;int cycle = 0;while (cycle == 0 — pos < pos_save) {if ((pos + 4) >= data. Length) { pos = 0;returnnull; }int len = BitConverter. ToInt32(data, pos); pos += 4;if ((pos + len) >= data. Length) { pos = 0;returnnull; }string item_name = Encoding. UTF8.GetString (data, pos, len);bool cmpresult = name == item_name; pos += len;if ((pos + 4) >= data. Length) { pos = 0;returnnull; } len = BitConverter. ToInt32(data, pos); pos += 4;if ((pos + len) > data. Length) { pos = 0;returnnull; }if (cmpresult) pos_save = pos; pos += len;if (pos >= data. Length) { cycle = 1; pos = 0; }if (cmpresult) {byte[] result = newbyte[len]; Array. Copy (data, pos_save, result, 0, len);return result; } }returnnull; } }publicstructSymParams {publicbyte[] key;publicbyte[] iv; }publicstaticclassRSANVExport {publicstaticbyte[] ExportPublicKey (RSAParameters rsa) {NVEncoder encoder = newNVEncoder (); encoder. Add («e», rsa. Exponent); encoder. Add («m», rsa. Modulus);return encoder. ToPackage (); }publicstaticstring ExportPublicKeyBase64(RSAParameters rsa) {returnConvert.ToBase64String (ExportPublicKey (rsa)); }publicstaticbyte[] ExportAllKey (RSAParameters rsa) {NVEncoder encoder = newNVEncoder (); encoder. Add («d», rsa. D); encoder. Add («dp», rsa. DP); encoder. Add («dq», rsa. DQ); encoder. Add («e», rsa. Exponent); encoder. Add («iq», rsa. InverseQ); encoder. Add («m», rsa. Modulus); encoder. Add («p», rsa. P); encoder. Add («q», rsa. Q);return encoder. ToPackage (); }publicstaticstring ExportAllKeyBase64(RSAParameters rsa) {returnConvert.ToBase64String (ExportAllKey (rsa)); } }publicstaticclassRSANVImport {publicstaticRSAParameters ImportPublicKey (byte[] data) {RSAParameters res = newRSAParameters ();NVDecoder decoder = newNVDecoder (data); res. Exponent = decoder. ReadData («e»); res. Modulus = decoder. ReadData («m»);return res; }publicstaticRSAParameters ImportPublicKeyBase64(string data) {return ImportPublicKey (Convert.FromBase64String (data)); }publicstaticRSAParameters ImportAllKey (byte[] data) {RSAParameters res = newRSAParameters ();NVDecoder decoder = newNVDecoder (data); res. D = decoder. ReadData («d»); res. DP = decoder. ReadData («dp»); res. DQ = decoder. ReadData («dq»); res. Exponent = decoder. ReadData («e»); res. Modulus = decoder. ReadData («m»); res. InverseQ = decoder. ReadData («iq»); res. P = decoder. ReadData («p»); res. Q = decoder. ReadData («q»);return res; }publicstaticRSAParameters ImportAllKeyBase64(string data) {return ImportAllKey (Convert.FromBase64String (data)); } }publicclassRSAWrapper {publicstaticRSAParameters GenerateKeyPair (int length) {using (var rsa = newRSACryptoServiceProvider (length)) {return rsa. ExportParameters (true); } }publicstaticbyte[] EncryptAssym (byte[] message, RSAParameters rsa) {using (var provider = newRSACryptoServiceProvider ()) { provider. ImportParameters (rsa);return provider. Encrypt (message, true); } }publicstaticbyte[] DecryptAssym (byte[] message, RSAParameters rsa) {using (var provider = newRSACryptoServiceProvider ()) { provider. ImportParameters (rsa);return provider. Decrypt (message, true); } }publicstaticSymParams GenerateSymParams () {SymParams result = newSymParams ();using (RijndaelManaged myRijndael = newRijndaelManaged ()) { myRijndael. GenerateKey (); myRijndael. GenerateIV (); result. key = myRijndael.Key.ToArray (); result. iv = myRijndael.IV.ToArray (); }return result; }publicstaticbyte[] EncryptSym (byte[] data, SymParams symParams) {byte[] encrypted = null;using (RijndaelManaged rijAlg = newRijndaelManaged ()) { rijAlg. Key = symParams.key.ToArray (); rijAlg. IV = symParams.iv.ToArray ();ICryptoTransform encryptor = rijAlg. CreateEncryptor (rijAlg.Key, rijAlg. IV);using (MemoryStream msEncrypt = newMemoryStream ()) {using (CryptoStream csEncrypt = newCryptoStream (msEncrypt, encryptor, CryptoStreamMode. Write)) { csEncrypt. Write (data, 0, data. Length); csEncrypt. Close (); } encrypted = msEncrypt. ToArray ();} }return encrypted; }publicstaticbyte[] DecryptSym (byte[] cipherText, SymParams sp) {byte[] result = null;using (RijndaelManaged rijAlg = newRijndaelManaged ()) { rijAlg. Key = sp. key; rijAlg. IV = sp. iv;ICryptoTransform decryptor = rijAlg. CreateDecryptor (rijAlg.Key, rijAlg. IV);using (MemoryStream msDecrypt = newMemoryStream ()) {using (CryptoStream csDecrypt = newCryptoStream (msDecrypt, decryptor, CryptoStreamMode. Write)) { csDecrypt. Write (cipherText, 0, cipherText. Length); csDecrypt. Close (); } result = msDecrypt. ToArray ();} }return result; } }}Keys.csusing System;using System.Collections.Generic;using System. Linq;using System. Text;namespace SecureSQLClient{publicstaticclassKeys {publicstaticstring publicKey = @" AQAAAGUDAAAAAQABAQAAAG2AAAAAz4KSl7GvS/x67Q5p1PmpxReiNQ7viaJipWrcRjlkektPnVrfaeBmdRn9oHSJ7EekIw/9/UJ4QoRjIh+mNw7dSqWuI0awv88D22sd1XYhzjrsPa7DBcjuRd1tGJcH5cM0mF1w16YuFab+GGspwY8ipGd0t1+9/SigH+vJK+fJHOs=";}}Program.csusing System;using System.Collections.Generic;using System. Linq;using System. Text;using System. IO;using System. Reflection;namespace SecureSQLClient{classProgram {staticvoid Main (string[] args) {string fileSend = Assembly. GetExecutingAssembly ().Location + «.send.dat» ;string fileRecv = Assembly. GetExecutingAssembly ().Location + «.recv.dat» ;string fileRecvTxt = Assembly. GetExecutingAssembly ().Location + «.recv.txt» ;ContractClient proxy = newContractClient ();try {var publicKey = RSANVImport. ImportPublicKeyBase64(Keys.publicKey);var privateKey = RSAWrapper. GenerateKeyPair (1024);var publicKeyForServer = RSANVExport. ExportPublicKeyBase64(privateKey);var firstPartSymKey = RSAWrapper. GenerateSymParams ();// отправка половины ключа и получение полного ключа в режиме асинхронного шифрованияvar c = proxy.ChannelFactory.CreateChannel ();List<byte> send = newList<byte>(); send. AddRange (RSAWrapper.EncryptAssym (firstPartSymKey.key, publicKey)); send. AddRange (UTF8Encoding.UTF8.GetBytes (publicKeyForServer));var p = c. GetSyncKey (send.ToArray ());byte[] pd = RSAWrapper. DecryptAssym (p, privateKey);// формирование ключа для шифрования запросовSymParams sp = newSymParams ();sp.iv = newbyte[16]; sp. key = newbyte[32]; Array. Copy (pd, 0, sp. iv, 0, 16);Array.Copy (pd, 16, sp. key, 0, 32);while (true) {Console.WriteLine («Enter SQL Query or 'QUIT' for exit: „);string query = Console. ReadLine (); //“ SELECT * FROM Employees» ;if (query == «QUIT» — query == «quit») break;byte[] qsend = RSAWrapper. EncryptSym (UTF8Encoding.UTF8.GetBytes (query), sp);File.WriteAllBytes (fileSend, qsend);Console.WriteLine («SQL Query encrypted in file send.dat. Change file or continue…»);Console.ReadLine (); qsend = File. ReadAllBytes (fileSend);byte[] qrecv = c. SQLQuery (qsend);File.WriteAllBytes (fileRecv, qrecv);Console.WriteLine («SQL Query answer received in file recv.dat. Change file or continue…»);Console.ReadLine (); qrecv = File. ReadAllBytes (fileRecv);byte[] dec = RSAWrapper. DecryptSym (qrecv, sp);string answer = UTF8Encoding. UTF8.GetString (dec);File.WriteAllText (fileRecvTxt, answer);Console.WriteLine (answer);Console.WriteLine (); } }catch (Exception e) {Console.WriteLine (e.Message); }Console.WriteLine («Длязавершениянажмите <ENTER>.nn»);Console.ReadLine (); proxy. Close (); } }}.