C#: Hash암호화(MD5, SHA256, SHA384, SHA512) 및 비교와 AES256 암/복호화 DLL

매번 코드를 추가하는게 귀찮아서 dll파일로 만들어서 Github에 올려둔다.

Github : github.com/vip00112/Cryptor

 

[전체 코드]

1. Hash (MD5, SHA256/384/512)

using System;
using System.Text;

namespace Cryptor
{
    public class Hash
    {
        public enum HashType { MD5, SHA256, SHA384, SHA512 }

        /// <summary>
        /// MD5 암호화
        /// </summary>
        /// <param name="text">암호화 할 평문</param>
        /// <param name="encoding">System.Text.Encoding</param>
        /// <returns>지정된 인코딩으로 암호화한 문자열</returns>
        public static string EncryptMD5(string text, Encoding encoding)
        {
            var md5 = System.Security.Cryptography.MD5.Create();
            byte[] data = md5.ComputeHash(encoding.GetBytes(text));

            var sb = new StringBuilder();
            foreach (byte b in data)
            {
                sb.Append(b.ToString("x2"));
            }
            return sb.ToString();
        }

        /// <summary>
        /// SHA256 암호화
        /// </summary>
        /// <param name="text">암호화 할 평문</param>
        /// <param name="encoding">System.Text.Encoding</param>
        /// <returns>지정된 인코딩으로 암호화한 문자열</returns>
        public static string EncryptSHA256(string text, Encoding encoding)
        {
            var sha = new System.Security.Cryptography.SHA256Managed();
            byte[] data = sha.ComputeHash(encoding.GetBytes(text));

            var sb = new StringBuilder();
            foreach (byte b in data)
            {
                sb.Append(b.ToString("x2"));
            }
            return sb.ToString();
        }

        /// <summary>
        /// SHA384 암호화
        /// </summary>
        /// <param name="text">암호화 할 평문</param>
        /// <param name="encoding">System.Text.Encoding</param>
        /// <returns>지정된 인코딩으로 암호화한 문자열</returns>
        public static string EncryptSHA384(string text, Encoding encoding)
        {
            var sha = new System.Security.Cryptography.SHA384Managed();
            byte[] data = sha.ComputeHash(encoding.GetBytes(text));

            var sb = new StringBuilder();
            foreach (byte b in data)
            {
                sb.Append(b.ToString("x2"));
            }
            return sb.ToString();
        }

        /// <summary>
        /// SHA512 암호화
        /// </summary>
        /// <param name="text">암호화 할 평문</param>
        /// <param name="encoding">System.Text.Encoding</param>
        /// <returns>지정된 인코딩으로 암호화한 문자열</returns>
        public static string EncryptSHA512(string text, Encoding encoding)
        {
            var sha = new System.Security.Cryptography.SHA512Managed();
            byte[] data = sha.ComputeHash(encoding.GetBytes(text));

            var sb = new StringBuilder();
            foreach (byte b in data)
            {
                sb.Append(b.ToString("x2"));
            }
            return sb.ToString();
        }

        /// <summary>
        /// 평문화 Hash 암호화 문자열 비교
        /// </summary>
        /// <param name="text">평문</param>
        /// <param name="oldHash">Hash 암호화 문자열</param>
        /// <param name="type">MD5, SHA256, SHA384, SHA512</param>
        /// <param name="encoding">System.Text.Encoding</param>
        /// <returns>평문을 지정된 인코딩으로 암호화한 후 비교 결과 True/False</returns>
        public static bool IsSameHash(string text, string oldHash, HashType type, Encoding encoding)
        {
            string newHash = null;
            switch (type)
            {
                case HashType.MD5:
                    newHash = EncryptMD5(text, encoding);
                    break;
                case HashType.SHA256:
                    newHash = EncryptSHA256(text, encoding);
                    break;
                case HashType.SHA384:
                    newHash = EncryptSHA384(text, encoding);
                    break;
                case HashType.SHA512:
                    newHash = EncryptSHA512(text, encoding);
                    break;
                default:
                    return false;
            }
            var comparer = StringComparer.OrdinalIgnoreCase;
            return comparer.Compare(newHash, oldHash) == 0;
        }
    }
}

 

2. AES

using System;
using System.Security.Cryptography;
using System.Text;
using System.IO;

namespace Cryptor
{
    public class AES
    {
        /// <summary>
        /// AES256 암호화
        /// </summary>
        /// <param name="text">평문</param>
        /// <param name="key">암호화할 키 값</param>
        /// <param name="encoding">System.Text.Encoding</param>
        /// <returns>지정된 인코딩으로 암호화한 문자열</returns>
        public static string Encrypt(string text, string key, Encoding encoding)
        {
            try
            {
                byte[] textData = encoding.GetBytes(text);
                byte[] salt = Encoding.ASCII.GetBytes(key.Length.ToString());
                var secretKey = new PasswordDeriveBytes(key, salt);

                var aes = new RijndaelManaged();
                ICryptoTransform encryptor = aes.CreateEncryptor(secretKey.GetBytes(32), secretKey.GetBytes(16));

                using (var ms = new MemoryStream())
                using (var cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write))
                {
                    cs.Write(textData, 0, textData.Length);
                    cs.FlushFinalBlock();
                    return Convert.ToBase64String(ms.ToArray());
                }
            }
            catch (Exception e)
            {
                return "Encrypt error : " + e.Message;
            }
        }

        /// <summary>
        /// AES256 복호화
        /// </summary>
        /// <param name="encryptText">암호화된 문자열</param>
        /// <param name="key">복호화할 키 값</param>
        /// <param name="encoding">System.Text.Encoding</param>
        /// <returns>지정된 인코딩으로 복호화한 문자열</returns>
        public static string Decrypt(string encryptText, string key, Encoding encoding)
        {
            try
            {
                byte[] encryptData = Convert.FromBase64String(encryptText);
                byte[] salt = Encoding.ASCII.GetBytes(key.Length.ToString());
                var secretKey = new PasswordDeriveBytes(key, salt);

                var aes = new RijndaelManaged();
                ICryptoTransform decryptor = aes.CreateDecryptor(secretKey.GetBytes(32), secretKey.GetBytes(16));

                using (var ms = new MemoryStream())
                using (var cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Write))
                {
                    byte[] result = new byte[encryptData.Length];
                    int decryptedCount = cs.Read(result, 0, result.Length);
                    return encoding.GetString(result, 0, decryptedCount);
                }
            }
            catch (Exception e)
            {
                return "Decrypt error : " + e.Message;
            }
        }
    }
}

 

 

[사용 방법]

1. Hash 암호화 및 비교

            // MD5
            string text = "Plan text for hash test.";
            string hash = Hash.EncryptMD5(text, Encoding.Unicode);
            bool isSame = Hash.IsSameHash(text, hash, Hash.HashType.MD5, Encoding.Unicode);
            Console.WriteLine(isSame); // Output : true

            // SHA256
            string text = "Plan text for hash test.";
            string hash = Hash.EncryptSHA256(text, Encoding.Unicode);
            bool isSame = Hash.IsSameHash(text, hash, Hash.HashType.SHA256, Encoding.Unicode);
            Console.WriteLine(isSame); // Output : true

            // SHA256
            string text = "Plan text for hash test.";
            string hash = Hash.EncryptSHA384(text, Encoding.Unicode);
            bool isSame = Hash.IsSameHash(text, hash, Hash.HashType.SHA384, Encoding.Unicode);
            Console.WriteLine(isSame); // Output : true

            // SHA256
            string text = "Plan text for hash test.";
            string hash = Hash.EncryptSHA512(text, Encoding.Unicode);
            bool isSame = Hash.IsSameHash(text, hash, Hash.HashType.SHA512, Encoding.Unicode);
            Console.WriteLine(isSame); // Output : true

 

2. AES 암/복호화

            // AES
            string text = "Plan text for aes test.";
            string key = "Key for aes test.";
            string encrypted = AES.Encrypt(text, key, Encoding.Unicode);
            Console.WriteLine(encrypted);

            string decrypted = AES.Decrypt(encrypted, key, Encoding.Unicode);
            Console.WriteLine(decrypted);

            bool isSame = text == decrypted;
            Console.WriteLine(isSame); // Output : true