Cryptography

Overview

MvcCore Utilidades provides cryptography utilities through the HelperCryptography static class, which offers two approaches to content encryption:

Basic Encryption: Simple SHA1-based hashing
Efficient Encryption: Advanced SHA512-based hashing with salt and multiple iterations

The CifradosController demonstrates practical implementation of these cryptography features.

Key Components

HelperCryptography

Static helper class providing encryption and hashing methods. Namespace: MvcCoreUtilidades.Helpers Key Features:

SHA1-based basic encryption
SHA512-based efficient encryption with salt
Automatic salt generation
Multiple iteration hashing for enhanced security

CifradosController

Controller demonstrating encryption usage for both basic and efficient methods. Namespace: MvcCoreUtilidades.Controllers

HelperCryptography Methods

EncriptarTextoBasico

Provides basic SHA1 hashing for content.

contenido

string

required

The content to encrypt

Returns: string - The encrypted content using SHA1

public static string EncriptarTextoBasico(string contenido)

Implementation:

public static string EncriptarTextoBasico(string contenido)
{
    byte[] entrada;
    byte[] salida;
    UnicodeEncoding encoding = new UnicodeEncoding();
    SHA1 managed = SHA1.Create();
    entrada = encoding.GetBytes(contenido);
    salida = managed.ComputeHash(entrada);

    string resultado = encoding.GetString(salida);
    return resultado;
}

SHA1 is considered cryptographically weak for password storage. Use CifrarContenido for production applications.

CifrarContenido

Provides advanced SHA512 hashing with salt and multiple iterations.

contenido

string

required

The content to encrypt

comparar

bool

required

false: Generate new salt (for initial encryption)
true: Use existing salt (for comparison/verification)

Returns: string - The encrypted content using SHA512 with salt

public static string CifrarContenido(string contenido, bool comparar)

Implementation:

public static string CifrarContenido(string contenido, bool comparar)
{
    if (comparar == false)
    {
        Salt = GenerateSalt();
    }

    string contenidoSalt = contenido + Salt;
    SHA512 managed = SHA512.Create();
    UnicodeEncoding encoding = new UnicodeEncoding();
    byte[] salida;
    salida = encoding.GetBytes(contenidoSalt);
    
    // Apply 12 iterations for enhanced security
    for (int i = 1; i <= 12; i++)
    {
        salida = managed.ComputeHash(salida);
    }
    
    managed.Clear();
    string resultado = encoding.GetString(salida);
    return resultado;
}

Salt Property

Static property that stores the generated salt value.

public static string Salt { get; set; }

The salt must be stored and reused when comparing encrypted values. Store it securely (e.g., in a database) alongside the encrypted content.

GenerateSalt (Private)

Generates a random 30-character salt string.

private static string GenerateSalt()
{
    Random random = new Random();
    string salt = "";
    for (int i = 1; i <= 30; i++)
    {
        int num = random.Next(1, 255);
        char letra = Convert.ToChar(num);
        salt += letra;
    }
    return salt;
}

Controller Implementation

CifradoBasico Actions

GET Action
POST Action

public IActionResult CifradoBasico()
{
    return View();
}

[HttpPost]
public IActionResult CifradoBasico(string contenido, string resultado, string accion)
{
    string response = HelperCryptography.EncriptarTextoBasico(contenido);
    
    if (accion.ToLower() == "cifrar")
    {
        ViewData["TEXTOCIFRADO"] = response;
    }
    else if (accion.ToLower() == "comparar")
    {
        if (response != resultado)
        {
            ViewData["MENSAJE"] = "Los datos no coinciden";
        }
        else
        {
            ViewData["MENSAJE"] = "Contenidos iguales!!!";
        }
    }
    return View();
}

CifradoEficiente Actions

GET Action
POST Action

public IActionResult CifradoEficiente()
{
    return View();
}

[HttpPost]
public IActionResult CifradoEficiente(string contenido, string resultado, string accion)
{
    if (accion.ToLower() == "cifrar")
    {
        // Generate new salt for encryption
        string response = HelperCryptography.CifrarContenido(contenido, false);
        ViewData["TEXTOCIFRADO"] = response;
        ViewData["SALT"] = HelperCryptography.Salt;
    }
    else if (accion.ToLower() == "comparar")
    {
        // Use existing salt for comparison
        string response = HelperCryptography.CifrarContenido(contenido, true);
        if (response != resultado)
        {
            ViewData["MENSAJE"] = "Los datos son distintos...";
        }
        else
        {
            ViewData["MENSAJE"] = "Los datos son IGUALES!!!";
        }
    }
    return View();
}

Usage Examples

Basic Encryption

using MvcCoreUtilidades.Helpers;

// Encrypt password
string password = "mySecurePassword123";
string encrypted = HelperCryptography.EncriptarTextoBasico(password);

// Compare passwords
string userInput = "mySecurePassword123";
string encryptedInput = HelperCryptography.EncriptarTextoBasico(userInput);

if (encrypted == encryptedInput)
{
    Console.WriteLine("Password is correct");
}
else
{
    Console.WriteLine("Password is incorrect");
}

Efficient Encryption (Recommended)

Encrypt and store

// First time encryption - generate new salt
string password = "mySecurePassword123";
string encrypted = HelperCryptography.CifrarContenido(password, false);
string salt = HelperCryptography.Salt;

// Store both 'encrypted' and 'salt' in database
// Example:
// user.PasswordHash = encrypted;
// user.PasswordSalt = salt;

Verify on login

// Retrieve stored salt from database
string storedSalt = user.PasswordSalt;
string storedHash = user.PasswordHash;

// Set the salt before comparison
HelperCryptography.Salt = storedSalt;

// Encrypt user input with existing salt
string userInput = "mySecurePassword123";
string encryptedInput = HelperCryptography.CifrarContenido(userInput, true);

if (encryptedInput == storedHash)
{
    Console.WriteLine("Login successful");
}
else
{
    Console.WriteLine("Invalid credentials");
}

public class AuthenticationService
{
    // Registration
    public User RegisterUser(string username, string password)
    {
        // Encrypt password with new salt
        string encryptedPassword = HelperCryptography.CifrarContenido(password, false);
        string salt = HelperCryptography.Salt;
        
        var user = new User
        {
            Username = username,
            PasswordHash = encryptedPassword,
            PasswordSalt = salt,
            CreatedDate = DateTime.Now
        };
        
        // Save to database
        _context.Users.Add(user);
        _context.SaveChanges();
        
        return user;
    }
    
    // Login verification
    public bool ValidateLogin(string username, string password)
    {
        var user = _context.Users.FirstOrDefault(u => u.Username == username);
        
        if (user == null)
            return false;
        
        // Set the stored salt
        HelperCryptography.Salt = user.PasswordSalt;
        
        // Encrypt input with existing salt
        string encryptedInput = HelperCryptography.CifrarContenido(password, true);
        
        // Compare hashes
        return encryptedInput == user.PasswordHash;
    }
}

Comparison: Basic vs Efficient

Feature	Basic Encryption	Efficient Encryption
Algorithm	SHA1	SHA512
Salt	No	Yes (30 chars)
Iterations	1	12
Security	Low (deprecated)	High
Use Case	Testing only	Production
Speed	Faster	Slower (more secure)

Security Considerations

Never use Basic Encryption for passwords: SHA1 is cryptographically broken and should not be used for password storage in production applications.

Salt Storage: Always store the salt value alongside the encrypted content. Without the original salt, you cannot verify the content later.

Best Practices

Use Efficient Encryption for all password storage
Store salt securely in your database alongside the hash
Never log or display encrypted passwords or salts
Use HTTPS when transmitting passwords
Consider modern alternatives like ASP.NET Core Identity or BCrypt for new projects

Modern Alternative

For new projects, consider using ASP.NET Core Identity’s built-in password hasher:

using Microsoft.AspNetCore.Identity;

public class ModernPasswordService
{
    private readonly IPasswordHasher<User> _passwordHasher;
    
    public ModernPasswordService()
    {
        _passwordHasher = new PasswordHasher<User>();
    }
    
    public string HashPassword(User user, string password)
    {
        return _passwordHasher.HashPassword(user, password);
    }
    
    public bool VerifyPassword(User user, string hashedPassword, string providedPassword)
    {
        var result = _passwordHasher.VerifyHashedPassword(user, hashedPassword, providedPassword);
        return result == PasswordVerificationResult.Success;
    }
}

Common Pitfalls

Forgetting to Set Salt for Comparison

// WRONG - Salt not set
string encrypted = HelperCryptography.CifrarContenido(userInput, true);
// This will use the last generated salt, which may be incorrect

// CORRECT - Salt explicitly set
HelperCryptography.Salt = storedSalt;
string encrypted = HelperCryptography.CifrarContenido(userInput, true);

Using Basic Encryption for Production

// WRONG - Insecure for production
string hash = HelperCryptography.EncriptarTextoBasico(password);

// CORRECT - Use efficient encryption
string hash = HelperCryptography.CifrarContenido(password, false);
string salt = HelperCryptography.Salt;

Source Reference

HelperCryptography: Helpers/HelperCryptography.cs:6
CifradosController: Controllers/CifradosController.cs:6
CifrarContenido method: Helpers/HelperCryptography.cs:24
EncriptarTextoBasico method: Helpers/HelperCryptography.cs:45

Getting Started

Core Utilities

Examples

Overview

Key Components

HelperCryptography

CifradosController

HelperCryptography Methods

EncriptarTextoBasico

CifrarContenido

Salt Property

GenerateSalt (Private)

Controller Implementation

CifradoBasico Actions

CifradoEficiente Actions

Usage Examples

Basic Encryption

Efficient Encryption (Recommended)

Comparison: Basic vs Efficient

Security Considerations

Best Practices

Modern Alternative

Common Pitfalls

Forgetting to Set Salt for Comparison

Using Basic Encryption for Production

Source Reference

Build docs developers (and LLMs) love

Getting Started

Core Utilities

Examples

​Overview

​Key Components

​HelperCryptography

​CifradosController

​HelperCryptography Methods

​EncriptarTextoBasico

​CifrarContenido

​Salt Property

​GenerateSalt (Private)

​Controller Implementation

​CifradoBasico Actions

​CifradoEficiente Actions

​Usage Examples

​Basic Encryption

​Efficient Encryption (Recommended)

​Complete Example: User Registration and Login

​Comparison: Basic vs Efficient

​Security Considerations

​Best Practices

​Modern Alternative

​Common Pitfalls

​Forgetting to Set Salt for Comparison

​Using Basic Encryption for Production

​Source Reference

Build docs developers (and LLMs) love

Overview

Key Components

HelperCryptography

CifradosController

HelperCryptography Methods

EncriptarTextoBasico

CifrarContenido

Salt Property

GenerateSalt (Private)

Controller Implementation

CifradoBasico Actions

CifradoEficiente Actions

Usage Examples

Basic Encryption

Efficient Encryption (Recommended)

Complete Example: User Registration and Login

Comparison: Basic vs Efficient

Security Considerations

Best Practices

Modern Alternative

Common Pitfalls

Forgetting to Set Salt for Comparison

Using Basic Encryption for Production

Source Reference