将现有用户从 MVC 4 SimpleMembership 迁移到 MVC 5 ASP.NET Identity

根据 http://www.asp.net/identity/overview/migrations/migrating-an-existing-website-from-sql-membership-to-aspnet-identity

应用程序用户的密码被加密并存储在数据库中。SQL 成员身份中使用的加密算法与新标识系统中的加密算法不同。要重用旧密码，我们需要在老用户使用 SQL 成员资格算法登录时有选择地解密密码，同时在新用户的 Identity 中使用加密算法。

UserManager 类有一个属性"PasswordHasher"，它存储实现"IPasswordHasher"接口的类的实例。这用于在用户身份验证事务期间加密/解密密码。在步骤 3 中定义的 UserManager 类中，创建一个新类 SQLPasswordHasher 并复制以下代码。

因此，您必须使用以下代码创建新的哈希器类：

public class SQLPasswordHasher : PasswordHasher
  {
    public override string HashPassword(string password)
    {
        return base.HashPassword(password);
    }
public override PasswordVerificationResult VerifyHashedPassword(string  hashedPassword, string providedPassword)
    {
        string[] passwordProperties = hashedPassword.Split('|');
        if (passwordProperties.Length != 3)
        {
            return base.VerifyHashedPassword(hashedPassword, providedPassword);
        }
        else
        {
            string passwordHash = passwordProperties[0];
            int passwordformat = 1;
            string salt = passwordProperties[2];
            if (String.Equals(EncryptPassword(providedPassword, passwordformat, salt), passwordHash, StringComparison.CurrentCultureIgnoreCase))
            {
                return PasswordVerificationResult.SuccessRehashNeeded;
            }
            else
            {
                return PasswordVerificationResult.Failed;
            }
        }
    }
//This is copied from the existing SQL providers and is provided only for back-compat.
    private string EncryptPassword(string pass, int passwordFormat, string salt)
    {
        if (passwordFormat == 0) // MembershipPasswordFormat.Clear
            return pass;
        byte[] bIn = Encoding.Unicode.GetBytes(pass);
        byte[] bSalt = Convert.FromBase64String(salt);
        byte[] bRet = null;
        if (passwordFormat == 1)
        { // MembershipPasswordFormat.Hashed 
            HashAlgorithm hm = HashAlgorithm.Create("SHA1");
            if (hm is KeyedHashAlgorithm)
            {
                KeyedHashAlgorithm kha = (KeyedHashAlgorithm)hm;
                if (kha.Key.Length == bSalt.Length)
                {
                    kha.Key = bSalt;
                }
                else if (kha.Key.Length < bSalt.Length)
                {
                    byte[] bKey = new byte[kha.Key.Length];
                    Buffer.BlockCopy(bSalt, 0, bKey, 0, bKey.Length);
                    kha.Key = bKey;
                }
                else
                {
                    byte[] bKey = new byte[kha.Key.Length];
                    for (int iter = 0; iter < bKey.Length; )
                    {
                        int len = Math.Min(bSalt.Length, bKey.Length - iter);
                        Buffer.BlockCopy(bSalt, 0, bKey, iter, len);
                        iter += len;
                    }
                    kha.Key = bKey;
                }
                bRet = kha.ComputeHash(bIn);
            }
            else
            {
                byte[] bAll = new byte[bSalt.Length + bIn.Length];
                Buffer.BlockCopy(bSalt, 0, bAll, 0, bSalt.Length);
                Buffer.BlockCopy(bIn, 0, bAll, bSalt.Length, bIn.Length);
                bRet = hm.ComputeHash(bAll);
            }
        }
        return Convert.ToBase64String(bRet);
    }

然后在您的 Identity UserManager 类中声明一个构造器以使用此哈希器，例如：

public UserManager()
        : base(new UserStore<User>(new ApplicationDbContext()))
    {
        this.PasswordHasher = new SQLPasswordHasher();
}

在以下链接中说明：http://kevin-junghans.blogspot.com/2014/02/migrating-existing-website-from.html

  public class SimplePasswordHasher : IPasswordHasher
  {
     public string HashPassword(string password)
     {
        return Crypto.HashPassword(password);
     }
     public PasswordVerificationResult VerifyHashedPassword(string hashedPassword, string providedPassword)
     {
        if(Crypto.VerifyHashedPassword(hashedPassword, providedPassword))
        return PasswordVerificationResult.Success;
        else return PasswordVerificationResult.Failed;
      }  
  }