private const string _secret = "xxx";
        public static string CreateTokenForIdentity(Login identity)
        {
            byte[] key = Convert.FromBase64String(_secret);
            SymmetricSecurityKey securityKey = new SymmetricSecurityKey(key);
            SecurityTokenDescriptor descriptor = new SecurityTokenDescriptor
            {
                Subject = new ClaimsIdentity(new[] {
                      new Claim(ClaimTypes.Email, identity.mail),
                      new Claim(ClaimTypes.Role, identity.admin.ToString())
                }),
                Expires = DateTime.UtcNow.AddMinutes(120),
                SigningCredentials = new SigningCredentials(securityKey,
                SecurityAlgorithms.HmacSha256Signature)
            };

            JwtSecurityTokenHandler handler = new JwtSecurityTokenHandler();
            JwtSecurityToken token = handler.CreateJwtSecurityToken(descriptor);

            return handler.WriteToken(token);
        }

        public static IPrincipal getIdentity(string token)
        {
            
                JwtSecurityTokenHandler tokenHandler = new JwtSecurityTokenHandler();
                JwtSecurityToken jwtToken = (JwtSecurityToken)tokenHandler.ReadToken(token);
                if (jwtToken == null)
                    return null;
                byte[] key = Convert.FromBase64String(_secret);
                TokenValidationParameters parameters = new TokenValidationParameters()
                {
                    RequireExpirationTime = true,
                    ValidateIssuer = false,
                    ValidateAudience = false,
                    ValidateIssuerSigningKey = false,
                    IssuerSigningKey = new SymmetricSecurityKey(key)
                };

                SecurityToken securityToken;
                ClaimsPrincipal principal = tokenHandler.ValidateToken(token, parameters, out securityToken);

                Thread.CurrentPrincipal = principal;

                return principal;
           
        }

    "Message": "An error has occurred.",
    "ExceptionMessage": "IDX10503: Signature validation failed. Keys tried: 'System.Text.StringBuilder'.\nExceptions caught:\n 'System.Text.StringBuilder'.\ntoken: 'System.IdentityModel.Tokens.Jwt.JwtSecurityToken'.",
    "ExceptionType": "Microsoft.IdentityModel.Tokens.SecurityTokenInvalidSignatureException"