Problem with EF Encryption When You Set *Length Attributes -> Documentation

When you set *Length (i.e. MaxLength and StringLength) attributes the model creator will honour that length as NVARCHAR(X) instead of the original NVARCHAR(MAX).

This is ordinarily optimal except when encrypting more space is used as a result of the encryption process. So a 'hacky' workaround is below.

        /// <summary>
        /// Overrides Model Creation System, We want all fields labelled with [Encrypted] to be encrypted
        /// </summary>
        /// <param name="modelBuilder"></param>
        protected override void OnModelCreating(ModelBuilder modelBuilder)
                {
            base.OnModelCreating(modelBuilder);

            modelBuilder.UseEncryption(_provider);

            //Adjust each field that is encrypted to be NVARCHAR(MAX) as opposed to NVARCHAR(50) or whatever
            //We have to allow for encrypted size
            foreach (var property in modelBuilder.Model.GetEntityTypes().SelectMany(t => t.GetProperties()).Where(p => p.ClrType == typeof(string)))
            {
                var memberInfo = property.PropertyInfo ?? (MemberInfo)property.FieldInfo;
                var encryptedAttribute = memberInfo?.GetCustomAttribute<EncryptedAttribute>();
                if (encryptedAttribute == null) continue;
                //Ok so we have an [Encrypted] attribute
                //Convert to nvarchar(max), to ensure all data is not truncated
                property.SetColumnType("NVARCHAR(MAX)");
            }
        }

Now there's some consensus on not mixing View Models with Data Models, which I do understand, but simple app, simple solution, why define twice. Both the server side and client side have the same rules, i.e. max lengths, have a certain format etc etc.

Enables:

        [Encrypted]
        [MinLength(4, ErrorMessage = "Your email address must have at least 4 characters")]
        [MaxLength(75, ErrorMessage = "Your email address cannot exceed 75 characters")]
        [Required(ErrorMessage = "Your email address is required")]
        [DataType(DataType.EmailAddress, ErrorMessage = "Your email address does not conform to a standard email address")]
        public string EmailAddress { get; set; }

Eastrall / EntityFrameworkCore.DataEncryption

Problem with EF Encryption When You Set *Length Attributes -> Documentation #6