Add features to easy validate types in web projects

Author: AJMitev

FileTypeChecker.Web/Attributes/AllowedTypesAttribute.cs

@@ -0,0 +1,43 @@
+namespace FileTypeChecker.Web.Attributes
+{
+    using FileTypeChecker.Web.Infrastructure;
+    using Microsoft.AspNetCore.Http;
+    using System;
+    using System.ComponentModel.DataAnnotations;
+    using System.IO;
+    using System.Linq;
+
+    [AttributeUsage(AttributeTargets.Property)]
+    public class AllowedTypesAttribute : ValidationAttribute
+    {
+        private readonly string[] extensions;
+
+        public AllowedTypesAttribute(params string[] extensions)
+            => this.extensions = extensions;
+
+        protected override ValidationResult IsValid(object value, ValidationContext validationContext)
+        {
+            if (!(value is IFormFile file))
+            {
+                return ValidationResult.Success;
+            }
+
+            using var stream = new MemoryStream();
+            file.CopyTo(stream);
+
+            if (!FileTypeValidator.IsTypeRecognizable(stream))
+            {
+                return new ValidationResult(Constants.ErrorMessages.UnsupportedFileErrorMessage);
+            }
+
+            var fileType = FileTypeValidator.GetFileType(stream);
+
+            if (!extensions.Contains(fileType.Extension.ToLower()))
+            {
+                return new ValidationResult(Constants.ErrorMessages.InvalidFileTypeErrorMessage);
+            }
+
+            return ValidationResult.Success;
+        }
+    }
+}

FileTypeChecker.Web/Attributes/ForbidExecutableFileAttribute.cs

@@ -0,0 +1,37 @@
+namespace FileTypeChecker.Web.Attributes
+{
+    using FileTypeChecker.Extensions;
+    using FileTypeChecker.Types;
+    using FileTypeChecker.Web.Infrastructure;
+    using Microsoft.AspNetCore.Http;
+    using System;
+    using System.ComponentModel.DataAnnotations;
+    using System.IO;
+
+    [AttributeUsage(AttributeTargets.Property)]
+    public class ForbidExecutableFileAttribute : ValidationAttribute
+    {
+        protected override ValidationResult IsValid(object value, ValidationContext validationContext)
+        {
+            if (!(value is IFormFile file))
+            {
+                return ValidationResult.Success;
+            }
+
+            using var stream = new MemoryStream();
+            file.CopyTo(stream);
+
+            if (!FileTypeValidator.IsTypeRecognizable(stream))
+            {
+                return new ValidationResult(Constants.ErrorMessages.UnsupportedFileErrorMessage);
+            }
+
+            if (stream.Is<Executable>() || stream.Is<ExecutableAndLinkableFormat>())
+            {
+                return new ValidationResult(Constants.ErrorMessages.InvalidFileTypeErrorMessage);
+            }
+
+            return ValidationResult.Success;
+        }
+    }
+}

FileTypeChecker.Web/Attributes/ForbidTypesAttribute.cs

@@ -0,0 +1,44 @@
+namespace FileTypeChecker.Web.Attributes
+{
+    using FileTypeChecker.Web.Infrastructure;
+    using Microsoft.AspNetCore.Http;
+    using System;
+    using System.ComponentModel.DataAnnotations;
+    using System.IO;
+    using System.Linq;
+
+
+    [AttributeUsage(AttributeTargets.Property)]
+    public class ForbidTypesAttribute : ValidationAttribute
+    {
+        private readonly string[] extensions;
+
+        public ForbidTypesAttribute(params string[] extensions)
+            => this.extensions = extensions;
+
+        protected override ValidationResult IsValid(object value, ValidationContext validationContext)
+        {
+            if (!(value is IFormFile file))
+            {
+                return ValidationResult.Success;
+            }
+
+            using var stream = new MemoryStream();
+            file.CopyTo(stream);
+
+            if (!FileTypeValidator.IsTypeRecognizable(stream))
+            {
+                return new ValidationResult(Constants.ErrorMessages.UnsupportedFileErrorMessage);
+            }
+
+            var fileType = FileTypeValidator.GetFileType(stream);
+
+            if (extensions.Contains(fileType.Extension.ToLower()))
+            {
+                return new ValidationResult(Constants.ErrorMessages.InvalidFileTypeErrorMessage);
+            }
+
+            return ValidationResult.Success;
+        }
+    }
+}

FileTypeChecker.Web/Attributes/OnlyArchiveAttribute.cs

@@ -0,0 +1,36 @@
+namespace FileTypeChecker.Web.Attributes
+{
+    using FileTypeChecker.Extensions;
+    using FileTypeChecker.Web.Infrastructure;
+    using Microsoft.AspNetCore.Http;
+    using System;
+    using System.ComponentModel.DataAnnotations;
+    using System.IO;
+
+    [AttributeUsage(AttributeTargets.Property)]
+    public class OnlyArchiveAttribute : ValidationAttribute
+    {
+        protected override ValidationResult IsValid(object value, ValidationContext validationContext)
+        {
+            if (!(value is IFormFile file))
+            {
+                return ValidationResult.Success;
+            }
+
+            using var stream = new MemoryStream();
+            file.CopyTo(stream);
+
+            if (!FileTypeValidator.IsTypeRecognizable(stream))
+            {
+                return new ValidationResult(Constants.ErrorMessages.UnsupportedFileErrorMessage);
+            }
+
+            if (!stream.IsArchive())
+            {
+                return new ValidationResult(Constants.ErrorMessages.InvalidFileTypeErrorMessage);
+            }
+
+            return ValidationResult.Success;
+        }
+    }
+}

FileTypeChecker.Web/Attributes/OnlyImageAttribute.cs

@@ -0,0 +1,36 @@
+namespace FileTypeChecker.Web.Attributes
+{
+    using FileTypeChecker.Extensions;
+    using FileTypeChecker.Web.Infrastructure;
+    using Microsoft.AspNetCore.Http;
+    using System;
+    using System.ComponentModel.DataAnnotations;
+    using System.IO;
+
+    [AttributeUsage(AttributeTargets.Property)]
+    public class OnlyImageAttribute : ValidationAttribute
+    {
+        protected override ValidationResult IsValid(object value, ValidationContext validationContext)
+        {
+            if (!(value is IFormFile file))
+            {
+                return ValidationResult.Success;
+            }
+
+            using var stream = new MemoryStream();
+            file.CopyTo(stream);
+
+            if (!FileTypeValidator.IsTypeRecognizable(stream))
+            {
+                return new ValidationResult(Constants.ErrorMessages.UnsupportedFileErrorMessage);
+            }
+
+            if (!stream.IsImage())
+            {
+                return new ValidationResult(Constants.ErrorMessages.InvalidFileTypeErrorMessage);
+            }
+
+            return ValidationResult.Success;
+        }
+    }
+}

FileTypeChecker.Web/FileTypeChecker.Web.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netstandard2.0</TargetFramework>
+    <LangVersion>8.0</LangVersion>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="File.TypeChecker" Version="1.3.0" />
+    <PackageReference Include="Microsoft.AspNetCore.Http.Features" Version="3.1.3" />
+    <PackageReference Include="System.ComponentModel.Annotations" Version="4.7.0" />
+  </ItemGroup>
+
+</Project>

FileTypeChecker.Web/Infrastructure/Constants.cs

@@ -0,0 +1,11 @@
+namespace FileTypeChecker.Web.Infrastructure
+{
+    internal static class Constants
+    {
+        internal static class ErrorMessages
+        {
+            public const string UnsupportedFileErrorMessage = "Provided file is not of supported type. Please provide a valid file!";
+            public const string InvalidFileTypeErrorMessage = "This type of file is not allowed!";
+        }
+    }
+}