Improve avatar validation.

2 files changed, 60 insertions, 17 deletions

diff --git a/Timeline/Controllers/UserAvatarController.cs b/Timeline/Controllers/UserAvatarController.cs
index 6dc767df..710ca764 100644
--- a/Timeline/Controllers/UserAvatarController.cs
+++ b/Timeline/Controllers/UserAvatarController.cs
@@ -19,9 +19,28 @@ namespace Timeline.Controllers
 

             public const int Put_UserNotExist = -2001;

             public const int Put_Forbid = -2002;

+            public const int Put_BadFormat_CantDecode = -2011;

+            public const int Put_BadFormat_UnmatchedFormat = -2012;

+            public const int Put_BadFormat_BadSize = -2013;

 

             public const int Delete_UserNotExist = -3001;

             public const int Delete_Forbid = -3002;

+

+

+            public static int From(AvatarDataException.ErrorReason error)

+            {

+                switch (error)

+                {

+                    case AvatarDataException.ErrorReason.CantDecode:

+                        return Put_BadFormat_CantDecode;

+                    case AvatarDataException.ErrorReason.UnmatchedFormat:

+                        return Put_BadFormat_UnmatchedFormat;

+                    case AvatarDataException.ErrorReason.BadSize:

+                        return Put_BadFormat_BadSize;

+                    default:

+                        throw new Exception("Unknown AvatarDataException.ErrorReason value.");

+                }

+            }

         }

 

         private readonly ILogger<UserAvatarController> _logger;

@@ -43,9 +62,9 @@ namespace Timeline.Controllers
                 var avatar = await _service.GetAvatar(username);

                 return File(avatar.Data, avatar.Type);

             }

-            catch (UserNotExistException)

+            catch (UserNotExistException e)

             {

-                _logger.LogInformation($"Attempt to get a avatar of a non-existent user failed. Username: {username} .");

+                _logger.LogInformation(e, $"Attempt to get a avatar of a non-existent user failed. Username: {username} .");

                 return NotFound(new CommonResponse(ErrorCodes.Get_UserNotExist, "User does not exist."));

             }

         }

@@ -76,11 +95,16 @@ namespace Timeline.Controllers
                 _logger.LogInformation($"Succeed to put a avatar of a user. Username: {username} ; Mime Type: {Request.ContentType} .");

                 return Ok();

             }

-            catch (UserNotExistException)

+            catch (UserNotExistException e)

             {

-                _logger.LogInformation($"Attempt to put a avatar of a non-existent user failed. Username: {username} .");

+                _logger.LogInformation(e, $"Attempt to put a avatar of a non-existent user failed. Username: {username} .");

                 return BadRequest(new CommonResponse(ErrorCodes.Put_UserNotExist, "User does not exist."));

             }

+            catch (AvatarDataException e)

+            {

+                _logger.LogInformation(e, $"Attempt to put a avatar of a bad format failed. Username: {username} .");

+                return BadRequest(new CommonResponse(ErrorCodes.From(e.Error), "Bad format."));

+            }

         }

 

         [HttpDelete("users/{username}/avatar")]

@@ -101,9 +125,9 @@ namespace Timeline.Controllers
                 _logger.LogInformation($"Succeed to delete a avatar of a user. Username: {username} .");

                 return Ok();

             }

-            catch (UserNotExistException)

+            catch (UserNotExistException e)

             {

-                _logger.LogInformation($"Attempt to delete a avatar of a non-existent user failed. Username: {username} .");

+                _logger.LogInformation(e, $"Attempt to delete a avatar of a non-existent user failed. Username: {username} .");

                 return BadRequest(new CommonResponse(ErrorCodes.Delete_UserNotExist, "User does not exist."));

             }

         }

diff --git a/Timeline/Services/UserAvatarService.cs b/Timeline/Services/UserAvatarService.cs
index 2a73cde5..dd0e5e7c 100644
--- a/Timeline/Services/UserAvatarService.cs
+++ b/Timeline/Services/UserAvatarService.cs
@@ -24,12 +24,29 @@ namespace Timeline.Services
     [Serializable]

     public class AvatarDataException : Exception

     {

-        public AvatarDataException(Avatar avatar, string message) : base(message) { Avatar = avatar; }

-        public AvatarDataException(Avatar avatar, string message, Exception inner) : base(message, inner) { Avatar = avatar; }

+        public enum ErrorReason

+        {

+            /// <summary>

+            /// Decoding image failed.

+            /// </summary>

+            CantDecode,

+            /// <summary>

+            /// Decoding succeeded but the real type is not the specified type.

+            /// </summary>

+            UnmatchedFormat,

+            /// <summary>

+            /// Image is not a square.

+            /// </summary>

+            BadSize

+        }

+

+        public AvatarDataException(Avatar avatar, ErrorReason error, string message) : base(message) { Avatar = avatar; Error = error; }

+        public AvatarDataException(Avatar avatar, ErrorReason error, string message, Exception inner) : base(message, inner) { Avatar = avatar; Error = error; }

         protected AvatarDataException(

           System.Runtime.Serialization.SerializationInfo info,

           System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

 

+        public ErrorReason Error { get; set; }

         public Avatar Avatar { get; set; }

     }

 

@@ -49,7 +66,12 @@ namespace Timeline.Services
 

     public interface IUserAvatarValidator

     {

-        Task<(bool valid, string message)> Validate(Avatar avatar);

+        /// <summary>

+        /// Validate a avatar's format and size info.

+        /// </summary>

+        /// <param name="avatar">The avatar to validate.</param>

+        /// <exception cref="AvatarDataException">Thrown when validation failed.</exception>

+        Task Validate(Avatar avatar);

     }

 

     public interface IUserAvatarService

@@ -96,7 +118,7 @@ namespace Timeline.Services
 

     public class UserAvatarValidator : IUserAvatarValidator

     {

-        public Task<(bool valid, string message)> Validate(Avatar avatar)

+        public Task Validate(Avatar avatar)

         {

             return Task.Run(() =>

             {

@@ -105,15 +127,14 @@ namespace Timeline.Services
                     using (var image = Image.Load(avatar.Data, out IImageFormat format))

                     {

                         if (!format.MimeTypes.Contains(avatar.Type))

-                            return (false, "Image's actual mime type is not the specified one.");

+                            throw new AvatarDataException(avatar, AvatarDataException.ErrorReason.UnmatchedFormat, "Image's actual mime type is not the specified one.");

                         if (image.Width != image.Height)

-                            return (false, "Image is not a square, aka width is not equal to height.");

+                            throw new AvatarDataException(avatar, AvatarDataException.ErrorReason.BadSize, "Image is not a square, aka, width is not equal to height.");

                     }

-                    return (true, "A good avatar.");

                 }

                 catch (UnknownImageFormatException e)

                 {

-                    return (false, $"Failed to decode image. Exception: {e} .");

+                  throw new AvatarDataException(avatar, AvatarDataException.ErrorReason.CantDecode, "Failed to decode image. See inner exception.", e);

                 }

             });

         }

@@ -196,9 +217,7 @@ namespace Timeline.Services
             }

             else

             {

-                (bool valid, string message) = await _avatarValidator.Validate(avatar);

-                if (!valid)

-                    throw new AvatarDataException(avatar, $"Failed to validate image. {message}");

+                await _avatarValidator.Validate(avatar);

 

                 if (avatarEntity == null)

                 {