Encryption Key Chars

[co-dax]

Is it safe to use the whole range of UTF-8 characters that are part of the byte in UTF-8 encoding?
I am referring to code points from U+0000 to U+007F at the following page https://en.wikipedia.org/wiki/UTF-8#Encoding and the characters related to that range (from U+0000 to U+007F) are at the following page https://www.utf8-chartable.de/.
I am asking this since I noticed not all the characters are used when generating keys with EncryptProvider.CreateAesKey(). The range being used in the source code is:
char[] arrChar = new char[]{ 'a','b','d','c','e','f','g','h','i','j','k','l','m','n','p','r','q','s','t','u','v','w','z','y','x', '0','1','2','3','4','5','6','7','8','9', 'A','B','C','D','E','F','G','H','I','J','K','L','M','N','Q','P','R','T','S','V','U','W','X','Y','Z' };

I tried using some UTF-8 codes outside of the range from code above but still in the range from U+0000 to U+007F and it worked fine.

Is it safe to use that kind of chars for encryption key?

From the following excerpt from the source code I can see that you are using Encoding.UTF8.GetBytes(...) to decode UTF chars to byte array so I guess it should be safe to use any of UTF-8 chars from the range U+0000 to U+007F for encryption key:

`public static byte[] AESDecrypt(byte[] data, string key, string vector)
{
Check.Argument.IsNotEmpty(data, nameof(data));

        Check.Argument.IsNotEmpty(key, nameof(key));
        Check.Argument.IsEqualLength(key.Length, 32, nameof(key));

        Check.Argument.IsNotEmpty(vector, nameof(vector));
        Check.Argument.IsEqualLength(vector.Length, 16, nameof(vector));

        byte[] encryptedBytes = data;
        byte[] bKey = new byte[32];
        Array.Copy(Encoding.UTF8.GetBytes(key.PadRight(bKey.Length)), bKey, bKey.Length);
        byte[] bVector = new byte[16];
        Array.Copy(Encoding.UTF8.GetBytes(vector.PadRight(bVector.Length)), bVector, bVector.Length);

        byte[] decryptedData = null; // decrypted data

        using (Aes Aes = Aes.Create())
        {
            try
            {
                using (MemoryStream memory = new MemoryStream(encryptedBytes))
                {
                    using (CryptoStream decryptor = new CryptoStream(memory, Aes.CreateDecryptor(bKey, bVector), CryptoStreamMode.Read))
                    {
                        using (MemoryStream tempMemory = new MemoryStream())
                        {
                            byte[] Buffer = new byte[1024];
                            Int32 readBytes = 0;
                            while ((readBytes = decryptor.Read(Buffer, 0, Buffer.Length)) > 0)
                            {
                                tempMemory.Write(Buffer, 0, readBytes);
                            }

                            decryptedData = tempMemory.ToArray();
                        }
                    }
                }
            }
            catch
            {
                decryptedData = null;
            }

            return decryptedData;
        }
    }`

Thanks!

[myloveCc]

EncryptProvider.CreateAesKey() method only provides a convenient way to create a key, as long as the key meets the requirements, it can be used as a key.