The = is padding. <!————> Wikipedia says An additional pad character is allocated which may be used to force the encoded output into an integer multiple of 4 characters (or equivalently when the unencoded binary text is not a multiple of 3 bytes) ; these padding characters must then be discarded when decoding but still … Read more
If you want a stream that converts to Base64, you can put a ToBase64Transform into a CryptoStream: new CryptoStream(stream, new ToBase64Transform(), CryptoStreamMode.Write) If you just want to convert a single byte array to Base64, you can simply call Convert.ToBase64String(bytes). In both cases, you can replace the word To with From.
You can use the following regular expression to check if a string constitutes a valid base64 encoding: ^([A-Za-z0-9+/]{4})*([A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{2}==)?$ In base64 encoding, the character set is [A-Z, a-z, 0-9, and + /]. If the rest length is less than 4, the string is padded with ‘=’ characters. ^([A-Za-z0-9+/]{4})* means the string starts with 0 or more … Read more
Base64 encodes each set of three bytes into four bytes. In addition the output is padded to always be a multiple of four. This means that the size of the base-64 representation of a string of size n is: ceil(n / 3) * 4 So, for a 16kB array, the base-64 representation will be ceil(16*1024/3)*4 … Read more
Base64 isn’t an encryption. It’s a coding. There is no key in Base64. There are lots of ways to get base64 decoded (a random search shows this as one of them). Your problem seems to be that the data, in addition to being coded, is also encrypted. Unless you know what it is encrypted with, … Read more