![]() ![]() The existing Convert.ToBase64String method in the System namespace takes a byte as a parameter and returns a string. NET comes with a respectable Base64 converter. It’s slow, unoptimized and pretty useless considering. What we’re writing here is for educational purposes. Writing your own encoderįirst, a disclaimer. Our final string, padded with = for the two missing octets, is RGF2ZQ=. That leaves us with 011000, which are 25 and 16, which are Z and Q. What we need to do is pad the last sextet with 0 and note that we have 2 octects missing. If we attempt to get our sextet groupings out of that, we get 011001 and 01. We know that Dav is encoded as RGF2 so we just need to encode the last letter, e.Į as a byte is 101, which is 01100101 in binary. To extend our previous example, let’s encode my entire first name (Dave if you already forgot…). When we lack 1 or 2 octects out of our 24 bit string, we need to pad the end of the base64 string with =. What happens when the data we want to represent isn’t divisible by three and our last grouping doesn’t have 24 bits? We just converted to Base64! Hooray! Paddingīut wait… we have a problem. Looking those up in the index table gives the string RGF2. Next, grab 4 sextets of bits, convert those to decimal and look up the corresponding character in the index table. In this instance, we’ll say the characters are encoded in ASCII. A single 24 bit string is represented by 4 encoded characters.įor instance, to start encoding the first 3 characters of my name we first have to convert the letters into bytes, and the bytes into bits. It works by grouping the bits of the data into chunks 24 bits, treating those as 4 chunks of 6 bits (sextets), converting each sextet into base10 and looking up the corresponding character for that decimal number. ![]() Here’s the index table of the most common set: Index The goal is to use a common set of characters that can be represented in most encoding schemes. The most common character set used is A-Z, a-z, 0-9, + and /, although different implementations can use different character sets. It works by converting the data into a base-64 representation and displaying it using a common character set. This is commonly used to store and transfer data over media that was designed to store and transfer only text, such as including an image in an XML document. To get started… What is Base64?īase64 is a common way to convert binary data into a text form. The encrypted data is a good candidate to Base64-encode though, if you need to store the encrypted data in a text file.Have you ever wondered what Base64 is? How it works? Why you need it? Have you ever wanted to write your own Base64 encoder? Well, my friend, you are in luck because that’s what we’re talking about today. If you need to hide your data, use encryption. Numerous tools are available to decode the data without the need for any key. If you would like to obfuscate the data, then Base64 will offer you a very poor security mechanism. Also, mail and file systems can now cope with 4 byte words containing millions of characters. Base64 encoded data might save you some trouble there. ![]() Some of those settings may contain characters that aren't allowed in the file, like encrypted passwords, html snippets or other arbitrary data. Say for example that you have an xml, unix config or java property file with settings for an application. Well, it's often used when you already have binary data and you still want to store the data in a 7 bit environment. If the last group contains two characters the encoding will have just one = character. If the last 24 bits contain only one character, that character is encoded into two characters and the last two spots will be padded with the characters =. The = character is a padding character added at the end of the encoding in case the input data is not dividable by 3. 6 bits can contain 2^6 combinations, which is 64, thus the name Base64. Each section of 6 bits is then translated into a new character in the range a-zA-Z0-9+/. Now, the resulting 24 bits are split into four sections of 6 bits instead. Since 8 bit characters consist of, well, 8 bits, Base64 encoding groups the characters into groups of three 8 bit characters, yielding 24 bits. The original RFC for Base64 was the Privacy-enhanced Electronic Mail (PEM) RFC 989 but now numerous variations exists, as well as RFC:s, like the RFC 1421, RFC 2045, RFC 3548, RFC 4848 and several other as well. This was mostly used in transfering of data across 6 or 7 bit connections. In short, Base64-encoding is a way to encode 8 bit character data in a series of 6 bit characters. ![]()
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