Decoding

Introduction A very popular way to encode binary data is Base64. The basis of this is an encoding table. As you might expect, there are 64 total characters that go into the tale. There are multiple implementations of base64 with slight differences. They are all the same except for the last two characters and line ending requirements. The first 62 characters are always “ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789”. PEM and MIME encoding are the most common and use “+/” as the last two characters....

Introduction A very common task when working with binary data in C is, converting it to and from Hex. It’s unfortunate that C doesn’t provide a standard function that can take care of this for us. However, it’s pretty easy to implement a set of functions to handle it. Hex encoding is always twice the size of binary. Since hex is base 16 we can take any unsigned char value 0-255 and represent it in two hex digits, 0x00-0xFF....