base64_arduino

Base64 encoder/decoder for arduino repo

Installation

Add base64.cpp and base64.hpp to your project folder or library search path, put #include "base64.hpp" in your source, and pass base64.cpp to your compiler

Usage (Arduino)

There is an example Arduino sketch in the arduino-test folder.

Usage (libc)

Binary to base64 example:

unsigned char binary[] = {133, 244, 117, 206, 178, 195};
unsigned char base64[9]; // 8 bytes for output + 1 for null terminator

unsigned int base64_length = encode_base64(binary, 6, base64);

printf("%d\n", base64_length); // Prints "8"
printf((char *) base64); // Prints "hfR1zrLD"

Base64 to binary example:

unsigned char base64[] = "hfR1zrLD";
unsigned char binary[6];

unsigned int binary_length = decode_base64(base64, binary);

printf("%d\n", binary_length); // Prints "6"
printf("[%d, %d, %d, %d, %d, %d]\n", // Prints "[133, 244, 117, 206, 178, 195]"
       binary[0], binary[1], binary[2],
       binary[3], binary[4], binary[5]);

String to base64 example:

unsigned char string[] = "String example";
unsigned char base64[21]; // 20 bytes for output + 1 for null terminator

// encode_base64() places a null terminator automatically, because the output is a string
unsigned int base64_length = encode_base64(string, strlen((char *) string), base64);

printf("%d\n", base64_length); // Prints "20"
printf((char *) base64); // Prints "U3RyaW5nIGV4YW1wbGU="

Base64 to string example:

unsigned char base64[] = "U3RyaW5nIGV4YW1wbGU=";
unsigned char string[15]; // 14 bytes for output + 1 for null terminator

// decode_base64() does not place a null terminator, because the output is not always a string
unsigned int string_length = decode_base64(base64, string);
string[string_length] = '\0';

printf("%d\n", string_length); // Prints "14"
printf((char *) string); // Prints "String example"

Details

Uses common web conventions - '+' for 62, '/' for 63, '=' for padding. Note that invalid base64 characters are interpreted as padding.

Can be compiled as C, uses .*pp extensions because it is usually used in C++ projects and is tested for C++.

License