Telodendria/src/include/Base64.h

99 lines
3.4 KiB
C

/*
* Copyright (C) 2022-2023 Jordan Bancino <@jordan:bancino.net>
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation files
* (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge,
* publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef TELODENDRIA_BASE64_H
#define TELODENDRIA_BASE64_H
/***
* @Nm Base64
* @Nd A simple base64 encoder/decoder with unpadded base64 support.
* @Dd September 30 2022
* @Xr Sha2
*
* This is an efficient yet simple base64 encoding and decoding API
* that supports regular base64, as well as the Matrix specification's
* extension to base64, called ``unpadded base64.'' This API provides
* the ability to convert between the two, instead of just implementing
* unpadded base64.
*/
#include <stddef.h>
/**
* This function computes the amount of bytes needed to store a message
* of the specified number of bytes as base64.
*/
extern size_t
Base64EncodedSize(size_t);
/**
* This function computes the amount of bytes needed to store a decoded
* representation of the encoded message. It takes a pointer to the
* encoded string because it must read a few bytes off the end in order
* to accurately compute the size.
*/
extern size_t
Base64DecodedSize(const char *, size_t);
/**
* Encode the specified number of bytes from the specified buffer as
* base64. This function returns a string on the heap that should be
* freed with
* .Fn Free ,
* or NULL if a memory allocation error ocurred.
*/
extern char *
Base64Encode(const char *, size_t);
/**
* Decode the specified number of bytes from the specified buffer of
* base64. This function returns a string on the heap that should be
* freed with
* .Fn Free ,
* or NULL if a memory allocation error occured.
*/
extern char *
Base64Decode(const char *, size_t);
/**
* Remove the padding from a specified base64 string. This function
* modifies the specified string in place. It thus has no return value
* because it cannot fail. If the passed pointer is invalid, the
* behavior is undefined.
*/
extern void
Base64Unpad(char *, size_t);
/**
* Add padding to an unpadded base64 string. This function takes a
* pointer to a pointer because it may be necessary to grow the memory
* allocated to the string. This function returns a boolean value
* indicating whether the pad operation was successful. In practice,
* this means it will only fail if a bigger string is necessary, but it
* could not be automatically allocated on the heap.
*/
extern int
Base64Pad(char **, size_t);
#endif /* TELODENDRIA_BASE64_H */