linux/lib/base64.c

// SPDX-License-Identifier: GPL-2.0
/*
 * base64.c - RFC4648-compliant base64 encoding
 *
 * Copyright (c) 2020 Hannes Reinecke, SUSE
 *
 * Based on the base64url routines from fs/crypto/fname.c
 * (which are using the URL-safe base64 encoding),
 * modified to use the standard coding table from RFC4648 section 4.
 */

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/export.h>
#include <linux/string.h>
#include <linux/base64.h>

static const char base64_table[65] = …;

/**
 * base64_encode() - base64-encode some binary data
 * @src: the binary data to encode
 * @srclen: the length of @src in bytes
 * @dst: (output) the base64-encoded string.  Not NUL-terminated.
 *
 * Encodes data using base64 encoding, i.e. the "Base 64 Encoding" specified
 * by RFC 4648, including the  '='-padding.
 *
 * Return: the length of the resulting base64-encoded string in bytes.
 */
int base64_encode(const u8 *src, int srclen, char *dst)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * base64_decode() - base64-decode a string
 * @src: the string to decode.  Doesn't need to be NUL-terminated.
 * @srclen: the length of @src in bytes
 * @dst: (output) the decoded binary data
 *
 * Decodes a string using base64 encoding, i.e. the "Base 64 Encoding"
 * specified by RFC 4648, including the  '='-padding.
 *
 * This implementation hasn't been optimized for performance.
 *
 * Return: the length of the resulting decoded binary data in bytes,
 *	   or -1 if the string isn't a valid base64 string.
 */
int base64_decode(const char *src, int srclen, u8 *dst)
{ … }
EXPORT_SYMBOL_GPL(…);