base64.h

/*
 * Copyright (c) 2014 - 2021 The GmSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the GmSSL Project.
 *    (http://gmssl.org/)"
 *
 * 4. The name "GmSSL Project" must not be used to endorse or promote
 *    products derived from this software without prior written
 *    permission. For written permission, please contact
 *    guanzhi1980@gmail.com.
 *
 * 5. Products derived from this software may not be called "GmSSL"
 *    nor may "GmSSL" appear in their names without prior written
 *    permission of the GmSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the GmSSL Project
 *    (http://gmssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE GmSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE GmSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */


#ifndef GMSSL_BASE64_H
#define GMSSL_BASE64_H

#include <stdint.h>
#include <stdlib.h>

#ifdef __cplusplus
extern "C" {
#endif

/*
BASE64 Public API

	BASE64_CTX
	base64_encode_init
	base64_encode_update
	base64_encode_finish
	base64_decode_init
	base64_decode_update
	base64_decode_finish

*/


typedef struct {
    /* number saved in a partial encode/decode */
    int num;
    /*
     * The length is either the output line length (in input bytes) or the
     * shortest input line length that is ok.  Once decoding begins, the
     * length is adjusted up each time a longer line is decoded
     */
    int length;
    /* data to encode */
    unsigned char enc_data[80];
    /* number read on current line */
    int line_num;
    int expect_nl;
} BASE64_CTX;

# define BASE64_ENCODE_LENGTH(l)    (((l+2)/3*4)+(l/48+1)*2+80)
# define BASE64_DECODE_LENGTH(l)    ((l+3)/4*3+80)


void base64_encode_init(BASE64_CTX *ctx);
int  base64_encode_update(BASE64_CTX *ctx, const uint8_t *in, int inlen, uint8_t *out, int *outlen);
void base64_encode_finish(BASE64_CTX *ctx, uint8_t *out, int *outlen);

void base64_decode_init(BASE64_CTX *ctx);
int  base64_decode_update(BASE64_CTX *ctx, const uint8_t *in, int inlen, uint8_t *out, int *outlen);
int  base64_decode_finish(BASE64_CTX *ctx, uint8_t *out, int *outlen);


int base64_encode_block(unsigned char *t, const unsigned char *f, int dlen);
int base64_decode_block(unsigned char *t, const unsigned char *f, int n);


#ifdef __cplusplus
}
#endif
#endif