gecko/nsprpub/lib/libc/include/plbase64.h

77 lines
2.8 KiB
C

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef _plbase64_h
#define _plbase64_h
#include "prtypes.h"
PR_BEGIN_EXTERN_C
/*
* PL_Base64Encode
*
* This routine encodes the data pointed to by the "src" parameter using the
* base64 algorithm, and returns a pointer to the result. If the "srclen"
* parameter is not zero, it specifies the length of the source data. If it
* is zero, the source data is assumed to be null-terminated, and PL_strlen
* is used to determine the source length. If the "dest" parameter is not
* null, it is assumed to point to a buffer of sufficient size (which may be
* calculated: ((srclen + 2)/3)*4) into which the encoded data is placed
* (without any termination). If the "dest" parameter is null, a buffer is
* allocated from the heap to hold the encoded data, and the result *will*
* be terminated with an extra null character. It is the caller's
* responsibility to free the result when it is allocated. A null is returned
* if the allocation fails.
*
* NOTE: when calculating ((srclen + 2)/3)*4), first ensure that
* srclen <= (PR_UINT32_MAX/4) * 3
* to avoid PRUint32 overflow.
*/
PR_EXTERN(char *)
PL_Base64Encode
(
const char *src,
PRUint32 srclen,
char *dest
);
/*
* PL_Base64Decode
*
* This routine decodes the data pointed to by the "src" parameter using
* the base64 algorithm, and returns a pointer to the result. The source
* may either include or exclude any trailing '=' characters. If the
* "srclen" parameter is not zero, it specifies the length of the source
* data. If it is zero, PL_strlen will be used to determine the source
* length. If the "dest" parameter is not null, it is assumed to point to
* a buffer of sufficient size (which may be calculated: (srclen * 3)/4
* when srclen includes the '=' characters) into which the decoded data
* is placed (without any termination). If the "dest" parameter is null,
* a buffer is allocated from the heap to hold the decoded data, and the
* result *will* be terminated with an extra null character. It is the
* caller's responsibility to free the result when it is allocated. A null
* is retuned if the allocation fails, or if the source is not well-coded.
*
* NOTE: when calculating (srclen * 3)/4, first ensure that
* srclen <= PR_UINT32_MAX/3
* to avoid PRUint32 overflow. Alternatively, calculate
* (srclen/4) * 3 + ((srclen%4) * 3)/4
* which is equivalent but doesn't overflow for any value of srclen.
*/
PR_EXTERN(char *)
PL_Base64Decode
(
const char *src,
PRUint32 srclen,
char *dest
);
PR_END_EXTERN_C
#endif /* _plbase64_h */