/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is the Netscape Portable Runtime (NSPR).
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998-2000
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
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* decision by deleting the provisions above and replace them with the notice
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* the provisions above, a recipient may use your version of this file under
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* ***** END LICENSE BLOCK ***** */
#include "plbase64.h"
#include "prlog.h" /* For PR_NOT_REACHED */
#include "prmem.h" /* for malloc / PR_MALLOC */
#include "plstr.h" /* for PL_strlen */
static unsigned char *base = (unsigned char *)"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static void
encode3to4
(
const unsigned char *src,
unsigned char *dest
)
{
PRUint32 b32 = (PRUint32)0;
PRIntn i, j = 18;
for( i = 0; i < 3; i++ )
{
b32 <<= 8;
b32 |= (PRUint32)src[i];
}
for( i = 0; i < 4; i++ )
{
dest[i] = base[ (PRUint32)((b32>>j) & 0x3F) ];
j -= 6;
}
return;
}
static void
encode2to4
(
const unsigned char *src,
unsigned char *dest
)
{
dest[0] = base[ (PRUint32)((src[0]>>2) & 0x3F) ];
dest[1] = base[ (PRUint32)(((src[0] & 0x03) << 4) | ((src[1] >> 4) & 0x0F)) ];
dest[2] = base[ (PRUint32)((src[1] & 0x0F) << 2) ];
dest[3] = (unsigned char)'=';
return;
}
static void
encode1to4
(
const unsigned char *src,
unsigned char *dest
)
{
dest[0] = base[ (PRUint32)((src[0]>>2) & 0x3F) ];
dest[1] = base[ (PRUint32)((src[0] & 0x03) << 4) ];
dest[2] = (unsigned char)'=';
dest[3] = (unsigned char)'=';
return;
}
static void
encode
(
const unsigned char *src,
PRUint32 srclen,
unsigned char *dest
)
{
while( srclen >= 3 )
{
encode3to4(src, dest);
src += 3;
dest += 4;
srclen -= 3;
}
switch( srclen )
{
case 2:
encode2to4(src, dest);
break;
case 1:
encode1to4(src, dest);
break;
case 0:
break;
default:
PR_NOT_REACHED("coding error");
}
return;
}
/*
* PL_Base64Encode
*
* If the destination argument is NULL, a return buffer is
* allocated, and the data therein will be null-terminated.
* If the destination argument is not NULL, it is assumed to
* be of sufficient size, and the contents will not be null-
* terminated by this routine.
*
* Returns null if the allocation fails.
*/
PR_IMPLEMENT(char *)
PL_Base64Encode
(
const char *src,
PRUint32 srclen,
char *dest
)
{
if( 0 == srclen )
{
srclen = PL_strlen(src);
}
if( (char *)0 == dest )
{
PRUint32 destlen = ((srclen + 2)/3) * 4;
dest = (char *)PR_MALLOC(destlen + 1);
if( (char *)0 == dest )
{
return (char *)0;
}
dest[ destlen ] = (char)0; /* null terminate */
}
encode((const unsigned char *)src, srclen, (unsigned char *)dest);
return dest;
}
static PRInt32
codetovalue
(
unsigned char c
)
{
if( (c >= (unsigned char)'A') && (c <= (unsigned char)'Z') )
{
return (PRInt32)(c - (unsigned char)'A');
}
else if( (c >= (unsigned char)'a') && (c <= (unsigned char)'z') )
{
return ((PRInt32)(c - (unsigned char)'a') +26);
}
else if( (c >= (unsigned char)'0') && (c <= (unsigned char)'9') )
{
return ((PRInt32)(c - (unsigned char)'0') +52);
}
else if( (unsigned char)'+' == c )
{
return (PRInt32)62;
}
else if( (unsigned char)'/' == c )
{
return (PRInt32)63;
}
else
{
return -1;
}
}
static PRStatus
decode4to3
(
const unsigned char *src,
unsigned char *dest
)
{
PRUint32 b32 = (PRUint32)0;
PRInt32 bits;
PRIntn i;
for( i = 0; i < 4; i++ )
{
bits = codetovalue(src[i]);
if( bits < 0 )
{
return PR_FAILURE;
}
b32 <<= 6;
b32 |= bits;
}
dest[0] = (unsigned char)((b32 >> 16) & 0xFF);
dest[1] = (unsigned char)((b32 >> 8) & 0xFF);
dest[2] = (unsigned char)((b32 ) & 0xFF);
return PR_SUCCESS;
}
static PRStatus
decode3to2
(
const unsigned char *src,
unsigned char *dest
)
{
PRUint32 b32 = (PRUint32)0;
PRInt32 bits;
PRUint32 ubits;
bits = codetovalue(src[0]);
if( bits < 0 )
{
return PR_FAILURE;
}
b32 = (PRUint32)bits;
b32 <<= 6;
bits = codetovalue(src[1]);
if( bits < 0 )
{
return PR_FAILURE;
}
b32 |= (PRUint32)bits;
b32 <<= 4;
bits = codetovalue(src[2]);
if( bits < 0 )
{
return PR_FAILURE;
}
ubits = (PRUint32)bits;
b32 |= (ubits >> 2);
dest[0] = (unsigned char)((b32 >> 8) & 0xFF);
dest[1] = (unsigned char)((b32 ) & 0xFF);
return PR_SUCCESS;
}
static PRStatus
decode2to1
(
const unsigned char *src,
unsigned char *dest
)
{
PRUint32 b32;
PRUint32 ubits;
PRInt32 bits;
bits = codetovalue(src[0]);
if( bits < 0 )
{
return PR_FAILURE;
}
ubits = (PRUint32)bits;
b32 = (ubits << 2);
bits = codetovalue(src[1]);
if( bits < 0 )
{
return PR_FAILURE;
}
ubits = (PRUint32)bits;
b32 |= (ubits >> 4);
dest[0] = (unsigned char)b32;
return PR_SUCCESS;
}
static PRStatus
decode
(
const unsigned char *src,
PRUint32 srclen,
unsigned char *dest
)
{
PRStatus rv;
while( srclen >= 4 )
{
rv = decode4to3(src, dest);
if( PR_SUCCESS != rv )
{
return PR_FAILURE;
}
src += 4;
dest += 3;
srclen -= 4;
}
switch( srclen )
{
case 3:
rv = decode3to2(src, dest);
break;
case 2:
rv = decode2to1(src, dest);
break;
case 1:
rv = PR_FAILURE;
break;
case 0:
rv = PR_SUCCESS;
break;
default:
PR_NOT_REACHED("coding error");
}
return rv;
}
/*
* PL_Base64Decode
*
* If the destination argument is NULL, a return buffer is
* allocated and the data therein will be null-terminated.
* If the destination argument is not null, it is assumed
* to be of sufficient size, and the data will not be null-
* terminated by this routine.
*
* Returns null if the allocation fails, or if the source string is
* not well-formed.
*/
PR_IMPLEMENT(char *)
PL_Base64Decode
(
const char *src,
PRUint32 srclen,
char *dest
)
{
PRStatus status;
PRBool allocated = PR_FALSE;
if( (char *)0 == src )
{
return (char *)0;
}
if( 0 == srclen )
{
srclen = PL_strlen(src);
}
if( srclen && (0 == (srclen & 3)) )
{
if( (char)'=' == src[ srclen-1 ] )
{
if( (char)'=' == src[ srclen-2 ] )
{
srclen -= 2;
}
else
{
srclen -= 1;
}
}
}
if( (char *)0 == dest )
{
PRUint32 destlen = ((srclen * 3) / 4);
dest = (char *)PR_MALLOC(destlen + 1);
if( (char *)0 == dest )
{
return (char *)0;
}
dest[ destlen ] = (char)0; /* null terminate */
allocated = PR_TRUE;
}
status = decode((const unsigned char *)src, srclen, (unsigned char *)dest);
if( PR_SUCCESS != status )
{
if( PR_TRUE == allocated )
{
PR_DELETE(dest);
}
return (char *)0;
}
return dest;
}
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