gecko/security/nss/lib/softoken/padbuf.c

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2008-06-06 05:40:11 -07:00
/* ***** 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 security libraries.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1994-2000
* 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
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "blapit.h"
#include "secport.h"
#include "secerr.h"
/*
* Prepare a buffer for any padded CBC encryption algorithm, growing to the
* appropriate boundary and filling with the appropriate padding.
* blockSize must be a power of 2.
*
* NOTE: If arena is non-NULL, we re-allocate from there, otherwise
* we assume (and use) XP memory (re)allocation.
*/
unsigned char *
CBC_PadBuffer(PRArenaPool *arena, unsigned char *inbuf, unsigned int inlen,
unsigned int *outlen, int blockSize)
{
unsigned char *outbuf;
unsigned int des_len;
unsigned int i;
unsigned char des_pad_len;
/*
* We need from 1 to blockSize bytes -- we *always* grow.
* The extra bytes contain the value of the length of the padding:
* if we have 2 bytes of padding, then the padding is "0x02, 0x02".
*/
des_len = (inlen + blockSize) & ~(blockSize - 1);
if (arena != NULL) {
outbuf = (unsigned char*)PORT_ArenaGrow (arena, inbuf, inlen, des_len);
} else {
outbuf = (unsigned char*)PORT_Realloc (inbuf, des_len);
}
if (outbuf == NULL) {
PORT_SetError (SEC_ERROR_NO_MEMORY);
return NULL;
}
des_pad_len = des_len - inlen;
for (i = inlen; i < des_len; i++)
outbuf[i] = des_pad_len;
*outlen = des_len;
return outbuf;
}