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

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2008-06-06 05:40:11 -07:00
/* tlsprf.c - TLS Pseudo Random Function (PRF) implementation
*
* ***** 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 ***** */
/* $Id: tlsprf.c,v 1.6 2005/08/06 09:27:28 nelsonb%netscape.com Exp $ */
#include "pkcs11i.h"
#include "blapi.h"
#define SFTK_OFFSETOF(str, memb) ((PRPtrdiff)(&(((str *)0)->memb)))
static void sftk_TLSPRFNull(void *data, PRBool freeit)
{
return;
}
typedef struct {
PRUint32 cxSize; /* size of allocated block, in bytes. */
PRUint32 cxBufSize; /* sizeof buffer at cxBufPtr. */
unsigned char *cxBufPtr; /* points to real buffer, may be cxBuf. */
PRUint32 cxKeyLen; /* bytes of cxBufPtr containing key. */
PRUint32 cxDataLen; /* bytes of cxBufPtr containing data. */
SECStatus cxRv; /* records failure of void functions. */
PRBool cxIsFIPS; /* true if conforming to FIPS 198. */
unsigned char cxBuf[512]; /* actual size may be larger than 512. */
} TLSPRFContext;
static void
sftk_TLSPRFHashUpdate(TLSPRFContext *cx, const unsigned char *data,
unsigned int data_len)
{
PRUint32 bytesUsed = cx->cxKeyLen + cx->cxDataLen;
if (cx->cxRv != SECSuccess) /* function has previously failed. */
return;
if (bytesUsed + data_len > cx->cxBufSize) {
/* We don't use realloc here because
** (a) realloc doesn't zero out the old block, and
** (b) if realloc fails, we lose the old block.
*/
PRUint32 newBufSize = bytesUsed + data_len + 512;
unsigned char * newBuf = (unsigned char *)PORT_Alloc(newBufSize);
if (!newBuf) {
cx->cxRv = SECFailure;
return;
}
PORT_Memcpy(newBuf, cx->cxBufPtr, bytesUsed);
if (cx->cxBufPtr != cx->cxBuf) {
PORT_ZFree(cx->cxBufPtr, bytesUsed);
}
cx->cxBufPtr = newBuf;
cx->cxBufSize = newBufSize;
}
PORT_Memcpy(cx->cxBufPtr + bytesUsed, data, data_len);
cx->cxDataLen += data_len;
}
static void
sftk_TLSPRFEnd(TLSPRFContext *ctx, unsigned char *hashout,
unsigned int *pDigestLen, unsigned int maxDigestLen)
{
*pDigestLen = 0; /* tells Verify that no data has been input yet. */
}
/* Compute the PRF values from the data previously input. */
static SECStatus
sftk_TLSPRFUpdate(TLSPRFContext *cx,
unsigned char *sig, /* output goes here. */
unsigned int * sigLen, /* how much output. */
unsigned int maxLen, /* output buffer size */
unsigned char *hash, /* unused. */
unsigned int hashLen) /* unused. */
{
SECStatus rv;
SECItem sigItem;
SECItem seedItem;
SECItem secretItem;
if (cx->cxRv != SECSuccess)
return cx->cxRv;
secretItem.data = cx->cxBufPtr;
secretItem.len = cx->cxKeyLen;
seedItem.data = cx->cxBufPtr + cx->cxKeyLen;
seedItem.len = cx->cxDataLen;
sigItem.data = sig;
sigItem.len = maxLen;
rv = TLS_PRF(&secretItem, NULL, &seedItem, &sigItem, cx->cxIsFIPS);
if (rv == SECSuccess && sigLen != NULL)
*sigLen = sigItem.len;
return rv;
}
static SECStatus
sftk_TLSPRFVerify(TLSPRFContext *cx,
unsigned char *sig, /* input, for comparison. */
unsigned int sigLen, /* length of sig. */
unsigned char *hash, /* data to be verified. */
unsigned int hashLen) /* size of hash data. */
{
unsigned char * tmp = (unsigned char *)PORT_Alloc(sigLen);
unsigned int tmpLen = sigLen;
SECStatus rv;
if (!tmp)
return SECFailure;
if (hashLen) {
/* hashLen is non-zero when the user does a one-step verify.
** In this case, none of the data has been input yet.
*/
sftk_TLSPRFHashUpdate(cx, hash, hashLen);
}
rv = sftk_TLSPRFUpdate(cx, tmp, &tmpLen, sigLen, NULL, 0);
if (rv == SECSuccess) {
rv = (SECStatus)(1 - !PORT_Memcmp(tmp, sig, sigLen));
}
PORT_ZFree(tmp, sigLen);
return rv;
}
static void
sftk_TLSPRFHashDestroy(TLSPRFContext *cx, PRBool freeit)
{
if (freeit) {
if (cx->cxBufPtr != cx->cxBuf)
PORT_ZFree(cx->cxBufPtr, cx->cxBufSize);
PORT_ZFree(cx, cx->cxSize);
}
}
CK_RV
sftk_TLSPRFInit(SFTKSessionContext *context,
SFTKObject * key,
CK_KEY_TYPE key_type)
{
SFTKAttribute * keyVal;
TLSPRFContext * prf_cx;
CK_RV crv = CKR_HOST_MEMORY;
PRUint32 keySize;
PRUint32 blockSize;
if (key_type != CKK_GENERIC_SECRET)
return CKR_KEY_TYPE_INCONSISTENT; /* CKR_KEY_FUNCTION_NOT_PERMITTED */
context->multi = PR_TRUE;
keyVal = sftk_FindAttribute(key, CKA_VALUE);
keySize = (!keyVal) ? 0 : keyVal->attrib.ulValueLen;
blockSize = keySize + sizeof(TLSPRFContext);
prf_cx = (TLSPRFContext *)PORT_Alloc(blockSize);
if (!prf_cx)
goto done;
prf_cx->cxSize = blockSize;
prf_cx->cxKeyLen = keySize;
prf_cx->cxDataLen = 0;
prf_cx->cxBufSize = blockSize - SFTK_OFFSETOF(TLSPRFContext, cxBuf);
prf_cx->cxRv = SECSuccess;
prf_cx->cxIsFIPS = (key->slot->slotID == FIPS_SLOT_ID);
prf_cx->cxBufPtr = prf_cx->cxBuf;
if (keySize)
PORT_Memcpy(prf_cx->cxBufPtr, keyVal->attrib.pValue, keySize);
context->hashInfo = (void *) prf_cx;
context->cipherInfo = (void *) prf_cx;
context->hashUpdate = (SFTKHash) sftk_TLSPRFHashUpdate;
context->end = (SFTKEnd) sftk_TLSPRFEnd;
context->update = (SFTKCipher) sftk_TLSPRFUpdate;
context->verify = (SFTKVerify) sftk_TLSPRFVerify;
context->destroy = (SFTKDestroy) sftk_TLSPRFNull;
context->hashdestroy = (SFTKDestroy) sftk_TLSPRFHashDestroy;
crv = CKR_OK;
done:
if (keyVal)
sftk_FreeAttribute(keyVal);
return crv;
}