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

335 lines
10 KiB
C

/* tlsprf.c - TLS Pseudo Random Function (PRF) implementation
*
* 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 Netscape are
* Copyright (C) 1994-2000 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU General Public License Version 2 or later (the
* "GPL"), in which case the provisions of the GPL are applicable
* instead of those above. If you wish to allow use of your
* version of this file only under the terms of the GPL and not to
* allow others to use your version of this file under the MPL,
* indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by
* the GPL. If you do not delete the provisions above, a recipient
* may use your version of this file under either the MPL or the
* GPL.
*
* $Id: tlsprf.c,v 1.2 2003/02/07 23:09:35 nelsonb%netscape.com Exp $
*/
#include "pkcs11i.h"
#include "sechash.h"
#include "alghmac.h"
#define PK11_OFFSETOF(str, memb) ((PRPtrdiff)(&(((str *)0)->memb)))
#define PHASH_STATE_MAX_LEN 20
/* TLS P_hash function */
static SECStatus
pk11_P_hash(HASH_HashType hashType, const SECItem *secret, const char *label,
SECItem *seed, SECItem *result, PRBool isFIPS)
{
unsigned char state[PHASH_STATE_MAX_LEN];
unsigned char outbuf[PHASH_STATE_MAX_LEN];
unsigned int state_len = 0, label_len = 0, outbuf_len = 0, chunk_size;
unsigned int remaining;
unsigned char *res;
SECStatus status;
HMACContext *cx;
SECStatus rv = SECFailure;
const SECHashObject *hashObj = &SECRawHashObjects[hashType];
PORT_Assert((secret != NULL) && (secret->data != NULL || !secret->len));
PORT_Assert((seed != NULL) && (seed->data != NULL));
PORT_Assert((result != NULL) && (result->data != NULL));
remaining = result->len;
res = result->data;
if (label != NULL)
label_len = PORT_Strlen(label);
cx = HMAC_Create(hashObj, secret->data, secret->len, isFIPS);
if (cx == NULL)
goto loser;
/* initialize the state = A(1) = HMAC_hash(secret, seed) */
HMAC_Begin(cx);
HMAC_Update(cx, (unsigned char *)label, label_len);
HMAC_Update(cx, seed->data, seed->len);
status = HMAC_Finish(cx, state, &state_len, PHASH_STATE_MAX_LEN);
if (status != SECSuccess)
goto loser;
/* generate a block at a time until we're done */
while (remaining > 0) {
HMAC_Begin(cx);
HMAC_Update(cx, state, state_len);
if (label_len)
HMAC_Update(cx, (unsigned char *)label, label_len);
HMAC_Update(cx, seed->data, seed->len);
status = HMAC_Finish(cx, outbuf, &outbuf_len, PHASH_STATE_MAX_LEN);
if (status != SECSuccess)
goto loser;
/* Update the state = A(i) = HMAC_hash(secret, A(i-1)) */
HMAC_Begin(cx);
HMAC_Update(cx, state, state_len);
status = HMAC_Finish(cx, state, &state_len, PHASH_STATE_MAX_LEN);
if (status != SECSuccess)
goto loser;
chunk_size = PR_MIN(outbuf_len, remaining);
PORT_Memcpy(res, &outbuf, chunk_size);
res += chunk_size;
remaining -= chunk_size;
}
rv = SECSuccess;
loser:
/* if (cx) HMAC_Destroy(cx); */
/* clear out state so it's not left on the stack */
if (cx) HMAC_Destroy(cx);
PORT_Memset(state, 0, sizeof(state));
PORT_Memset(outbuf, 0, sizeof(outbuf));
return rv;
}
SECStatus
pk11_PRF(const SECItem *secret, const char *label, SECItem *seed,
SECItem *result, PRBool isFIPS)
{
SECStatus rv = SECFailure, status;
unsigned int i;
SECItem tmp = { siBuffer, NULL, 0};
SECItem S1;
SECItem S2;
PORT_Assert((secret != NULL) && (secret->data != NULL || !secret->len));
PORT_Assert((seed != NULL) && (seed->data != NULL));
PORT_Assert((result != NULL) && (result->data != NULL));
S1.type = siBuffer;
S1.len = (secret->len / 2) + (secret->len & 1);
S1.data = secret->data;
S2.type = siBuffer;
S2.len = S1.len;
S2.data = secret->data + (secret->len - S2.len);
tmp.data = (unsigned char*)PORT_Alloc(result->len);
if (tmp.data == NULL)
goto loser;
tmp.len = result->len;
status = pk11_P_hash(HASH_AlgMD5, &S1, label, seed, result, isFIPS);
if (status != SECSuccess)
goto loser;
status = pk11_P_hash(HASH_AlgSHA1, &S2, label, seed, &tmp, isFIPS);
if (status != SECSuccess)
goto loser;
for (i = 0; i < result->len; i++)
result->data[i] ^= tmp.data[i];
rv = SECSuccess;
loser:
if (tmp.data != NULL)
PORT_ZFree(tmp.data, tmp.len);
return rv;
}
static void pk11_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
pk11_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
pk11_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
pk11_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 = pk11_PRF(&secretItem, NULL, &seedItem, &sigItem, cx->cxIsFIPS);
if (rv == SECSuccess && sigLen != NULL)
*sigLen = sigItem.len;
return rv;
}
static SECStatus
pk11_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.
*/
pk11_TLSPRFHashUpdate(cx, hash, hashLen);
}
rv = pk11_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
pk11_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
pk11_TLSPRFInit(PK11SessionContext *context,
PK11Object * key,
CK_KEY_TYPE key_type)
{
PK11Attribute * 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 = pk11_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 - PK11_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 = (PK11Hash) pk11_TLSPRFHashUpdate;
context->end = (PK11End) pk11_TLSPRFEnd;
context->update = (PK11Cipher) pk11_TLSPRFUpdate;
context->verify = (PK11Verify) pk11_TLSPRFVerify;
context->destroy = (PK11Destroy) pk11_TLSPRFNull;
context->hashdestroy = (PK11Destroy) pk11_TLSPRFHashDestroy;
crv = CKR_OK;
done:
if (keyVal)
pk11_FreeAttribute(keyVal);
return crv;
}