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Unified Diff: nss/mozilla/security/nss/lib/freebl/ctr.c

Issue 10919163: Add GCM, CTR, and CTS modes to AES. (Closed) Base URL: svn://svn.chromium.org/chrome/trunk/deps/third_party/
Patch Set: Fix comments as rsleevi suggested, fix a 32-bit bug and miscellaneous issues Created 8 years, 3 months ago
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Index: nss/mozilla/security/nss/lib/freebl/ctr.c
===================================================================
--- nss/mozilla/security/nss/lib/freebl/ctr.c (revision 0)
+++ nss/mozilla/security/nss/lib/freebl/ctr.c (revision 0)
@@ -0,0 +1,167 @@
+/* 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/. */
+
+#ifdef FREEBL_NO_DEPEND
+#include "stubs.h"
+#endif
+#include "prtypes.h"
+#include "blapit.h"
+#include "blapii.h"
+#include "ctr.h"
+#include "pkcs11t.h"
+#include "secerr.h"
+
+SECStatus
+CTR_InitContext(CTRContext *ctr, void *context, freeblCipherFunc cipher,
+ const unsigned char *param, unsigned int blocksize)
+{
+ const CK_AES_CTR_PARAMS *ctrParams = (const CK_AES_CTR_PARAMS *)param;
+
+ if (ctrParams->ulCounterBits == 0 ||
+ ctrParams->ulCounterBits > blocksize * PR_BITS_PER_BYTE) {
+ PORT_SetError(SEC_ERROR_INVALID_ARGS);
+ return SECFailure;
+ }
+
+ /* Invariant: 0 < ctr->bufPtr <= blocksize */
+ ctr->bufPtr = blocksize; /* no unused data in the buffer */
+ ctr->cipher = cipher;
+ ctr->context = context;
+ ctr->counterBits = ctrParams->ulCounterBits;
+ if (blocksize > sizeof(ctr->counter) ||
+ blocksize > sizeof(ctrParams->cb)) {
+ PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
+ return SECFailure;
+ }
+ PORT_Memcpy(ctr->counter, ctrParams->cb, blocksize);
+ return SECSuccess;
+}
+
+CTRContext *
+CTR_CreateContext(void *context, freeblCipherFunc cipher,
+ const unsigned char *param, unsigned int blocksize)
+{
+ CTRContext *ctr;
+ SECStatus rv;
+
+ /* first fill in the Counter context */
+ ctr = PORT_ZNew(CTRContext);
+ if (ctr == NULL) {
+ return NULL;
+ }
+ rv = CTR_InitContext(ctr, context, cipher, param, blocksize);
+ if (rv != SECSuccess) {
+ CTR_DestroyContext(ctr, PR_TRUE);
+ ctr = NULL;
+ }
+ return ctr;
+}
+
+void
+CTR_DestroyContext(CTRContext *ctr, PRBool freeit)
+{
+ PORT_Memset(ctr, 0, sizeof(CTRContext));
+ if (freeit) {
+ PORT_Free(ctr);
+ }
+}
+
+/*
+ * Used by counter mode. Increment the counter block. Not all bits in the
+ * counter block are part of the counter, counterBits tells how many bits
+ * are part of the counter. The counter block is blocksize long. It's a
+ * big endian value.
+ *
+ * XXX Does not handle counter rollover.
+ */
+static void
+ctr_GetNextCtr(unsigned char *counter, unsigned int counterBits,
+ unsigned int blocksize)
+{
+ unsigned char *counterPtr = counter + blocksize - 1;
+ unsigned char mask, count;
+
+ PORT_Assert(counterBits <= blocksize*PR_BITS_PER_BYTE);
+ while (counterBits >= PR_BITS_PER_BYTE) {
+ if (++(*(counterPtr--))) {
+ return;
+ }
+ counterBits -= PR_BITS_PER_BYTE;
+ }
+ if (counterBits == 0) {
+ return;
+ }
+ /* increment the final partial byte */
+ mask = (1 << counterBits)-1;
+ count = ++(*counterPtr) & mask;
+ *counterPtr = ((*counterPtr) & ~mask) | count;
+ return;
+}
+
+static void
+ctr_xor(unsigned char *target, const unsigned char *x,
+ const unsigned char *y, unsigned int count)
+{
+ unsigned int i;
+ for (i=0; i < count; i++) {
+ *target++ = *x++ ^ *y++;
+ }
+}
+
+SECStatus
+CTR_Update(CTRContext *ctr, unsigned char *outbuf,
+ unsigned int *outlen, unsigned int maxout,
+ const unsigned char *inbuf, unsigned int inlen,
+ unsigned int blocksize)
+{
+ unsigned int tmp;
+ SECStatus rv;
+
+ if (maxout < inlen) {
+ *outlen = inlen;
+ PORT_SetError(SEC_ERROR_OUTPUT_LEN);
+ return SECFailure;
+ }
+ *outlen = 0;
+ if (ctr->bufPtr != blocksize) {
+ unsigned int needed = PR_MIN(blocksize-ctr->bufPtr, inlen);
+ ctr_xor(outbuf, inbuf, ctr->buffer+ctr->bufPtr, needed);
+ ctr->bufPtr += needed;
+ outbuf += needed;
+ inbuf += needed;
+ *outlen += needed;
+ inlen -= needed;
+ if (inlen == 0) {
+ return SECSuccess;
+ }
+ PORT_Assert(ctr->bufPtr == blocksize);
+ }
+
+ while (inlen >= blocksize) {
+ rv = (*ctr->cipher)(ctr->context, ctr->buffer, &tmp, blocksize,
+ ctr->counter, blocksize, blocksize);
+ ctr_GetNextCtr(ctr->counter, ctr->counterBits, blocksize);
+ if (rv != SECSuccess) {
+ return SECFailure;
+ }
+ ctr_xor(outbuf, inbuf, ctr->buffer, blocksize);
+ outbuf += blocksize;
+ inbuf += blocksize;
+ *outlen += blocksize;
+ inlen -= blocksize;
+ }
+ if (inlen == 0) {
+ return SECSuccess;
+ }
+ rv = (*ctr->cipher)(ctr->context, ctr->buffer, &tmp, blocksize,
+ ctr->counter, blocksize, blocksize);
+ ctr_GetNextCtr(ctr->counter, ctr->counterBits, blocksize);
+ if (rv != SECSuccess) {
+ return SECFailure;
+ }
+ ctr_xor(outbuf, inbuf, ctr->buffer, inlen);
+ ctr->bufPtr = inlen;
+ *outlen += inlen;
+ return SECSuccess;
+}
Property changes on: nss/mozilla/security/nss/lib/freebl/ctr.c
___________________________________________________________________
Added: svn:eol-style
+ LF

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