+++ /dev/null
-/* LibTomCrypt, modular cryptographic library -- Tom St Denis
- *
- * LibTomCrypt is a library that provides various cryptographic
- * algorithms in a highly modular and flexible manner.
- *
- * The library is free for all purposes without any express
- * guarantee it works.
- */
-#include "tomcrypt.h"
-
-/**
- @file lrw_process.c
- LRW_MODE implementation, Encrypt/decrypt blocks, Tom St Denis
-*/
-
-#ifdef LTC_LRW_MODE
-
-/**
- Process blocks with LRW, since decrypt/encrypt are largely the same they share this code.
- @param pt The "input" data
- @param ct [out] The "output" data
- @param len The length of the input, must be a multiple of 128-bits (16 octets)
- @param mode LRW_ENCRYPT or LRW_DECRYPT
- @param lrw The LRW state
- @return CRYPT_OK if successful
-*/
-int lrw_process(const unsigned char *pt, unsigned char *ct, unsigned long len, int mode, symmetric_LRW *lrw)
-{
- unsigned char prod[16];
- int x, err;
-#ifdef LTC_LRW_TABLES
- int y;
-#endif
-
- LTC_ARGCHK(pt != NULL);
- LTC_ARGCHK(ct != NULL);
- LTC_ARGCHK(lrw != NULL);
-
- if (len & 15) {
- return CRYPT_INVALID_ARG;
- }
-
- while (len) {
- /* copy pad */
- XMEMCPY(prod, lrw->pad, 16);
-
- /* increment IV */
- for (x = 15; x >= 0; x--) {
- lrw->IV[x] = (lrw->IV[x] + 1) & 255;
- if (lrw->IV[x]) {
- break;
- }
- }
-
- /* update pad */
-#ifdef LTC_LRW_TABLES
- /* for each byte changed we undo it's affect on the pad then add the new product */
- for (; x < 16; x++) {
-#ifdef LTC_FAST
- for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) {
- *(LTC_FAST_TYPE_PTR_CAST(lrw->pad + y)) ^= *(LTC_FAST_TYPE_PTR_CAST(&lrw->PC[x][lrw->IV[x]][y])) ^ *(LTC_FAST_TYPE_PTR_CAST(&lrw->PC[x][(lrw->IV[x]-1)&255][y]));
- }
-#else
- for (y = 0; y < 16; y++) {
- lrw->pad[y] ^= lrw->PC[x][lrw->IV[x]][y] ^ lrw->PC[x][(lrw->IV[x]-1)&255][y];
- }
-#endif
- }
-#else
- gcm_gf_mult(lrw->tweak, lrw->IV, lrw->pad);
-#endif
-
- /* xor prod */
-#ifdef LTC_FAST
- for (x = 0; x < 16; x += sizeof(LTC_FAST_TYPE)) {
- *(LTC_FAST_TYPE_PTR_CAST(ct + x)) = *(LTC_FAST_TYPE_PTR_CAST(pt + x)) ^ *(LTC_FAST_TYPE_PTR_CAST(prod + x));
- }
-#else
- for (x = 0; x < 16; x++) {
- ct[x] = pt[x] ^ prod[x];
- }
-#endif
-
- /* send through cipher */
- if (mode == LRW_ENCRYPT) {
- if ((err = cipher_descriptor[lrw->cipher].ecb_encrypt(ct, ct, &lrw->key)) != CRYPT_OK) {
- return err;
- }
- } else {
- if ((err = cipher_descriptor[lrw->cipher].ecb_decrypt(ct, ct, &lrw->key)) != CRYPT_OK) {
- return err;
- }
- }
-
- /* xor prod */
-#ifdef LTC_FAST
- for (x = 0; x < 16; x += sizeof(LTC_FAST_TYPE)) {
- *(LTC_FAST_TYPE_PTR_CAST(ct + x)) = *(LTC_FAST_TYPE_PTR_CAST(ct + x)) ^ *(LTC_FAST_TYPE_PTR_CAST(prod + x));
- }
-#else
- for (x = 0; x < 16; x++) {
- ct[x] = ct[x] ^ prod[x];
- }
-#endif
-
- /* move to next */
- pt += 16;
- ct += 16;
- len -= 16;
- }
-
- return CRYPT_OK;
-}
-
-#endif
-/* ref: $Format:%D$ */
-/* git commit: $Format:%H$ */
-/* commit time: $Format:%ai$ */