+++ /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.
- */
-
-/**
- @file ocb3_add_aad.c
- OCB implementation, add AAD data, by Karel Miko
-*/
-#include "tomcrypt.h"
-
-#ifdef LTC_OCB3_MODE
-
-/**
- Add one block of AAD data (internal function)
- @param ocb The OCB state
- @param aad_block [in] AAD data (block_len size)
- @return CRYPT_OK if successful
-*/
-static int _ocb3_int_aad_add_block(ocb3_state *ocb, const unsigned char *aad_block)
-{
- unsigned char tmp[MAXBLOCKSIZE];
- int err;
-
- /* Offset_i = Offset_{i-1} xor L_{ntz(i)} */
- ocb3_int_xor_blocks(ocb->aOffset_current, ocb->aOffset_current, ocb->L_[ocb3_int_ntz(ocb->ablock_index)], ocb->block_len);
-
- /* Sum_i = Sum_{i-1} xor ENCIPHER(K, A_i xor Offset_i) */
- ocb3_int_xor_blocks(tmp, aad_block, ocb->aOffset_current, ocb->block_len);
- if ((err = cipher_descriptor[ocb->cipher].ecb_encrypt(tmp, tmp, &ocb->key)) != CRYPT_OK) {
- return err;
- }
- ocb3_int_xor_blocks(ocb->aSum_current, ocb->aSum_current, tmp, ocb->block_len);
-
- ocb->ablock_index++;
-
- return CRYPT_OK;
-}
-
-/**
- Add AAD - additional associated data
- @param ocb The OCB state
- @param aad The AAD data
- @param aadlen The size of AAD data (octets)
- @return CRYPT_OK if successful
-*/
-int ocb3_add_aad(ocb3_state *ocb, const unsigned char *aad, unsigned long aadlen)
-{
- int err, x, full_blocks, full_blocks_len, last_block_len;
- unsigned char *data;
- unsigned long datalen, l;
-
- LTC_ARGCHK(ocb != NULL);
- if (aadlen == 0) return CRYPT_OK;
- LTC_ARGCHK(aad != NULL);
-
- if (ocb->adata_buffer_bytes > 0) {
- l = ocb->block_len - ocb->adata_buffer_bytes;
- if (l > aadlen) l = aadlen;
- XMEMCPY(ocb->adata_buffer+ocb->adata_buffer_bytes, aad, l);
- ocb->adata_buffer_bytes += l;
-
- if (ocb->adata_buffer_bytes == ocb->block_len) {
- if ((err = _ocb3_int_aad_add_block(ocb, ocb->adata_buffer)) != CRYPT_OK) {
- return err;
- }
- ocb->adata_buffer_bytes = 0;
- }
-
- data = (unsigned char *)aad + l;
- datalen = aadlen - l;
- }
- else {
- data = (unsigned char *)aad;
- datalen = aadlen;
- }
-
- if (datalen == 0) return CRYPT_OK;
-
- full_blocks = datalen/ocb->block_len;
- full_blocks_len = full_blocks * ocb->block_len;
- last_block_len = datalen - full_blocks_len;
-
- for (x=0; x<full_blocks; x++) {
- if ((err = _ocb3_int_aad_add_block(ocb, data+x*ocb->block_len)) != CRYPT_OK) {
- return err;
- }
- }
-
- if (last_block_len>0) {
- XMEMCPY(ocb->adata_buffer, data+full_blocks_len, last_block_len);
- ocb->adata_buffer_bytes = last_block_len;
- }
-
- return CRYPT_OK;
-}
-
-#endif
-
-/* ref: $Format:%D$ */
-/* git commit: $Format:%H$ */
-/* commit time: $Format:%ai$ */