Mercurial > dropbear
view libtomcrypt/src/modes/lrw/lrw_setiv.c @ 641:2b1bb792cd4d dropbear-tfm
- Update tfm changes to current default tip
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Mon, 21 Nov 2011 19:52:28 +0800 |
parents | 0cbe8f6dbf9e |
children | f849a5ca2efc |
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/* 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. * * Tom St Denis, [email protected], http://libtomcrypt.com */ #include "tomcrypt.h" /** @file lrw_setiv.c LRW_MODE implementation, Set the current IV, Tom St Denis */ #ifdef LTC_LRW_MODE /** Set the IV for LRW @param IV The IV, must be 16 octets @param len Length ... must be 16 :-) @param lrw The LRW state to update @return CRYPT_OK if successful */ int lrw_setiv(const unsigned char *IV, unsigned long len, symmetric_LRW *lrw) { int err; #ifdef LRW_TABLES unsigned char T[16]; int x, y; #endif LTC_ARGCHK(IV != NULL); LTC_ARGCHK(lrw != NULL); if (len != 16) { return CRYPT_INVALID_ARG; } if ((err = cipher_is_valid(lrw->cipher)) != CRYPT_OK) { return err; } /* copy the IV */ XMEMCPY(lrw->IV, IV, 16); /* check if we have to actually do work */ if (cipher_descriptor[lrw->cipher].accel_lrw_encrypt != NULL && cipher_descriptor[lrw->cipher].accel_lrw_decrypt != NULL) { /* we have accelerators, let's bail since they don't use lrw->pad anyways */ return CRYPT_OK; } #ifdef LRW_TABLES XMEMCPY(T, &lrw->PC[0][IV[0]][0], 16); for (x = 1; x < 16; x++) { #ifdef LTC_FAST for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) { *((LTC_FAST_TYPE *)(T + y)) ^= *((LTC_FAST_TYPE *)(&lrw->PC[x][IV[x]][y])); } #else for (y = 0; y < 16; y++) { T[y] ^= lrw->PC[x][IV[x]][y]; } #endif } XMEMCPY(lrw->pad, T, 16); #else gcm_gf_mult(lrw->tweak, IV, lrw->pad); #endif return CRYPT_OK; } #endif /* $Source: /cvs/libtom/libtomcrypt/src/modes/lrw/lrw_setiv.c,v $ */ /* $Revision: 1.12 $ */ /* $Date: 2006/06/29 01:53:13 $ */