Mercurial > dropbear
view libtomcrypt/src/modes/ofb/ofb_encrypt.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 ofb_encrypt.c OFB implementation, encrypt data, Tom St Denis */ #ifdef LTC_OFB_MODE /** OFB encrypt @param pt Plaintext @param ct [out] Ciphertext @param len Length of plaintext (octets) @param ofb OFB state @return CRYPT_OK if successful */ int ofb_encrypt(const unsigned char *pt, unsigned char *ct, unsigned long len, symmetric_OFB *ofb) { int err; LTC_ARGCHK(pt != NULL); LTC_ARGCHK(ct != NULL); LTC_ARGCHK(ofb != NULL); if ((err = cipher_is_valid(ofb->cipher)) != CRYPT_OK) { return err; } /* is blocklen/padlen valid? */ if (ofb->blocklen < 0 || ofb->blocklen > (int)sizeof(ofb->IV) || ofb->padlen < 0 || ofb->padlen > (int)sizeof(ofb->IV)) { return CRYPT_INVALID_ARG; } while (len-- > 0) { if (ofb->padlen == ofb->blocklen) { if ((err = cipher_descriptor[ofb->cipher].ecb_encrypt(ofb->IV, ofb->IV, &ofb->key)) != CRYPT_OK) { return err; } ofb->padlen = 0; } *ct++ = *pt++ ^ ofb->IV[(ofb->padlen)++]; } return CRYPT_OK; } #endif /* $Source: /cvs/libtom/libtomcrypt/src/modes/ofb/ofb_encrypt.c,v $ */ /* $Revision: 1.7 $ */ /* $Date: 2006/11/26 01:45:14 $ */