Mercurial > dropbear
diff src/modes/cfb/cfb_start.c @ 191:1c15b283127b libtomcrypt-orig
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
author | Matt Johnston <matt@ucc.asn.au> |
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date | Fri, 06 May 2005 13:23:02 +0000 |
parents | |
children | 39d5d58461d6 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/modes/cfb/cfb_start.c Fri May 06 13:23:02 2005 +0000 @@ -0,0 +1,63 @@ +/* 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.org + */ +#include "tomcrypt.h" + +/** + @file cfb_start.c + CFB implementation, start chain, Tom St Denis +*/ + + +#ifdef CFB + +/** + Initialize a CFB context + @param cipher The index of the cipher desired + @param IV The initial vector + @param key The secret key + @param keylen The length of the secret key (octets) + @param num_rounds Number of rounds in the cipher desired (0 for default) + @param cfb The CFB state to initialize + @return CRYPT_OK if successful +*/ +int cfb_start(int cipher, const unsigned char *IV, const unsigned char *key, + int keylen, int num_rounds, symmetric_CFB *cfb) +{ + int x, err; + + LTC_ARGCHK(IV != NULL); + LTC_ARGCHK(key != NULL); + LTC_ARGCHK(cfb != NULL); + + if ((err = cipher_is_valid(cipher)) != CRYPT_OK) { + return err; + } + + + /* copy data */ + cfb->cipher = cipher; + cfb->blocklen = cipher_descriptor[cipher].block_length; + for (x = 0; x < cfb->blocklen; x++) + cfb->IV[x] = IV[x]; + + /* init the cipher */ + if ((err = cipher_descriptor[cipher].setup(key, keylen, num_rounds, &cfb->key)) != CRYPT_OK) { + return err; + } + + /* encrypt the IV */ + cipher_descriptor[cfb->cipher].ecb_encrypt(cfb->IV, cfb->IV, &cfb->key); + cfb->padlen = 0; + + return CRYPT_OK; +} + +#endif