X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=libtomcrypt%2Fsrc%2Fmac%2Fomac%2Fomac_done.c;fp=libtomcrypt%2Fsrc%2Fmac%2Fomac%2Fomac_done.c;h=bf22523f873fb46b47616738fd4b977567286ecd;hb=66bc25938679f1d6a1d1200f329093d82a5e99b4;hp=0000000000000000000000000000000000000000;hpb=a52ee0733f420ca20224049260d6fc5cf7d8f621;p=zpackage diff --git a/libtomcrypt/src/mac/omac/omac_done.c b/libtomcrypt/src/mac/omac/omac_done.c new file mode 100644 index 0000000..bf22523 --- /dev/null +++ b/libtomcrypt/src/mac/omac/omac_done.c @@ -0,0 +1,84 @@ +/* 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 omac_done.c + OMAC1 support, terminate a stream, Tom St Denis +*/ + +#ifdef LTC_OMAC + +/** + Terminate an OMAC stream + @param omac The OMAC state + @param out [out] Destination for the authentication tag + @param outlen [in/out] The max size and resulting size of the authentication tag + @return CRYPT_OK if successful +*/ +int omac_done(omac_state *omac, unsigned char *out, unsigned long *outlen) +{ + int err, mode; + unsigned x; + + LTC_ARGCHK(omac != NULL); + LTC_ARGCHK(out != NULL); + LTC_ARGCHK(outlen != NULL); + if ((err = cipher_is_valid(omac->cipher_idx)) != CRYPT_OK) { + return err; + } + + if ((omac->buflen > (int)sizeof(omac->block)) || (omac->buflen < 0) || + (omac->blklen > (int)sizeof(omac->block)) || (omac->buflen > omac->blklen)) { + return CRYPT_INVALID_ARG; + } + + /* figure out mode */ + if (omac->buflen != omac->blklen) { + /* add the 0x80 byte */ + omac->block[omac->buflen++] = 0x80; + + /* pad with 0x00 */ + while (omac->buflen < omac->blklen) { + omac->block[omac->buflen++] = 0x00; + } + mode = 1; + } else { + mode = 0; + } + + /* now xor prev + Lu[mode] */ + for (x = 0; x < (unsigned)omac->blklen; x++) { + omac->block[x] ^= omac->prev[x] ^ omac->Lu[mode][x]; + } + + /* encrypt it */ + if ((err = cipher_descriptor[omac->cipher_idx].ecb_encrypt(omac->block, omac->block, &omac->key)) != CRYPT_OK) { + return err; + } + cipher_descriptor[omac->cipher_idx].done(&omac->key); + + /* output it */ + for (x = 0; x < (unsigned)omac->blklen && x < *outlen; x++) { + out[x] = omac->block[x]; + } + *outlen = x; + +#ifdef LTC_CLEAN_STACK + zeromem(omac, sizeof(*omac)); +#endif + return CRYPT_OK; +} + +#endif + + +/* ref: $Format:%D$ */ +/* git commit: $Format:%H$ */ +/* commit time: $Format:%ai$ */