diff options
Diffstat (limited to 'sys/opencrypto/gmac.c')
| -rw-r--r-- | sys/opencrypto/gmac.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/sys/opencrypto/gmac.c b/sys/opencrypto/gmac.c new file mode 100644 index 0000000..402092c --- /dev/null +++ b/sys/opencrypto/gmac.c @@ -0,0 +1,119 @@ +/*- + * Copyright (c) 2014 The FreeBSD Foundation + * All rights reserved. + * + * This software was developed by John-Mark Gurney under + * the sponsorship of the FreeBSD Foundation and + * Rubicon Communications, LLC (Netgate). + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + * + */ + +#include <sys/types.h> +#include <sys/systm.h> +#include <opencrypto/gfmult.h> +#include <opencrypto/gmac.h> + +void +AES_GMAC_Init(struct aes_gmac_ctx *agc) +{ + + bzero(agc, sizeof *agc); +} + +void +AES_GMAC_Setkey(struct aes_gmac_ctx *agc, const uint8_t *key, uint16_t klen) +{ + const uint8_t zeros[GMAC_BLOCK_LEN] = {}; + struct gf128 h; + uint8_t hbuf[GMAC_BLOCK_LEN]; + + agc->rounds = rijndaelKeySetupEnc(agc->keysched, key, klen * 8); + + rijndaelEncrypt(agc->keysched, agc->rounds, zeros, hbuf); + + h = gf128_read(hbuf); + gf128_genmultable4(h, &agc->ghashtbl); + + explicit_bzero(&h, sizeof h); + explicit_bzero(hbuf, sizeof hbuf); +} + +void +AES_GMAC_Reinit(struct aes_gmac_ctx *agc, const uint8_t *iv, uint16_t ivlen) +{ + + KASSERT(ivlen <= sizeof agc->counter, ("passed ivlen too large!")); + bcopy(iv, agc->counter, ivlen); +} + +int +AES_GMAC_Update(struct aes_gmac_ctx *agc, const uint8_t *data, uint16_t len) +{ + struct gf128 v; + uint8_t buf[GMAC_BLOCK_LEN] = {}; + int i; + + v = agc->hash; + + while (len > 0) { + if (len >= 4*GMAC_BLOCK_LEN) { + i = 4*GMAC_BLOCK_LEN; + v = gf128_mul4b(v, data, &agc->ghashtbl); + } else if (len >= GMAC_BLOCK_LEN) { + i = GMAC_BLOCK_LEN; + v = gf128_add(v, gf128_read(data)); + v = gf128_mul(v, &agc->ghashtbl.tbls[0]); + } else { + i = len; + bcopy(data, buf, i); + v = gf128_add(v, gf128_read(&buf[0])); + v = gf128_mul(v, &agc->ghashtbl.tbls[0]); + explicit_bzero(buf, sizeof buf); + } + len -= i; + data += i; + } + + agc->hash = v; + explicit_bzero(&v, sizeof v); + + return (0); +} + +void +AES_GMAC_Final(uint8_t digest[GMAC_DIGEST_LEN], struct aes_gmac_ctx *agc) +{ + uint8_t enccntr[GMAC_BLOCK_LEN]; + struct gf128 a; + + /* XXX - zero additional bytes? */ + agc->counter[GMAC_BLOCK_LEN - 1] = 1; + + rijndaelEncrypt(agc->keysched, agc->rounds, agc->counter, enccntr); + a = gf128_add(agc->hash, gf128_read(enccntr)); + gf128_write(a, digest); + + explicit_bzero(enccntr, sizeof enccntr); +} |
