linux/crypto/vmac.c
Eric Biggers e7aefb13e6 crypto: vmac - separate tfm and request context
commit bb29648102 upstream.

syzbot reported a crash in vmac_final() when multiple threads
concurrently use the same "vmac(aes)" transform through AF_ALG.  The bug
is pretty fundamental: the VMAC template doesn't separate per-request
state from per-tfm (per-key) state like the other hash algorithms do,
but rather stores it all in the tfm context.  That's wrong.

Also, vmac_final() incorrectly zeroes most of the state including the
derived keys and cached pseudorandom pad.  Therefore, only the first
VMAC invocation with a given key calculates the correct digest.

Fix these bugs by splitting the per-tfm state from the per-request state
and using the proper init/update/final sequencing for requests.

Reproducer for the crash:

    #include <linux/if_alg.h>
    #include <sys/socket.h>
    #include <unistd.h>

    int main()
    {
            int fd;
            struct sockaddr_alg addr = {
                    .salg_type = "hash",
                    .salg_name = "vmac(aes)",
            };
            char buf[256] = { 0 };

            fd = socket(AF_ALG, SOCK_SEQPACKET, 0);
            bind(fd, (void *)&addr, sizeof(addr));
            setsockopt(fd, SOL_ALG, ALG_SET_KEY, buf, 16);
            fork();
            fd = accept(fd, NULL, NULL);
            for (;;)
                    write(fd, buf, 256);
    }

The immediate cause of the crash is that vmac_ctx_t.partial_size exceeds
VMAC_NHBYTES, causing vmac_final() to memset() a negative length.

Reported-by: syzbot+264bca3a6e8d645550d3@syzkaller.appspotmail.com
Fixes: f1939f7c56 ("crypto: vmac - New hash algorithm for intel_txt support")
Cc: <stable@vger.kernel.org> # v2.6.32+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-17 21:01:10 +02:00

675 lines
18 KiB
C

/*
* VMAC: Message Authentication Code using Universal Hashing
*
* Reference: https://tools.ietf.org/html/draft-krovetz-vmac-01
*
* Copyright (c) 2009, Intel Corporation.
* Copyright (c) 2018, Google Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
* Place - Suite 330, Boston, MA 02111-1307 USA.
*/
/*
* Derived from:
* VMAC and VHASH Implementation by Ted Krovetz (tdk@acm.org) and Wei Dai.
* This implementation is herby placed in the public domain.
* The authors offers no warranty. Use at your own risk.
* Last modified: 17 APR 08, 1700 PDT
*/
#include <asm/unaligned.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/crypto.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <asm/byteorder.h>
#include <crypto/scatterwalk.h>
#include <crypto/internal/hash.h>
/*
* User definable settings.
*/
#define VMAC_TAG_LEN 64
#define VMAC_KEY_SIZE 128/* Must be 128, 192 or 256 */
#define VMAC_KEY_LEN (VMAC_KEY_SIZE/8)
#define VMAC_NHBYTES 128/* Must 2^i for any 3 < i < 13 Standard = 128*/
/* per-transform (per-key) context */
struct vmac_tfm_ctx {
struct crypto_cipher *cipher;
u64 nhkey[(VMAC_NHBYTES/8)+2*(VMAC_TAG_LEN/64-1)];
u64 polykey[2*VMAC_TAG_LEN/64];
u64 l3key[2*VMAC_TAG_LEN/64];
};
/* per-request context */
struct vmac_desc_ctx {
union {
u8 partial[VMAC_NHBYTES]; /* partial block */
__le64 partial_words[VMAC_NHBYTES / 8];
};
unsigned int partial_size; /* size of the partial block */
bool first_block_processed;
u64 polytmp[2*VMAC_TAG_LEN/64]; /* running total of L2-hash */
};
/*
* Constants and masks
*/
#define UINT64_C(x) x##ULL
static const u64 p64 = UINT64_C(0xfffffffffffffeff); /* 2^64 - 257 prime */
static const u64 m62 = UINT64_C(0x3fffffffffffffff); /* 62-bit mask */
static const u64 m63 = UINT64_C(0x7fffffffffffffff); /* 63-bit mask */
static const u64 m64 = UINT64_C(0xffffffffffffffff); /* 64-bit mask */
static const u64 mpoly = UINT64_C(0x1fffffff1fffffff); /* Poly key mask */
#define pe64_to_cpup le64_to_cpup /* Prefer little endian */
#ifdef __LITTLE_ENDIAN
#define INDEX_HIGH 1
#define INDEX_LOW 0
#else
#define INDEX_HIGH 0
#define INDEX_LOW 1
#endif
/*
* The following routines are used in this implementation. They are
* written via macros to simulate zero-overhead call-by-reference.
*
* MUL64: 64x64->128-bit multiplication
* PMUL64: assumes top bits cleared on inputs
* ADD128: 128x128->128-bit addition
*/
#define ADD128(rh, rl, ih, il) \
do { \
u64 _il = (il); \
(rl) += (_il); \
if ((rl) < (_il)) \
(rh)++; \
(rh) += (ih); \
} while (0)
#define MUL32(i1, i2) ((u64)(u32)(i1)*(u32)(i2))
#define PMUL64(rh, rl, i1, i2) /* Assumes m doesn't overflow */ \
do { \
u64 _i1 = (i1), _i2 = (i2); \
u64 m = MUL32(_i1, _i2>>32) + MUL32(_i1>>32, _i2); \
rh = MUL32(_i1>>32, _i2>>32); \
rl = MUL32(_i1, _i2); \
ADD128(rh, rl, (m >> 32), (m << 32)); \
} while (0)
#define MUL64(rh, rl, i1, i2) \
do { \
u64 _i1 = (i1), _i2 = (i2); \
u64 m1 = MUL32(_i1, _i2>>32); \
u64 m2 = MUL32(_i1>>32, _i2); \
rh = MUL32(_i1>>32, _i2>>32); \
rl = MUL32(_i1, _i2); \
ADD128(rh, rl, (m1 >> 32), (m1 << 32)); \
ADD128(rh, rl, (m2 >> 32), (m2 << 32)); \
} while (0)
/*
* For highest performance the L1 NH and L2 polynomial hashes should be
* carefully implemented to take advantage of one's target architecture.
* Here these two hash functions are defined multiple time; once for
* 64-bit architectures, once for 32-bit SSE2 architectures, and once
* for the rest (32-bit) architectures.
* For each, nh_16 *must* be defined (works on multiples of 16 bytes).
* Optionally, nh_vmac_nhbytes can be defined (for multiples of
* VMAC_NHBYTES), and nh_16_2 and nh_vmac_nhbytes_2 (versions that do two
* NH computations at once).
*/
#ifdef CONFIG_64BIT
#define nh_16(mp, kp, nw, rh, rl) \
do { \
int i; u64 th, tl; \
rh = rl = 0; \
for (i = 0; i < nw; i += 2) { \
MUL64(th, tl, pe64_to_cpup((mp)+i)+(kp)[i], \
pe64_to_cpup((mp)+i+1)+(kp)[i+1]); \
ADD128(rh, rl, th, tl); \
} \
} while (0)
#define nh_16_2(mp, kp, nw, rh, rl, rh1, rl1) \
do { \
int i; u64 th, tl; \
rh1 = rl1 = rh = rl = 0; \
for (i = 0; i < nw; i += 2) { \
MUL64(th, tl, pe64_to_cpup((mp)+i)+(kp)[i], \
pe64_to_cpup((mp)+i+1)+(kp)[i+1]); \
ADD128(rh, rl, th, tl); \
MUL64(th, tl, pe64_to_cpup((mp)+i)+(kp)[i+2], \
pe64_to_cpup((mp)+i+1)+(kp)[i+3]); \
ADD128(rh1, rl1, th, tl); \
} \
} while (0)
#if (VMAC_NHBYTES >= 64) /* These versions do 64-bytes of message at a time */
#define nh_vmac_nhbytes(mp, kp, nw, rh, rl) \
do { \
int i; u64 th, tl; \
rh = rl = 0; \
for (i = 0; i < nw; i += 8) { \
MUL64(th, tl, pe64_to_cpup((mp)+i)+(kp)[i], \
pe64_to_cpup((mp)+i+1)+(kp)[i+1]); \
ADD128(rh, rl, th, tl); \
MUL64(th, tl, pe64_to_cpup((mp)+i+2)+(kp)[i+2], \
pe64_to_cpup((mp)+i+3)+(kp)[i+3]); \
ADD128(rh, rl, th, tl); \
MUL64(th, tl, pe64_to_cpup((mp)+i+4)+(kp)[i+4], \
pe64_to_cpup((mp)+i+5)+(kp)[i+5]); \
ADD128(rh, rl, th, tl); \
MUL64(th, tl, pe64_to_cpup((mp)+i+6)+(kp)[i+6], \
pe64_to_cpup((mp)+i+7)+(kp)[i+7]); \
ADD128(rh, rl, th, tl); \
} \
} while (0)
#define nh_vmac_nhbytes_2(mp, kp, nw, rh, rl, rh1, rl1) \
do { \
int i; u64 th, tl; \
rh1 = rl1 = rh = rl = 0; \
for (i = 0; i < nw; i += 8) { \
MUL64(th, tl, pe64_to_cpup((mp)+i)+(kp)[i], \
pe64_to_cpup((mp)+i+1)+(kp)[i+1]); \
ADD128(rh, rl, th, tl); \
MUL64(th, tl, pe64_to_cpup((mp)+i)+(kp)[i+2], \
pe64_to_cpup((mp)+i+1)+(kp)[i+3]); \
ADD128(rh1, rl1, th, tl); \
MUL64(th, tl, pe64_to_cpup((mp)+i+2)+(kp)[i+2], \
pe64_to_cpup((mp)+i+3)+(kp)[i+3]); \
ADD128(rh, rl, th, tl); \
MUL64(th, tl, pe64_to_cpup((mp)+i+2)+(kp)[i+4], \
pe64_to_cpup((mp)+i+3)+(kp)[i+5]); \
ADD128(rh1, rl1, th, tl); \
MUL64(th, tl, pe64_to_cpup((mp)+i+4)+(kp)[i+4], \
pe64_to_cpup((mp)+i+5)+(kp)[i+5]); \
ADD128(rh, rl, th, tl); \
MUL64(th, tl, pe64_to_cpup((mp)+i+4)+(kp)[i+6], \
pe64_to_cpup((mp)+i+5)+(kp)[i+7]); \
ADD128(rh1, rl1, th, tl); \
MUL64(th, tl, pe64_to_cpup((mp)+i+6)+(kp)[i+6], \
pe64_to_cpup((mp)+i+7)+(kp)[i+7]); \
ADD128(rh, rl, th, tl); \
MUL64(th, tl, pe64_to_cpup((mp)+i+6)+(kp)[i+8], \
pe64_to_cpup((mp)+i+7)+(kp)[i+9]); \
ADD128(rh1, rl1, th, tl); \
} \
} while (0)
#endif
#define poly_step(ah, al, kh, kl, mh, ml) \
do { \
u64 t1h, t1l, t2h, t2l, t3h, t3l, z = 0; \
/* compute ab*cd, put bd into result registers */ \
PMUL64(t3h, t3l, al, kh); \
PMUL64(t2h, t2l, ah, kl); \
PMUL64(t1h, t1l, ah, 2*kh); \
PMUL64(ah, al, al, kl); \
/* add 2 * ac to result */ \
ADD128(ah, al, t1h, t1l); \
/* add together ad + bc */ \
ADD128(t2h, t2l, t3h, t3l); \
/* now (ah,al), (t2l,2*t2h) need summing */ \
/* first add the high registers, carrying into t2h */ \
ADD128(t2h, ah, z, t2l); \
/* double t2h and add top bit of ah */ \
t2h = 2 * t2h + (ah >> 63); \
ah &= m63; \
/* now add the low registers */ \
ADD128(ah, al, mh, ml); \
ADD128(ah, al, z, t2h); \
} while (0)
#else /* ! CONFIG_64BIT */
#ifndef nh_16
#define nh_16(mp, kp, nw, rh, rl) \
do { \
u64 t1, t2, m1, m2, t; \
int i; \
rh = rl = t = 0; \
for (i = 0; i < nw; i += 2) { \
t1 = pe64_to_cpup(mp+i) + kp[i]; \
t2 = pe64_to_cpup(mp+i+1) + kp[i+1]; \
m2 = MUL32(t1 >> 32, t2); \
m1 = MUL32(t1, t2 >> 32); \
ADD128(rh, rl, MUL32(t1 >> 32, t2 >> 32), \
MUL32(t1, t2)); \
rh += (u64)(u32)(m1 >> 32) \
+ (u32)(m2 >> 32); \
t += (u64)(u32)m1 + (u32)m2; \
} \
ADD128(rh, rl, (t >> 32), (t << 32)); \
} while (0)
#endif
static void poly_step_func(u64 *ahi, u64 *alo,
const u64 *kh, const u64 *kl,
const u64 *mh, const u64 *ml)
{
#define a0 (*(((u32 *)alo)+INDEX_LOW))
#define a1 (*(((u32 *)alo)+INDEX_HIGH))
#define a2 (*(((u32 *)ahi)+INDEX_LOW))
#define a3 (*(((u32 *)ahi)+INDEX_HIGH))
#define k0 (*(((u32 *)kl)+INDEX_LOW))
#define k1 (*(((u32 *)kl)+INDEX_HIGH))
#define k2 (*(((u32 *)kh)+INDEX_LOW))
#define k3 (*(((u32 *)kh)+INDEX_HIGH))
u64 p, q, t;
u32 t2;
p = MUL32(a3, k3);
p += p;
p += *(u64 *)mh;
p += MUL32(a0, k2);
p += MUL32(a1, k1);
p += MUL32(a2, k0);
t = (u32)(p);
p >>= 32;
p += MUL32(a0, k3);
p += MUL32(a1, k2);
p += MUL32(a2, k1);
p += MUL32(a3, k0);
t |= ((u64)((u32)p & 0x7fffffff)) << 32;
p >>= 31;
p += (u64)(((u32 *)ml)[INDEX_LOW]);
p += MUL32(a0, k0);
q = MUL32(a1, k3);
q += MUL32(a2, k2);
q += MUL32(a3, k1);
q += q;
p += q;
t2 = (u32)(p);
p >>= 32;
p += (u64)(((u32 *)ml)[INDEX_HIGH]);
p += MUL32(a0, k1);
p += MUL32(a1, k0);
q = MUL32(a2, k3);
q += MUL32(a3, k2);
q += q;
p += q;
*(u64 *)(alo) = (p << 32) | t2;
p >>= 32;
*(u64 *)(ahi) = p + t;
#undef a0
#undef a1
#undef a2
#undef a3
#undef k0
#undef k1
#undef k2
#undef k3
}
#define poly_step(ah, al, kh, kl, mh, ml) \
poly_step_func(&(ah), &(al), &(kh), &(kl), &(mh), &(ml))
#endif /* end of specialized NH and poly definitions */
/* At least nh_16 is defined. Defined others as needed here */
#ifndef nh_16_2
#define nh_16_2(mp, kp, nw, rh, rl, rh2, rl2) \
do { \
nh_16(mp, kp, nw, rh, rl); \
nh_16(mp, ((kp)+2), nw, rh2, rl2); \
} while (0)
#endif
#ifndef nh_vmac_nhbytes
#define nh_vmac_nhbytes(mp, kp, nw, rh, rl) \
nh_16(mp, kp, nw, rh, rl)
#endif
#ifndef nh_vmac_nhbytes_2
#define nh_vmac_nhbytes_2(mp, kp, nw, rh, rl, rh2, rl2) \
do { \
nh_vmac_nhbytes(mp, kp, nw, rh, rl); \
nh_vmac_nhbytes(mp, ((kp)+2), nw, rh2, rl2); \
} while (0)
#endif
static u64 l3hash(u64 p1, u64 p2, u64 k1, u64 k2, u64 len)
{
u64 rh, rl, t, z = 0;
/* fully reduce (p1,p2)+(len,0) mod p127 */
t = p1 >> 63;
p1 &= m63;
ADD128(p1, p2, len, t);
/* At this point, (p1,p2) is at most 2^127+(len<<64) */
t = (p1 > m63) + ((p1 == m63) && (p2 == m64));
ADD128(p1, p2, z, t);
p1 &= m63;
/* compute (p1,p2)/(2^64-2^32) and (p1,p2)%(2^64-2^32) */
t = p1 + (p2 >> 32);
t += (t >> 32);
t += (u32)t > 0xfffffffeu;
p1 += (t >> 32);
p2 += (p1 << 32);
/* compute (p1+k1)%p64 and (p2+k2)%p64 */
p1 += k1;
p1 += (0 - (p1 < k1)) & 257;
p2 += k2;
p2 += (0 - (p2 < k2)) & 257;
/* compute (p1+k1)*(p2+k2)%p64 */
MUL64(rh, rl, p1, p2);
t = rh >> 56;
ADD128(t, rl, z, rh);
rh <<= 8;
ADD128(t, rl, z, rh);
t += t << 8;
rl += t;
rl += (0 - (rl < t)) & 257;
rl += (0 - (rl > p64-1)) & 257;
return rl;
}
/* L1 and L2-hash one or more VMAC_NHBYTES-byte blocks */
static void vhash_blocks(const struct vmac_tfm_ctx *tctx,
struct vmac_desc_ctx *dctx,
const __le64 *mptr, unsigned int blocks)
{
const u64 *kptr = tctx->nhkey;
const u64 pkh = tctx->polykey[0];
const u64 pkl = tctx->polykey[1];
u64 ch = dctx->polytmp[0];
u64 cl = dctx->polytmp[1];
u64 rh, rl;
if (!dctx->first_block_processed) {
dctx->first_block_processed = true;
nh_vmac_nhbytes(mptr, kptr, VMAC_NHBYTES/8, rh, rl);
rh &= m62;
ADD128(ch, cl, rh, rl);
mptr += (VMAC_NHBYTES/sizeof(u64));
blocks--;
}
while (blocks--) {
nh_vmac_nhbytes(mptr, kptr, VMAC_NHBYTES/8, rh, rl);
rh &= m62;
poly_step(ch, cl, pkh, pkl, rh, rl);
mptr += (VMAC_NHBYTES/sizeof(u64));
}
dctx->polytmp[0] = ch;
dctx->polytmp[1] = cl;
}
static int vmac_setkey(struct crypto_shash *tfm,
const u8 *key, unsigned int keylen)
{
struct vmac_tfm_ctx *tctx = crypto_shash_ctx(tfm);
__be64 out[2];
u8 in[16] = { 0 };
unsigned int i;
int err;
if (keylen != VMAC_KEY_LEN) {
crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
return -EINVAL;
}
err = crypto_cipher_setkey(tctx->cipher, key, keylen);
if (err)
return err;
/* Fill nh key */
in[0] = 0x80;
for (i = 0; i < ARRAY_SIZE(tctx->nhkey); i += 2) {
crypto_cipher_encrypt_one(tctx->cipher, (u8 *)out, in);
tctx->nhkey[i] = be64_to_cpu(out[0]);
tctx->nhkey[i+1] = be64_to_cpu(out[1]);
in[15]++;
}
/* Fill poly key */
in[0] = 0xC0;
in[15] = 0;
for (i = 0; i < ARRAY_SIZE(tctx->polykey); i += 2) {
crypto_cipher_encrypt_one(tctx->cipher, (u8 *)out, in);
tctx->polykey[i] = be64_to_cpu(out[0]) & mpoly;
tctx->polykey[i+1] = be64_to_cpu(out[1]) & mpoly;
in[15]++;
}
/* Fill ip key */
in[0] = 0xE0;
in[15] = 0;
for (i = 0; i < ARRAY_SIZE(tctx->l3key); i += 2) {
do {
crypto_cipher_encrypt_one(tctx->cipher, (u8 *)out, in);
tctx->l3key[i] = be64_to_cpu(out[0]);
tctx->l3key[i+1] = be64_to_cpu(out[1]);
in[15]++;
} while (tctx->l3key[i] >= p64 || tctx->l3key[i+1] >= p64);
}
return 0;
}
static int vmac_init(struct shash_desc *desc)
{
const struct vmac_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm);
struct vmac_desc_ctx *dctx = shash_desc_ctx(desc);
dctx->partial_size = 0;
dctx->first_block_processed = false;
memcpy(dctx->polytmp, tctx->polykey, sizeof(dctx->polytmp));
return 0;
}
static int vmac_update(struct shash_desc *desc, const u8 *p, unsigned int len)
{
const struct vmac_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm);
struct vmac_desc_ctx *dctx = shash_desc_ctx(desc);
unsigned int n;
if (dctx->partial_size) {
n = min(len, VMAC_NHBYTES - dctx->partial_size);
memcpy(&dctx->partial[dctx->partial_size], p, n);
dctx->partial_size += n;
p += n;
len -= n;
if (dctx->partial_size == VMAC_NHBYTES) {
vhash_blocks(tctx, dctx, dctx->partial_words, 1);
dctx->partial_size = 0;
}
}
if (len >= VMAC_NHBYTES) {
n = round_down(len, VMAC_NHBYTES);
/* TODO: 'p' may be misaligned here */
vhash_blocks(tctx, dctx, (const __le64 *)p, n / VMAC_NHBYTES);
p += n;
len -= n;
}
if (len) {
memcpy(dctx->partial, p, len);
dctx->partial_size = len;
}
return 0;
}
static u64 vhash_final(const struct vmac_tfm_ctx *tctx,
struct vmac_desc_ctx *dctx)
{
unsigned int partial = dctx->partial_size;
u64 ch = dctx->polytmp[0];
u64 cl = dctx->polytmp[1];
/* L1 and L2-hash the final block if needed */
if (partial) {
/* Zero-pad to next 128-bit boundary */
unsigned int n = round_up(partial, 16);
u64 rh, rl;
memset(&dctx->partial[partial], 0, n - partial);
nh_16(dctx->partial_words, tctx->nhkey, n / 8, rh, rl);
rh &= m62;
if (dctx->first_block_processed)
poly_step(ch, cl, tctx->polykey[0], tctx->polykey[1],
rh, rl);
else
ADD128(ch, cl, rh, rl);
}
/* L3-hash the 128-bit output of L2-hash */
return l3hash(ch, cl, tctx->l3key[0], tctx->l3key[1], partial * 8);
}
static int vmac_final(struct shash_desc *desc, u8 *out)
{
const struct vmac_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm);
struct vmac_desc_ctx *dctx = shash_desc_ctx(desc);
static const u8 nonce[16] = {}; /* TODO: this is insecure */
union {
u8 bytes[16];
__be64 pads[2];
} block;
int index;
u64 hash, pad;
/* Finish calculating the VHASH of the message */
hash = vhash_final(tctx, dctx);
/* Generate pseudorandom pad by encrypting the nonce */
memcpy(&block, nonce, 16);
index = block.bytes[15] & 1;
block.bytes[15] &= ~1;
crypto_cipher_encrypt_one(tctx->cipher, block.bytes, block.bytes);
pad = be64_to_cpu(block.pads[index]);
/* The VMAC is the sum of VHASH and the pseudorandom pad */
put_unaligned_le64(hash + pad, out);
return 0;
}
static int vmac_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
struct crypto_spawn *spawn = crypto_instance_ctx(inst);
struct vmac_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
struct crypto_cipher *cipher;
cipher = crypto_spawn_cipher(spawn);
if (IS_ERR(cipher))
return PTR_ERR(cipher);
tctx->cipher = cipher;
return 0;
}
static void vmac_exit_tfm(struct crypto_tfm *tfm)
{
struct vmac_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
crypto_free_cipher(tctx->cipher);
}
static int vmac_create(struct crypto_template *tmpl, struct rtattr **tb)
{
struct shash_instance *inst;
struct crypto_alg *alg;
int err;
err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
if (err)
return err;
alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
CRYPTO_ALG_TYPE_MASK);
if (IS_ERR(alg))
return PTR_ERR(alg);
err = -EINVAL;
if (alg->cra_blocksize != 16)
goto out_put_alg;
inst = shash_alloc_instance("vmac", alg);
err = PTR_ERR(inst);
if (IS_ERR(inst))
goto out_put_alg;
err = crypto_init_spawn(shash_instance_ctx(inst), alg,
shash_crypto_instance(inst),
CRYPTO_ALG_TYPE_MASK);
if (err)
goto out_free_inst;
inst->alg.base.cra_priority = alg->cra_priority;
inst->alg.base.cra_blocksize = alg->cra_blocksize;
inst->alg.base.cra_alignmask = alg->cra_alignmask;
inst->alg.base.cra_ctxsize = sizeof(struct vmac_tfm_ctx);
inst->alg.base.cra_init = vmac_init_tfm;
inst->alg.base.cra_exit = vmac_exit_tfm;
inst->alg.descsize = sizeof(struct vmac_desc_ctx);
inst->alg.digestsize = VMAC_TAG_LEN / 8;
inst->alg.init = vmac_init;
inst->alg.update = vmac_update;
inst->alg.final = vmac_final;
inst->alg.setkey = vmac_setkey;
err = shash_register_instance(tmpl, inst);
if (err) {
out_free_inst:
shash_free_instance(shash_crypto_instance(inst));
}
out_put_alg:
crypto_mod_put(alg);
return err;
}
static struct crypto_template vmac_tmpl = {
.name = "vmac",
.create = vmac_create,
.free = shash_free_instance,
.module = THIS_MODULE,
};
static int __init vmac_module_init(void)
{
return crypto_register_template(&vmac_tmpl);
}
static void __exit vmac_module_exit(void)
{
crypto_unregister_template(&vmac_tmpl);
}
module_init(vmac_module_init);
module_exit(vmac_module_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("VMAC hash algorithm");
MODULE_ALIAS_CRYPTO("vmac");