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kernel-fxtec-pro1x/crypto/vmac.c
Daniel Borkmann 7185ad2672 crypto: memzero_explicit - make sure to clear out sensitive data 
Recently, in commit 13aa93c70e71 ("random: add and use memzero_explicit()
for clearing data"), we have found that GCC may optimize some memset()
cases away when it detects a stack variable is not being used anymore
and going out of scope. This can happen, for example, in cases when we
are clearing out sensitive information such as keying material or any
e.g. intermediate results from crypto computations, etc.

With the help of Coccinelle, we can figure out and fix such occurences
in the crypto subsytem as well. Julia Lawall provided the following
Coccinelle program:

  @@
  type T;
  identifier x;
  @@

  T x;
  ... when exists
      when any
  -memset
  +memzero_explicit
     (&x,
  -0,
     ...)
  ... when != x
      when strict

  @@
  type T;
  identifier x;
  @@

  T x[...];
  ... when exists
      when any
  -memset
  +memzero_explicit
     (x,
  -0,
     ...)
  ... when != x
      when strict

Therefore, make use of the drop-in replacement memzero_explicit() for
exactly such cases instead of using memset().

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-10-17 11:44:07 -04:00

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/*
* Modified to interface to the Linux kernel
* Copyright (c) 2009, Intel Corporation.
*
* 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.
*/
/* --------------------------------------------------------------------------
* 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.
* Please send bug reports to the authors.
* Last modified: 17 APR 08, 1700 PDT
* ----------------------------------------------------------------------- */
#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/vmac.h>
#include <crypto/internal/hash.h>
/*
* 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 void vhash_abort(struct vmac_ctx *ctx)
{
ctx->polytmp[0] = ctx->polykey[0] ;
ctx->polytmp[1] = ctx->polykey[1] ;
ctx->first_block_processed = 0;
}
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;
}
static void vhash_update(const unsigned char *m,
unsigned int mbytes, /* Pos multiple of VMAC_NHBYTES */
struct vmac_ctx *ctx)
{
u64 rh, rl, *mptr;
const u64 *kptr = (u64 *)ctx->nhkey;
int i;
u64 ch, cl;
u64 pkh = ctx->polykey[0];
u64 pkl = ctx->polykey[1];
if (!mbytes)
return;
BUG_ON(mbytes % VMAC_NHBYTES);
mptr = (u64 *)m;
i = mbytes / VMAC_NHBYTES; /* Must be non-zero */
ch = ctx->polytmp[0];
cl = ctx->polytmp[1];
if (!ctx->first_block_processed) {
ctx->first_block_processed = 1;
nh_vmac_nhbytes(mptr, kptr, VMAC_NHBYTES/8, rh, rl);
rh &= m62;
ADD128(ch, cl, rh, rl);
mptr += (VMAC_NHBYTES/sizeof(u64));
i--;
}
while (i--) {
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));
}
ctx->polytmp[0] = ch;
ctx->polytmp[1] = cl;
}
static u64 vhash(unsigned char m[], unsigned int mbytes,
u64 *tagl, struct vmac_ctx *ctx)
{
u64 rh, rl, *mptr;
const u64 *kptr = (u64 *)ctx->nhkey;
int i, remaining;
u64 ch, cl;
u64 pkh = ctx->polykey[0];
u64 pkl = ctx->polykey[1];
mptr = (u64 *)m;
i = mbytes / VMAC_NHBYTES;
remaining = mbytes % VMAC_NHBYTES;
if (ctx->first_block_processed) {
ch = ctx->polytmp[0];
cl = ctx->polytmp[1];
} else if (i) {
nh_vmac_nhbytes(mptr, kptr, VMAC_NHBYTES/8, ch, cl);
ch &= m62;
ADD128(ch, cl, pkh, pkl);
mptr += (VMAC_NHBYTES/sizeof(u64));
i--;
} else if (remaining) {
nh_16(mptr, kptr, 2*((remaining+15)/16), ch, cl);
ch &= m62;
ADD128(ch, cl, pkh, pkl);
mptr += (VMAC_NHBYTES/sizeof(u64));
goto do_l3;
} else {/* Empty String */
ch = pkh; cl = pkl;
goto do_l3;
}
while (i--) {
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));
}
if (remaining) {
nh_16(mptr, kptr, 2*((remaining+15)/16), rh, rl);
rh &= m62;
poly_step(ch, cl, pkh, pkl, rh, rl);
}
do_l3:
vhash_abort(ctx);
remaining *= 8;
return l3hash(ch, cl, ctx->l3key[0], ctx->l3key[1], remaining);
}
static u64 vmac(unsigned char m[], unsigned int mbytes,
const unsigned char n[16], u64 *tagl,
struct vmac_ctx_t *ctx)
{
u64 *in_n, *out_p;
u64 p, h;
int i;
in_n = ctx->__vmac_ctx.cached_nonce;
out_p = ctx->__vmac_ctx.cached_aes;
i = n[15] & 1;
if ((*(u64 *)(n+8) != in_n[1]) || (*(u64 *)(n) != in_n[0])) {
in_n[0] = *(u64 *)(n);
in_n[1] = *(u64 *)(n+8);
((unsigned char *)in_n)[15] &= 0xFE;
crypto_cipher_encrypt_one(ctx->child,
(unsigned char *)out_p, (unsigned char *)in_n);
((unsigned char *)in_n)[15] |= (unsigned char)(1-i);
}
p = be64_to_cpup(out_p + i);
h = vhash(m, mbytes, (u64 *)0, &ctx->__vmac_ctx);
return le64_to_cpu(p + h);
}
static int vmac_set_key(unsigned char user_key[], struct vmac_ctx_t *ctx)
{
u64 in[2] = {0}, out[2];
unsigned i;
int err = 0;
err = crypto_cipher_setkey(ctx->child, user_key, VMAC_KEY_LEN);
if (err)
return err;
/* Fill nh key */
((unsigned char *)in)[0] = 0x80;
for (i = 0; i < sizeof(ctx->__vmac_ctx.nhkey)/8; i += 2) {
crypto_cipher_encrypt_one(ctx->child,
(unsigned char *)out, (unsigned char *)in);
ctx->__vmac_ctx.nhkey[i] = be64_to_cpup(out);
ctx->__vmac_ctx.nhkey[i+1] = be64_to_cpup(out+1);
((unsigned char *)in)[15] += 1;
}
/* Fill poly key */
((unsigned char *)in)[0] = 0xC0;
in[1] = 0;
for (i = 0; i < sizeof(ctx->__vmac_ctx.polykey)/8; i += 2) {
crypto_cipher_encrypt_one(ctx->child,
(unsigned char *)out, (unsigned char *)in);
ctx->__vmac_ctx.polytmp[i] =
ctx->__vmac_ctx.polykey[i] =
be64_to_cpup(out) & mpoly;
ctx->__vmac_ctx.polytmp[i+1] =
ctx->__vmac_ctx.polykey[i+1] =
be64_to_cpup(out+1) & mpoly;
((unsigned char *)in)[15] += 1;
}
/* Fill ip key */
((unsigned char *)in)[0] = 0xE0;
in[1] = 0;
for (i = 0; i < sizeof(ctx->__vmac_ctx.l3key)/8; i += 2) {
do {
crypto_cipher_encrypt_one(ctx->child,
(unsigned char *)out, (unsigned char *)in);
ctx->__vmac_ctx.l3key[i] = be64_to_cpup(out);
ctx->__vmac_ctx.l3key[i+1] = be64_to_cpup(out+1);
((unsigned char *)in)[15] += 1;
} while (ctx->__vmac_ctx.l3key[i] >= p64
|| ctx->__vmac_ctx.l3key[i+1] >= p64);
}
/* Invalidate nonce/aes cache and reset other elements */
ctx->__vmac_ctx.cached_nonce[0] = (u64)-1; /* Ensure illegal nonce */
ctx->__vmac_ctx.cached_nonce[1] = (u64)0; /* Ensure illegal nonce */
ctx->__vmac_ctx.first_block_processed = 0;
return err;
}
static int vmac_setkey(struct crypto_shash *parent,
const u8 *key, unsigned int keylen)
{
struct vmac_ctx_t *ctx = crypto_shash_ctx(parent);
if (keylen != VMAC_KEY_LEN) {
crypto_shash_set_flags(parent, CRYPTO_TFM_RES_BAD_KEY_LEN);
return -EINVAL;
}
return vmac_set_key((u8 *)key, ctx);
}
static int vmac_init(struct shash_desc *pdesc)
{
return 0;
}
static int vmac_update(struct shash_desc *pdesc, const u8 *p,
unsigned int len)
{
struct crypto_shash *parent = pdesc->tfm;
struct vmac_ctx_t *ctx = crypto_shash_ctx(parent);
int expand;
int min;
expand = VMAC_NHBYTES - ctx->partial_size > 0 ?
VMAC_NHBYTES - ctx->partial_size : 0;
min = len < expand ? len : expand;
memcpy(ctx->partial + ctx->partial_size, p, min);
ctx->partial_size += min;
if (len < expand)
return 0;
vhash_update(ctx->partial, VMAC_NHBYTES, &ctx->__vmac_ctx);
ctx->partial_size = 0;
len -= expand;
p += expand;
if (len % VMAC_NHBYTES) {
memcpy(ctx->partial, p + len - (len % VMAC_NHBYTES),
len % VMAC_NHBYTES);
ctx->partial_size = len % VMAC_NHBYTES;
}
vhash_update(p, len - len % VMAC_NHBYTES, &ctx->__vmac_ctx);
return 0;
}
static int vmac_final(struct shash_desc *pdesc, u8 *out)
{
struct crypto_shash *parent = pdesc->tfm;
struct vmac_ctx_t *ctx = crypto_shash_ctx(parent);
vmac_t mac;
u8 nonce[16] = {};
/* vmac() ends up accessing outside the array bounds that
* we specify. In appears to access up to the next 2-word
* boundary. We'll just be uber cautious and zero the
* unwritten bytes in the buffer.
*/
if (ctx->partial_size) {
memset(ctx->partial + ctx->partial_size, 0,
VMAC_NHBYTES - ctx->partial_size);
}
mac = vmac(ctx->partial, ctx->partial_size, nonce, NULL, ctx);
memcpy(out, &mac, sizeof(vmac_t));
memzero_explicit(&mac, sizeof(vmac_t));
memset(&ctx->__vmac_ctx, 0, sizeof(struct vmac_ctx));
ctx->partial_size = 0;
return 0;
}
static int vmac_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_cipher *cipher;
struct crypto_instance *inst = (void *)tfm->__crt_alg;
struct crypto_spawn *spawn = crypto_instance_ctx(inst);
struct vmac_ctx_t *ctx = crypto_tfm_ctx(tfm);
cipher = crypto_spawn_cipher(spawn);
if (IS_ERR(cipher))
return PTR_ERR(cipher);
ctx->child = cipher;
return 0;
}
static void vmac_exit_tfm(struct crypto_tfm *tfm)
{
struct vmac_ctx_t *ctx = crypto_tfm_ctx(tfm);
crypto_free_cipher(ctx->child);
}
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);
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.digestsize = sizeof(vmac_t);
inst->alg.base.cra_ctxsize = sizeof(struct vmac_ctx_t);
inst->alg.base.cra_init = vmac_init_tfm;
inst->alg.base.cra_exit = vmac_exit_tfm;
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");
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