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Dmitry Baryshkov
nettle
Commits
0325eaf3
Commit
0325eaf3
authored
Jan 08, 2018
by
Niels Möller
Browse files
CTR mode optimizations for 16-byte block size.
parent
e09ed92e
Changes
2
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ChangeLog
View file @
0325eaf3
...
...
@@ -9,6 +9,13 @@
2018-01-08 Niels Möller <nisse@lysator.liu.se>
* ctr.c (ctr_crypt16): New function, with optimizations specific
to 16-byte block size.
(ctr_fill16): New helper function, definition depending on
WORDS_BIGENDIAN, and little endian version requiring
HAVE_BUILTIN_BSWAP64.
(ctr_crypt): Use ctr_crypt16, when appropriate.
* nettle-types.h (union nettle_block16): Add uint64_t field.
* configure.ac: Check for __builtin_bswap64, define
...
...
ctr.c
View file @
0325eaf3
...
...
@@ -62,36 +62,128 @@ ctr_fill (size_t block_size, uint8_t *ctr, size_t length, uint8_t *buffer)
return
i
;
}
#if WORDS_BIGENDIAN
# define USE_CTR_CRYPT16 1
static
void
ctr_fill16
(
uint8_t
*
ctr
,
size_t
blocks
,
uint64_t
*
buffer
)
{
uint64_t
hi
,
lo
;
hi
=
READ_UINT64
(
ctr
);
lo
=
READ_UINT64
(
ctr
+
8
);
while
(
blocks
--
>
0
)
{
*
buffer
++
=
hi
;
*
buffer
++
=
lo
;
hi
+=
!
(
++
lo
);
}
WRITE_UINT64
(
ctr
,
hi
);
WRITE_UINT64
(
ctr
+
8
,
lo
);
}
#else
/* !WORDS_BIGENDIAN */
# if HAVE_BUILTIN_BSWAP64
# define USE_CTR_CRYPT16 1
static
void
ctr_fill16
(
uint8_t
*
ctr
,
size_t
blocks
,
uint64_t
*
buffer
)
{
uint64_t
hi
,
lo
;
/* Read hi in native endianness */
hi
=
LE_READ_UINT64
(
ctr
);
lo
=
READ_UINT64
(
ctr
+
8
);
while
(
blocks
--
>
0
)
{
*
buffer
++
=
hi
;
*
buffer
++
=
__builtin_bswap64
(
lo
);
if
(
!++
lo
)
hi
=
__builtin_bswap64
(
__builtin_bswap64
(
hi
)
+
1
);
}
LE_WRITE_UINT64
(
ctr
,
hi
);
WRITE_UINT64
(
ctr
+
8
,
lo
);
}
# else
/* ! HAVE_BUILTIN_BSWAP64 */
# define USE_CTR_CRYPT16 0
# endif
#endif
/* !WORDS_BIGENDIAN */
#if USE_CTR_CRYPT16
static
size_t
ctr_crypt16
(
const
void
*
ctx
,
nettle_cipher_func
*
f
,
uint8_t
*
ctr
,
size_t
length
,
uint8_t
*
dst
,
const
uint8_t
*
src
)
{
if
(
dst
!=
src
&&
!
((
uintptr_t
)
dst
%
sizeof
(
uint64_t
)))
{
size_t
blocks
=
length
/
16u
;
ctr_fill16
(
ctr
,
blocks
,
(
uint64_t
*
)
dst
);
f
(
ctx
,
blocks
*
16
,
dst
,
dst
);
memxor
(
dst
,
src
,
blocks
*
16
);
return
blocks
*
16
;
}
else
{
/* Construct an aligned buffer of consecutive counter values, of
size at most CTR_BUFFER_LIMIT. */
TMP_DECL
(
buffer
,
union
nettle_block16
,
CTR_BUFFER_LIMIT
/
16
);
size_t
blocks
=
(
length
+
15
)
/
16u
;
size_t
i
;
TMP_ALLOC
(
buffer
,
MIN
(
blocks
,
CTR_BUFFER_LIMIT
/
16
));
for
(
i
=
0
;
blocks
>=
CTR_BUFFER_LIMIT
/
16
;
i
+=
CTR_BUFFER_LIMIT
,
blocks
-=
CTR_BUFFER_LIMIT
/
16
)
{
ctr_fill16
(
ctr
,
CTR_BUFFER_LIMIT
/
16
,
buffer
->
u64
);
f
(
ctx
,
CTR_BUFFER_LIMIT
,
buffer
->
b
,
buffer
->
b
);
if
(
length
-
i
<
CTR_BUFFER_LIMIT
)
goto
done
;
memxor3
(
dst
,
src
,
buffer
->
b
,
CTR_BUFFER_LIMIT
);
}
if
(
blocks
>
0
)
{
assert
(
length
-
i
<
CTR_BUFFER_LIMIT
);
ctr_fill16
(
ctr
,
blocks
,
buffer
->
u64
);
f
(
ctx
,
blocks
*
16
,
buffer
->
b
,
buffer
->
b
);
done:
memxor3
(
dst
+
i
,
src
+
i
,
buffer
->
b
,
length
-
i
);
}
return
length
;
}
}
#endif
/* USE_CTR_CRYPT16 */
void
ctr_crypt
(
const
void
*
ctx
,
nettle_cipher_func
*
f
,
size_t
block_size
,
uint8_t
*
ctr
,
size_t
length
,
uint8_t
*
dst
,
const
uint8_t
*
src
)
{
if
(
src
!=
dst
)
#if USE_CTR_CRYPT16
if
(
block_size
==
16
)
{
if
(
length
==
block_size
)
{
f
(
ctx
,
block_size
,
dst
,
ctr
);
INCREMENT
(
block_size
,
ctr
);
memxor
(
dst
,
src
,
block_size
);
}
else
{
size_t
filled
=
ctr_fill
(
block_size
,
ctr
,
length
,
dst
);
size_t
done
=
ctr_crypt16
(
ctx
,
f
,
ctr
,
length
,
dst
,
src
);
length
-=
done
;
src
+=
done
;
dst
+=
done
;
}
#endif
f
(
ctx
,
filled
,
dst
,
dst
);
memxor
(
dst
,
src
,
filled
);
if
(
src
!=
dst
)
{
size_t
filled
=
ctr_fill
(
block_size
,
ctr
,
length
,
dst
);
f
(
ctx
,
filled
,
dst
,
dst
);
memxor
(
dst
,
src
,
filled
);
if
(
filled
<
length
)
{
TMP_DECL
(
b
uffer
,
uint8_t
,
NETTLE_MAX_CIPHER_BLOCK_SIZE
);
TMP_ALLOC
(
b
uffer
,
block_size
);
if
(
filled
<
length
)
{
TMP_DECL
(
b
lock
,
uint8_t
,
NETTLE_MAX_CIPHER_BLOCK_SIZE
);
TMP_ALLOC
(
b
lock
,
block_size
);
f
(
ctx
,
block_size
,
buffer
,
ctr
);
INCREMENT
(
block_size
,
ctr
);
memxor3
(
dst
+
filled
,
src
+
filled
,
buffer
,
length
-
filled
);
}
f
(
ctx
,
block_size
,
block
,
ctr
);
INCREMENT
(
block_size
,
ctr
);
memxor3
(
dst
+
filled
,
src
+
filled
,
block
,
length
-
filled
);
}
}
else
...
...
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