From dbcea3e4c96fcd884e9cd9ab59ac21e00c359b97 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Niels=20M=C3=B6ller?= <nisse@lysator.liu.se>
Date: Thu, 23 Oct 2014 14:15:41 +0200
Subject: [PATCH] Split memxor.c into memxor.c and memxor3.c.
---
ChangeLog | 10 ++
Makefile.in | 4 +-
configure.ac | 2 +-
memxor-internal.h | 55 +++++++++++
memxor.c | 217 +----------------------------------------
memxor3.c | 240 ++++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 310 insertions(+), 218 deletions(-)
create mode 100644 memxor-internal.h
create mode 100644 memxor3.c
diff --git a/ChangeLog b/ChangeLog
index 971b6d70..a79ed616 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,15 @@
2014-10-23 Niels Möller <nisse@lysator.liu.se>
+ * configure.ac (asm_replace_list): Deleted memxor.asm, now
+ incompatible with the memxor/memxor3 split.
+
+ * memxor3.c: New file, split off from memxor.c.
+ * memxor-internal.h: New file, declarations shared by memxor.c and
+ memxor3.c.
+ * memxor.c: memxor3 fucntions moved out from this file.
+ * Makefile.in (nettle_SOURCES): Added memxor3.c.
+ (DISTFILES): Added memxor-internal.h.
+
* memxor.c (memxor_common_alignment, memxor_different_alignment)
(memxor): Change loop order, iterate from the end.
(memxor3_common_alignment): Unroll twice.
diff --git a/Makefile.in b/Makefile.in
index 10a58b0b..0d3c4246 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -109,7 +109,7 @@ nettle_SOURCES = aes-decrypt-internal.c aes-decrypt.c \
knuth-lfib.c \
md2.c md2-meta.c md4.c md4-meta.c \
md5.c md5-compress.c md5-compat.c md5-meta.c \
- memxor.c \
+ memxor.c memxor3.c \
nettle-meta-aeads.c nettle-meta-armors.c \
nettle-meta-ciphers.c nettle-meta-hashes.c \
pbkdf2.c pbkdf2-hmac-sha1.c pbkdf2-hmac-sha256.c \
@@ -216,7 +216,7 @@ DISTFILES = $(SOURCES) $(HEADERS) getopt.h getopt_int.h \
$(des_headers) descore.README \
aes-internal.h camellia-internal.h serpent-internal.h \
cast128_sboxes.h desinfo.h desCode.h \
- nettle-internal.h nettle-write.h \
+ memxor-internal.h nettle-internal.h nettle-write.h \
gmp-glue.h ecc-internal.h \
mini-gmp.h mini-gmp.c asm.m4 \
nettle.texinfo nettle.info nettle.html nettle.pdf sha-example.c
diff --git a/configure.ac b/configure.ac
index bb33962c..17e6122f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -272,7 +272,7 @@ fi
# to a new object file).
asm_replace_list="aes-encrypt-internal.asm aes-decrypt-internal.asm \
arcfour-crypt.asm camellia-crypt-internal.asm \
- md5-compress.asm memxor.asm poly1305-internal.asm \
+ md5-compress.asm poly1305-internal.asm \
chacha-core-internal.asm \
salsa20-crypt.asm salsa20-core-internal.asm \
serpent-encrypt.asm serpent-decrypt.asm \
diff --git a/memxor-internal.h b/memxor-internal.h
new file mode 100644
index 00000000..e868c181
--- /dev/null
+++ b/memxor-internal.h
@@ -0,0 +1,55 @@
+/* memxor-internal.h
+
+ Copyright (C) 2010, 2014 Niels Möller
+
+ This file is part of GNU Nettle.
+
+ GNU Nettle is free software: you can redistribute it and/or
+ modify it under the terms of either:
+
+ * the GNU Lesser General Public License as published by the Free
+ Software Foundation; either version 3 of the License, or (at your
+ option) any later version.
+
+ or
+
+ * the GNU General Public License as published by the Free
+ Software Foundation; either version 2 of the License, or (at your
+ option) any later version.
+
+ or both in parallel, as here.
+
+ GNU Nettle is distributed in the hope that 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 copies of the GNU General Public License and
+ the GNU Lesser General Public License along with this program. If
+ not, see http://www.gnu.org/licenses/.
+*/
+
+#ifndef NETTLE_MEMXOR_INTERNAL_H_INCLUDED
+#define NETTLE_MEMXOR_INTERNAL_H_INCLUDED
+
+#include "nettle-types.h"
+
+/* The word_t type is intended to be the native word size. */
+#if defined(__x86_64__) || defined(__arch64__)
+/* Including on M$ windows, where unsigned long is only 32 bits */
+typedef uint64_t word_t;
+#else
+typedef unsigned long int word_t;
+#endif
+
+#define ALIGN_OFFSET(p) ((uintptr_t) (p) % sizeof(word_t))
+
+#ifndef WORDS_BIGENDIAN
+#define MERGE(w0, sh_1, w1, sh_2) \
+ (((w0) >> (sh_1)) | ((w1) << (sh_2)))
+#else
+#define MERGE(w0, sh_1, w1, sh_2) \
+ (((w0) << (sh_1)) | ((w1) >> (sh_2)))
+#endif
+
+#endif /* NETTLE_MEMXOR_INTERNAL_H_INCLUDED */
diff --git a/memxor.c b/memxor.c
index 940da020..a252a13d 100644
--- a/memxor.c
+++ b/memxor.c
@@ -1,6 +1,6 @@
/* memxor.c
- Copyright (C) 2010 Niels Möller
+ Copyright (C) 2010, 2014 Niels Möller
This file is part of GNU Nettle.
@@ -40,24 +40,7 @@
#include <limits.h>
#include "memxor.h"
-
-/* For uintptr_t */
-#include "nettle-types.h"
-
-#if defined(__x86_64__) || defined(__arch64__)
-/* Including on M$ windows, where unsigned long is only 32 bits */
-typedef uint64_t word_t;
-#else
-typedef unsigned long int word_t;
-#endif
-
-#define ALIGN_OFFSET(p) ((uintptr_t) (p) % sizeof(word_t))
-
-#ifndef WORDS_BIGENDIAN
-#define MERGE(w0, sh_1, w1, sh_2) (((w0) >> (sh_1)) | ((w1) << (sh_2)))
-#else
-#define MERGE(w0, sh_1, w1, sh_2) (((w0) << (sh_1)) | ((w1) >> (sh_2)))
-#endif
+#include "memxor-internal.h"
#define WORD_T_THRESH 16
@@ -159,199 +142,3 @@ memxor(void *dst_in, const void *src_in, size_t n)
return dst;
}
-
-
-/* XOR word-aligned areas. n is the number of words, not bytes. */
-static void
-memxor3_common_alignment (word_t *dst,
- const word_t *a, const word_t *b, size_t n)
-{
- /* FIXME: Require n > 0? */
- if (n & 1)
- {
- n--;
- dst[n] = a[n] ^ b[n];
- }
- while (n > 0)
- {
- n -= 2;
- dst[n+1] = a[n+1] ^ b[n+1];
- dst[n] = a[n] ^ b[n];
- }
-}
-
-static void
-memxor3_different_alignment_b (word_t *dst,
- const word_t *a, const char *b, unsigned offset, size_t n)
-{
- int shl, shr;
- const word_t *b_word;
-
- word_t s0, s1;
-
- shl = CHAR_BIT * offset;
- shr = CHAR_BIT * (sizeof(word_t) - offset);
-
- b_word = (const word_t *) ((uintptr_t) b & -sizeof(word_t));
-
- if (n & 1)
- {
- n--;
- s1 = b_word[n];
- s0 = b_word[n+1];
- dst[n] = a[n] ^ MERGE (s1, shl, s0, shr);
- }
- else
- s1 = b_word[n];
-
- while (n > 0)
- {
- n -= 2;
- s0 = b_word[n+1];
- dst[n+1] = a[n+1] ^ MERGE(s0, shl, s1, shr);
- s1 = b_word[n];
- dst[n] = a[n] ^ MERGE(s1, shl, s0, shr);
- }
-}
-
-static void
-memxor3_different_alignment_ab (word_t *dst,
- const char *a, const char *b,
- unsigned offset, size_t n)
-{
- int shl, shr;
- const word_t *a_word;
- const word_t *b_word;
-
- word_t s0, s1;
-
- shl = CHAR_BIT * offset;
- shr = CHAR_BIT * (sizeof(word_t) - offset);
-
- a_word = (const word_t *) ((uintptr_t) a & -sizeof(word_t));
- b_word = (const word_t *) ((uintptr_t) b & -sizeof(word_t));
-
- if (n & 1)
- {
- n--;
- s1 = a_word[n] ^ b_word[n];
- s0 = a_word[n+1] ^ b_word[n+1];
- dst[n] = MERGE (s1, shl, s0, shr);
- }
- else
- s1 = a_word[n] ^ b_word[n];
-
- while (n > 0)
- {
- n -= 2;
- s0 = a_word[n+1] ^ b_word[n+1];
- dst[n+1] = MERGE(s0, shl, s1, shr);
- s1 = a_word[n] ^ b_word[n];
- dst[n] = MERGE(s1, shl, s0, shr);
- }
-}
-
-static void
-memxor3_different_alignment_all (word_t *dst,
- const char *a, const char *b,
- unsigned a_offset, unsigned b_offset,
- size_t n)
-{
- int al, ar, bl, br;
- const word_t *a_word;
- const word_t *b_word;
-
- word_t a0, a1, b0, b1;
-
- al = CHAR_BIT * a_offset;
- ar = CHAR_BIT * (sizeof(word_t) - a_offset);
- bl = CHAR_BIT * b_offset;
- br = CHAR_BIT * (sizeof(word_t) - b_offset);
-
- a_word = (const word_t *) ((uintptr_t) a & -sizeof(word_t));
- b_word = (const word_t *) ((uintptr_t) b & -sizeof(word_t));
-
- if (n & 1)
- {
- n--;
- a1 = a_word[n]; a0 = a_word[n+1];
- b1 = b_word[n]; b0 = b_word[n+1];
-
- dst[n] = MERGE (a1, al, a0, ar) ^ MERGE (b1, bl, b0, br);
- }
- else
- {
- a1 = a_word[n];
- b1 = b_word[n];
- }
-
- while (n > 0)
- {
- n -= 2;
- a0 = a_word[n+1]; b0 = b_word[n+1];
- dst[n+1] = MERGE(a0, al, a1, ar) ^ MERGE(b0, bl, b1, br);
- a1 = a_word[n]; b1 = b_word[n];
- dst[n] = MERGE(a1, al, a0, ar) ^ MERGE(b1, bl, b0, br);
- }
-}
-
-/* Current implementation processes data in descending order, to
- support overlapping operation with one of the sources overlapping
- the start of the destination area. This feature is used only
- internally by cbc decrypt, and it is not advertised or documented
- to nettle users. */
-void *
-memxor3(void *dst_in, const void *a_in, const void *b_in, size_t n)
-{
- char *dst = dst_in;
- const char *a = a_in;
- const char *b = b_in;
-
- if (n >= WORD_T_THRESH)
- {
- unsigned i;
- unsigned a_offset;
- unsigned b_offset;
- size_t nwords;
-
- for (i = ALIGN_OFFSET(dst + n); i > 0; i--)
- {
- n--;
- dst[n] = a[n] ^ b[n];
- }
-
- a_offset = ALIGN_OFFSET(a + n);
- b_offset = ALIGN_OFFSET(b + n);
-
- nwords = n / sizeof (word_t);
- n %= sizeof (word_t);
-
- if (a_offset == b_offset)
- {
- if (!a_offset)
- memxor3_common_alignment((word_t *) (dst + n),
- (const word_t *) (a + n),
- (const word_t *) (b + n), nwords);
- else
- memxor3_different_alignment_ab((word_t *) (dst + n),
- a + n, b + n, a_offset,
- nwords);
- }
- else if (!a_offset)
- memxor3_different_alignment_b((word_t *) (dst + n),
- (const word_t *) (a + n), b + n,
- b_offset, nwords);
- else if (!b_offset)
- memxor3_different_alignment_b((word_t *) (dst + n),
- (const word_t *) (b + n), a + n,
- a_offset, nwords);
- else
- memxor3_different_alignment_all((word_t *) (dst + n), a + n, b + n,
- a_offset, b_offset, nwords);
-
- }
- while (n-- > 0)
- dst[n] = a[n] ^ b[n];
-
- return dst;
-}
diff --git a/memxor3.c b/memxor3.c
new file mode 100644
index 00000000..06d3eca2
--- /dev/null
+++ b/memxor3.c
@@ -0,0 +1,240 @@
+/* memxor.c
+
+ Copyright (C) 2010, 2014 Niels Möller
+
+ This file is part of GNU Nettle.
+
+ GNU Nettle is free software: you can redistribute it and/or
+ modify it under the terms of either:
+
+ * the GNU Lesser General Public License as published by the Free
+ Software Foundation; either version 3 of the License, or (at your
+ option) any later version.
+
+ or
+
+ * the GNU General Public License as published by the Free
+ Software Foundation; either version 2 of the License, or (at your
+ option) any later version.
+
+ or both in parallel, as here.
+
+ GNU Nettle is distributed in the hope that 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 copies of the GNU General Public License and
+ the GNU Lesser General Public License along with this program. If
+ not, see http://www.gnu.org/licenses/.
+*/
+
+/* Implementation inspired by memcmp in glibc, contributed to the FSF
+ by Torbjorn Granlund.
+ */
+
+#if HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <limits.h>
+
+#include "memxor.h"
+#include "memxor-internal.h"
+
+#define WORD_T_THRESH 16
+
+/* XOR word-aligned areas. n is the number of words, not bytes. */
+static void
+memxor3_common_alignment (word_t *dst,
+ const word_t *a, const word_t *b, size_t n)
+{
+ /* FIXME: Require n > 0? */
+ if (n & 1)
+ {
+ n--;
+ dst[n] = a[n] ^ b[n];
+ }
+ while (n > 0)
+ {
+ n -= 2;
+ dst[n+1] = a[n+1] ^ b[n+1];
+ dst[n] = a[n] ^ b[n];
+ }
+}
+
+static void
+memxor3_different_alignment_b (word_t *dst,
+ const word_t *a, const char *b, unsigned offset, size_t n)
+{
+ int shl, shr;
+ const word_t *b_word;
+
+ word_t s0, s1;
+
+ shl = CHAR_BIT * offset;
+ shr = CHAR_BIT * (sizeof(word_t) - offset);
+
+ b_word = (const word_t *) ((uintptr_t) b & -sizeof(word_t));
+
+ if (n & 1)
+ {
+ n--;
+ s1 = b_word[n];
+ s0 = b_word[n+1];
+ dst[n] = a[n] ^ MERGE (s1, shl, s0, shr);
+ }
+ else
+ s1 = b_word[n];
+
+ while (n > 0)
+ {
+ n -= 2;
+ s0 = b_word[n+1];
+ dst[n+1] = a[n+1] ^ MERGE(s0, shl, s1, shr);
+ s1 = b_word[n];
+ dst[n] = a[n] ^ MERGE(s1, shl, s0, shr);
+ }
+}
+
+static void
+memxor3_different_alignment_ab (word_t *dst,
+ const char *a, const char *b,
+ unsigned offset, size_t n)
+{
+ int shl, shr;
+ const word_t *a_word;
+ const word_t *b_word;
+
+ word_t s0, s1;
+
+ shl = CHAR_BIT * offset;
+ shr = CHAR_BIT * (sizeof(word_t) - offset);
+
+ a_word = (const word_t *) ((uintptr_t) a & -sizeof(word_t));
+ b_word = (const word_t *) ((uintptr_t) b & -sizeof(word_t));
+
+ if (n & 1)
+ {
+ n--;
+ s1 = a_word[n] ^ b_word[n];
+ s0 = a_word[n+1] ^ b_word[n+1];
+ dst[n] = MERGE (s1, shl, s0, shr);
+ }
+ else
+ s1 = a_word[n] ^ b_word[n];
+
+ while (n > 0)
+ {
+ n -= 2;
+ s0 = a_word[n+1] ^ b_word[n+1];
+ dst[n+1] = MERGE(s0, shl, s1, shr);
+ s1 = a_word[n] ^ b_word[n];
+ dst[n] = MERGE(s1, shl, s0, shr);
+ }
+}
+
+static void
+memxor3_different_alignment_all (word_t *dst,
+ const char *a, const char *b,
+ unsigned a_offset, unsigned b_offset,
+ size_t n)
+{
+ int al, ar, bl, br;
+ const word_t *a_word;
+ const word_t *b_word;
+
+ word_t a0, a1, b0, b1;
+
+ al = CHAR_BIT * a_offset;
+ ar = CHAR_BIT * (sizeof(word_t) - a_offset);
+ bl = CHAR_BIT * b_offset;
+ br = CHAR_BIT * (sizeof(word_t) - b_offset);
+
+ a_word = (const word_t *) ((uintptr_t) a & -sizeof(word_t));
+ b_word = (const word_t *) ((uintptr_t) b & -sizeof(word_t));
+
+ if (n & 1)
+ {
+ n--;
+ a1 = a_word[n]; a0 = a_word[n+1];
+ b1 = b_word[n]; b0 = b_word[n+1];
+
+ dst[n] = MERGE (a1, al, a0, ar) ^ MERGE (b1, bl, b0, br);
+ }
+ else
+ {
+ a1 = a_word[n];
+ b1 = b_word[n];
+ }
+
+ while (n > 0)
+ {
+ n -= 2;
+ a0 = a_word[n+1]; b0 = b_word[n+1];
+ dst[n+1] = MERGE(a0, al, a1, ar) ^ MERGE(b0, bl, b1, br);
+ a1 = a_word[n]; b1 = b_word[n];
+ dst[n] = MERGE(a1, al, a0, ar) ^ MERGE(b1, bl, b0, br);
+ }
+}
+
+/* Current implementation processes data in descending order, to
+ support overlapping operation with one of the sources overlapping
+ the start of the destination area. This feature is used only
+ internally by cbc decrypt, and it is not advertised or documented
+ to nettle users. */
+void *
+memxor3(void *dst_in, const void *a_in, const void *b_in, size_t n)
+{
+ char *dst = dst_in;
+ const char *a = a_in;
+ const char *b = b_in;
+
+ if (n >= WORD_T_THRESH)
+ {
+ unsigned i;
+ unsigned a_offset;
+ unsigned b_offset;
+ size_t nwords;
+
+ for (i = ALIGN_OFFSET(dst + n); i > 0; i--)
+ {
+ n--;
+ dst[n] = a[n] ^ b[n];
+ }
+
+ a_offset = ALIGN_OFFSET(a + n);
+ b_offset = ALIGN_OFFSET(b + n);
+
+ nwords = n / sizeof (word_t);
+ n %= sizeof (word_t);
+
+ if (a_offset == b_offset)
+ {
+ if (!a_offset)
+ memxor3_common_alignment((word_t *) (dst + n),
+ (const word_t *) (a + n),
+ (const word_t *) (b + n), nwords);
+ else
+ memxor3_different_alignment_ab((word_t *) (dst + n),
+ a + n, b + n, a_offset,
+ nwords);
+ }
+ else if (!a_offset)
+ memxor3_different_alignment_b((word_t *) (dst + n),
+ (const word_t *) (a + n), b + n,
+ b_offset, nwords);
+ else if (!b_offset)
+ memxor3_different_alignment_b((word_t *) (dst + n),
+ (const word_t *) (b + n), a + n,
+ a_offset, nwords);
+ else
+ memxor3_different_alignment_all((word_t *) (dst + n), a + n, b + n,
+ a_offset, b_offset, nwords);
+
+ }
+ while (n-- > 0)
+ dst[n] = a[n] ^ b[n];
+
+ return dst;
+}
--
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