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authorJason A. Donenfeld <Jason@zx2c4.com>2017-02-02 11:52:14 -0500
committerTheodore Ts'o <tytso@mit.edu>2017-02-02 11:52:14 -0500
commit1c83a9aab807f7452c4957b2401e1cbf43941820 (patch)
treed6c819cd48f8f88beeb6bc2ac248f5a79b0d7ed6
parentdd01b690f8f4b1e414f89e5a9a5326bf720d6652 (diff)
downloadop-kernel-dev-1c83a9aab807f7452c4957b2401e1cbf43941820.zip
op-kernel-dev-1c83a9aab807f7452c4957b2401e1cbf43941820.tar.gz
ext4: move halfmd4 into hash.c directly
The "half md4" transform should not be used by any new code. And fortunately, it's only used now by ext4. Since ext4 supports several hashing methods, at some point it might be desirable to move to something like SipHash. As an intermediate step, remove half md4 from cryptohash.h and lib, and make it just a local function in ext4's hash.c. There's precedent for doing this; the other function ext can use for its hashes -- TEA -- is also implemented in the same place. Also, by being a local function, this might allow gcc to perform some additional optimizations. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
-rw-r--r--fs/ext4/hash.c71
-rw-r--r--include/linux/cryptohash.h2
-rw-r--r--lib/Makefile2
-rw-r--r--lib/halfmd4.c67
4 files changed, 71 insertions, 71 deletions
diff --git a/fs/ext4/hash.c b/fs/ext4/hash.c
index e026aa9..38b8a96 100644
--- a/fs/ext4/hash.c
+++ b/fs/ext4/hash.c
@@ -10,7 +10,8 @@
*/
#include <linux/fs.h>
-#include <linux/cryptohash.h>
+#include <linux/compiler.h>
+#include <linux/bitops.h>
#include "ext4.h"
#define DELTA 0x9E3779B9
@@ -32,6 +33,74 @@ static void TEA_transform(__u32 buf[4], __u32 const in[])
buf[1] += b1;
}
+/* F, G and H are basic MD4 functions: selection, majority, parity */
+#define F(x, y, z) ((z) ^ ((x) & ((y) ^ (z))))
+#define G(x, y, z) (((x) & (y)) + (((x) ^ (y)) & (z)))
+#define H(x, y, z) ((x) ^ (y) ^ (z))
+
+/*
+ * The generic round function. The application is so specific that
+ * we don't bother protecting all the arguments with parens, as is generally
+ * good macro practice, in favor of extra legibility.
+ * Rotation is separate from addition to prevent recomputation
+ */
+#define ROUND(f, a, b, c, d, x, s) \
+ (a += f(b, c, d) + x, a = rol32(a, s))
+#define K1 0
+#define K2 013240474631UL
+#define K3 015666365641UL
+
+/*
+ * Basic cut-down MD4 transform. Returns only 32 bits of result.
+ */
+static __u32 half_md4_transform(__u32 buf[4], __u32 const in[8])
+{
+ __u32 a = buf[0], b = buf[1], c = buf[2], d = buf[3];
+
+ /* Round 1 */
+ ROUND(F, a, b, c, d, in[0] + K1, 3);
+ ROUND(F, d, a, b, c, in[1] + K1, 7);
+ ROUND(F, c, d, a, b, in[2] + K1, 11);
+ ROUND(F, b, c, d, a, in[3] + K1, 19);
+ ROUND(F, a, b, c, d, in[4] + K1, 3);
+ ROUND(F, d, a, b, c, in[5] + K1, 7);
+ ROUND(F, c, d, a, b, in[6] + K1, 11);
+ ROUND(F, b, c, d, a, in[7] + K1, 19);
+
+ /* Round 2 */
+ ROUND(G, a, b, c, d, in[1] + K2, 3);
+ ROUND(G, d, a, b, c, in[3] + K2, 5);
+ ROUND(G, c, d, a, b, in[5] + K2, 9);
+ ROUND(G, b, c, d, a, in[7] + K2, 13);
+ ROUND(G, a, b, c, d, in[0] + K2, 3);
+ ROUND(G, d, a, b, c, in[2] + K2, 5);
+ ROUND(G, c, d, a, b, in[4] + K2, 9);
+ ROUND(G, b, c, d, a, in[6] + K2, 13);
+
+ /* Round 3 */
+ ROUND(H, a, b, c, d, in[3] + K3, 3);
+ ROUND(H, d, a, b, c, in[7] + K3, 9);
+ ROUND(H, c, d, a, b, in[2] + K3, 11);
+ ROUND(H, b, c, d, a, in[6] + K3, 15);
+ ROUND(H, a, b, c, d, in[1] + K3, 3);
+ ROUND(H, d, a, b, c, in[5] + K3, 9);
+ ROUND(H, c, d, a, b, in[0] + K3, 11);
+ ROUND(H, b, c, d, a, in[4] + K3, 15);
+
+ buf[0] += a;
+ buf[1] += b;
+ buf[2] += c;
+ buf[3] += d;
+
+ return buf[1]; /* "most hashed" word */
+}
+#undef ROUND
+#undef K1
+#undef K2
+#undef K3
+#undef F
+#undef G
+#undef H
/* The old legacy hash */
static __u32 dx_hack_hash_unsigned(const char *name, int len)
diff --git a/include/linux/cryptohash.h b/include/linux/cryptohash.h
index f475428..3252799 100644
--- a/include/linux/cryptohash.h
+++ b/include/linux/cryptohash.h
@@ -15,6 +15,4 @@ void sha_transform(__u32 *digest, const char *data, __u32 *W);
void md5_transform(__u32 *hash, __u32 const *in);
-__u32 half_md4_transform(__u32 buf[4], __u32 const in[8]);
-
#endif
diff --git a/lib/Makefile b/lib/Makefile
index bc4073a..19ea761 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -31,7 +31,7 @@ lib-$(CONFIG_HAS_DMA) += dma-noop.o
lib-y += kobject.o klist.o
obj-y += lockref.o
-obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
+obj-y += bcd.o div64.o sort.o parser.o debug_locks.o random32.o \
bust_spinlocks.o kasprintf.o bitmap.o scatterlist.o \
gcd.o lcm.o list_sort.o uuid.o flex_array.o iov_iter.o clz_ctz.o \
bsearch.o find_bit.o llist.o memweight.o kfifo.o \
diff --git a/lib/halfmd4.c b/lib/halfmd4.c
deleted file mode 100644
index 137e861..0000000
--- a/lib/halfmd4.c
+++ /dev/null
@@ -1,67 +0,0 @@
-#include <linux/compiler.h>
-#include <linux/export.h>
-#include <linux/cryptohash.h>
-#include <linux/bitops.h>
-
-/* F, G and H are basic MD4 functions: selection, majority, parity */
-#define F(x, y, z) ((z) ^ ((x) & ((y) ^ (z))))
-#define G(x, y, z) (((x) & (y)) + (((x) ^ (y)) & (z)))
-#define H(x, y, z) ((x) ^ (y) ^ (z))
-
-/*
- * The generic round function. The application is so specific that
- * we don't bother protecting all the arguments with parens, as is generally
- * good macro practice, in favor of extra legibility.
- * Rotation is separate from addition to prevent recomputation
- */
-#define ROUND(f, a, b, c, d, x, s) \
- (a += f(b, c, d) + x, a = rol32(a, s))
-#define K1 0
-#define K2 013240474631UL
-#define K3 015666365641UL
-
-/*
- * Basic cut-down MD4 transform. Returns only 32 bits of result.
- */
-__u32 half_md4_transform(__u32 buf[4], __u32 const in[8])
-{
- __u32 a = buf[0], b = buf[1], c = buf[2], d = buf[3];
-
- /* Round 1 */
- ROUND(F, a, b, c, d, in[0] + K1, 3);
- ROUND(F, d, a, b, c, in[1] + K1, 7);
- ROUND(F, c, d, a, b, in[2] + K1, 11);
- ROUND(F, b, c, d, a, in[3] + K1, 19);
- ROUND(F, a, b, c, d, in[4] + K1, 3);
- ROUND(F, d, a, b, c, in[5] + K1, 7);
- ROUND(F, c, d, a, b, in[6] + K1, 11);
- ROUND(F, b, c, d, a, in[7] + K1, 19);
-
- /* Round 2 */
- ROUND(G, a, b, c, d, in[1] + K2, 3);
- ROUND(G, d, a, b, c, in[3] + K2, 5);
- ROUND(G, c, d, a, b, in[5] + K2, 9);
- ROUND(G, b, c, d, a, in[7] + K2, 13);
- ROUND(G, a, b, c, d, in[0] + K2, 3);
- ROUND(G, d, a, b, c, in[2] + K2, 5);
- ROUND(G, c, d, a, b, in[4] + K2, 9);
- ROUND(G, b, c, d, a, in[6] + K2, 13);
-
- /* Round 3 */
- ROUND(H, a, b, c, d, in[3] + K3, 3);
- ROUND(H, d, a, b, c, in[7] + K3, 9);
- ROUND(H, c, d, a, b, in[2] + K3, 11);
- ROUND(H, b, c, d, a, in[6] + K3, 15);
- ROUND(H, a, b, c, d, in[1] + K3, 3);
- ROUND(H, d, a, b, c, in[5] + K3, 9);
- ROUND(H, c, d, a, b, in[0] + K3, 11);
- ROUND(H, b, c, d, a, in[4] + K3, 15);
-
- buf[0] += a;
- buf[1] += b;
- buf[2] += c;
- buf[3] += d;
-
- return buf[1]; /* "most hashed" word */
-}
-EXPORT_SYMBOL(half_md4_transform);
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