[PATCH] crypto: lib/gf128mul - Remove some bbe deadcode

linux
2024-12-11T22:02:27Z

From: "Dr. David Alan Gilbert" <linux@treblig.org>

gf128mul_4k_bbe(), gf128mul_bbe() and gf128mul_init_4k_bbe()
are part of the library originally added in 2006 by
commit c494e0705d67 ("[CRYPTO] lib: table driven multiplications in
GF(2^128)")

but have never been used.

Remove them.
(BBE is Big endian Byte/Big endian bits
Note the 64k table version is used and I've left that in)

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
---
include/crypto/gf128mul.h | 6 +---
lib/crypto/gf128mul.c | 75 ---------------------------------------
2 files changed, 1 insertion(+), 80 deletions(-)

diff --git a/include/crypto/gf128mul.h b/include/crypto/gf128mul.h
index 81330c6446f6..b0853f7cada0 100644
--- a/include/crypto/gf128mul.h
+++ b/include/crypto/gf128mul.h
@@ -158,12 +158,10 @@
64...71 72...79 80...87 88...95 96..103 104.111 112.119 120.127
*/

-/* A slow generic version of gf_mul, implemented for lle and bbe
+/* A slow generic version of gf_mul, implemented for lle
* It multiplies a and b and puts the result in a */
void gf128mul_lle(be128 *a, const be128 *b);

-void gf128mul_bbe(be128 *a, const be128 *b);
-
/*
* The following functions multiply a field element by x in
* the polynomial field representation. They use 64-bit word operations
@@ -224,9 +222,7 @@ struct gf128mul_4k {
};

struct gf128mul_4k *gf128mul_init_4k_lle(const be128 *g);
-struct gf128mul_4k *gf128mul_init_4k_bbe(const be128 *g);
void gf128mul_4k_lle(be128 *a, const struct gf128mul_4k *t);
-void gf128mul_4k_bbe(be128 *a, const struct gf128mul_4k *t);
void gf128mul_x8_ble(le128 *r, const le128 *x);
static inline void gf128mul_free_4k(struct gf128mul_4k *t)
{
diff --git a/lib/crypto/gf128mul.c b/lib/crypto/gf128mul.c
index 8f8c45e0cdcf..fbe72cb3453a 100644
--- a/lib/crypto/gf128mul.c
+++ b/lib/crypto/gf128mul.c
@@ -225,44 +225,6 @@ void gf128mul_lle(be128 *r, const be128 *b)
}
EXPORT_SYMBOL(gf128mul_lle);

-void gf128mul_bbe(be128 *r, const be128 *b)
-{
- be128 p[8];
- int i;
-
- p[0] = *r;
- for (i = 0; i < 7; ++i)
- gf128mul_x_bbe(&p[i + 1], &p[i]);
-
- memset(r, 0, sizeof(*r));
- for (i = 0;;) {
- u8 ch = ((u8 *)b)[i];
-
- if (ch & 0x80)
- be128_xor(r, r, &p[7]);
- if (ch & 0x40)
- be128_xor(r, r, &p[6]);
- if (ch & 0x20)
- be128_xor(r, r, &p[5]);
- if (ch & 0x10)
- be128_xor(r, r, &p[4]);
- if (ch & 0x08)
- be128_xor(r, r, &p[3]);
- if (ch & 0x04)
- be128_xor(r, r, &p[2]);
- if (ch & 0x02)
- be128_xor(r, r, &p[1]);
- if (ch & 0x01)
- be128_xor(r, r, &p[0]);
-
- if (++i >= 16)
- break;
-
- gf128mul_x8_bbe(r);
- }
-}
-EXPORT_SYMBOL(gf128mul_bbe);
-
/* This version uses 64k bytes of table space.
A 16 byte buffer has to be multiplied by a 16 byte key
value in GF(2^128). If we consider a GF(2^128) value in
@@ -380,28 +342,6 @@ struct gf128mul_4k *gf128mul_init_4k_lle(const be128 *g)
}
EXPORT_SYMBOL(gf128mul_init_4k_lle);

-struct gf128mul_4k *gf128mul_init_4k_bbe(const be128 *g)
-{
- struct gf128mul_4k *t;
- int j, k;
-
- t = kzalloc(sizeof(*t), GFP_KERNEL);
- if (!t)
- goto out;
-
- t->t[1] = *g;
- for (j = 1; j <= 64; j <<= 1)
- gf128mul_x_bbe(&t->t[j + j], &t->t[j]);
-
- for (j = 2; j < 256; j += j)
- for (k = 1; k < j; ++k)
- be128_xor(&t->t[j + k], &t->t[j], &t->t[k]);
-
-out:
- return t;
-}
-EXPORT_SYMBOL(gf128mul_init_4k_bbe);
-
void gf128mul_4k_lle(be128 *a, const struct gf128mul_4k *t)
{
u8 *ap = (u8 *)a;
@@ -417,20 +357,5 @@ void gf128mul_4k_lle(be128 *a, const struct gf128mul_4k *t)
}
EXPORT_SYMBOL(gf128mul_4k_lle);

-void gf128mul_4k_bbe(be128 *a, const struct gf128mul_4k *t)
-{
- u8 *ap = (u8 *)a;
- be128 r[1];
- int i = 0;
-
- *r = t->t[ap[0]];
- while (++i < 16) {
- gf128mul_x8_bbe(r);
- be128_xor(r, r, &t->t[ap[i]]);
- }
- *a = *r;
-}
-EXPORT_SYMBOL(gf128mul_4k_bbe);
-
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Functions for multiplying elements of GF(2^128)");
--
2.47.1