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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /lib/crypto/gf128mul.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/crypto/gf128mul.c')
-rw-r--r--lib/crypto/gf128mul.c436
1 files changed, 436 insertions, 0 deletions
diff --git a/lib/crypto/gf128mul.c b/lib/crypto/gf128mul.c
new file mode 100644
index 0000000000..8f8c45e0cd
--- /dev/null
+++ b/lib/crypto/gf128mul.c
@@ -0,0 +1,436 @@
+/* gf128mul.c - GF(2^128) multiplication functions
+ *
+ * Copyright (c) 2003, Dr Brian Gladman, Worcester, UK.
+ * Copyright (c) 2006, Rik Snel <rsnel@cube.dyndns.org>
+ *
+ * Based on Dr Brian Gladman's (GPL'd) work published at
+ * http://gladman.plushost.co.uk/oldsite/cryptography_technology/index.php
+ * See the original copyright notice below.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of 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.
+ */
+
+/*
+ ---------------------------------------------------------------------------
+ Copyright (c) 2003, Dr Brian Gladman, Worcester, UK. All rights reserved.
+
+ LICENSE TERMS
+
+ The free distribution and use of this software in both source and binary
+ form is allowed (with or without changes) provided that:
+
+ 1. distributions of this source code include the above copyright
+ notice, this list of conditions and the following disclaimer;
+
+ 2. distributions in binary form include the above copyright
+ notice, this list of conditions and the following disclaimer
+ in the documentation and/or other associated materials;
+
+ 3. the copyright holder's name is not used to endorse products
+ built using this software without specific written permission.
+
+ ALTERNATIVELY, provided that this notice is retained in full, this product
+ may be distributed under the terms of the GNU General Public License (GPL),
+ in which case the provisions of the GPL apply INSTEAD OF those given above.
+
+ DISCLAIMER
+
+ This software is provided 'as is' with no explicit or implied warranties
+ in respect of its properties, including, but not limited to, correctness
+ and/or fitness for purpose.
+ ---------------------------------------------------------------------------
+ Issue 31/01/2006
+
+ This file provides fast multiplication in GF(2^128) as required by several
+ cryptographic authentication modes
+*/
+
+#include <crypto/gf128mul.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#define gf128mul_dat(q) { \
+ q(0x00), q(0x01), q(0x02), q(0x03), q(0x04), q(0x05), q(0x06), q(0x07),\
+ q(0x08), q(0x09), q(0x0a), q(0x0b), q(0x0c), q(0x0d), q(0x0e), q(0x0f),\
+ q(0x10), q(0x11), q(0x12), q(0x13), q(0x14), q(0x15), q(0x16), q(0x17),\
+ q(0x18), q(0x19), q(0x1a), q(0x1b), q(0x1c), q(0x1d), q(0x1e), q(0x1f),\
+ q(0x20), q(0x21), q(0x22), q(0x23), q(0x24), q(0x25), q(0x26), q(0x27),\
+ q(0x28), q(0x29), q(0x2a), q(0x2b), q(0x2c), q(0x2d), q(0x2e), q(0x2f),\
+ q(0x30), q(0x31), q(0x32), q(0x33), q(0x34), q(0x35), q(0x36), q(0x37),\
+ q(0x38), q(0x39), q(0x3a), q(0x3b), q(0x3c), q(0x3d), q(0x3e), q(0x3f),\
+ q(0x40), q(0x41), q(0x42), q(0x43), q(0x44), q(0x45), q(0x46), q(0x47),\
+ q(0x48), q(0x49), q(0x4a), q(0x4b), q(0x4c), q(0x4d), q(0x4e), q(0x4f),\
+ q(0x50), q(0x51), q(0x52), q(0x53), q(0x54), q(0x55), q(0x56), q(0x57),\
+ q(0x58), q(0x59), q(0x5a), q(0x5b), q(0x5c), q(0x5d), q(0x5e), q(0x5f),\
+ q(0x60), q(0x61), q(0x62), q(0x63), q(0x64), q(0x65), q(0x66), q(0x67),\
+ q(0x68), q(0x69), q(0x6a), q(0x6b), q(0x6c), q(0x6d), q(0x6e), q(0x6f),\
+ q(0x70), q(0x71), q(0x72), q(0x73), q(0x74), q(0x75), q(0x76), q(0x77),\
+ q(0x78), q(0x79), q(0x7a), q(0x7b), q(0x7c), q(0x7d), q(0x7e), q(0x7f),\
+ q(0x80), q(0x81), q(0x82), q(0x83), q(0x84), q(0x85), q(0x86), q(0x87),\
+ q(0x88), q(0x89), q(0x8a), q(0x8b), q(0x8c), q(0x8d), q(0x8e), q(0x8f),\
+ q(0x90), q(0x91), q(0x92), q(0x93), q(0x94), q(0x95), q(0x96), q(0x97),\
+ q(0x98), q(0x99), q(0x9a), q(0x9b), q(0x9c), q(0x9d), q(0x9e), q(0x9f),\
+ q(0xa0), q(0xa1), q(0xa2), q(0xa3), q(0xa4), q(0xa5), q(0xa6), q(0xa7),\
+ q(0xa8), q(0xa9), q(0xaa), q(0xab), q(0xac), q(0xad), q(0xae), q(0xaf),\
+ q(0xb0), q(0xb1), q(0xb2), q(0xb3), q(0xb4), q(0xb5), q(0xb6), q(0xb7),\
+ q(0xb8), q(0xb9), q(0xba), q(0xbb), q(0xbc), q(0xbd), q(0xbe), q(0xbf),\
+ q(0xc0), q(0xc1), q(0xc2), q(0xc3), q(0xc4), q(0xc5), q(0xc6), q(0xc7),\
+ q(0xc8), q(0xc9), q(0xca), q(0xcb), q(0xcc), q(0xcd), q(0xce), q(0xcf),\
+ q(0xd0), q(0xd1), q(0xd2), q(0xd3), q(0xd4), q(0xd5), q(0xd6), q(0xd7),\
+ q(0xd8), q(0xd9), q(0xda), q(0xdb), q(0xdc), q(0xdd), q(0xde), q(0xdf),\
+ q(0xe0), q(0xe1), q(0xe2), q(0xe3), q(0xe4), q(0xe5), q(0xe6), q(0xe7),\
+ q(0xe8), q(0xe9), q(0xea), q(0xeb), q(0xec), q(0xed), q(0xee), q(0xef),\
+ q(0xf0), q(0xf1), q(0xf2), q(0xf3), q(0xf4), q(0xf5), q(0xf6), q(0xf7),\
+ q(0xf8), q(0xf9), q(0xfa), q(0xfb), q(0xfc), q(0xfd), q(0xfe), q(0xff) \
+}
+
+/*
+ * Given a value i in 0..255 as the byte overflow when a field element
+ * in GF(2^128) is multiplied by x^8, the following macro returns the
+ * 16-bit value that must be XOR-ed into the low-degree end of the
+ * product to reduce it modulo the polynomial x^128 + x^7 + x^2 + x + 1.
+ *
+ * There are two versions of the macro, and hence two tables: one for
+ * the "be" convention where the highest-order bit is the coefficient of
+ * the highest-degree polynomial term, and one for the "le" convention
+ * where the highest-order bit is the coefficient of the lowest-degree
+ * polynomial term. In both cases the values are stored in CPU byte
+ * endianness such that the coefficients are ordered consistently across
+ * bytes, i.e. in the "be" table bits 15..0 of the stored value
+ * correspond to the coefficients of x^15..x^0, and in the "le" table
+ * bits 15..0 correspond to the coefficients of x^0..x^15.
+ *
+ * Therefore, provided that the appropriate byte endianness conversions
+ * are done by the multiplication functions (and these must be in place
+ * anyway to support both little endian and big endian CPUs), the "be"
+ * table can be used for multiplications of both "bbe" and "ble"
+ * elements, and the "le" table can be used for multiplications of both
+ * "lle" and "lbe" elements.
+ */
+
+#define xda_be(i) ( \
+ (i & 0x80 ? 0x4380 : 0) ^ (i & 0x40 ? 0x21c0 : 0) ^ \
+ (i & 0x20 ? 0x10e0 : 0) ^ (i & 0x10 ? 0x0870 : 0) ^ \
+ (i & 0x08 ? 0x0438 : 0) ^ (i & 0x04 ? 0x021c : 0) ^ \
+ (i & 0x02 ? 0x010e : 0) ^ (i & 0x01 ? 0x0087 : 0) \
+)
+
+#define xda_le(i) ( \
+ (i & 0x80 ? 0xe100 : 0) ^ (i & 0x40 ? 0x7080 : 0) ^ \
+ (i & 0x20 ? 0x3840 : 0) ^ (i & 0x10 ? 0x1c20 : 0) ^ \
+ (i & 0x08 ? 0x0e10 : 0) ^ (i & 0x04 ? 0x0708 : 0) ^ \
+ (i & 0x02 ? 0x0384 : 0) ^ (i & 0x01 ? 0x01c2 : 0) \
+)
+
+static const u16 gf128mul_table_le[256] = gf128mul_dat(xda_le);
+static const u16 gf128mul_table_be[256] = gf128mul_dat(xda_be);
+
+/*
+ * The following functions multiply a field element by x^8 in
+ * the polynomial field representation. They use 64-bit word operations
+ * to gain speed but compensate for machine endianness and hence work
+ * correctly on both styles of machine.
+ */
+
+static void gf128mul_x8_lle(be128 *x)
+{
+ u64 a = be64_to_cpu(x->a);
+ u64 b = be64_to_cpu(x->b);
+ u64 _tt = gf128mul_table_le[b & 0xff];
+
+ x->b = cpu_to_be64((b >> 8) | (a << 56));
+ x->a = cpu_to_be64((a >> 8) ^ (_tt << 48));
+}
+
+/* time invariant version of gf128mul_x8_lle */
+static void gf128mul_x8_lle_ti(be128 *x)
+{
+ u64 a = be64_to_cpu(x->a);
+ u64 b = be64_to_cpu(x->b);
+ u64 _tt = xda_le(b & 0xff); /* avoid table lookup */
+
+ x->b = cpu_to_be64((b >> 8) | (a << 56));
+ x->a = cpu_to_be64((a >> 8) ^ (_tt << 48));
+}
+
+static void gf128mul_x8_bbe(be128 *x)
+{
+ u64 a = be64_to_cpu(x->a);
+ u64 b = be64_to_cpu(x->b);
+ u64 _tt = gf128mul_table_be[a >> 56];
+
+ x->a = cpu_to_be64((a << 8) | (b >> 56));
+ x->b = cpu_to_be64((b << 8) ^ _tt);
+}
+
+void gf128mul_x8_ble(le128 *r, const le128 *x)
+{
+ u64 a = le64_to_cpu(x->a);
+ u64 b = le64_to_cpu(x->b);
+ u64 _tt = gf128mul_table_be[a >> 56];
+
+ r->a = cpu_to_le64((a << 8) | (b >> 56));
+ r->b = cpu_to_le64((b << 8) ^ _tt);
+}
+EXPORT_SYMBOL(gf128mul_x8_ble);
+
+void gf128mul_lle(be128 *r, const be128 *b)
+{
+ /*
+ * The p array should be aligned to twice the size of its element type,
+ * so that every even/odd pair is guaranteed to share a cacheline
+ * (assuming a cacheline size of 32 bytes or more, which is by far the
+ * most common). This ensures that each be128_xor() call in the loop
+ * takes the same amount of time regardless of the value of 'ch', which
+ * is derived from function parameter 'b', which is commonly used as a
+ * key, e.g., for GHASH. The odd array elements are all set to zero,
+ * making each be128_xor() a NOP if its associated bit in 'ch' is not
+ * set, and this is equivalent to calling be128_xor() conditionally.
+ * This approach aims to avoid leaking information about such keys
+ * through execution time variances.
+ *
+ * Unfortunately, __aligned(16) or higher does not work on x86 for
+ * variables on the stack so we need to perform the alignment by hand.
+ */
+ be128 array[16 + 3] = {};
+ be128 *p = PTR_ALIGN(&array[0], 2 * sizeof(be128));
+ int i;
+
+ p[0] = *r;
+ for (i = 0; i < 7; ++i)
+ gf128mul_x_lle(&p[2 * i + 2], &p[2 * i]);
+
+ memset(r, 0, sizeof(*r));
+ for (i = 0;;) {
+ u8 ch = ((u8 *)b)[15 - i];
+
+ be128_xor(r, r, &p[ 0 + !(ch & 0x80)]);
+ be128_xor(r, r, &p[ 2 + !(ch & 0x40)]);
+ be128_xor(r, r, &p[ 4 + !(ch & 0x20)]);
+ be128_xor(r, r, &p[ 6 + !(ch & 0x10)]);
+ be128_xor(r, r, &p[ 8 + !(ch & 0x08)]);
+ be128_xor(r, r, &p[10 + !(ch & 0x04)]);
+ be128_xor(r, r, &p[12 + !(ch & 0x02)]);
+ be128_xor(r, r, &p[14 + !(ch & 0x01)]);
+
+ if (++i >= 16)
+ break;
+
+ gf128mul_x8_lle_ti(r); /* use the time invariant version */
+ }
+}
+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
+ the buffer's lowest byte, we can construct a table of
+ the 256 16 byte values that result from the 256 values
+ of this byte. This requires 4096 bytes. But we also
+ need tables for each of the 16 higher bytes in the
+ buffer as well, which makes 64 kbytes in total.
+*/
+/* additional explanation
+ * t[0][BYTE] contains g*BYTE
+ * t[1][BYTE] contains g*x^8*BYTE
+ * ..
+ * t[15][BYTE] contains g*x^120*BYTE */
+struct gf128mul_64k *gf128mul_init_64k_bbe(const be128 *g)
+{
+ struct gf128mul_64k *t;
+ int i, j, k;
+
+ t = kzalloc(sizeof(*t), GFP_KERNEL);
+ if (!t)
+ goto out;
+
+ for (i = 0; i < 16; i++) {
+ t->t[i] = kzalloc(sizeof(*t->t[i]), GFP_KERNEL);
+ if (!t->t[i]) {
+ gf128mul_free_64k(t);
+ t = NULL;
+ goto out;
+ }
+ }
+
+ t->t[0]->t[1] = *g;
+ for (j = 1; j <= 64; j <<= 1)
+ gf128mul_x_bbe(&t->t[0]->t[j + j], &t->t[0]->t[j]);
+
+ for (i = 0;;) {
+ for (j = 2; j < 256; j += j)
+ for (k = 1; k < j; ++k)
+ be128_xor(&t->t[i]->t[j + k],
+ &t->t[i]->t[j], &t->t[i]->t[k]);
+
+ if (++i >= 16)
+ break;
+
+ for (j = 128; j > 0; j >>= 1) {
+ t->t[i]->t[j] = t->t[i - 1]->t[j];
+ gf128mul_x8_bbe(&t->t[i]->t[j]);
+ }
+ }
+
+out:
+ return t;
+}
+EXPORT_SYMBOL(gf128mul_init_64k_bbe);
+
+void gf128mul_free_64k(struct gf128mul_64k *t)
+{
+ int i;
+
+ for (i = 0; i < 16; i++)
+ kfree_sensitive(t->t[i]);
+ kfree_sensitive(t);
+}
+EXPORT_SYMBOL(gf128mul_free_64k);
+
+void gf128mul_64k_bbe(be128 *a, const struct gf128mul_64k *t)
+{
+ u8 *ap = (u8 *)a;
+ be128 r[1];
+ int i;
+
+ *r = t->t[0]->t[ap[15]];
+ for (i = 1; i < 16; ++i)
+ be128_xor(r, r, &t->t[i]->t[ap[15 - i]]);
+ *a = *r;
+}
+EXPORT_SYMBOL(gf128mul_64k_bbe);
+
+/* This version uses 4k 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 a
+ single byte, we can construct a table of the 256 16 byte
+ values that result from the 256 values of this byte.
+ This requires 4096 bytes. If we take the highest byte in
+ the buffer and use this table to get the result, we then
+ have to multiply by x^120 to get the final value. For the
+ next highest byte the result has to be multiplied by x^112
+ and so on. But we can do this by accumulating the result
+ in an accumulator starting with the result for the top
+ byte. We repeatedly multiply the accumulator value by
+ x^8 and then add in (i.e. xor) the 16 bytes of the next
+ lower byte in the buffer, stopping when we reach the
+ lowest byte. This requires a 4096 byte table.
+*/
+struct gf128mul_4k *gf128mul_init_4k_lle(const be128 *g)
+{
+ struct gf128mul_4k *t;
+ int j, k;
+
+ t = kzalloc(sizeof(*t), GFP_KERNEL);
+ if (!t)
+ goto out;
+
+ t->t[128] = *g;
+ for (j = 64; j > 0; j >>= 1)
+ gf128mul_x_lle(&t->t[j], &t->t[j+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_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;
+ be128 r[1];
+ int i = 15;
+
+ *r = t->t[ap[15]];
+ while (i--) {
+ gf128mul_x8_lle(r);
+ be128_xor(r, r, &t->t[ap[i]]);
+ }
+ *a = *r;
+}
+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)");