linux-stable/crypto/serpent_generic.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Cryptographic API.
*
* Serpent Cipher Algorithm.
*
* Copyright (C) 2002 Dag Arne Osvik <osvik@ii.uib.no>
*/
#include <crypto/algapi.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <asm/unaligned.h>
#include <linux/types.h>
#include <crypto/serpent.h>
/* Key is padded to the maximum of 256 bits before round key generation.
* Any key length <= 256 bits (32 bytes) is allowed by the algorithm.
*/
#define PHI 0x9e3779b9UL
#define keyiter(a, b, c, d, i, j) \
({ b ^= d; b ^= c; b ^= a; b ^= PHI ^ i; b = rol32(b, 11); k[j] = b; })
#define loadkeys(x0, x1, x2, x3, i) \
({ x0 = k[i]; x1 = k[i+1]; x2 = k[i+2]; x3 = k[i+3]; })
#define storekeys(x0, x1, x2, x3, i) \
({ k[i] = x0; k[i+1] = x1; k[i+2] = x2; k[i+3] = x3; })
#define store_and_load_keys(x0, x1, x2, x3, s, l) \
({ storekeys(x0, x1, x2, x3, s); loadkeys(x0, x1, x2, x3, l); })
#define K(x0, x1, x2, x3, i) ({ \
x3 ^= k[4*(i)+3]; x2 ^= k[4*(i)+2]; \
x1 ^= k[4*(i)+1]; x0 ^= k[4*(i)+0]; \
})
#define LK(x0, x1, x2, x3, x4, i) ({ \
x0 = rol32(x0, 13);\
x2 = rol32(x2, 3); x1 ^= x0; x4 = x0 << 3; \
x3 ^= x2; x1 ^= x2; \
x1 = rol32(x1, 1); x3 ^= x4; \
x3 = rol32(x3, 7); x4 = x1; \
x0 ^= x1; x4 <<= 7; x2 ^= x3; \
x0 ^= x3; x2 ^= x4; x3 ^= k[4*i+3]; \
x1 ^= k[4*i+1]; x0 = rol32(x0, 5); x2 = rol32(x2, 22);\
x0 ^= k[4*i+0]; x2 ^= k[4*i+2]; \
})
#define KL(x0, x1, x2, x3, x4, i) ({ \
x0 ^= k[4*i+0]; x1 ^= k[4*i+1]; x2 ^= k[4*i+2]; \
x3 ^= k[4*i+3]; x0 = ror32(x0, 5); x2 = ror32(x2, 22);\
x4 = x1; x2 ^= x3; x0 ^= x3; \
x4 <<= 7; x0 ^= x1; x1 = ror32(x1, 1); \
x2 ^= x4; x3 = ror32(x3, 7); x4 = x0 << 3; \
x1 ^= x0; x3 ^= x4; x0 = ror32(x0, 13);\
x1 ^= x2; x3 ^= x2; x2 = ror32(x2, 3); \
})
#define S0(x0, x1, x2, x3, x4) ({ \
x4 = x3; \
x3 |= x0; x0 ^= x4; x4 ^= x2; \
x4 = ~x4; x3 ^= x1; x1 &= x0; \
x1 ^= x4; x2 ^= x0; x0 ^= x3; \
x4 |= x0; x0 ^= x2; x2 &= x1; \
x3 ^= x2; x1 = ~x1; x2 ^= x4; \
x1 ^= x2; \
})
#define S1(x0, x1, x2, x3, x4) ({ \
x4 = x1; \
x1 ^= x0; x0 ^= x3; x3 = ~x3; \
x4 &= x1; x0 |= x1; x3 ^= x2; \
x0 ^= x3; x1 ^= x3; x3 ^= x4; \
x1 |= x4; x4 ^= x2; x2 &= x0; \
x2 ^= x1; x1 |= x0; x0 = ~x0; \
x0 ^= x2; x4 ^= x1; \
})
#define S2(x0, x1, x2, x3, x4) ({ \
x3 = ~x3; \
x1 ^= x0; x4 = x0; x0 &= x2; \
x0 ^= x3; x3 |= x4; x2 ^= x1; \
x3 ^= x1; x1 &= x0; x0 ^= x2; \
x2 &= x3; x3 |= x1; x0 = ~x0; \
x3 ^= x0; x4 ^= x0; x0 ^= x2; \
x1 |= x2; \
})
#define S3(x0, x1, x2, x3, x4) ({ \
x4 = x1; \
x1 ^= x3; x3 |= x0; x4 &= x0; \
x0 ^= x2; x2 ^= x1; x1 &= x3; \
x2 ^= x3; x0 |= x4; x4 ^= x3; \
x1 ^= x0; x0 &= x3; x3 &= x4; \
x3 ^= x2; x4 |= x1; x2 &= x1; \
x4 ^= x3; x0 ^= x3; x3 ^= x2; \
})
#define S4(x0, x1, x2, x3, x4) ({ \
x4 = x3; \
x3 &= x0; x0 ^= x4; \
x3 ^= x2; x2 |= x4; x0 ^= x1; \
x4 ^= x3; x2 |= x0; \
x2 ^= x1; x1 &= x0; \
x1 ^= x4; x4 &= x2; x2 ^= x3; \
x4 ^= x0; x3 |= x1; x1 = ~x1; \
x3 ^= x0; \
})
#define S5(x0, x1, x2, x3, x4) ({ \
x4 = x1; x1 |= x0; \
x2 ^= x1; x3 = ~x3; x4 ^= x0; \
x0 ^= x2; x1 &= x4; x4 |= x3; \
x4 ^= x0; x0 &= x3; x1 ^= x3; \
x3 ^= x2; x0 ^= x1; x2 &= x4; \
x1 ^= x2; x2 &= x0; \
x3 ^= x2; \
})
#define S6(x0, x1, x2, x3, x4) ({ \
x4 = x1; \
x3 ^= x0; x1 ^= x2; x2 ^= x0; \
x0 &= x3; x1 |= x3; x4 = ~x4; \
x0 ^= x1; x1 ^= x2; \
x3 ^= x4; x4 ^= x0; x2 &= x0; \
x4 ^= x1; x2 ^= x3; x3 &= x1; \
x3 ^= x0; x1 ^= x2; \
})
#define S7(x0, x1, x2, x3, x4) ({ \
x1 = ~x1; \
x4 = x1; x0 = ~x0; x1 &= x2; \
x1 ^= x3; x3 |= x4; x4 ^= x2; \
x2 ^= x3; x3 ^= x0; x0 |= x1; \
x2 &= x0; x0 ^= x4; x4 ^= x3; \
x3 &= x0; x4 ^= x1; \
x2 ^= x4; x3 ^= x1; x4 |= x0; \
x4 ^= x1; \
})
#define SI0(x0, x1, x2, x3, x4) ({ \
x4 = x3; x1 ^= x0; \
x3 |= x1; x4 ^= x1; x0 = ~x0; \
x2 ^= x3; x3 ^= x0; x0 &= x1; \
x0 ^= x2; x2 &= x3; x3 ^= x4; \
x2 ^= x3; x1 ^= x3; x3 &= x0; \
x1 ^= x0; x0 ^= x2; x4 ^= x3; \
})
#define SI1(x0, x1, x2, x3, x4) ({ \
x1 ^= x3; x4 = x0; \
x0 ^= x2; x2 = ~x2; x4 |= x1; \
x4 ^= x3; x3 &= x1; x1 ^= x2; \
x2 &= x4; x4 ^= x1; x1 |= x3; \
x3 ^= x0; x2 ^= x0; x0 |= x4; \
x2 ^= x4; x1 ^= x0; \
x4 ^= x1; \
})
#define SI2(x0, x1, x2, x3, x4) ({ \
x2 ^= x1; x4 = x3; x3 = ~x3; \
x3 |= x2; x2 ^= x4; x4 ^= x0; \
x3 ^= x1; x1 |= x2; x2 ^= x0; \
x1 ^= x4; x4 |= x3; x2 ^= x3; \
x4 ^= x2; x2 &= x1; \
x2 ^= x3; x3 ^= x4; x4 ^= x0; \
})
#define SI3(x0, x1, x2, x3, x4) ({ \
x2 ^= x1; \
x4 = x1; x1 &= x2; \
x1 ^= x0; x0 |= x4; x4 ^= x3; \
x0 ^= x3; x3 |= x1; x1 ^= x2; \
x1 ^= x3; x0 ^= x2; x2 ^= x3; \
x3 &= x1; x1 ^= x0; x0 &= x2; \
x4 ^= x3; x3 ^= x0; x0 ^= x1; \
})
#define SI4(x0, x1, x2, x3, x4) ({ \
x2 ^= x3; x4 = x0; x0 &= x1; \
x0 ^= x2; x2 |= x3; x4 = ~x4; \
x1 ^= x0; x0 ^= x2; x2 &= x4; \
x2 ^= x0; x0 |= x4; \
x0 ^= x3; x3 &= x2; \
x4 ^= x3; x3 ^= x1; x1 &= x0; \
x4 ^= x1; x0 ^= x3; \
})
#define SI5(x0, x1, x2, x3, x4) ({ \
x4 = x1; x1 |= x2; \
x2 ^= x4; x1 ^= x3; x3 &= x4; \
x2 ^= x3; x3 |= x0; x0 = ~x0; \
x3 ^= x2; x2 |= x0; x4 ^= x1; \
x2 ^= x4; x4 &= x0; x0 ^= x1; \
x1 ^= x3; x0 &= x2; x2 ^= x3; \
x0 ^= x2; x2 ^= x4; x4 ^= x3; \
})
#define SI6(x0, x1, x2, x3, x4) ({ \
x0 ^= x2; \
x4 = x0; x0 &= x3; x2 ^= x3; \
x0 ^= x2; x3 ^= x1; x2 |= x4; \
x2 ^= x3; x3 &= x0; x0 = ~x0; \
x3 ^= x1; x1 &= x2; x4 ^= x0; \
x3 ^= x4; x4 ^= x2; x0 ^= x1; \
x2 ^= x0; \
})
#define SI7(x0, x1, x2, x3, x4) ({ \
x4 = x3; x3 &= x0; x0 ^= x2; \
x2 |= x4; x4 ^= x1; x0 = ~x0; \
x1 |= x3; x4 ^= x0; x0 &= x2; \
x0 ^= x1; x1 &= x2; x3 ^= x2; \
x4 ^= x3; x2 &= x3; x3 |= x0; \
x1 ^= x4; x3 ^= x4; x4 &= x0; \
x4 ^= x2; \
})
/*
* both gcc and clang have misoptimized this function in the past,
* producing horrible object code from spilling temporary variables
* on the stack. Forcing this part out of line avoids that.
*/
static noinline void __serpent_setkey_sbox(u32 r0, u32 r1, u32 r2,
u32 r3, u32 r4, u32 *k)
crypto: serpent - improve __serpent_setkey with UBSAN When UBSAN is enabled, we get a very large stack frame for __serpent_setkey, when the register allocator ends up using more registers than it has, and has to spill temporary values to the stack. The code was originally optimized for in-order x86-32 CPU implementations using older compilers, but it now runs into a highly suboptimal case on all CPU architectures, as seen by this warning: crypto/serpent_generic.c: In function '__serpent_setkey': crypto/serpent_generic.c:436:1: error: the frame size of 2720 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] Disabling -fsanitize=alignment would avoid that warning, presumably the option turns off a optimization step that is required for getting the register allocation right, but there is no easy way to do that on gcc-7 (gcc-8 introduces a function attribute for this). I tried to figure out a way to modify the source code instead, and noticed that the two stages of the setkey() function (keyiter and sbox) each are fine by themselves, but not when combined into one function. Splitting out the entire sbox into a separate function also happens to work fine with all compilers I tried (arm, arm64 and x86). The setkey function uses a strange way to handle offsets into the key array, using both negative and positive index values, as well as adjusting the array pointer back and forth. I have checked that this actually makes no difference to modern compilers, but I left that untouched to make the patch easier to review and to keep the code closer to the reference implementation. Link: https://patchwork.kernel.org/patch/9189575/ Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-07-31 20:43:55 +00:00
{
k += 100;
S3(r3, r4, r0, r1, r2); store_and_load_keys(r1, r2, r4, r3, 28, 24);
S4(r1, r2, r4, r3, r0); store_and_load_keys(r2, r4, r3, r0, 24, 20);
S5(r2, r4, r3, r0, r1); store_and_load_keys(r1, r2, r4, r0, 20, 16);
S6(r1, r2, r4, r0, r3); store_and_load_keys(r4, r3, r2, r0, 16, 12);
S7(r4, r3, r2, r0, r1); store_and_load_keys(r1, r2, r0, r4, 12, 8);
S0(r1, r2, r0, r4, r3); store_and_load_keys(r0, r2, r4, r1, 8, 4);
S1(r0, r2, r4, r1, r3); store_and_load_keys(r3, r4, r1, r0, 4, 0);
S2(r3, r4, r1, r0, r2); store_and_load_keys(r2, r4, r3, r0, 0, -4);
S3(r2, r4, r3, r0, r1); store_and_load_keys(r0, r1, r4, r2, -4, -8);
S4(r0, r1, r4, r2, r3); store_and_load_keys(r1, r4, r2, r3, -8, -12);
S5(r1, r4, r2, r3, r0); store_and_load_keys(r0, r1, r4, r3, -12, -16);
S6(r0, r1, r4, r3, r2); store_and_load_keys(r4, r2, r1, r3, -16, -20);
S7(r4, r2, r1, r3, r0); store_and_load_keys(r0, r1, r3, r4, -20, -24);
S0(r0, r1, r3, r4, r2); store_and_load_keys(r3, r1, r4, r0, -24, -28);
k -= 50;
S1(r3, r1, r4, r0, r2); store_and_load_keys(r2, r4, r0, r3, 22, 18);
S2(r2, r4, r0, r3, r1); store_and_load_keys(r1, r4, r2, r3, 18, 14);
S3(r1, r4, r2, r3, r0); store_and_load_keys(r3, r0, r4, r1, 14, 10);
S4(r3, r0, r4, r1, r2); store_and_load_keys(r0, r4, r1, r2, 10, 6);
S5(r0, r4, r1, r2, r3); store_and_load_keys(r3, r0, r4, r2, 6, 2);
S6(r3, r0, r4, r2, r1); store_and_load_keys(r4, r1, r0, r2, 2, -2);
S7(r4, r1, r0, r2, r3); store_and_load_keys(r3, r0, r2, r4, -2, -6);
S0(r3, r0, r2, r4, r1); store_and_load_keys(r2, r0, r4, r3, -6, -10);
S1(r2, r0, r4, r3, r1); store_and_load_keys(r1, r4, r3, r2, -10, -14);
S2(r1, r4, r3, r2, r0); store_and_load_keys(r0, r4, r1, r2, -14, -18);
S3(r0, r4, r1, r2, r3); store_and_load_keys(r2, r3, r4, r0, -18, -22);
k -= 50;
S4(r2, r3, r4, r0, r1); store_and_load_keys(r3, r4, r0, r1, 28, 24);
S5(r3, r4, r0, r1, r2); store_and_load_keys(r2, r3, r4, r1, 24, 20);
S6(r2, r3, r4, r1, r0); store_and_load_keys(r4, r0, r3, r1, 20, 16);
S7(r4, r0, r3, r1, r2); store_and_load_keys(r2, r3, r1, r4, 16, 12);
S0(r2, r3, r1, r4, r0); store_and_load_keys(r1, r3, r4, r2, 12, 8);
S1(r1, r3, r4, r2, r0); store_and_load_keys(r0, r4, r2, r1, 8, 4);
S2(r0, r4, r2, r1, r3); store_and_load_keys(r3, r4, r0, r1, 4, 0);
S3(r3, r4, r0, r1, r2); storekeys(r1, r2, r4, r3, 0);
}
int __serpent_setkey(struct serpent_ctx *ctx, const u8 *key,
unsigned int keylen)
{
u32 *k = ctx->expkey;
u8 *k8 = (u8 *)k;
u32 r0, r1, r2, r3, r4;
__le32 *lk;
int i;
/* Copy key, add padding */
for (i = 0; i < keylen; ++i)
k8[i] = key[i];
if (i < SERPENT_MAX_KEY_SIZE)
k8[i++] = 1;
while (i < SERPENT_MAX_KEY_SIZE)
k8[i++] = 0;
lk = (__le32 *)k;
k[0] = le32_to_cpu(lk[0]);
k[1] = le32_to_cpu(lk[1]);
k[2] = le32_to_cpu(lk[2]);
k[3] = le32_to_cpu(lk[3]);
k[4] = le32_to_cpu(lk[4]);
k[5] = le32_to_cpu(lk[5]);
k[6] = le32_to_cpu(lk[6]);
k[7] = le32_to_cpu(lk[7]);
/* Expand key using polynomial */
r0 = k[3];
r1 = k[4];
r2 = k[5];
r3 = k[6];
r4 = k[7];
keyiter(k[0], r0, r4, r2, 0, 0);
keyiter(k[1], r1, r0, r3, 1, 1);
keyiter(k[2], r2, r1, r4, 2, 2);
keyiter(k[3], r3, r2, r0, 3, 3);
keyiter(k[4], r4, r3, r1, 4, 4);
keyiter(k[5], r0, r4, r2, 5, 5);
keyiter(k[6], r1, r0, r3, 6, 6);
keyiter(k[7], r2, r1, r4, 7, 7);
keyiter(k[0], r3, r2, r0, 8, 8);
keyiter(k[1], r4, r3, r1, 9, 9);
keyiter(k[2], r0, r4, r2, 10, 10);
keyiter(k[3], r1, r0, r3, 11, 11);
keyiter(k[4], r2, r1, r4, 12, 12);
keyiter(k[5], r3, r2, r0, 13, 13);
keyiter(k[6], r4, r3, r1, 14, 14);
keyiter(k[7], r0, r4, r2, 15, 15);
keyiter(k[8], r1, r0, r3, 16, 16);
keyiter(k[9], r2, r1, r4, 17, 17);
keyiter(k[10], r3, r2, r0, 18, 18);
keyiter(k[11], r4, r3, r1, 19, 19);
keyiter(k[12], r0, r4, r2, 20, 20);
keyiter(k[13], r1, r0, r3, 21, 21);
keyiter(k[14], r2, r1, r4, 22, 22);
keyiter(k[15], r3, r2, r0, 23, 23);
keyiter(k[16], r4, r3, r1, 24, 24);
keyiter(k[17], r0, r4, r2, 25, 25);
keyiter(k[18], r1, r0, r3, 26, 26);
keyiter(k[19], r2, r1, r4, 27, 27);
keyiter(k[20], r3, r2, r0, 28, 28);
keyiter(k[21], r4, r3, r1, 29, 29);
keyiter(k[22], r0, r4, r2, 30, 30);
keyiter(k[23], r1, r0, r3, 31, 31);
k += 50;
keyiter(k[-26], r2, r1, r4, 32, -18);
keyiter(k[-25], r3, r2, r0, 33, -17);
keyiter(k[-24], r4, r3, r1, 34, -16);
keyiter(k[-23], r0, r4, r2, 35, -15);
keyiter(k[-22], r1, r0, r3, 36, -14);
keyiter(k[-21], r2, r1, r4, 37, -13);
keyiter(k[-20], r3, r2, r0, 38, -12);
keyiter(k[-19], r4, r3, r1, 39, -11);
keyiter(k[-18], r0, r4, r2, 40, -10);
keyiter(k[-17], r1, r0, r3, 41, -9);
keyiter(k[-16], r2, r1, r4, 42, -8);
keyiter(k[-15], r3, r2, r0, 43, -7);
keyiter(k[-14], r4, r3, r1, 44, -6);
keyiter(k[-13], r0, r4, r2, 45, -5);
keyiter(k[-12], r1, r0, r3, 46, -4);
keyiter(k[-11], r2, r1, r4, 47, -3);
keyiter(k[-10], r3, r2, r0, 48, -2);
keyiter(k[-9], r4, r3, r1, 49, -1);
keyiter(k[-8], r0, r4, r2, 50, 0);
keyiter(k[-7], r1, r0, r3, 51, 1);
keyiter(k[-6], r2, r1, r4, 52, 2);
keyiter(k[-5], r3, r2, r0, 53, 3);
keyiter(k[-4], r4, r3, r1, 54, 4);
keyiter(k[-3], r0, r4, r2, 55, 5);
keyiter(k[-2], r1, r0, r3, 56, 6);
keyiter(k[-1], r2, r1, r4, 57, 7);
keyiter(k[0], r3, r2, r0, 58, 8);
keyiter(k[1], r4, r3, r1, 59, 9);
keyiter(k[2], r0, r4, r2, 60, 10);
keyiter(k[3], r1, r0, r3, 61, 11);
keyiter(k[4], r2, r1, r4, 62, 12);
keyiter(k[5], r3, r2, r0, 63, 13);
keyiter(k[6], r4, r3, r1, 64, 14);
keyiter(k[7], r0, r4, r2, 65, 15);
keyiter(k[8], r1, r0, r3, 66, 16);
keyiter(k[9], r2, r1, r4, 67, 17);
keyiter(k[10], r3, r2, r0, 68, 18);
keyiter(k[11], r4, r3, r1, 69, 19);
keyiter(k[12], r0, r4, r2, 70, 20);
keyiter(k[13], r1, r0, r3, 71, 21);
keyiter(k[14], r2, r1, r4, 72, 22);
keyiter(k[15], r3, r2, r0, 73, 23);
keyiter(k[16], r4, r3, r1, 74, 24);
keyiter(k[17], r0, r4, r2, 75, 25);
keyiter(k[18], r1, r0, r3, 76, 26);
keyiter(k[19], r2, r1, r4, 77, 27);
keyiter(k[20], r3, r2, r0, 78, 28);
keyiter(k[21], r4, r3, r1, 79, 29);
keyiter(k[22], r0, r4, r2, 80, 30);
keyiter(k[23], r1, r0, r3, 81, 31);
k += 50;
keyiter(k[-26], r2, r1, r4, 82, -18);
keyiter(k[-25], r3, r2, r0, 83, -17);
keyiter(k[-24], r4, r3, r1, 84, -16);
keyiter(k[-23], r0, r4, r2, 85, -15);
keyiter(k[-22], r1, r0, r3, 86, -14);
keyiter(k[-21], r2, r1, r4, 87, -13);
keyiter(k[-20], r3, r2, r0, 88, -12);
keyiter(k[-19], r4, r3, r1, 89, -11);
keyiter(k[-18], r0, r4, r2, 90, -10);
keyiter(k[-17], r1, r0, r3, 91, -9);
keyiter(k[-16], r2, r1, r4, 92, -8);
keyiter(k[-15], r3, r2, r0, 93, -7);
keyiter(k[-14], r4, r3, r1, 94, -6);
keyiter(k[-13], r0, r4, r2, 95, -5);
keyiter(k[-12], r1, r0, r3, 96, -4);
keyiter(k[-11], r2, r1, r4, 97, -3);
keyiter(k[-10], r3, r2, r0, 98, -2);
keyiter(k[-9], r4, r3, r1, 99, -1);
keyiter(k[-8], r0, r4, r2, 100, 0);
keyiter(k[-7], r1, r0, r3, 101, 1);
keyiter(k[-6], r2, r1, r4, 102, 2);
keyiter(k[-5], r3, r2, r0, 103, 3);
keyiter(k[-4], r4, r3, r1, 104, 4);
keyiter(k[-3], r0, r4, r2, 105, 5);
keyiter(k[-2], r1, r0, r3, 106, 6);
keyiter(k[-1], r2, r1, r4, 107, 7);
keyiter(k[0], r3, r2, r0, 108, 8);
keyiter(k[1], r4, r3, r1, 109, 9);
keyiter(k[2], r0, r4, r2, 110, 10);
keyiter(k[3], r1, r0, r3, 111, 11);
keyiter(k[4], r2, r1, r4, 112, 12);
keyiter(k[5], r3, r2, r0, 113, 13);
keyiter(k[6], r4, r3, r1, 114, 14);
keyiter(k[7], r0, r4, r2, 115, 15);
keyiter(k[8], r1, r0, r3, 116, 16);
keyiter(k[9], r2, r1, r4, 117, 17);
keyiter(k[10], r3, r2, r0, 118, 18);
keyiter(k[11], r4, r3, r1, 119, 19);
keyiter(k[12], r0, r4, r2, 120, 20);
keyiter(k[13], r1, r0, r3, 121, 21);
keyiter(k[14], r2, r1, r4, 122, 22);
keyiter(k[15], r3, r2, r0, 123, 23);
keyiter(k[16], r4, r3, r1, 124, 24);
keyiter(k[17], r0, r4, r2, 125, 25);
keyiter(k[18], r1, r0, r3, 126, 26);
keyiter(k[19], r2, r1, r4, 127, 27);
keyiter(k[20], r3, r2, r0, 128, 28);
keyiter(k[21], r4, r3, r1, 129, 29);
keyiter(k[22], r0, r4, r2, 130, 30);
keyiter(k[23], r1, r0, r3, 131, 31);
/* Apply S-boxes */
crypto: serpent - improve __serpent_setkey with UBSAN When UBSAN is enabled, we get a very large stack frame for __serpent_setkey, when the register allocator ends up using more registers than it has, and has to spill temporary values to the stack. The code was originally optimized for in-order x86-32 CPU implementations using older compilers, but it now runs into a highly suboptimal case on all CPU architectures, as seen by this warning: crypto/serpent_generic.c: In function '__serpent_setkey': crypto/serpent_generic.c:436:1: error: the frame size of 2720 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] Disabling -fsanitize=alignment would avoid that warning, presumably the option turns off a optimization step that is required for getting the register allocation right, but there is no easy way to do that on gcc-7 (gcc-8 introduces a function attribute for this). I tried to figure out a way to modify the source code instead, and noticed that the two stages of the setkey() function (keyiter and sbox) each are fine by themselves, but not when combined into one function. Splitting out the entire sbox into a separate function also happens to work fine with all compilers I tried (arm, arm64 and x86). The setkey function uses a strange way to handle offsets into the key array, using both negative and positive index values, as well as adjusting the array pointer back and forth. I have checked that this actually makes no difference to modern compilers, but I left that untouched to make the patch easier to review and to keep the code closer to the reference implementation. Link: https://patchwork.kernel.org/patch/9189575/ Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-07-31 20:43:55 +00:00
__serpent_setkey_sbox(r0, r1, r2, r3, r4, ctx->expkey);
return 0;
}
EXPORT_SYMBOL_GPL(__serpent_setkey);
int serpent_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
{
return __serpent_setkey(crypto_tfm_ctx(tfm), key, keylen);
}
EXPORT_SYMBOL_GPL(serpent_setkey);
void __serpent_encrypt(const void *c, u8 *dst, const u8 *src)
{
const struct serpent_ctx *ctx = c;
const u32 *k = ctx->expkey;
u32 r0, r1, r2, r3, r4;
r0 = get_unaligned_le32(src);
r1 = get_unaligned_le32(src + 4);
r2 = get_unaligned_le32(src + 8);
r3 = get_unaligned_le32(src + 12);
K(r0, r1, r2, r3, 0);
S0(r0, r1, r2, r3, r4); LK(r2, r1, r3, r0, r4, 1);
S1(r2, r1, r3, r0, r4); LK(r4, r3, r0, r2, r1, 2);
S2(r4, r3, r0, r2, r1); LK(r1, r3, r4, r2, r0, 3);
S3(r1, r3, r4, r2, r0); LK(r2, r0, r3, r1, r4, 4);
S4(r2, r0, r3, r1, r4); LK(r0, r3, r1, r4, r2, 5);
S5(r0, r3, r1, r4, r2); LK(r2, r0, r3, r4, r1, 6);
S6(r2, r0, r3, r4, r1); LK(r3, r1, r0, r4, r2, 7);
S7(r3, r1, r0, r4, r2); LK(r2, r0, r4, r3, r1, 8);
S0(r2, r0, r4, r3, r1); LK(r4, r0, r3, r2, r1, 9);
S1(r4, r0, r3, r2, r1); LK(r1, r3, r2, r4, r0, 10);
S2(r1, r3, r2, r4, r0); LK(r0, r3, r1, r4, r2, 11);
S3(r0, r3, r1, r4, r2); LK(r4, r2, r3, r0, r1, 12);
S4(r4, r2, r3, r0, r1); LK(r2, r3, r0, r1, r4, 13);
S5(r2, r3, r0, r1, r4); LK(r4, r2, r3, r1, r0, 14);
S6(r4, r2, r3, r1, r0); LK(r3, r0, r2, r1, r4, 15);
S7(r3, r0, r2, r1, r4); LK(r4, r2, r1, r3, r0, 16);
S0(r4, r2, r1, r3, r0); LK(r1, r2, r3, r4, r0, 17);
S1(r1, r2, r3, r4, r0); LK(r0, r3, r4, r1, r2, 18);
S2(r0, r3, r4, r1, r2); LK(r2, r3, r0, r1, r4, 19);
S3(r2, r3, r0, r1, r4); LK(r1, r4, r3, r2, r0, 20);
S4(r1, r4, r3, r2, r0); LK(r4, r3, r2, r0, r1, 21);
S5(r4, r3, r2, r0, r1); LK(r1, r4, r3, r0, r2, 22);
S6(r1, r4, r3, r0, r2); LK(r3, r2, r4, r0, r1, 23);
S7(r3, r2, r4, r0, r1); LK(r1, r4, r0, r3, r2, 24);
S0(r1, r4, r0, r3, r2); LK(r0, r4, r3, r1, r2, 25);
S1(r0, r4, r3, r1, r2); LK(r2, r3, r1, r0, r4, 26);
S2(r2, r3, r1, r0, r4); LK(r4, r3, r2, r0, r1, 27);
S3(r4, r3, r2, r0, r1); LK(r0, r1, r3, r4, r2, 28);
S4(r0, r1, r3, r4, r2); LK(r1, r3, r4, r2, r0, 29);
S5(r1, r3, r4, r2, r0); LK(r0, r1, r3, r2, r4, 30);
S6(r0, r1, r3, r2, r4); LK(r3, r4, r1, r2, r0, 31);
S7(r3, r4, r1, r2, r0); K(r0, r1, r2, r3, 32);
put_unaligned_le32(r0, dst);
put_unaligned_le32(r1, dst + 4);
put_unaligned_le32(r2, dst + 8);
put_unaligned_le32(r3, dst + 12);
}
EXPORT_SYMBOL_GPL(__serpent_encrypt);
static void serpent_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
struct serpent_ctx *ctx = crypto_tfm_ctx(tfm);
__serpent_encrypt(ctx, dst, src);
}
void __serpent_decrypt(const void *c, u8 *dst, const u8 *src)
{
const struct serpent_ctx *ctx = c;
const u32 *k = ctx->expkey;
u32 r0, r1, r2, r3, r4;
r0 = get_unaligned_le32(src);
r1 = get_unaligned_le32(src + 4);
r2 = get_unaligned_le32(src + 8);
r3 = get_unaligned_le32(src + 12);
K(r0, r1, r2, r3, 32);
SI7(r0, r1, r2, r3, r4); KL(r1, r3, r0, r4, r2, 31);
SI6(r1, r3, r0, r4, r2); KL(r0, r2, r4, r1, r3, 30);
SI5(r0, r2, r4, r1, r3); KL(r2, r3, r0, r4, r1, 29);
SI4(r2, r3, r0, r4, r1); KL(r2, r0, r1, r4, r3, 28);
SI3(r2, r0, r1, r4, r3); KL(r1, r2, r3, r4, r0, 27);
SI2(r1, r2, r3, r4, r0); KL(r2, r0, r4, r3, r1, 26);
SI1(r2, r0, r4, r3, r1); KL(r1, r0, r4, r3, r2, 25);
SI0(r1, r0, r4, r3, r2); KL(r4, r2, r0, r1, r3, 24);
SI7(r4, r2, r0, r1, r3); KL(r2, r1, r4, r3, r0, 23);
SI6(r2, r1, r4, r3, r0); KL(r4, r0, r3, r2, r1, 22);
SI5(r4, r0, r3, r2, r1); KL(r0, r1, r4, r3, r2, 21);
SI4(r0, r1, r4, r3, r2); KL(r0, r4, r2, r3, r1, 20);
SI3(r0, r4, r2, r3, r1); KL(r2, r0, r1, r3, r4, 19);
SI2(r2, r0, r1, r3, r4); KL(r0, r4, r3, r1, r2, 18);
SI1(r0, r4, r3, r1, r2); KL(r2, r4, r3, r1, r0, 17);
SI0(r2, r4, r3, r1, r0); KL(r3, r0, r4, r2, r1, 16);
SI7(r3, r0, r4, r2, r1); KL(r0, r2, r3, r1, r4, 15);
SI6(r0, r2, r3, r1, r4); KL(r3, r4, r1, r0, r2, 14);
SI5(r3, r4, r1, r0, r2); KL(r4, r2, r3, r1, r0, 13);
SI4(r4, r2, r3, r1, r0); KL(r4, r3, r0, r1, r2, 12);
SI3(r4, r3, r0, r1, r2); KL(r0, r4, r2, r1, r3, 11);
SI2(r0, r4, r2, r1, r3); KL(r4, r3, r1, r2, r0, 10);
SI1(r4, r3, r1, r2, r0); KL(r0, r3, r1, r2, r4, 9);
SI0(r0, r3, r1, r2, r4); KL(r1, r4, r3, r0, r2, 8);
SI7(r1, r4, r3, r0, r2); KL(r4, r0, r1, r2, r3, 7);
SI6(r4, r0, r1, r2, r3); KL(r1, r3, r2, r4, r0, 6);
SI5(r1, r3, r2, r4, r0); KL(r3, r0, r1, r2, r4, 5);
SI4(r3, r0, r1, r2, r4); KL(r3, r1, r4, r2, r0, 4);
SI3(r3, r1, r4, r2, r0); KL(r4, r3, r0, r2, r1, 3);
SI2(r4, r3, r0, r2, r1); KL(r3, r1, r2, r0, r4, 2);
SI1(r3, r1, r2, r0, r4); KL(r4, r1, r2, r0, r3, 1);
SI0(r4, r1, r2, r0, r3); K(r2, r3, r1, r4, 0);
put_unaligned_le32(r2, dst);
put_unaligned_le32(r3, dst + 4);
put_unaligned_le32(r1, dst + 8);
put_unaligned_le32(r4, dst + 12);
}
EXPORT_SYMBOL_GPL(__serpent_decrypt);
static void serpent_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
struct serpent_ctx *ctx = crypto_tfm_ctx(tfm);
__serpent_decrypt(ctx, dst, src);
}
static struct crypto_alg srp_alg = {
.cra_name = "serpent",
.cra_driver_name = "serpent-generic",
.cra_priority = 100,
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
.cra_blocksize = SERPENT_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct serpent_ctx),
.cra_module = THIS_MODULE,
.cra_u = { .cipher = {
.cia_min_keysize = SERPENT_MIN_KEY_SIZE,
.cia_max_keysize = SERPENT_MAX_KEY_SIZE,
.cia_setkey = serpent_setkey,
.cia_encrypt = serpent_encrypt,
.cia_decrypt = serpent_decrypt } }
};
static int __init serpent_mod_init(void)
{
return crypto_register_alg(&srp_alg);
}
static void __exit serpent_mod_fini(void)
{
crypto_unregister_alg(&srp_alg);
}
subsys_initcall(serpent_mod_init);
module_exit(serpent_mod_fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Serpent Cipher Algorithm");
MODULE_AUTHOR("Dag Arne Osvik <osvik@ii.uib.no>");
MODULE_ALIAS_CRYPTO("serpent");
MODULE_ALIAS_CRYPTO("serpent-generic");