Revision 8ec7791bae1327b1c279c5cd6e929c3b12daaf0a authored by Michael Ellerman on 06 May 2021, 04:49:58 UTC, committed by Michael Ellerman on 14 May 2021, 07:27:36 UTC
The STF (store-to-load forwarding) barrier mitigation can be
enabled/disabled at runtime via a debugfs file (stf_barrier), which
causes the kernel to patch itself to enable/disable the relevant
mitigations.

However depending on which mitigation we're using, it may not be safe to
do that patching while other CPUs are active. For example the following
crash:

  User access of kernel address (c00000003fff5af0) - exploit attempt? (uid: 0)
  segfault (11) at c00000003fff5af0 nip 7fff8ad12198 lr 7fff8ad121f8 code 1
  code: 40820128 e93c00d0 e9290058 7c292840 40810058 38600000 4bfd9a81 e8410018
  code: 2c030006 41810154 3860ffb6 e9210098 <e94d8ff0> 7d295279 39400000 40820a3c

Shows that we returned to userspace without restoring the user r13
value, due to executing the partially patched STF exit code.

Fix it by doing the patching under stop machine. The CPUs that aren't
doing the patching will be spinning in the core of the stop machine
logic. That is currently sufficient for our purposes, because none of
the patching we do is to that code or anywhere in the vicinity.

Fixes: a048a07d7f45 ("powerpc/64s: Add support for a store forwarding barrier at kernel entry/exit")
Cc: stable@vger.kernel.org # v4.17+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210506044959.1298123-1-mpe@ellerman.id.au

1 parent da3bb20
Raw File
serpent_generic.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Cryptographic API.
 *
 * Serpent Cipher Algorithm.
 *
 * Copyright (C) 2002 Dag Arne Osvik <osvik@ii.uib.no>
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <asm/unaligned.h>
#include <linux/crypto.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)
{
	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 */
	__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");
back to top