diff options
Diffstat (limited to 'lib/crypto')
| -rw-r--r-- | lib/crypto/Kconfig | 7 | ||||
| -rw-r--r-- | lib/crypto/Makefile | 3 | ||||
| -rw-r--r-- | lib/crypto/memneq.c | 173 | ||||
| -rw-r--r-- | lib/crypto/utils.c | 88 |
4 files changed, 269 insertions, 2 deletions
diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig index 47816af9a9d7..7e9683e9f5c6 100644 --- a/lib/crypto/Kconfig +++ b/lib/crypto/Kconfig @@ -2,6 +2,9 @@ menu "Crypto library routines" +config CRYPTO_LIB_UTILS + tristate + config CRYPTO_LIB_AES tristate @@ -33,6 +36,7 @@ config CRYPTO_ARCH_HAVE_LIB_CHACHA config CRYPTO_LIB_CHACHA_GENERIC tristate + select CRYPTO_LIB_UTILS help This symbol can be depended upon by arch implementations of the ChaCha library interface that require the generic code as a @@ -42,7 +46,6 @@ config CRYPTO_LIB_CHACHA_GENERIC config CRYPTO_LIB_CHACHA tristate "ChaCha library interface" - depends on CRYPTO depends on CRYPTO_ARCH_HAVE_LIB_CHACHA || !CRYPTO_ARCH_HAVE_LIB_CHACHA select CRYPTO_LIB_CHACHA_GENERIC if CRYPTO_ARCH_HAVE_LIB_CHACHA=n help @@ -70,7 +73,7 @@ config CRYPTO_LIB_CURVE25519 tristate "Curve25519 scalar multiplication library" depends on CRYPTO_ARCH_HAVE_LIB_CURVE25519 || !CRYPTO_ARCH_HAVE_LIB_CURVE25519 select CRYPTO_LIB_CURVE25519_GENERIC if CRYPTO_ARCH_HAVE_LIB_CURVE25519=n - select LIB_MEMNEQ + select CRYPTO_LIB_UTILS help Enable the Curve25519 library interface. This interface may be fulfilled by either the generic implementation or an arch-specific diff --git a/lib/crypto/Makefile b/lib/crypto/Makefile index 919cbb2c220d..c852f067ab06 100644 --- a/lib/crypto/Makefile +++ b/lib/crypto/Makefile @@ -1,5 +1,8 @@ # SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_CRYPTO_LIB_UTILS) += libcryptoutils.o +libcryptoutils-y := memneq.o utils.o + # chacha is used by the /dev/random driver which is always builtin obj-y += chacha.o obj-$(CONFIG_CRYPTO_LIB_CHACHA_GENERIC) += libchacha.o diff --git a/lib/crypto/memneq.c b/lib/crypto/memneq.c new file mode 100644 index 000000000000..243d8677cc51 --- /dev/null +++ b/lib/crypto/memneq.c @@ -0,0 +1,173 @@ +/* + * Constant-time equality testing of memory regions. + * + * Authors: + * + * James Yonan <james@openvpn.net> + * Daniel Borkmann <dborkman@redhat.com> + * + * This file is provided under a dual BSD/GPLv2 license. When using or + * redistributing this file, you may do so under either license. + * + * GPL LICENSE SUMMARY + * + * Copyright(c) 2013 OpenVPN Technologies, Inc. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. + * The full GNU General Public License is included in this distribution + * in the file called LICENSE.GPL. + * + * BSD LICENSE + * + * Copyright(c) 2013 OpenVPN Technologies, Inc. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * * Neither the name of OpenVPN Technologies nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <asm/unaligned.h> +#include <crypto/algapi.h> +#include <linux/module.h> + +/* Generic path for arbitrary size */ +static inline unsigned long +__crypto_memneq_generic(const void *a, const void *b, size_t size) +{ + unsigned long neq = 0; + +#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) + while (size >= sizeof(unsigned long)) { + neq |= get_unaligned((unsigned long *)a) ^ + get_unaligned((unsigned long *)b); + OPTIMIZER_HIDE_VAR(neq); + a += sizeof(unsigned long); + b += sizeof(unsigned long); + size -= sizeof(unsigned long); + } +#endif /* CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS */ + while (size > 0) { + neq |= *(unsigned char *)a ^ *(unsigned char *)b; + OPTIMIZER_HIDE_VAR(neq); + a += 1; + b += 1; + size -= 1; + } + return neq; +} + +/* Loop-free fast-path for frequently used 16-byte size */ +static inline unsigned long __crypto_memneq_16(const void *a, const void *b) +{ + unsigned long neq = 0; + +#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS + if (sizeof(unsigned long) == 8) { + neq |= get_unaligned((unsigned long *)a) ^ + get_unaligned((unsigned long *)b); + OPTIMIZER_HIDE_VAR(neq); + neq |= get_unaligned((unsigned long *)(a + 8)) ^ + get_unaligned((unsigned long *)(b + 8)); + OPTIMIZER_HIDE_VAR(neq); + } else if (sizeof(unsigned int) == 4) { + neq |= get_unaligned((unsigned int *)a) ^ + get_unaligned((unsigned int *)b); + OPTIMIZER_HIDE_VAR(neq); + neq |= get_unaligned((unsigned int *)(a + 4)) ^ + get_unaligned((unsigned int *)(b + 4)); + OPTIMIZER_HIDE_VAR(neq); + neq |= get_unaligned((unsigned int *)(a + 8)) ^ + get_unaligned((unsigned int *)(b + 8)); + OPTIMIZER_HIDE_VAR(neq); + neq |= get_unaligned((unsigned int *)(a + 12)) ^ + get_unaligned((unsigned int *)(b + 12)); + OPTIMIZER_HIDE_VAR(neq); + } else +#endif /* CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS */ + { + neq |= *(unsigned char *)(a) ^ *(unsigned char *)(b); + OPTIMIZER_HIDE_VAR(neq); + neq |= *(unsigned char *)(a+1) ^ *(unsigned char *)(b+1); + OPTIMIZER_HIDE_VAR(neq); + neq |= *(unsigned char *)(a+2) ^ *(unsigned char *)(b+2); + OPTIMIZER_HIDE_VAR(neq); + neq |= *(unsigned char *)(a+3) ^ *(unsigned char *)(b+3); + OPTIMIZER_HIDE_VAR(neq); + neq |= *(unsigned char *)(a+4) ^ *(unsigned char *)(b+4); + OPTIMIZER_HIDE_VAR(neq); + neq |= *(unsigned char *)(a+5) ^ *(unsigned char *)(b+5); + OPTIMIZER_HIDE_VAR(neq); + neq |= *(unsigned char *)(a+6) ^ *(unsigned char *)(b+6); + OPTIMIZER_HIDE_VAR(neq); + neq |= *(unsigned char *)(a+7) ^ *(unsigned char *)(b+7); + OPTIMIZER_HIDE_VAR(neq); + neq |= *(unsigned char *)(a+8) ^ *(unsigned char *)(b+8); + OPTIMIZER_HIDE_VAR(neq); + neq |= *(unsigned char *)(a+9) ^ *(unsigned char *)(b+9); + OPTIMIZER_HIDE_VAR(neq); + neq |= *(unsigned char *)(a+10) ^ *(unsigned char *)(b+10); + OPTIMIZER_HIDE_VAR(neq); + neq |= *(unsigned char *)(a+11) ^ *(unsigned char *)(b+11); + OPTIMIZER_HIDE_VAR(neq); + neq |= *(unsigned char *)(a+12) ^ *(unsigned char *)(b+12); + OPTIMIZER_HIDE_VAR(neq); + neq |= *(unsigned char *)(a+13) ^ *(unsigned char *)(b+13); + OPTIMIZER_HIDE_VAR(neq); + neq |= *(unsigned char *)(a+14) ^ *(unsigned char *)(b+14); + OPTIMIZER_HIDE_VAR(neq); + neq |= *(unsigned char *)(a+15) ^ *(unsigned char *)(b+15); + OPTIMIZER_HIDE_VAR(neq); + } + + return neq; +} + +/* Compare two areas of memory without leaking timing information, + * and with special optimizations for common sizes. Users should + * not call this function directly, but should instead use + * crypto_memneq defined in crypto/algapi.h. + */ +noinline unsigned long __crypto_memneq(const void *a, const void *b, + size_t size) +{ + switch (size) { + case 16: + return __crypto_memneq_16(a, b); + default: + return __crypto_memneq_generic(a, b, size); + } +} +EXPORT_SYMBOL(__crypto_memneq); diff --git a/lib/crypto/utils.c b/lib/crypto/utils.c new file mode 100644 index 000000000000..53230ab1b195 --- /dev/null +++ b/lib/crypto/utils.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Crypto library utility functions + * + * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au> + */ + +#include <asm/unaligned.h> +#include <crypto/algapi.h> +#include <linux/module.h> + +/* + * XOR @len bytes from @src1 and @src2 together, writing the result to @dst + * (which may alias one of the sources). Don't call this directly; call + * crypto_xor() or crypto_xor_cpy() instead. + */ +void __crypto_xor(u8 *dst, const u8 *src1, const u8 *src2, unsigned int len) +{ + int relalign = 0; + + if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) { + int size = sizeof(unsigned long); + int d = (((unsigned long)dst ^ (unsigned long)src1) | + ((unsigned long)dst ^ (unsigned long)src2)) & + (size - 1); + + relalign = d ? 1 << __ffs(d) : size; + + /* + * If we care about alignment, process as many bytes as + * needed to advance dst and src to values whose alignments + * equal their relative alignment. This will allow us to + * process the remainder of the input using optimal strides. + */ + while (((unsigned long)dst & (relalign - 1)) && len > 0) { + *dst++ = *src1++ ^ *src2++; + len--; + } + } + + while (IS_ENABLED(CONFIG_64BIT) && len >= 8 && !(relalign & 7)) { + if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) { + u64 l = get_unaligned((u64 *)src1) ^ + get_unaligned((u64 *)src2); + put_unaligned(l, (u64 *)dst); + } else { + *(u64 *)dst = *(u64 *)src1 ^ *(u64 *)src2; + } + dst += 8; + src1 += 8; + src2 += 8; + len -= 8; + } + + while (len >= 4 && !(relalign & 3)) { + if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) { + u32 l = get_unaligned((u32 *)src1) ^ + get_unaligned((u32 *)src2); + put_unaligned(l, (u32 *)dst); + } else { + *(u32 *)dst = *(u32 *)src1 ^ *(u32 *)src2; + } + dst += 4; + src1 += 4; + src2 += 4; + len -= 4; + } + + while (len >= 2 && !(relalign & 1)) { + if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) { + u16 l = get_unaligned((u16 *)src1) ^ + get_unaligned((u16 *)src2); + put_unaligned(l, (u16 *)dst); + } else { + *(u16 *)dst = *(u16 *)src1 ^ *(u16 *)src2; + } + dst += 2; + src1 += 2; + src2 += 2; + len -= 2; + } + + while (len--) + *dst++ = *src1++ ^ *src2++; +} +EXPORT_SYMBOL_GPL(__crypto_xor); + +MODULE_LICENSE("GPL"); |