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/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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 AUTHOR 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.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
/* ====================================================================
* Copyright (c) 1998-2001 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. 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.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* openssl-core@openssl.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED 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 OpenSSL PROJECT OR
* ITS 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.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com). */
#ifndef OPENSSL_HEADER_CRYPTO_INTERNAL_H
#define OPENSSL_HEADER_CRYPTO_INTERNAL_H
#include <GFp/base.h> // Must be first.
#include "GFp/check.h"
#if defined(__GNUC__) && \
(__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) < 40800
// |alignas| and |alignof| were added in C11. GCC added support in version 4.8.
// Testing for __STDC_VERSION__/__cplusplus doesn't work because 4.7 already
// reports support for C11.
#define alignas(x) __attribute__ ((aligned (x)))
#elif defined(_MSC_VER) && !defined(__clang__)
#define alignas(x) __declspec(align(x))
#else
#include <stdalign.h>
#endif
#if (!defined(_MSC_VER) || defined(__clang__)) && defined(OPENSSL_64_BIT)
#define BORINGSSL_HAS_UINT128
typedef __int128_t int128_t;
typedef __uint128_t uint128_t;
#endif
// Constant-time utility functions.
//
// The following methods return a bitmask of all ones (0xff...f) for true and 0
// for false. This is useful for choosing a value based on the result of a
// conditional in constant time. For example,
//
// if (a < b) {
// c = a;
// } else {
// c = b;
// }
//
// can be written as
//
// crypto_word lt = constant_time_lt_w(a, b);
// c = constant_time_select_w(lt, a, b);
// crypto_word is the type that most constant-time functions use. Ideally we
// would like it to be |size_t|, but NaCl builds in 64-bit mode with 32-bit
// pointers, which means that |size_t| can be 32 bits when |crypto_word| is 64
// bits.
#if defined(OPENSSL_64_BIT)
typedef uint64_t crypto_word;
#define CRYPTO_WORD_BITS (64u)
#elif defined(OPENSSL_32_BIT)
typedef uint32_t crypto_word;
#define CRYPTO_WORD_BITS (32u)
#else
#error "Must define either OPENSSL_32_BIT or OPENSSL_64_BIT"
#endif
#define CONSTTIME_TRUE_W ~((crypto_word)0)
#define CONSTTIME_FALSE_W ((crypto_word)0)
// value_barrier_w returns |a|, but prevents GCC and Clang from reasoning about
// the returned value. This is used to mitigate compilers undoing constant-time
// code, until we can express our requirements directly in the language.
//
// Note the compiler is aware that |value_barrier_w| has no side effects and
// always has the same output for a given input. This allows it to eliminate
// dead code, move computations across loops, and vectorize.
static inline crypto_word value_barrier_w(crypto_word a) {
#if !defined(OPENSSL_NO_ASM) && (defined(__GNUC__) || defined(__clang__))
__asm__("" : "+r"(a) : /* no inputs */);
#endif
return a;
}
// value_barrier_u32 behaves like |value_barrier_w| but takes a |uint32_t|.
static inline uint32_t value_barrier_u32(uint32_t a) {
#if !defined(OPENSSL_NO_ASM) && (defined(__GNUC__) || defined(__clang__))
__asm__("" : "+r"(a) : /* no inputs */);
#endif
return a;
}
// value_barrier_u64 behaves like |value_barrier_w| but takes a |uint64_t|.
static inline uint64_t value_barrier_u64(uint64_t a) {
#if !defined(OPENSSL_NO_ASM) && (defined(__GNUC__) || defined(__clang__))
__asm__("" : "+r"(a) : /* no inputs */);
#endif
return a;
}
// constant_time_msb_w returns the given value with the MSB copied to all the
// other bits.
static inline crypto_word constant_time_msb_w(crypto_word a) {
return 0u - (a >> (sizeof(a) * 8 - 1));
}
// constant_time_is_zero_w returns 0xff..f if a == 0 and 0 otherwise.
static inline crypto_word constant_time_is_zero_w(crypto_word a) {
// Here is an SMT-LIB verification of this formula:
//
// (define-fun is_zero ((a (_ BitVec 32))) (_ BitVec 32)
// (bvand (bvnot a) (bvsub a #x00000001))
// )
//
// (declare-fun a () (_ BitVec 32))
//
// (assert (not (= (= #x00000001 (bvlshr (is_zero a) #x0000001f)) (= a #x00000000))))
// (check-sat)
// (get-model)
return constant_time_msb_w(~a & (a - 1));
}
static inline crypto_word constant_time_is_nonzero_w(crypto_word a) {
return ~constant_time_is_zero_w(a);
}
// constant_time_eq_w returns 0xff..f if a == b and 0 otherwise.
static inline crypto_word constant_time_eq_w(crypto_word a,
crypto_word b) {
return constant_time_is_zero_w(a ^ b);
}
// constant_time_select_w returns (mask & a) | (~mask & b). When |mask| is all
// 1s or all 0s (as returned by the methods above), the select methods return
// either |a| (if |mask| is nonzero) or |b| (if |mask| is zero).
static inline crypto_word constant_time_select_w(crypto_word mask,
crypto_word a,
crypto_word b) {
// Clang recognizes this pattern as a select. While it usually transforms it
// to a cmov, it sometimes further transforms it into a branch, which we do
// not want.
//
// Adding barriers to both |mask| and |~mask| breaks the relationship between
// the two, which makes the compiler stick with bitmasks.
return (value_barrier_w(mask) & a) | (value_barrier_w(~mask) & b);
}
// Endianness conversions.
#if defined(__GNUC__) && __GNUC__ >= 2
static inline uint32_t CRYPTO_bswap4(uint32_t x) {
return __builtin_bswap32(x);
}
#elif defined(_MSC_VER)
#pragma warning(push, 3)
#include <stdlib.h>
#pragma warning(pop)
#pragma intrinsic(_byteswap_uint64, _byteswap_ulong)
static inline uint32_t CRYPTO_bswap4(uint32_t x) {
return _byteswap_ulong(x);
}
#endif
#if !defined(GFp_NOSTDLIBINC)
#include <string.h>
#endif
static inline void *GFp_memcpy(void *dst, const void *src, size_t n) {
#if !defined(GFp_NOSTDLIBINC)
if (n == 0) {
return dst;
}
return memcpy(dst, src, n);
#else
unsigned char *d = dst;
const unsigned char *s = src;
for (size_t i = 0; i < n; ++i) {
d[i] = s[i];
}
return dst;
#endif
}
static inline void *GFp_memset(void *dst, int c, size_t n) {
#if !defined(GFp_NOSTDLIBINC)
if (n == 0) {
return dst;
}
return memset(dst, c, n);
#else
unsigned char *d = dst;
for (size_t i = 0; i < n; ++i) {
d[i] = (unsigned char)c;
}
return dst;
#endif
}
#endif // OPENSSL_HEADER_CRYPTO_INTERNAL_H