658 lines
23 KiB
C
658 lines
23 KiB
C
/*
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* Copyright 2020-2023 The OpenSSL Project Authors. All Rights Reserved.
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* Copyright (c) 2020-2021, Intel Corporation. All Rights Reserved.
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*
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* Licensed under the Apache License 2.0 (the "License"). You may not use
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* this file except in compliance with the License. You can obtain a copy
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* in the file LICENSE in the source distribution or at
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* https://www.openssl.org/source/license.html
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*
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*
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* Originally written by Sergey Kirillov and Andrey Matyukov.
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* Special thanks to Ilya Albrekht for his valuable hints.
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* Intel Corporation
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*
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*/
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#include <openssl/opensslconf.h>
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#include <openssl/crypto.h>
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#include "rsaz_exp.h"
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#ifndef RSAZ_ENABLED
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NON_EMPTY_TRANSLATION_UNIT
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#else
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# include <assert.h>
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# include <string.h>
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# define ALIGN_OF(ptr, boundary) \
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((unsigned char *)(ptr) + (boundary - (((size_t)(ptr)) & (boundary - 1))))
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/* Internal radix */
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# define DIGIT_SIZE (52)
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/* 52-bit mask */
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# define DIGIT_MASK ((uint64_t)0xFFFFFFFFFFFFF)
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# define BITS2WORD8_SIZE(x) (((x) + 7) >> 3)
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# define BITS2WORD64_SIZE(x) (((x) + 63) >> 6)
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/* Number of registers required to hold |digits_num| amount of qword digits */
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# define NUMBER_OF_REGISTERS(digits_num, register_size) \
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(((digits_num) * 64 + (register_size) - 1) / (register_size))
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static ossl_inline uint64_t get_digit(const uint8_t *in, int in_len);
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static ossl_inline void put_digit(uint8_t *out, int out_len, uint64_t digit);
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static void to_words52(BN_ULONG *out, int out_len, const BN_ULONG *in,
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int in_bitsize);
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static void from_words52(BN_ULONG *bn_out, int out_bitsize, const BN_ULONG *in);
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static ossl_inline void set_bit(BN_ULONG *a, int idx);
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/* Number of |digit_size|-bit digits in |bitsize|-bit value */
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static ossl_inline int number_of_digits(int bitsize, int digit_size)
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{
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return (bitsize + digit_size - 1) / digit_size;
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}
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/*
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* For details of the methods declared below please refer to
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* crypto/bn/asm/rsaz-avx512.pl
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*
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* Naming conventions:
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* amm = Almost Montgomery Multiplication
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* ams = Almost Montgomery Squaring
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* 52xZZ - data represented as array of ZZ digits in 52-bit radix
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* _x1_/_x2_ - 1 or 2 independent inputs/outputs
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* _ifma256 - uses 256-bit wide IFMA ISA (AVX512_IFMA256)
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*/
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void ossl_rsaz_amm52x20_x1_ifma256(BN_ULONG *res, const BN_ULONG *a,
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const BN_ULONG *b, const BN_ULONG *m,
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BN_ULONG k0);
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void ossl_rsaz_amm52x20_x2_ifma256(BN_ULONG *out, const BN_ULONG *a,
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const BN_ULONG *b, const BN_ULONG *m,
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const BN_ULONG k0[2]);
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void ossl_extract_multiplier_2x20_win5(BN_ULONG *red_Y,
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const BN_ULONG *red_table,
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int red_table_idx1, int red_table_idx2);
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void ossl_rsaz_amm52x30_x1_ifma256(BN_ULONG *res, const BN_ULONG *a,
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const BN_ULONG *b, const BN_ULONG *m,
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BN_ULONG k0);
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void ossl_rsaz_amm52x30_x2_ifma256(BN_ULONG *out, const BN_ULONG *a,
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const BN_ULONG *b, const BN_ULONG *m,
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const BN_ULONG k0[2]);
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void ossl_extract_multiplier_2x30_win5(BN_ULONG *red_Y,
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const BN_ULONG *red_table,
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int red_table_idx1, int red_table_idx2);
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void ossl_rsaz_amm52x40_x1_ifma256(BN_ULONG *res, const BN_ULONG *a,
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const BN_ULONG *b, const BN_ULONG *m,
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BN_ULONG k0);
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void ossl_rsaz_amm52x40_x2_ifma256(BN_ULONG *out, const BN_ULONG *a,
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const BN_ULONG *b, const BN_ULONG *m,
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const BN_ULONG k0[2]);
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void ossl_extract_multiplier_2x40_win5(BN_ULONG *red_Y,
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const BN_ULONG *red_table,
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int red_table_idx1, int red_table_idx2);
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static int RSAZ_mod_exp_x2_ifma256(BN_ULONG *res, const BN_ULONG *base,
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const BN_ULONG *exp[2], const BN_ULONG *m,
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const BN_ULONG *rr, const BN_ULONG k0[2],
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int modulus_bitsize);
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/*
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* Dual Montgomery modular exponentiation using prime moduli of the
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* same bit size, optimized with AVX512 ISA.
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*
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* Input and output parameters for each exponentiation are independent and
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* denoted here by index |i|, i = 1..2.
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*
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* Input and output are all in regular 2^64 radix.
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*
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* Each moduli shall be |factor_size| bit size.
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*
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* Supported cases:
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* - 2x1024
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* - 2x1536
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* - 2x2048
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*
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* [out] res|i| - result of modular exponentiation: array of qword values
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* in regular (2^64) radix. Size of array shall be enough
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* to hold |factor_size| bits.
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* [in] base|i| - base
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* [in] exp|i| - exponent
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* [in] m|i| - moduli
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* [in] rr|i| - Montgomery parameter RR = R^2 mod m|i|
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* [in] k0_|i| - Montgomery parameter k0 = -1/m|i| mod 2^64
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* [in] factor_size - moduli bit size
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*
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* \return 0 in case of failure,
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* 1 in case of success.
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*/
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int ossl_rsaz_mod_exp_avx512_x2(BN_ULONG *res1,
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const BN_ULONG *base1,
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const BN_ULONG *exp1,
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const BN_ULONG *m1,
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const BN_ULONG *rr1,
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BN_ULONG k0_1,
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BN_ULONG *res2,
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const BN_ULONG *base2,
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const BN_ULONG *exp2,
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const BN_ULONG *m2,
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const BN_ULONG *rr2,
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BN_ULONG k0_2,
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int factor_size)
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{
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typedef void (*AMM)(BN_ULONG *res, const BN_ULONG *a,
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const BN_ULONG *b, const BN_ULONG *m, BN_ULONG k0);
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int ret = 0;
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/*
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* Number of word-size (BN_ULONG) digits to store exponent in redundant
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* representation.
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*/
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int exp_digits = number_of_digits(factor_size + 2, DIGIT_SIZE);
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int coeff_pow = 4 * (DIGIT_SIZE * exp_digits - factor_size);
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/* Number of YMM registers required to store exponent's digits */
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int ymm_regs_num = NUMBER_OF_REGISTERS(exp_digits, 256 /* ymm bit size */);
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/* Capacity of the register set (in qwords) to store exponent */
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int regs_capacity = ymm_regs_num * 4;
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BN_ULONG *base1_red, *m1_red, *rr1_red;
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BN_ULONG *base2_red, *m2_red, *rr2_red;
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BN_ULONG *coeff_red;
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BN_ULONG *storage = NULL;
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BN_ULONG *storage_aligned = NULL;
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int storage_len_bytes = 7 * regs_capacity * sizeof(BN_ULONG)
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+ 64 /* alignment */;
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const BN_ULONG *exp[2] = {0};
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BN_ULONG k0[2] = {0};
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/* AMM = Almost Montgomery Multiplication */
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AMM amm = NULL;
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switch (factor_size) {
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case 1024:
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amm = ossl_rsaz_amm52x20_x1_ifma256;
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break;
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case 1536:
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amm = ossl_rsaz_amm52x30_x1_ifma256;
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break;
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case 2048:
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amm = ossl_rsaz_amm52x40_x1_ifma256;
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break;
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default:
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goto err;
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}
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storage = (BN_ULONG *)OPENSSL_malloc(storage_len_bytes);
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if (storage == NULL)
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goto err;
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storage_aligned = (BN_ULONG *)ALIGN_OF(storage, 64);
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/* Memory layout for red(undant) representations */
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base1_red = storage_aligned;
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base2_red = storage_aligned + 1 * regs_capacity;
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m1_red = storage_aligned + 2 * regs_capacity;
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m2_red = storage_aligned + 3 * regs_capacity;
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rr1_red = storage_aligned + 4 * regs_capacity;
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rr2_red = storage_aligned + 5 * regs_capacity;
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coeff_red = storage_aligned + 6 * regs_capacity;
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/* Convert base_i, m_i, rr_i, from regular to 52-bit radix */
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to_words52(base1_red, regs_capacity, base1, factor_size);
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to_words52(base2_red, regs_capacity, base2, factor_size);
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to_words52(m1_red, regs_capacity, m1, factor_size);
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to_words52(m2_red, regs_capacity, m2, factor_size);
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to_words52(rr1_red, regs_capacity, rr1, factor_size);
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to_words52(rr2_red, regs_capacity, rr2, factor_size);
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/*
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* Compute target domain Montgomery converters RR' for each modulus
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* based on precomputed original domain's RR.
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*
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* RR -> RR' transformation steps:
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* (1) coeff = 2^k
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* (2) t = AMM(RR,RR) = RR^2 / R' mod m
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* (3) RR' = AMM(t, coeff) = RR^2 * 2^k / R'^2 mod m
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* where
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* k = 4 * (52 * digits52 - modlen)
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* R = 2^(64 * ceil(modlen/64)) mod m
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* RR = R^2 mod m
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* R' = 2^(52 * ceil(modlen/52)) mod m
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*
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* EX/ modlen = 1024: k = 64, RR = 2^2048 mod m, RR' = 2^2080 mod m
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*/
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memset(coeff_red, 0, exp_digits * sizeof(BN_ULONG));
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/* (1) in reduced domain representation */
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set_bit(coeff_red, 64 * (int)(coeff_pow / 52) + coeff_pow % 52);
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amm(rr1_red, rr1_red, rr1_red, m1_red, k0_1); /* (2) for m1 */
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amm(rr1_red, rr1_red, coeff_red, m1_red, k0_1); /* (3) for m1 */
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amm(rr2_red, rr2_red, rr2_red, m2_red, k0_2); /* (2) for m2 */
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amm(rr2_red, rr2_red, coeff_red, m2_red, k0_2); /* (3) for m2 */
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exp[0] = exp1;
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exp[1] = exp2;
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k0[0] = k0_1;
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k0[1] = k0_2;
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/* Dual (2-exps in parallel) exponentiation */
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ret = RSAZ_mod_exp_x2_ifma256(rr1_red, base1_red, exp, m1_red, rr1_red,
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k0, factor_size);
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if (!ret)
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goto err;
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/* Convert rr_i back to regular radix */
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from_words52(res1, factor_size, rr1_red);
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from_words52(res2, factor_size, rr2_red);
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/* bn_reduce_once_in_place expects number of BN_ULONG, not bit size */
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factor_size /= sizeof(BN_ULONG) * 8;
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bn_reduce_once_in_place(res1, /*carry=*/0, m1, storage, factor_size);
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bn_reduce_once_in_place(res2, /*carry=*/0, m2, storage, factor_size);
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err:
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if (storage != NULL) {
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OPENSSL_cleanse(storage, storage_len_bytes);
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OPENSSL_free(storage);
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}
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return ret;
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}
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/*
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* Dual {1024,1536,2048}-bit w-ary modular exponentiation using prime moduli of
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* the same bit size using Almost Montgomery Multiplication, optimized with
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* AVX512_IFMA256 ISA.
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*
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* The parameter w (window size) = 5.
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*
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* [out] res - result of modular exponentiation: 2x{20,30,40} qword
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* values in 2^52 radix.
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* [in] base - base (2x{20,30,40} qword values in 2^52 radix)
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* [in] exp - array of 2 pointers to {16,24,32} qword values in 2^64 radix.
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* Exponent is not converted to redundant representation.
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* [in] m - moduli (2x{20,30,40} qword values in 2^52 radix)
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* [in] rr - Montgomery parameter for 2 moduli:
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* RR(1024) = 2^2080 mod m.
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* RR(1536) = 2^3120 mod m.
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* RR(2048) = 2^4160 mod m.
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* (2x{20,30,40} qword values in 2^52 radix)
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* [in] k0 - Montgomery parameter for 2 moduli: k0 = -1/m mod 2^64
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*
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* \return (void).
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*/
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int RSAZ_mod_exp_x2_ifma256(BN_ULONG *out,
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const BN_ULONG *base,
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const BN_ULONG *exp[2],
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const BN_ULONG *m,
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const BN_ULONG *rr,
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const BN_ULONG k0[2],
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int modulus_bitsize)
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{
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typedef void (*DAMM)(BN_ULONG *res, const BN_ULONG *a,
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const BN_ULONG *b, const BN_ULONG *m,
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const BN_ULONG k0[2]);
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typedef void (*DEXTRACT)(BN_ULONG *res, const BN_ULONG *red_table,
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int red_table_idx, int tbl_idx);
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int ret = 0;
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int idx;
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/* Exponent window size */
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int exp_win_size = 5;
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int exp_win_mask = (1U << exp_win_size) - 1;
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/*
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* Number of digits (64-bit words) in redundant representation to handle
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* modulus bits
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*/
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int red_digits = 0;
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int exp_digits = 0;
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BN_ULONG *storage = NULL;
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BN_ULONG *storage_aligned = NULL;
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int storage_len_bytes = 0;
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/* Red(undant) result Y and multiplier X */
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BN_ULONG *red_Y = NULL; /* [2][red_digits] */
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BN_ULONG *red_X = NULL; /* [2][red_digits] */
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/* Pre-computed table of base powers */
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BN_ULONG *red_table = NULL; /* [1U << exp_win_size][2][red_digits] */
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/* Expanded exponent */
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BN_ULONG *expz = NULL; /* [2][exp_digits + 1] */
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/* Dual AMM */
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DAMM damm = NULL;
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/* Extractor from red_table */
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DEXTRACT extract = NULL;
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/*
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* Squaring is done using multiplication now. That can be a subject of
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* optimization in future.
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*/
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# define DAMS(r,a,m,k0) damm((r),(a),(a),(m),(k0))
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switch (modulus_bitsize) {
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case 1024:
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red_digits = 20;
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exp_digits = 16;
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damm = ossl_rsaz_amm52x20_x2_ifma256;
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extract = ossl_extract_multiplier_2x20_win5;
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break;
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case 1536:
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/* Extended with 2 digits padding to avoid mask ops in high YMM register */
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red_digits = 30 + 2;
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exp_digits = 24;
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damm = ossl_rsaz_amm52x30_x2_ifma256;
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extract = ossl_extract_multiplier_2x30_win5;
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break;
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case 2048:
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red_digits = 40;
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exp_digits = 32;
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damm = ossl_rsaz_amm52x40_x2_ifma256;
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extract = ossl_extract_multiplier_2x40_win5;
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break;
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default:
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goto err;
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}
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storage_len_bytes = (2 * red_digits /* red_Y */
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+ 2 * red_digits /* red_X */
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+ 2 * red_digits * (1U << exp_win_size) /* red_table */
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+ 2 * (exp_digits + 1)) /* expz */
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* sizeof(BN_ULONG)
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+ 64; /* alignment */
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storage = (BN_ULONG *)OPENSSL_zalloc(storage_len_bytes);
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if (storage == NULL)
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goto err;
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storage_aligned = (BN_ULONG *)ALIGN_OF(storage, 64);
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red_Y = storage_aligned;
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red_X = red_Y + 2 * red_digits;
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red_table = red_X + 2 * red_digits;
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expz = red_table + 2 * red_digits * (1U << exp_win_size);
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/*
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* Compute table of powers base^i, i = 0, ..., (2^EXP_WIN_SIZE) - 1
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* table[0] = mont(x^0) = mont(1)
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* table[1] = mont(x^1) = mont(x)
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*/
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red_X[0 * red_digits] = 1;
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red_X[1 * red_digits] = 1;
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damm(&red_table[0 * 2 * red_digits], (const BN_ULONG*)red_X, rr, m, k0);
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damm(&red_table[1 * 2 * red_digits], base, rr, m, k0);
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for (idx = 1; idx < (int)((1U << exp_win_size) / 2); idx++) {
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DAMS(&red_table[(2 * idx + 0) * 2 * red_digits],
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&red_table[(1 * idx) * 2 * red_digits], m, k0);
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damm(&red_table[(2 * idx + 1) * 2 * red_digits],
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&red_table[(2 * idx) * 2 * red_digits],
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&red_table[1 * 2 * red_digits], m, k0);
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}
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/* Copy and expand exponents */
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memcpy(&expz[0 * (exp_digits + 1)], exp[0], exp_digits * sizeof(BN_ULONG));
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expz[1 * (exp_digits + 1) - 1] = 0;
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memcpy(&expz[1 * (exp_digits + 1)], exp[1], exp_digits * sizeof(BN_ULONG));
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expz[2 * (exp_digits + 1) - 1] = 0;
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/* Exponentiation */
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{
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const int rem = modulus_bitsize % exp_win_size;
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const BN_ULONG table_idx_mask = exp_win_mask;
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int exp_bit_no = modulus_bitsize - rem;
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int exp_chunk_no = exp_bit_no / 64;
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int exp_chunk_shift = exp_bit_no % 64;
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BN_ULONG red_table_idx_0, red_table_idx_1;
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/*
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* If rem == 0, then
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* exp_bit_no = modulus_bitsize - exp_win_size
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* However, this isn't possible because rem is { 1024, 1536, 2048 } % 5
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* which is { 4, 1, 3 } respectively.
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*
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* If this assertion ever fails the fix above is easy.
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*/
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OPENSSL_assert(rem != 0);
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/* Process 1-st exp window - just init result */
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red_table_idx_0 = expz[exp_chunk_no + 0 * (exp_digits + 1)];
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red_table_idx_1 = expz[exp_chunk_no + 1 * (exp_digits + 1)];
|
|
|
|
/*
|
|
* The function operates with fixed moduli sizes divisible by 64,
|
|
* thus table index here is always in supported range [0, EXP_WIN_SIZE).
|
|
*/
|
|
red_table_idx_0 >>= exp_chunk_shift;
|
|
red_table_idx_1 >>= exp_chunk_shift;
|
|
|
|
extract(&red_Y[0 * red_digits], (const BN_ULONG*)red_table, (int)red_table_idx_0, (int)red_table_idx_1);
|
|
|
|
/* Process other exp windows */
|
|
for (exp_bit_no -= exp_win_size; exp_bit_no >= 0; exp_bit_no -= exp_win_size) {
|
|
/* Extract pre-computed multiplier from the table */
|
|
{
|
|
BN_ULONG T;
|
|
|
|
exp_chunk_no = exp_bit_no / 64;
|
|
exp_chunk_shift = exp_bit_no % 64;
|
|
{
|
|
red_table_idx_0 = expz[exp_chunk_no + 0 * (exp_digits + 1)];
|
|
T = expz[exp_chunk_no + 1 + 0 * (exp_digits + 1)];
|
|
|
|
red_table_idx_0 >>= exp_chunk_shift;
|
|
/*
|
|
* Get additional bits from then next quadword
|
|
* when 64-bit boundaries are crossed.
|
|
*/
|
|
if (exp_chunk_shift > 64 - exp_win_size) {
|
|
T <<= (64 - exp_chunk_shift);
|
|
red_table_idx_0 ^= T;
|
|
}
|
|
red_table_idx_0 &= table_idx_mask;
|
|
}
|
|
{
|
|
red_table_idx_1 = expz[exp_chunk_no + 1 * (exp_digits + 1)];
|
|
T = expz[exp_chunk_no + 1 + 1 * (exp_digits + 1)];
|
|
|
|
red_table_idx_1 >>= exp_chunk_shift;
|
|
/*
|
|
* Get additional bits from then next quadword
|
|
* when 64-bit boundaries are crossed.
|
|
*/
|
|
if (exp_chunk_shift > 64 - exp_win_size) {
|
|
T <<= (64 - exp_chunk_shift);
|
|
red_table_idx_1 ^= T;
|
|
}
|
|
red_table_idx_1 &= table_idx_mask;
|
|
}
|
|
|
|
extract(&red_X[0 * red_digits], (const BN_ULONG*)red_table, (int)red_table_idx_0, (int)red_table_idx_1);
|
|
}
|
|
|
|
/* Series of squaring */
|
|
DAMS((BN_ULONG*)red_Y, (const BN_ULONG*)red_Y, m, k0);
|
|
DAMS((BN_ULONG*)red_Y, (const BN_ULONG*)red_Y, m, k0);
|
|
DAMS((BN_ULONG*)red_Y, (const BN_ULONG*)red_Y, m, k0);
|
|
DAMS((BN_ULONG*)red_Y, (const BN_ULONG*)red_Y, m, k0);
|
|
DAMS((BN_ULONG*)red_Y, (const BN_ULONG*)red_Y, m, k0);
|
|
|
|
damm((BN_ULONG*)red_Y, (const BN_ULONG*)red_Y, (const BN_ULONG*)red_X, m, k0);
|
|
}
|
|
}
|
|
|
|
/*
|
|
*
|
|
* NB: After the last AMM of exponentiation in Montgomery domain, the result
|
|
* may be (modulus_bitsize + 1), but the conversion out of Montgomery domain
|
|
* performs an AMM(x,1) which guarantees that the final result is less than
|
|
* |m|, so no conditional subtraction is needed here. See [1] for details.
|
|
*
|
|
* [1] Gueron, S. Efficient software implementations of modular exponentiation.
|
|
* DOI: 10.1007/s13389-012-0031-5
|
|
*/
|
|
|
|
/* Convert result back in regular 2^52 domain */
|
|
memset(red_X, 0, 2 * red_digits * sizeof(BN_ULONG));
|
|
red_X[0 * red_digits] = 1;
|
|
red_X[1 * red_digits] = 1;
|
|
damm(out, (const BN_ULONG*)red_Y, (const BN_ULONG*)red_X, m, k0);
|
|
|
|
ret = 1;
|
|
|
|
err:
|
|
if (storage != NULL) {
|
|
/* Clear whole storage */
|
|
OPENSSL_cleanse(storage, storage_len_bytes);
|
|
OPENSSL_free(storage);
|
|
}
|
|
|
|
#undef DAMS
|
|
return ret;
|
|
}
|
|
|
|
static ossl_inline uint64_t get_digit(const uint8_t *in, int in_len)
|
|
{
|
|
uint64_t digit = 0;
|
|
|
|
assert(in != NULL);
|
|
assert(in_len <= 8);
|
|
|
|
for (; in_len > 0; in_len--) {
|
|
digit <<= 8;
|
|
digit += (uint64_t)(in[in_len - 1]);
|
|
}
|
|
return digit;
|
|
}
|
|
|
|
/*
|
|
* Convert array of words in regular (base=2^64) representation to array of
|
|
* words in redundant (base=2^52) one.
|
|
*/
|
|
static void to_words52(BN_ULONG *out, int out_len,
|
|
const BN_ULONG *in, int in_bitsize)
|
|
{
|
|
uint8_t *in_str = NULL;
|
|
|
|
assert(out != NULL);
|
|
assert(in != NULL);
|
|
/* Check destination buffer capacity */
|
|
assert(out_len >= number_of_digits(in_bitsize, DIGIT_SIZE));
|
|
|
|
in_str = (uint8_t *)in;
|
|
|
|
for (; in_bitsize >= (2 * DIGIT_SIZE); in_bitsize -= (2 * DIGIT_SIZE), out += 2) {
|
|
uint64_t digit;
|
|
|
|
memcpy(&digit, in_str, sizeof(digit));
|
|
out[0] = digit & DIGIT_MASK;
|
|
in_str += 6;
|
|
memcpy(&digit, in_str, sizeof(digit));
|
|
out[1] = (digit >> 4) & DIGIT_MASK;
|
|
in_str += 7;
|
|
out_len -= 2;
|
|
}
|
|
|
|
if (in_bitsize > DIGIT_SIZE) {
|
|
uint64_t digit = get_digit(in_str, 7);
|
|
|
|
out[0] = digit & DIGIT_MASK;
|
|
in_str += 6;
|
|
in_bitsize -= DIGIT_SIZE;
|
|
digit = get_digit(in_str, BITS2WORD8_SIZE(in_bitsize));
|
|
out[1] = digit >> 4;
|
|
out += 2;
|
|
out_len -= 2;
|
|
} else if (in_bitsize > 0) {
|
|
out[0] = get_digit(in_str, BITS2WORD8_SIZE(in_bitsize));
|
|
out++;
|
|
out_len--;
|
|
}
|
|
|
|
while (out_len > 0) {
|
|
*out = 0;
|
|
out_len--;
|
|
out++;
|
|
}
|
|
}
|
|
|
|
static ossl_inline void put_digit(uint8_t *out, int out_len, uint64_t digit)
|
|
{
|
|
assert(out != NULL);
|
|
assert(out_len <= 8);
|
|
|
|
for (; out_len > 0; out_len--) {
|
|
*out++ = (uint8_t)(digit & 0xFF);
|
|
digit >>= 8;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Convert array of words in redundant (base=2^52) representation to array of
|
|
* words in regular (base=2^64) one.
|
|
*/
|
|
static void from_words52(BN_ULONG *out, int out_bitsize, const BN_ULONG *in)
|
|
{
|
|
int i;
|
|
int out_len = BITS2WORD64_SIZE(out_bitsize);
|
|
|
|
assert(out != NULL);
|
|
assert(in != NULL);
|
|
|
|
for (i = 0; i < out_len; i++)
|
|
out[i] = 0;
|
|
|
|
{
|
|
uint8_t *out_str = (uint8_t *)out;
|
|
|
|
for (; out_bitsize >= (2 * DIGIT_SIZE);
|
|
out_bitsize -= (2 * DIGIT_SIZE), in += 2) {
|
|
uint64_t digit;
|
|
|
|
digit = in[0];
|
|
memcpy(out_str, &digit, sizeof(digit));
|
|
out_str += 6;
|
|
digit = digit >> 48 | in[1] << 4;
|
|
memcpy(out_str, &digit, sizeof(digit));
|
|
out_str += 7;
|
|
}
|
|
|
|
if (out_bitsize > DIGIT_SIZE) {
|
|
put_digit(out_str, 7, in[0]);
|
|
out_str += 6;
|
|
out_bitsize -= DIGIT_SIZE;
|
|
put_digit(out_str, BITS2WORD8_SIZE(out_bitsize),
|
|
(in[1] << 4 | in[0] >> 48));
|
|
} else if (out_bitsize) {
|
|
put_digit(out_str, BITS2WORD8_SIZE(out_bitsize), in[0]);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Set bit at index |idx| in the words array |a|.
|
|
* It does not do any boundaries checks, make sure the index is valid before
|
|
* calling the function.
|
|
*/
|
|
static ossl_inline void set_bit(BN_ULONG *a, int idx)
|
|
{
|
|
assert(a != NULL);
|
|
|
|
{
|
|
int i, j;
|
|
|
|
i = idx / BN_BITS2;
|
|
j = idx % BN_BITS2;
|
|
a[i] |= (((BN_ULONG)1) << j);
|
|
}
|
|
}
|
|
|
|
#endif
|