/* Copyright (C) 1995-1997 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) 1998-2006 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). * */ /* ==================================================================== * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED. * * Portions of the attached software ("Contribution") are developed by * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project. * * The Contribution is licensed pursuant to the Eric Young open source * license provided above. * * The binary polynomial arithmetic software is originally written by * Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems * Laboratories. */ #ifndef OPENSSL_HEADER_BN_INTERNAL_H #define OPENSSL_HEADER_BN_INTERNAL_H #include #if defined(OPENSSL_X86_64) && defined(_MSC_VER) OPENSSL_MSVC_PRAGMA(warning(push, 3)) #include OPENSSL_MSVC_PRAGMA(warning(pop)) #pragma intrinsic(__umulh, _umul128) #endif #include "../../internal.h" #if defined(__cplusplus) extern "C" { #endif #if defined(OPENSSL_64_BIT) #if defined(BORINGSSL_HAS_UINT128) // MSVC doesn't support two-word integers on 64-bit. #define BN_ULLONG uint128_t #if defined(BORINGSSL_CAN_DIVIDE_UINT128) #define BN_CAN_DIVIDE_ULLONG #endif #endif #define BN_BITS2 64 #define BN_BYTES 8 #define BN_BITS4 32 #define BN_MASK2 (0xffffffffffffffffUL) #define BN_MASK2l (0xffffffffUL) #define BN_MASK2h (0xffffffff00000000UL) #define BN_MASK2h1 (0xffffffff80000000UL) #define BN_MONT_CTX_N0_LIMBS 1 #define BN_DEC_CONV (10000000000000000000UL) #define BN_DEC_NUM 19 #define TOBN(hi, lo) ((BN_ULONG)(hi) << 32 | (lo)) #elif defined(OPENSSL_32_BIT) #define BN_ULLONG uint64_t #define BN_CAN_DIVIDE_ULLONG #define BN_BITS2 32 #define BN_BYTES 4 #define BN_BITS4 16 #define BN_MASK2 (0xffffffffUL) #define BN_MASK2l (0xffffUL) #define BN_MASK2h1 (0xffff8000UL) #define BN_MASK2h (0xffff0000UL) // On some 32-bit platforms, Montgomery multiplication is done using 64-bit // arithmetic with SIMD instructions. On such platforms, |BN_MONT_CTX::n0| // needs to be two words long. Only certain 32-bit platforms actually make use // of n0[1] and shorter R value would suffice for the others. However, // currently only the assembly files know which is which. #define BN_MONT_CTX_N0_LIMBS 2 #define BN_DEC_CONV (1000000000UL) #define BN_DEC_NUM 9 #define TOBN(hi, lo) (lo), (hi) #else #error "Must define either OPENSSL_32_BIT or OPENSSL_64_BIT" #endif #if !defined(OPENSSL_NO_ASM) && (defined(__GNUC__) || defined(__clang__)) #define BN_CAN_USE_INLINE_ASM #endif // MOD_EXP_CTIME_ALIGN is the alignment needed for |BN_mod_exp_mont_consttime|'s // tables. // // TODO(davidben): Historically, this alignment came from cache line // assumptions, which we've since removed. Is 64-byte alignment still necessary // or ideal? The true alignment requirement seems to now be 32 bytes, coming // from RSAZ's use of VMOVDQA to a YMM register. Non-x86_64 has even fewer // requirements. #define MOD_EXP_CTIME_ALIGN 64 // MOD_EXP_CTIME_STORAGE_LEN is the number of |BN_ULONG|s needed for the // |BN_mod_exp_mont_consttime| stack-allocated storage buffer. The buffer is // just the right size for the RSAZ and is about ~1KB larger than what's // necessary (4480 bytes) for 1024-bit inputs. #define MOD_EXP_CTIME_STORAGE_LEN \ (((320u * 3u) + (32u * 9u * 16u)) / sizeof(BN_ULONG)) #define STATIC_BIGNUM(x) \ { \ (BN_ULONG *)(x), sizeof(x) / sizeof(BN_ULONG), \ sizeof(x) / sizeof(BN_ULONG), 0, BN_FLG_STATIC_DATA \ } #if defined(BN_ULLONG) #define Lw(t) ((BN_ULONG)(t)) #define Hw(t) ((BN_ULONG)((t) >> BN_BITS2)) #endif // bn_minimal_width returns the minimal number of words needed to represent // |bn|. int bn_minimal_width(const BIGNUM *bn); // bn_set_minimal_width sets |bn->width| to |bn_minimal_width(bn)|. If |bn| is // zero, |bn->neg| is set to zero. void bn_set_minimal_width(BIGNUM *bn); // bn_wexpand ensures that |bn| has at least |words| works of space without // altering its value. It returns one on success or zero on allocation // failure. int bn_wexpand(BIGNUM *bn, size_t words); // bn_expand acts the same as |bn_wexpand|, but takes a number of bits rather // than a number of words. int bn_expand(BIGNUM *bn, size_t bits); // bn_resize_words adjusts |bn->width| to be |words|. It returns one on success // and zero on allocation error or if |bn|'s value is too large. OPENSSL_EXPORT int bn_resize_words(BIGNUM *bn, size_t words); // bn_select_words sets |r| to |a| if |mask| is all ones or |b| if |mask| is // all zeros. void bn_select_words(BN_ULONG *r, BN_ULONG mask, const BN_ULONG *a, const BN_ULONG *b, size_t num); // bn_set_words sets |bn| to the value encoded in the |num| words in |words|, // least significant word first. int bn_set_words(BIGNUM *bn, const BN_ULONG *words, size_t num); // bn_set_static_words acts like |bn_set_words|, but doesn't copy the data. A // flag is set on |bn| so that |BN_free| won't attempt to free the data. // // The |STATIC_BIGNUM| macro is probably a better solution for this outside of // the FIPS module. Inside of the FIPS module that macro generates rel.ro data, // which doesn't work with FIPS requirements. void bn_set_static_words(BIGNUM *bn, const BN_ULONG *words, size_t num); // bn_fits_in_words returns one if |bn| may be represented in |num| words, plus // a sign bit, and zero otherwise. int bn_fits_in_words(const BIGNUM *bn, size_t num); // bn_copy_words copies the value of |bn| to |out| and returns one if the value // is representable in |num| words. Otherwise, it returns zero. int bn_copy_words(BN_ULONG *out, size_t num, const BIGNUM *bn); // bn_assert_fits_in_bytes asserts that |bn| fits in |num| bytes. This is a // no-op in release builds, but triggers an assert in debug builds, and // declassifies all bytes which are therefore known to be zero in constant-time // validation. void bn_assert_fits_in_bytes(const BIGNUM *bn, size_t num); // bn_mul_add_words multiples |ap| by |w|, adds the result to |rp|, and places // the result in |rp|. |ap| and |rp| must both be |num| words long. It returns // the carry word of the operation. |ap| and |rp| may be equal but otherwise may // not alias. BN_ULONG bn_mul_add_words(BN_ULONG *rp, const BN_ULONG *ap, size_t num, BN_ULONG w); // bn_mul_words multiples |ap| by |w| and places the result in |rp|. |ap| and // |rp| must both be |num| words long. It returns the carry word of the // operation. |ap| and |rp| may be equal but otherwise may not alias. BN_ULONG bn_mul_words(BN_ULONG *rp, const BN_ULONG *ap, size_t num, BN_ULONG w); // bn_sqr_words sets |rp[2*i]| and |rp[2*i+1]| to |ap[i]|'s square, for all |i| // up to |num|. |ap| is an array of |num| words and |rp| an array of |2*num| // words. |ap| and |rp| may not alias. // // This gives the contribution of the |ap[i]*ap[i]| terms when squaring |ap|. void bn_sqr_words(BN_ULONG *rp, const BN_ULONG *ap, size_t num); // bn_add_words adds |ap| to |bp| and places the result in |rp|, each of which // are |num| words long. It returns the carry bit, which is one if the operation // overflowed and zero otherwise. Any pair of |ap|, |bp|, and |rp| may be equal // to each other but otherwise may not alias. BN_ULONG bn_add_words(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp, size_t num); // bn_sub_words subtracts |bp| from |ap| and places the result in |rp|. It // returns the borrow bit, which is one if the computation underflowed and zero // otherwise. Any pair of |ap|, |bp|, and |rp| may be equal to each other but // otherwise may not alias. BN_ULONG bn_sub_words(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp, size_t num); // bn_mul_comba4 sets |r| to the product of |a| and |b|. void bn_mul_comba4(BN_ULONG r[8], const BN_ULONG a[4], const BN_ULONG b[4]); // bn_mul_comba8 sets |r| to the product of |a| and |b|. void bn_mul_comba8(BN_ULONG r[16], const BN_ULONG a[8], const BN_ULONG b[8]); // bn_sqr_comba8 sets |r| to |a|^2. void bn_sqr_comba8(BN_ULONG r[16], const BN_ULONG a[8]); // bn_sqr_comba4 sets |r| to |a|^2. void bn_sqr_comba4(BN_ULONG r[8], const BN_ULONG a[4]); // bn_less_than_words returns one if |a| < |b| and zero otherwise, where |a| // and |b| both are |len| words long. It runs in constant time. int bn_less_than_words(const BN_ULONG *a, const BN_ULONG *b, size_t len); // bn_in_range_words returns one if |min_inclusive| <= |a| < |max_exclusive|, // where |a| and |max_exclusive| both are |len| words long. |a| and // |max_exclusive| are treated as secret. int bn_in_range_words(const BN_ULONG *a, BN_ULONG min_inclusive, const BN_ULONG *max_exclusive, size_t len); // bn_rand_range_words sets |out| to a uniformly distributed random number from // |min_inclusive| to |max_exclusive|. Both |out| and |max_exclusive| are |len| // words long. // // This function runs in time independent of the result, but |min_inclusive| and // |max_exclusive| are public data. (Information about the range is unavoidably // leaked by how many iterations it took to select a number.) int bn_rand_range_words(BN_ULONG *out, BN_ULONG min_inclusive, const BN_ULONG *max_exclusive, size_t len, const uint8_t additional_data[32]); // bn_range_secret_range behaves like |BN_rand_range_ex|, but treats // |max_exclusive| as secret. Because of this constraint, the distribution of // values returned is more complex. // // Rather than repeatedly generating values until one is in range, which would // leak information, it generates one value. If the value is in range, it sets // |*out_is_uniform| to one. Otherwise, it sets |*out_is_uniform| to zero, // fixing up the value to force it in range. // // The subset of calls to |bn_rand_secret_range| which set |*out_is_uniform| to // one are uniformly distributed in the target range. Calls overall are not. // This function is intended for use in situations where the extra values are // still usable and where the number of iterations needed to reach the target // number of uniform outputs may be blinded for negligible probabilities of // timing leaks. // // Although this function treats |max_exclusive| as secret, it treats the number // of bits in |max_exclusive| as public. int bn_rand_secret_range(BIGNUM *r, int *out_is_uniform, BN_ULONG min_inclusive, const BIGNUM *max_exclusive); // BN_MONTGOMERY_MAX_WORDS is the maximum numer of words allowed in a |BIGNUM| // used with Montgomery reduction. Ideally this limit would be applied to all // |BIGNUM|s, in |bn_wexpand|, but the exactfloat library needs to create 8 MiB // values for other operations. #define BN_MONTGOMERY_MAX_WORDS (8 * 1024 / sizeof(BN_ULONG)) #if !defined(OPENSSL_NO_ASM) && \ (defined(OPENSSL_X86) || defined(OPENSSL_X86_64) || \ defined(OPENSSL_ARM) || defined(OPENSSL_AARCH64)) #define OPENSSL_BN_ASM_MONT // bn_mul_mont writes |ap| * |bp| mod |np| to |rp|, each |num| words // long. Inputs and outputs are in Montgomery form. |n0| is a pointer to the // corresponding field in |BN_MONT_CTX|. It returns one if |bn_mul_mont| handles // inputs of this size and zero otherwise. // // If at least one of |ap| or |bp| is fully reduced, |rp| will be fully reduced. // If neither is fully-reduced, the output may not be either. // // This function allocates |num| words on the stack, so |num| should be at most // |BN_MONTGOMERY_MAX_WORDS|. // // TODO(davidben): The x86_64 implementation expects a 32-bit input and masks // off upper bits. The aarch64 implementation expects a 64-bit input and does // not. |size_t| is the safer option but not strictly correct for x86_64. But // the |BN_MONTGOMERY_MAX_WORDS| bound makes this moot. // // See also discussion in |ToWord| in abi_test.h for notes on smaller-than-word // inputs. int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp, const BN_ULONG *np, const BN_ULONG *n0, size_t num); #endif #if !defined(OPENSSL_NO_ASM) && defined(OPENSSL_X86_64) #define OPENSSL_BN_ASM_MONT5 // bn_mul_mont_gather5 multiples loads index |power| of |table|, multiplies it // by |ap| modulo |np|, and stores the result in |rp|. The values are |num| // words long and represented in Montgomery form. |n0| is a pointer to the // corresponding field in |BN_MONT_CTX|. |table| must be aligned to at least // 16 bytes. |power| must be less than 32 and is treated as secret. // // WARNING: This function implements Almost Montgomery Multiplication from // https://eprint.iacr.org/2011/239. The inputs do not need to be fully reduced. // However, even if they are fully reduced, the output may not be. void bn_mul_mont_gather5(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *table, const BN_ULONG *np, const BN_ULONG *n0, int num, int power); // bn_scatter5 stores |inp| to index |power| of |table|. |inp| and each entry of // |table| are |num| words long. |power| must be less than 32 and is treated as // public. |table| must be 32*|num| words long. |table| must be aligned to at // least 16 bytes. void bn_scatter5(const BN_ULONG *inp, size_t num, BN_ULONG *table, size_t power); // bn_gather5 loads index |power| of |table| and stores it in |out|. |out| and // each entry of |table| are |num| words long. |power| must be less than 32 and // is treated as secret. |table| must be aligned to at least 16 bytes. void bn_gather5(BN_ULONG *out, size_t num, const BN_ULONG *table, size_t power); // bn_power5 squares |ap| five times and multiplies it by the value stored at // index |power| of |table|, modulo |np|. It stores the result in |rp|. The // values are |num| words long and represented in Montgomery form. |n0| is a // pointer to the corresponding field in |BN_MONT_CTX|. |num| must be divisible // by 8. |power| must be less than 32 and is treated as secret. // // WARNING: This function implements Almost Montgomery Multiplication from // https://eprint.iacr.org/2011/239. The inputs do not need to be fully reduced. // However, even if they are fully reduced, the output may not be. void bn_power5(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *table, const BN_ULONG *np, const BN_ULONG *n0, int num, int power); #endif // !OPENSSL_NO_ASM && OPENSSL_X86_64 uint64_t bn_mont_n0(const BIGNUM *n); // bn_mont_ctx_set_RR_consttime initializes |mont->RR|. It returns one on // success and zero on error. |mont->N| and |mont->n0| must have been // initialized already. The bit width of |mont->N| is assumed public, but // |mont->N| is otherwise treated as secret. int bn_mont_ctx_set_RR_consttime(BN_MONT_CTX *mont, BN_CTX *ctx); #if defined(_MSC_VER) #if defined(OPENSSL_X86_64) #define BN_UMULT_LOHI(low, high, a, b) ((low) = _umul128((a), (b), &(high))) #elif defined(OPENSSL_AARCH64) #define BN_UMULT_LOHI(low, high, a, b) \ do { \ const BN_ULONG _a = (a); \ const BN_ULONG _b = (b); \ (low) = _a * _b; \ (high) = __umulh(_a, _b); \ } while (0) #endif #endif // _MSC_VER #if !defined(BN_ULLONG) && !defined(BN_UMULT_LOHI) #error "Either BN_ULLONG or BN_UMULT_LOHI must be defined on every platform." #endif // bn_jacobi returns the Jacobi symbol of |a| and |b| (which is -1, 0 or 1), or // -2 on error. int bn_jacobi(const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx); // bn_is_bit_set_words returns one if bit |bit| is set in |a| and zero // otherwise. int bn_is_bit_set_words(const BN_ULONG *a, size_t num, size_t bit); // bn_one_to_montgomery sets |r| to one in Montgomery form. It returns one on // success and zero on error. This function treats the bit width of the modulus // as public. int bn_one_to_montgomery(BIGNUM *r, const BN_MONT_CTX *mont, BN_CTX *ctx); // bn_less_than_montgomery_R returns one if |bn| is less than the Montgomery R // value for |mont| and zero otherwise. int bn_less_than_montgomery_R(const BIGNUM *bn, const BN_MONT_CTX *mont); // bn_mod_u16_consttime returns |bn| mod |d|, ignoring |bn|'s sign bit. It runs // in time independent of the value of |bn|, but it treats |d| as public. OPENSSL_EXPORT uint16_t bn_mod_u16_consttime(const BIGNUM *bn, uint16_t d); // bn_odd_number_is_obviously_composite returns one if |bn| is divisible by one // of the first several odd primes and zero otherwise. int bn_odd_number_is_obviously_composite(const BIGNUM *bn); // A BN_MILLER_RABIN stores state common to each Miller-Rabin iteration. It is // initialized within an existing |BN_CTX| scope and may not be used after // that scope is released with |BN_CTX_end|. Field names match those in FIPS // 186-4, section C.3.1. typedef struct { // w1 is w-1. BIGNUM *w1; // m is (w-1)/2^a. BIGNUM *m; // one_mont is 1 (mod w) in Montgomery form. BIGNUM *one_mont; // w1_mont is w-1 (mod w) in Montgomery form. BIGNUM *w1_mont; // w_bits is BN_num_bits(w). int w_bits; // a is the largest integer such that 2^a divides w-1. int a; } BN_MILLER_RABIN; // bn_miller_rabin_init initializes |miller_rabin| for testing if |mont->N| is // prime. It returns one on success and zero on error. OPENSSL_EXPORT int bn_miller_rabin_init(BN_MILLER_RABIN *miller_rabin, const BN_MONT_CTX *mont, BN_CTX *ctx); // bn_miller_rabin_iteration performs one Miller-Rabin iteration, checking if // |b| is a composite witness for |mont->N|. |miller_rabin| must have been // initialized with |bn_miller_rabin_setup|. On success, it returns one and sets // |*out_is_possibly_prime| to one if |mont->N| may still be prime or zero if // |b| shows it is composite. On allocation or internal failure, it returns // zero. OPENSSL_EXPORT int bn_miller_rabin_iteration( const BN_MILLER_RABIN *miller_rabin, int *out_is_possibly_prime, const BIGNUM *b, const BN_MONT_CTX *mont, BN_CTX *ctx); // bn_rshift1_words sets |r| to |a| >> 1, where both arrays are |num| bits wide. void bn_rshift1_words(BN_ULONG *r, const BN_ULONG *a, size_t num); // bn_rshift_words sets |r| to |a| >> |shift|, where both arrays are |num| bits // wide. void bn_rshift_words(BN_ULONG *r, const BN_ULONG *a, unsigned shift, size_t num); // bn_rshift_secret_shift behaves like |BN_rshift| but runs in time independent // of both |a| and |n|. OPENSSL_EXPORT int bn_rshift_secret_shift(BIGNUM *r, const BIGNUM *a, unsigned n, BN_CTX *ctx); // bn_reduce_once sets |r| to |a| mod |m| where 0 <= |a| < 2*|m|. It returns // zero if |a| < |m| and a mask of all ones if |a| >= |m|. Each array is |num| // words long, but |a| has an additional word specified by |carry|. |carry| must // be zero or one, as implied by the bounds on |a|. // // |r|, |a|, and |m| may not alias. Use |bn_reduce_once_in_place| if |r| and |a| // must alias. BN_ULONG bn_reduce_once(BN_ULONG *r, const BN_ULONG *a, BN_ULONG carry, const BN_ULONG *m, size_t num); // bn_reduce_once_in_place behaves like |bn_reduce_once| but acts in-place on // |r|, using |tmp| as scratch space. |r|, |tmp|, and |m| may not alias. BN_ULONG bn_reduce_once_in_place(BN_ULONG *r, BN_ULONG carry, const BN_ULONG *m, BN_ULONG *tmp, size_t num); // Constant-time non-modular arithmetic. // // The following functions implement non-modular arithmetic in constant-time // and pessimally set |r->width| to the largest possible word size. // // Note this means that, e.g., repeatedly multiplying by one will cause widths // to increase without bound. The corresponding public API functions minimize // their outputs to avoid regressing calculator consumers. // bn_uadd_consttime behaves like |BN_uadd|, but it pessimally sets // |r->width| = |a->width| + |b->width| + 1. int bn_uadd_consttime(BIGNUM *r, const BIGNUM *a, const BIGNUM *b); // bn_usub_consttime behaves like |BN_usub|, but it pessimally sets // |r->width| = |a->width|. int bn_usub_consttime(BIGNUM *r, const BIGNUM *a, const BIGNUM *b); // bn_abs_sub_consttime sets |r| to the absolute value of |a| - |b|, treating // both inputs as secret. It returns one on success and zero on error. OPENSSL_EXPORT int bn_abs_sub_consttime(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx); // bn_mul_consttime behaves like |BN_mul|, but it rejects negative inputs and // pessimally sets |r->width| to |a->width| + |b->width|, to avoid leaking // information about |a| and |b|. int bn_mul_consttime(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx); // bn_sqrt_consttime behaves like |BN_sqrt|, but it pessimally sets |r->width| // to 2*|a->width|, to avoid leaking information about |a| and |b|. int bn_sqr_consttime(BIGNUM *r, const BIGNUM *a, BN_CTX *ctx); // bn_div_consttime behaves like |BN_div|, but it rejects negative inputs and // treats both inputs, including their magnitudes, as secret. It is, as a // result, much slower than |BN_div| and should only be used for rare operations // where Montgomery reduction is not available. |divisor_min_bits| is a // public lower bound for |BN_num_bits(divisor)|. When |divisor|'s bit width is // public, this can speed up the operation. // // Note that |quotient->width| will be set pessimally to |numerator->width|. OPENSSL_EXPORT int bn_div_consttime(BIGNUM *quotient, BIGNUM *remainder, const BIGNUM *numerator, const BIGNUM *divisor, unsigned divisor_min_bits, BN_CTX *ctx); // bn_is_relatively_prime checks whether GCD(|x|, |y|) is one. On success, it // returns one and sets |*out_relatively_prime| to one if the GCD was one and // zero otherwise. On error, it returns zero. OPENSSL_EXPORT int bn_is_relatively_prime(int *out_relatively_prime, const BIGNUM *x, const BIGNUM *y, BN_CTX *ctx); // bn_lcm_consttime sets |r| to LCM(|a|, |b|). It returns one and success and // zero on error. |a| and |b| are both treated as secret. OPENSSL_EXPORT int bn_lcm_consttime(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx); // bn_mont_ctx_init zero-initialies |mont|. void bn_mont_ctx_init(BN_MONT_CTX *mont); // bn_mont_ctx_cleanup releases memory associated with |mont|, without freeing // |mont| itself. void bn_mont_ctx_cleanup(BN_MONT_CTX *mont); // Constant-time modular arithmetic. // // The following functions implement basic constant-time modular arithmetic. // bn_mod_add_words sets |r| to |a| + |b| (mod |m|), using |tmp| as scratch // space. Each array is |num| words long. |a| and |b| must be < |m|. Any pair of // |r|, |a|, and |b| may alias. void bn_mod_add_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b, const BN_ULONG *m, BN_ULONG *tmp, size_t num); // bn_mod_add_consttime acts like |BN_mod_add_quick| but takes a |BN_CTX|. int bn_mod_add_consttime(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m, BN_CTX *ctx); // bn_mod_sub_words sets |r| to |a| - |b| (mod |m|), using |tmp| as scratch // space. Each array is |num| words long. |a| and |b| must be < |m|. Any pair of // |r|, |a|, and |b| may alias. void bn_mod_sub_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b, const BN_ULONG *m, BN_ULONG *tmp, size_t num); // bn_mod_sub_consttime acts like |BN_mod_sub_quick| but takes a |BN_CTX|. int bn_mod_sub_consttime(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m, BN_CTX *ctx); // bn_mod_lshift1_consttime acts like |BN_mod_lshift1_quick| but takes a // |BN_CTX|. int bn_mod_lshift1_consttime(BIGNUM *r, const BIGNUM *a, const BIGNUM *m, BN_CTX *ctx); // bn_mod_lshift_consttime acts like |BN_mod_lshift_quick| but takes a |BN_CTX|. int bn_mod_lshift_consttime(BIGNUM *r, const BIGNUM *a, int n, const BIGNUM *m, BN_CTX *ctx); // bn_mod_inverse_consttime sets |r| to |a|^-1, mod |n|. |a| must be non- // negative and less than |n|. It returns one on success and zero on error. On // failure, if the failure was caused by |a| having no inverse mod |n| then // |*out_no_inverse| will be set to one; otherwise it will be set to zero. // // This function treats both |a| and |n| as secret, provided they are both non- // zero and the inverse exists. It should only be used for even moduli where // none of the less general implementations are applicable. OPENSSL_EXPORT int bn_mod_inverse_consttime(BIGNUM *r, int *out_no_inverse, const BIGNUM *a, const BIGNUM *n, BN_CTX *ctx); // bn_mod_inverse_prime sets |out| to the modular inverse of |a| modulo |p|, // computed with Fermat's Little Theorem. It returns one on success and zero on // error. If |mont_p| is NULL, one will be computed temporarily. int bn_mod_inverse_prime(BIGNUM *out, const BIGNUM *a, const BIGNUM *p, BN_CTX *ctx, const BN_MONT_CTX *mont_p); // bn_mod_inverse_secret_prime behaves like |bn_mod_inverse_prime| but uses // |BN_mod_exp_mont_consttime| instead of |BN_mod_exp_mont| in hopes of // protecting the exponent. int bn_mod_inverse_secret_prime(BIGNUM *out, const BIGNUM *a, const BIGNUM *p, BN_CTX *ctx, const BN_MONT_CTX *mont_p); // BN_MONT_CTX_set_locked takes |lock| and checks whether |*pmont| is NULL. If // so, it creates a new |BN_MONT_CTX| and sets the modulus for it to |mod|. It // then stores it as |*pmont|. It returns one on success and zero on error. Note // this function assumes |mod| is public. // // If |*pmont| is already non-NULL then it does nothing and returns one. int BN_MONT_CTX_set_locked(BN_MONT_CTX **pmont, CRYPTO_MUTEX *lock, const BIGNUM *mod, BN_CTX *bn_ctx); // Low-level operations for small numbers. // // The following functions implement algorithms suitable for use with scalars // and field elements in elliptic curves. They rely on the number being small // both to stack-allocate various temporaries and because they do not implement // optimizations useful for the larger values used in RSA. // BN_SMALL_MAX_WORDS is the largest size input these functions handle. This // limit allows temporaries to be more easily stack-allocated. This limit is set // to accommodate P-521. #if defined(OPENSSL_32_BIT) #define BN_SMALL_MAX_WORDS 17 #else #define BN_SMALL_MAX_WORDS 9 #endif // bn_mul_small sets |r| to |a|*|b|. |num_r| must be |num_a| + |num_b|. |r| may // not alias with |a| or |b|. void bn_mul_small(BN_ULONG *r, size_t num_r, const BN_ULONG *a, size_t num_a, const BN_ULONG *b, size_t num_b); // bn_sqr_small sets |r| to |a|^2. |num_a| must be at most |BN_SMALL_MAX_WORDS|. // |num_r| must be |num_a|*2. |r| and |a| may not alias. void bn_sqr_small(BN_ULONG *r, size_t num_r, const BN_ULONG *a, size_t num_a); // In the following functions, the modulus must be at most |BN_SMALL_MAX_WORDS| // words long. // bn_to_montgomery_small sets |r| to |a| translated to the Montgomery domain. // |r| and |a| are |num| words long, which must be |mont->N.width|. |a| must be // fully reduced and may alias |r|. void bn_to_montgomery_small(BN_ULONG *r, const BN_ULONG *a, size_t num, const BN_MONT_CTX *mont); // bn_from_montgomery_small sets |r| to |a| translated out of the Montgomery // domain. |r| and |a| are |num_r| and |num_a| words long, respectively. |num_r| // must be |mont->N.width|. |a| must be at most |mont->N|^2 and may alias |r|. // // Unlike most of these functions, only |num_r| is bounded by // |BN_SMALL_MAX_WORDS|. |num_a| may exceed it, but must be at most 2 * |num_r|. void bn_from_montgomery_small(BN_ULONG *r, size_t num_r, const BN_ULONG *a, size_t num_a, const BN_MONT_CTX *mont); // bn_mod_mul_montgomery_small sets |r| to |a| * |b| mod |mont->N|. Both inputs // and outputs are in the Montgomery domain. Each array is |num| words long, // which must be |mont->N.width|. Any two of |r|, |a|, and |b| may alias. |a| // and |b| must be reduced on input. void bn_mod_mul_montgomery_small(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b, size_t num, const BN_MONT_CTX *mont); // bn_mod_exp_mont_small sets |r| to |a|^|p| mod |mont->N|. It returns one on // success and zero on programmer or internal error. Both inputs and outputs are // in the Montgomery domain. |r| and |a| are |num| words long, which must be // |mont->N.width| and at most |BN_SMALL_MAX_WORDS|. |num_p|, measured in bits, // must fit in |size_t|. |a| must be fully-reduced. This function runs in time // independent of |a|, but |p| and |mont->N| are public values. |a| must be // fully-reduced and may alias with |r|. // // Note this function differs from |BN_mod_exp_mont| which uses Montgomery // reduction but takes input and output outside the Montgomery domain. Combine // this function with |bn_from_montgomery_small| and |bn_to_montgomery_small| // if necessary. void bn_mod_exp_mont_small(BN_ULONG *r, const BN_ULONG *a, size_t num, const BN_ULONG *p, size_t num_p, const BN_MONT_CTX *mont); // bn_mod_inverse0_prime_mont_small sets |r| to |a|^-1 mod |mont->N|. If |a| is // zero, |r| is set to zero. |mont->N| must be a prime. |r| and |a| are |num| // words long, which must be |mont->N.width| and at most |BN_SMALL_MAX_WORDS|. // |a| must be fully-reduced and may alias |r|. This function runs in time // independent of |a|, but |mont->N| is a public value. void bn_mod_inverse0_prime_mont_small(BN_ULONG *r, const BN_ULONG *a, size_t num, const BN_MONT_CTX *mont); // Word-based byte conversion functions. // bn_big_endian_to_words interprets |in_len| bytes from |in| as a big-endian, // unsigned integer and writes the result to |out_len| words in |out|. |out_len| // must be large enough to represent any |in_len|-byte value. That is, |out_len| // must be at least |BN_BYTES * in_len|. void bn_big_endian_to_words(BN_ULONG *out, size_t out_len, const uint8_t *in, size_t in_len); // bn_words_to_big_endian represents |in_len| words from |in| as a big-endian, // unsigned integer in |out_len| bytes. It writes the result to |out|. |out_len| // must be large enough to represent |in| without truncation. // // Note |out_len| may be less than |BN_BYTES * in_len| if |in| is known to have // leading zeros. void bn_words_to_big_endian(uint8_t *out, size_t out_len, const BN_ULONG *in, size_t in_len); #if defined(__cplusplus) } // extern C #endif #endif // OPENSSL_HEADER_BN_INTERNAL_H