X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fec%2Fecp_nistp256.c;h=8f3063563c31e8345eadbcb3eb5698ab88f50f4f;hp=119be01be099424411233157db5f5a6556bca3a5;hb=207a56437916a715bcf6e299c868c75a17ad8fc0;hpb=a836f9fa951e33a5186e2421413de0b50ed2233a diff --git a/crypto/ec/ecp_nistp256.c b/crypto/ec/ecp_nistp256.c index 119be01be0..8f3063563c 100644 --- a/crypto/ec/ecp_nistp256.c +++ b/crypto/ec/ecp_nistp256.c @@ -1,5 +1,5 @@ /* - * Copyright 2011-2016 The OpenSSL Project Authors. All Rights Reserved. + * Copyright 2011-2019 The OpenSSL Project Authors. All Rights Reserved. * * Licensed under the OpenSSL license (the "License"). You may not use * this file except in compliance with the License. You can obtain a copy @@ -53,7 +53,6 @@ typedef __int128_t int128_t; typedef uint8_t u8; typedef uint32_t u32; typedef uint64_t u64; -typedef int64_t s64; /* * The underlying field. P256 operates over GF(2^256-2^224+2^192+2^96-1). We @@ -147,34 +146,21 @@ static void smallfelem_to_bin32(u8 out[32], const smallfelem in) *((u64 *)&out[24]) = in[3]; } -/* To preserve endianness when using BN_bn2bin and BN_bin2bn */ -static void flip_endian(u8 *out, const u8 *in, unsigned len) -{ - unsigned i; - for (i = 0; i < len; ++i) - out[i] = in[len - 1 - i]; -} - /* BN_to_felem converts an OpenSSL BIGNUM into an felem */ static int BN_to_felem(felem out, const BIGNUM *bn) { - felem_bytearray b_in; felem_bytearray b_out; - unsigned num_bytes; + int num_bytes; - /* BN_bn2bin eats leading zeroes */ - memset(b_out, 0, sizeof(b_out)); - num_bytes = BN_num_bytes(bn); - if (num_bytes > sizeof(b_out)) { + if (BN_is_negative(bn)) { ECerr(EC_F_BN_TO_FELEM, EC_R_BIGNUM_OUT_OF_RANGE); return 0; } - if (BN_is_negative(bn)) { + num_bytes = BN_bn2lebinpad(bn, b_out, sizeof(b_out)); + if (num_bytes < 0) { ECerr(EC_F_BN_TO_FELEM, EC_R_BIGNUM_OUT_OF_RANGE); return 0; } - num_bytes = BN_bn2bin(bn, b_in); - flip_endian(b_out, b_in, num_bytes); bin32_to_felem(out, b_out); return 1; } @@ -182,10 +168,9 @@ static int BN_to_felem(felem out, const BIGNUM *bn) /* felem_to_BN converts an felem into an OpenSSL BIGNUM */ static BIGNUM *smallfelem_to_BN(BIGNUM *out, const smallfelem in) { - felem_bytearray b_in, b_out; - smallfelem_to_bin32(b_in, in); - flip_endian(b_out, b_in, sizeof(b_out)); - return BN_bin2bn(b_out, sizeof(b_out), out); + felem_bytearray b_out; + smallfelem_to_bin32(b_out, in); + return BN_lebin2bn(b_out, sizeof(b_out), out); } /*- @@ -394,7 +379,7 @@ static void felem_shrink(smallfelem out, const felem in) { felem tmp; u64 a, b, mask; - s64 high, low; + u64 high, low; static const u64 kPrime3Test = 0x7fffffff00000001ul; /* 2^63 - 2^32 + 1 */ /* Carry 2->3 */ @@ -435,29 +420,31 @@ static void felem_shrink(smallfelem out, const felem in) * In order to make space in tmp[3] for the carry from 2 -> 3, we * conditionally subtract kPrime if tmp[3] is large enough. */ - high = tmp[3] >> 64; + high = (u64)(tmp[3] >> 64); /* As tmp[3] < 2^65, high is either 1 or 0 */ - high <<= 63; - high >>= 63; + high = 0 - high; /*- * high is: * all ones if the high word of tmp[3] is 1 - * all zeros if the high word of tmp[3] if 0 */ - low = tmp[3]; - mask = low >> 63; + * all zeros if the high word of tmp[3] if 0 + */ + low = (u64)tmp[3]; + mask = 0 - (low >> 63); /*- * mask is: * all ones if the MSB of low is 1 - * all zeros if the MSB of low if 0 */ + * all zeros if the MSB of low if 0 + */ low &= bottom63bits; low -= kPrime3Test; /* if low was greater than kPrime3Test then the MSB is zero */ low = ~low; - low >>= 63; + low = 0 - (low >> 63); /*- * low is: * all ones if low was > kPrime3Test - * all zeros if low was <= kPrime3Test */ + * all zeros if low was <= kPrime3Test + */ mask = (mask & low) | high; tmp[0] -= mask & kPrime[0]; tmp[1] -= mask & kPrime[1]; @@ -891,7 +878,7 @@ static void felem_contract(smallfelem out, const felem in) equal &= equal << 4; equal &= equal << 2; equal &= equal << 1; - equal = ((s64) equal) >> 63; + equal = 0 - (equal >> 63); all_equal_so_far &= equal; } @@ -958,7 +945,7 @@ static limb smallfelem_is_zero(const smallfelem small) is_zero &= is_zero << 4; is_zero &= is_zero << 2; is_zero &= is_zero << 1; - is_zero = ((s64) is_zero) >> 63; + is_zero = 0 - (is_zero >> 63); is_p = (small[0] ^ kPrime[0]) | (small[1] ^ kPrime[1]) | @@ -970,7 +957,7 @@ static limb smallfelem_is_zero(const smallfelem small) is_p &= is_p << 4; is_p &= is_p << 2; is_p &= is_p << 1; - is_p = ((s64) is_p) >> 63; + is_p = 0 - (is_p >> 63); is_zero |= is_p; @@ -1809,6 +1796,7 @@ const EC_METHOD *EC_GFp_nistp256_method(void) ec_GFp_nist_field_mul, ec_GFp_nist_field_sqr, 0 /* field_div */ , + ec_GFp_simple_field_inv, 0 /* field_encode */ , 0 /* field_decode */ , 0, /* field_set_to_one */ @@ -2017,8 +2005,8 @@ int ec_GFp_nistp256_points_mul(const EC_GROUP *group, EC_POINT *r, felem_bytearray *secrets = NULL; smallfelem (*pre_comp)[17][3] = NULL; smallfelem *tmp_smallfelems = NULL; - felem_bytearray tmp; - unsigned i, num_bytes; + unsigned i; + int num_bytes; int have_pre_comp = 0; size_t num_points = num; smallfelem x_in, y_in, z_in; @@ -2097,17 +2085,15 @@ int ec_GFp_nistp256_points_mul(const EC_GROUP *group, EC_POINT *r, memset(secrets, 0, sizeof(*secrets) * num_points); memset(pre_comp, 0, sizeof(*pre_comp) * num_points); for (i = 0; i < num_points; ++i) { - if (i == num) + if (i == num) { /* * we didn't have a valid precomputation, so we pick the * generator */ - { p = EC_GROUP_get0_generator(group); p_scalar = scalar; - } else + } else { /* the i^th point */ - { p = points[i]; p_scalar = scalars[i]; } @@ -2123,10 +2109,16 @@ int ec_GFp_nistp256_points_mul(const EC_GROUP *group, EC_POINT *r, ECerr(EC_F_EC_GFP_NISTP256_POINTS_MUL, ERR_R_BN_LIB); goto err; } - num_bytes = BN_bn2bin(tmp_scalar, tmp); - } else - num_bytes = BN_bn2bin(p_scalar, tmp); - flip_endian(secrets[i], tmp, num_bytes); + num_bytes = BN_bn2lebinpad(tmp_scalar, + secrets[i], sizeof(secrets[i])); + } else { + num_bytes = BN_bn2lebinpad(p_scalar, + secrets[i], sizeof(secrets[i])); + } + if (num_bytes < 0) { + ECerr(EC_F_EC_GFP_NISTP256_POINTS_MUL, ERR_R_BN_LIB); + goto err; + } /* precompute multiples */ if ((!BN_to_felem(x_out, p->X)) || (!BN_to_felem(y_out, p->Y)) || @@ -2171,20 +2163,21 @@ int ec_GFp_nistp256_points_mul(const EC_GROUP *group, EC_POINT *r, ECerr(EC_F_EC_GFP_NISTP256_POINTS_MUL, ERR_R_BN_LIB); goto err; } - num_bytes = BN_bn2bin(tmp_scalar, tmp); - } else - num_bytes = BN_bn2bin(scalar, tmp); - flip_endian(g_secret, tmp, num_bytes); + num_bytes = BN_bn2lebinpad(tmp_scalar, g_secret, sizeof(g_secret)); + } else { + num_bytes = BN_bn2lebinpad(scalar, g_secret, sizeof(g_secret)); + } /* do the multiplication with generator precomputation */ batch_mul(x_out, y_out, z_out, (const felem_bytearray(*))secrets, num_points, g_secret, mixed, (const smallfelem(*)[17][3])pre_comp, g_pre_comp); - } else + } else { /* do the multiplication without generator precomputation */ batch_mul(x_out, y_out, z_out, (const felem_bytearray(*))secrets, num_points, NULL, mixed, (const smallfelem(*)[17][3])pre_comp, NULL); + } /* reduce the output to its unique minimal representation */ felem_contract(x_in, x_out); felem_contract(y_in, y_out);