diff options
Diffstat (limited to 'crypto/bn/bn_local.h')
| -rw-r--r-- | crypto/bn/bn_local.h | 36 |
1 files changed, 35 insertions, 1 deletions
diff --git a/crypto/bn/bn_local.h b/crypto/bn/bn_local.h index 8ad69ccd3639..30b7614fdbb2 100644 --- a/crypto/bn/bn_local.h +++ b/crypto/bn/bn_local.h @@ -1,5 +1,5 @@ /* - * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved. + * Copyright 1995-2023 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 @@ -35,6 +35,26 @@ /* #define BN_DEBUG */ /* #define BN_DEBUG_RAND */ +/* + * This should limit the stack usage due to alloca to about 4K. + * BN_SOFT_LIMIT is a soft limit equivalent to 2*OPENSSL_RSA_MAX_MODULUS_BITS. + * Beyond that size bn_mul_mont is no longer used, and the constant time + * assembler code is disabled, due to the blatant alloca and bn_mul_mont usage. + * Note that bn_mul_mont does an alloca that is hidden away in assembly. + * It is not recommended to do computations with numbers exceeding this limit, + * since the result will be highly version dependent: + * While the current OpenSSL version will use non-optimized, but safe code, + * previous versions will use optimized code, that may crash due to unexpected + * stack overflow, and future versions may very well turn this into a hard + * limit. + * Note however, that it is possible to override the size limit using + * "./config -DBN_SOFT_LIMIT=<limit>" if necessary, and the O/S specific + * stack limit is known and taken into consideration. + */ +# ifndef BN_SOFT_LIMIT +# define BN_SOFT_LIMIT (4096 / BN_BYTES) +# endif + # ifndef OPENSSL_SMALL_FOOTPRINT # define BN_MUL_COMBA # define BN_SQR_COMBA @@ -263,6 +283,20 @@ struct bn_gencb_st { } cb; }; +struct bn_blinding_st { + BIGNUM *A; + BIGNUM *Ai; + BIGNUM *e; + BIGNUM *mod; /* just a reference */ + CRYPTO_THREAD_ID tid; + int counter; + unsigned long flags; + BN_MONT_CTX *m_ctx; + int (*bn_mod_exp) (BIGNUM *r, const BIGNUM *a, const BIGNUM *p, + const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx); + CRYPTO_RWLOCK *lock; +}; + /*- * BN_window_bits_for_exponent_size -- macro for sliding window mod_exp functions * |