openssl1.0/doc/crypto/BN_BLINDING_new.pod
2019-08-09 10:00:55 +02:00

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=pod
=head1 NAME
BN_BLINDING_new, BN_BLINDING_free, BN_BLINDING_update, BN_BLINDING_convert,
BN_BLINDING_invert, BN_BLINDING_convert_ex, BN_BLINDING_invert_ex,
BN_BLINDING_get_thread_id, BN_BLINDING_set_thread_id, BN_BLINDING_thread_id, BN_BLINDING_get_flags,
BN_BLINDING_set_flags, BN_BLINDING_create_param - blinding related BIGNUM
functions.
=head1 SYNOPSIS
#include <openssl/bn.h>
BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai,
BIGNUM *mod);
void BN_BLINDING_free(BN_BLINDING *b);
int BN_BLINDING_update(BN_BLINDING *b,BN_CTX *ctx);
int BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx);
int BN_BLINDING_invert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx);
int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b,
BN_CTX *ctx);
int BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b,
BN_CTX *ctx);
#ifndef OPENSSL_NO_DEPRECATED
unsigned long BN_BLINDING_get_thread_id(const BN_BLINDING *);
void BN_BLINDING_set_thread_id(BN_BLINDING *, unsigned long);
#endif
CRYPTO_THREADID *BN_BLINDING_thread_id(BN_BLINDING *);
unsigned long BN_BLINDING_get_flags(const BN_BLINDING *);
void BN_BLINDING_set_flags(BN_BLINDING *, unsigned long);
BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b,
const BIGNUM *e, BIGNUM *m, BN_CTX *ctx,
int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx),
BN_MONT_CTX *m_ctx);
=head1 DESCRIPTION
BN_BLINDING_new() allocates a new B<BN_BLINDING> structure and copies
the B<A> and B<Ai> values into the newly created B<BN_BLINDING> object.
BN_BLINDING_free() frees the B<BN_BLINDING> structure.
BN_BLINDING_update() updates the B<BN_BLINDING> parameters by squaring
the B<A> and B<Ai> or, after specific number of uses and if the
necessary parameters are set, by re-creating the blinding parameters.
BN_BLINDING_convert_ex() multiplies B<n> with the blinding factor B<A>.
If B<r> is not NULL a copy the inverse blinding factor B<Ai> will be
returned in B<r> (this is useful if a B<RSA> object is shared among
several threads). BN_BLINDING_invert_ex() multiplies B<n> with the
inverse blinding factor B<Ai>. If B<r> is not NULL it will be used as
the inverse blinding.
BN_BLINDING_convert() and BN_BLINDING_invert() are wrapper
functions for BN_BLINDING_convert_ex() and BN_BLINDING_invert_ex()
with B<r> set to NULL.
BN_BLINDING_thread_id() provides access to the B<CRYPTO_THREADID>
object within the B<BN_BLINDING> structure. This is to help users
provide proper locking if needed for multi-threaded use. The "thread
id" object of a newly allocated B<BN_BLINDING> structure is
initialised to the thread id in which BN_BLINDING_new() was called.
BN_BLINDING_get_flags() returns the BN_BLINDING flags. Currently
there are two supported flags: B<BN_BLINDING_NO_UPDATE> and
B<BN_BLINDING_NO_RECREATE>. B<BN_BLINDING_NO_UPDATE> inhibits the
automatic update of the B<BN_BLINDING> parameters after each use
and B<BN_BLINDING_NO_RECREATE> inhibits the automatic re-creation
of the B<BN_BLINDING> parameters after a fixed number of uses (currently
32). In newly allocated B<BN_BLINDING> objects no flags are set.
BN_BLINDING_set_flags() sets the B<BN_BLINDING> parameters flags.
BN_BLINDING_create_param() creates new B<BN_BLINDING> parameters
using the exponent B<e> and the modulus B<m>. B<bn_mod_exp> and
B<m_ctx> can be used to pass special functions for exponentiation
(normally BN_mod_exp_mont() and B<BN_MONT_CTX>).
=head1 RETURN VALUES
BN_BLINDING_new() returns the newly allocated B<BN_BLINDING> structure
or NULL in case of an error.
BN_BLINDING_update(), BN_BLINDING_convert(), BN_BLINDING_invert(),
BN_BLINDING_convert_ex() and BN_BLINDING_invert_ex() return 1 on
success and 0 if an error occurred.
BN_BLINDING_thread_id() returns a pointer to the thread id object
within a B<BN_BLINDING> object.
BN_BLINDING_get_flags() returns the currently set B<BN_BLINDING> flags
(a B<unsigned long> value).
BN_BLINDING_create_param() returns the newly created B<BN_BLINDING>
parameters or NULL on error.
=head1 SEE ALSO
L<bn(3)|bn(3)>
=head1 HISTORY
BN_BLINDING_thread_id was first introduced in OpenSSL 1.0.0, and it
deprecates BN_BLINDING_set_thread_id and BN_BLINDING_get_thread_id.
BN_BLINDING_convert_ex, BN_BLINDIND_invert_ex, BN_BLINDING_get_thread_id,
BN_BLINDING_set_thread_id, BN_BLINDING_set_flags, BN_BLINDING_get_flags
and BN_BLINDING_create_param were first introduced in OpenSSL 0.9.8
=head1 AUTHOR
Nils Larsch for the OpenSSL project (http://www.openssl.org).
=cut