BN_BLINDING_new.pod revision 264331 
1=pod
2
3=head1 NAME
4
5BN_BLINDING_new, BN_BLINDING_free, BN_BLINDING_update, BN_BLINDING_convert, 
6BN_BLINDING_invert, BN_BLINDING_convert_ex, BN_BLINDING_invert_ex, 
7BN_BLINDING_get_thread_id, BN_BLINDING_set_thread_id, BN_BLINDING_get_flags,
8BN_BLINDING_set_flags, BN_BLINDING_create_param - blinding related BIGNUM
9functions.
10
11=head1 SYNOPSIS
12
13 #include <openssl/bn.h>
14
15 BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai,
16	BIGNUM *mod);
17 void BN_BLINDING_free(BN_BLINDING *b);
18 int BN_BLINDING_update(BN_BLINDING *b,BN_CTX *ctx);
19 int BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx);
20 int BN_BLINDING_invert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx);
21 int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b,
22	BN_CTX *ctx);
23 int BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b,
24	BN_CTX *ctx);
25 #ifndef OPENSSL_NO_DEPRECATED
26 unsigned long BN_BLINDING_get_thread_id(const BN_BLINDING *);
27 void BN_BLINDING_set_thread_id(BN_BLINDING *, unsigned long);
28 #endif
29 CRYPTO_THREADID *BN_BLINDING_thread_id(BN_BLINDING *);
30 unsigned long BN_BLINDING_get_flags(const BN_BLINDING *);
31 void BN_BLINDING_set_flags(BN_BLINDING *, unsigned long);
32 BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b,
33	const BIGNUM *e, BIGNUM *m, BN_CTX *ctx,
34	int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
35			  const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx),
36	BN_MONT_CTX *m_ctx);
37
38=head1 DESCRIPTION
39
40BN_BLINDING_new() allocates a new B<BN_BLINDING> structure and copies
41the B<A> and B<Ai> values into the newly created B<BN_BLINDING> object.
42
43BN_BLINDING_free() frees the B<BN_BLINDING> structure.
44
45BN_BLINDING_update() updates the B<BN_BLINDING> parameters by squaring
46the B<A> and B<Ai> or, after specific number of uses and if the
47necessary parameters are set, by re-creating the blinding parameters.
48
49BN_BLINDING_convert_ex() multiplies B<n> with the blinding factor B<A>.
50If B<r> is not NULL a copy the inverse blinding factor B<Ai> will be
51returned in B<r> (this is useful if a B<RSA> object is shared among
52several threads). BN_BLINDING_invert_ex() multiplies B<n> with the
53inverse blinding factor B<Ai>. If B<r> is not NULL it will be used as
54the inverse blinding.
55
56BN_BLINDING_convert() and BN_BLINDING_invert() are wrapper
57functions for BN_BLINDING_convert_ex() and BN_BLINDING_invert_ex()
58with B<r> set to NULL.
59
60BN_BLINDING_thread_id() provides access to the B<CRYPTO_THREADID>
61object within the B<BN_BLINDING> structure. This is to help users
62provide proper locking if needed for multi-threaded use. The "thread
63id" object of a newly allocated B<BN_BLINDING> structure is
64initialised to the thread id in which BN_BLINDING_new() was called.
65
66BN_BLINDING_get_flags() returns the BN_BLINDING flags. Currently
67there are two supported flags: B<BN_BLINDING_NO_UPDATE> and
68B<BN_BLINDING_NO_RECREATE>. B<BN_BLINDING_NO_UPDATE> inhibits the
69automatic update of the B<BN_BLINDING> parameters after each use
70and B<BN_BLINDING_NO_RECREATE> inhibits the automatic re-creation
71of the B<BN_BLINDING> parameters after a fixed number of uses (currently
7232). In newly allocated B<BN_BLINDING> objects no flags are set.
73BN_BLINDING_set_flags() sets the B<BN_BLINDING> parameters flags.
74
75BN_BLINDING_create_param() creates new B<BN_BLINDING> parameters
76using the exponent B<e> and the modulus B<m>. B<bn_mod_exp> and
77B<m_ctx> can be used to pass special functions for exponentiation
78(normally BN_mod_exp_mont() and B<BN_MONT_CTX>).
79
80=head1 RETURN VALUES
81
82BN_BLINDING_new() returns the newly allocated B<BN_BLINDING> structure
83or NULL in case of an error.
84
85BN_BLINDING_update(), BN_BLINDING_convert(), BN_BLINDING_invert(),
86BN_BLINDING_convert_ex() and BN_BLINDING_invert_ex() return 1 on
87success and 0 if an error occured.
88
89BN_BLINDING_thread_id() returns a pointer to the thread id object
90within a B<BN_BLINDING> object.
91
92BN_BLINDING_get_flags() returns the currently set B<BN_BLINDING> flags
93(a B<unsigned long> value).
94
95BN_BLINDING_create_param() returns the newly created B<BN_BLINDING> 
96parameters or NULL on error.
97
98=head1 SEE ALSO
99
100L<bn(3)|bn(3)>
101
102=head1 HISTORY
103
104BN_BLINDING_thread_id was first introduced in OpenSSL 1.0.0, and it
105deprecates BN_BLINDING_set_thread_id and BN_BLINDING_get_thread_id.
106
107BN_BLINDING_convert_ex, BN_BLINDIND_invert_ex, BN_BLINDING_get_thread_id,
108BN_BLINDING_set_thread_id, BN_BLINDING_set_flags, BN_BLINDING_get_flags
109and BN_BLINDING_create_param were first introduced in OpenSSL 0.9.8
110
111=head1 AUTHOR
112
113Nils Larsch for the OpenSSL project (http://www.openssl.org).
114
115=cut
116