1BN_BLINDING_new(3)                  OpenSSL                 BN_BLINDING_new(3)
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3
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NAME

6       BN_BLINDING_new, BN_BLINDING_free, BN_BLINDING_update, BN_BLINDING_con‐
7       vert, BN_BLINDING_invert, BN_BLINDING_convert_ex, BN_BLIND‐
8       ING_invert_ex, BN_BLINDING_get_thread_id, BN_BLINDING_set_thread_id,
9       BN_BLINDING_get_flags, BN_BLINDING_set_flags, BN_BLINDING_create_param
10       - blinding related BIGNUM functions.
11

SYNOPSIS

13        #include <openssl/bn.h>
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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        unsigned long BN_BLINDING_get_thread_id(const BN_BLINDING *);
26        void BN_BLINDING_set_thread_id(BN_BLINDING *, unsigned long);
27        unsigned long BN_BLINDING_get_flags(const BN_BLINDING *);
28        void BN_BLINDING_set_flags(BN_BLINDING *, unsigned long);
29        BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b,
30               const BIGNUM *e, BIGNUM *m, BN_CTX *ctx,
31               int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
32                                 const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx),
33               BN_MONT_CTX *m_ctx);
34

DESCRIPTION

36       BN_BLINDING_new() allocates a new BN_BLINDING structure and copies the
37       A and Ai values into the newly created BN_BLINDING object.
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39       BN_BLINDING_free() frees the BN_BLINDING structure.
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41       BN_BLINDING_update() updates the BN_BLINDING parameters by squaring the
42       A and Ai or, after specific number of uses and if the necessary parame‐
43       ters are set, by re-creating the blinding parameters.
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45       BN_BLINDING_convert_ex() multiplies n with the blinding factor A.  If r
46       is not NULL a copy the inverse blinding factor Ai will be returned in r
47       (this is useful if a RSA object is shared amoung several threads).
48       BN_BLINDING_invert_ex() multiplies n with the inverse blinding factor
49       Ai. If r is not NULL it will be used as the inverse blinding.
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51       BN_BLINDING_convert() and BN_BLINDING_invert() are wrapper functions
52       for BN_BLINDING_convert_ex() and BN_BLINDING_invert_ex() with r set to
53       NULL.
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55       BN_BLINDING_set_thread_id() and BN_BLINDING_get_thread_id() set and get
56       the "thread id" value of the BN_BLINDING structure, a field provided to
57       users of BN_BLINDING structure to help them provide proper locking if
58       needed for multi-threaded use. The "thread id" of a newly allocated
59       BN_BLINDING structure is zero.
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61       BN_BLINDING_get_flags() returns the BN_BLINDING flags. Currently there
62       are two supported flags: BN_BLINDING_NO_UPDATE and BN_BLIND‐
63       ING_NO_RECREATE. BN_BLINDING_NO_UPDATE inhibits the automatic update of
64       the BN_BLINDING parameters after each use and BN_BLINDING_NO_RECREATE
65       inhibits the automatic re-creation of the BN_BLINDING parameters after
66       a fixed number of uses (currently 32). In newly allocated BN_BLINDING
67       objects no flags are set.  BN_BLINDING_set_flags() sets the BN_BLINDING
68       parameters flags.
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70       BN_BLINDING_create_param() creates new BN_BLINDING parameters using the
71       exponent e and the modulus m. bn_mod_exp and m_ctx can be used to pass
72       special functions for exponentiation (normally BN_mod_exp_mont() and
73       BN_MONT_CTX).
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RETURN VALUES

76       BN_BLINDING_new() returns the newly allocated BN_BLINDING structure or
77       NULL in case of an error.
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79       BN_BLINDING_update(), BN_BLINDING_convert(), BN_BLINDING_invert(),
80       BN_BLINDING_convert_ex() and BN_BLINDING_invert_ex() return 1 on suc‐
81       cess and 0 if an error occured.
82
83       BN_BLINDING_get_thread_id() returns the thread id (a unsigned long
84       value) or 0 if not set.
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86       BN_BLINDING_get_flags() returns the currently set BN_BLINDING flags (a
87       unsigned long value).
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89       BN_BLINDING_create_param() returns the newly created BN_BLINDING param‐
90       eters or NULL on error.
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SEE ALSO

93       bn(3)
94

HISTORY

96       BN_BLINDING_convert_ex, BN_BLINDIND_invert_ex, BN_BLIND‐
97       ING_get_thread_id, BN_BLINDING_set_thread_id, BN_BLINDING_set_flags,
98       BN_BLINDING_get_flags and BN_BLINDING_create_param were first intro‐
99       duced in OpenSSL 0.9.8
100

AUTHOR

102       Nils Larsch for the OpenSSL project (http://www.openssl.org).
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1060.9.8b                            2005-04-26                BN_BLINDING_new(3)