projects / thirdparty / openssl.git / blame
| Commit | Line | Data |
|---|---|---|
| 4486d0cd UM |
1 | =pod |
| 2 | ||
| 3 | =head1 NAME | |
| 4 | ||
| 5 | DH_set_default_method, DH_get_default_method, DH_set_method, | |
| 6 | DH_new_method, DH_OpenSSL - Select RSA method | |
| 7 | ||
| 8 | =head1 SYNOPSIS | |
| 9 | ||
| 10 | #include <openssl/dh.h> | |
| 11 | ||
| 12 | void DH_set_default_method(DH_METHOD *meth); | |
| 13 | ||
| 14 | DH_METHOD *DH_get_default_method(void); | |
| 15 | ||
| 16 | DH_METHOD *DH_set_method(DH *dh, DH_METHOD *meth); | |
| 17 | ||
| 18 | DH *DH_new_method(DH_METHOD *meth); | |
| 19 | ||
| 20 | DH_METHOD *DH_OpenSSL(void); | |
| 21 | ||
| 22 | =head1 DESCRIPTION | |
| 23 | ||
| 24 | A B<DH_METHOD> specifies the functions that OpenSSL uses for Diffie-Hellman | |
| 25 | operations. By modifying the method, alternative implementations | |
| 26 | such as hardware accelerators may be used. | |
| 27 | ||
| 28 | Initially, the default is to use the OpenSSL internal implementation. | |
| 29 | DH_OpenSSL() returns a pointer to that method. | |
| 30 | ||
| 31 | DH_set_default_method() makes B<meth> the default method for all B<DH> | |
| 32 | structures created later. | |
| 33 | ||
| 34 | DH_get_default_method() returns a pointer to the current default | |
| 35 | method. | |
| 36 | ||
| 37 | DH_set_method() selects B<meth> for all operations using the structure B<dh>. | |
| 38 | ||
| 39 | DH_get_method() returns a pointer to the method currently selected | |
| 40 | for B<dh>. | |
| 41 | ||
| 42 | DH_new_method() allocates and initializes a B<DH> structure so that | |
| 43 | B<method> will be used for the DH operations. If B<method> is B<NULL>, | |
| 44 | the default method is used. | |
| 45 | ||
| 46 | =head1 THE DH_METHOD STRUCTURE | |
| 47 | ||
| 48 | typedef struct dh_meth_st | |
| 49 | { | |
| 50 | /* name of the implementation */ | |
| 51 | const char *name; | |
| 52 | ||
| 53 | /* generate private and public DH values for key agreement */ | |
| 54 | int (*generate_key)(DH *dh); | |
| 55 | ||
| 56 | /* compute shared secret */ | |
| 57 | int (*compute_key)(unsigned char *key, BIGNUM *pub_key, DH *dh); | |
| 58 | ||
| 59 | /* compute r = a ^ p mod m. May be NULL */ | |
| 60 | int (*bn_mod_exp)(DH *dh, BIGNUM *r, BIGNUM *a, const BIGNUM *p, | |
| 61 | const BIGNUM *m, BN_CTX *ctx, | |
| 62 | BN_MONT_CTX *m_ctx); | |
| 63 | ||
| 64 | /* called at DH_new */ | |
| 65 | int (*init)(DH *dh); | |
| 66 | ||
| 67 | /* called at DH_free */ | |
| 68 | int (*finish)(DH *dh); | |
| 69 | ||
| 70 | int flags; | |
| 71 | ||
| 72 | char *app_data; /* ?? */ | |
| 73 | ||
| 74 | } DH_METHOD; | |
| 75 | ||
| 76 | =head1 RETURN VALUES | |
| 77 | ||
| 78 | DH_OpenSSL(), DH_get_default_method() and DH_get_method() return | |
| 79 | pointers to the respective B<DH_METHOD>s. | |
| 80 | ||
| 81 | DH_set_default_method() returns no value. | |
| 82 | ||
| 83 | DH_set_method() returns a pointer to the B<DH_METHOD> previously | |
| 84 | associated with B<dh>. | |
| 85 | ||
| 86 | DH_new_method() returns B<NULL> and sets an error code that can be | |
| 87 | obtained by ERR_get_error(3) if the allocation fails. Otherwise it | |
| 88 | returns a pointer to the newly allocated structure. | |
| 89 | ||
| 90 | =head1 SEE ALSO | |
| 91 | ||
| 92 | dh(3), DH_new(3) | |
| 93 | ||
| 94 | =head1 HISTORY | |
| 95 | ||
| 96 | DH_set_default_method(), DH_get_default_method(), DH_set_method(), | |
| 97 | DH_new_method() and DH_OpenSSL() were added in OpenSSL 0.9.4. | |
| 98 | ||
| 99 | =cut |