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78 lines
2.5 KiB
78 lines
2.5 KiB
=pod |
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=head1 NAME |
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dh - Diffie-Hellman key agreement |
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=head1 SYNOPSIS |
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#include <openssl/dh.h> |
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#include <openssl/engine.h> |
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DH * DH_new(void); |
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void DH_free(DH *dh); |
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int DH_size(const DH *dh); |
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DH * DH_generate_parameters(int prime_len, int generator, |
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void (*callback)(int, int, void *), void *cb_arg); |
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int DH_check(const DH *dh, int *codes); |
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int DH_generate_key(DH *dh); |
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int DH_compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh); |
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void DH_set_default_method(const DH_METHOD *meth); |
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const DH_METHOD *DH_get_default_method(void); |
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int DH_set_method(DH *dh, const DH_METHOD *meth); |
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DH *DH_new_method(ENGINE *engine); |
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const DH_METHOD *DH_OpenSSL(void); |
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int DH_get_ex_new_index(long argl, char *argp, int (*new_func)(), |
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int (*dup_func)(), void (*free_func)()); |
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int DH_set_ex_data(DH *d, int idx, char *arg); |
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char *DH_get_ex_data(DH *d, int idx); |
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DH * d2i_DHparams(DH **a, unsigned char **pp, long length); |
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int i2d_DHparams(const DH *a, unsigned char **pp); |
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int DHparams_print_fp(FILE *fp, const DH *x); |
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int DHparams_print(BIO *bp, const DH *x); |
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=head1 DESCRIPTION |
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These functions implement the Diffie-Hellman key agreement protocol. |
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The generation of shared DH parameters is described in |
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L<DH_generate_parameters(3)|DH_generate_parameters(3)>; L<DH_generate_key(3)|DH_generate_key(3)> describes how |
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to perform a key agreement. |
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The B<DH> structure consists of several BIGNUM components. |
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struct |
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{ |
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BIGNUM *p; // prime number (shared) |
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BIGNUM *g; // generator of Z_p (shared) |
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BIGNUM *priv_key; // private DH value x |
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BIGNUM *pub_key; // public DH value g^x |
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// ... |
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}; |
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DH |
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Note that DH keys may use non-standard B<DH_METHOD> implementations, |
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either directly or by the use of B<ENGINE> modules. In some cases (eg. an |
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ENGINE providing support for hardware-embedded keys), these BIGNUM values |
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will not be used by the implementation or may be used for alternative data |
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storage. For this reason, applications should generally avoid using DH |
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structure elements directly and instead use API functions to query or |
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modify keys. |
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=head1 SEE ALSO |
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L<dhparam(1)|dhparam(1)>, L<bn(3)|bn(3)>, L<dsa(3)|dsa(3)>, L<err(3)|err(3)>, |
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L<rand(3)|rand(3)>, L<rsa(3)|rsa(3)>, L<engine(3)|engine(3)>, |
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L<DH_set_method(3)|DH_set_method(3)>, L<DH_new(3)|DH_new(3)>, |
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L<DH_get_ex_new_index(3)|DH_get_ex_new_index(3)>, |
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L<DH_generate_parameters(3)|DH_generate_parameters(3)>, |
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L<DH_compute_key(3)|DH_compute_key(3)>, L<d2i_DHparams(3)|d2i_DHparams(3)>, |
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L<RSA_print(3)|RSA_print(3)> |
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=cut
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