gnutls_dh_set_prime_bits — API function


#include <gnutls/gnutls.h>
void gnutls_dh_set_prime_bits( gnutls_session_t session,
  unsigned int bits);


gnutls_session_t session

is a gnutls_session_t structure.

unsigned int bits

is the number of bits


This function sets the number of bits, for use in a Diffie−Hellman key exchange. This is used both in DH ephemeral and DH anonymous cipher suites. This will set the minimum size of the prime that will be used for the handshake.

In the client side it sets the minimum accepted number of bits. If a server sends a prime with less bits than that GNUTLS_E_DH_PRIME_UNACCEPTABLE will be returned by the handshake.

Note that values lower than 512 bits may allow decryption of the exchanged data.

The function has no effect in server side.

Note that since 3.1.7 this function is deprecated. The minimum number of bits is set by the priority string level. Also this function must be called after gnutls_priority_set_direct() or the set value may be overridden by the selected priority options.


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The full documentation for gnutls is maintained as a Texinfo manual. If the info and gnutls programs are properly installed at your site, the command

info gnutls

should give you access to the complete manual. As an alternative you may obtain the manual from:


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