@deftypefun {int} {gnutls_x509_crt_get_pk_algorithm} (gnutls_x509_crt_t @var{cert}, unsigned int * @var{bits})
@var{cert}: should contain a @code{gnutls_x509_crt_t}  type

@var{bits}: if bits is non null it will hold the size of the parameters' in bits

This function will return the public key algorithm of an X.509
certificate.

If bits is non null, it should have enough size to hold the parameters
size in bits. For RSA the bits returned is the modulus.
For DSA the bits returned are of the public
exponent.

Unknown/unsupported algorithms are mapped to @code{GNUTLS_PK_UNKNOWN} .

@strong{Returns:} a member of the @code{gnutls_pk_algorithm_t}  enumeration on
success, or a negative error code on error.
@end deftypefun