EVP_PKEY_copy_parameters, EVP_PKEY_missing_parameters, EVP_PKEY_cmp_parameters, EVP_PKEY_cmp - public key parameter and comparison functions
#include <openssl/evp.h>
int EVP_PKEY_missing_parameters(const EVP_PKEY *pkey); int EVP_PKEY_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from);
int EVP_PKEY_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b); int EVP_PKEY_cmp(const EVP_PKEY *a, const EVP_PKEY *b);
The function EVP_PKEY_missing_parameters() returns 1 if the public key
parameters of pkey are missing and 0 if they are present or the algorithm
doesn't use parameters.
The function EVP_PKEY_copy_parameters() copies the parameters from key
from to key to.
The funcion EVP_PKEY_cmp_parameters() compares the parameters of keys
a and b.
The funcion EVP_PKEY_cmp() compares the public key components and paramters
(if present) of keys a and b.
The main purpose of the functions EVP_PKEY_missing_parameters() and
EVP_PKEY_copy_parameters() is to handle public keys in certificates where the
parameters are sometimes omitted from a public key if they are inherited from
the CA that signed it.
Since OpenSSL private keys contain public key components too the function
EVP_PKEY_cmp() can also be used to determine if a private key matches
a public key.
The function EVP_PKEY_missing_parameters() returns 1 if the public key
parameters of pkey are missing and 0 if they are present or the algorithm
doesn't use parameters.
These functions EVP_PKEY_copy_parameters() returns 1 for success and 0 for
failure.
The function EVP_PKEY_cmp_parameters() and EVP_PKEY_cmp() return 1 if the
keys match, 0 if they don't match, -1 if the key types are different and
-2 if the operation is not supported.