/usr/man/cat.3/EVP_PKEY_cmp_parameters.3

EVP_PKEY_cmp(3)              OpenSSL              EVP_PKEY_cmp(3)

NAME

     EVP_PKEY_copy_parameters, EVP_PKEY_missing_parameters,
     EVP_PKEY_cmp_parameters, EVP_PKEY_cmp - public key parameter
     and comparison functions

SYNOPSIS

      #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);

DESCRIPTION

     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. An error is returned if
     the parameters are missing in from or present in both from
     and to and mismatch. If the parameters in from and to are
     both present and match this function has no effect.

     The function EVP_PKEY_cmp_parameters() compares the
     parameters of keys a and b.

     The function EVP_PKEY_cmp() compares the public key
     components and paramters (if present) of keys a and b.

NOTES

     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.

RETURN VALUES

     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

1.0.2t               Last change: 2019-09-10                    1

EVP_PKEY_cmp(3)              OpenSSL              EVP_PKEY_cmp(3)

     key types are different and -2 if the operation is not
     supported.

SEE ALSO

     EVP_PKEY_CTX_new(3), EVP_PKEY_keygen(3)

1.0.2t               Last change: 2019-09-10                    2

See also EVP_PKEY_cmp(3)
See also EVP_PKEY_copy_parameters(3)
See also EVP_PKEY_missing_parameters(3)