EVP_PKEY_cmp.pod revision 238405 
1=pod
2
3=head1 NAME
4
5EVP_PKEY_copy_parameters, EVP_PKEY_missing_parameters, EVP_PKEY_cmp_parameters, EVP_PKEY_cmp - public key parameter and comparison functions
6
7=head1 SYNOPSIS
8
9 #include <openssl/evp.h>
10
11 int EVP_PKEY_missing_parameters(const EVP_PKEY *pkey);
12 int EVP_PKEY_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from);
13
14 int EVP_PKEY_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b);
15 int EVP_PKEY_cmp(const EVP_PKEY *a, const EVP_PKEY *b);
16
17=head1 DESCRIPTION
18
19The function EVP_PKEY_missing_parameters() returns 1 if the public key
20parameters of B<pkey> are missing and 0 if they are present or the algorithm
21doesn't use parameters.
22
23The function EVP_PKEY_copy_parameters() copies the parameters from key
24B<from> to key B<to>.
25
26The funcion EVP_PKEY_cmp_parameters() compares the parameters of keys
27B<a> and B<b>.
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29The funcion EVP_PKEY_cmp() compares the public key components and paramters
30(if present) of keys B<a> and B<b>.
31
32=head1 NOTES
33
34The main purpose of the functions EVP_PKEY_missing_parameters() and
35EVP_PKEY_copy_parameters() is to handle public keys in certificates where the
36parameters are sometimes omitted from a public key if they are inherited from
37the CA that signed it.
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39Since OpenSSL private keys contain public key components too the function
40EVP_PKEY_cmp() can also be used to determine if a private key matches
41a public key.
42
43=head1 RETURN VALUES
44
45The function EVP_PKEY_missing_parameters() returns 1 if the public key
46parameters of B<pkey> are missing and 0 if they are present or the algorithm
47doesn't use parameters.
48
49These functions EVP_PKEY_copy_parameters() returns 1 for success and 0 for
50failure.
51
52The function EVP_PKEY_cmp_parameters() and EVP_PKEY_cmp() return 1 if the
53keys match, 0 if they don't match, -1 if the key types are different and
54-2 if the operation is not supported.
55
56=head1 SEE ALSO
57
58L<EVP_PKEY_CTX_new(3)|EVP_PKEY_CTX_new(3)>,
59L<EVP_PKEY_keygen(3)|EVP_PKEY_keygen(3)> 
60
61=cut
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