=pod
=head1 NAME
EVP_PKEY_ASN1_METHOD,
EVP_PKEY_asn1_new,
EVP_PKEY_asn1_copy,
EVP_PKEY_asn1_free,
EVP_PKEY_asn1_add0,
EVP_PKEY_asn1_add_alias,
EVP_PKEY_asn1_set_public,
EVP_PKEY_asn1_set_private,
EVP_PKEY_asn1_set_param,
EVP_PKEY_asn1_set_free,
EVP_PKEY_asn1_set_ctrl,
EVP_PKEY_asn1_set_item,
EVP_PKEY_asn1_set_siginf,
EVP_PKEY_asn1_set_check,
EVP_PKEY_asn1_set_public_check,
EVP_PKEY_asn1_set_param_check,
EVP_PKEY_asn1_set_security_bits,
EVP_PKEY_asn1_set_set_priv_key,
EVP_PKEY_asn1_set_set_pub_key,
EVP_PKEY_asn1_set_get_priv_key,
EVP_PKEY_asn1_set_get_pub_key,
EVP_PKEY_get0_asn1
- manipulating and registering EVP_PKEY_ASN1_METHOD structure
=head1 SYNOPSIS
#include <openssl/evp.h>
typedef struct evp_pkey_asn1_method_st EVP_PKEY_ASN1_METHOD;
EVP_PKEY_ASN1_METHOD *EVP_PKEY_asn1_new(int id, int flags,
const char *pem_str,
const char *info);
void EVP_PKEY_asn1_copy(EVP_PKEY_ASN1_METHOD *dst,
const EVP_PKEY_ASN1_METHOD *src);
void EVP_PKEY_asn1_free(EVP_PKEY_ASN1_METHOD *ameth);
int EVP_PKEY_asn1_add0(const EVP_PKEY_ASN1_METHOD *ameth);
int EVP_PKEY_asn1_add_alias(int to, int from);
void EVP_PKEY_asn1_set_public(EVP_PKEY_ASN1_METHOD *ameth,
int (*pub_decode) (EVP_PKEY *pk,
X509_PUBKEY *pub),
int (*pub_encode) (X509_PUBKEY *pub,
const EVP_PKEY *pk),
int (*pub_cmp) (const EVP_PKEY *a,
const EVP_PKEY *b),
int (*pub_print) (BIO *out,
const EVP_PKEY *pkey,
int indent, ASN1_PCTX *pctx),
int (*pkey_size) (const EVP_PKEY *pk),
int (*pkey_bits) (const EVP_PKEY *pk));
void EVP_PKEY_asn1_set_private(EVP_PKEY_ASN1_METHOD *ameth,
int (*priv_decode) (EVP_PKEY *pk,
const PKCS8_PRIV_KEY_INFO
*p8inf),
int (*priv_encode) (PKCS8_PRIV_KEY_INFO *p8,
const EVP_PKEY *pk),
int (*priv_print) (BIO *out,
const EVP_PKEY *pkey,
int indent,
ASN1_PCTX *pctx));
void EVP_PKEY_asn1_set_param(EVP_PKEY_ASN1_METHOD *ameth,
int (*param_decode) (EVP_PKEY *pkey,
const unsigned char **pder,
int derlen),
int (*param_encode) (const EVP_PKEY *pkey,
unsigned char **pder),
int (*param_missing) (const EVP_PKEY *pk),
int (*param_copy) (EVP_PKEY *to,
const EVP_PKEY *from),
int (*param_cmp) (const EVP_PKEY *a,
const EVP_PKEY *b),
int (*param_print) (BIO *out,
const EVP_PKEY *pkey,
int indent,
ASN1_PCTX *pctx));
void EVP_PKEY_asn1_set_free(EVP_PKEY_ASN1_METHOD *ameth,
void (*pkey_free) (EVP_PKEY *pkey));
void EVP_PKEY_asn1_set_ctrl(EVP_PKEY_ASN1_METHOD *ameth,
int (*pkey_ctrl) (EVP_PKEY *pkey, int op,
long arg1, void *arg2));
void EVP_PKEY_asn1_set_item(EVP_PKEY_ASN1_METHOD *ameth,
int (*item_verify) (EVP_MD_CTX *ctx,
const ASN1_ITEM *it,
void *asn,
X509_ALGOR *a,
ASN1_BIT_STRING *sig,
EVP_PKEY *pkey),
int (*item_sign) (EVP_MD_CTX *ctx,
const ASN1_ITEM *it,
void *asn,
X509_ALGOR *alg1,
X509_ALGOR *alg2,
ASN1_BIT_STRING *sig));
void EVP_PKEY_asn1_set_siginf(EVP_PKEY_ASN1_METHOD *ameth,
int (*siginf_set) (X509_SIG_INFO *siginf,
const X509_ALGOR *alg,
const ASN1_STRING *sig));
void EVP_PKEY_asn1_set_check(EVP_PKEY_ASN1_METHOD *ameth,
int (*pkey_check) (const EVP_PKEY *pk));
void EVP_PKEY_asn1_set_public_check(EVP_PKEY_ASN1_METHOD *ameth,
int (*pkey_pub_check) (const EVP_PKEY *pk));
void EVP_PKEY_asn1_set_param_check(EVP_PKEY_ASN1_METHOD *ameth,
int (*pkey_param_check) (const EVP_PKEY *pk));
void EVP_PKEY_asn1_set_security_bits(EVP_PKEY_ASN1_METHOD *ameth,
int (*pkey_security_bits) (const EVP_PKEY
*pk));
void EVP_PKEY_asn1_set_set_priv_key(EVP_PKEY_ASN1_METHOD *ameth,
int (*set_priv_key) (EVP_PKEY *pk,
const unsigned char
*priv,
size_t len));
void EVP_PKEY_asn1_set_set_pub_key(EVP_PKEY_ASN1_METHOD *ameth,
int (*set_pub_key) (EVP_PKEY *pk,
const unsigned char *pub,
size_t len));
void EVP_PKEY_asn1_set_get_priv_key(EVP_PKEY_ASN1_METHOD *ameth,
int (*get_priv_key) (const EVP_PKEY *pk,
unsigned char *priv,
size_t *len));
void EVP_PKEY_asn1_set_get_pub_key(EVP_PKEY_ASN1_METHOD *ameth,
int (*get_pub_key) (const EVP_PKEY *pk,
unsigned char *pub,
size_t *len));
const EVP_PKEY_ASN1_METHOD *EVP_PKEY_get0_asn1(const EVP_PKEY *pkey);
=head1 DESCRIPTION
B<EVP_PKEY_ASN1_METHOD> is a structure which holds a set of ASN.1
conversion, printing and information methods for a specific public key
algorithm.
There are two places where the B<EVP_PKEY_ASN1_METHOD> objects are
stored: one is a built-in array representing the standard methods for
different algorithms, and the other one is a stack of user-defined
application-specific methods, which can be manipulated by using
L<EVP_PKEY_asn1_add0(3)>.
=head2 Methods
The methods are the underlying implementations of a particular public
key algorithm present by the B<EVP_PKEY> object.
int (*pub_decode) (EVP_PKEY *pk, X509_PUBKEY *pub);
int (*pub_encode) (X509_PUBKEY *pub, const EVP_PKEY *pk);
int (*pub_cmp) (const EVP_PKEY *a, const EVP_PKEY *b);
int (*pub_print) (BIO *out, const EVP_PKEY *pkey, int indent,
ASN1_PCTX *pctx);
The pub_decode() and pub_encode() methods are called to decode /
encode B<X509_PUBKEY> ASN.1 parameters to / from B<pk>.
They MUST return 0 on error, 1 on success.
They're called by L<X509_PUBKEY_get0(3)> and L<X509_PUBKEY_set(3)>.
The pub_cmp() method is called when two public keys are to be
compared.
It MUST return 1 when the keys are equal, 0 otherwise.
It's called by L<EVP_PKEY_cmp(3)>.
The pub_print() method is called to print a public key in humanly
readable text to B<out>, indented B<indent> spaces.
It MUST return 0 on error, 1 on success.
It's called by L<EVP_PKEY_print_public(3)>.
int (*priv_decode) (EVP_PKEY *pk, const PKCS8_PRIV_KEY_INFO *p8inf);
int (*priv_encode) (PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pk);
int (*priv_print) (BIO *out, const EVP_PKEY *pkey, int indent,
ASN1_PCTX *pctx);
The priv_decode() and priv_encode() methods are called to decode /
encode B<PKCS8_PRIV_KEY_INFO> form private key to / from B<pk>.
They MUST return 0 on error, 1 on success.
They're called by L<EVP_PKCS82PKEY(3)> and L<EVP_PKEY2PKCS8(3)>.
The priv_print() method is called to print a private key in humanly
readable text to B<out>, indented B<indent> spaces.
It MUST return 0 on error, 1 on success.
It's called by L<EVP_PKEY_print_private(3)>.
int (*pkey_size) (const EVP_PKEY *pk);
int (*pkey_bits) (const EVP_PKEY *pk);
int (*pkey_security_bits) (const EVP_PKEY *pk);
The pkey_size() method returns the key size in bytes.
It's called by L<EVP_PKEY_size(3)>.
The pkey_bits() method returns the key size in bits.
It's called by L<EVP_PKEY_bits(3)>.
int (*param_decode) (EVP_PKEY *pkey,
const unsigned char **pder, int derlen);
int (*param_encode) (const EVP_PKEY *pkey, unsigned char **pder);
int (*param_missing) (const EVP_PKEY *pk);
int (*param_copy) (EVP_PKEY *to, const EVP_PKEY *from);
int (*param_cmp) (const EVP_PKEY *a, const EVP_PKEY *b);
int (*param_print) (BIO *out, const EVP_PKEY *pkey, int indent,
ASN1_PCTX *pctx);
The param_decode() and param_encode() methods are called to decode /
encode DER formatted parameters to / from B<pk>.
They MUST return 0 on error, 1 on success.
They're called by L<PEM_read_bio_Parameters(3)> and the B<file:>
L<OSSL_STORE_LOADER(3)>.
The param_missing() method returns 0 if a key parameter is missing,
otherwise 1.
It's called by L<EVP_PKEY_missing_parameters(3)>.
The param_copy() method copies key parameters from B<from> to B<to>.
It MUST return 0 on error, 1 on success.
It's called by L<EVP_PKEY_copy_parameters(3)>.
The param_cmp() method compares the parameters of keys B<a> and B<b>.
It MUST return 1 when the keys are equal, 0 when not equal, or a
negative number on error.
It's called by L<EVP_PKEY_cmp_parameters(3)>.
The param_print() method prints the private key parameters in humanly
readable text to B<out>, indented B<indent> spaces.
It MUST return 0 on error, 1 on success.
It's called by L<EVP_PKEY_print_params(3)>.
int (*sig_print) (BIO *out,
const X509_ALGOR *sigalg, const ASN1_STRING *sig,
int indent, ASN1_PCTX *pctx);
The sig_print() method prints a signature in humanly readable text to
B<out>, indented B<indent> spaces.
B<sigalg> contains the exact signature algorithm.
If the signature in B<sig> doesn't correspond to what this method
expects, X509_signature_dump() must be used as a last resort.
It MUST return 0 on error, 1 on success.
It's called by L<X509_signature_print(3)>.
void (*pkey_free) (EVP_PKEY *pkey);
The pkey_free() method helps freeing the internals of B<pkey>.
It's called by L<EVP_PKEY_free(3)>, L<EVP_PKEY_set_type(3)>,
L<EVP_PKEY_set_type_str(3)>, and L<EVP_PKEY_assign(3)>.
int (*pkey_ctrl) (EVP_PKEY *pkey, int op, long arg1, void *arg2);
The pkey_ctrl() method adds extra algorithm specific control.
It's called by L<EVP_PKEY_get_default_digest_nid(3)>,
L<EVP_PKEY_set1_tls_encodedpoint(3)>,
L<EVP_PKEY_get1_tls_encodedpoint(3)>, L<PKCS7_SIGNER_INFO_set(3)>,
L<PKCS7_RECIP_INFO_set(3)>, ...
int (*old_priv_decode) (EVP_PKEY *pkey,
const unsigned char **pder, int derlen);
int (*old_priv_encode) (const EVP_PKEY *pkey, unsigned char **pder);
The old_priv_decode() and old_priv_encode() methods decode / encode
they private key B<pkey> from / to a DER formatted array.
These are exclusively used to help decoding / encoding older (pre
PKCS#8) PEM formatted encrypted private keys.
old_priv_decode() MUST return 0 on error, 1 on success.
old_priv_encode() MUST the return same kind of values as
i2d_PrivateKey().
They're called by L<d2i_PrivateKey(3)> and L<i2d_PrivateKey(3)>.
int (*item_verify) (EVP_MD_CTX *ctx, const ASN1_ITEM *it, void *asn,
X509_ALGOR *a, ASN1_BIT_STRING *sig, EVP_PKEY *pkey);
int (*item_sign) (EVP_MD_CTX *ctx, const ASN1_ITEM *it, void *asn,
X509_ALGOR *alg1, X509_ALGOR *alg2,
ASN1_BIT_STRING *sig);
The item_sign() and item_verify() methods make it possible to have
algorithm specific signatures and verification of them.
item_sign() MUST return one of:
=over 4
=item <=0
error
=item Z<>1
item_sign() did everything, OpenSSL internals just needs to pass the
signature length back.
=item Z<>2
item_sign() did nothing, OpenSSL internal standard routines are
expected to continue with the default signature production.
=item Z<>3
item_sign() set the algorithm identifier B<algor1> and B<algor2>,
OpenSSL internals should just sign using those algorithms.
=back
item_verify() MUST return one of:
=over 4
=item <=0
error
=item Z<>1
item_sign() did everything, OpenSSL internals just needs to pass the
signature length back.
=item Z<>2
item_sign() did nothing, OpenSSL internal standard routines are
expected to continue with the default signature production.
=back
item_verify() and item_sign() are called by L<ASN1_item_verify(3)> and
L<ASN1_item_sign(3)>, and by extension, L<X509_verify(3)>,
L<X509_REQ_verify(3)>, L<X509_sign(3)>, L<X509_REQ_sign(3)>, ...
int (*siginf_set) (X509_SIG_INFO *siginf, const X509_ALGOR *alg,
const ASN1_STRING *sig);
The siginf_set() method is used to set custom B<X509_SIG_INFO>
parameters.
It MUST return 0 on error, or 1 on success.
It's called as part of L<X509_check_purpose(3)>, L<X509_check_ca(3)>
and L<X509_check_issued(3)>.
int (*pkey_check) (const EVP_PKEY *pk);
int (*pkey_public_check) (const EVP_PKEY *pk);
int (*pkey_param_check) (const EVP_PKEY *pk);
The pkey_check(), pkey_public_check() and pkey_param_check() methods are used
to check the validity of B<pk> for key-pair, public component and parameters,
respectively.
They MUST return 0 for an invalid key, or 1 for a valid key.
They are called by L<EVP_PKEY_check(3)>, L<EVP_PKEY_public_check(3)> and
L<EVP_PKEY_param_check(3)> respectively.
int (*set_priv_key) (EVP_PKEY *pk, const unsigned char *priv, size_t len);
int (*set_pub_key) (EVP_PKEY *pk, const unsigned char *pub, size_t len);
The set_priv_key() and set_pub_key() methods are used to set the raw private and
public key data for an EVP_PKEY. They MUST return 0 on error, or 1 on success.
They are called by L<EVP_PKEY_new_raw_private_key(3)>, and
L<EVP_PKEY_new_raw_public_key(3)> respectively.
=head2 Functions
EVP_PKEY_asn1_new() creates and returns a new B<EVP_PKEY_ASN1_METHOD>
object, and associates the given B<id>, B<flags>, B<pem_str> and
B<info>.
B<id> is a NID, B<pem_str> is the PEM type string, B<info> is a
descriptive string.
The following B<flags> are supported:
ASN1_PKEY_SIGPARAM_NULL
If B<ASN1_PKEY_SIGPARAM_NULL> is set, then the signature algorithm
parameters are given the type B<V_ASN1_NULL> by default, otherwise
they will be given the type B<V_ASN1_UNDEF> (i.e. the parameter is
omitted).
See L<X509_ALGOR_set0(3)> for more information.
EVP_PKEY_asn1_copy() copies an B<EVP_PKEY_ASN1_METHOD> object from
B<src> to B<dst>.
This function is not thread safe, it's recommended to only use this
when initializing the application.
EVP_PKEY_asn1_free() frees an existing B<EVP_PKEY_ASN1_METHOD> pointed
by B<ameth>.
EVP_PKEY_asn1_add0() adds B<ameth> to the user defined stack of
methods unless another B<EVP_PKEY_ASN1_METHOD> with the same NID is
already there.
This function is not thread safe, it's recommended to only use this
when initializing the application.
EVP_PKEY_asn1_add_alias() creates an alias with the NID B<to> for the
B<EVP_PKEY_ASN1_METHOD> with NID B<from> unless another
B<EVP_PKEY_ASN1_METHOD> with the same NID is already added.
This function is not thread safe, it's recommended to only use this
when initializing the application.
EVP_PKEY_asn1_set_public(), EVP_PKEY_asn1_set_private(),
EVP_PKEY_asn1_set_param(), EVP_PKEY_asn1_set_free(),
EVP_PKEY_asn1_set_ctrl(), EVP_PKEY_asn1_set_item(),
EVP_PKEY_asn1_set_siginf(), EVP_PKEY_asn1_set_check(),
EVP_PKEY_asn1_set_public_check(), EVP_PKEY_asn1_set_param_check(),
EVP_PKEY_asn1_set_security_bits(), EVP_PKEY_asn1_set_set_priv_key(),
EVP_PKEY_asn1_set_set_pub_key(), EVP_PKEY_asn1_set_get_priv_key() and
EVP_PKEY_asn1_set_get_pub_key() set the diverse methods of the given
B<EVP_PKEY_ASN1_METHOD> object.
EVP_PKEY_get0_asn1() finds the B<EVP_PKEY_ASN1_METHOD> associated
with the key B<pkey>.
=head1 RETURN VALUES
EVP_PKEY_asn1_new() returns NULL on error, or a pointer to an
B<EVP_PKEY_ASN1_METHOD> object otherwise.
EVP_PKEY_asn1_add0() and EVP_PKEY_asn1_add_alias() return 0 on error,
or 1 on success.
EVP_PKEY_get0_asn1() returns NULL on error, or a pointer to a constant
B<EVP_PKEY_ASN1_METHOD> object otherwise.
=head1 COPYRIGHT
Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the OpenSSL license (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
in the file LICENSE in the source distribution or at
L<https://www.openssl.org/source/license.html>.
=cut