EVP_PKEY_NEW(3ossl) OpenSSL EVP_PKEY_NEW(3ossl)
NAME
EVP_PKEY, EVP_PKEY_new, EVP_PKEY_up_ref, EVP_PKEY_dup, EVP_PKEY_free,
EVP_PKEY_new_raw_private_key_ex, EVP_PKEY_new_raw_private_key,
EVP_PKEY_new_raw_public_key_ex, EVP_PKEY_new_raw_public_key,
EVP_PKEY_new_CMAC_key, EVP_PKEY_new_mac_key,
EVP_PKEY_get_raw_private_key, EVP_PKEY_get_raw_public_key -
public/private key allocation and raw key handling functions
SYNOPSIS
#include <openssl/evp.h>
typedef evp_pkey_st EVP_PKEY;
EVP_PKEY *EVP_PKEY_new(void);
int EVP_PKEY_up_ref(EVP_PKEY *key);
EVP_PKEY *EVP_PKEY_dup(EVP_PKEY *key);
void EVP_PKEY_free(EVP_PKEY *key);
EVP_PKEY *EVP_PKEY_new_raw_private_key_ex(OSSL_LIB_CTX *libctx,
const char *keytype,
const char *propq,
const unsigned char *key,
size_t keylen);
EVP_PKEY *EVP_PKEY_new_raw_private_key(int type, ENGINE *e,
const unsigned char *key, size_t keylen);
EVP_PKEY *EVP_PKEY_new_raw_public_key_ex(OSSL_LIB_CTX *libctx,
const char *keytype,
const char *propq,
const unsigned char *key,
size_t keylen);
EVP_PKEY *EVP_PKEY_new_raw_public_key(int type, ENGINE *e,
const unsigned char *key, size_t keylen);
EVP_PKEY *EVP_PKEY_new_mac_key(int type, ENGINE *e, const unsigned char *key,
int keylen);
int EVP_PKEY_get_raw_private_key(const EVP_PKEY *pkey, unsigned char *priv,
size_t *len);
int EVP_PKEY_get_raw_public_key(const EVP_PKEY *pkey, unsigned char *pub,
size_t *len);
The following function has been deprecated since OpenSSL 3.0, and can be
hidden entirely by defining OPENSSL_API_COMPAT with a suitable version
value, see openssl_user_macros(7):
EVP_PKEY *EVP_PKEY_new_CMAC_key(ENGINE *e, const unsigned char *priv,
size_t len, const EVP_CIPHER *cipher);
DESCRIPTION
EVP_PKEY is a generic structure to hold diverse types of asymmetric keys
(also known as "key pairs"), and can be used for diverse operations, like
signing, verifying signatures, key derivation, etc. The asymmetric keys
themselves are often referred to as the "internal key", and are handled
by backends, such as providers (through EVP_KEYMGMT(3)) or ENGINEs.
Conceptually, an EVP_PKEY internal key may hold a private key, a public
key, or both (a keypair), and along with those, key parameters if the key
type requires them. The presence of these components determine what
operations can be made; for example, signing normally requires the
presence of a private key, and verifying normally requires the presence
of a public key.
EVP_PKEY has also been used for MAC algorithm that were conceived as
producing signatures, although not being public key algorithms;
"POLY1305", "SIPHASH", "HMAC", "CMAC". This usage is considered legacy
and is discouraged in favor of the EVP_MAC(3) API.
The EVP_PKEY_new(3) function allocates an empty EVP_PKEY structure which
is used by OpenSSL to store public and private keys. The reference count
is set to 1.
EVP_PKEY_up_ref() increments the reference count of key.
EVP_PKEY_dup() duplicates the key. The key must not be ENGINE based or a
raw key, otherwise the duplication will fail.
EVP_PKEY_free() decrements the reference count of key and, if the
reference count is zero, frees it up. If key is NULL, nothing is done.
EVP_PKEY_new_raw_private_key_ex() allocates a new EVP_PKEY. Unless an
engine should be used for the key type, a provider for the key is found
using the library context libctx and the property query string propq. The
keytype argument indicates what kind of key this is. The value should be
a string for a public key algorithm that supports raw private keys, i.e
one of "X25519", "ED25519", "X448" or "ED448". key points to the raw
private key data for this EVP_PKEY which should be of length keylen. The
length should be appropriate for the type of the key. The public key data
will be automatically derived from the given private key data (if
appropriate for the algorithm type).
EVP_PKEY_new_raw_private_key() does the same as
EVP_PKEY_new_raw_private_key_ex() except that the default library context
and default property query are used instead. If e is non-NULL then the
new EVP_PKEY structure is associated with the engine e. The type argument
indicates what kind of key this is. The value should be a NID for a
public key algorithm that supports raw private keys, i.e. one of
EVP_PKEY_X25519, EVP_PKEY_ED25519, EVP_PKEY_X448 or EVP_PKEY_ED448.
EVP_PKEY_new_raw_private_key_ex() and EVP_PKEY_new_raw_private_key() may
also be used with most MACs implemented as public key algorithms, so key
types such as "HMAC", "POLY1305", "SIPHASH", or their NID form
EVP_PKEY_POLY1305, EVP_PKEY_SIPHASH, EVP_PKEY_HMAC are also accepted.
This usage is, as mentioned above, discouraged in favor of the EVP_MAC(3)
API.
EVP_PKEY_new_raw_public_key_ex() works in the same way as
EVP_PKEY_new_raw_private_key_ex() except that key points to the raw
public key data. The EVP_PKEY structure will be initialised without any
private key information. Algorithm types that support raw public keys are
"X25519", "ED25519", "X448" or "ED448".
EVP_PKEY_new_raw_public_key() works in the same way as
EVP_PKEY_new_raw_private_key() except that key points to the raw public
key data. The EVP_PKEY structure will be initialised without any private
key information. Algorithm types that support raw public keys are
EVP_PKEY_X25519, EVP_PKEY_ED25519, EVP_PKEY_X448 or EVP_PKEY_ED448.
EVP_PKEY_new_mac_key() works in the same way as
EVP_PKEY_new_raw_private_key(). New applications should use
EVP_PKEY_new_raw_private_key() instead.
EVP_PKEY_get_raw_private_key() fills the buffer provided by priv with raw
private key data. The size of the priv buffer should be in *len on entry
to the function, and on exit *len is updated with the number of bytes
actually written. If the buffer priv is NULL then *len is populated with
the number of bytes required to hold the key. The calling application is
responsible for ensuring that the buffer is large enough to receive the
private key data. This function only works for algorithms that support
raw private keys. Currently this is: EVP_PKEY_HMAC, EVP_PKEY_POLY1305,
EVP_PKEY_SIPHASH, EVP_PKEY_X25519, EVP_PKEY_ED25519, EVP_PKEY_X448 or
EVP_PKEY_ED448.
EVP_PKEY_get_raw_public_key() fills the buffer provided by pub with raw
public key data. The size of the pub buffer should be in *len on entry to
the function, and on exit *len is updated with the number of bytes
actually written. If the buffer pub is NULL then *len is populated with
the number of bytes required to hold the key. The calling application is
responsible for ensuring that the buffer is large enough to receive the
public key data. This function only works for algorithms that support raw
public keys. Currently this is: EVP_PKEY_X25519, EVP_PKEY_ED25519,
EVP_PKEY_X448 or EVP_PKEY_ED448.
EVP_PKEY_new_CMAC_key() works in the same way as
EVP_PKEY_new_raw_private_key() except it is only for the EVP_PKEY_CMAC
algorithm type. In addition to the raw private key data, it also takes a
cipher algorithm to be used during creation of a CMAC in the cipher
argument. The cipher should be a standard encryption-only cipher. For
example AEAD and XTS ciphers should not be used.
Applications should use the EVP_MAC(3) API instead and set the
OSSL_MAC_PARAM_CIPHER parameter on the EVP_MAC_CTX object with the name
of the cipher being used.
NOTES
The EVP_PKEY structure is used by various OpenSSL functions which require
a general private key without reference to any particular algorithm.
The structure returned by EVP_PKEY_new(3) is empty. To add a private or
public key to this empty structure use the appropriate functions
described in EVP_PKEY_set1_RSA(3), EVP_PKEY_set1_DSA(3),
EVP_PKEY_set1_DH(3) or EVP_PKEY_set1_EC_KEY(3).
RETURN VALUES
EVP_PKEY_new(3), EVP_PKEY_new_raw_private_key(),
EVP_PKEY_new_raw_public_key(), EVP_PKEY_new_CMAC_key() and
EVP_PKEY_new_mac_key() return either the newly allocated EVP_PKEY
structure or NULL if an error occurred.
EVP_PKEY_dup() returns the key duplicate or NULL if an error occurred.
EVP_PKEY_up_ref(), EVP_PKEY_get_raw_private_key() and
EVP_PKEY_get_raw_public_key() return 1 for success and 0 for failure.
SEE ALSO
EVP_PKEY_set1_RSA(3), EVP_PKEY_set1_DSA(3), EVP_PKEY_set1_DH(3) or
EVP_PKEY_set1_EC_KEY(3)
HISTORY
The EVP_PKEY_new(3) and EVP_PKEY_free() functions exist in all versions of
OpenSSL.
The EVP_PKEY_up_ref() function was added in OpenSSL 1.1.0.
The EVP_PKEY_new_raw_private_key(), EVP_PKEY_new_raw_public_key(),
EVP_PKEY_new_CMAC_key(), EVP_PKEY_new_raw_private_key() and
EVP_PKEY_get_raw_public_key() functions were added in OpenSSL 1.1.1.
The EVP_PKEY_dup(), EVP_PKEY_new_raw_private_key_ex(), and
EVP_PKEY_new_raw_public_key_ex() functions were added in OpenSSL 3.0.
The EVP_PKEY_new_CMAC_key() was deprecated in OpenSSL 3.0.
The documentation of EVP_PKEY was amended in OpenSSL 3.0 to allow there
to be the private part of the keypair without the public part, where this
was previously implied to be disallowed.
COPYRIGHT
Copyright 2002-2022 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (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
<https://www.openssl.org/source/license.html>.
3.1.0 2023-03-14 EVP_PKEY_NEW(3ossl)
openssl 3.1.0 - Generated Fri Mar 17 16:11:39 CDT 2023