NAME

       EVP_PKEY_set1_RSA, EVP_PKEY_set1_DSA, EVP_PKEY_set1_DH, EVP_PKEY_set1_EC_KEY,
       EVP_PKEY_get1_RSA, EVP_PKEY_get1_DSA, EVP_PKEY_get1_DH, EVP_PKEY_get1_EC_KEY,
       EVP_PKEY_get0_RSA, EVP_PKEY_get0_DSA, EVP_PKEY_get0_DH, EVP_PKEY_get0_EC_KEY,
       EVP_PKEY_assign_RSA, EVP_PKEY_assign_DSA, EVP_PKEY_assign_DH, EVP_PKEY_assign_EC_KEY,
       EVP_PKEY_get0_hmac, EVP_PKEY_type, EVP_PKEY_id, EVP_PKEY_base_id, EVP_PKEY_set_alias_type,
       EVP_PKEY_set1_engine - EVP_PKEY assignment functions

SYNOPSIS

        #include <openssl/evp.h>

        int EVP_PKEY_set1_RSA(EVP_PKEY *pkey, RSA *key);
        int EVP_PKEY_set1_DSA(EVP_PKEY *pkey, DSA *key);
        int EVP_PKEY_set1_DH(EVP_PKEY *pkey, DH *key);
        int EVP_PKEY_set1_EC_KEY(EVP_PKEY *pkey, EC_KEY *key);

        RSA *EVP_PKEY_get1_RSA(EVP_PKEY *pkey);
        DSA *EVP_PKEY_get1_DSA(EVP_PKEY *pkey);
        DH *EVP_PKEY_get1_DH(EVP_PKEY *pkey);
        EC_KEY *EVP_PKEY_get1_EC_KEY(EVP_PKEY *pkey);

        const unsigned char *EVP_PKEY_get0_hmac(const EVP_PKEY *pkey, size_t *len);
        RSA *EVP_PKEY_get0_RSA(EVP_PKEY *pkey);
        DSA *EVP_PKEY_get0_DSA(EVP_PKEY *pkey);
        DH *EVP_PKEY_get0_DH(EVP_PKEY *pkey);
        EC_KEY *EVP_PKEY_get0_EC_KEY(EVP_PKEY *pkey);

        int EVP_PKEY_assign_RSA(EVP_PKEY *pkey, RSA *key);
        int EVP_PKEY_assign_DSA(EVP_PKEY *pkey, DSA *key);
        int EVP_PKEY_assign_DH(EVP_PKEY *pkey, DH *key);
        int EVP_PKEY_assign_EC_KEY(EVP_PKEY *pkey, EC_KEY *key);

        int EVP_PKEY_id(const EVP_PKEY *pkey);
        int EVP_PKEY_base_id(const EVP_PKEY *pkey);
        int EVP_PKEY_type(int type);
        int EVP_PKEY_set_alias_type(EVP_PKEY *pkey, int type);

        int EVP_PKEY_set1_engine(EVP_PKEY *pkey, ENGINE *engine);

DESCRIPTION

       EVP_PKEY_set1_RSA(), EVP_PKEY_set1_DSA(), EVP_PKEY_set1_DH() and EVP_PKEY_set1_EC_KEY()
       set the key referenced by pkey to key.

       EVP_PKEY_get1_RSA(), EVP_PKEY_get1_DSA(), EVP_PKEY_get1_DH() and EVP_PKEY_get1_EC_KEY()
       return the referenced key in pkey or NULL if the key is not of the correct type.

       EVP_PKEY_get0_hmac(), EVP_PKEY_get0_RSA(), EVP_PKEY_get0_DSA(), EVP_PKEY_get0_DH() and
       EVP_PKEY_get0_EC_KEY() also return the referenced key in pkey or NULL if the key is not of
       the correct type but the reference count of the returned key is not incremented and so
       must not be freed up after use.

       EVP_PKEY_assign_RSA(), EVP_PKEY_assign_DSA(), EVP_PKEY_assign_DH() and
       EVP_PKEY_assign_EC_KEY() also set the referenced key to key however these use the supplied
       key internally and so key will be freed when the parent pkey is freed.

       EVP_PKEY_base_id() returns the type of pkey. For example an RSA key will return
       EVP_PKEY_RSA.

       EVP_PKEY_id() returns the actual OID associated with pkey. Historically keys using the
       same algorithm could use different OIDs. For example an RSA key could use the OIDs
       corresponding to the NIDs NID_rsaEncryption (equivalent to EVP_PKEY_RSA) or NID_rsa
       (equivalent to EVP_PKEY_RSA2). The use of alternative non-standard OIDs is now rare so
       EVP_PKEY_RSA2 et al are not often seen in practice.

       EVP_PKEY_type() returns the underlying type of the NID type. For example
       EVP_PKEY_type(EVP_PKEY_RSA2) will return EVP_PKEY_RSA.

       EVP_PKEY_set1_engine() sets the ENGINE handling pkey to engine. It must be called after
       the key algorithm and components are set up.  If engine does not include an
       EVP_PKEY_METHOD for pkey an error occurs.

       EVP_PKEY_set_alias_type() allows modifying a EVP_PKEY to use a different set of algorithms
       than the default. This is currently used to support SM2 keys, which use an identical
       encoding to ECDSA.

NOTES

       In accordance with the OpenSSL naming convention the key obtained from or assigned to the
       pkey using the 1 functions must be freed as well as pkey.

       EVP_PKEY_assign_RSA(), EVP_PKEY_assign_DSA(), EVP_PKEY_assign_DH() and
       EVP_PKEY_assign_EC_KEY() are implemented as macros.

       Most applications wishing to know a key type will simply call EVP_PKEY_base_id() and will
       not care about the actual type: which will be identical in almost all cases.

       Previous versions of this document suggested using EVP_PKEY_type(pkey->type) to determine
       the type of a key. Since EVP_PKEY is now opaque this is no longer possible: the equivalent
       is EVP_PKEY_base_id(pkey).

       EVP_PKEY_set1_engine() is typically used by an ENGINE returning an HSM key as part of its
       routine to load a private key.

EXAMPLES

       After loading an ECC key, it is possible to convert it to using SM2 algorithms with
       EVP_PKEY_set_alias_type:

        EVP_PKEY_set_alias_type(pkey, EVP_PKEY_SM2);

RETURN VALUES

       EVP_PKEY_set1_RSA(), EVP_PKEY_set1_DSA(), EVP_PKEY_set1_DH() and EVP_PKEY_set1_EC_KEY()
       return 1 for success or 0 for failure.

       EVP_PKEY_get1_RSA(), EVP_PKEY_get1_DSA(), EVP_PKEY_get1_DH() and EVP_PKEY_get1_EC_KEY()
       return the referenced key or NULL if an error occurred.

       EVP_PKEY_assign_RSA(), EVP_PKEY_assign_DSA(), EVP_PKEY_assign_DH() and
       EVP_PKEY_assign_EC_KEY() return 1 for success and 0 for failure.

       EVP_PKEY_base_id(), EVP_PKEY_id() and EVP_PKEY_type() return a key type or NID_undef
       (equivalently EVP_PKEY_NONE) on error.

       EVP_PKEY_set1_engine() returns 1 for success and 0 for failure.

       EVP_PKEY_set_alias_type() returns 1 for success and 0 for error.

SEE ALSO

       EVP_PKEY_new(3)

COPYRIGHT

       Copyright 2002-2018 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 <https://www.openssl.org/source/license.html>.