NAME

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);
 const unsigned char *EVP_PKEY_get0_poly1305(const EVP_PKEY *pkey, size_t *len);
 const unsigned char *EVP_PKEY_get0_siphash(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_assign_POLY1305(EVP_PKEY *pkey, ASN1_OCTET_STRING *key);
 int EVP_PKEY_assign_SIPHASH(EVP_PKEY *pkey, ASN1_OCTET_STRING *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);

 ENGINE *EVP_PKEY_get0_engine(const EVP_PKEY *pkey);
 int EVP_PKEY_set1_engine(EVP_PKEY *pkey, ENGINE *engine);

DESCRIPTION

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_poly1305(), EVP_PKEY_get0_siphash(), 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(), EVP_PKEY_assign_EC_KEY(), EVP_PKEY_assign_POLY1305() and EVP_PKEY_assign_SIPHASH() 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_get0_engine() returns a reference to the ENGINE handling pkey.

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

EVP_PKEY_assign_RSA(), EVP_PKEY_assign_DSA(), EVP_PKEY_assign_DH(), EVP_PKEY_assign_EC_KEY(), EVP_PKEY_assign_POLY1305() and EVP_PKEY_assign_SIPHASH() 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.

RETURN VALUES

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(), EVP_PKEY_assign_EC_KEY(), EVP_PKEY_assign_POLY1305() and EVP_PKEY_assign_SIPHASH() 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.

EXAMPLES

 EVP_PKEY_set_alias_type(pkey, EVP_PKEY_SM2);

SEE ALSO

COPYRIGHT

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>.