NAME¶

EVP_PKEY_new, EVP_PKEY_up_ref, EVP_PKEY_free, EVP_PKEY_new_raw_private_key, 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 and private key allocation and raw key handling functions

SYNOPSIS¶

#include <openssl/evp.h>

EVP_PKEY *
EVP_PKEY_new(void);

int
EVP_PKEY_up_ref(EVP_PKEY *pkey);

void
EVP_PKEY_free(EVP_PKEY *pkey);

EVP_PKEY *
EVP_PKEY_new_raw_private_key(int type, ENGINE *engine, const unsigned char *rawpriv, size_t rawlen);

EVP_PKEY *
EVP_PKEY_new_raw_public_key(int type, ENGINE *engine, const unsigned char *rawpub, size_t rawlen);

EVP_PKEY *
EVP_PKEY_new_CMAC_key(ENGINE *engine, const unsigned char *rawpriv, size_t rawlen, const EVP_CIPHER *cipher);

EVP_PKEY *
EVP_PKEY_new_mac_key(int type, ENGINE *engine, const unsigned char *rawpriv, int rawlen);

int
EVP_PKEY_get_raw_private_key(const EVP_PKEY *pkey, unsigned char *rawpriv, size_t *rawlen);

int
EVP_PKEY_get_raw_public_key(const EVP_PKEY *pkey, unsigned char *rawpub, size_t *rawlen);

DESCRIPTION¶

The EVP_PKEY structure is used by various OpenSSL functions which require a general private or public key without reference to any particular algorithm.

The EVP_PKEY_new() function allocates an empty EVP_PKEY structure. The reference count is set to 1. To add a private or public key to it, use the functions described in EVP_PKEY_set1_RSA(3).

EVP_PKEY_up_ref() increments the reference count of pkey by 1.

EVP_PKEY_free() decrements the reference count of pkey by 1, and if the reference count reaches zero, frees it up. If pkey is a NULL pointer, no action occurs.

EVP_PKEY_new_raw_private_key() allocates a new EVP_PKEY. The NID of a public key algorithm that supports raw private keys, i.e. EVP_PKEY_HMAC, EVP_PKEY_X25519, or EVP_PKEY_ED25519, is provided in the type argument and rawlen bytes of raw private key data of that type in rawpriv. The public key data is automatically derived from the given private key data, if appropriate for the algorithm type. The ENGINE *engine argument is always ignored and passing NULL is recommended.

EVP_PKEY_new_raw_public_key() works in the same way as EVP_PKEY_new_raw_private_key() except that rawpub points to the raw public key data. The EVP_PKEY structure is initialised without any private key information. Algorithm types that support raw public keys are EVP_PKEY_X25519 and EVP_PKEY_ED25519.

EVP_PKEY_new_CMAC_key() works in the same way as EVP_PKEY_new_raw_private_key() except that it only handles the EVP_PKEY_CMAC algorithm type. The additional cipher argument specifies the cipher algorithm to be used during the creation of the CMAC. It should be a standard encryption only cipher. For example, AEAD and XTS ciphers should not be used.

EVP_PKEY_new_mac_key() is a deprecated function that works in the same way as EVP_PKEY_new_raw_private_key().

EVP_PKEY_get_raw_private_key() writes up to *rawlen bytes of raw private key data to the buffer starting at rawpriv and stores the number of bytes written in *rawlen. The calling application is responsible for ensuring that the buffer is large enough to receive the private key data. If the rawpriv argument is NULL, the number of bytes required to hold the key is stored in *rawlen. This function only works for algorithms that support raw private keys. Currently these are EVP_PKEY_HMAC, EVP_PKEY_X25519, and EVP_PKEY_ED25519.

EVP_PKEY_get_raw_public_key() is similar to EVP_PKEY_get_raw_private_key() except that it writes raw public key data. This function only works for algorithms that support raw public keys. Currently these are EVP_PKEY_X25519 and EVP_PKEY_ED25519.

RETURN VALUES¶

EVP_PKEY_new(), 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_up_ref(), EVP_PKEY_get_raw_private_key(), and EVP_PKEY_get_raw_public_key() return 1 for success or 0 for failure.

SEE ALSO¶

CMAC_Init(3), d2i_PrivateKey(3), evp(3), EVP_PKCS82PKEY(3), EVP_PKEY_asn1_new(3), EVP_PKEY_check(3), EVP_PKEY_cmp(3), EVP_PKEY_CTX_new(3), EVP_PKEY_get_default_digest_nid(3), EVP_PKEY_meth_new(3), EVP_PKEY_print_private(3), EVP_PKEY_set1_RSA(3), EVP_PKEY_size(3), X509_get_pubkey_parameters(3)

HISTORY¶

EVP_PKEY_new() and EVP_PKEY_free() first appeared in SSLeay 0.6.0 and have been available since OpenBSD 2.4.

EVP_PKEY_new_CMAC_key() first appeared in OpenSSL 1.1.1 and has been available since OpenBSD 6.9.

EVP_PKEY_new_mac_key() first appeared in OpenSSL 1.0.0 and has been available since OpenBSD 4.9.

EVP_PKEY_up_ref() first appeared in OpenSSL 1.1.0 and has been available since OpenBSD 6.3.

EVP_PKEY_new_raw_private_key(), EVP_PKEY_new_raw_public_key(), EVP_PKEY_get_raw_private_key(), and EVP_PKEY_get_raw_public_key() first appeared in OpenSSL 1.1.1 and have been available since OpenBSD 7.3.