a high level API with the advantage of transparently handling keys
stored in memory and keys present in smart cards.

‘INT *note gnutls_privkey_init:: (gnutls_privkey_t * KEY)’
‘INT *note gnutls_privkey_import_url:: (gnutls_privkey_t KEY, const char * URL, unsigned int FLAGS)’
‘INT *note gnutls_privkey_import_x509_raw:: (gnutls_privkey_t PKEY, const gnutls_datum_t * DATA, gnutls_x509_crt_fmt_t FORMAT, const char * PASSWORD, unsigned int FLAGS)’
‘INT *note gnutls_privkey_sign_data:: (gnutls_privkey_t SIGNER, gnutls_digest_algorithm_t HASH, unsigned int FLAGS, const gnutls_datum_t * DATA, gnutls_datum_t * SIGNATURE)’
‘INT *note gnutls_privkey_sign_hash:: (gnutls_privkey_t SIGNER, gnutls_digest_algorithm_t HASH_ALGO, unsigned int FLAGS, const gnutls_datum_t * HASH_DATA, gnutls_datum_t * SIGNATURE)’
‘VOID *note gnutls_privkey_deinit:: (gnutls_privkey_t KEY)’

‘INT *note gnutls_pubkey_init:: (gnutls_pubkey_t * KEY)’
‘INT *note gnutls_pubkey_import_url:: (gnutls_pubkey_t KEY, const char * URL, unsigned int FLAGS)’
‘INT *note gnutls_pubkey_import_x509:: (gnutls_pubkey_t KEY, gnutls_x509_crt_t CRT, unsigned int FLAGS)’
‘INT *note gnutls_pubkey_verify_data2:: (gnutls_pubkey_t PUBKEY, gnutls_sign_algorithm_t ALGO, unsigned int FLAGS, const gnutls_datum_t * DATA, const gnutls_datum_t * SIGNATURE)’
‘INT *note gnutls_pubkey_verify_hash2:: (gnutls_pubkey_t KEY, gnutls_sign_algorithm_t ALGO, unsigned int FLAGS, const gnutls_datum_t * HASH, const gnutls_datum_t * SIGNATURE)’
‘VOID *note gnutls_pubkey_deinit:: (gnutls_pubkey_t KEY)’

Keys stored in memory can be imported using functions like *note
gnutls_privkey_import_x509_raw::, while keys on smart cards or HSMs
should be imported using their PKCS#11 URL with *note
gnutls_privkey_import_url::.

If any of the smart card operations require PIN, that should be provided
either by setting the global PIN function (*note
gnutls_pkcs11_set_pin_function::), or better with the targeted to
structures functions such as *note gnutls_privkey_set_pin_function::.

9.2.1 Key generation
--------------------

All supported key types (including RSA, DSA, ECDSA, Ed25519, Ed448) can
be generated with GnuTLS. They can be generated with the simpler *note
gnutls_privkey_generate:: or with the more advanced *note
gnutls_privkey_generate2::.

 -- Function: int gnutls_privkey_generate2 (gnutls_privkey_t PKEY,
          gnutls_pk_algorithm_t ALGO, unsigned int BITS, unsigned int
          FLAGS, const gnutls_keygen_data_st * DATA, unsigned DATA_SIZE)
     PKEY: The private key

     ALGO: is one of the algorithms in ‘gnutls_pk_algorithm_t’ .

     BITS: the size of the modulus

     FLAGS: Must be zero or flags from ‘gnutls_privkey_flags_t’ .

     DATA: Allow specifying ‘gnutls_keygen_data_st’ types such as the
     seed to be used.

     DATA_SIZE: The number of ‘data’ available.

     This function will generate a random private key.  Note that this
     function must be called on an initialized private key.

     The flag ‘GNUTLS_PRIVKEY_FLAG_PROVABLE’ instructs the key
     generation process to use algorithms like Shawe-Taylor (from FIPS
     PUB186-4) which generate provable parameters out of a seed for RSA
     and DSA keys.  On DSA keys the PQG parameters are generated using
     the seed, while on RSA the two primes.  To specify an explicit seed
     (by default a random seed is used), use the ‘data’ with a
     ‘GNUTLS_KEYGEN_SEED’ type.

     Note that when generating an elliptic curve key, the curve can be
     substituted in the place of the bits parameter using the
     ‘GNUTLS_CURVE_TO_BITS()’ macro.

     To export the generated keys in memory or in files it is
     recommended to use the PKCS‘8’ form as it can handle all key types,
     and can store additional parameters such as the seed, in case of
     provable RSA or DSA keys.  Generated keys can be exported in memory
     using ‘gnutls_privkey_export_x509()’ , and then with
     ‘gnutls_x509_privkey_export2_pkcs8()’ .

     If key generation is part of your application, avoid setting the
     number of bits directly, and instead use
     ‘gnutls_sec_param_to_pk_bits()’ .  That way the generated keys will
     adapt to the security levels of the underlying GnuTLS library.

     *Returns:* On success, ‘GNUTLS_E_SUCCESS’ (0) is returned,
     otherwise a negative error value.

     *Since:* 3.5.0