NAME¶

EVP_PKEY_CTX_ctrl, EVP_PKEY_CTX_ctrl_str, EVP_PKEY_CTX_set_signature_md, EVP_PKEY_CTX_get_signature_md, EVP_PKEY_CTX_set_dsa_paramgen_bits, EVP_PKEY_CTX_set_dh_paramgen_prime_len, EVP_PKEY_CTX_set_dh_paramgen_generator, EVP_PKEY_CTX_set_ec_paramgen_curve_nid, EVP_PKEY_CTX_set_ec_param_enc, EVP_PKEY_CTX_set_ecdh_cofactor_mode, EVP_PKEY_CTX_get_ecdh_cofactor_mode, EVP_PKEY_CTX_set_ecdh_kdf_type, EVP_PKEY_CTX_get_ecdh_kdf_type, EVP_PKEY_CTX_set_ecdh_kdf_md, EVP_PKEY_CTX_get_ecdh_kdf_md, EVP_PKEY_CTX_set_ecdh_kdf_outlen, EVP_PKEY_CTX_get_ecdh_kdf_outlen, EVP_PKEY_CTX_set0_ecdh_kdf_ukm, EVP_PKEY_CTX_get0_ecdh_kdf_ukm, EVP_PKEY_CTX_set1_id, EVP_PKEY_CTX_get1_id, EVP_PKEY_CTX_get1_id_len — algorithm specific control operations

SYNOPSIS¶

#include <openssl/evp.h>

int
EVP_PKEY_CTX_ctrl(EVP_PKEY_CTX *ctx, int keytype, int optype, int cmd, int p1, void *p2);

int
EVP_PKEY_CTX_ctrl_str(EVP_PKEY_CTX *ctx, const char *type, const char *value);

int
EVP_PKEY_CTX_set_signature_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);

int
EVP_PKEY_CTX_get_signature_md(EVP_PKEY_CTX *ctx, const EVP_MD **pmd);

#include <openssl/dsa.h>

int
EVP_PKEY_CTX_set_dsa_paramgen_bits(EVP_PKEY_CTX *ctx, int nbits);

#include <openssl/dh.h>

int
EVP_PKEY_CTX_set_dh_paramgen_prime_len(EVP_PKEY_CTX *ctx, int len);

int
EVP_PKEY_CTX_set_dh_paramgen_generator(EVP_PKEY_CTX *ctx, int gen);

#include <openssl/ec.h>

int
EVP_PKEY_CTX_set_ec_paramgen_curve_nid(EVP_PKEY_CTX *ctx, int nid); int
EVP_PKEY_CTX_set_ec_param_enc(EVP_PKEY_CTX *ctx, int param_enc);

int
EVP_PKEY_CTX_set_ecdh_cofactor_mode(EVP_PKEY_CTX *ctx, int cofactor_mode);

int
EVP_PKEY_CTX_get_ecdh_cofactor_mode(EVP_PKEY_CTX *ctx);

int
EVP_PKEY_CTX_set_ecdh_kdf_type(EVP_PKEY_CTX *ctx, int kdf);

int
EVP_PKEY_CTX_get_ecdh_kdf_type(EVP_PKEY_CTX *ctx);

int
EVP_PKEY_CTX_set_ecdh_kdf_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);

int
EVP_PKEY_CTX_get_ecdh_kdf_md(EVP_PKEY_CTX *ctx, const EVP_MD **pmd);

int
EVP_PKEY_CTX_set_ecdh_kdf_outlen(EVP_PKEY_CTX *ctx, int len);

int
EVP_PKEY_CTX_get_ecdh_kdf_outlen(EVP_PKEY_CTX *ctx, int *plen);

int
EVP_PKEY_CTX_set0_ecdh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char *ukm, int len);

int
EVP_PKEY_CTX_get0_ecdh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char **pukm);

int
EVP_PKEY_CTX_set1_id(EVP_PKEY_CTX *ctx, void *id, size_t id_len);

int
EVP_PKEY_CTX_get1_id(EVP_PKEY_CTX *ctx, void *id);

int
EVP_PKEY_CTX_get1_id_len(EVP_PKEY_CTX *ctx, size_t *pid_len);

DESCRIPTION¶

The function EVP_PKEY_CTX_ctrl() sends a control operation to the context ctx. The key type used must match keytype if it is not -1. The parameter optype is a mask indicating which operations the control can be applied to. The control command is indicated in cmd and any additional arguments in p1 and p2.

Applications will not normally call EVP_PKEY_CTX_ctrl() directly but will instead call one of the algorithm specific macros described below and in RSA_pkey_ctx_ctrl(3).

The function EVP_PKEY_CTX_ctrl_str() allows an application to send an algorithm specific control operation to a context ctx in string form. This is intended to be used for options specified on the command line or in text files. The commands supported are documented in the openssl(1) utility command line pages for the option -pkeyopt which is supported by the pkeyutl, genpkey, and req commands.

All the remaining "functions" are implemented as macros.

The EVP_PKEY_CTX_set_signature_md() and EVP_PKEY_CTX_get_signature_md() macros set and get the message digest type used in a signature. They can be used with the RSA, DSA, and ECDSA algorithms. If the key is of the type EVP_PKEY_RSA_PSS and has usage restrictions, an error occurs if an attempt is made to set the digest to anything other than the restricted value.

These two macros expand to EVP_PKEY_CTX_ctrl() with an optype of EVP_PKEY_OP_TYPE_SIG and the following command arguments:

RETURN VALUES¶

EVP_PKEY_CTX_ctrl() and its macros return a positive value for success and 0 or a negative value for failure. In particular, a return value of -2 indicates the operation is not supported by the public key algorithm.

SEE ALSO¶

DH_new(3), EVP_DigestInit(3), EVP_PKEY_CTX_new(3), EVP_PKEY_decrypt(3), EVP_PKEY_derive(3), EVP_PKEY_encrypt(3), EVP_PKEY_get_default_digest_nid(3), EVP_PKEY_keygen(3), EVP_PKEY_meth_set_ctrl(3), EVP_PKEY_sign(3), EVP_PKEY_verify(3), EVP_PKEY_verify_recover(3), RSA_pkey_ctx_ctrl(3)

HISTORY¶

The functions EVP_PKEY_CTX_ctrl(), EVP_PKEY_CTX_ctrl_str(), EVP_PKEY_CTX_set_signature_md(), EVP_PKEY_CTX_set_dsa_paramgen_bits(), EVP_PKEY_CTX_set_dh_paramgen_prime_len(), EVP_PKEY_CTX_set_dh_paramgen_generator(), and EVP_PKEY_CTX_set_ec_paramgen_curve_nid() first appeared in OpenSSL 1.0.0 and have been available since OpenBSD 4.9.

The functions EVP_PKEY_CTX_get_signature_md(), EVP_PKEY_CTX_set_ec_param_enc(), EVP_PKEY_CTX_set_ecdh_cofactor_mode(), EVP_PKEY_CTX_get_ecdh_cofactor_mode(), EVP_PKEY_CTX_set_ecdh_kdf_type(), EVP_PKEY_CTX_get_ecdh_kdf_type(), EVP_PKEY_CTX_set_ecdh_kdf_md(), EVP_PKEY_CTX_get_ecdh_kdf_md(), EVP_PKEY_CTX_set_ecdh_kdf_outlen(), EVP_PKEY_CTX_get_ecdh_kdf_outlen(), EVP_PKEY_CTX_set0_ecdh_kdf_ukm(), and EVP_PKEY_CTX_get0_ecdh_kdf_ukm() first appeared in OpenSSL 1.0.2 and have been available since OpenBSD 6.6.

The functions EVP_PKEY_CTX_set1_id(), EVP_PKEY_CTX_get1_id(), and EVP_PKEY_CTX_get1_id_len() first appeared in OpenSSL 1.1.1 and have been available since OpenBSD 6.6.