NAME

EVP_PKEY_CTX_new, EVP_PKEY_CTX_new_id, EVP_PKEY_CTX_new_from_name, EVP_PKEY_CTX_new_from_pkey, EVP_PKEY_CTX_dup, EVP_PKEY_CTX_free - public key algorithm context functions

SYNOPSIS

 #include <openssl/evp.h>
 
 EVP_PKEY_CTX *EVP_PKEY_CTX_new(EVP_PKEY *pkey, ENGINE *e);
 EVP_PKEY_CTX *EVP_PKEY_CTX_new_id(int id, ENGINE *e);
 EVP_PKEY_CTX *EVP_PKEY_CTX_new_from_name(OPENSSL_CTX *libctx,
                                          const char *name,
                                          const char *propquery);
 EVP_PKEY_CTX *EVP_PKEY_CTX_new_from_pkey(OPENSSL_CTX *libctx,
                                          EVP_PKEY *pkey);
 EVP_PKEY_CTX *EVP_PKEY_CTX_dup(const EVP_PKEY_CTX *ctx);
 void EVP_PKEY_CTX_free(EVP_PKEY_CTX *ctx);

DESCRIPTION

The EVP_PKEY_CTX_new() function allocates public key algorithm context using the pkey key type and ENGINE e.

The EVP_PKEY_CTX_new_id() function allocates public key algorithm context using the key type specified by id and ENGINE e.

The EVP_PKEY_CTX_new_from_name() function allocates a public key algorithm context using the library context libctx (see "NOTES" below.

The EVP_PKEY_CTX_new_from_pkey() function allocates a public key algorithm context using the library context libctx (see NOTES

On EVP_PKEY_CTX

The EVP_PKEY_CTX structure is an opaque public key algorithm context used by the OpenSSL high level public key API. Contexts MUST NOT be shared between threads: that is it is not permissible to use the same context simultaneously in two threads.

On Key Types

We mention "key type" in this manual, which is the same as "algorithm" in most cases, allowing either term to be used interchangeably. There are algorithms where the key type and the algorithm of the operations that use the keys are not the same, such as EC keys being used for ECDSA and ECDH operations.

Key types are given in two different manners:

Legacy NID or EVP_PKEY type

This is the id used with EVP_PKEY_CTX_new_id().

These are EVP_PKEY_RSA, EVP_PKEY_RSA_PSS, EVP_PKEY_DSA, EVP_PKEY_DH, EVP_PKEY_EC, EVP_PKEY_SM2, EVP_PKEY_X25519, EVP_PKEY_X448, and are used by legacy methods.

Name strings

This is the name used with EVP_PKEY_CTX_new_from_name().

These are names like "RSA", "DSA", and what's available depends on what providers are currently accessible.

The OpenSSL providers offer a set of key types available this way, please see OSSL_PROVIDER-default(7) and related documentation for more information.

RETURN VALUES

EVP_PKEY_CTX_new(), EVP_PKEY_CTX_new_id(), EVP_PKEY_CTX_dup() returns either the newly allocated EVP_PKEY_CTX structure of NULL if an error occurred.

EVP_PKEY_CTX_free() does not return a value.

COPYRIGHT

Licensed under the Apache License 2.0 (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.

OpenSSL.vip

Cryptography and SSL/TLS Toolkit