NAME

EVP_KEM_fetch, EVP_KEM_free, EVP_KEM_up_ref, EVP_KEM_number, EVP_KEM_is_a, EVP_KEM_provider, EVP_KEM_do_all_provided, EVP_KEM_names_do_all, EVP_KEM_gettable_ctx_params, EVP_KEM_settable_ctx_params - Functions to manage EVP_KEM algorithm objects

SYNOPSIS

 #include <openssl/evp.h>

 EVP_KEM *EVP_KEM_fetch(OSSL_LIB_CTX *ctx, const char *algorithm,
                        const char *properties);
 void EVP_KEM_free(EVP_KEM *kem);
 int EVP_KEM_up_ref(EVP_KEM *kem);
 int EVP_KEM_number(const EVP_KEM *kem);
 int EVP_KEM_is_a(const EVP_KEM *kem, const char *name);
 OSSL_PROVIDER *EVP_KEM_provider(const EVP_KEM *kem);
 void EVP_KEM_do_all_provided(OSSL_LIB_CTX *libctx,
                              void (*fn)(EVP_KEM *kem, void *arg), void *arg);
 void EVP_KEM_names_do_all(const EVP_KEM *kem,
                           void (*fn)(const char *name, void *data), void *data);
 const OSSL_PARAM *EVP_KEM_gettable_ctx_params(const EVP_KEM *kem);
 const OSSL_PARAM *EVP_KEM_settable_ctx_params(const EVP_KEM *kem);

DESCRIPTION

EVP_KEM_fetch() fetches the implementation for the given algorithm from any provider offering it, within the criteria given by the properties and in the scope of the given library context ctx (see OSSL_LIB_CTX(3)). The algorithm will be one offering functions for performing asymmetric kem related tasks such as key encapsulation and decapsulation. See "Fetching algorithms" in provider(7) for further information.

The returned value must eventually be freed with EVP_KEM_free().

EVP_KEM_free() decrements the reference count for the EVP_KEM structure. Typically this structure will have been obtained from an earlier call to EVP_KEM_fetch(). If the reference count drops to 0 then the structure is freed.

EVP_KEM_up_ref() increments the reference count for an EVP_KEM structure.

EVP_KEM_is_a() returns 1 if kem is an implementation of an algorithm that's identifiable with name, otherwise 0.

EVP_KEM_provider() returns the provider that kem was fetched from.

EVP_KEM_do_all_provided() traverses all EVP_KEMs implemented by all activated providers in the given library context libctx, and for each of the implementations, calls the given function fn with the implementation method and the given arg as argument.

EVP_KEM_number() returns the internal dynamic number assigned to kem.

EVP_KEM_names_do_all() traverses all names for kem, and calls fn with each name and data.

EVP_KEM_gettable_ctx_params() and EVP_KEM_settable_ctx_params() return a constant OSSL_PARAM array that describes the names and types of key parameters that can be retrieved or set by a key encapsulation algorithm using EVP_PKEY_CTX_get_params(3) and EVP_PKEY_CTX_set_params(3).

RETURN VALUES

EVP_KEM_fetch() returns a pointer to an EVP_KEM for success or NULL for failure.

EVP_KEM_up_ref() returns 1 for success or 0 otherwise.

EVP_KEM_gettable_ctx_params() and EVP_KEM_settable_ctx_params() return a constant OSSL_PARAM array or NULL on error.

HISTORY

The functions described here were added in OpenSSL 3.0.

COPYRIGHT