#include <openssl/evp.h> int EVP_PKEY_encapsulate_init(EVP_PKEY_CTX *ctx, const OSSL_PARAM params[]); int EVP_PKEY_encapsulate(EVP_PKEY_CTX *ctx, unsigned char *wrappedkey, size_t *wrappedkeylen, unsigned char *genkey, size_t *genkeylen);
The EVP_PKEY_encapsulate() function performs a public key encapsulation operation using ctx. The symmetric secret generated in genkey can be used as key material. The ciphertext in wrappedkey is its encapsulated form, which can be sent to another party, who can use EVP_PKEY_decapsulate(3) to retrieve it using their private key. If wrappedkey is NULL then the maximum size of the output buffer is written to the *wrappedkeylen parameter unless wrappedkeylen is NULL and the maximum size of the generated key buffer is written to *genkeylen unless genkeylen is NULL. If wrappedkey is not NULL and the call is successful then the internally generated key is written to genkey and its size is written to *genkeylen. The encapsulated version of the generated key is written to wrappedkey and its size is written to *wrappedkeylen.
#include <openssl/evp.h> /* * NB: assumes rsa_pub_key is an public key of another party. */ EVP_PKEY_CTX *ctx = NULL; size_t secretlen = 0, outlen = 0; unsigned char *out = NULL, *secret = NULL; ctx = EVP_PKEY_CTX_new_from_pkey(libctx, rsa_pub_key, NULL); if (ctx = NULL) /* Error */ if (EVP_PKEY_encapsulate_init(ctx, NULL) <= 0) /* Error */ /* Set the mode - only 'RSASVE' is currently supported */ if (EVP_PKEY_CTX_set_kem_op(ctx, "RSASVE") <= 0) /* Error */ /* Determine buffer length */ if (EVP_PKEY_encapsulate(ctx, NULL, &outlen, NULL, &secretlen) <= 0) /* Error */ out = OPENSSL_malloc(outlen); secret = OPENSSL_malloc(secretlen); if (out == NULL || secret == NULL) /* malloc failure */ /* * The generated 'secret' can be used as key material. * The encapsulated 'out' can be sent to another party who can * decapsulate it using their private key to retrieve the 'secret'. */ if (EVP_PKEY_encapsulate(ctx, out, &outlen, secret, &secretlen) <= 0) /* Error */
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>.