Example Code for Using KAE

When you need to use the C language to invoke KAE, you can use the ENGINE_by_id function to obtain the KAE handle and then enable the corresponding algorithm. This section provides code for reference only. Modify the code as required.

#include <stdio.h>
#include <stdlib.h>

/* OpenSSL headers */
#include <openssl/bio.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/engine.h>
 
int main(int argc, char **argv)
{
    /* Initializing OpenSSL */
    SSL_load_error_strings();
    ERR_load_BIO_strings();
    OpenSSL_add_all_algorithms();
    
    /*You can use ENGINE_by_id Function to get the handle of the Huawei Accelerator Engine*/
    ENGINE *e = ENGINE_by_id("kae");
    /*Enable the KAE asynchronization function. This parameter is optional. The value 0 indicates disabled, and the value 1 (default) indicates enabled. */
    ENGINE_ctrl_cmd_string(e, "KAE_CMD_ENABLE_ASYNC", "1", 0);
    ENGINE_init(e);
    /*Specify KAE for RSA-based encryption and decryption. If ENGINE_set_default_RSA(ENGINE *e) is used during initialization, e does not need to be transferred.*/
    RSA *rsa = RSA_new_method(e);
    /*The user code*/
...
    
    ENGINE_free(e);
    
}

You can also specify KAE for the crypto algorithm during initialization (other algorithms do not require KAE). In this way, the code modification workload is reduced.

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int ENGINE_set_default_RSA(ENGINE *e); 
int ENGINE_set_default_DH(ENGINE *e);
int ENGINE_set_default_ciphers(ENGINE *e);
int ENGINE_set_default_digests(ENGINE *e);
int ENGINE_set_default(ENGINE *e, unsigned int flags);

For details about how to use APIs, visit the official OpenSSL website.