/********************************* (C) РОТЕК ***********************************
 * @module  cert_req
 * @file    cert_req.c
 * @version 1.0.0
 * @date    XX.XX.XXXX
 *******************************************************************************
 * @history     Version  Author         Comment
 * XX.XX.XXXX   1.0.0    Telenkov D.A.  First release.
 *******************************************************************************
 */
#include "cert_req.h"

#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif

#include "mbedtls/platform.h"

#include "mbedtls/x509_csr.h"
#include "mbedtls/entropy.h"
#include "mbedtls/ctr_drbg.h"
#include "mbedtls/error.h"
#include "mbedtls/certs.h"


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

#define DFL_FILENAME            "keyfile.key"
#define DFL_DEBUG_LEVEL         0
#define DFL_OUTPUT_FILENAME     "cert.req"
#define DFL_SUBJECT_NAME        "CN=Cert,O=mbed TLS,C=UK" // Надо CN - ip, O - VimpelCom, C=RU
#define DFL_KEY_USAGE           0
#define DFL_NS_CERT_TYPE        0

/*
 * global options
 */
struct options
{
    const char *filename;       /* filename of the key file             */
    int debug_level;            /* level of debugging                   */
    const char *output_file;    /* where to store the constructed key file  */
    const char *subject_name;   /* subject name for certificate request */
    unsigned char key_usage;    /* key usage flags                      */
    unsigned char ns_cert_type; /* NS cert type                         */
} opt;

static int write_certificate_request( mbedtls_x509write_csr *req, const char *output_file,
                               int (*f_rng)(void *, unsigned char *, size_t),
                               void *p_rng );

unsigned char output_buf[4096];

void SSL_Test()
{
    int ret = 0;
    mbedtls_pk_context key;
    char buf[1024];
    mbedtls_x509write_csr req;
    mbedtls_entropy_context entropy;
    mbedtls_ctr_drbg_context ctr_drbg;
    const char *pers = "csr example app";
    

    // Set to sane values
    mbedtls_x509write_csr_init( &req );
    mbedtls_x509write_csr_set_md_alg( &req, MBEDTLS_MD_SHA256 );
    mbedtls_pk_init( &key );
    mbedtls_ctr_drbg_init( &ctr_drbg );
    memset( buf, 0, sizeof( buf ) );
    
    // default
    opt.filename            = DFL_FILENAME;
    opt.debug_level         = DFL_DEBUG_LEVEL;
    opt.output_file         = DFL_OUTPUT_FILENAME;
    opt.subject_name        = DFL_SUBJECT_NAME;
    opt.key_usage           = DFL_KEY_USAGE;
    opt.ns_cert_type        = DFL_NS_CERT_TYPE;
    
    // user
    opt.key_usage |= MBEDTLS_X509_KU_KEY_AGREEMENT;
    opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_SSL_CA;
    
    if( opt.key_usage )
        mbedtls_x509write_csr_set_key_usage( &req, opt.key_usage );

    if( opt.ns_cert_type )
        mbedtls_x509write_csr_set_ns_cert_type( &req, opt.ns_cert_type );
    

    // 0. Seed the PRNG
    mbedtls_printf( "  . Seeding the random number generator..." );
    fflush( stdout );

    mbedtls_entropy_init( &entropy );
    if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func, &entropy,
                               (const unsigned char *) pers,
                               strlen( pers ) ) ) != 0 )
    {
        mbedtls_printf( " failed\r\n  !  mbedtls_ctr_drbg_seed returned %d", ret );
        goto exit;
    }

    mbedtls_printf( " ok\r\n" );
    
    // 1.0. Check the subject name for validity
    mbedtls_printf( "  . Checking subject name..." );
    fflush( stdout );

    if( ( ret = mbedtls_x509write_csr_set_subject_name( &req, opt.subject_name ) ) != 0 )
    {
        mbedtls_printf( " failed\r\n  !  mbedtls_x509write_csr_set_subject_name returned %d", ret );
        goto exit;
    }

    mbedtls_printf( " ok\r\n" );
    
    // 1.1. Load the key
    mbedtls_printf( "  . Loading the private key ..." );
    fflush( stdout );

    //ret = mbedtls_pk_parse_keyfile( &key, opt.filename, NULL );
    ret =  mbedtls_pk_parse_key( &key, (const unsigned char *) mbedtls_test_srv_key, mbedtls_test_srv_key_len, NULL, 0 );
    
    
    
    if( ret != 0 )
    {
        mbedtls_printf( " failed\r\n  !  mbedtls_pk_parse_keyfile returned %d", ret );
        goto exit;
    }

    mbedtls_x509write_csr_set_key( &req, &key );

    mbedtls_printf( " ok\r\n" );
        
    // 1.2. Writing the request
    mbedtls_printf( "  . Writing the certificate request ..." );
   
    //if( ( ret = write_certificate_request( &req, opt.output_file, mbedtls_ctr_drbg_random, &ctr_drbg ) ) != 0 )
    ret = mbedtls_x509write_csr_pem( &req, output_buf, 4096, mbedtls_ctr_drbg_random, &ctr_drbg );
    if (ret != 0)
    {
        mbedtls_printf( " failed\r\n  !  write_certifcate_request %d", ret );
        goto exit;
    }

    mbedtls_printf( " ok\r\n" );
    
    
exit:

    if( ret != 0 && ret != 1)
    {
        mbedtls_printf("\r\n");
    }

    mbedtls_x509write_csr_free( &req );
    mbedtls_pk_free( &key );
    mbedtls_ctr_drbg_free( &ctr_drbg );
    mbedtls_entropy_free( &entropy );    
}

//
static int write_certificate_request( mbedtls_x509write_csr *req, const char *output_file,
                               int (*f_rng)(void *, unsigned char *, size_t),
                               void *p_rng )
{
/*  
    int ret;
    FILE *f;
    unsigned char output_buf[4096];
    size_t len = 0;

    memset( output_buf, 0, 4096 );
    if( ( ret = mbedtls_x509write_csr_pem( req, output_buf, 4096, f_rng, p_rng ) ) < 0 )
        return( ret );

    len = strlen( (char *) output_buf );

    if( ( f = fopen( output_file, "w" ) ) == NULL )
        return( -1 );

    if( fwrite( output_buf, 1, len, f ) != len )
    {
        fclose( f );
        return( -1 );
    }

    fclose( f );
*/
    return( 0 );
}

/********************************* (C) РОТЕК **********************************/