static int rsa_encrypt_wrap( void *ctx,
const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen, size_t osize,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
{
*olen = ((mbedtls_rsa_context *) ctx)->len;
if( *olen > osize )
return( MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE );
return( mbedtls_rsa_pkcs1_encrypt( (mbedtls_rsa_context *) ctx,
f_rng, p_rng, MBEDTLS_RSA_PUBLIC, ilen, input, output ) );
}
int ciphertext_from_nonce_and_id(const unsigned char *nonce,
const unsigned char *id,
const unsigned char *pubkey,
unsigned char *ciphertext)
{
unsigned char plaintext[52];
memcpy(plaintext, nonce, 40);
memcpy(plaintext + 40, id, 12);
rsa_context rsa;
init_rsa_context_with_public_key(&rsa, pubkey);
#ifdef USE_MBEDTLS
int ret = mbedtls_rsa_pkcs1_encrypt(&rsa, mbedtls_default_rng, nullptr, MBEDTLS_RSA_PUBLIC, 52, plaintext, ciphertext);
#else
int ret = rsa_pkcs1_encrypt(&rsa, RSA_PUBLIC, 52, plaintext, ciphertext);
#endif
rsa_free(&rsa);
return ret;
}
int rsaencrypt_main( int argc, char *argv[] )
{
FILE *f;
int ret;
size_t i;
mbedtls_rsa_context rsa;
mbedtls_entropy_context entropy;
mbedtls_ctr_drbg_context ctr_drbg;
unsigned char input[1024];
unsigned char buf[512];
const char *pers = "rsa_encrypt";
mbedtls_ctr_drbg_init( &ctr_drbg );
ret = 1;
if( argc != 2 )
{
mbedtls_printf( "usage: rsa_encrypt <string of max 100 characters>\n" );
#if defined(_WIN32)
mbedtls_printf( "\n" );
#endif
goto exit;
}
mbedtls_printf( "\n . 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\n ! mbedtls_ctr_drbg_seed returned %d\n", ret );
goto exit;
}
mbedtls_printf( "\n . Reading public key from rsa_pub.txt" );
fflush( stdout );
if( ( f = fopen( "rsa_pub.txt", "rb" ) ) == NULL )
{
ret = 1;
mbedtls_printf( " failed\n ! Could not open rsa_pub.txt\n" \
" ! Please run rsa_genkey first\n\n" );
goto exit;
}
mbedtls_rsa_init( &rsa, MBEDTLS_RSA_PKCS_V15, 0 );
if( ( ret = mbedtls_mpi_read_file( &rsa.N, 16, f ) ) != 0 ||
( ret = mbedtls_mpi_read_file( &rsa.E, 16, f ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_mpi_read_file returned %d\n\n", ret );
goto exit;
}
rsa.len = ( mbedtls_mpi_bitlen( &rsa.N ) + 7 ) >> 3;
fclose( f );
if( strlen( argv[1] ) > 100 )
{
mbedtls_printf( " Input data larger than 100 characters.\n\n" );
goto exit;
}
memcpy( input, argv[1], strlen( argv[1] ) );
/*
* Calculate the RSA encryption of the hash.
*/
mbedtls_printf( "\n . Generating the RSA encrypted value" );
fflush( stdout );
if( ( ret = mbedtls_rsa_pkcs1_encrypt( &rsa, mbedtls_ctr_drbg_random, &ctr_drbg,
MBEDTLS_RSA_PUBLIC, strlen( argv[1] ),
input, buf ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_rsa_pkcs1_encrypt returned %d\n\n", ret );
goto exit;
}
/*
* Write the signature into result-enc.txt
*/
if( ( f = fopen( "result-enc.txt", "wb+" ) ) == NULL )
{
ret = 1;
mbedtls_printf( " failed\n ! Could not create %s\n\n", "result-enc.txt" );
goto exit;
}
for( i = 0; i < rsa.len; i++ )
mbedtls_fprintf( f, "%02X%s", buf[i],
( i + 1 ) % 16 == 0 ? "\r\n" : " " );
fclose( f );
mbedtls_printf( "\n . Done (created \"%s\")\n\n", "result-enc.txt" );
exit:
mbedtls_ctr_drbg_free( &ctr_drbg );
mbedtls_entropy_free( &entropy );
#if defined(_WIN32)
mbedtls_printf( " + Press Enter to exit this program.\n" );
fflush( stdout ); getchar();
#endif
return( ret );
}
