void entropy_init( entropy_context *ctx )
{
memset( ctx, 0, sizeof(entropy_context) );
#if defined(POLARSSL_THREADING_C)
polarssl_mutex_init( &ctx->mutex );
#endif
#if defined(POLARSSL_ENTROPY_SHA512_ACCUMULATOR)
sha512_starts( &ctx->accumulator, 0 );
#else
sha256_starts( &ctx->accumulator, 0 );
#endif
#if defined(POLARSSL_HAVEGE_C)
havege_init( &ctx->havege_data );
#endif
#if !defined(POLARSSL_NO_DEFAULT_ENTROPY_SOURCES)
#if !defined(POLARSSL_NO_PLATFORM_ENTROPY)
entropy_add_source( ctx, platform_entropy_poll, NULL,
ENTROPY_MIN_PLATFORM );
#endif
#if defined(POLARSSL_TIMING_C)
entropy_add_source( ctx, hardclock_poll, NULL, ENTROPY_MIN_HARDCLOCK );
#endif
#if defined(POLARSSL_HAVEGE_C)
entropy_add_source( ctx, havege_poll, &ctx->havege_data,
ENTROPY_MIN_HAVEGE );
#endif
#endif /* POLARSSL_NO_DEFAULT_ENTROPY_SOURCES */
}
void rand_ctx_init_platform_entropy(int min_size, bool use_urandom)
{
static bool platform_set = false;
if (!platform_set)
{
ctr_drbg_context *cd_ctx = rand_ctx_get();
entropy_context *ec = cd_ctx->p_entropy;
f_source_ptr f_source = platform_entropy_poll;
ASSERT(NULL != ec);
#ifndef WIN32
if (use_urandom)
f_source = urandom_entropy_poll;
#endif
if (0 != entropy_add_source(ec, f_source, NULL, min_size))
msg (M_FATAL, "Failed to add platform source to entropy pool");
if (!rand_ctx_reseed())
msg (M_FATAL, "ERROR: Random number generator failed to obtain entropy to reseed");
platform_set = true;
}
}
int init_random(void) {
/* Initialize the rng */
entropy_init(&entropy);
entropy_add_source(&entropy, tpm_entropy_source, NULL, 0);
entropy_gather(&entropy);
ctr_drbg_init(&ctr_drbg, entropy_func, &entropy, NULL, 0);
ctr_drbg_set_prediction_resistance( &ctr_drbg, CTR_DRBG_PR_OFF );
return 0;
}
/*
* Initialise the given ctr_drbg context, using a personalisation string and an
* entropy gathering function.
*/
ctr_drbg_context * rand_ctx_get()
{
static havege_state hs = {0};
static entropy_context ec = {0};
static ctr_drbg_context cd_ctx = {0};
static bool rand_initialised = false;
if (!rand_initialised)
{
struct gc_arena gc = gc_new();
struct buffer pers_string = alloc_buf_gc(100, &gc);
/*
* Personalisation string, should be as unique as possible (see NIST
* 800-90 section 8.7.1). We have very little information at this stage.
* Include Program Name, memory address of the context and PID.
*/
buf_printf(&pers_string, "OpenVPN %0u %p %s", platform_getpid(), &cd_ctx, time_string(0, 0, 0, &gc));
/* Initialise PolarSSL RNG, and built-in entropy sources */
havege_init(&hs);
entropy_init(&ec);
if (0 != entropy_add_source(&ec, hardclock_poll, NULL, ENTROPY_MIN_HARDCLOCK))
msg (M_FATAL, "Failed to add hardclock to entropy pool");
if (0 != entropy_add_source(&ec, havege_poll, &hs, ENTROPY_MIN_HAVEGE))
msg (M_FATAL, "Failed to add havege to entropy pool");
if (0 != ctr_drbg_init(&cd_ctx, entropy_func, &ec, BPTR(&pers_string), BLEN(&pers_string)))
msg (M_FATAL, "Failed to initialize random generator");
gc_free(&gc);
rand_initialised = true;
}
return &cd_ctx;
}
/*
* The actual entropy quality is hard to test, but we can at least
* test that the functions don't cause errors and write the correct
* amount of data to buffers.
*/
int entropy_self_test( int verbose )
{
int ret = 0;
entropy_context ctx;
unsigned char buf[ENTROPY_BLOCK_SIZE] = { 0 };
unsigned char acc[ENTROPY_BLOCK_SIZE] = { 0 };
size_t i, j;
if( verbose != 0 )
polarssl_printf( " ENTROPY test: " );
entropy_init( &ctx );
ret = entropy_add_source( &ctx, entropy_dummy_source, NULL, 16 );
if( ret != 0 )
goto cleanup;
if( ( ret = entropy_gather( &ctx ) ) != 0 )
goto cleanup;
if( ( ret = entropy_update_manual( &ctx, buf, sizeof buf ) ) != 0 )
goto cleanup;
/*
* To test that entropy_func writes correct number of bytes:
* - use the whole buffer and rely on ASan to detect overruns
* - collect entropy 8 times and OR the result in an accumulator:
* any byte should then be 0 with probably 2^(-64), so requiring
* each of the 32 or 64 bytes to be non-zero has a false failure rate
* of at most 2^(-58) which is acceptable.
*/
for( i = 0; i < 8; i++ )
{
if( ( ret = entropy_func( &ctx, buf, sizeof( buf ) ) ) != 0 )
goto cleanup;
for( j = 0; j < sizeof( buf ); j++ )
acc[j] |= buf[j];
}
for( j = 0; j < sizeof( buf ); j++ )
{
if( acc[j] == 0 )
{
ret = 1;
goto cleanup;
}
}
cleanup:
entropy_free( &ctx );
if( verbose != 0 )
{
if( ret != 0 )
polarssl_printf( "failed\n" );
else
polarssl_printf( "passed\n" );
polarssl_printf( "\n" );
}
return( ret != 0 );
}
int main( int argc, char *argv[] )
{
int ret = 0;
pk_context key;
char buf[1024];
int i;
char *p, *q;
entropy_context entropy;
ctr_drbg_context ctr_drbg;
const char *pers = "gen_key";
#if defined(POLARSSL_ECP_C)
const ecp_curve_info *curve_info;
#endif
/*
* Set to sane values
*/
pk_init( &key );
memset( buf, 0, sizeof( buf ) );
if( argc == 0 )
{
usage:
ret = 1;
printf( USAGE );
#if defined(POLARSSL_ECP_C)
printf( " availabled ec_curve values:\n" );
curve_info = ecp_curve_list();
printf( " %s (default)\n", curve_info->name );
while( ( ++curve_info )->name != NULL )
printf( " %s\n", curve_info->name );
#endif
goto exit;
}
opt.type = DFL_TYPE;
opt.rsa_keysize = DFL_RSA_KEYSIZE;
opt.ec_curve = DFL_EC_CURVE;
opt.filename = DFL_FILENAME;
opt.format = DFL_FORMAT;
opt.use_dev_random = DFL_USE_DEV_RANDOM;
for( i = 1; i < argc; i++ )
{
p = argv[i];
if( ( q = strchr( p, '=' ) ) == NULL )
goto usage;
*q++ = '\0';
if( strcmp( p, "type" ) == 0 )
{
if( strcmp( q, "rsa" ) == 0 )
opt.type = POLARSSL_PK_RSA;
else if( strcmp( q, "ec" ) == 0 )
opt.type = POLARSSL_PK_ECKEY;
else
goto usage;
}
else if( strcmp( p, "format" ) == 0 )
{
if( strcmp( q, "pem" ) == 0 )
opt.format = FORMAT_PEM;
else if( strcmp( q, "der" ) == 0 )
opt.format = FORMAT_DER;
else
goto usage;
}
else if( strcmp( p, "rsa_keysize" ) == 0 )
{
opt.rsa_keysize = atoi( q );
if( opt.rsa_keysize < 1024 || opt.rsa_keysize > 8192 )
goto usage;
}
else if( strcmp( p, "ec_curve" ) == 0 )
{
if( ( curve_info = ecp_curve_info_from_name( q ) ) == NULL )
goto usage;
opt.ec_curve = curve_info->grp_id;
}
else if( strcmp( p, "filename" ) == 0 )
opt.filename = q;
else if( strcmp( p, "use_dev_random" ) == 0 )
{
opt.use_dev_random = atoi( q );
if( opt.use_dev_random < 0 || opt.use_dev_random > 1 )
goto usage;
}
else
goto usage;
}
printf( "\n . Seeding the random number generator..." );
fflush( stdout );
entropy_init( &entropy );
#if !defined(_WIN32) && defined(POLARSSL_FS_IO)
if( opt.use_dev_random )
{
if( ( ret = entropy_add_source( &entropy, dev_random_entropy_poll,
NULL, DEV_RANDOM_THRESHOLD ) ) != 0 )
{
printf( " failed\n ! entropy_add_source returned -0x%04x\n", -ret );
goto exit;
}
printf("\n Using /dev/random, so can take a long time! " );
fflush( stdout );
}
#endif /* !_WIN32 && POLARSSL_FS_IO */
if( ( ret = ctr_drbg_init( &ctr_drbg, entropy_func, &entropy,
(const unsigned char *) pers,
strlen( pers ) ) ) != 0 )
{
printf( " failed\n ! ctr_drbg_init returned -0x%04x\n", -ret );
goto exit;
}
/*
* 1.1. Generate the key
*/
printf( "\n . Generating the private key ..." );
fflush( stdout );
if( ( ret = pk_init_ctx( &key, pk_info_from_type( opt.type ) ) ) != 0 )
{
printf( " failed\n ! pk_init_ctx returned -0x%04x", -ret );
goto exit;
}
#if defined(POLARSSL_RSA_C) && defined(POLARSSL_GENPRIME)
if( opt.type == POLARSSL_PK_RSA )
{
ret = rsa_gen_key( pk_rsa( key ), ctr_drbg_random, &ctr_drbg,
opt.rsa_keysize, 65537 );
if( ret != 0 )
{
printf( " failed\n ! rsa_gen_key returned -0x%04x", -ret );
goto exit;
}
}
else
#endif /* POLARSSL_RSA_C */
#if defined(POLARSSL_ECP_C)
if( opt.type == POLARSSL_PK_ECKEY )
{
ret = ecp_gen_key( opt.ec_curve, pk_ec( key ),
ctr_drbg_random, &ctr_drbg );
if( ret != 0 )
{
printf( " failed\n ! rsa_gen_key returned -0x%04x", -ret );
goto exit;
}
}
else
#endif /* POLARSSL_ECP_C */
{
printf( " failed\n ! key type not supported\n" );
goto exit;
}
/*
* 1.2 Print the key
*/
printf( " ok\n . Key information:\n" );
#if defined(POLARSSL_RSA_C)
if( pk_get_type( &key ) == POLARSSL_PK_RSA )
{
rsa_context *rsa = pk_rsa( key );
mpi_write_file( "N: ", &rsa->N, 16, NULL );
mpi_write_file( "E: ", &rsa->E, 16, NULL );
mpi_write_file( "D: ", &rsa->D, 16, NULL );
mpi_write_file( "P: ", &rsa->P, 16, NULL );
mpi_write_file( "Q: ", &rsa->Q, 16, NULL );
mpi_write_file( "DP: ", &rsa->DP, 16, NULL );
mpi_write_file( "DQ: ", &rsa->DQ, 16, NULL );
mpi_write_file( "QP: ", &rsa->QP, 16, NULL );
}
else
#endif
#if defined(POLARSSL_ECP_C)
if( pk_get_type( &key ) == POLARSSL_PK_ECKEY )
{
ecp_keypair *ecp = pk_ec( key );
printf( "curve: %s\n",
ecp_curve_info_from_grp_id( ecp->grp.id )->name );
mpi_write_file( "X_Q: ", &ecp->Q.X, 16, NULL );
mpi_write_file( "Y_Q: ", &ecp->Q.Y, 16, NULL );
mpi_write_file( "D: ", &ecp->d , 16, NULL );
}
else
#endif
printf(" ! key type not supported\n");
write_private_key( &key, opt.filename );
exit:
if( ret != 0 && ret != 1)
{
#ifdef POLARSSL_ERROR_C
polarssl_strerror( ret, buf, sizeof( buf ) );
printf( " - %s\n", buf );
#else
printf("\n");
#endif
}
pk_free( &key );
ctr_drbg_free( &ctr_drbg );
entropy_free( &entropy );
#if defined(_WIN32)
printf( " + Press Enter to exit this program.\n" );
fflush( stdout ); getchar();
#endif
return( ret );
}
