unsigned char * mk_session_key(uint32_t * len)
{
// We will generate it completely at random,
// which may not be the best idea (see weak keys
// for GCM mode).
int i;
unsigned char * key;
if (!HSinitted)
{
havege_init(&HS);
HSinitted++;
}
key = malloc(4 * sizeof(int));
if (key == NULL)
return NULL;
for (i = 0; i < 4; i++)
{
((int*) key)[i] = havege_rand(&HS);
}
*len = 4 * sizeof(uint32_t);
return key;
}
int main( int argc, char *argv[] )
{
FILE *f;
time_t t;
int i, j, k;
havege_state hs;
unsigned char buf[1024];
if( argc < 2 )
{
fprintf( stderr, "usage: %s <output filename>\n", argv[0] );
return( 1 );
}
if( ( f = fopen( argv[1], "wb+" ) ) == NULL )
{
printf( "failed to open '%s' for writing.\n", argv[0] );
return( 1 );
}
havege_init( &hs );
t = time( NULL );
for( i = 0, k = 32768; i < k; i++ )
{
for( j = 0; j < sizeof( buf ); j++ )
buf[j] = havege_rand( &hs );
fwrite( buf, sizeof( buf ), 1, f );
printf( "Generating 32Mb of data in file '%s'... %04.1f" \
"%% done\r", argv[1], (100 * (float) (i + 1)) / k );
fflush( stdout );
}
if( t == time( NULL ) )
t--;
fclose( f );
return( 0 );
}
extern uint32_t encrypt(unsigned char * key, uint32_t keylen, unsigned char * in, uint32_t inlen, unsigned char * out)
{
gcm_ctx_256b ctx;
int i;
if (!HSinitted)
{
havege_init(&HS);
HSinitted++;
}
for (i = 0; i < 4; i++)
{
((int*) (out + inlen + 16))[i] = havege_rand(&HS);
}
gcm_init_256b(&ctx,key,keylen * 8);
gcm_encrypt_256b(&ctx, out + inlen + 16,16,in,inlen,NULL,0,out,out + inlen);
gcm_destroy_256b(&ctx);
return 32 + inlen;
}