8 #include <botan/internal/dev_random.h>
10 #include <sys/types.h>
11 #include <sys/select.h>
21 int open_nonblocking(
const char* pathname)
32 return ::open(pathname, flags);
43 for(
size_t i = 0; i != fsnames.size(); ++i)
45 fd_type fd = open_nonblocking(fsnames[i].c_str());
46 if(fd >= 0 && fd < FD_SETSIZE)
47 devices.push_back(fd);
56 for(
size_t i = 0; i != devices.size(); ++i)
68 const size_t ENTROPY_BITS_PER_BYTE = 8;
69 const size_t MS_WAIT_TIME = 32;
74 int max_fd = devices[0];
77 for(
size_t i = 0; i != devices.size(); ++i)
79 FD_SET(devices[i], &read_set);
80 max_fd = std::max(devices[i], max_fd);
83 struct ::timeval timeout;
85 timeout.tv_sec = (MS_WAIT_TIME / 1000);
86 timeout.tv_usec = (MS_WAIT_TIME % 1000) * 1000;
88 if(::select(max_fd + 1, &read_set, 0, 0, &timeout) < 0)
91 for(
size_t i = 0; i != devices.size(); ++i)
93 if(FD_ISSET(devices[i], &read_set))
95 const ssize_t got = ::read(devices[i], &io_buffer[0], io_buffer.
size());
97 accum.
add(&io_buffer[0], got, ENTROPY_BITS_PER_BYTE);
Device_EntropySource(const std::vector< std::string > &fsnames)
MemoryRegion< byte > & get_io_buffer(size_t size)
void add(const void *bytes, size_t length, double entropy_bits_per_byte)
void poll(Entropy_Accumulator &accum)
size_t desired_remaining_bits() const