random: Add a feature to close device file descriptors.
* src/gcrypt.h.in (GCRYCTL_CLOSE_RANDOM_DEVICE): New. * src/global.c (_gcry_vcontrol): Call _gcry_random_close_fds. * random/random.c (_gcry_random_close_fds): New. * random/random-csprng.c (_gcry_rngcsprng_close_fds): New. * random/random-fips.c (_gcry_rngfips_close_fds): New. * random/random-system.c (_gcry_rngsystem_close_fds): New. * random/rndlinux.c (open_device): Add arg retry. (_gcry_rndlinux_gather_random): Add mode to close open fds. * tests/random.c (check_close_random_device): New. (main): Call new test.
- Signed-off-by: Werner Koch <wk@gnupg.org>