Fixes CVE-2016-6316: Bug in the mixing functions of Libgcrypt's random number generator. An attacker who obtains 4640 bits from the RNG can trivially predict the next 160 bits of output. Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Peter Korsgaard <peter@korsgaard.com>