From aafc1dbe4712c86189bbc1d4d54ad8cb4c69be7e Mon Sep 17 00:00:00 2001 From: Michael Biebl Date: Mon, 5 Oct 2020 22:27:18 +0200 Subject: New upstream version 1.27.90 --- shared/systemd/src/basic/random-util.c | 47 +++++++++++++++++++++++++++++++++- 1 file changed, 46 insertions(+), 1 deletion(-) (limited to 'shared/systemd/src/basic/random-util.c') diff --git a/shared/systemd/src/basic/random-util.c b/shared/systemd/src/basic/random-util.c index 512e7af9..9551e762 100644 --- a/shared/systemd/src/basic/random-util.c +++ b/shared/systemd/src/basic/random-util.c @@ -9,11 +9,13 @@ #include #include #include +#include #include #include #include #include #include +#include #include #if HAVE_SYS_AUXV_H @@ -21,6 +23,7 @@ #endif #include "alloc-util.h" +#include "env-util.h" #include "errno-util.h" #include "fd-util.h" #include "fileio.h" @@ -77,7 +80,7 @@ int rdrand(unsigned long *ret) { * hash functions for its hash tables, with a seed generated randomly. The hash tables * systemd employs watch the fill level closely and reseed if necessary. This allows use of * a low quality RNG initially, as long as it improves should a hash table be under attack: - * the attacker after all needs to to trigger many collisions to exploit it for the purpose + * the attacker after all needs to trigger many collisions to exploit it for the purpose * of DoS, but if doing so improves the seed the attack surface is reduced as the attack * takes place. * @@ -116,6 +119,15 @@ int rdrand(unsigned long *ret) { #endif have_rdrand = !!(ecx & bit_RDRND); + + if (have_rdrand > 0) { + /* Allow disabling use of RDRAND with SYSTEMD_RDRAND=0 + If it is unset getenv_bool_secure will return a negative value. */ + if (getenv_bool_secure("SYSTEMD_RDRAND") == 0) { + have_rdrand = false; + return -EOPNOTSUPP; + } + } } if (have_rdrand == 0) @@ -448,4 +460,37 @@ size_t random_pool_size(void) { /* Use the minimum as default, if we can't retrieve the correct value */ return RANDOM_POOL_SIZE_MIN; } + +int random_write_entropy(int fd, const void *seed, size_t size, bool credit) { + int r; + + assert(fd >= 0); + assert(seed && size > 0); + + if (credit) { + _cleanup_free_ struct rand_pool_info *info = NULL; + + /* The kernel API only accepts "int" as entropy count (which is in bits), let's avoid any + * chance for confusion here. */ + if (size > INT_MAX / 8) + return -EOVERFLOW; + + info = malloc(offsetof(struct rand_pool_info, buf) + size); + if (!info) + return -ENOMEM; + + info->entropy_count = size * 8; + info->buf_size = size; + memcpy(info->buf, seed, size); + + if (ioctl(fd, RNDADDENTROPY, info) < 0) + return -errno; + } else { + r = loop_write(fd, seed, size, false); + if (r < 0) + return r; + } + + return 0; +} #endif /* NM_IGNORED */ -- cgit 1.3.0-6-gf8a5