181519cf38
11b3a0c2c5db115412c37195#explicit zero 1131456ac632#brk 1158ebc243ea#random 115323b39f7e#undefined 116a91d9dddb#merge 11a042b5a0ba#vla formatting 119ec639de1b#pthread 1149571a0a49#read only 11149cc5ccb8#zero 112e613ccbe7#fork mmap 11e239c7dff8#memprot pthread 110b03d92b7f#xor 11de08419b82#junk 11897d4903e2#guard 11648cd68ca3#ptrhread guard 110bc4dbcbd2#stack rand 10aa9cc05d0710a8cdbb6352#explicit zero 10b28302c668#brk 109f8be7d07c#random 10cb91a7ee3a#undefined 1008279e2fdd#merge 106a18bd565d#vla formatting 102f392c2d08#pthread 108bbce1bc50#read only 10725f61db82#zero 104cd257135f#fork mmap 109220cf622b#memprot pthread 108ef71d1ffd#memprot exit 100eaef1abbd#xor 1064f1cc2148#junk 105c42a527cf#guard 105cc8c34e60#pthread guard 107f61cc8a1c#stack rand 9abdf523d269e4b9b31e6f#explicit zero 9a3a22a63d2#brk 97444dbc3cf#random 9dcd3b72ac9#undefined 9543e1df342#merge 9611e5691f7#vla formatting 98de97ce864#pthread 9a475717042#read only 97f0947cc0e#zero 9e9751d3370#fork mmap 983cd86d0d5#memprot pthread 91ebb165455#memprot exit 9488ba483cf#xor 9f9351d884b#junk 985e5bca0a5#move Signed-off-by: Tad <tad@spotco.us>
59 lines
2.1 KiB
Diff
59 lines
2.1 KiB
Diff
From 7444dbc3cf11285fb94d5d00913016afd7b0dff2 Mon Sep 17 00:00:00 2001
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From: Daniel Micay <danielmicay@gmail.com>
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Date: Mon, 4 Mar 2019 04:26:04 -0500
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Subject: [PATCH] use blocking getrandom and avoid urandom fallback
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---
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libc/bionic/getentropy.cpp | 30 ++----------------------------
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1 file changed, 2 insertions(+), 28 deletions(-)
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diff --git a/libc/bionic/getentropy.cpp b/libc/bionic/getentropy.cpp
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index 2c6e417b87..ad49039af1 100644
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--- a/libc/bionic/getentropy.cpp
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+++ b/libc/bionic/getentropy.cpp
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@@ -31,26 +31,6 @@
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#include <sys/random.h>
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#include <unistd.h>
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-static int getentropy_urandom(void* buffer, size_t buffer_size, int saved_errno) {
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- int fd = TEMP_FAILURE_RETRY(open("/dev/urandom", O_RDONLY | O_NOFOLLOW | O_CLOEXEC, 0));
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- if (fd == -1) return -1;
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-
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- size_t collected = 0;
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- while (collected < buffer_size) {
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- ssize_t count = TEMP_FAILURE_RETRY(read(fd, static_cast<char*>(buffer) + collected,
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- buffer_size - collected));
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- if (count == -1) {
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- close(fd);
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- return -1;
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- }
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- collected += count;
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- }
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-
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- close(fd);
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- errno = saved_errno;
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- return 0;
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-}
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-
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int getentropy(void* buffer, size_t buffer_size) {
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if (buffer_size > 256) {
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errno = EIO;
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@@ -62,15 +42,9 @@ int getentropy(void* buffer, size_t buffer_size) {
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size_t collected = 0;
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while (collected < buffer_size) {
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long count = TEMP_FAILURE_RETRY(getrandom(static_cast<char*>(buffer) + collected,
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- buffer_size - collected, GRND_NONBLOCK));
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+ buffer_size - collected, 0));
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if (count == -1) {
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- // EAGAIN: there isn't enough entropy right now.
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- // ENOSYS/EINVAL: getrandom(2) or GRND_NONBLOCK isn't supported.
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- // EFAULT: `buffer` is invalid.
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- // Try /dev/urandom regardless because it can't hurt,
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- // and we don't need to optimize the EFAULT case.
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- // See http://b/33059407 and http://b/67015565.
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- return getentropy_urandom(buffer, buffer_size, saved_errno);
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+ return -1;
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}
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collected += count;
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}
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