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Back out the genentropy.c portion of c648cfe9ff0f

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We don't need to special-case FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
now that we use the glibc arc4random() where available.
This commit is contained in:
Todd C. Miller
2022-12-30 08:02:39 -07:00
parent 91d7592e8a
commit a9a3a8e37b
1 changed files with 54 additions and 63 deletions
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117
lib/util/getentropy.c
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@@ -80,13 +80,6 @@
#include "sudo_digest.h"
#include "sudo_rand.h"
/* Only use getrandom(2) when fuzzing. */
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
# if !defined(SYS_getrandom) || !defined(GRND_NONBLOCK)
# undef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
# endif
#endif
#if !defined(MAP_ANON) && defined(MAP_ANONYMOUS)
# define MAP_ANON MAP_ANONYMOUS
#endif
@@ -113,7 +106,6 @@
int sudo_getentropy(void *buf, size_t len);
static int getentropy_getrandom(void *buf, size_t len);
#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
static int getentropy_sysctl(void *buf, size_t len);
static int getentropy_urandom(void *buf, size_t len, const char *path,
int devfscheck);
@@ -122,7 +114,22 @@ static int gotdata(char *buf, size_t len);
#ifdef HAVE_DL_ITERATE_PHDR
static int getentropy_phdr(struct dl_phdr_info *info, size_t size, void *data);
#endif
#endif /* FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION */
static void *
mmap_anon(void *addr, size_t len, int prot, int flags, off_t offset)
{
#ifdef MAP_ANON
return mmap(addr, len, prot, flags | MAP_ANON, -1, offset);
#else
int fd;
if ((fd = open("/dev/zero", O_RDWR)) == -1)
return MAP_FAILED;
addr = mmap(addr, len, prot, flags, fd, offset);
close(fd);
return addr;
#endif
}
int
sudo_getentropy(void *buf, size_t len)
@@ -138,9 +145,7 @@ sudo_getentropy(void *buf, size_t len)
if (ret != -1)
return (ret);
#if !defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION)
#if defined(HAVE_OPENSSL)
#ifdef HAVE_OPENSSL
if (RAND_bytes(buf, len) == 1)
return (0);
#endif
@@ -188,44 +193,14 @@ sudo_getentropy(void *buf, size_t len)
return (ret);
errno = EIO;
#endif /* FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION */
return (ret);
}
#if defined(SYS_getrandom) && defined(GRND_NONBLOCK)
static int
getentropy_getrandom(void *buf, size_t len)
{
int pre_errno = errno;
int ret;
/*
* This is an open source non-commercial project. Dear PVS-Studio, please check it.
* PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
*/
/*
* Try descriptor-less getrandom(), in non-blocking mode.
*
* The design of Linux getrandom is broken. It has an
* uninitialized phase coupled with blocking behaviour, which
* is unacceptable from within a library at boot time without
* possible recovery. See http://bugs.python.org/issue26839#msg267745
*/
do {
ret = syscall(SYS_getrandom, buf, len, GRND_NONBLOCK);
} while (ret == -1 && errno == EINTR);
if (ret < 0 || (size_t)ret != len)
return (-1);
errno = pre_errno;
return (0);
}
#else
static int
getentropy_getrandom(void *buf, size_t len)
{
errno = ENOTSUP;
return (-1);
}
#endif
#if !defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION)
/*
* Basic validity checking; wish we could do better.
*/
@@ -363,6 +338,39 @@ getentropy_sysctl(void *buf, size_t len)
}
#endif
#if defined(SYS_getrandom) && defined(GRND_NONBLOCK)
static int
getentropy_getrandom(void *buf, size_t len)
{
int pre_errno = errno;
int ret;
/*
* Try descriptor-less getrandom(), in non-blocking mode.
*
* The design of Linux getrandom is broken. It has an
* uninitialized phase coupled with blocking behaviour, which
* is unacceptable from within a library at boot time without
* possible recovery. See http://bugs.python.org/issue26839#msg267745
*/
do {
ret = syscall(SYS_getrandom, buf, len, GRND_NONBLOCK);
} while (ret == -1 && errno == EINTR);
if (ret < 0 || (size_t)ret != len)
return (-1);
errno = pre_errno;
return (0);
}
#else
static int
getentropy_getrandom(void *buf, size_t len)
{
errno = ENOTSUP;
return (-1);
}
#endif
#ifdef HAVE_CLOCK_GETTIME
static const int cl[] = {
CLOCK_REALTIME,
@@ -401,22 +409,6 @@ getentropy_phdr(struct dl_phdr_info *info, size_t size, void *data)
}
#endif
static void *
mmap_anon(void *addr, size_t len, int prot, int flags, off_t offset)
{
#ifdef MAP_ANON
return mmap(addr, len, prot, flags | MAP_ANON, -1, offset);
#else
int fd;
if ((fd = open("/dev/zero", O_RDWR)) == -1)
return MAP_FAILED;
addr = mmap(addr, len, prot, flags, fd, offset);
close(fd);
return addr;
#endif
}
static int
getentropy_fallback(void *buf, size_t len)
{
@@ -646,6 +638,5 @@ done:
freezero(results, digest_len);
return (ret);
}
#endif /* FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION */
#endif /* HAVE_GETENTROPY */