Add getentropy, getrandom, <sys/random.h> [BZ #17252]
This commit is contained in:
Florian Weimer
parent
341657bc9c
commit
92dcaa3e2f
48
ChangeLog
48
ChangeLog
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@ -1,3 +1,51 @@
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2016-12-12 Florian Weimer <fweimer@redhat.com>
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[BZ #17252]
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Add getentropy, getrandom.
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* stdlib/sys/random.h: New file.
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(headers): Add it.
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* stdlib/Makefile (routines): Add getentropy, getrandom.
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(tests): Add tst-getrandom.
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* stdlib/Versions (GLIBC_2.25): Add getrandom, getentropy.
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* stdlib/getentropy.c: New file.
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* stdlib/getrandom.c: Likewise.
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* stdlib/tst-getrandom.c: Likewise.
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* sysdeps/unix/sysv/linux/getentropy.c: Likewise.
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* sysdeps/unix/sysv/linux/getrandom.c: Likewise.
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* manual/crypt.texi (Unpredictable Bytes): New section.
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* manual/math.texi (Pseudo-Random Numbers): Add cross-reference.
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* sysdeps/arm/nacl/libc.abilist: Add getrandom, getentropy.
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* sysdeps/unix/sysv/linux/aarch64/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/arm/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/hppa/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/i386/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/microblaze/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/nios2/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist:
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Likewise.
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* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist:
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Likewise.
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* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist: Likewise.
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* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/sh/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise.
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* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
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2016-12-10 Florian Weimer <fweimer@redhat.com>
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[BZ #20956]
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3
NEWS
3
NEWS
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@ -96,6 +96,9 @@ Version 2.25
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affect the ABI of other libraries that use this type in their interfaces,
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if they are compiled or used with those options.
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* The getentropy and getrandom functions, and the <sys/random.h> header file
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have been added.
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* The buffer size for byte-oriented stdio streams is now limited to 8192
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bytes by default. Previously, on Linux, the default buffer size on most
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file systems was 4096 bytes (and thus remains unchanged), except on
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@ -45,6 +45,7 @@ encrypted authentication use normal DES.
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* getpass:: Prompting the user for a password.
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* crypt:: A one-way function for passwords.
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* DES Encryption:: Routines for DES encryption.
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* Unpredictable Bytes:: Randomness for cryptography purposes.
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@end menu
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@node Legal Problems
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@ -428,3 +429,114 @@ each byte.
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The @code{ecb_crypt}, @code{cbc_crypt}, and @code{des_setparity}
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functions and their accompanying macros are all defined in the header
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@file{rpc/des_crypt.h}.
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@node Unpredictable Bytes
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@section Generating Unpredictable Bytes
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Some cryptographic applications (such as session key generation) need
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unpredictable bytes.
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In general, application code should use a deterministic random bit
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generator, which could call the @code{getentropy} function described
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below internally to obtain randomness to seed the generator. The
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@code{getrandom} function is intended for low-level applications which
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need additional control over the blocking behavior.
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@comment sys/random.h
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@comment GNU
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@deftypefun int getentropy (void *@var{buffer}, size_t @var{length})
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@safety{@mtsafe{}@assafe{}@acsafe{}}
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This function writes @var{length} bytes of random data to the array
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starting at @var{buffer}, which must be at most 256 bytes long. The
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function returns zero on success. On failure, it returns @code{-1} and
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@code{errno} is updated accordingly.
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The @code{getentropy} function is declared in the header file
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@file{sys/random.h}. It is derived from OpenBSD.
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The @code{getentropy} function is not a cancellation point. A call to
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@code{getentropy} can block if the system has just booted and the kernel
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entropy pool has not yet been initialized. In this case, the function
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will keep blocking even if a signal arrives, and return only after the
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entropy pool has been initialized.
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The @code{getentropy} function can fail with several errors, some of
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which are listed below.
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@table @code
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@item ENOSYS
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The kernel does not implement the required system call.
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@item EFAULT
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The combination of @var{buffer} and @var{length} arguments specifies
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an invalid memory range.
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@item EIO
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More than 256 bytes of randomness have been requested, or the buffer
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could not be overwritten with random data for an unspecified reason.
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@end table
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@end deftypefun
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@comment sys/random.h
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@comment GNU
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@deftypefun ssize_t getrandom (void *@var{buffer}, size_t @var{length}, unsigned int @var{flags})
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@safety{@mtsafe{}@assafe{}@acsafe{}}
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This function writes @var{length} bytes of random data to the array
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starting at @var{buffer}. On success, this function returns the number
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of bytes which have been written to the buffer (which can be less than
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@var{length}). On error, @code{-1} is returned, and @code{errno} is
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updated accordingly.
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The @code{getrandom} function is declared in the header file
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@file{sys/random.h}. It is a GNU extension.
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The following flags are defined for the @var{flags} argument:
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@table @code
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@item GRND_RANDOM
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Use the @file{/dev/random} (blocking) pool instead of the
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@file{/dev/urandom} (non-blocking) pool to obtain randomness. If the
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@code{GRND_RANDOM} flag is specified, the @code{getrandom} function can
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block even after the randomness source has been initialized.
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@item GRND_NONBLOCK
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Instead of blocking, return to the caller immediately if no data is
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available.
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@end table
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The @code{getrandom} function is a cancellation point.
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Obtaining randomness from the @file{/dev/urandom} pool (i.e., a call
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without the @code{GRND_RANDOM} flag) can block if the system has just
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booted and the pool has not yet been initialized.
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The @code{getrandom} function can fail with several errors, some of
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which are listed below. In addition, the function may not fill the
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buffer completely and return a value less than @var{length}.
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@table @code
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@item ENOSYS
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The kernel does not implement the @code{getrandom} system call.
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@item EAGAIN
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No random data was available and @code{GRND_NONBLOCK} was specified in
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@var{flags}.
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@item EFAULT
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The combination of @var{buffer} and @var{length} arguments specifies
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an invalid memory range.
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@item EINTR
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The system call was interrupted. During the system boot process, before
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the kernel randomness pool is initialized, this can happen even if
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@var{flags} is zero.
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@item EINVAL
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The @var{flags} argument contains an invalid combination of flags.
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@end table
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@end deftypefun
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@ -1443,7 +1443,8 @@ is convenient when you are debugging a program, but it is unhelpful if
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you want the program to behave unpredictably. If you want a different
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pseudo-random series each time your program runs, you must specify a
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different seed each time. For ordinary purposes, basing the seed on the
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current time works well.
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current time works well. For random numbers in cryptography,
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@pxref{Unpredictable Bytes}.
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You can obtain repeatable sequences of numbers on a particular machine type
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by specifying the same initial seed value for the random number
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@ -28,7 +28,7 @@ headers := stdlib.h bits/stdlib.h bits/stdlib-ldbl.h bits/stdlib-float.h \
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errno.h sys/errno.h bits/errno.h \
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ucontext.h sys/ucontext.h \
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alloca.h fmtmsg.h \
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bits/stdlib-bsearch.h
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bits/stdlib-bsearch.h sys/random.h
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routines := \
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atof atoi atol atoll \
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@ -45,7 +45,7 @@ routines := \
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srand48 seed48 lcong48 \
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drand48_r erand48_r lrand48_r nrand48_r mrand48_r jrand48_r \
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srand48_r seed48_r lcong48_r \
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drand48-iter \
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drand48-iter getrandom getentropy \
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strfromf strfromd strfroml \
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strtol strtoul strtoll strtoull \
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strtol_l strtoul_l strtoll_l strtoull_l \
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@ -79,7 +79,8 @@ tests := tst-strtol tst-strtod testmb testrand testsort testdiv \
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tst-setcontext3 tst-tls-atexit-nodelete \
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tst-strtol-locale tst-strtod-nan-locale tst-strfmon_l \
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tst-quick_exit tst-thread-quick_exit tst-width \
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tst-width-stdint tst-strfrom tst-strfrom-locale
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tst-width-stdint tst-strfrom tst-strfrom-locale \
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tst-getrandom
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tests-static := tst-secure-getenv
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ifeq ($(have-cxx-thread_local),yes)
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CFLAGS-tst-quick_exit.o = -std=c++11
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@ -115,6 +115,7 @@ libc {
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GLIBC_2.25 {
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# s*
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strfromd; strfromf; strfroml;
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getrandom; getentropy;
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}
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GLIBC_PRIVATE {
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# functions which have an additional interface since they are
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@ -0,0 +1,31 @@
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/* Stub for getentropy.
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Copyright (C) 2016 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <sys/random.h>
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#include <errno.h>
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/* Write LENGTH bytes of randomness starting at BUFFER. Return 0 on
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success and -1 on failure. */
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ssize_t
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getentropy (void *buffer, size_t length)
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{
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__set_errno (ENOSYS);
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return -1;
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}
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stub_warning (getentropy)
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@ -0,0 +1,31 @@
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/* Stub for getrandom.
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Copyright (C) 2016 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <sys/random.h>
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#include <errno.h>
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/* Write LENGTH bytes of randomness starting at BUFFER. Return the
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number of bytes written, or -1 on error. */
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ssize_t
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getrandom (void *buffer, size_t length, unsigned int flags)
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{
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__set_errno (ENOSYS);
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return -1;
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}
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stub_warning (getrandom)
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@ -0,0 +1,42 @@
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/* Interfaces for obtaining random bytes.
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Copyright (C) 2016 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#ifndef _SYS_RANDOM_H
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#define _SYS_RANDOM_H 1
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#include <features.h>
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#include <sys/types.h>
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/* Flags for use with getrandom. */
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#define GRND_NONBLOCK 0x01
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#define GRND_RANDOM 0x02
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__BEGIN_DECLS
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/* Write LENGTH bytes of randomness starting at BUFFER. Return the
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number of bytes written, or -1 on error. */
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ssize_t getrandom (void *__buffer, size_t __length,
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unsigned int __flags) __wur;
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/* Write LENGTH bytes of randomness starting at BUFFER. Return 0 on
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success or -1 on error. */
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int getentropy (void *__buffer, size_t __length) __wur;
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__END_DECLS
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#endif /* _SYS_RANDOM_H */
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@ -0,0 +1,245 @@
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/* Tests for the getentropy, getrandom functions.
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Copyright (C) 2016 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
|
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modify it under the terms of the GNU Lesser General Public
|
||||
License as published by the Free Software Foundation; either
|
||||
version 2.1 of the License, or (at your option) any later version.
|
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|
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The GNU C Library is distributed in the hope that it will be useful,
|
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but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
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Lesser General Public License for more details.
|
||||
|
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You should have received a copy of the GNU Lesser General Public
|
||||
License along with the GNU C Library; if not, see
|
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<http://www.gnu.org/licenses/>. */
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#include <errno.h>
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#include <stdbool.h>
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#include <stdio.h>
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#include <string.h>
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#include <sys/random.h>
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/* Set to true if any errors are encountered. */
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static bool errors;
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/* Test getrandom with a single buffer length. NB: The passed-in
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buffer must have room for four extra bytes after the specified
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length, which are used to test that getrandom leaves those bytes
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unchanged. */
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static void
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test_length (char *buffer, size_t length, unsigned int flags)
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{
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memset (buffer, 0, length);
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strcpy (buffer + length, "123");
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ssize_t ret = getrandom (buffer, length, flags);
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if (ret < 0)
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{
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/* EAGAIN is an expected error with GRND_RANDOM and
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GRND_NONBLOCK. */
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if ((flags & GRND_RANDOM)
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&& (flags & GRND_NONBLOCK)
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&& errno == EAGAIN)
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return;
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printf ("error: getrandom (%zu, 0x%x): %m\n", length, flags);
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errors = true;
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return;
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}
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if (ret != length)
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{
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if (flags & GRND_RANDOM)
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{
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if (ret == 0 || ret > length)
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{
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printf ("error: getrandom (%zu, 0x%x) returned %zd\n",
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length, flags, ret);
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errors = true;
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}
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}
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else
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{
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printf ("error: getrandom (%zu, 0x%x) returned %zd\n",
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length, flags, ret);
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errors = true;
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}
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}
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if (length >= 7)
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{
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/* One spurious test failure in 2**56 is sufficiently
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unlikely. */
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int non_null = 0;
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for (int i = 0; i < length; ++i)
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non_null += buffer[i] != 0;
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if (non_null == 0)
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{
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printf ("error: getrandom (%zu, 0x%x) returned all-zero bytes\n",
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length, flags);
|
||||
errors = true;
|
||||
}
|
||||
}
|
||||
if (memcmp (buffer + length, "123", 4) != 0)
|
||||
{
|
||||
printf ("error: getrandom (%zu, 0x%x) wrote spurious bytes\n",
|
||||
length, flags);
|
||||
errors = true;
|
||||
}
|
||||
}
|
||||
|
||||
/* Call getrandom repeatedly to fill the buffer. */
|
||||
static bool
|
||||
getrandom_full (char *buffer, size_t length, unsigned int flags)
|
||||
{
|
||||
char *end = buffer + length;
|
||||
while (buffer < end)
|
||||
{
|
||||
ssize_t ret = getrandom (buffer, end - buffer, flags);
|
||||
if (ret < 0)
|
||||
{
|
||||
printf ("error: getrandom (%zu, 0x%x): %m\n", length, flags);
|
||||
errors = true;
|
||||
return false;
|
||||
}
|
||||
buffer += ret;
|
||||
}
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
static void
|
||||
test_flags (unsigned int flags)
|
||||
{
|
||||
/* Test various lengths, but only for !GRND_RANDOM, to conserve
|
||||
entropy. */
|
||||
{
|
||||
enum { max_length = 300 };
|
||||
char buffer[max_length + 4];
|
||||
if (flags & GRND_RANDOM)
|
||||
test_length (buffer, 0, flags);
|
||||
else
|
||||
{
|
||||
for (int length = 0; length <= 9; ++length)
|
||||
test_length (buffer, length, flags);
|
||||
test_length (buffer, 16, flags);
|
||||
test_length (buffer, max_length, flags);
|
||||
}
|
||||
}
|
||||
|
||||
/* Test that getrandom returns different data. */
|
||||
if (!(flags & GRND_NONBLOCK))
|
||||
{
|
||||
char buffer1[8];
|
||||
memset (buffer1, 0, sizeof (buffer1));
|
||||
|
||||
char buffer2[8];
|
||||
memset (buffer2, 0, sizeof (buffer2));
|
||||
|
||||
if (getrandom_full (buffer1, sizeof (buffer1), flags)
|
||||
&& getrandom_full (buffer2, sizeof (buffer2), flags))
|
||||
{
|
||||
/* The probability that these two 8-byte buffers are equal
|
||||
is very small (assuming that two subsequent calls to
|
||||
getrandom result are independent, uniformly distributed
|
||||
random variables). */
|
||||
if (memcmp (buffer1, buffer2, sizeof (buffer1)) == 0)
|
||||
{
|
||||
printf ("error: getrandom returns constant value\n");
|
||||
errors = true;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
static void
|
||||
test_getentropy (void)
|
||||
{
|
||||
char buf[16];
|
||||
memset (buf, '@', sizeof (buf));
|
||||
if (getentropy (buf, 0) != 0)
|
||||
{
|
||||
printf ("error: getentropy zero length: %m\n");
|
||||
errors = true;
|
||||
return;
|
||||
}
|
||||
for (size_t i = 0; i < sizeof (buf); ++i)
|
||||
if (buf[i] != '@')
|
||||
{
|
||||
printf ("error: getentropy modified zero-length buffer\n");
|
||||
errors = true;
|
||||
return;
|
||||
}
|
||||
|
||||
if (getentropy (buf, sizeof (buf)) != 0)
|
||||
{
|
||||
printf ("error: getentropy buf: %m\n");
|
||||
errors = true;
|
||||
return;
|
||||
}
|
||||
|
||||
char buf2[256];
|
||||
_Static_assert (sizeof (buf) < sizeof (buf2), "buf and buf2 compatible");
|
||||
memset (buf2, '@', sizeof (buf2));
|
||||
if (getentropy (buf2, sizeof (buf)) != 0)
|
||||
{
|
||||
printf ("error: getentropy buf2: %m\n");
|
||||
errors = true;
|
||||
return;
|
||||
}
|
||||
|
||||
/* The probability that these two buffers are equal is very
|
||||
small. */
|
||||
if (memcmp (buf, buf2, sizeof (buf) == 0))
|
||||
{
|
||||
printf ("error: getentropy appears to return constant bytes\n");
|
||||
errors = true;
|
||||
return;
|
||||
}
|
||||
|
||||
for (size_t i = sizeof (buf); i < sizeof (buf2); ++i)
|
||||
if (buf2[i] != '@')
|
||||
{
|
||||
printf ("error: getentropy wrote beyond the end of the buffer\n");
|
||||
errors = true;
|
||||
return;
|
||||
}
|
||||
|
||||
char buf3[257];
|
||||
if (getentropy (buf3, sizeof (buf3)) == 0)
|
||||
{
|
||||
printf ("error: getentropy successful for 257 byte buffer\n");
|
||||
errors = true;
|
||||
return;
|
||||
}
|
||||
if (errno != EIO)
|
||||
{
|
||||
printf ("error: getentropy wrong error for 257 byte buffer: %m\n");
|
||||
errors = true;
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
||||
static int
|
||||
do_test (void)
|
||||
{
|
||||
/* Check if getrandom is not supported by this system. */
|
||||
if (getrandom (NULL, 0, 0) == -1 && errno == ENOSYS)
|
||||
return 77;
|
||||
|
||||
for (int use_random = 0; use_random < 2; ++use_random)
|
||||
for (int use_nonblock = 0; use_nonblock < 2; ++use_nonblock)
|
||||
{
|
||||
unsigned int flags = 0;
|
||||
if (use_random)
|
||||
flags |= GRND_RANDOM;
|
||||
if (use_nonblock)
|
||||
flags |= GRND_NONBLOCK;
|
||||
test_flags (flags);
|
||||
}
|
||||
|
||||
test_getentropy ();
|
||||
|
||||
return errors;
|
||||
}
|
||||
|
||||
#include <support/test-driver.c>
|
||||
|
|
@ -1843,6 +1843,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 gnu_dev_major F
|
||||
GLIBC_2.25 gnu_dev_makedev F
|
||||
GLIBC_2.25 gnu_dev_minor F
|
||||
|
|
|
|||
|
|
@ -2090,6 +2090,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -2001,6 +2001,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -91,6 +91,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -0,0 +1,73 @@
|
|||
/* Implementation of getentropy based on the getrandom system call.
|
||||
Copyright (C) 2016 Free Software Foundation, Inc.
|
||||
This file is part of the GNU C Library.
|
||||
|
||||
The GNU C Library is free software; you can redistribute it and/or
|
||||
modify it under the terms of the GNU Lesser General Public
|
||||
License as published by the Free Software Foundation; either
|
||||
version 2.1 of the License, or (at your option) any later version.
|
||||
|
||||
The GNU C Library is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
Lesser General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU Lesser General Public
|
||||
License along with the GNU C Library; if not, see
|
||||
<http://www.gnu.org/licenses/>. */
|
||||
|
||||
#include <sys/random.h>
|
||||
#include <assert.h>
|
||||
#include <errno.h>
|
||||
#include <unistd.h>
|
||||
|
||||
#ifdef __NR_getrandom
|
||||
/* Write LENGTH bytes of randomness starting at BUFFER. Return 0 on
|
||||
success and -1 on failure. */
|
||||
int
|
||||
getentropy (void *buffer, size_t length)
|
||||
{
|
||||
/* The interface is documented to return EIO for buffer lengths
|
||||
longer than 256 bytes. */
|
||||
if (length > 256)
|
||||
{
|
||||
__set_errno (EIO);
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* Try to fill the buffer completely. Even with the 256 byte limit
|
||||
above, we might still receive an EINTR error (when blocking
|
||||
during boot). */
|
||||
void *end = buffer + length;
|
||||
while (buffer < end)
|
||||
{
|
||||
/* NB: No cancellation point. */
|
||||
ssize_t bytes = INLINE_SYSCALL_CALL (getrandom, buffer, end - buffer, 0);
|
||||
if (bytes < 0)
|
||||
{
|
||||
if (errno == EINTR)
|
||||
/* Try again if interrupted by a signal. */
|
||||
continue;
|
||||
else
|
||||
return -1;
|
||||
}
|
||||
if (bytes == 0)
|
||||
{
|
||||
/* No more bytes available. This should not happen under
|
||||
normal circumstances. */
|
||||
__set_errno (EIO);
|
||||
return -1;
|
||||
}
|
||||
/* Try again in case of a short read. */
|
||||
buffer += bytes;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
#else
|
||||
int
|
||||
getentropy (void *buffer, size_t length)
|
||||
{
|
||||
__set_errno (ENOSYS);
|
||||
return -1;
|
||||
}
|
||||
#endif
|
||||
|
|
@ -0,0 +1,43 @@
|
|||
/* Implementation of the getrandom system call.
|
||||
Copyright (C) 2016 Free Software Foundation, Inc.
|
||||
This file is part of the GNU C Library.
|
||||
|
||||
The GNU C Library is free software; you can redistribute it and/or
|
||||
modify it under the terms of the GNU Lesser General Public
|
||||
License as published by the Free Software Foundation; either
|
||||
version 2.1 of the License, or (at your option) any later version.
|
||||
|
||||
The GNU C Library is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
Lesser General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU Lesser General Public
|
||||
License along with the GNU C Library; if not, see
|
||||
<http://www.gnu.org/licenses/>. */
|
||||
|
||||
#include <sys/random.h>
|
||||
#include <errno.h>
|
||||
#include <unistd.h>
|
||||
#include <sysdep-cancel.h>
|
||||
|
||||
#ifdef __NR_getrandom
|
||||
/* Write LENGTH bytes of randomness starting at BUFFER. Return 0 on
|
||||
success and -1 on failure. */
|
||||
ssize_t
|
||||
getrandom (void *buffer, size_t length, unsigned int flags)
|
||||
{
|
||||
return SYSCALL_CANCEL (getrandom, buffer, length, flags);
|
||||
}
|
||||
#else
|
||||
/* Always provide a definition, even if the kernel headers lack the
|
||||
system call number. */
|
||||
ssize_t
|
||||
getrandom (void *buffer, size_t length, unsigned int flags)
|
||||
{
|
||||
/* Ideally, we would add a cancellation point here, but we currently
|
||||
cannot do so inside libc. */
|
||||
__set_errno (ENOSYS);
|
||||
return -1;
|
||||
}
|
||||
#endif
|
||||
|
|
@ -1855,6 +1855,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -2013,6 +2013,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -1877,6 +1877,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -92,6 +92,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -1969,6 +1969,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -2090,6 +2090,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -1944,6 +1944,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -1942,6 +1942,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -1940,6 +1940,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -1935,6 +1935,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -2131,6 +2131,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -1973,6 +1973,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -1978,6 +1978,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -2178,6 +2178,8 @@ GLIBC_2.23 fts64_set F
|
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GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
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GLIBC_2.25 strfroml F
|
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|
|
|
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|
|
@ -92,6 +92,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -1973,6 +1973,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -1874,6 +1874,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -1859,6 +1859,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -1965,6 +1965,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -1903,6 +1903,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -2097,6 +2097,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -2097,6 +2097,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -2097,6 +2097,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -1854,6 +1854,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
|
|
@ -2097,6 +2097,8 @@ GLIBC_2.23 fts64_set F
|
|||
GLIBC_2.24 GLIBC_2.24 A
|
||||
GLIBC_2.24 quick_exit F
|
||||
GLIBC_2.25 GLIBC_2.25 A
|
||||
GLIBC_2.25 getentropy F
|
||||
GLIBC_2.25 getrandom F
|
||||
GLIBC_2.25 strfromd F
|
||||
GLIBC_2.25 strfromf F
|
||||
GLIBC_2.25 strfroml F
|
||||
|
|
|
|||
Loading…
Reference in New Issue