diff options
41 files changed, 693 insertions, 4 deletions
diff --git a/ChangeLog b/ChangeLog index 4d31f4f81e..91cc64d59f 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,51 @@ +2016-12-12 Florian Weimer <fweimer@redhat.com> + + [BZ #17252] + Add getentropy, getrandom. + * stdlib/sys/random.h: New file. + (headers): Add it. + * stdlib/Makefile (routines): Add getentropy, getrandom. + (tests): Add tst-getrandom. + * stdlib/Versions (GLIBC_2.25): Add getrandom, getentropy. + * stdlib/getentropy.c: New file. + * stdlib/getrandom.c: Likewise. + * stdlib/tst-getrandom.c: Likewise. + * sysdeps/unix/sysv/linux/getentropy.c: Likewise. + * sysdeps/unix/sysv/linux/getrandom.c: Likewise. + * manual/crypt.texi (Unpredictable Bytes): New section. + * manual/math.texi (Pseudo-Random Numbers): Add cross-reference. + * sysdeps/arm/nacl/libc.abilist: Add getrandom, getentropy. + * sysdeps/unix/sysv/linux/aarch64/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/arm/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/hppa/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/i386/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/microblaze/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/nios2/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist: + Likewise. + * sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist: + Likewise. + * sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist: Likewise. + * sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/sh/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise. + * sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise. + 2016-12-10 Florian Weimer <fweimer@redhat.com> [BZ #20956] diff --git a/NEWS b/NEWS index 4fe8886e83..64ed6593cb 100644 --- a/NEWS +++ b/NEWS @@ -96,6 +96,9 @@ Version 2.25 affect the ABI of other libraries that use this type in their interfaces, if they are compiled or used with those options. +* The getentropy and getrandom functions, and the <sys/random.h> header file + have been added. + * The buffer size for byte-oriented stdio streams is now limited to 8192 bytes by default. Previously, on Linux, the default buffer size on most file systems was 4096 bytes (and thus remains unchanged), except on diff --git a/manual/crypt.texi b/manual/crypt.texi index 9f4474023e..4ab512bb37 100644 --- a/manual/crypt.texi +++ b/manual/crypt.texi @@ -45,6 +45,7 @@ encrypted authentication use normal DES. * getpass:: Prompting the user for a password. * crypt:: A one-way function for passwords. * DES Encryption:: Routines for DES encryption. +* Unpredictable Bytes:: Randomness for cryptography purposes. @end menu @node Legal Problems @@ -428,3 +429,114 @@ each byte. The @code{ecb_crypt}, @code{cbc_crypt}, and @code{des_setparity} functions and their accompanying macros are all defined in the header @file{rpc/des_crypt.h}. + +@node Unpredictable Bytes +@section Generating Unpredictable Bytes + +Some cryptographic applications (such as session key generation) need +unpredictable bytes. + +In general, application code should use a deterministic random bit +generator, which could call the @code{getentropy} function described +below internally to obtain randomness to seed the generator. The +@code{getrandom} function is intended for low-level applications which +need additional control over the blocking behavior. + +@comment sys/random.h +@comment GNU +@deftypefun int getentropy (void *@var{buffer}, size_t @var{length}) +@safety{@mtsafe{}@assafe{}@acsafe{}} + +This function writes @var{length} bytes of random data to the array +starting at @var{buffer}, which must be at most 256 bytes long. The +function returns zero on success. On failure, it returns @code{-1} and +@code{errno} is updated accordingly. + +The @code{getentropy} function is declared in the header file +@file{sys/random.h}. It is derived from OpenBSD. + +The @code{getentropy} function is not a cancellation point. A call to +@code{getentropy} can block if the system has just booted and the kernel +entropy pool has not yet been initialized. In this case, the function +will keep blocking even if a signal arrives, and return only after the +entropy pool has been initialized. + +The @code{getentropy} function can fail with several errors, some of +which are listed below. + +@table @code +@item ENOSYS +The kernel does not implement the required system call. + +@item EFAULT +The combination of @var{buffer} and @var{length} arguments specifies +an invalid memory range. + +@item EIO +More than 256 bytes of randomness have been requested, or the buffer +could not be overwritten with random data for an unspecified reason. + +@end table + +@end deftypefun + +@comment sys/random.h +@comment GNU +@deftypefun ssize_t getrandom (void *@var{buffer}, size_t @var{length}, unsigned int @var{flags}) +@safety{@mtsafe{}@assafe{}@acsafe{}} + +This function writes @var{length} bytes of random data to the array +starting at @var{buffer}. On success, this function returns the number +of bytes which have been written to the buffer (which can be less than +@var{length}). On error, @code{-1} is returned, and @code{errno} is +updated accordingly. + +The @code{getrandom} function is declared in the header file +@file{sys/random.h}. It is a GNU extension. + +The following flags are defined for the @var{flags} argument: + +@table @code +@item GRND_RANDOM +Use the @file{/dev/random} (blocking) pool instead of the +@file{/dev/urandom} (non-blocking) pool to obtain randomness. If the +@code{GRND_RANDOM} flag is specified, the @code{getrandom} function can +block even after the randomness source has been initialized. + +@item GRND_NONBLOCK +Instead of blocking, return to the caller immediately if no data is +available. +@end table + +The @code{getrandom} function is a cancellation point. + +Obtaining randomness from the @file{/dev/urandom} pool (i.e., a call +without the @code{GRND_RANDOM} flag) can block if the system has just +booted and the pool has not yet been initialized. + +The @code{getrandom} function can fail with several errors, some of +which are listed below. In addition, the function may not fill the +buffer completely and return a value less than @var{length}. + +@table @code +@item ENOSYS +The kernel does not implement the @code{getrandom} system call. + +@item EAGAIN +No random data was available and @code{GRND_NONBLOCK} was specified in +@var{flags}. + +@item EFAULT +The combination of @var{buffer} and @var{length} arguments specifies +an invalid memory range. + +@item EINTR +The system call was interrupted. During the system boot process, before +the kernel randomness pool is initialized, this can happen even if +@var{flags} is zero. + +@item EINVAL +The @var{flags} argument contains an invalid combination of flags. +@end table + +@end deftypefun diff --git a/manual/math.texi b/manual/math.texi index 5ad8732eca..9b699f1def 100644 --- a/manual/math.texi +++ b/manual/math.texi @@ -1443,7 +1443,8 @@ is convenient when you are debugging a program, but it is unhelpful if you want the program to behave unpredictably. If you want a different pseudo-random series each time your program runs, you must specify a different seed each time. For ordinary purposes, basing the seed on the -current time works well. +current time works well. For random numbers in cryptography, +@pxref{Unpredictable Bytes}. You can obtain repeatable sequences of numbers on a particular machine type by specifying the same initial seed value for the random number diff --git a/stdlib/Makefile b/stdlib/Makefile index 3cce9d98d4..d6512639e0 100644 --- a/stdlib/Makefile +++ b/stdlib/Makefile @@ -28,7 +28,7 @@ headers := stdlib.h bits/stdlib.h bits/stdlib-ldbl.h bits/stdlib-float.h \ errno.h sys/errno.h bits/errno.h \ ucontext.h sys/ucontext.h \ alloca.h fmtmsg.h \ - bits/stdlib-bsearch.h + bits/stdlib-bsearch.h sys/random.h routines := \ atof atoi atol atoll \ @@ -45,7 +45,7 @@ routines := \ srand48 seed48 lcong48 \ drand48_r erand48_r lrand48_r nrand48_r mrand48_r jrand48_r \ srand48_r seed48_r lcong48_r \ - drand48-iter \ + drand48-iter getrandom getentropy \ strfromf strfromd strfroml \ strtol strtoul strtoll strtoull \ strtol_l strtoul_l strtoll_l strtoull_l \ @@ -79,7 +79,8 @@ tests := tst-strtol tst-strtod testmb testrand testsort testdiv \ tst-setcontext3 tst-tls-atexit-nodelete \ tst-strtol-locale tst-strtod-nan-locale tst-strfmon_l \ tst-quick_exit tst-thread-quick_exit tst-width \ - tst-width-stdint tst-strfrom tst-strfrom-locale + tst-width-stdint tst-strfrom tst-strfrom-locale \ + tst-getrandom tests-static := tst-secure-getenv ifeq ($(have-cxx-thread_local),yes) CFLAGS-tst-quick_exit.o = -std=c++11 diff --git a/stdlib/Versions b/stdlib/Versions index 54416b7ea6..415b9945e2 100644 --- a/stdlib/Versions +++ b/stdlib/Versions @@ -115,6 +115,7 @@ libc { GLIBC_2.25 { # s* strfromd; strfromf; strfroml; + getrandom; getentropy; } GLIBC_PRIVATE { # functions which have an additional interface since they are diff --git a/stdlib/getentropy.c b/stdlib/getentropy.c new file mode 100644 index 0000000000..32a24c7633 --- /dev/null +++ b/stdlib/getentropy.c @@ -0,0 +1,31 @@ +/* Stub for getentropy. + 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> + +/* Write LENGTH bytes of randomness starting at BUFFER. Return 0 on + success and -1 on failure. */ +ssize_t +getentropy (void *buffer, size_t length) +{ + __set_errno (ENOSYS); + return -1; +} + +stub_warning (getentropy) diff --git a/stdlib/getrandom.c b/stdlib/getrandom.c new file mode 100644 index 0000000000..a24727bb70 --- /dev/null +++ b/stdlib/getrandom.c @@ -0,0 +1,31 @@ +/* Stub for getrandom. + 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> + +/* Write LENGTH bytes of randomness starting at BUFFER. Return the + number of bytes written, or -1 on error. */ +ssize_t +getrandom (void *buffer, size_t length, unsigned int flags) +{ + __set_errno (ENOSYS); + return -1; +} + +stub_warning (getrandom) diff --git a/stdlib/sys/random.h b/stdlib/sys/random.h new file mode 100644 index 0000000000..610b4685f1 --- /dev/null +++ b/stdlib/sys/random.h @@ -0,0 +1,42 @@ +/* Interfaces for obtaining random bytes. + 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/>. */ + +#ifndef _SYS_RANDOM_H +#define _SYS_RANDOM_H 1 + +#include <features.h> +#include <sys/types.h> + +/* Flags for use with getrandom. */ +#define GRND_NONBLOCK 0x01 +#define GRND_RANDOM 0x02 + +__BEGIN_DECLS + +/* Write LENGTH bytes of randomness starting at BUFFER. Return the + number of bytes written, or -1 on error. */ +ssize_t getrandom (void *__buffer, size_t __length, + unsigned int __flags) __wur; + +/* Write LENGTH bytes of randomness starting at BUFFER. Return 0 on + success or -1 on error. */ +int getentropy (void *__buffer, size_t __length) __wur; + +__END_DECLS + +#endif /* _SYS_RANDOM_H */ diff --git a/stdlib/tst-getrandom.c b/stdlib/tst-getrandom.c new file mode 100644 index 0000000000..a76cd1868b --- /dev/null +++ b/stdlib/tst-getrandom.c @@ -0,0 +1,245 @@ +/* Tests for the getentropy, getrandom functions. + 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 <errno.h> +#include <stdbool.h> +#include <stdio.h> +#include <string.h> +#include <sys/random.h> + +/* Set to true if any errors are encountered. */ +static bool errors; + +/* Test getrandom with a single buffer length. NB: The passed-in + buffer must have room for four extra bytes after the specified + length, which are used to test that getrandom leaves those bytes + unchanged. */ +static void +test_length (char *buffer, size_t length, unsigned int flags) +{ + memset (buffer, 0, length); + strcpy (buffer + length, "123"); + ssize_t ret = getrandom (buffer, length, flags); + if (ret < 0) + { + /* EAGAIN is an expected error with GRND_RANDOM and + GRND_NONBLOCK. */ + if ((flags & GRND_RANDOM) + && (flags & GRND_NONBLOCK) + && errno == EAGAIN) + return; + printf ("error: getrandom (%zu, 0x%x): %m\n", length, flags); + errors = true; + return; + } + if (ret != length) + { + if (flags & GRND_RANDOM) + { + if (ret == 0 || ret > length) + { + printf ("error: getrandom (%zu, 0x%x) returned %zd\n", + length, flags, ret); + errors = true; + } + } + else + { + printf ("error: getrandom (%zu, 0x%x) returned %zd\n", + length, flags, ret); + errors = true; + } + } + if (length >= 7) + { + /* One spurious test failure in 2**56 is sufficiently + unlikely. */ + int non_null = 0; + for (int i = 0; i < length; ++i) + non_null += buffer[i] != 0; + if (non_null == 0) + { + printf ("error: getrandom (%zu, 0x%x) returned all-zero bytes\n", + 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> diff --git a/sysdeps/arm/nacl/libc.abilist b/sysdeps/arm/nacl/libc.abilist index 807e43d935..0a39f4d13e 100644 --- a/sysdeps/arm/nacl/libc.abilist +++ b/sysdeps/arm/nacl/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist index 77accdf5c1..8d3435f210 100644 --- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist +++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist index 659b7fcf37..2381616b71 100644 --- a/sysdeps/unix/sysv/linux/alpha/libc.abilist +++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/arm/libc.abilist b/sysdeps/unix/sysv/linux/arm/libc.abilist index 8bc979ad7f..e2dbf6fee7 100644 --- a/sysdeps/unix/sysv/linux/arm/libc.abilist +++ b/sysdeps/unix/sysv/linux/arm/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/getentropy.c b/sysdeps/unix/sysv/linux/getentropy.c new file mode 100644 index 0000000000..1778632ff1 --- /dev/null +++ b/sysdeps/unix/sysv/linux/getentropy.c @@ -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 diff --git a/sysdeps/unix/sysv/linux/getrandom.c b/sysdeps/unix/sysv/linux/getrandom.c new file mode 100644 index 0000000000..7df0092688 --- /dev/null +++ b/sysdeps/unix/sysv/linux/getrandom.c @@ -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 diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist index 299b705156..231f039e69 100644 --- a/sysdeps/unix/sysv/linux/hppa/libc.abilist +++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist index f00345f673..5d0159348b 100644 --- a/sysdeps/unix/sysv/linux/i386/libc.abilist +++ b/sysdeps/unix/sysv/linux/i386/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist index e5fcf88b18..00ef4d77ab 100644 --- a/sysdeps/unix/sysv/linux/ia64/libc.abilist +++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist index 8f382f680b..7de0b0e9bd 100644 --- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist +++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist index 320b7fef5f..93e1124592 100644 --- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist +++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/microblaze/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/libc.abilist index 21b14262c6..da70083bdd 100644 --- a/sysdeps/unix/sysv/linux/microblaze/libc.abilist +++ b/sysdeps/unix/sysv/linux/microblaze/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist index 5c4b596c54..570bbf6791 100644 --- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist +++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist index 001fa6c129..5022e5a186 100644 --- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist +++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist index 2d870013f7..ca9f91924f 100644 --- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist +++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist index aa1ee66ab7..2a090db5c6 100644 --- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist +++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist index 2471d68e87..d10bb32513 100644 --- a/sysdeps/unix/sysv/linux/nios2/libc.abilist +++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist index 4ba3146902..a7e688bed9 100644 --- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist index 0557c16130..8c32c33076 100644 --- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist index 821384ebd6..2a13e49a9e 100644 --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist @@ -2178,6 +2178,8 @@ 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 diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist index c40a3f1cba..4f29a6db6e 100644 --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist index 5b39a60638..1e9d4f4d91 100644 --- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist +++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist index a9db32f6c2..6b3d9320e1 100644 --- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist +++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/sh/libc.abilist b/sysdeps/unix/sysv/linux/sh/libc.abilist index 294af0a501..93b79d3758 100644 --- a/sysdeps/unix/sysv/linux/sh/libc.abilist +++ b/sysdeps/unix/sysv/linux/sh/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist index 32747bd22d..a29b0c149b 100644 --- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist +++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist index b0ac4d4472..8ac06e9b01 100644 --- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist +++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist index 4d92d81b85..208e7425ff 100644 --- a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist +++ b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist index a68aef7bb7..3d7836d546 100644 --- a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist +++ b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist index 4d92d81b85..208e7425ff 100644 --- a/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist +++ b/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist index b8623fc59f..32cd1e07b4 100644 --- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist +++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist @@ -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 diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist index a61d874dfe..4ff7acf300 100644 --- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist +++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist @@ -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 |