[PATCH v10 2/9] stdlib: Add arc4random tests
Adhemerval Zanella
adhemerval.zanella@linaro.org
Thu Jul 14 11:28:38 GMT 2022
From: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
The basic tst-arc4random-chacha20.c checks if the output of ChaCha20
implementation matches the reference test vectors from RFC8439.
The tst-arc4random-fork.c check if subprocesses generate distinct
streams of randomness (if fork handling is done correctly).
The tst-arc4random-stats.c is a statistical test to the randomness of
arc4random, arc4random_buf, and arc4random_uniform.
The tst-arc4random-thread.c check if threads generate distinct streams
of randomness (if function are thread-safe).
Checked on x86_64-linux-gnu, aarch64-linux, and powerpc64le-linux-gnu.
Co-authored-by: Florian Weimer <fweimer@redhat.com>
Checked on x86_64-linux-gnu and aarch64-linux-gnu.
---
stdlib/Makefile | 7 +
stdlib/tst-arc4random-chacha20.c | 167 +++++++++++++++
stdlib/tst-arc4random-fork.c | 198 ++++++++++++++++++
stdlib/tst-arc4random-stats.c | 147 +++++++++++++
stdlib/tst-arc4random-thread.c | 341 +++++++++++++++++++++++++++++++
5 files changed, 860 insertions(+)
create mode 100644 stdlib/tst-arc4random-chacha20.c
create mode 100644 stdlib/tst-arc4random-fork.c
create mode 100644 stdlib/tst-arc4random-stats.c
create mode 100644 stdlib/tst-arc4random-thread.c
diff --git a/stdlib/Makefile b/stdlib/Makefile
index 62f8253225..a900962685 100644
--- a/stdlib/Makefile
+++ b/stdlib/Makefile
@@ -183,6 +183,9 @@ tests := \
testmb2 \
testrand \
testsort \
+ tst-arc4random-fork \
+ tst-arc4random-stats \
+ tst-arc4random-thread \
tst-at_quick_exit \
tst-atexit \
tst-atof1 \
@@ -243,6 +246,7 @@ tests := \
# tests
tests-internal := \
+ tst-arc4random-chacha20 \
tst-strtod1i \
tst-strtod3 \
tst-strtod4 \
@@ -252,6 +256,7 @@ tests-internal := \
# tests-internal
tests-static := \
+ tst-arc4random-chacha20 \
tst-secure-getenv \
# tests-static
@@ -271,6 +276,8 @@ LDLIBS-test-cxa_atexit-race = $(shared-thread-library)
LDLIBS-test-cxa_atexit-race2 = $(shared-thread-library)
LDLIBS-test-on_exit-race = $(shared-thread-library)
LDLIBS-tst-canon-bz26341 = $(shared-thread-library)
+LDLIBS-tst-arc4random-fork = $(shared-thread-library)
+LDLIBS-tst-arc4random-thread = $(shared-thread-library)
LDLIBS-test-dlclose-exit-race = $(shared-thread-library)
LDFLAGS-test-dlclose-exit-race = $(LDFLAGS-rdynamic)
diff --git a/stdlib/tst-arc4random-chacha20.c b/stdlib/tst-arc4random-chacha20.c
new file mode 100644
index 0000000000..45ba54920d
--- /dev/null
+++ b/stdlib/tst-arc4random-chacha20.c
@@ -0,0 +1,167 @@
+/* Basic tests for chacha20 cypher used in arc4random.
+ Copyright (C) 2022 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
+ <https://www.gnu.org/licenses/>. */
+
+#include <arc4random.h>
+#include <support/check.h>
+#include <sys/cdefs.h>
+
+/* The test does not define CHACHA20_XOR_FINAL to mimic what arc4random
+ actual does. */
+#include <chacha20.c>
+
+static int
+do_test (void)
+{
+ const uint8_t key[CHACHA20_KEY_SIZE] =
+ {
+ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+ };
+ const uint8_t iv[CHACHA20_IV_SIZE] =
+ {
+ 0x0, 0x0, 0x0, 0x0,
+ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+ };
+ const uint8_t expected1[CHACHA20_BUFSIZE] =
+ {
+ 0x76, 0xb8, 0xe0, 0xad, 0xa0, 0xf1, 0x3d, 0x90, 0x40, 0x5d, 0x6a,
+ 0xe5, 0x53, 0x86, 0xbd, 0x28, 0xbd, 0xd2, 0x19, 0xb8, 0xa0, 0x8d,
+ 0xed, 0x1a, 0xa8, 0x36, 0xef, 0xcc, 0x8b, 0x77, 0x0d, 0xc7, 0xda,
+ 0x41, 0x59, 0x7c, 0x51, 0x57, 0x48, 0x8d, 0x77, 0x24, 0xe0, 0x3f,
+ 0xb8, 0xd8, 0x4a, 0x37, 0x6a, 0x43, 0xb8, 0xf4, 0x15, 0x18, 0xa1,
+ 0x1c, 0xc3, 0x87, 0xb6, 0x69, 0xb2, 0xee, 0x65, 0x86, 0x9f, 0x07,
+ 0xe7, 0xbe, 0x55, 0x51, 0x38, 0x7a, 0x98, 0xba, 0x97, 0x7c, 0x73,
+ 0x2d, 0x08, 0x0d, 0xcb, 0x0f, 0x29, 0xa0, 0x48, 0xe3, 0x65, 0x69,
+ 0x12, 0xc6, 0x53, 0x3e, 0x32, 0xee, 0x7a, 0xed, 0x29, 0xb7, 0x21,
+ 0x76, 0x9c, 0xe6, 0x4e, 0x43, 0xd5, 0x71, 0x33, 0xb0, 0x74, 0xd8,
+ 0x39, 0xd5, 0x31, 0xed, 0x1f, 0x28, 0x51, 0x0a, 0xfb, 0x45, 0xac,
+ 0xe1, 0x0a, 0x1f, 0x4b, 0x79, 0x4d, 0x6f, 0x2d, 0x09, 0xa0, 0xe6,
+ 0x63, 0x26, 0x6c, 0xe1, 0xae, 0x7e, 0xd1, 0x08, 0x19, 0x68, 0xa0,
+ 0x75, 0x8e, 0x71, 0x8e, 0x99, 0x7b, 0xd3, 0x62, 0xc6, 0xb0, 0xc3,
+ 0x46, 0x34, 0xa9, 0xa0, 0xb3, 0x5d, 0x01, 0x27, 0x37, 0x68, 0x1f,
+ 0x7b, 0x5d, 0x0f, 0x28, 0x1e, 0x3a, 0xfd, 0xe4, 0x58, 0xbc, 0x1e,
+ 0x73, 0xd2, 0xd3, 0x13, 0xc9, 0xcf, 0x94, 0xc0, 0x5f, 0xf3, 0x71,
+ 0x62, 0x40, 0xa2, 0x48, 0xf2, 0x13, 0x20, 0xa0, 0x58, 0xd7, 0xb3,
+ 0x56, 0x6b, 0xd5, 0x20, 0xda, 0xaa, 0x3e, 0xd2, 0xbf, 0x0a, 0xc5,
+ 0xb8, 0xb1, 0x20, 0xfb, 0x85, 0x27, 0x73, 0xc3, 0x63, 0x97, 0x34,
+ 0xb4, 0x5c, 0x91, 0xa4, 0x2d, 0xd4, 0xcb, 0x83, 0xf8, 0x84, 0x0d,
+ 0x2e, 0xed, 0xb1, 0x58, 0x13, 0x10, 0x62, 0xac, 0x3f, 0x1f, 0x2c,
+ 0xf8, 0xff, 0x6d, 0xcd, 0x18, 0x56, 0xe8, 0x6a, 0x1e, 0x6c, 0x31,
+ 0x67, 0x16, 0x7e, 0xe5, 0xa6, 0x88, 0x74, 0x2b, 0x47, 0xc5, 0xad,
+ 0xfb, 0x59, 0xd4, 0xdf, 0x76, 0xfd, 0x1d, 0xb1, 0xe5, 0x1e, 0xe0,
+ 0x3b, 0x1c, 0xa9, 0xf8, 0x2a, 0xca, 0x17, 0x3e, 0xdb, 0x8b, 0x72,
+ 0x93, 0x47, 0x4e, 0xbe, 0x98, 0x0f, 0x90, 0x4d, 0x10, 0xc9, 0x16,
+ 0x44, 0x2b, 0x47, 0x83, 0xa0, 0xe9, 0x84, 0x86, 0x0c, 0xb6, 0xc9,
+ 0x57, 0xb3, 0x9c, 0x38, 0xed, 0x8f, 0x51, 0xcf, 0xfa, 0xa6, 0x8a,
+ 0x4d, 0xe0, 0x10, 0x25, 0xa3, 0x9c, 0x50, 0x45, 0x46, 0xb9, 0xdc,
+ 0x14, 0x06, 0xa7, 0xeb, 0x28, 0x15, 0x1e, 0x51, 0x50, 0xd7, 0xb2,
+ 0x04, 0xba, 0xa7, 0x19, 0xd4, 0xf0, 0x91, 0x02, 0x12, 0x17, 0xdb,
+ 0x5c, 0xf1, 0xb5, 0xc8, 0x4c, 0x4f, 0xa7, 0x1a, 0x87, 0x96, 0x10,
+ 0xa1, 0xa6, 0x95, 0xac, 0x52, 0x7c, 0x5b, 0x56, 0x77, 0x4a, 0x6b,
+ 0x8a, 0x21, 0xaa, 0xe8, 0x86, 0x85, 0x86, 0x8e, 0x09, 0x4c, 0xf2,
+ 0x9e, 0xf4, 0x09, 0x0a, 0xf7, 0xa9, 0x0c, 0xc0, 0x7e, 0x88, 0x17,
+ 0xaa, 0x52, 0x87, 0x63, 0x79, 0x7d, 0x3c, 0x33, 0x2b, 0x67, 0xca,
+ 0x4b, 0xc1, 0x10, 0x64, 0x2c, 0x21, 0x51, 0xec, 0x47, 0xee, 0x84,
+ 0xcb, 0x8c, 0x42, 0xd8, 0x5f, 0x10, 0xe2, 0xa8, 0xcb, 0x18, 0xc3,
+ 0xb7, 0x33, 0x5f, 0x26, 0xe8, 0xc3, 0x9a, 0x12, 0xb1, 0xbc, 0xc1,
+ 0x70, 0x71, 0x77, 0xb7, 0x61, 0x38, 0x73, 0x2e, 0xed, 0xaa, 0xb7,
+ 0x4d, 0xa1, 0x41, 0x0f, 0xc0, 0x55, 0xea, 0x06, 0x8c, 0x99, 0xe9,
+ 0x26, 0x0a, 0xcb, 0xe3, 0x37, 0xcf, 0x5d, 0x3e, 0x00, 0xe5, 0xb3,
+ 0x23, 0x0f, 0xfe, 0xdb, 0x0b, 0x99, 0x07, 0x87, 0xd0, 0xc7, 0x0e,
+ 0x0b, 0xfe, 0x41, 0x98, 0xea, 0x67, 0x58, 0xdd, 0x5a, 0x61, 0xfb,
+ 0x5f, 0xec, 0x2d, 0xf9, 0x81, 0xf3, 0x1b, 0xef, 0xe1, 0x53, 0xf8,
+ 0x1d, 0x17, 0x16, 0x17, 0x84, 0xdb
+ };
+
+ const uint8_t expected2[CHACHA20_BUFSIZE] =
+ {
+ 0x1c, 0x88, 0x22, 0xd5, 0x3c, 0xd1, 0xee, 0x7d, 0xb5, 0x32, 0x36,
+ 0x48, 0x28, 0xbd, 0xf4, 0x04, 0xb0, 0x40, 0xa8, 0xdc, 0xc5, 0x22,
+ 0xf3, 0xd3, 0xd9, 0x9a, 0xec, 0x4b, 0x80, 0x57, 0xed, 0xb8, 0x50,
+ 0x09, 0x31, 0xa2, 0xc4, 0x2d, 0x2f, 0x0c, 0x57, 0x08, 0x47, 0x10,
+ 0x0b, 0x57, 0x54, 0xda, 0xfc, 0x5f, 0xbd, 0xb8, 0x94, 0xbb, 0xef,
+ 0x1a, 0x2d, 0xe1, 0xa0, 0x7f, 0x8b, 0xa0, 0xc4, 0xb9, 0x19, 0x30,
+ 0x10, 0x66, 0xed, 0xbc, 0x05, 0x6b, 0x7b, 0x48, 0x1e, 0x7a, 0x0c,
+ 0x46, 0x29, 0x7b, 0xbb, 0x58, 0x9d, 0x9d, 0xa5, 0xb6, 0x75, 0xa6,
+ 0x72, 0x3e, 0x15, 0x2e, 0x5e, 0x63, 0xa4, 0xce, 0x03, 0x4e, 0x9e,
+ 0x83, 0xe5, 0x8a, 0x01, 0x3a, 0xf0, 0xe7, 0x35, 0x2f, 0xb7, 0x90,
+ 0x85, 0x14, 0xe3, 0xb3, 0xd1, 0x04, 0x0d, 0x0b, 0xb9, 0x63, 0xb3,
+ 0x95, 0x4b, 0x63, 0x6b, 0x5f, 0xd4, 0xbf, 0x6d, 0x0a, 0xad, 0xba,
+ 0xf8, 0x15, 0x7d, 0x06, 0x2a, 0xcb, 0x24, 0x18, 0xc1, 0x76, 0xa4,
+ 0x75, 0x51, 0x1b, 0x35, 0xc3, 0xf6, 0x21, 0x8a, 0x56, 0x68, 0xea,
+ 0x5b, 0xc6, 0xf5, 0x4b, 0x87, 0x82, 0xf8, 0xb3, 0x40, 0xf0, 0x0a,
+ 0xc1, 0xbe, 0xba, 0x5e, 0x62, 0xcd, 0x63, 0x2a, 0x7c, 0xe7, 0x80,
+ 0x9c, 0x72, 0x56, 0x08, 0xac, 0xa5, 0xef, 0xbf, 0x7c, 0x41, 0xf2,
+ 0x37, 0x64, 0x3f, 0x06, 0xc0, 0x99, 0x72, 0x07, 0x17, 0x1d, 0xe8,
+ 0x67, 0xf9, 0xd6, 0x97, 0xbf, 0x5e, 0xa6, 0x01, 0x1a, 0xbc, 0xce,
+ 0x6c, 0x8c, 0xdb, 0x21, 0x13, 0x94, 0xd2, 0xc0, 0x2d, 0xd0, 0xfb,
+ 0x60, 0xdb, 0x5a, 0x2c, 0x17, 0xac, 0x3d, 0xc8, 0x58, 0x78, 0xa9,
+ 0x0b, 0xed, 0x38, 0x09, 0xdb, 0xb9, 0x6e, 0xaa, 0x54, 0x26, 0xfc,
+ 0x8e, 0xae, 0x0d, 0x2d, 0x65, 0xc4, 0x2a, 0x47, 0x9f, 0x08, 0x86,
+ 0x48, 0xbe, 0x2d, 0xc8, 0x01, 0xd8, 0x2a, 0x36, 0x6f, 0xdd, 0xc0,
+ 0xef, 0x23, 0x42, 0x63, 0xc0, 0xb6, 0x41, 0x7d, 0x5f, 0x9d, 0xa4,
+ 0x18, 0x17, 0xb8, 0x8d, 0x68, 0xe5, 0xe6, 0x71, 0x95, 0xc5, 0xc1,
+ 0xee, 0x30, 0x95, 0xe8, 0x21, 0xf2, 0x25, 0x24, 0xb2, 0x0b, 0xe4,
+ 0x1c, 0xeb, 0x59, 0x04, 0x12, 0xe4, 0x1d, 0xc6, 0x48, 0x84, 0x3f,
+ 0xa9, 0xbf, 0xec, 0x7a, 0x3d, 0xcf, 0x61, 0xab, 0x05, 0x41, 0x57,
+ 0x33, 0x16, 0xd3, 0xfa, 0x81, 0x51, 0x62, 0x93, 0x03, 0xfe, 0x97,
+ 0x41, 0x56, 0x2e, 0xd0, 0x65, 0xdb, 0x4e, 0xbc, 0x00, 0x50, 0xef,
+ 0x55, 0x83, 0x64, 0xae, 0x81, 0x12, 0x4a, 0x28, 0xf5, 0xc0, 0x13,
+ 0x13, 0x23, 0x2f, 0xbc, 0x49, 0x6d, 0xfd, 0x8a, 0x25, 0x68, 0x65,
+ 0x7b, 0x68, 0x6d, 0x72, 0x14, 0x38, 0x2a, 0x1a, 0x00, 0x90, 0x30,
+ 0x17, 0xdd, 0xa9, 0x69, 0x87, 0x84, 0x42, 0xba, 0x5a, 0xff, 0xf6,
+ 0x61, 0x3f, 0x55, 0x3c, 0xbb, 0x23, 0x3c, 0xe4, 0x6d, 0x9a, 0xee,
+ 0x93, 0xa7, 0x87, 0x6c, 0xf5, 0xe9, 0xe8, 0x29, 0x12, 0xb1, 0x8c,
+ 0xad, 0xf0, 0xb3, 0x43, 0x27, 0xb2, 0xe0, 0x42, 0x7e, 0xcf, 0x66,
+ 0xb7, 0xce, 0xb7, 0xc0, 0x91, 0x8d, 0xc4, 0x7b, 0xdf, 0xf1, 0x2a,
+ 0x06, 0x2a, 0xdf, 0x07, 0x13, 0x30, 0x09, 0xce, 0x7a, 0x5e, 0x5c,
+ 0x91, 0x7e, 0x01, 0x68, 0x30, 0x61, 0x09, 0xb7, 0xcb, 0x49, 0x65,
+ 0x3a, 0x6d, 0x2c, 0xae, 0xf0, 0x05, 0xde, 0x78, 0x3a, 0x9a, 0x9b,
+ 0xfe, 0x05, 0x38, 0x1e, 0xd1, 0x34, 0x8d, 0x94, 0xec, 0x65, 0x88,
+ 0x6f, 0x9c, 0x0b, 0x61, 0x9c, 0x52, 0xc5, 0x53, 0x38, 0x00, 0xb1,
+ 0x6c, 0x83, 0x61, 0x72, 0xb9, 0x51, 0x82, 0xdb, 0xc5, 0xee, 0xc0,
+ 0x42, 0xb8, 0x9e, 0x22, 0xf1, 0x1a, 0x08, 0x5b, 0x73, 0x9a, 0x36,
+ 0x11, 0xcd, 0x8d, 0x83, 0x60, 0x18
+ };
+
+ /* Check with the expected internal arc4random keystream buffer. Some
+ architecture optimizations expects a buffer with a minimum size which
+ is a multiple of then ChaCha20 blocksize, so they might not be prepared
+ to handle smaller buffers. */
+
+ uint8_t output[CHACHA20_BUFSIZE];
+
+ uint32_t state[CHACHA20_STATE_LEN];
+ chacha20_init (state, key, iv);
+
+ /* Check with the initial state. */
+ uint8_t input[CHACHA20_BUFSIZE] = { 0 };
+
+ chacha20_crypt (state, output, input, CHACHA20_BUFSIZE);
+ TEST_COMPARE_BLOB (output, sizeof output, expected1, CHACHA20_BUFSIZE);
+
+ /* And on the next round. */
+ chacha20_crypt (state, output, input, CHACHA20_BUFSIZE);
+ TEST_COMPARE_BLOB (output, sizeof output, expected2, CHACHA20_BUFSIZE);
+
+ return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/stdlib/tst-arc4random-fork.c b/stdlib/tst-arc4random-fork.c
new file mode 100644
index 0000000000..019c0a99de
--- /dev/null
+++ b/stdlib/tst-arc4random-fork.c
@@ -0,0 +1,198 @@
+/* Test that subprocesses generate distinct streams of randomness.
+ Copyright (C) 2022 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
+ <https://www.gnu.org/licenses/>. */
+
+/* Collect random data from subprocesses and check that all the
+ results are unique. */
+
+#include <array_length.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <support/check.h>
+#include <support/support.h>
+#include <support/xthread.h>
+#include <support/xunistd.h>
+#include <unistd.h>
+
+/* Perform multiple runs. The subsequent runs start with an
+ already-initialized random number generator. (The number 1500 was
+ seen to reproduce failures reliable in case of a race condition in
+ the fork detection code.) */
+enum { runs = 1500 };
+
+/* One hundred processes in total. This should be high enough to
+ expose any issues, but low enough not to tax the overall system too
+ much. */
+enum { subprocesses = 49 };
+
+/* The total number of processes. */
+enum { processes = subprocesses + 1 };
+
+/* Number of bytes of randomness to generate per process. Large
+ enough to make false positive duplicates extremely unlikely. */
+enum { random_size = 16 };
+
+/* Generated bytes of randomness. */
+struct result
+{
+ unsigned char bytes[random_size];
+};
+
+/* Shared across all processes. */
+static struct shared_data
+{
+ pthread_barrier_t barrier;
+ struct result results[runs][processes];
+} *shared_data;
+
+static void
+generate_arc4random (unsigned char *bytes)
+{
+ for (int i = 0; i < random_size / sizeof (uint32_t); i++)
+ {
+ uint32_t x = arc4random ();
+ memcpy (&bytes[4 * i], &x, sizeof x);
+ }
+}
+
+static void
+generate_arc4random_buf (unsigned char *bytes)
+{
+ arc4random_buf (bytes, random_size);
+}
+
+static void
+generate_arc4random_uniform (unsigned char *bytes)
+{
+ for (int i = 0; i < random_size; i++)
+ bytes[i] = arc4random_uniform (256);
+}
+
+/* Invoked to collect data from a subprocess. */
+static void
+subprocess (int run, int process_index, void (*func)(unsigned char *))
+{
+ xpthread_barrier_wait (&shared_data->barrier);
+ func (shared_data->results[run][process_index].bytes);
+}
+
+/* Used to sort the results. */
+struct index
+{
+ int run;
+ int process_index;
+};
+
+/* Used to sort an array of struct index values. */
+static int
+index_compare (const void *left1, const void *right1)
+{
+ const struct index *left = left1;
+ const struct index *right = right1;
+
+ return memcmp (shared_data->results[left->run][left->process_index].bytes,
+ shared_data->results[right->run][right->process_index].bytes,
+ random_size);
+}
+
+static int
+do_test_func (void (*func)(unsigned char *bytes))
+{
+ /* Collect random data. */
+ for (int run = 0; run < runs; ++run)
+ {
+ pid_t pids[subprocesses];
+ for (int process_index = 0; process_index < subprocesses;
+ ++process_index)
+ {
+ pids[process_index] = xfork ();
+ if (pids[process_index] == 0)
+ {
+ subprocess (run, process_index, func);
+ _exit (0);
+ }
+ }
+
+ /* Trigger all subprocesses. Also add data from the parent
+ process. */
+ subprocess (run, subprocesses, func);
+
+ for (int process_index = 0; process_index < subprocesses;
+ ++process_index)
+ {
+ int status;
+ xwaitpid (pids[process_index], &status, 0);
+ if (status != 0)
+ FAIL_EXIT1 ("subprocess index %d (PID %d) exit status %d\n",
+ process_index, (int) pids[process_index], status);
+ }
+ }
+
+ /* Check for duplicates. */
+ struct index indexes[runs * processes];
+ for (int run = 0; run < runs; ++run)
+ for (int process_index = 0; process_index < processes; ++process_index)
+ indexes[run * processes + process_index]
+ = (struct index) { .run = run, .process_index = process_index };
+ qsort (indexes, array_length (indexes), sizeof (indexes[0]), index_compare);
+ for (size_t i = 1; i < array_length (indexes); ++i)
+ {
+ if (index_compare (indexes + i - 1, indexes + i) == 0)
+ {
+ support_record_failure ();
+ unsigned char *bytes
+ = shared_data->results[indexes[i].run]
+ [indexes[i].process_index].bytes;
+ char *quoted = support_quote_blob (bytes, random_size);
+ printf ("error: duplicate randomness data: \"%s\"\n"
+ " run %d, subprocess %d\n"
+ " run %d, subprocess %d\n",
+ quoted, indexes[i - 1].run, indexes[i - 1].process_index,
+ indexes[i].run, indexes[i].process_index);
+ free (quoted);
+ }
+ }
+
+ return 0;
+}
+
+static int
+do_test (void)
+{
+ shared_data = support_shared_allocate (sizeof (*shared_data));
+ {
+ pthread_barrierattr_t attr;
+ xpthread_barrierattr_init (&attr);
+ xpthread_barrierattr_setpshared (&attr, PTHREAD_PROCESS_SHARED);
+ xpthread_barrier_init (&shared_data->barrier, &attr, processes);
+ xpthread_barrierattr_destroy (&attr);
+ }
+
+ do_test_func (generate_arc4random);
+ do_test_func (generate_arc4random_buf);
+ do_test_func (generate_arc4random_uniform);
+
+ xpthread_barrier_destroy (&shared_data->barrier);
+ support_shared_free (shared_data);
+ shared_data = NULL;
+
+ return 0;
+}
+
+#define TIMEOUT 40
+#include <support/test-driver.c>
diff --git a/stdlib/tst-arc4random-stats.c b/stdlib/tst-arc4random-stats.c
new file mode 100644
index 0000000000..c29be437ed
--- /dev/null
+++ b/stdlib/tst-arc4random-stats.c
@@ -0,0 +1,147 @@
+/* Statistical tests for arc4random-related functions.
+ Copyright (C) 2022 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 <array_length.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <support/check.h>
+
+enum
+{
+ arc4random_key_size = 32
+};
+
+struct key
+{
+ unsigned char data[arc4random_key_size];
+};
+
+/* With 12,000 keys, the probability that a byte in a predetermined
+ position does not have a predetermined value in all generated keys
+ is about 4e-21. The probability that this happens with any of the
+ 16 * 256 possible byte position/values is 1.6e-17. This results in
+ an acceptably low false-positive rate. */
+enum { key_count = 12000 };
+
+static struct key keys[key_count];
+
+/* Used to perform the distribution check. */
+static int byte_counts[arc4random_key_size][256];
+
+/* Bail out after this many failures. */
+enum { failure_limit = 100 };
+
+static void
+find_stuck_bytes (bool (*func) (unsigned char *key))
+{
+ memset (&keys, 0xcc, sizeof (keys));
+
+ int failures = 0;
+ for (int key = 0; key < key_count; ++key)
+ {
+ while (true)
+ {
+ if (func (keys[key].data))
+ break;
+ ++failures;
+ if (failures >= failure_limit)
+ {
+ printf ("warning: bailing out after %d failures\n", failures);
+ return;
+ }
+ }
+ }
+ printf ("info: key generation finished with %d failures\n", failures);
+
+ memset (&byte_counts, 0, sizeof (byte_counts));
+ for (int key = 0; key < key_count; ++key)
+ for (int pos = 0; pos < arc4random_key_size; ++pos)
+ ++byte_counts[pos][keys[key].data[pos]];
+
+ for (int pos = 0; pos < arc4random_key_size; ++pos)
+ for (int byte = 0; byte < 256; ++byte)
+ if (byte_counts[pos][byte] == 0)
+ {
+ support_record_failure ();
+ printf ("error: byte %d never appeared at position %d\n", byte, pos);
+ }
+}
+
+/* Test adapter for arc4random. */
+static bool
+generate_arc4random (unsigned char *key)
+{
+ uint32_t words[arc4random_key_size / 4];
+ _Static_assert (sizeof (words) == arc4random_key_size, "sizeof (words)");
+
+ for (int i = 0; i < array_length (words); ++i)
+ words[i] = arc4random ();
+ memcpy (key, &words, arc4random_key_size);
+ return true;
+}
+
+/* Test adapter for arc4random_buf. */
+static bool
+generate_arc4random_buf (unsigned char *key)
+{
+ arc4random_buf (key, arc4random_key_size);
+ return true;
+}
+
+/* Test adapter for arc4random_uniform. */
+static bool
+generate_arc4random_uniform (unsigned char *key)
+{
+ for (int i = 0; i < arc4random_key_size; ++i)
+ key[i] = arc4random_uniform (256);
+ return true;
+}
+
+/* Test adapter for arc4random_uniform with argument 257. This means
+ that byte 0 happens more often, but we do not perform such a
+ statistcal check, so the test will still pass */
+static bool
+generate_arc4random_uniform_257 (unsigned char *key)
+{
+ for (int i = 0; i < arc4random_key_size; ++i)
+ key[i] = arc4random_uniform (257);
+ return true;
+}
+
+static int
+do_test (void)
+{
+ puts ("info: arc4random implementation test");
+ find_stuck_bytes (generate_arc4random);
+
+ puts ("info: arc4random_buf implementation test");
+ find_stuck_bytes (generate_arc4random_buf);
+
+ puts ("info: arc4random_uniform implementation test");
+ find_stuck_bytes (generate_arc4random_uniform);
+
+ puts ("info: arc4random_uniform implementation test (257 variant)");
+ find_stuck_bytes (generate_arc4random_uniform_257);
+
+ return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/stdlib/tst-arc4random-thread.c b/stdlib/tst-arc4random-thread.c
new file mode 100644
index 0000000000..797048a7cb
--- /dev/null
+++ b/stdlib/tst-arc4random-thread.c
@@ -0,0 +1,341 @@
+/* Test that threads generate distinct streams of randomness.
+ Copyright (C) 2022 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 <array_length.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <support/check.h>
+#include <support/namespace.h>
+#include <support/support.h>
+#include <support/xthread.h>
+
+/* Number of arc4random_buf calls per thread. */
+enum { count_per_thread = 5000 };
+
+/* Number of threads computing randomness. */
+enum { inner_threads = 5 };
+
+/* Number of threads launching other threads. Chosen as to not to
+ overload the system. */
+enum { outer_threads = 7 };
+
+/* Number of launching rounds performed by the outer threads. */
+enum { outer_rounds = 10 };
+
+/* Maximum number of bytes generated in an arc4random call. */
+enum { max_size = 32 };
+
+/* Sizes generated by threads. Must be long enough to be unique with
+ high probability. */
+static const int sizes[] = { 12, 15, 16, 17, 24, 31, max_size };
+
+/* Data structure to capture randomness results. */
+struct blob
+{
+ unsigned int size;
+ int thread_id;
+ unsigned int index;
+ unsigned char bytes[max_size];
+};
+
+struct subprocess_args
+{
+ struct blob *blob;
+ void (*func)(unsigned char *, size_t);
+};
+
+static void
+generate_arc4random (unsigned char *bytes, size_t size)
+{
+ int i;
+ for (i = 0; i < size / sizeof (uint32_t); i++)
+ {
+ uint32_t x = arc4random ();
+ memcpy (&bytes[4 * i], &x, sizeof x);
+ }
+ int rem = size % sizeof (uint32_t);
+ if (rem > 0)
+ {
+ uint32_t x = arc4random ();
+ memcpy (&bytes[4 * i], &x, rem);
+ }
+}
+
+static void
+generate_arc4random_buf (unsigned char *bytes, size_t size)
+{
+ arc4random_buf (bytes, size);
+}
+
+static void
+generate_arc4random_uniform (unsigned char *bytes, size_t size)
+{
+ for (int i = 0; i < size; i++)
+ bytes[i] = arc4random_uniform (256);
+}
+
+#define DYNARRAY_STRUCT dynarray_blob
+#define DYNARRAY_ELEMENT struct blob
+#define DYNARRAY_PREFIX dynarray_blob_
+#include <malloc/dynarray-skeleton.c>
+
+/* Sort blob elements by length first, then by comparing the data
+ member. */
+static int
+compare_blob (const void *left1, const void *right1)
+{
+ const struct blob *left = left1;
+ const struct blob *right = right1;
+
+ if (left->size != right->size)
+ /* No overflow due to limited range. */
+ return left->size - right->size;
+ return memcmp (left->bytes, right->bytes, left->size);
+}
+
+/* Used to store the global result. */
+static pthread_mutex_t global_result_lock = PTHREAD_MUTEX_INITIALIZER;
+static struct dynarray_blob global_result;
+
+/* Copy data to the global result, with locking. */
+static void
+copy_result_to_global (struct dynarray_blob *result)
+{
+ xpthread_mutex_lock (&global_result_lock);
+ size_t old_size = dynarray_blob_size (&global_result);
+ TEST_VERIFY_EXIT
+ (dynarray_blob_resize (&global_result,
+ old_size + dynarray_blob_size (result)));
+ memcpy (dynarray_blob_begin (&global_result) + old_size,
+ dynarray_blob_begin (result),
+ dynarray_blob_size (result) * sizeof (struct blob));
+ xpthread_mutex_unlock (&global_result_lock);
+}
+
+/* Used to assign unique thread IDs. Accessed atomically. */
+static int next_thread_id;
+
+static void *
+inner_thread (void *closure)
+{
+ void (*func) (unsigned char *, size_t) = closure;
+
+ /* Use local result to avoid global lock contention while generating
+ randomness. */
+ struct dynarray_blob result;
+ dynarray_blob_init (&result);
+
+ int thread_id = __atomic_fetch_add (&next_thread_id, 1, __ATOMIC_RELAXED);
+
+ /* Determine the sizes to be used by this thread. */
+ int size_slot = thread_id % (array_length (sizes) + 1);
+ bool switch_sizes = size_slot == array_length (sizes);
+ if (switch_sizes)
+ size_slot = 0;
+
+ /* Compute the random blobs. */
+ for (int i = 0; i < count_per_thread; ++i)
+ {
+ struct blob *place = dynarray_blob_emplace (&result);
+ TEST_VERIFY_EXIT (place != NULL);
+ place->size = sizes[size_slot];
+ place->thread_id = thread_id;
+ place->index = i;
+ func (place->bytes, place->size);
+
+ if (switch_sizes)
+ size_slot = (size_slot + 1) % array_length (sizes);
+ }
+
+ /* Store the blobs in the global result structure. */
+ copy_result_to_global (&result);
+
+ dynarray_blob_free (&result);
+
+ return NULL;
+}
+
+/* Launch the inner threads and wait for their termination. */
+static void *
+outer_thread (void *closure)
+{
+ void (*func) (unsigned char *, size_t) = closure;
+
+ for (int round = 0; round < outer_rounds; ++round)
+ {
+ pthread_t threads[inner_threads];
+
+ for (int i = 0; i < inner_threads; ++i)
+ threads[i] = xpthread_create (NULL, inner_thread, func);
+
+ for (int i = 0; i < inner_threads; ++i)
+ xpthread_join (threads[i]);
+ }
+
+ return NULL;
+}
+
+static bool termination_requested;
+
+/* Call arc4random_buf to fill one blob with 16 bytes. */
+static void *
+get_one_blob_thread (void *closure)
+{
+ struct subprocess_args *arg = closure;
+ struct blob *result = arg->blob;
+
+ result->size = 16;
+ arg->func (result->bytes, result->size);
+ return NULL;
+}
+
+/* Invoked from fork_thread to actually obtain randomness data. */
+static void
+fork_thread_subprocess (void *closure)
+{
+ struct subprocess_args *arg = closure;
+ struct blob *shared_result = arg->blob;
+
+ struct subprocess_args args[3] =
+ {
+ { shared_result + 0, arg->func },
+ { shared_result + 1, arg->func },
+ { shared_result + 2, arg->func }
+ };
+
+ pthread_t thr1 = xpthread_create (NULL, get_one_blob_thread, &args[1]);
+ pthread_t thr2 = xpthread_create (NULL, get_one_blob_thread, &args[2]);
+ get_one_blob_thread (&args[0]);
+ xpthread_join (thr1);
+ xpthread_join (thr2);
+}
+
+/* Continuously fork subprocesses to obtain a little bit of
+ randomness. */
+static void *
+fork_thread (void *closure)
+{
+ void (*func)(unsigned char *, size_t) = closure;
+
+ struct dynarray_blob result;
+ dynarray_blob_init (&result);
+
+ /* Three blobs from each subprocess. */
+ struct blob *shared_result
+ = support_shared_allocate (3 * sizeof (*shared_result));
+
+ while (!__atomic_load_n (&termination_requested, __ATOMIC_RELAXED))
+ {
+ /* Obtain the results from a subprocess. */
+ struct subprocess_args arg = { shared_result, func };
+ support_isolate_in_subprocess (fork_thread_subprocess, &arg);
+
+ for (int i = 0; i < 3; ++i)
+ {
+ struct blob *place = dynarray_blob_emplace (&result);
+ TEST_VERIFY_EXIT (place != NULL);
+ place->size = shared_result[i].size;
+ place->thread_id = -1;
+ place->index = i;
+ memcpy (place->bytes, shared_result[i].bytes, place->size);
+ }
+ }
+
+ support_shared_free (shared_result);
+
+ copy_result_to_global (&result);
+ dynarray_blob_free (&result);
+
+ return NULL;
+}
+
+/* Launch the outer threads and wait for their termination. */
+static void
+run_outer_threads (void (*func)(unsigned char *, size_t))
+{
+ /* Special thread that continuously calls fork. */
+ pthread_t fork_thread_id = xpthread_create (NULL, fork_thread, func);
+
+ pthread_t threads[outer_threads];
+ for (int i = 0; i < outer_threads; ++i)
+ threads[i] = xpthread_create (NULL, outer_thread, func);
+
+ for (int i = 0; i < outer_threads; ++i)
+ xpthread_join (threads[i]);
+
+ __atomic_store_n (&termination_requested, true, __ATOMIC_RELAXED);
+ xpthread_join (fork_thread_id);
+}
+
+static int
+do_test_func (const char *fname, void (*func)(unsigned char *, size_t))
+{
+ dynarray_blob_init (&global_result);
+ int expected_blobs
+ = count_per_thread * inner_threads * outer_threads * outer_rounds;
+ printf ("info: %s: minimum of %d blob results expected\n",
+ fname, expected_blobs);
+
+ run_outer_threads (func);
+
+ /* The forking thread delivers a non-deterministic number of
+ results, which is why expected_blobs is only a minimun number of
+ results. */
+ printf ("info: %s: %zu blob results observed\n", fname,
+ dynarray_blob_size (&global_result));
+ TEST_VERIFY (dynarray_blob_size (&global_result) >= expected_blobs);
+
+ /* Verify that there are no duplicates. */
+ qsort (dynarray_blob_begin (&global_result),
+ dynarray_blob_size (&global_result),
+ sizeof (struct blob), compare_blob);
+ struct blob *end = dynarray_blob_end (&global_result);
+ for (struct blob *p = dynarray_blob_begin (&global_result) + 1;
+ p < end; ++p)
+ {
+ if (compare_blob (p - 1, p) == 0)
+ {
+ support_record_failure ();
+ char *quoted = support_quote_blob (p->bytes, p->size);
+ printf ("error: %s: duplicate blob: \"%s\" (%d bytes)\n",
+ fname, quoted, (int) p->size);
+ printf (" first source: thread %d, index %u\n",
+ p[-1].thread_id, p[-1].index);
+ printf (" second source: thread %d, index %u\n",
+ p[0].thread_id, p[0].index);
+ free (quoted);
+ }
+ }
+
+ dynarray_blob_free (&global_result);
+
+ return 0;
+}
+
+static int
+do_test (void)
+{
+ do_test_func ("arc4random", generate_arc4random);
+ do_test_func ("arc4random_buf", generate_arc4random_buf);
+ do_test_func ("arc4random_uniform", generate_arc4random_uniform);
+
+ return 0;
+}
+
+#include <support/test-driver.c>
--
2.34.1
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