1 /* Test the getentropy function. 2 Copyright 2020-2021 Free Software Foundation, Inc. 3 4 This program is free software: you can redistribute it and/or modify 5 it under the terms of the GNU General Public License as published by 6 the Free Software Foundation; either version 3 of the License, or 7 (at your option) any later version. 8 9 This program is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License 15 along with this program. If not, see <https://www.gnu.org/licenses/>. */ 16 17 /* Written by Paul Eggert. */ 18 19 #include <config.h> 20 21 #include <unistd.h> 22 23 #include <string.h> 24 25 #include "signature.h" 26 SIGNATURE_CHECK (getentropy, int, (void *, size_t)); 27 28 #include "macros.h" 29 30 char empty_buf[256]; 31 char buf[256]; 32 33 int 34 main (int argc, char *argv[]) /* */ 35 { 36 /* If this test fails, there's something wrong with the setup anyway. */ 37 ASSERT (getentropy (buf, sizeof buf) == 0); 38 39 /* This test fails with probability 2**-2048. (Run it again if so. :-) */ 40 ASSERT (memcmp (buf, empty_buf, sizeof buf) != 0); 41 42 /* It is very unlikely that two calls to getentropy produce the same 43 results. */ 44 { 45 char buf1[8]; 46 char buf2[8]; 47 48 ASSERT (getentropy (buf1, sizeof (buf1)) == 0); 49 ASSERT (getentropy (buf2, sizeof (buf2)) == 0); 50 ASSERT (memcmp (buf1, buf2, sizeof (buf1)) != 0); 51 } 52 53 return 0; 54 }