wbrawner/openssl
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

rand/randfile.c: permit non-regular files in RAND_load_file.

Browse source 
Apparently applications rely on RAND_load_file's ability to work with
non-regular files, customarily with /dev/urandom, so that the ban was
not exactly appropriate.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5737)
This commit is contained in:
Andy Polyakov 2018-03-23 15:12:20 +01:00
parent f770d75b1c
commit 242fcd695d
2 changed files with 31 additions and 15 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

36
crypto/rand/randfile.c
View file

@ -32,6 +32,8 @@
# define chmod _chmod
# define open _open
# define fdopen _fdopen
# define fstat _fstat
# define fileno _fileno
# endif
#endif
@ -82,27 +84,45 @@ int RAND_load_file(const char *file, long bytes)
if (bytes == 0)
return 0;
#ifndef OPENSSL_NO_POSIX_IO
if (stat(file, &sb) < 0 || !S_ISREG(sb.st_mode)) {
RANDerr(RAND_F_RAND_LOAD_FILE, RAND_R_NOT_A_REGULAR_FILE);
ERR_add_error_data(2, "Filename=", file);
return -1;
}
#endif
if ((in = openssl_fopen(file, "rb")) == NULL) {
RANDerr(RAND_F_RAND_LOAD_FILE, RAND_R_CANNOT_OPEN_FILE);
ERR_add_error_data(2, "Filename=", file);
return -1;
}
#ifndef OPENSSL_NO_POSIX_IO
if (fstat(fileno(in), &sb) < 0) {
RANDerr(RAND_F_RAND_LOAD_FILE, RAND_R_INTERNAL_ERROR);
ERR_add_error_data(2, "Filename=", file);
return -1;
}
if (!S_ISREG(sb.st_mode) && bytes < 0)
bytes = 256;
#endif
/*
* Don't buffer, because even if |file| is regular file, we have
* no control over the buffer, so why would we want a copy of its
* contents lying around?
*/
setbuf(in, NULL);
for ( ; ; ) {
if (bytes > 0)
n = (bytes < RAND_FILE_SIZE) ? (int)bytes : RAND_FILE_SIZE;
else
n = RAND_FILE_SIZE;
i = fread(buf, 1, n, in);
if (i <= 0)
#ifdef EINTR
if (ferror(in) && errno == EINTR){
clearerr(in);
if (i == 0)
continue;
}
#endif
if (i == 0)
break;
RAND_add(buf, i, (double)i);
ret += i;

10
doc/man3/RAND_load_file.pod
View file

@ -24,6 +24,9 @@ Do not load the same file multiple times unless its contents have
been updated by RAND_write_file() between reads.
Also, note that B<filename> should be adequately protected so that an
attacker cannot replace or examine the contents.
If B<filename> is not a regular file, then user is considered to be
responsible for any side effects, e.g. non-anticipated blocking or
capture of controlling terminal.
RAND_write_file() writes a number of random bytes (currently 128) to
file B<filename> which can be used to initialize the PRNG by calling
@ -70,13 +73,6 @@ error.
L<RAND_bytes(3)>, L<RAND_add(3)>
=head1 HISTORY
A comment in the source since at least OpenSSL 1.0.2 said that
RAND_load_file() and RAND_write_file() were only intended for regular files,
and not really device special files such as C</dev/random>. This was
poorly enforced before OpenSSL 1.1.1.
=head1 COPYRIGHT
Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.