openssl1.0/crypto/rand/randfile.c
2019-08-09 10:00:55 +02:00

372 lines
12 KiB
C

/* crypto/rand/randfile.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "cryptlib.h"
#include "e_os.h"
#include <openssl/crypto.h>
#include <openssl/rand.h>
#include <openssl/buffer.h>
#ifdef OPENSSL_SYS_VMS
# include <unixio.h>
#endif
#ifndef NO_SYS_TYPES_H
# include <sys/types.h>
#endif
#ifndef OPENSSL_NO_POSIX_IO
# include <sys/stat.h>
# include <fcntl.h>
/*
* Following should not be needed, and we could have been stricter
* and demand S_IS*. But some systems just don't comply... Formally
* below macros are "anatomically incorrect", because normally they
* would look like ((m) & MASK == TYPE), but since MASK availability
* is as questionable, we settle for this poor-man fallback...
*/
# if !defined(S_ISBLK)
# if defined(_S_IFBLK)
# define S_ISBLK(m) ((m) & _S_IFBLK)
# elif defined(S_IFBLK)
# define S_ISBLK(m) ((m) & S_IFBLK)
# elif defined(_WIN32)
# define S_ISBLK(m) 0 /* no concept of block devices on Windows */
# endif
# endif
# if !defined(S_ISCHR)
# if defined(_S_IFCHR)
# define S_ISCHR(m) ((m) & _S_IFCHR)
# elif defined(S_IFCHR)
# define S_ISCHR(m) ((m) & S_IFCHR)
# endif
# endif
#endif
#ifdef _WIN32
# define stat _stat
# define chmod _chmod
# define open _open
# define fdopen _fdopen
#endif
#undef BUFSIZE
#define BUFSIZE 1024
#define RAND_DATA 1024
#if (defined(OPENSSL_SYS_VMS) && (defined(__alpha) || defined(__ia64)))
/*
* This declaration is a nasty hack to get around vms' extension to fopen for
* passing in sharing options being disabled by our /STANDARD=ANSI89
*/
static FILE *(*const vms_fopen)(const char *, const char *, ...) =
(FILE *(*)(const char *, const char *, ...))fopen;
# define VMS_OPEN_ATTRS "shr=get,put,upd,del","ctx=bin,stm","rfm=stm","rat=none","mrs=0"
#endif
/* #define RFILE ".rnd" - defined in ../../e_os.h */
/*
* Note that these functions are intended for seed files only. Entropy
* devices and EGD sockets are handled in rand_unix.c
*/
int RAND_load_file(const char *file, long bytes)
{
/*-
* If bytes >= 0, read up to 'bytes' bytes.
* if bytes == -1, read complete file.
*/
MS_STATIC unsigned char buf[BUFSIZE];
#ifndef OPENSSL_NO_POSIX_IO
struct stat sb;
#endif
int i, ret = 0, n;
/*
* If setvbuf() is to be called, then the FILE pointer
* to it must be 32 bit.
*/
#if !defined OPENSSL_NO_SETVBUF_IONBF && defined(OPENSSL_SYS_VMS) && defined(__VMS_VER) && (__VMS_VER >= 70000000)
/* For 64-bit-->32 bit API Support*/
#if __INITIAL_POINTER_SIZE == 64
#pragma __required_pointer_size __save
#pragma __required_pointer_size 32
#endif
FILE *in; /* setvbuf() requires 32-bit pointers */
#if __INITIAL_POINTER_SIZE == 64
#pragma __required_pointer_size __restore
#endif
#else
FILE *in;
#endif /* OPENSSL_SYS_VMS */
if (file == NULL)
return (0);
#ifndef OPENSSL_NO_POSIX_IO
# ifdef PURIFY
/*
* struct stat can have padding and unused fields that may not be
* initialized in the call to stat(). We need to clear the entire
* structure before calling RAND_add() to avoid complaints from
* applications such as Valgrind.
*/
memset(&sb, 0, sizeof(sb));
# endif
if (stat(file, &sb) < 0)
return (0);
RAND_add(&sb, sizeof(sb), 0.0);
#endif
if (bytes == 0)
return (ret);
#ifdef OPENSSL_SYS_VMS
in = vms_fopen(file, "rb", VMS_OPEN_ATTRS);
#else
in = fopen(file, "rb");
#endif
if (in == NULL)
goto err;
#if defined(S_ISBLK) && defined(S_ISCHR) && !defined(OPENSSL_NO_POSIX_IO)
if (S_ISBLK(sb.st_mode) || S_ISCHR(sb.st_mode)) {
/*
* this file is a device. we don't want read an infinite number of
* bytes from a random device, nor do we want to use buffered I/O
* because we will waste system entropy.
*/
bytes = (bytes == -1) ? 2048 : bytes; /* ok, is 2048 enough? */
# ifndef OPENSSL_NO_SETVBUF_IONBF
setvbuf(in, NULL, _IONBF, 0); /* don't do buffered reads */
# endif /* ndef OPENSSL_NO_SETVBUF_IONBF */
}
#endif
for (;;) {
if (bytes > 0)
n = (bytes < BUFSIZE) ? (int)bytes : BUFSIZE;
else
n = BUFSIZE;
i = fread(buf, 1, n, in);
if (i <= 0)
break;
#ifdef PURIFY
RAND_add(buf, i, (double)i);
#else
/* even if n != i, use the full array */
RAND_add(buf, n, (double)i);
#endif
ret += i;
if (bytes > 0) {
bytes -= n;
if (bytes <= 0)
break;
}
}
fclose(in);
OPENSSL_cleanse(buf, BUFSIZE);
err:
return (ret);
}
int RAND_write_file(const char *file)
{
unsigned char buf[BUFSIZE];
int i, ret = 0, rand_err = 0;
FILE *out = NULL;
int n;
#ifndef OPENSSL_NO_POSIX_IO
struct stat sb;
i = stat(file, &sb);
if (i != -1) {
# if defined(S_ISBLK) && defined(S_ISCHR)
if (S_ISBLK(sb.st_mode) || S_ISCHR(sb.st_mode)) {
/*
* this file is a device. we don't write back to it. we
* "succeed" on the assumption this is some sort of random
* device. Otherwise attempting to write to and chmod the device
* causes problems.
*/
return (1);
}
# endif
}
#endif
#if defined(O_CREAT) && !defined(OPENSSL_NO_POSIX_IO) && !defined(OPENSSL_SYS_VMS)
{
# ifndef O_BINARY
# define O_BINARY 0
# endif
/*
* chmod(..., 0600) is too late to protect the file, permissions
* should be restrictive from the start
*/
int fd = open(file, O_WRONLY | O_CREAT | O_BINARY, 0600);
if (fd != -1)
out = fdopen(fd, "wb");
}
#endif
#if (defined(OPENSSL_SYS_VMS) && (defined(__alpha) || defined(__ia64)))
/*
* VMS NOTE: Prior versions of this routine created a _new_ version of
* the rand file for each call into this routine, then deleted all
* existing versions named ;-1, and finally renamed the current version
* as ';1'. Under concurrent usage, this resulted in an RMS race
* condition in rename() which could orphan files (see vms message help
* for RMS$_REENT). With the fopen() calls below, openssl/VMS now shares
* the top-level version of the rand file. Note that there may still be
* conditions where the top-level rand file is locked. If so, this code
* will then create a new version of the rand file. Without the delete
* and rename code, this can result in ascending file versions that stop
* at version 32767, and this routine will then return an error. The
* remedy for this is to recode the calling application to avoid
* concurrent use of the rand file, or synchronize usage at the
* application level. Also consider whether or not you NEED a persistent
* rand file in a concurrent use situation.
*/
out = vms_fopen(file, "rb+", VMS_OPEN_ATTRS);
if (out == NULL)
out = vms_fopen(file, "wb", VMS_OPEN_ATTRS);
#else
if (out == NULL)
out = fopen(file, "wb");
#endif
if (out == NULL)
goto err;
#ifndef NO_CHMOD
chmod(file, 0600);
#endif
n = RAND_DATA;
for (;;) {
i = (n > BUFSIZE) ? BUFSIZE : n;
n -= BUFSIZE;
if (RAND_bytes(buf, i) <= 0)
rand_err = 1;
i = fwrite(buf, 1, i, out);
if (i <= 0) {
ret = 0;
break;
}
ret += i;
if (n <= 0)
break;
}
fclose(out);
OPENSSL_cleanse(buf, BUFSIZE);
err:
return (rand_err ? -1 : ret);
}
const char *RAND_file_name(char *buf, size_t size)
{
char *s = NULL;
#ifdef __OpenBSD__
struct stat sb;
#endif
s = ossl_safe_getenv("RANDFILE");
if (s != NULL && *s && strlen(s) + 1 < size) {
if (BUF_strlcpy(buf, s, size) >= size)
return NULL;
} else {
s = ossl_safe_getenv("HOME");
#ifdef DEFAULT_HOME
if (s == NULL) {
s = DEFAULT_HOME;
}
#endif
if (s && *s && strlen(s) + strlen(RFILE) + 2 < size) {
BUF_strlcpy(buf, s, size);
#ifndef OPENSSL_SYS_VMS
BUF_strlcat(buf, "/", size);
#endif
BUF_strlcat(buf, RFILE, size);
} else
buf[0] = '\0'; /* no file name */
}
#ifdef __OpenBSD__
/*
* given that all random loads just fail if the file can't be seen on a
* stat, we stat the file we're returning, if it fails, use /dev/arandom
* instead. this allows the user to use their own source for good random
* data, but defaults to something hopefully decent if that isn't
* available.
*/
if (!buf[0])
if (BUF_strlcpy(buf, "/dev/arandom", size) >= size) {
return (NULL);
}
if (stat(buf, &sb) == -1)
if (BUF_strlcpy(buf, "/dev/arandom", size) >= size) {
return (NULL);
}
#endif
return (buf);
}