/*
* Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include "internal/cryptlib.h"
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/crypto.h>
#include <openssl/rand.h>
#include <openssl/buffer.h>
#ifdef OPENSSL_SYS_VMS
# include <unixio.h>
#endif
#include <sys/types.h>
#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
# define fstat _fstat
# define fileno _fileno
#endif
#undef BUFSIZE
#define BUFSIZE 1024
#define RAND_DATA 1024
#ifdef OPENSSL_SYS_VMS
/*
* Misc hacks needed for specific cases.
*
* __FILE_ptr32 is a type provided by DEC C headers (types.h specifically)
* to make sure the FILE* is a 32-bit pointer no matter what. We know that
* stdio function return this type (a study of stdio.h proves it).
* Additionally, we create a similar char pointer type for the sake of
* vms_setbuf below.
*/
# if __INITIAL_POINTER_SIZE == 64
# pragma pointer_size save
# pragma pointer_size 32
typedef char *char_ptr32;
# pragma pointer_size restore
/*
* On VMS, setbuf() will only take 32-bit pointers, and a compilation
* with /POINTER_SIZE=64 will give off a MAYLOSEDATA2 warning here.
* Since we know that the FILE* really is a 32-bit pointer expanded to
* 64 bits, we also know it's safe to convert it back to a 32-bit pointer.
* As for the buffer parameter, we only use NULL here, so that passes as
* well...
*/
# define setbuf(fp,buf) (setbuf)((__FILE_ptr32)(fp), (char_ptr32)(buf))
# endif
/*
* This declaration is a nasty hack to get around vms' extension to fopen for
* passing in sharing options being disabled by /STANDARD=ANSI89
*/
static __FILE_ptr32 (*const vms_fopen)(const char *, const char *, ...) =
(__FILE_ptr32 (*)(const char *, const char *, ...))fopen;
# define VMS_OPEN_ATTRS "shr=get,put,upd,del","ctx=bin,stm","rfm=stm","rat=none","mrs=0"
# define openssl_fopen(fname,mode) vms_fopen((fname), (mode), VMS_OPEN_ATTRS)
#endif
#define RFILE ".rnd"
/*
* 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.
*/
unsigned char buf[BUFSIZE];
#ifndef OPENSSL_NO_POSIX_IO
struct stat sb;
#endif
int i, ret = 0, n;
FILE *in = NULL;
if (file == NULL)
return 0;
if (bytes == 0)
return ret;
in = openssl_fopen(file, "rb");
if (in == NULL)
goto err;
#ifndef OPENSSL_NO_POSIX_IO
/*
* 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));
if (fstat(fileno(in), &sb) < 0)
goto err;
RAND_add(&sb, sizeof(sb), 0.0);
# 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 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? */
setbuf(in, NULL); /* don't do buffered reads */
}
# endif
#endif
for (;;) {
if (bytes > 0)
n = (bytes < BUFSIZE) ? (int)bytes : BUFSIZE;
else
n = BUFSIZE;
i = fread(buf, 1, n, in);
if (i <= 0)
break;
RAND_add(buf, i, (double)i);
ret += i;
if (bytes > 0) {
bytes -= n;
if (bytes <= 0)
break;
}
}
OPENSSL_cleanse(buf, BUFSIZE);
err:
if (in != NULL)
fclose(in);
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;
# if defined(S_ISBLK) && defined(S_ISCHR)
# ifdef _WIN32
/*
* Check for |file| being a driver as "ASCII-safe" on Windows,
* because driver paths are always ASCII.
*/
# endif
i = stat(file, &sb);
if (i != -1) {
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) && !defined(OPENSSL_SYS_WINDOWS)
{
# 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
#ifdef OPENSSL_SYS_VMS
/*
* 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 = openssl_fopen(file, "rb+");
#endif
if (out == NULL)
out = openssl_fopen(file, "wb");
if (out == NULL)
goto err;
#if !defined(NO_CHMOD) && !defined(OPENSSL_NO_POSIX_IO)
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;
int use_randfile = 1;
#ifdef __OpenBSD__
struct stat sb;
#endif
#if defined(_WIN32) && defined(CP_UTF8)
DWORD len;
WCHAR *var, *val;
if ((var = L"RANDFILE",
len = GetEnvironmentVariableW(var, NULL, 0)) == 0
&& (var = L"HOME", use_randfile = 0,
len = GetEnvironmentVariableW(var, NULL, 0)) == 0
&& (var = L"USERPROFILE",
len = GetEnvironmentVariableW(var, NULL, 0)) == 0) {
var = L"SYSTEMROOT",
len = GetEnvironmentVariableW(var, NULL, 0);
}
if (len != 0) {
int sz;
val = _alloca(len * sizeof(WCHAR));
if (GetEnvironmentVariableW(var, val, len) < len
&& (sz = WideCharToMultiByte(CP_UTF8, 0, val, -1, NULL, 0,
NULL, NULL)) != 0) {
s = _alloca(sz);
if (WideCharToMultiByte(CP_UTF8, 0, val, -1, s, sz,
NULL, NULL) == 0)
s = NULL;
}
}
#else
if (OPENSSL_issetugid() != 0) {
use_randfile = 0;
} else {
s = getenv("RANDFILE");
if (s == NULL || *s == '\0') {
use_randfile = 0;
s = getenv("HOME");
}
}
#endif
#ifdef DEFAULT_HOME
if (!use_randfile && s == NULL) {
s = DEFAULT_HOME;
}
#endif
if (s != NULL && *s) {
size_t len = strlen(s);
if (use_randfile && len + 1 < size) {
if (OPENSSL_strlcpy(buf, s, size) >= size)
return NULL;
} else if (len + strlen(RFILE) + 2 < size) {
OPENSSL_strlcpy(buf, s, size);
#ifndef OPENSSL_SYS_VMS
OPENSSL_strlcat(buf, "/", size);
#endif
OPENSSL_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] || stat(buf, &sb) == -1)
if (OPENSSL_strlcpy(buf, "/dev/arandom", size) >= size) {
return NULL;
}
#endif
return buf[0] ? buf : NULL;
}
