blob: 7f1428072d27d612b2345353a7c408a68b9d1df7 [file] [log] [blame]
/* 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.]
*/
/* We need to define this to get macros like S_IFBLK and S_IFCHR */
#if !defined(OPENSSL_SYS_VXWORKS)
#define _XOPEN_SOURCE 500
#endif
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.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>
#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
#ifdef OPENSSL_SYS_VMS
/* 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;
FILE *in;
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_IFBLK) && defined(S_IFCHR) && !defined(OPENSSL_NO_POSIX_IO)
if (sb.st_mode & (S_IFBLK | S_IFCHR)) {
/* 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
#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 = 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
if (OPENSSL_issetugid() == 0)
s=getenv("RANDFILE");
if (s != NULL && *s && strlen(s) + 1 < size)
{
if (BUF_strlcpy(buf,s,size) >= size)
return NULL;
}
else
{
if (OPENSSL_issetugid() == 0)
s=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);
}