/* 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 */#define _XOPEN_SOURCE 500#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#ifdef MAC_OS_pre_X# include <stat.h>#else# include <sys/stat.h>#endif#undef BUFSIZE#define BUFSIZE	1024#define RAND_DATA 1024/* #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];	struct stat sb;	int i,ret=0,n;	FILE *in;	if (file == NULL) return(0);	i=stat(file,&sb);	/* If the state fails, put some crap in anyway */	RAND_add(&sb,sizeof(sb),0);	if (i < 0) return(0);	if (bytes == 0) return(ret);	in=fopen(file,"rb");	if (in == NULL) goto err;#if defined(S_IFBLK) && defined(S_IFCHR)	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? */	  setvbuf(in, NULL, _IONBF, 0); /* don't do buffered reads */	}#endif	for (;;)		{		if (bytes > 0)			n = (bytes < BUFSIZE)?(int)bytes:BUFSIZE;		else			n = BUFSIZE;		i=fread(buf,1,n,in);		if (i <= 0) break;		/* even if n != i, use the full array */		RAND_add(buf,n,i);		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;	struct stat sb;		i=stat(file,&sb);	if (i != -1) { #if defined(S_IFBLK) && defined(S_IFCHR)	  if (sb.st_mode & (S_IFBLK | S_IFCHR)) {	    /* 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	}#if defined(O_CREAT) && !defined(OPENSSL_SYS_WIN32)	{	/* For some reason Win32 can't write to files created this way */		/* chmod(..., 0600) is too late to protect the file,	 * permissions should be restrictive from the start */	int fd = open(file, O_CREAT, 0600);	if (fd != -1)		out = fdopen(fd, "wb");	}#endif	if (out == NULL)		out = fopen(file,"wb");	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;                }#ifdef OPENSSL_SYS_VMS	/* Try to delete older versions of the file, until there aren't	   any */	{	char *tmpf;	tmpf = OPENSSL_malloc(strlen(file) + 4);  /* to add ";-1" and a nul */	if (tmpf)		{		strcpy(tmpf, file);		strcat(tmpf, ";-1");		while(delete(tmpf) == 0)			;		rename(file,";1"); /* Make sure it's version 1, or we				      will reach the limit (32767) at				      some point... */		}	}#endif /* OPENSSL_SYS_VMS */	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 ok = 0;#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);			ok = 1;			}		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 (!ok)		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);	}