/* 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.]

 */

/*

 © Portions copyright (c) 2006 Nokia Corporation.  All rights reserved.

 */

/* 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>

# include <sys/types.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

#ifndef SYMBIAN

#define BUFSIZE	1024

#define RAND_DATA 1024

#else

#define BUFSIZE	512

#define RAND_DATA 512

#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 */

EXPORT_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);

	if (stat(file,&sb) < 0) return(0);

	RAND_add(&sb,sizeof(sb),0.0);

	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,(double)i);

		ret+=i;

		if (bytes > 0)

			{

			bytes-=n;

			if (bytes <= 0) break;

			}

		}

	fclose(in);

	OPENSSL_cleanse(buf,BUFSIZE);

err:

	return(ret);

	}

EXPORT_C 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);

	}

EXPORT_C 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);

	}