/* 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);

 	}