crypto/rand/randfile.c - third_party/openssl - Git at Google

 /* 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.]
  */

 #include "e_os.h"

 /* 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 <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>
 # include <fcntl.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);
 }
	/* 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.]
	*/

	#include "e_os.h"

	/* 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 <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>
	# include <fcntl.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);
	}