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

 /*
  * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
  * in the file LICENSE in the source distribution or at
  * https://www.openssl.org/source/license.html
  */

 #include "internal/cryptlib.h"

 #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>
 /*
  * Following should not be needed, and we could have been stricter
  * and demand S_IS*. But some systems just don't comply... Formally
  * below macros are "anatomically incorrect", because normally they
  * would look like ((m) & MASK == TYPE), but since MASK availability
  * is as questionable, we settle for this poor-man fallback...
  */
 # if !defined(S_ISBLK)
 #  if defined(_S_IFBLK)
 #   define S_ISBLK(m) ((m) & _S_IFBLK)
 #  elif defined(S_IFBLK)
 #   define S_ISBLK(m) ((m) & S_IFBLK)
 #  elif defined(_WIN32)
 #   define S_ISBLK(m) 0 /* no concept of block devices on Windows */
 #  endif
 # endif
 # if !defined(S_ISCHR)
 #  if defined(_S_IFCHR)
 #   define S_ISCHR(m) ((m) & _S_IFCHR)
 #  elif defined(S_IFCHR)
 #   define S_ISCHR(m) ((m) & S_IFCHR)
 #  endif
 # endif
 #endif

 #ifdef _WIN32
 # define stat    _stat
 # define chmod   _chmod
 # define open    _open
 # define fdopen  _fdopen
 # define fstat   _fstat
 # define fileno  _fileno
 #endif

 #undef BUFSIZE
 #define BUFSIZE 1024
 #define RAND_DATA 1024

 #ifdef OPENSSL_SYS_VMS
 /*
  * Misc hacks needed for specific cases.
  *
  * __FILE_ptr32 is a type provided by DEC C headers (types.h specifically)
  * to make sure the FILE* is a 32-bit pointer no matter what.  We know that
  * stdio function return this type (a study of stdio.h proves it).
  * Additionally, we create a similar char pointer type for the sake of
  * vms_setbuf below.
  */
 # if __INITIAL_POINTER_SIZE == 64
 #  pragma pointer_size save
 #  pragma pointer_size 32
 typedef char *char_ptr32;
 #  pragma pointer_size restore
 /*
  * On VMS, setbuf() will only take 32-bit pointers, and a compilation
  * with /POINTER_SIZE=64 will give off a MAYLOSEDATA2 warning here.
  * Since we know that the FILE* really is a 32-bit pointer expanded to
  * 64 bits, we also know it's safe to convert it back to a 32-bit pointer.
  * As for the buffer parameter, we only use NULL here, so that passes as
  * well...
  */
 #  define setbuf(fp,buf) (setbuf)((__FILE_ptr32)(fp), (char_ptr32)(buf))
 # endif

 /*
  * This declaration is a nasty hack to get around vms' extension to fopen for
  * passing in sharing options being disabled by /STANDARD=ANSI89
  */
 static __FILE_ptr32 (*const vms_fopen)(const char *, const char *, ...) =
       (__FILE_ptr32 (*)(const char *, const char *, ...))fopen;
 # define VMS_OPEN_ATTRS "shr=get,put,upd,del","ctx=bin,stm","rfm=stm","rat=none","mrs=0"

 # define openssl_fopen(fname,mode) vms_fopen((fname), (mode), VMS_OPEN_ATTRS)
 #endif

 #define RFILE ".rnd"

 /*
  * 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.
      */

     unsigned char buf[BUFSIZE];
 #ifndef OPENSSL_NO_POSIX_IO
     struct stat sb;
 #endif
     int i, ret = 0, n;
     FILE *in = NULL;

     if (file == NULL)
         return 0;

     if (bytes == 0)
         return ret;

     in = openssl_fopen(file, "rb");
     if (in == NULL)
         goto err;

 #ifndef OPENSSL_NO_POSIX_IO
     /*
      * 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));
     if (fstat(fileno(in), &sb) < 0)
         goto err;
     RAND_add(&sb, sizeof(sb), 0.0);

 # 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 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? */
         setbuf(in, NULL); /* don't do buffered reads */
     }
 # endif
 #endif
     for (;;) {
         if (bytes > 0)
             n = (bytes < BUFSIZE) ? (int)bytes : BUFSIZE;
         else
             n = BUFSIZE;
         i = fread(buf, 1, n, in);
         if (i <= 0)
             break;

         RAND_add(buf, i, (double)i);
         ret += i;
         if (bytes > 0) {
             bytes -= n;
             if (bytes <= 0)
                 break;
         }
     }
     OPENSSL_cleanse(buf, BUFSIZE);
  err:
     if (in != NULL)
         fclose(in);
     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;

 # if defined(S_ISBLK) && defined(S_ISCHR)
 # ifdef _WIN32
     /*
      * Check for |file| being a driver as "ASCII-safe" on Windows,
      * because driver paths are always ASCII.
      */
 # endif
     i = stat(file, &sb);
     if (i != -1) {
         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) && !defined(OPENSSL_SYS_WINDOWS)
     {
 # 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 = openssl_fopen(file, "rb+");
 #endif
     if (out == NULL)
         out = openssl_fopen(file, "wb");
     if (out == NULL)
         goto err;

 #if !defined(NO_CHMOD) && !defined(OPENSSL_NO_POSIX_IO)
     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;
     int use_randfile = 1;
 #ifdef __OpenBSD__
     struct stat sb;
 #endif

 #if defined(_WIN32) && defined(CP_UTF8)
     DWORD len;
     WCHAR *var, *val;

     if ((var = L"RANDFILE",
          len = GetEnvironmentVariableW(var, NULL, 0)) == 0
         && (var = L"HOME", use_randfile = 0,
             len = GetEnvironmentVariableW(var, NULL, 0)) == 0
         && (var = L"USERPROFILE",
             len = GetEnvironmentVariableW(var, NULL, 0)) == 0) {
         var = L"SYSTEMROOT",
         len = GetEnvironmentVariableW(var, NULL, 0);
     }

     if (len != 0) {
         int sz;

         val = _alloca(len * sizeof(WCHAR));

         if (GetEnvironmentVariableW(var, val, len) < len
             && (sz = WideCharToMultiByte(CP_UTF8, 0, val, -1, NULL, 0,
                                          NULL, NULL)) != 0) {
             s = _alloca(sz);
             if (WideCharToMultiByte(CP_UTF8, 0, val, -1, s, sz,
                                     NULL, NULL) == 0)
                 s = NULL;
         }
     }
 #else
     if (OPENSSL_issetugid() != 0) {
         use_randfile = 0;
     } else {
         s = getenv("RANDFILE");
         if (s == NULL || *s == '\0') {
             use_randfile = 0;
             s = getenv("HOME");
         }
     }
 #endif
 #ifdef DEFAULT_HOME
     if (!use_randfile && s == NULL) {
         s = DEFAULT_HOME;
     }
 #endif
     if (s != NULL && *s) {
         size_t len = strlen(s);

         if (use_randfile && len + 1 < size) {
             if (OPENSSL_strlcpy(buf, s, size) >= size)
                 return NULL;
         } else if (len + strlen(RFILE) + 2 < size) {
             OPENSSL_strlcpy(buf, s, size);
 #ifndef OPENSSL_SYS_VMS
             OPENSSL_strlcat(buf, "/", size);
 #endif
             OPENSSL_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] || stat(buf, &sb) == -1)
         if (OPENSSL_strlcpy(buf, "/dev/arandom", size) >= size) {
             return NULL;
         }
 #endif
     return buf[0] ? buf : NULL;
 }
	/*
	* Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
	*
	* Licensed under the OpenSSL license (the "License"). You may not use
	* this file except in compliance with the License. You can obtain a copy
	* in the file LICENSE in the source distribution or at
	* https://www.openssl.org/source/license.html
	*/

	#include "internal/cryptlib.h"

	#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>
	/*
	* Following should not be needed, and we could have been stricter
	* and demand S_IS*. But some systems just don't comply... Formally
	* below macros are "anatomically incorrect", because normally they
	* would look like ((m) & MASK == TYPE), but since MASK availability
	* is as questionable, we settle for this poor-man fallback...
	*/
	# if !defined(S_ISBLK)
	# if defined(_S_IFBLK)
	# define S_ISBLK(m) ((m) & _S_IFBLK)
	# elif defined(S_IFBLK)
	# define S_ISBLK(m) ((m) & S_IFBLK)
	# elif defined(_WIN32)
	# define S_ISBLK(m) 0 /* no concept of block devices on Windows */
	# endif
	# endif
	# if !defined(S_ISCHR)
	# if defined(_S_IFCHR)
	# define S_ISCHR(m) ((m) & _S_IFCHR)
	# elif defined(S_IFCHR)
	# define S_ISCHR(m) ((m) & S_IFCHR)
	# endif
	# endif
	#endif

	#ifdef _WIN32
	# define stat _stat
	# define chmod _chmod
	# define open _open
	# define fdopen _fdopen
	# define fstat _fstat
	# define fileno _fileno
	#endif

	#undef BUFSIZE
	#define BUFSIZE 1024
	#define RAND_DATA 1024

	#ifdef OPENSSL_SYS_VMS
	/*
	* Misc hacks needed for specific cases.
	*
	* __FILE_ptr32 is a type provided by DEC C headers (types.h specifically)
	* to make sure the FILE* is a 32-bit pointer no matter what. We know that
	* stdio function return this type (a study of stdio.h proves it).
	* Additionally, we create a similar char pointer type for the sake of
	* vms_setbuf below.
	*/
	# if __INITIAL_POINTER_SIZE == 64
	# pragma pointer_size save
	# pragma pointer_size 32
	typedef char *char_ptr32;
	# pragma pointer_size restore
	/*
	* On VMS, setbuf() will only take 32-bit pointers, and a compilation
	* with /POINTER_SIZE=64 will give off a MAYLOSEDATA2 warning here.
	* Since we know that the FILE* really is a 32-bit pointer expanded to
	* 64 bits, we also know it's safe to convert it back to a 32-bit pointer.
	* As for the buffer parameter, we only use NULL here, so that passes as
	* well...
	*/
	# define setbuf(fp,buf) (setbuf)((__FILE_ptr32)(fp), (char_ptr32)(buf))
	# endif

	/*
	* This declaration is a nasty hack to get around vms' extension to fopen for
	* passing in sharing options being disabled by /STANDARD=ANSI89
	*/
	static __FILE_ptr32 (const vms_fopen)(const char , const char *, ...) =
	(__FILE_ptr32 ()(const char , const char *, ...))fopen;
	# define VMS_OPEN_ATTRS "shr=get,put,upd,del","ctx=bin,stm","rfm=stm","rat=none","mrs=0"

	# define openssl_fopen(fname,mode) vms_fopen((fname), (mode), VMS_OPEN_ATTRS)
	#endif

	#define RFILE ".rnd"

	/*
	* 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.
	*/

	unsigned char buf[BUFSIZE];
	#ifndef OPENSSL_NO_POSIX_IO
	struct stat sb;
	#endif
	int i, ret = 0, n;
	FILE *in = NULL;

	if (file == NULL)
	return 0;

	if (bytes == 0)
	return ret;

	in = openssl_fopen(file, "rb");
	if (in == NULL)
	goto err;

	#ifndef OPENSSL_NO_POSIX_IO
	/*
	* 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));
	if (fstat(fileno(in), &sb) < 0)
	goto err;
	RAND_add(&sb, sizeof(sb), 0.0);

	# 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 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? */
	setbuf(in, NULL); /* don't do buffered reads */
	}
	# endif
	#endif
	for (;;) {
	if (bytes > 0)
	n = (bytes < BUFSIZE) ? (int)bytes : BUFSIZE;
	else
	n = BUFSIZE;
	i = fread(buf, 1, n, in);
	if (i <= 0)
	break;

	RAND_add(buf, i, (double)i);
	ret += i;
	if (bytes > 0) {
	bytes -= n;
	if (bytes <= 0)
	break;
	}
	}
	OPENSSL_cleanse(buf, BUFSIZE);
	err:
	if (in != NULL)
	fclose(in);
	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;

	# if defined(S_ISBLK) && defined(S_ISCHR)
	# ifdef _WIN32
	/*
	* Check for \|file\| being a driver as "ASCII-safe" on Windows,
	* because driver paths are always ASCII.
	*/
	# endif
	i = stat(file, &sb);
	if (i != -1) {
	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) && !defined(OPENSSL_SYS_WINDOWS)
	{
	# 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 = openssl_fopen(file, "rb+");
	#endif
	if (out == NULL)
	out = openssl_fopen(file, "wb");
	if (out == NULL)
	goto err;

	#if !defined(NO_CHMOD) && !defined(OPENSSL_NO_POSIX_IO)
	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;
	int use_randfile = 1;
	#ifdef __OpenBSD__
	struct stat sb;
	#endif

	#if defined(_WIN32) && defined(CP_UTF8)
	DWORD len;
	WCHAR var, val;

	if ((var = L"RANDFILE",
	len = GetEnvironmentVariableW(var, NULL, 0)) == 0
	&& (var = L"HOME", use_randfile = 0,
	len = GetEnvironmentVariableW(var, NULL, 0)) == 0
	&& (var = L"USERPROFILE",
	len = GetEnvironmentVariableW(var, NULL, 0)) == 0) {
	var = L"SYSTEMROOT",
	len = GetEnvironmentVariableW(var, NULL, 0);
	}

	if (len != 0) {
	int sz;

	val = _alloca(len * sizeof(WCHAR));

	if (GetEnvironmentVariableW(var, val, len) < len
	&& (sz = WideCharToMultiByte(CP_UTF8, 0, val, -1, NULL, 0,
	NULL, NULL)) != 0) {
	s = _alloca(sz);
	if (WideCharToMultiByte(CP_UTF8, 0, val, -1, s, sz,
	NULL, NULL) == 0)
	s = NULL;
	}
	}
	#else
	if (OPENSSL_issetugid() != 0) {
	use_randfile = 0;
	} else {
	s = getenv("RANDFILE");
	if (s == NULL \|\| *s == '\0') {
	use_randfile = 0;
	s = getenv("HOME");
	}
	}
	#endif
	#ifdef DEFAULT_HOME
	if (!use_randfile && s == NULL) {
	s = DEFAULT_HOME;
	}
	#endif
	if (s != NULL && *s) {
	size_t len = strlen(s);

	if (use_randfile && len + 1 < size) {
	if (OPENSSL_strlcpy(buf, s, size) >= size)
	return NULL;
	} else if (len + strlen(RFILE) + 2 < size) {
	OPENSSL_strlcpy(buf, s, size);
	#ifndef OPENSSL_SYS_VMS
	OPENSSL_strlcat(buf, "/", size);
	#endif
	OPENSSL_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] \|\| stat(buf, &sb) == -1)
	if (OPENSSL_strlcpy(buf, "/dev/arandom", size) >= size) {
	return NULL;
	}
	#endif
	return buf[0] ? buf : NULL;
	}