/* 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 <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

#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

#endif

#undef BUFSIZE

#define BUFSIZE 1024

#define RAND_DATA 1024

#if (defined(OPENSSL_SYS_VMS) && (defined(__alpha) || defined(__ia64)))

/*

 * 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;

/*

 * If setvbuf() is to be called, then the FILE pointer

 * to it must be 32 bit.

*/

#if !defined OPENSSL_NO_SETVBUF_IONBF && defined(OPENSSL_SYS_VMS) && defined(__VMS_VER) && (__VMS_VER >= 70000000)

    /* For 64-bit-->32 bit API Support*/

#if __INITIAL_POINTER_SIZE == 64

#pragma __required_pointer_size __save

#pragma __required_pointer_size 32

#endif

    FILE *in; /* setvbuf() requires 32-bit pointers */

#if __INITIAL_POINTER_SIZE == 64

#pragma __required_pointer_size __restore

#endif

#else

    FILE *in;

#endif /* OPENSSL_SYS_VMS */

    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_ISBLK) && defined(S_ISCHR) && !defined(OPENSSL_NO_POSIX_IO)

    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? */

# 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

#if (defined(OPENSSL_SYS_VMS) && (defined(__alpha) || defined(__ia64)))

    /*

     * 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);

}