/*

 * Copyright 1995-2024 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (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

 */

#if defined (__TANDEM) && defined (_SPT_MODEL_)

/*

 * These definitions have to come first in SPT due to scoping of the

 * declarations in c99 associated with SPT use of stat.

 */

# include <sys/types.h>

# include <sys/stat.h>

#endif

#include "e_os.h"

#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

#include <sys/types.h>

#ifndef OPENSSL_NO_POSIX_IO

# include <sys/stat.h>

# include <fcntl.h>

# if defined(_WIN32) && !defined(_WIN32_WCE)

#  include <windows.h>

#  include <io.h>

#  define stat    _stat

#  define chmod   _chmod

#  define open    _open

#  define fdopen  _fdopen

#  define fstat   _fstat

#  define fileno  _fileno

# endif

#endif

/*

 * 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_ISREG)

#   define S_ISREG(m) ((m) & S_IFREG)

# endif

#define RAND_BUF_SIZE 1024

#define RFILE ".rnd"

#ifdef OPENSSL_SYS_VMS

/*

 * __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 functions return this type (a study of stdio.h proves it).

 *

 * 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

/*

 * Note that these functions are intended for seed files only. Entropy

 * devices and EGD sockets are handled in rand_unix.c  If |bytes| is

 * -1 read the complete file; otherwise read the specified amount.

 */

int RAND_load_file(const char *file, long bytes)

{

    /*

     * The load buffer size exceeds the chunk size by the comfortable amount

     * of 'RAND_DRBG_STRENGTH' bytes (not bits!). This is done on purpose

     * to avoid calling RAND_add() with a small final chunk. Instead, such

     * a small final chunk will be added together with the previous chunk

     * (unless it's the only one).

     */

#define RAND_LOAD_BUF_SIZE (RAND_BUF_SIZE + RAND_DRBG_STRENGTH)

    unsigned char buf[RAND_LOAD_BUF_SIZE];

#ifndef OPENSSL_NO_POSIX_IO

    struct stat sb;

#endif

    int i, n, ret = 0;

    FILE *in;

    if (bytes == 0)

        return 0;

    if ((in = openssl_fopen(file, "rb")) == NULL) {

        ERR_raise_data(ERR_LIB_RAND, RAND_R_CANNOT_OPEN_FILE,

                       "Filename=%s", file);

        return -1;

    }

#ifndef OPENSSL_NO_POSIX_IO

    if (fstat(fileno(in), &sb) < 0) {

        ERR_raise_data(ERR_LIB_RAND, RAND_R_INTERNAL_ERROR,

                       "Filename=%s", file);

        fclose(in);

        return -1;

    }

    if (bytes < 0) {

        if (S_ISREG(sb.st_mode))

            bytes = sb.st_size;

        else

            bytes = RAND_DRBG_STRENGTH;

    }

#endif

    /*

     * On VMS, setbuf() will only take 32-bit pointers, and a compilation

     * with /POINTER_SIZE=64 will give off a MAYLOSEDATA2 warning here.

     * However, we trust that the C RTL will never give us a FILE pointer

     * above the first 4 GB of memory, so we simply turn off the warning

     * temporarily.

     */

#if defined(OPENSSL_SYS_VMS) && defined(__DECC)

# pragma environment save

# pragma message disable maylosedata2

#endif

    /*

     * Don't buffer, because even if |file| is regular file, we have

     * no control over the buffer, so why would we want a copy of its

     * contents lying around?

     */

    setbuf(in, NULL);

#if defined(OPENSSL_SYS_VMS) && defined(__DECC)

# pragma environment restore

#endif

    for ( ; ; ) {

        if (bytes > 0)

            n = (bytes <= RAND_LOAD_BUF_SIZE) ? (int)bytes : RAND_BUF_SIZE;

        else

            n = RAND_LOAD_BUF_SIZE;

        i = fread(buf, 1, n, in);

#ifdef EINTR

        if (ferror(in) && errno == EINTR){

            clearerr(in);

            if (i == 0)

                continue;

        }

#endif

        if (i == 0)

            break;

        RAND_add(buf, i, (double)i);

        ret += i;

        /* If given a bytecount, and we did it, break. */

        if (bytes > 0 && (bytes -= i) <= 0)

            break;

    }

    OPENSSL_cleanse(buf, sizeof(buf));

    fclose(in);

    if (!RAND_status()) {

        ERR_raise_data(ERR_LIB_RAND, RAND_R_RESEED_ERROR, "Filename=%s", file);

        return -1;

    }

    return ret;

}

int RAND_write_file(const char *file)

{

    unsigned char buf[RAND_BUF_SIZE];

    int ret = -1;

    FILE *out = NULL;

#ifndef OPENSSL_NO_POSIX_IO

    struct stat sb;

    if (stat(file, &sb) >= 0 && !S_ISREG(sb.st_mode)) {

        ERR_raise_data(ERR_LIB_RAND, RAND_R_NOT_A_REGULAR_FILE,

                       "Filename=%s", file);

        return -1;

    }

#endif

    /* Collect enough random data. */

    if (RAND_priv_bytes(buf, (int)sizeof(buf)) != 1)

        return  -1;

#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");

            if (out == NULL) {

                close(fd);

                ERR_raise_data(ERR_LIB_RAND, RAND_R_CANNOT_OPEN_FILE,

                               "Filename=%s", file);

                return -1;

            }

        }

    }

#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) {

        ERR_raise_data(ERR_LIB_RAND, RAND_R_CANNOT_OPEN_FILE,

                       "Filename=%s", file);

        return -1;

    }

#if !defined(NO_CHMOD) && !defined(OPENSSL_NO_POSIX_IO)

    /*

     * Yes it's late to do this (see above comment), but better than nothing.

     */

    chmod(file, 0600);

#endif

    ret = fwrite(buf, 1, RAND_BUF_SIZE, out);

    fclose(out);

    OPENSSL_cleanse(buf, RAND_BUF_SIZE);

    return ret;

}

const char *RAND_file_name(char *buf, size_t size)

{

    char *s = NULL;

    size_t len;

    int use_randfile = 1;

#if defined(_WIN32) && defined(CP_UTF8) && !defined(_WIN32_WCE)

    DWORD envlen;

    WCHAR *var;

    /* Look up various environment variables. */

    if ((envlen = GetEnvironmentVariableW(var = L"RANDFILE", NULL, 0)) == 0) {

        use_randfile = 0;

        if ((envlen = GetEnvironmentVariableW(var = L"HOME", NULL, 0)) == 0

                && (envlen = GetEnvironmentVariableW(var = L"USERPROFILE",

                                                  NULL, 0)) == 0)

            envlen = GetEnvironmentVariableW(var = L"SYSTEMROOT", NULL, 0);

    }

    /* If we got a value, allocate space to hold it and then get it. */

    if (envlen != 0) {

        int sz;

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

        if (GetEnvironmentVariableW(var, val, envlen) < envlen

                && (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 ((s = ossl_safe_getenv("RANDFILE")) == NULL || *s == '\0') {

        use_randfile = 0;

        s = ossl_safe_getenv("HOME");

    }

#endif

#ifdef DEFAULT_HOME

    if (!use_randfile && s == NULL)

        s = DEFAULT_HOME;

#endif

    if (s == NULL || *s == '\0')

        return NULL;

    len = strlen(s);

    if (use_randfile) {

        if (len + 1 >= size)

            return NULL;

        strcpy(buf, s);

    } else {

        if (len + 1 + strlen(RFILE) + 1 >= size)

            return NULL;

        strcpy(buf, s);

#ifndef OPENSSL_SYS_VMS

        strcat(buf, "/");

#endif

        strcat(buf, RFILE);

    }

    return buf;

}