openssl/crypto/rand/randfile.c
x2018 1287dabd0b fix some code with obvious wrong coding style
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/16918)
2021-10-28 13:10:46 +10:00

322 lines
9.5 KiB
C

/*
* Copyright 1995-2021 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 "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");
}
#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;
}