source: trunk/sys/libcrypto/others/randfile.c @ 1

Last change on this file since 1 was 1, checked in by alain, 5 years ago

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1/* crypto/rand/randfile.c */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to.  The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 *    notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 *    notice, this list of conditions and the following disclaimer in the
30 *    documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 *    must display the following acknowledgement:
33 *    "This product includes cryptographic software written by
34 *     Eric Young (eay@cryptsoft.com)"
35 *    The word 'cryptographic' can be left out if the rouines from the library
36 *    being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 *    the apps directory (application code) you must include an acknowledgement:
39 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed.  i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58
59/* We need to define this to get macros like S_IFBLK and S_IFCHR */
60#define _XOPEN_SOURCE 500
61
62#include <errno.h>
63#include <stdio.h>
64#include <stdlib.h>
65#include <string.h>
66
67#include "e_os.h"
68#include <openssl/crypto.h>
69#include <openssl/rand.h>
70#include <openssl/buffer.h>
71
72#ifdef OPENSSL_SYS_VMS
73#include <unixio.h>
74#endif
75#ifndef NO_SYS_TYPES_H
76# include <sys/types.h>
77#endif
78#ifdef MAC_OS_pre_X
79# include <stat.h>
80#else
81# include <sys/stat.h>
82#endif
83
84#ifdef _WIN32
85#define stat    _stat
86#define chmod   _chmod
87#define open    _open
88#define fdopen  _fdopen
89#endif
90
91#undef BUFSIZE
92#define BUFSIZE 1024
93#define RAND_DATA 1024
94
95#ifdef OPENSSL_SYS_VMS
96/* This declaration is a nasty hack to get around vms' extension to fopen
97 * for passing in sharing options being disabled by our /STANDARD=ANSI89 */
98static FILE *(*const vms_fopen)(const char *, const char *, ...) =
99    (FILE *(*)(const char *, const char *, ...))fopen;
100#define VMS_OPEN_ATTRS "shr=get,put,upd,del","ctx=bin,stm","rfm=stm","rat=none","mrs=0"
101#endif
102
103/* #define RFILE ".rnd" - defined in ../../e_os.h */
104
105/* Note that these functions are intended for seed files only.
106 * Entropy devices and EGD sockets are handled in rand_unix.c */
107
108int RAND_load_file(const char *file, long bytes)
109        {
110        /* If bytes >= 0, read up to 'bytes' bytes.
111         * if bytes == -1, read complete file. */
112
113        MS_STATIC unsigned char buf[BUFSIZE];
114        struct stat sb;
115        int i,ret=0,n;
116        FILE *in;
117
118        if (file == NULL) return(0);
119
120        if (stat(file,&sb) < 0) return(0);
121        RAND_add(&sb,sizeof(sb),0.0);
122        if (bytes == 0) return(ret);
123
124#ifdef OPENSSL_SYS_VMS
125        in=vms_fopen(file,"rb",VMS_OPEN_ATTRS);
126#else
127        in=fopen(file,"rb");
128#endif
129        if (in == NULL) goto err;
130#if defined(S_IFBLK) && defined(S_IFCHR)
131        if (sb.st_mode & (S_IFBLK | S_IFCHR)) {
132          /* this file is a device. we don't want read an infinite number
133           * of bytes from a random device, nor do we want to use buffered
134           * I/O because we will waste system entropy.
135           */
136          bytes = (bytes == -1) ? 2048 : bytes; /* ok, is 2048 enough? */
137          setvbuf(in, NULL, _IONBF, 0); /* don't do buffered reads */
138        }
139#endif
140        for (;;)
141                {
142                if (bytes > 0)
143                        n = (bytes < BUFSIZE)?(int)bytes:BUFSIZE;
144                else
145                        n = BUFSIZE;
146                i=fread(buf,1,n,in);
147                if (i <= 0) break;
148#ifdef PURIFY
149                RAND_add(buf,i,(double)i);
150#else
151                /* even if n != i, use the full array */
152                RAND_add(buf,n,(double)i);
153#endif
154                ret+=i;
155                if (bytes > 0)
156                        {
157                        bytes-=n;
158                        if (bytes <= 0) break;
159                        }
160                }
161        fclose(in);
162        OPENSSL_cleanse(buf,BUFSIZE);
163err:
164        return(ret);
165        }
166
167int RAND_write_file(const char *file)
168        {
169        unsigned char buf[BUFSIZE];
170        int i,ret=0,rand_err=0;
171        FILE *out = NULL;
172        int n;
173        struct stat sb;
174       
175        i=stat(file,&sb);
176        if (i != -1) { 
177#if defined(S_IFBLK) && defined(S_IFCHR)
178          if (sb.st_mode & (S_IFBLK | S_IFCHR)) {
179            /* this file is a device. we don't write back to it.
180             * we "succeed" on the assumption this is some sort
181             * of random device. Otherwise attempting to write to
182             * and chmod the device causes problems.
183             */
184            return(1); 
185          }
186#endif
187        }
188
189#if defined(O_CREAT) && !defined(OPENSSL_SYS_WIN32) && !defined(OPENSSL_SYS_VMS)
190        {
191        /* For some reason Win32 can't write to files created this way */
192       
193        /* chmod(..., 0600) is too late to protect the file,
194         * permissions should be restrictive from the start */
195        int fd = open(file, O_CREAT, 0600);
196        if (fd != -1)
197                out = fdopen(fd, "wb");
198        }
199#endif
200
201#ifdef OPENSSL_SYS_VMS
202        /* VMS NOTE: Prior versions of this routine created a _new_
203         * version of the rand file for each call into this routine, then
204         * deleted all existing versions named ;-1, and finally renamed
205         * the current version as ';1'. Under concurrent usage, this
206         * resulted in an RMS race condition in rename() which could
207         * orphan files (see vms message help for RMS$_REENT). With the
208         * fopen() calls below, openssl/VMS now shares the top-level
209         * version of the rand file. Note that there may still be
210         * conditions where the top-level rand file is locked. If so, this
211         * code will then create a new version of the rand file. Without
212         * the delete and rename code, this can result in ascending file
213         * versions that stop at version 32767, and this routine will then
214         * return an error. The remedy for this is to recode the calling
215         * application to avoid concurrent use of the rand file, or
216         * synchronize usage at the application level. Also consider
217         * whether or not you NEED a persistent rand file in a concurrent
218         * use situation.
219         */
220
221        out = vms_fopen(file,"rb+",VMS_OPEN_ATTRS);
222        if (out == NULL)
223                out = vms_fopen(file,"wb",VMS_OPEN_ATTRS);
224#else
225        if (out == NULL)
226                out = fopen(file,"wb");
227#endif
228        if (out == NULL) goto err;
229
230#ifndef NO_CHMOD
231        chmod(file,0600);
232#endif
233        n=RAND_DATA;
234        for (;;)
235                {
236                i=(n > BUFSIZE)?BUFSIZE:n;
237                n-=BUFSIZE;
238                if (RAND_bytes(buf,i) <= 0)
239                        rand_err=1;
240                i=fwrite(buf,1,i,out);
241                if (i <= 0)
242                        {
243                        ret=0;
244                        break;
245                        }
246                ret+=i;
247                if (n <= 0) break;
248                }
249
250        fclose(out);
251        OPENSSL_cleanse(buf,BUFSIZE);
252err:
253        return (rand_err ? -1 : ret);
254        }
255
256const char *RAND_file_name(char *buf, size_t size)
257        {
258        char *s=NULL;
259        int ok = 0;
260#ifdef __OpenBSD__
261        struct stat sb;
262#endif
263
264        if (OPENSSL_issetugid() == 0)
265                s=getenv("RANDFILE");
266        if (s != NULL && *s && strlen(s) + 1 < size)
267                {
268                if (BUF_strlcpy(buf,s,size) >= size)
269                        return NULL;
270                }
271        else
272                {
273                if (OPENSSL_issetugid() == 0)
274                        s=getenv("HOME");
275#ifdef DEFAULT_HOME
276                if (s == NULL)
277                        {
278                        s = DEFAULT_HOME;
279                        }
280#endif
281                if (s && *s && strlen(s)+strlen(RFILE)+2 < size)
282                        {
283                        BUF_strlcpy(buf,s,size);
284#ifndef OPENSSL_SYS_VMS
285                        BUF_strlcat(buf,"/",size);
286#endif
287                        BUF_strlcat(buf,RFILE,size);
288                        ok = 1;
289                        }
290                else
291                        buf[0] = '\0'; /* no file name */
292                }
293
294#ifdef __OpenBSD__
295        /* given that all random loads just fail if the file can't be
296         * seen on a stat, we stat the file we're returning, if it
297         * fails, use /dev/arandom instead. this allows the user to
298         * use their own source for good random data, but defaults
299         * to something hopefully decent if that isn't available.
300         */
301
302        if (!ok)
303                if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) {
304                        return(NULL);
305                }       
306        if (stat(buf,&sb) == -1)
307                if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) {
308                        return(NULL);
309                }       
310
311#endif
312        return(buf);
313        }
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