randfile.c revision 79998 
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#include <errno.h>
60#include <stdio.h>
61#include <stdlib.h>
62#include <string.h>
63
64#ifdef VMS
65#include <unixio.h>
66#endif
67#ifndef NO_SYS_TYPES_H
68# include <sys/types.h>
69#endif
70#ifdef MAC_OS_pre_X
71# include <stat.h>
72#else
73# include <sys/stat.h>
74#endif
75
76#include "openssl/e_os.h"
77#include <openssl/crypto.h>
78#include <openssl/rand.h>
79
80#undef BUFSIZE
81#define BUFSIZE	1024
82#define RAND_DATA 1024
83
84/* #define RFILE ".rnd" - defined in ../../e_os.h */
85
86/* Note that these functions are intended for seed files only.
87 * Entropy devices and EGD sockets are handled in rand_unix.c */
88
89int RAND_load_file(const char *file, long bytes)
90	{
91	/* If bytes >= 0, read up to 'bytes' bytes.
92	 * if bytes == -1, read complete file. */
93
94	MS_STATIC unsigned char buf[BUFSIZE];
95	struct stat sb;
96	int i,ret=0,n;
97	FILE *in;
98
99	if (file == NULL) return(0);
100
101	i=stat(file,&sb);
102	/* If the state fails, put some crap in anyway */
103	RAND_add(&sb,sizeof(sb),0);
104	if (i < 0) return(0);
105	if (bytes == 0) return(ret);
106
107	in=fopen(file,"rb");
108	if (in == NULL) goto err;
109	for (;;)
110		{
111		if (bytes > 0)
112			n = (bytes < BUFSIZE)?(int)bytes:BUFSIZE;
113		else
114			n = BUFSIZE;
115		i=fread(buf,1,n,in);
116		if (i <= 0) break;
117		/* even if n != i, use the full array */
118		RAND_add(buf,n,i);
119		ret+=i;
120		if (bytes > 0)
121			{
122			bytes-=n;
123			if (bytes <= 0) break;
124			}
125		}
126	fclose(in);
127	memset(buf,0,BUFSIZE);
128err:
129	return(ret);
130	}
131
132int RAND_write_file(const char *file)
133	{
134	unsigned char buf[BUFSIZE];
135	int i,ret=0,rand_err=0;
136	FILE *out = NULL;
137	int n;
138
139#if defined(O_CREAT) && !defined(WIN32)
140	/* For some reason Win32 can't write to files created this way */
141
142	/* chmod(..., 0600) is too late to protect the file,
143	 * permissions should be restrictive from the start */
144	int fd = open(file, O_CREAT, 0600);
145	if (fd != -1)
146		out = fdopen(fd, "wb");
147#endif
148	if (out == NULL)
149		out = fopen(file,"wb");
150	if (out == NULL) goto err;
151
152#ifndef NO_CHMOD
153	chmod(file,0600);
154#endif
155	n=RAND_DATA;
156	for (;;)
157		{
158		i=(n > BUFSIZE)?BUFSIZE:n;
159		n-=BUFSIZE;
160		if (RAND_bytes(buf,i) <= 0)
161			rand_err=1;
162		i=fwrite(buf,1,i,out);
163		if (i <= 0)
164			{
165			ret=0;
166			break;
167			}
168		ret+=i;
169		if (n <= 0) break;
170                }
171#ifdef VMS
172	/* Try to delete older versions of the file, until there aren't
173	   any */
174	{
175	char *tmpf;
176
177	tmpf = OPENSSL_malloc(strlen(file) + 4);  /* to add ";-1" and a nul */
178	if (tmpf)
179		{
180		strcpy(tmpf, file);
181		strcat(tmpf, ";-1");
182		while(delete(tmpf) == 0)
183			;
184		rename(file,";1"); /* Make sure it's version 1, or we
185				      will reach the limit (32767) at
186				      some point... */
187		}
188	}
189#endif /* VMS */
190
191	fclose(out);
192	memset(buf,0,BUFSIZE);
193err:
194	return (rand_err ? -1 : ret);
195	}
196
197const char *RAND_file_name(char *buf, size_t size)
198	{
199	char *s=NULL;
200	char *ret=NULL;
201
202	if (OPENSSL_issetugid() == 0)
203		s=getenv("RANDFILE");
204	if (s != NULL)
205		{
206		strncpy(buf,s,size-1);
207		buf[size-1]='\0';
208		ret=buf;
209		}
210	else
211		{
212		if (OPENSSL_issetugid() == 0)
213			s=getenv("HOME");
214#ifdef DEFAULT_HOME
215		if (s == NULL)
216			{
217			s = DEFAULT_HOME;
218			}
219#endif
220		if (s != NULL && (strlen(s)+strlen(RFILE)+2 < size))
221			{
222			strcpy(buf,s);
223#ifndef VMS
224			strcat(buf,"/");
225#endif
226			strcat(buf,RFILE);
227			ret=buf;
228			}
229		else
230		  	buf[0] = '\0'; /* no file name */
231		}
232	return(ret);
233	}
234