randfile.c revision 55714 
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#include <sys/types.h>
64#include <sys/stat.h>
65#include <sys/types.h>
66
67#include "openssl/e_os.h"
68
69#include <openssl/rand.h>
70
71#undef BUFSIZE
72#define BUFSIZE	1024
73#define RAND_DATA 1024
74
75/* #define RFILE ".rand" - defined in ../../e_os.h */
76
77int RAND_load_file(const char *file, long bytes)
78	{
79	MS_STATIC unsigned char buf[BUFSIZE];
80	struct stat sb;
81	int i,ret=0,n;
82	FILE *in;
83
84	if (file == NULL) return(0);
85
86	i=stat(file,&sb);
87	/* If the state fails, put some crap in anyway */
88	RAND_seed(&sb,sizeof(sb));
89	ret+=sizeof(sb);
90	if (i < 0) return(0);
91	if (bytes <= 0) return(ret);
92
93	in=fopen(file,"rb");
94	if (in == NULL) goto err;
95	for (;;)
96		{
97		n=(bytes < BUFSIZE)?(int)bytes:BUFSIZE;
98		i=fread(buf,1,n,in);
99		if (i <= 0) break;
100		/* even if n != i, use the full array */
101		RAND_seed(buf,n);
102		ret+=i;
103		bytes-=n;
104		if (bytes <= 0) break;
105		}
106	fclose(in);
107	memset(buf,0,BUFSIZE);
108err:
109	return(ret);
110	}
111
112int RAND_write_file(const char *file)
113	{
114	unsigned char buf[BUFSIZE];
115	int i,ret=0;
116	FILE *out;
117	int n;
118
119	/* Under VMS, fopen(file, "wb") will craete a new version of the
120	   same file.  This is not good, so let's try updating an existing
121	   one, and create file only if it doesn't already exist.  This
122	   should be completely harmless on system that have no file
123	   versions.					-- Richard Levitte */
124	out=fopen(file,"rb+");
125	if (out == NULL && errno == ENOENT)
126		{
127		errno = 0;
128		out=fopen(file,"wb");
129		}
130	if (out == NULL) goto err;
131	chmod(file,0600);
132	n=RAND_DATA;
133	for (;;)
134		{
135		i=(n > BUFSIZE)?BUFSIZE:n;
136		n-=BUFSIZE;
137		RAND_bytes(buf,i);
138		i=fwrite(buf,1,i,out);
139		if (i <= 0)
140			{
141			ret=0;
142			break;
143			}
144		ret+=i;
145		if (n <= 0) break;
146		}
147	fclose(out);
148	memset(buf,0,BUFSIZE);
149err:
150	return(ret);
151	}
152
153char *RAND_file_name(char *buf, int size)
154	{
155	char *s;
156	char *ret=NULL;
157
158	s=getenv("RANDFILE");
159	if (s != NULL)
160		{
161		strncpy(buf,s,size-1);
162		buf[size-1]='\0';
163		ret=buf;
164		}
165	else
166		{
167		s=getenv("HOME");
168		if (s == NULL) return(RFILE);
169		if (((int)(strlen(s)+strlen(RFILE)+2)) > size)
170			return(RFILE);
171		strcpy(buf,s);
172#ifndef VMS
173		strcat(buf,"/");
174#endif
175		strcat(buf,RFILE);
176		ret=buf;
177		}
178	return(ret);
179	}
180