rand_egd.c revision 331638 
1/* crypto/rand/rand_egd.c */
2/* Written by Ulf Moeller and Lutz Jaenicke for the OpenSSL project. */
3/* ====================================================================
4 * Copyright (c) 1998-2000 The OpenSSL Project.  All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in
15 *    the documentation and/or other materials provided with the
16 *    distribution.
17 *
18 * 3. All advertising materials mentioning features or use of this
19 *    software must display the following acknowledgment:
20 *    "This product includes software developed by the OpenSSL Project
21 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
22 *
23 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
24 *    endorse or promote products derived from this software without
25 *    prior written permission. For written permission, please contact
26 *    openssl-core@openssl.org.
27 *
28 * 5. Products derived from this software may not be called "OpenSSL"
29 *    nor may "OpenSSL" appear in their names without prior written
30 *    permission of the OpenSSL Project.
31 *
32 * 6. Redistributions of any form whatsoever must retain the following
33 *    acknowledgment:
34 *    "This product includes software developed by the OpenSSL Project
35 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
36 *
37 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
38 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
39 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
40 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
41 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
42 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
43 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
44 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
45 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
46 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
47 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
48 * OF THE POSSIBILITY OF SUCH DAMAGE.
49 * ====================================================================
50 *
51 * This product includes cryptographic software written by Eric Young
52 * (eay@cryptsoft.com).  This product includes software written by Tim
53 * Hudson (tjh@cryptsoft.com).
54 *
55 */
56
57#include <openssl/e_os2.h>
58#include <openssl/rand.h>
59#include <openssl/buffer.h>
60
61/*-
62 * Query the EGD <URL: http://www.lothar.com/tech/crypto/>.
63 *
64 * This module supplies three routines:
65 *
66 * RAND_query_egd_bytes(path, buf, bytes)
67 *   will actually query "bytes" bytes of entropy form the egd-socket located
68 *   at path and will write them to buf (if supplied) or will directly feed
69 *   it to RAND_seed() if buf==NULL.
70 *   The number of bytes is not limited by the maximum chunk size of EGD,
71 *   which is 255 bytes. If more than 255 bytes are wanted, several chunks
72 *   of entropy bytes are requested. The connection is left open until the
73 *   query is competed.
74 *   RAND_query_egd_bytes() returns with
75 *     -1  if an error occured during connection or communication.
76 *     num the number of bytes read from the EGD socket. This number is either
77 *         the number of bytes requested or smaller, if the EGD pool is
78 *         drained and the daemon signals that the pool is empty.
79 *   This routine does not touch any RAND_status(). This is necessary, since
80 *   PRNG functions may call it during initialization.
81 *
82 * RAND_egd_bytes(path, bytes) will query "bytes" bytes and have them
83 *   used to seed the PRNG.
84 *   RAND_egd_bytes() is a wrapper for RAND_query_egd_bytes() with buf=NULL.
85 *   Unlike RAND_query_egd_bytes(), RAND_status() is used to test the
86 *   seed status so that the return value can reflect the seed state:
87 *     -1  if an error occured during connection or communication _or_
88 *         if the PRNG has still not received the required seeding.
89 *     num the number of bytes read from the EGD socket. This number is either
90 *         the number of bytes requested or smaller, if the EGD pool is
91 *         drained and the daemon signals that the pool is empty.
92 *
93 * RAND_egd(path) will query 255 bytes and use the bytes retreived to seed
94 *   the PRNG.
95 *   RAND_egd() is a wrapper for RAND_egd_bytes() with numbytes=255.
96 */
97
98#if defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VMS) || defined(OPENSSL_SYS_MSDOS) || defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYS_NETWARE) || defined(OPENSSL_SYS_VOS) || defined(OPENSSL_SYS_BEOS)
99int RAND_query_egd_bytes(const char *path, unsigned char *buf, int bytes)
100{
101    return (-1);
102}
103
104int RAND_egd(const char *path)
105{
106    return (-1);
107}
108
109int RAND_egd_bytes(const char *path, int bytes)
110{
111    return (-1);
112}
113#else
114# include <openssl/opensslconf.h>
115# include OPENSSL_UNISTD
116# include <stddef.h>
117# include <sys/types.h>
118# include <sys/socket.h>
119# ifndef NO_SYS_UN_H
120#  ifdef OPENSSL_SYS_VXWORKS
121#   include <streams/un.h>
122#  else
123#   include <sys/un.h>
124#  endif
125# else
126struct sockaddr_un {
127    short sun_family;           /* AF_UNIX */
128    char sun_path[108];         /* path name (gag) */
129};
130# endif                         /* NO_SYS_UN_H */
131# include <string.h>
132# include <errno.h>
133
134# ifndef offsetof
135#  define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
136# endif
137
138int RAND_query_egd_bytes(const char *path, unsigned char *buf, int bytes)
139{
140    int ret = 0;
141    struct sockaddr_un addr;
142    int len, num, numbytes;
143    int fd = -1;
144    int success;
145    unsigned char egdbuf[2], tempbuf[255], *retrievebuf;
146
147    memset(&addr, 0, sizeof(addr));
148    addr.sun_family = AF_UNIX;
149    if (strlen(path) >= sizeof(addr.sun_path))
150        return (-1);
151    BUF_strlcpy(addr.sun_path, path, sizeof(addr.sun_path));
152    len = offsetof(struct sockaddr_un, sun_path) + strlen(path);
153    fd = socket(AF_UNIX, SOCK_STREAM, 0);
154    if (fd == -1)
155        return (-1);
156    success = 0;
157    while (!success) {
158        if (connect(fd, (struct sockaddr *)&addr, len) == 0)
159            success = 1;
160        else {
161            switch (errno) {
162# ifdef EINTR
163            case EINTR:
164# endif
165# ifdef EAGAIN
166            case EAGAIN:
167# endif
168# ifdef EINPROGRESS
169            case EINPROGRESS:
170# endif
171# ifdef EALREADY
172            case EALREADY:
173# endif
174                /* No error, try again */
175                break;
176# ifdef EISCONN
177            case EISCONN:
178                success = 1;
179                break;
180# endif
181            default:
182                goto err;       /* failure */
183            }
184        }
185    }
186
187    while (bytes > 0) {
188        egdbuf[0] = 1;
189        egdbuf[1] = bytes < 255 ? bytes : 255;
190        numbytes = 0;
191        while (numbytes != 2) {
192            num = write(fd, egdbuf + numbytes, 2 - numbytes);
193            if (num >= 0)
194                numbytes += num;
195            else {
196                switch (errno) {
197# ifdef EINTR
198                case EINTR:
199# endif
200# ifdef EAGAIN
201                case EAGAIN:
202# endif
203                    /* No error, try again */
204                    break;
205                default:
206                    ret = -1;
207                    goto err;   /* failure */
208                }
209            }
210        }
211        numbytes = 0;
212        while (numbytes != 1) {
213            num = read(fd, egdbuf, 1);
214            if (num == 0)
215                goto err;       /* descriptor closed */
216            else if (num > 0)
217                numbytes += num;
218            else {
219                switch (errno) {
220# ifdef EINTR
221                case EINTR:
222# endif
223# ifdef EAGAIN
224                case EAGAIN:
225# endif
226                    /* No error, try again */
227                    break;
228                default:
229                    ret = -1;
230                    goto err;   /* failure */
231                }
232            }
233        }
234        if (egdbuf[0] == 0)
235            goto err;
236        if (buf)
237            retrievebuf = buf + ret;
238        else
239            retrievebuf = tempbuf;
240        numbytes = 0;
241        while (numbytes != egdbuf[0]) {
242            num = read(fd, retrievebuf + numbytes, egdbuf[0] - numbytes);
243            if (num == 0)
244                goto err;       /* descriptor closed */
245            else if (num > 0)
246                numbytes += num;
247            else {
248                switch (errno) {
249# ifdef EINTR
250                case EINTR:
251# endif
252# ifdef EAGAIN
253                case EAGAIN:
254# endif
255                    /* No error, try again */
256                    break;
257                default:
258                    ret = -1;
259                    goto err;   /* failure */
260                }
261            }
262        }
263        ret += egdbuf[0];
264        bytes -= egdbuf[0];
265        if (!buf)
266            RAND_seed(tempbuf, egdbuf[0]);
267    }
268 err:
269    if (fd != -1)
270        close(fd);
271    return (ret);
272}
273
274int RAND_egd_bytes(const char *path, int bytes)
275{
276    int num, ret = 0;
277
278    num = RAND_query_egd_bytes(path, NULL, bytes);
279    if (num < 1)
280        goto err;
281    if (RAND_status() == 1)
282        ret = num;
283 err:
284    return (ret);
285}
286
287int RAND_egd(const char *path)
288{
289    return (RAND_egd_bytes(path, 255));
290}
291
292#endif
293