xref: /openbsd/lib/libcrypto/bio/bf_nbio.c (revision acf64401)
1 /* $OpenBSD: bf_nbio.c,v 1.23 2023/07/05 21:23:37 beck Exp $ */
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 
63 #include <openssl/bio.h>
64 
65 #include "bio_local.h"
66 
67 /* BIO_put and BIO_get both add to the digest,
68  * BIO_gets returns the digest */
69 
70 static int nbiof_write(BIO *h, const char *buf, int num);
71 static int nbiof_read(BIO *h, char *buf, int size);
72 static int nbiof_puts(BIO *h, const char *str);
73 static int nbiof_gets(BIO *h, char *str, int size);
74 static long nbiof_ctrl(BIO *h, int cmd, long arg1, void *arg2);
75 static int nbiof_new(BIO *h);
76 static int nbiof_free(BIO *data);
77 static long nbiof_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
78 
79 typedef struct nbio_test_st {
80 	/* only set if we sent a 'should retry' error */
81 	int lrn;
82 	int lwn;
83 } NBIO_TEST;
84 
85 static const BIO_METHOD methods_nbiof = {
86 	.type = BIO_TYPE_NBIO_TEST,
87 	.name = "non-blocking IO test filter",
88 	.bwrite = nbiof_write,
89 	.bread = nbiof_read,
90 	.bputs = nbiof_puts,
91 	.bgets = nbiof_gets,
92 	.ctrl = nbiof_ctrl,
93 	.create = nbiof_new,
94 	.destroy = nbiof_free,
95 	.callback_ctrl = nbiof_callback_ctrl
96 };
97 
98 const BIO_METHOD *
BIO_f_nbio_test(void)99 BIO_f_nbio_test(void)
100 {
101 	return (&methods_nbiof);
102 }
103 LCRYPTO_ALIAS(BIO_f_nbio_test);
104 
105 static int
nbiof_new(BIO * bi)106 nbiof_new(BIO *bi)
107 {
108 	NBIO_TEST *nt;
109 
110 	if (!(nt = malloc(sizeof(NBIO_TEST))))
111 		return (0);
112 	nt->lrn = -1;
113 	nt->lwn = -1;
114 	bi->ptr = (char *)nt;
115 	bi->init = 1;
116 	bi->flags = 0;
117 	return (1);
118 }
119 
120 static int
nbiof_free(BIO * a)121 nbiof_free(BIO *a)
122 {
123 	if (a == NULL)
124 		return (0);
125 	free(a->ptr);
126 	a->ptr = NULL;
127 	a->init = 0;
128 	a->flags = 0;
129 	return (1);
130 }
131 
132 static int
nbiof_read(BIO * b,char * out,int outl)133 nbiof_read(BIO *b, char *out, int outl)
134 {
135 	int ret = 0;
136 	int num;
137 	unsigned char n;
138 
139 	if (out == NULL)
140 		return (0);
141 	if (b->next_bio == NULL)
142 		return (0);
143 
144 	BIO_clear_retry_flags(b);
145 
146 	arc4random_buf(&n, 1);
147 	num = (n & 0x07);
148 
149 	if (outl > num)
150 		outl = num;
151 
152 	if (num == 0) {
153 		ret = -1;
154 		BIO_set_retry_read(b);
155 	} else {
156 		ret = BIO_read(b->next_bio, out, outl);
157 		if (ret < 0)
158 			BIO_copy_next_retry(b);
159 	}
160 	return (ret);
161 }
162 
163 static int
nbiof_write(BIO * b,const char * in,int inl)164 nbiof_write(BIO *b, const char *in, int inl)
165 {
166 	NBIO_TEST *nt;
167 	int ret = 0;
168 	int num;
169 	unsigned char n;
170 
171 	if ((in == NULL) || (inl <= 0))
172 		return (0);
173 	if (b->next_bio == NULL)
174 		return (0);
175 	nt = (NBIO_TEST *)b->ptr;
176 
177 	BIO_clear_retry_flags(b);
178 
179 	if (nt->lwn > 0) {
180 		num = nt->lwn;
181 		nt->lwn = 0;
182 	} else {
183 		arc4random_buf(&n, 1);
184 		num = (n&7);
185 	}
186 
187 	if (inl > num)
188 		inl = num;
189 
190 	if (num == 0) {
191 		ret = -1;
192 		BIO_set_retry_write(b);
193 	} else {
194 		ret = BIO_write(b->next_bio, in, inl);
195 		if (ret < 0) {
196 			BIO_copy_next_retry(b);
197 			nt->lwn = inl;
198 		}
199 	}
200 	return (ret);
201 }
202 
203 static long
nbiof_ctrl(BIO * b,int cmd,long num,void * ptr)204 nbiof_ctrl(BIO *b, int cmd, long num, void *ptr)
205 {
206 	long ret;
207 
208 	if (b->next_bio == NULL)
209 		return (0);
210 	switch (cmd) {
211 	case BIO_C_DO_STATE_MACHINE:
212 		BIO_clear_retry_flags(b);
213 		ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
214 		BIO_copy_next_retry(b);
215 		break;
216 	case BIO_CTRL_DUP:
217 		ret = 0L;
218 		break;
219 	default:
220 		ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
221 		break;
222 	}
223 	return (ret);
224 }
225 
226 static long
nbiof_callback_ctrl(BIO * b,int cmd,BIO_info_cb * fp)227 nbiof_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
228 {
229 	long ret = 1;
230 
231 	if (b->next_bio == NULL)
232 		return (0);
233 	switch (cmd) {
234 	default:
235 		ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
236 		break;
237 	}
238 	return (ret);
239 }
240 
241 static int
nbiof_gets(BIO * bp,char * buf,int size)242 nbiof_gets(BIO *bp, char *buf, int size)
243 {
244 	if (bp->next_bio == NULL)
245 		return (0);
246 	return (BIO_gets(bp->next_bio, buf, size));
247 }
248 
249 static int
nbiof_puts(BIO * bp,const char * str)250 nbiof_puts(BIO *bp, const char *str)
251 {
252 	if (bp->next_bio == NULL)
253 		return (0);
254 	return (BIO_puts(bp->next_bio, str));
255 }
256