xref: /openssl/crypto/bio/bf_nbio.c (revision e077455e)
1 /*
2  * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 #include <stdio.h>
11 #include <errno.h>
12 #include "bio_local.h"
13 #include "internal/cryptlib.h"
14 #include <openssl/rand.h>
15 
16 /*
17  * BIO_put and BIO_get both add to the digest, BIO_gets returns the digest
18  */
19 
20 static int nbiof_write(BIO *h, const char *buf, int num);
21 static int nbiof_read(BIO *h, char *buf, int size);
22 static int nbiof_puts(BIO *h, const char *str);
23 static int nbiof_gets(BIO *h, char *str, int size);
24 static long nbiof_ctrl(BIO *h, int cmd, long arg1, void *arg2);
25 static int nbiof_new(BIO *h);
26 static int nbiof_free(BIO *data);
27 static long nbiof_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
28 typedef struct nbio_test_st {
29     /* only set if we sent a 'should retry' error */
30     int lrn;
31     int lwn;
32 } NBIO_TEST;
33 
34 static const BIO_METHOD methods_nbiof = {
35     BIO_TYPE_NBIO_TEST,
36     "non-blocking IO test filter",
37     bwrite_conv,
38     nbiof_write,
39     bread_conv,
40     nbiof_read,
41     nbiof_puts,
42     nbiof_gets,
43     nbiof_ctrl,
44     nbiof_new,
45     nbiof_free,
46     nbiof_callback_ctrl,
47 };
48 
BIO_f_nbio_test(void)49 const BIO_METHOD *BIO_f_nbio_test(void)
50 {
51     return &methods_nbiof;
52 }
53 
nbiof_new(BIO * bi)54 static int nbiof_new(BIO *bi)
55 {
56     NBIO_TEST *nt;
57 
58     if ((nt = OPENSSL_zalloc(sizeof(*nt))) == NULL)
59         return 0;
60     nt->lrn = -1;
61     nt->lwn = -1;
62     bi->ptr = (char *)nt;
63     bi->init = 1;
64     return 1;
65 }
66 
nbiof_free(BIO * a)67 static int nbiof_free(BIO *a)
68 {
69     if (a == NULL)
70         return 0;
71     OPENSSL_free(a->ptr);
72     a->ptr = NULL;
73     a->init = 0;
74     a->flags = 0;
75     return 1;
76 }
77 
nbiof_read(BIO * b,char * out,int outl)78 static int nbiof_read(BIO *b, char *out, int outl)
79 {
80     int ret = 0;
81     int num;
82     unsigned char n;
83 
84     if (out == NULL)
85         return 0;
86     if (b->next_bio == NULL)
87         return 0;
88 
89     BIO_clear_retry_flags(b);
90     if (RAND_priv_bytes(&n, 1) <= 0)
91         return -1;
92     num = (n & 0x07);
93 
94     if (outl > num)
95         outl = num;
96 
97     if (num == 0) {
98         ret = -1;
99         BIO_set_retry_read(b);
100     } else {
101         ret = BIO_read(b->next_bio, out, outl);
102         if (ret < 0)
103             BIO_copy_next_retry(b);
104     }
105     return ret;
106 }
107 
nbiof_write(BIO * b,const char * in,int inl)108 static int nbiof_write(BIO *b, const char *in, int inl)
109 {
110     NBIO_TEST *nt;
111     int ret = 0;
112     int num;
113     unsigned char n;
114 
115     if ((in == NULL) || (inl <= 0))
116         return 0;
117     if (b->next_bio == NULL)
118         return 0;
119     nt = (NBIO_TEST *)b->ptr;
120 
121     BIO_clear_retry_flags(b);
122 
123     if (nt->lwn > 0) {
124         num = nt->lwn;
125         nt->lwn = 0;
126     } else {
127         if (RAND_priv_bytes(&n, 1) <= 0)
128             return -1;
129         num = (n & 7);
130     }
131 
132     if (inl > num)
133         inl = num;
134 
135     if (num == 0) {
136         ret = -1;
137         BIO_set_retry_write(b);
138     } else {
139         ret = BIO_write(b->next_bio, in, inl);
140         if (ret < 0) {
141             BIO_copy_next_retry(b);
142             nt->lwn = inl;
143         }
144     }
145     return ret;
146 }
147 
nbiof_ctrl(BIO * b,int cmd,long num,void * ptr)148 static long nbiof_ctrl(BIO *b, int cmd, long num, void *ptr)
149 {
150     long ret;
151 
152     if (b->next_bio == NULL)
153         return 0;
154     switch (cmd) {
155     case BIO_C_DO_STATE_MACHINE:
156         BIO_clear_retry_flags(b);
157         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
158         BIO_copy_next_retry(b);
159         break;
160     case BIO_CTRL_DUP:
161         ret = 0L;
162         break;
163     default:
164         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
165         break;
166     }
167     return ret;
168 }
169 
nbiof_callback_ctrl(BIO * b,int cmd,BIO_info_cb * fp)170 static long nbiof_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
171 {
172     if (b->next_bio == NULL)
173         return 0;
174     return BIO_callback_ctrl(b->next_bio, cmd, fp);
175 }
176 
nbiof_gets(BIO * bp,char * buf,int size)177 static int nbiof_gets(BIO *bp, char *buf, int size)
178 {
179     if (bp->next_bio == NULL)
180         return 0;
181     return BIO_gets(bp->next_bio, buf, size);
182 }
183 
nbiof_puts(BIO * bp,const char * str)184 static int nbiof_puts(BIO *bp, const char *str)
185 {
186     if (bp->next_bio == NULL)
187         return 0;
188     return BIO_puts(bp->next_bio, str);
189 }
190