xref: /freebsd/crypto/openssl/crypto/bio/bss_mem.c (revision 29fc4075e69fd27de0cded313ac6000165d99f8b) 
1 /*
2  * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the OpenSSL license (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 
15 static int mem_write(BIO *h, const char *buf, int num);
16 static int mem_read(BIO *h, char *buf, int size);
17 static int mem_puts(BIO *h, const char *str);
18 static int mem_gets(BIO *h, char *str, int size);
19 static long mem_ctrl(BIO *h, int cmd, long arg1, void *arg2);
20 static int mem_new(BIO *h);
21 static int secmem_new(BIO *h);
22 static int mem_free(BIO *data);
23 static int mem_buf_free(BIO *data);
24 static int mem_buf_sync(BIO *h);
25 
26 static const BIO_METHOD mem_method = {
27     BIO_TYPE_MEM,
28     "memory buffer",
29     /* TODO: Convert to new style write function */
30     bwrite_conv,
31     mem_write,
32     /* TODO: Convert to new style read function */
33     bread_conv,
34     mem_read,
35     mem_puts,
36     mem_gets,
37     mem_ctrl,
38     mem_new,
39     mem_free,
40     NULL,                      /* mem_callback_ctrl */
41 };
42 
43 static const BIO_METHOD secmem_method = {
44     BIO_TYPE_MEM,
45     "secure memory buffer",
46     /* TODO: Convert to new style write function */
47     bwrite_conv,
48     mem_write,
49     /* TODO: Convert to new style read function */
50     bread_conv,
51     mem_read,
52     mem_puts,
53     mem_gets,
54     mem_ctrl,
55     secmem_new,
56     mem_free,
57     NULL,                      /* mem_callback_ctrl */
58 };
59 
60 /*
61  * BIO memory stores buffer and read pointer
62  * however the roles are different for read only BIOs.
63  * In that case the readp just stores the original state
64  * to be used for reset.
65  */
66 typedef struct bio_buf_mem_st {
67     struct buf_mem_st *buf;   /* allocated buffer */
68     struct buf_mem_st *readp; /* read pointer */
69 } BIO_BUF_MEM;
70 
71 /*
72  * bio->num is used to hold the value to return on 'empty', if it is 0,
73  * should_retry is not set
74  */
75 
76 const BIO_METHOD *BIO_s_mem(void)
77 {
78     return &mem_method;
79 }
80 
81 const BIO_METHOD *BIO_s_secmem(void)
82 {
83     return(&secmem_method);
84 }
85 
86 BIO *BIO_new_mem_buf(const void *buf, int len)
87 {
88     BIO *ret;
89     BUF_MEM *b;
90     BIO_BUF_MEM *bb;
91     size_t sz;
92 
93     if (buf == NULL) {
94         BIOerr(BIO_F_BIO_NEW_MEM_BUF, BIO_R_NULL_PARAMETER);
95         return NULL;
96     }
97     sz = (len < 0) ? strlen(buf) : (size_t)len;
98     if ((ret = BIO_new(BIO_s_mem())) == NULL)
99         return NULL;
100     bb = (BIO_BUF_MEM *)ret->ptr;
101     b = bb->buf;
102     /* Cast away const and trust in the MEM_RDONLY flag. */
103     b->data = (void *)buf;
104     b->length = sz;
105     b->max = sz;
106     *bb->readp = *bb->buf;
107     ret->flags |= BIO_FLAGS_MEM_RDONLY;
108     /* Since this is static data retrying won't help */
109     ret->num = 0;
110     return ret;
111 }
112 
113 static int mem_init(BIO *bi, unsigned long flags)
114 {
115     BIO_BUF_MEM *bb = OPENSSL_zalloc(sizeof(*bb));
116 
117     if (bb == NULL)
118         return 0;
119     if ((bb->buf = BUF_MEM_new_ex(flags)) == NULL) {
120         OPENSSL_free(bb);
121         return 0;
122     }
123     if ((bb->readp = OPENSSL_zalloc(sizeof(*bb->readp))) == NULL) {
124         BUF_MEM_free(bb->buf);
125         OPENSSL_free(bb);
126         return 0;
127     }
128     *bb->readp = *bb->buf;
129     bi->shutdown = 1;
130     bi->init = 1;
131     bi->num = -1;
132     bi->ptr = (char *)bb;
133     return 1;
134 }
135 
136 static int mem_new(BIO *bi)
137 {
138     return mem_init(bi, 0L);
139 }
140 
141 static int secmem_new(BIO *bi)
142 {
143     return mem_init(bi, BUF_MEM_FLAG_SECURE);
144 }
145 
146 static int mem_free(BIO *a)
147 {
148     BIO_BUF_MEM *bb;
149 
150     if (a == NULL)
151         return 0;
152 
153     bb = (BIO_BUF_MEM *)a->ptr;
154     if (!mem_buf_free(a))
155         return 0;
156     OPENSSL_free(bb->readp);
157     OPENSSL_free(bb);
158     return 1;
159 }
160 
161 static int mem_buf_free(BIO *a)
162 {
163     if (a == NULL)
164         return 0;
165 
166     if (a->shutdown && a->init && a->ptr != NULL) {
167         BIO_BUF_MEM *bb = (BIO_BUF_MEM *)a->ptr;
168         BUF_MEM *b = bb->buf;
169 
170         if (a->flags & BIO_FLAGS_MEM_RDONLY)
171             b->data = NULL;
172         BUF_MEM_free(b);
173     }
174     return 1;
175 }
176 
177 /*
178  * Reallocate memory buffer if read pointer differs
179  */
180 static int mem_buf_sync(BIO *b)
181 {
182     if (b != NULL && b->init != 0 && b->ptr != NULL) {
183         BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)b->ptr;
184 
185         if (bbm->readp->data != bbm->buf->data) {
186             memmove(bbm->buf->data, bbm->readp->data, bbm->readp->length);
187             bbm->buf->length = bbm->readp->length;
188             bbm->readp->data = bbm->buf->data;
189         }
190     }
191     return 0;
192 }
193 
194 static int mem_read(BIO *b, char *out, int outl)
195 {
196     int ret = -1;
197     BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)b->ptr;
198     BUF_MEM *bm = bbm->readp;
199 
200     if (b->flags & BIO_FLAGS_MEM_RDONLY)
201         bm = bbm->buf;
202     BIO_clear_retry_flags(b);
203     ret = (outl >= 0 && (size_t)outl > bm->length) ? (int)bm->length : outl;
204     if ((out != NULL) && (ret > 0)) {
205         memcpy(out, bm->data, ret);
206         bm->length -= ret;
207         bm->max -= ret;
208         bm->data += ret;
209     } else if (bm->length == 0) {
210         ret = b->num;
211         if (ret != 0)
212             BIO_set_retry_read(b);
213     }
214     return ret;
215 }
216 
217 static int mem_write(BIO *b, const char *in, int inl)
218 {
219     int ret = -1;
220     int blen;
221     BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)b->ptr;
222 
223     if (in == NULL) {
224         BIOerr(BIO_F_MEM_WRITE, BIO_R_NULL_PARAMETER);
225         goto end;
226     }
227     if (b->flags & BIO_FLAGS_MEM_RDONLY) {
228         BIOerr(BIO_F_MEM_WRITE, BIO_R_WRITE_TO_READ_ONLY_BIO);
229         goto end;
230     }
231     BIO_clear_retry_flags(b);
232     if (inl == 0)
233         return 0;
234     blen = bbm->readp->length;
235     mem_buf_sync(b);
236     if (BUF_MEM_grow_clean(bbm->buf, blen + inl) == 0)
237         goto end;
238     memcpy(bbm->buf->data + blen, in, inl);
239     *bbm->readp = *bbm->buf;
240     ret = inl;
241  end:
242     return ret;
243 }
244 
245 static long mem_ctrl(BIO *b, int cmd, long num, void *ptr)
246 {
247     long ret = 1;
248     char **pptr;
249     BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)b->ptr;
250     BUF_MEM *bm;
251 
252     if (b->flags & BIO_FLAGS_MEM_RDONLY)
253         bm = bbm->buf;
254     else
255         bm = bbm->readp;
256 
257     switch (cmd) {
258     case BIO_CTRL_RESET:
259         bm = bbm->buf;
260         if (bm->data != NULL) {
261             if (!(b->flags & BIO_FLAGS_MEM_RDONLY)) {
262                 if (!(b->flags & BIO_FLAGS_NONCLEAR_RST)) {
263                     memset(bm->data, 0, bm->max);
264                     bm->length = 0;
265                 }
266                 *bbm->readp = *bbm->buf;
267             } else {
268                 /* For read only case just reset to the start again */
269                 *bbm->buf = *bbm->readp;
270             }
271         }
272         break;
273     case BIO_CTRL_EOF:
274         ret = (long)(bm->length == 0);
275         break;
276     case BIO_C_SET_BUF_MEM_EOF_RETURN:
277         b->num = (int)num;
278         break;
279     case BIO_CTRL_INFO:
280         ret = (long)bm->length;
281         if (ptr != NULL) {
282             pptr = (char **)ptr;
283             *pptr = (char *)bm->data;
284         }
285         break;
286     case BIO_C_SET_BUF_MEM:
287         mem_buf_free(b);
288         b->shutdown = (int)num;
289         bbm->buf = ptr;
290         *bbm->readp = *bbm->buf;
291         break;
292     case BIO_C_GET_BUF_MEM_PTR:
293         if (ptr != NULL) {
294             if (!(b->flags & BIO_FLAGS_MEM_RDONLY))
295                 mem_buf_sync(b);
296             bm = bbm->buf;
297             pptr = (char **)ptr;
298             *pptr = (char *)bm;
299         }
300         break;
301     case BIO_CTRL_GET_CLOSE:
302         ret = (long)b->shutdown;
303         break;
304     case BIO_CTRL_SET_CLOSE:
305         b->shutdown = (int)num;
306         break;
307     case BIO_CTRL_WPENDING:
308         ret = 0L;
309         break;
310     case BIO_CTRL_PENDING:
311         ret = (long)bm->length;
312         break;
313     case BIO_CTRL_DUP:
314     case BIO_CTRL_FLUSH:
315         ret = 1;
316         break;
317     case BIO_CTRL_PUSH:
318     case BIO_CTRL_POP:
319     default:
320         ret = 0;
321         break;
322     }
323     return ret;
324 }
325 
326 static int mem_gets(BIO *bp, char *buf, int size)
327 {
328     int i, j;
329     int ret = -1;
330     char *p;
331     BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)bp->ptr;
332     BUF_MEM *bm = bbm->readp;
333 
334     if (bp->flags & BIO_FLAGS_MEM_RDONLY)
335         bm = bbm->buf;
336     BIO_clear_retry_flags(bp);
337     j = bm->length;
338     if ((size - 1) < j)
339         j = size - 1;
340     if (j <= 0) {
341         *buf = '\0';
342         return 0;
343     }
344     p = bm->data;
345     for (i = 0; i < j; i++) {
346         if (p[i] == '\n') {
347             i++;
348             break;
349         }
350     }
351 
352     /*
353      * i is now the max num of bytes to copy, either j or up to
354      * and including the first newline
355      */
356 
357     i = mem_read(bp, buf, i);
358     if (i > 0)
359         buf[i] = '\0';
360     ret = i;
361     return ret;
362 }
363 
364 static int mem_puts(BIO *bp, const char *str)
365 {
366     int n, ret;
367 
368     n = strlen(str);
369     ret = mem_write(bp, str, n);
370     /* memory semantics is that it will always work */
371     return ret;
372 }
373