1/*
2 * Copyright 1995-2019 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
15static int mem_write(BIO *h, const char *buf, int num);
16static int mem_read(BIO *h, char *buf, int size);
17static int mem_puts(BIO *h, const char *str);
18static int mem_gets(BIO *h, char *str, int size);
19static long mem_ctrl(BIO *h, int cmd, long arg1, void *arg2);
20static int mem_new(BIO *h);
21static int secmem_new(BIO *h);
22static int mem_free(BIO *data);
23static int mem_buf_free(BIO *data);
24static int mem_buf_sync(BIO *h);
25
26static 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
43static 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 */
66typedef 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
76const BIO_METHOD *BIO_s_mem(void)
77{
78    return &mem_method;
79}
80
81const BIO_METHOD *BIO_s_secmem(void)
82{
83    return(&secmem_method);
84}
85
86BIO *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
113static 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
136static int mem_new(BIO *bi)
137{
138    return mem_init(bi, 0L);
139}
140
141static int secmem_new(BIO *bi)
142{
143    return mem_init(bi, BUF_MEM_FLAG_SECURE);
144}
145
146static 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
161static 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 */
180static 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
194static 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
217static 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
245static 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[0]);
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
326static 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
364static 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