1/*
2 * Copyright 1995-2016 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 buffer_write(BIO *h, const char *buf, int num);
16static int buffer_read(BIO *h, char *buf, int size);
17static int buffer_puts(BIO *h, const char *str);
18static int buffer_gets(BIO *h, char *str, int size);
19static long buffer_ctrl(BIO *h, int cmd, long arg1, void *arg2);
20static int buffer_new(BIO *h);
21static int buffer_free(BIO *data);
22static long buffer_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
23#define DEFAULT_BUFFER_SIZE     4096
24
25static const BIO_METHOD methods_buffer = {
26    BIO_TYPE_BUFFER,
27    "buffer",
28    /* TODO: Convert to new style write function */
29    bwrite_conv,
30    buffer_write,
31    /* TODO: Convert to new style read function */
32    bread_conv,
33    buffer_read,
34    buffer_puts,
35    buffer_gets,
36    buffer_ctrl,
37    buffer_new,
38    buffer_free,
39    buffer_callback_ctrl,
40};
41
42const BIO_METHOD *BIO_f_buffer(void)
43{
44    return &methods_buffer;
45}
46
47static int buffer_new(BIO *bi)
48{
49    BIO_F_BUFFER_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));
50
51    if (ctx == NULL)
52        return 0;
53    ctx->ibuf_size = DEFAULT_BUFFER_SIZE;
54    ctx->ibuf = OPENSSL_malloc(DEFAULT_BUFFER_SIZE);
55    if (ctx->ibuf == NULL) {
56        OPENSSL_free(ctx);
57        return 0;
58    }
59    ctx->obuf_size = DEFAULT_BUFFER_SIZE;
60    ctx->obuf = OPENSSL_malloc(DEFAULT_BUFFER_SIZE);
61    if (ctx->obuf == NULL) {
62        OPENSSL_free(ctx->ibuf);
63        OPENSSL_free(ctx);
64        return 0;
65    }
66
67    bi->init = 1;
68    bi->ptr = (char *)ctx;
69    bi->flags = 0;
70    return 1;
71}
72
73static int buffer_free(BIO *a)
74{
75    BIO_F_BUFFER_CTX *b;
76
77    if (a == NULL)
78        return 0;
79    b = (BIO_F_BUFFER_CTX *)a->ptr;
80    OPENSSL_free(b->ibuf);
81    OPENSSL_free(b->obuf);
82    OPENSSL_free(a->ptr);
83    a->ptr = NULL;
84    a->init = 0;
85    a->flags = 0;
86    return 1;
87}
88
89static int buffer_read(BIO *b, char *out, int outl)
90{
91    int i, num = 0;
92    BIO_F_BUFFER_CTX *ctx;
93
94    if (out == NULL)
95        return 0;
96    ctx = (BIO_F_BUFFER_CTX *)b->ptr;
97
98    if ((ctx == NULL) || (b->next_bio == NULL))
99        return 0;
100    num = 0;
101    BIO_clear_retry_flags(b);
102
103 start:
104    i = ctx->ibuf_len;
105    /* If there is stuff left over, grab it */
106    if (i != 0) {
107        if (i > outl)
108            i = outl;
109        memcpy(out, &(ctx->ibuf[ctx->ibuf_off]), i);
110        ctx->ibuf_off += i;
111        ctx->ibuf_len -= i;
112        num += i;
113        if (outl == i)
114            return num;
115        outl -= i;
116        out += i;
117    }
118
119    /*
120     * We may have done a partial read. try to do more. We have nothing in
121     * the buffer. If we get an error and have read some data, just return it
122     * and let them retry to get the error again. copy direct to parent
123     * address space
124     */
125    if (outl > ctx->ibuf_size) {
126        for (;;) {
127            i = BIO_read(b->next_bio, out, outl);
128            if (i <= 0) {
129                BIO_copy_next_retry(b);
130                if (i < 0)
131                    return ((num > 0) ? num : i);
132                if (i == 0)
133                    return num;
134            }
135            num += i;
136            if (outl == i)
137                return num;
138            out += i;
139            outl -= i;
140        }
141    }
142    /* else */
143
144    /* we are going to be doing some buffering */
145    i = BIO_read(b->next_bio, ctx->ibuf, ctx->ibuf_size);
146    if (i <= 0) {
147        BIO_copy_next_retry(b);
148        if (i < 0)
149            return ((num > 0) ? num : i);
150        if (i == 0)
151            return num;
152    }
153    ctx->ibuf_off = 0;
154    ctx->ibuf_len = i;
155
156    /* Lets re-read using ourselves :-) */
157    goto start;
158}
159
160static int buffer_write(BIO *b, const char *in, int inl)
161{
162    int i, num = 0;
163    BIO_F_BUFFER_CTX *ctx;
164
165    if ((in == NULL) || (inl <= 0))
166        return 0;
167    ctx = (BIO_F_BUFFER_CTX *)b->ptr;
168    if ((ctx == NULL) || (b->next_bio == NULL))
169        return 0;
170
171    BIO_clear_retry_flags(b);
172 start:
173    i = ctx->obuf_size - (ctx->obuf_len + ctx->obuf_off);
174    /* add to buffer and return */
175    if (i >= inl) {
176        memcpy(&(ctx->obuf[ctx->obuf_off + ctx->obuf_len]), in, inl);
177        ctx->obuf_len += inl;
178        return (num + inl);
179    }
180    /* else */
181    /* stuff already in buffer, so add to it first, then flush */
182    if (ctx->obuf_len != 0) {
183        if (i > 0) {            /* lets fill it up if we can */
184            memcpy(&(ctx->obuf[ctx->obuf_off + ctx->obuf_len]), in, i);
185            in += i;
186            inl -= i;
187            num += i;
188            ctx->obuf_len += i;
189        }
190        /* we now have a full buffer needing flushing */
191        for (;;) {
192            i = BIO_write(b->next_bio, &(ctx->obuf[ctx->obuf_off]),
193                          ctx->obuf_len);
194            if (i <= 0) {
195                BIO_copy_next_retry(b);
196
197                if (i < 0)
198                    return ((num > 0) ? num : i);
199                if (i == 0)
200                    return num;
201            }
202            ctx->obuf_off += i;
203            ctx->obuf_len -= i;
204            if (ctx->obuf_len == 0)
205                break;
206        }
207    }
208    /*
209     * we only get here if the buffer has been flushed and we still have
210     * stuff to write
211     */
212    ctx->obuf_off = 0;
213
214    /* we now have inl bytes to write */
215    while (inl >= ctx->obuf_size) {
216        i = BIO_write(b->next_bio, in, inl);
217        if (i <= 0) {
218            BIO_copy_next_retry(b);
219            if (i < 0)
220                return ((num > 0) ? num : i);
221            if (i == 0)
222                return num;
223        }
224        num += i;
225        in += i;
226        inl -= i;
227        if (inl == 0)
228            return num;
229    }
230
231    /*
232     * copy the rest into the buffer since we have only a small amount left
233     */
234    goto start;
235}
236
237static long buffer_ctrl(BIO *b, int cmd, long num, void *ptr)
238{
239    BIO *dbio;
240    BIO_F_BUFFER_CTX *ctx;
241    long ret = 1;
242    char *p1, *p2;
243    int r, i, *ip;
244    int ibs, obs;
245
246    ctx = (BIO_F_BUFFER_CTX *)b->ptr;
247
248    switch (cmd) {
249    case BIO_CTRL_RESET:
250        ctx->ibuf_off = 0;
251        ctx->ibuf_len = 0;
252        ctx->obuf_off = 0;
253        ctx->obuf_len = 0;
254        if (b->next_bio == NULL)
255            return 0;
256        ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
257        break;
258    case BIO_CTRL_EOF:
259        if (ctx->ibuf_len > 0)
260            return 0;
261        ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
262        break;
263    case BIO_CTRL_INFO:
264        ret = (long)ctx->obuf_len;
265        break;
266    case BIO_C_GET_BUFF_NUM_LINES:
267        ret = 0;
268        p1 = ctx->ibuf;
269        for (i = 0; i < ctx->ibuf_len; i++) {
270            if (p1[ctx->ibuf_off + i] == '\n')
271                ret++;
272        }
273        break;
274    case BIO_CTRL_WPENDING:
275        ret = (long)ctx->obuf_len;
276        if (ret == 0) {
277            if (b->next_bio == NULL)
278                return 0;
279            ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
280        }
281        break;
282    case BIO_CTRL_PENDING:
283        ret = (long)ctx->ibuf_len;
284        if (ret == 0) {
285            if (b->next_bio == NULL)
286                return 0;
287            ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
288        }
289        break;
290    case BIO_C_SET_BUFF_READ_DATA:
291        if (num > ctx->ibuf_size) {
292            p1 = OPENSSL_malloc((int)num);
293            if (p1 == NULL)
294                goto malloc_error;
295            OPENSSL_free(ctx->ibuf);
296            ctx->ibuf = p1;
297        }
298        ctx->ibuf_off = 0;
299        ctx->ibuf_len = (int)num;
300        memcpy(ctx->ibuf, ptr, (int)num);
301        ret = 1;
302        break;
303    case BIO_C_SET_BUFF_SIZE:
304        if (ptr != NULL) {
305            ip = (int *)ptr;
306            if (*ip == 0) {
307                ibs = (int)num;
308                obs = ctx->obuf_size;
309            } else {            /* if (*ip == 1) */
310
311                ibs = ctx->ibuf_size;
312                obs = (int)num;
313            }
314        } else {
315            ibs = (int)num;
316            obs = (int)num;
317        }
318        p1 = ctx->ibuf;
319        p2 = ctx->obuf;
320        if ((ibs > DEFAULT_BUFFER_SIZE) && (ibs != ctx->ibuf_size)) {
321            p1 = OPENSSL_malloc((int)num);
322            if (p1 == NULL)
323                goto malloc_error;
324        }
325        if ((obs > DEFAULT_BUFFER_SIZE) && (obs != ctx->obuf_size)) {
326            p2 = OPENSSL_malloc((int)num);
327            if (p2 == NULL) {
328                if (p1 != ctx->ibuf)
329                    OPENSSL_free(p1);
330                goto malloc_error;
331            }
332        }
333        if (ctx->ibuf != p1) {
334            OPENSSL_free(ctx->ibuf);
335            ctx->ibuf = p1;
336            ctx->ibuf_off = 0;
337            ctx->ibuf_len = 0;
338            ctx->ibuf_size = ibs;
339        }
340        if (ctx->obuf != p2) {
341            OPENSSL_free(ctx->obuf);
342            ctx->obuf = p2;
343            ctx->obuf_off = 0;
344            ctx->obuf_len = 0;
345            ctx->obuf_size = obs;
346        }
347        break;
348    case BIO_C_DO_STATE_MACHINE:
349        if (b->next_bio == NULL)
350            return 0;
351        BIO_clear_retry_flags(b);
352        ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
353        BIO_copy_next_retry(b);
354        break;
355
356    case BIO_CTRL_FLUSH:
357        if (b->next_bio == NULL)
358            return 0;
359        if (ctx->obuf_len <= 0) {
360            ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
361            break;
362        }
363
364        for (;;) {
365            BIO_clear_retry_flags(b);
366            if (ctx->obuf_len > 0) {
367                r = BIO_write(b->next_bio,
368                              &(ctx->obuf[ctx->obuf_off]), ctx->obuf_len);
369                BIO_copy_next_retry(b);
370                if (r <= 0)
371                    return (long)r;
372                ctx->obuf_off += r;
373                ctx->obuf_len -= r;
374            } else {
375                ctx->obuf_len = 0;
376                ctx->obuf_off = 0;
377                break;
378            }
379        }
380        ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
381        break;
382    case BIO_CTRL_DUP:
383        dbio = (BIO *)ptr;
384        if (!BIO_set_read_buffer_size(dbio, ctx->ibuf_size) ||
385            !BIO_set_write_buffer_size(dbio, ctx->obuf_size))
386            ret = 0;
387        break;
388    case BIO_CTRL_PEEK:
389        /* Ensure there's stuff in the input buffer */
390        {
391            char fake_buf[1];
392            (void)buffer_read(b, fake_buf, 0);
393        }
394        if (num > ctx->ibuf_len)
395            num = ctx->ibuf_len;
396        memcpy(ptr, &(ctx->ibuf[ctx->ibuf_off]), num);
397        ret = num;
398        break;
399    default:
400        if (b->next_bio == NULL)
401            return 0;
402        ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
403        break;
404    }
405    return ret;
406 malloc_error:
407    BIOerr(BIO_F_BUFFER_CTRL, ERR_R_MALLOC_FAILURE);
408    return 0;
409}
410
411static long buffer_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
412{
413    long ret = 1;
414
415    if (b->next_bio == NULL)
416        return 0;
417    switch (cmd) {
418    default:
419        ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
420        break;
421    }
422    return ret;
423}
424
425static int buffer_gets(BIO *b, char *buf, int size)
426{
427    BIO_F_BUFFER_CTX *ctx;
428    int num = 0, i, flag;
429    char *p;
430
431    ctx = (BIO_F_BUFFER_CTX *)b->ptr;
432    size--;                     /* reserve space for a '\0' */
433    BIO_clear_retry_flags(b);
434
435    for (;;) {
436        if (ctx->ibuf_len > 0) {
437            p = &(ctx->ibuf[ctx->ibuf_off]);
438            flag = 0;
439            for (i = 0; (i < ctx->ibuf_len) && (i < size); i++) {
440                *(buf++) = p[i];
441                if (p[i] == '\n') {
442                    flag = 1;
443                    i++;
444                    break;
445                }
446            }
447            num += i;
448            size -= i;
449            ctx->ibuf_len -= i;
450            ctx->ibuf_off += i;
451            if (flag || size == 0) {
452                *buf = '\0';
453                return num;
454            }
455        } else {                /* read another chunk */
456
457            i = BIO_read(b->next_bio, ctx->ibuf, ctx->ibuf_size);
458            if (i <= 0) {
459                BIO_copy_next_retry(b);
460                *buf = '\0';
461                if (i < 0)
462                    return ((num > 0) ? num : i);
463                if (i == 0)
464                    return num;
465            }
466            ctx->ibuf_len = i;
467            ctx->ibuf_off = 0;
468        }
469    }
470}
471
472static int buffer_puts(BIO *b, const char *str)
473{
474    return buffer_write(b, str, strlen(str));
475}
476