crypto/bio/bf_buff.c

   1 /*
   2  * Copyright 1995-2016 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_lcl.h"
  13 #include "internal/cryptlib.h"
  14
  15 static int buffer_write(BIO *h, const char *buf, int num);
  16 static int buffer_read(BIO *h, char *buf, int size);
  17 static int buffer_puts(BIO *h, const char *str);
  18 static int buffer_gets(BIO *h, char *str, int size);
  19 static long buffer_ctrl(BIO *h, int cmd, long arg1, void *arg2);
  20 static int buffer_new(BIO *h);
  21 static int buffer_free(BIO *data);
  22 static long buffer_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
  23 #define DEFAULT_BUFFER_SIZE     4096
  24
  25 static 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
  42 const BIO_METHOD *BIO_f_buffer(void)
  43 {
  44     return &methods_buffer;
  45 }
  46
  47 static 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
  73 static 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
  89 static 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
 160 static 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
 237 static 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
 411 static 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
 425 static 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
 472 static int buffer_puts(BIO *b, const char *str)
 473 {
 474     return buffer_write(b, str, strlen(str));
 475 }