crypto/comp/c_zlib.c

   1 /* ====================================================================
   2  * Copyright (c) 1999-2015 The OpenSSL Project.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  *
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in
  13  *    the documentation and/or other materials provided with the
  14  *    distribution.
  15  *
  16  * 3. All advertising materials mentioning features or use of this
  17  *    software must display the following acknowledgment:
  18  *    "This product includes software developed by the OpenSSL Project
  19  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  20  *
  21  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  22  *    endorse or promote products derived from this software without
  23  *    prior written permission. For written permission, please contact
  24  *    openssl-core@OpenSSL.org.
  25  *
  26  * 5. Products derived from this software may not be called "OpenSSL"
  27  *    nor may "OpenSSL" appear in their names without prior written
  28  *    permission of the OpenSSL Project.
  29  *
  30  * 6. Redistributions of any form whatsoever must retain the following
  31  *    acknowledgment:
  32  *    "This product includes software developed by the OpenSSL Project
  33  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  34  *
  35  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  36  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  37  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  38  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  39  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  40  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  41  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  42  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  44  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  45  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  46  * OF THE POSSIBILITY OF SUCH DAMAGE.
  47  * ====================================================================
  48  *
  49  * This product includes cryptographic software written by Eric Young
  50  * (eay@cryptsoft.com).  This product includes software written by Tim
  51  * Hudson (tjh@cryptsoft.com).
  52  *
  53  */
  54
  55 #include <stdio.h>
  56 #include <stdlib.h>
  57 #include <string.h>
  58 #include <openssl/objects.h>
  59 #include <openssl/comp.h>
  60 #include <openssl/err.h>
  61 #include <internal/cryptlib_int.h>
  62 #include "comp_lcl.h"
  63
  64 COMP_METHOD *COMP_zlib(void);
  65
  66 static COMP_METHOD zlib_method_nozlib = {
  67     NID_undef,
  68     "(undef)",
  69     NULL,
  70     NULL,
  71     NULL,
  72     NULL,
  73 };
  74
  75 #ifndef ZLIB
  76 # undef ZLIB_SHARED
  77 #else
  78
  79 # include <zlib.h>
  80
  81 static int zlib_stateful_init(COMP_CTX *ctx);
  82 static void zlib_stateful_finish(COMP_CTX *ctx);
  83 static int zlib_stateful_compress_block(COMP_CTX *ctx, unsigned char *out,
  84                                         unsigned int olen, unsigned char *in,
  85                                         unsigned int ilen);
  86 static int zlib_stateful_expand_block(COMP_CTX *ctx, unsigned char *out,
  87                                       unsigned int olen, unsigned char *in,
  88                                       unsigned int ilen);
  89
  90 /* memory allocations functions for zlib initialisation */
  91 static void *zlib_zalloc(void *opaque, unsigned int no, unsigned int size)
  92 {
  93     void *p;
  94
  95     p = OPENSSL_zalloc(no * size);
  96     return p;
  97 }
  98
  99 static void zlib_zfree(void *opaque, void *address)
 100 {
 101     OPENSSL_free(address);
 102 }
 103
 104
 105 static COMP_METHOD zlib_stateful_method = {
 106     NID_zlib_compression,
 107     LN_zlib_compression,
 108     zlib_stateful_init,
 109     zlib_stateful_finish,
 110     zlib_stateful_compress_block,
 111     zlib_stateful_expand_block
 112 };
 113
 114 /*
 115  * When OpenSSL is built on Windows, we do not want to require that
 116  * the ZLIB.DLL be available in order for the OpenSSL DLLs to
 117  * work.  Therefore, all ZLIB routines are loaded at run time
 118  * and we do not link to a .LIB file when ZLIB_SHARED is set.
 119  */
 120 # if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)
 121 #  include <windows.h>
 122 # endif                         /* !(OPENSSL_SYS_WINDOWS ||
 123                                  * OPENSSL_SYS_WIN32) */
 124
 125 # ifdef ZLIB_SHARED
 126 #  include <openssl/dso.h>
 127
 128 /* Function pointers */
 129 typedef int (*compress_ft) (Bytef *dest, uLongf * destLen,
 130                             const Bytef *source, uLong sourceLen);
 131 typedef int (*inflateEnd_ft) (z_streamp strm);
 132 typedef int (*inflate_ft) (z_streamp strm, int flush);
 133 typedef int (*inflateInit__ft) (z_streamp strm,
 134                                 const char *version, int stream_size);
 135 typedef int (*deflateEnd_ft) (z_streamp strm);
 136 typedef int (*deflate_ft) (z_streamp strm, int flush);
 137 typedef int (*deflateInit__ft) (z_streamp strm, int level,
 138                                 const char *version, int stream_size);
 139 typedef const char *(*zError__ft) (int err);
 140 static compress_ft p_compress = NULL;
 141 static inflateEnd_ft p_inflateEnd = NULL;
 142 static inflate_ft p_inflate = NULL;
 143 static inflateInit__ft p_inflateInit_ = NULL;
 144 static deflateEnd_ft p_deflateEnd = NULL;
 145 static deflate_ft p_deflate = NULL;
 146 static deflateInit__ft p_deflateInit_ = NULL;
 147 static zError__ft p_zError = NULL;
 148
 149 static int zlib_loaded = 0;     /* only attempt to init func pts once */
 150 static DSO *zlib_dso = NULL;
 151
 152 #  define compress                p_compress
 153 #  define inflateEnd              p_inflateEnd
 154 #  define inflate                 p_inflate
 155 #  define inflateInit_            p_inflateInit_
 156 #  define deflateEnd              p_deflateEnd
 157 #  define deflate                 p_deflate
 158 #  define deflateInit_            p_deflateInit_
 159 #  define zError                  p_zError
 160 # endif                         /* ZLIB_SHARED */
 161
 162 struct zlib_state {
 163     z_stream istream;
 164     z_stream ostream;
 165 };
 166
 167 static int zlib_stateful_init(COMP_CTX *ctx)
 168 {
 169     int err;
 170     struct zlib_state *state = OPENSSL_zalloc(sizeof(*state));
 171
 172     if (state == NULL)
 173         goto err;
 174
 175     state->istream.zalloc = zlib_zalloc;
 176     state->istream.zfree = zlib_zfree;
 177     state->istream.opaque = Z_NULL;
 178     state->istream.next_in = Z_NULL;
 179     state->istream.next_out = Z_NULL;
 180     err = inflateInit_(&state->istream, ZLIB_VERSION, sizeof(z_stream));
 181     if (err != Z_OK)
 182         goto err;
 183
 184     state->ostream.zalloc = zlib_zalloc;
 185     state->ostream.zfree = zlib_zfree;
 186     state->ostream.opaque = Z_NULL;
 187     state->ostream.next_in = Z_NULL;
 188     state->ostream.next_out = Z_NULL;
 189     err = deflateInit_(&state->ostream, Z_DEFAULT_COMPRESSION,
 190                        ZLIB_VERSION, sizeof(z_stream));
 191     if (err != Z_OK)
 192         goto err;
 193
 194     ctx->data = state;
 195     return 1;
 196  err:
 197     OPENSSL_free(state);
 198     return 0;
 199 }
 200
 201 static void zlib_stateful_finish(COMP_CTX *ctx)
 202 {
 203     struct zlib_state *state = ctx->data;
 204     inflateEnd(&state->istream);
 205     deflateEnd(&state->ostream);
 206     OPENSSL_free(state);
 207 }
 208
 209 static int zlib_stateful_compress_block(COMP_CTX *ctx, unsigned char *out,
 210                                         unsigned int olen, unsigned char *in,
 211                                         unsigned int ilen)
 212 {
 213     int err = Z_OK;
 214     struct zlib_state *state = ctx->data;
 215
 216     if (state == NULL)
 217         return -1;
 218
 219     state->ostream.next_in = in;
 220     state->ostream.avail_in = ilen;
 221     state->ostream.next_out = out;
 222     state->ostream.avail_out = olen;
 223     if (ilen > 0)
 224         err = deflate(&state->ostream, Z_SYNC_FLUSH);
 225     if (err != Z_OK)
 226         return -1;
 227 # ifdef DEBUG_ZLIB
 228     fprintf(stderr, "compress(%4d)->%4d %s\n",
 229             ilen, olen - state->ostream.avail_out,
 230             (ilen != olen - state->ostream.avail_out) ? "zlib" : "clear");
 231 # endif
 232     return olen - state->ostream.avail_out;
 233 }
 234
 235 static int zlib_stateful_expand_block(COMP_CTX *ctx, unsigned char *out,
 236                                       unsigned int olen, unsigned char *in,
 237                                       unsigned int ilen)
 238 {
 239     int err = Z_OK;
 240     struct zlib_state *state = ctx->data;
 241
 242     if (state == NULL)
 243         return 0;
 244
 245     state->istream.next_in = in;
 246     state->istream.avail_in = ilen;
 247     state->istream.next_out = out;
 248     state->istream.avail_out = olen;
 249     if (ilen > 0)
 250         err = inflate(&state->istream, Z_SYNC_FLUSH);
 251     if (err != Z_OK)
 252         return -1;
 253 # ifdef DEBUG_ZLIB
 254     fprintf(stderr, "expand(%4d)->%4d %s\n",
 255             ilen, olen - state->istream.avail_out,
 256             (ilen != olen - state->istream.avail_out) ? "zlib" : "clear");
 257 # endif
 258     return olen - state->istream.avail_out;
 259 }
 260
 261 #endif
 262
 263 COMP_METHOD *COMP_zlib(void)
 264 {
 265     COMP_METHOD *meth = &zlib_method_nozlib;
 266
 267 #ifdef ZLIB_SHARED
 268     if (!zlib_loaded) {
 269 # if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)
 270         zlib_dso = DSO_load(NULL, "ZLIB1", NULL, 0);
 271 # else
 272         zlib_dso = DSO_load(NULL, "z", NULL, 0);
 273 # endif
 274         if (zlib_dso != NULL) {
 275             p_compress = (compress_ft) DSO_bind_func(zlib_dso, "compress");
 276             p_inflateEnd
 277                 = (inflateEnd_ft) DSO_bind_func(zlib_dso, "inflateEnd");
 278             p_inflate = (inflate_ft) DSO_bind_func(zlib_dso, "inflate");
 279             p_inflateInit_
 280                 = (inflateInit__ft) DSO_bind_func(zlib_dso, "inflateInit_");
 281             p_deflateEnd
 282                 = (deflateEnd_ft) DSO_bind_func(zlib_dso, "deflateEnd");
 283             p_deflate = (deflate_ft) DSO_bind_func(zlib_dso, "deflate");
 284             p_deflateInit_
 285                 = (deflateInit__ft) DSO_bind_func(zlib_dso, "deflateInit_");
 286             p_zError = (zError__ft) DSO_bind_func(zlib_dso, "zError");
 287
 288             if (p_compress && p_inflateEnd && p_inflate
 289                 && p_inflateInit_ && p_deflateEnd
 290                 && p_deflate && p_deflateInit_ && p_zError)
 291                 zlib_loaded++;
 292
 293             if (!OPENSSL_init_crypto(OPENSSL_INIT_ZLIB, NULL)) {
 294                 COMP_zlib_cleanup();
 295                 return meth;
 296             }
 297             if (zlib_loaded)
 298                 meth = &zlib_stateful_method;
 299         }
 300     }
 301 #endif
 302 #if defined(ZLIB)
 303     meth = &zlib_stateful_method;
 304 #endif
 305
 306     return (meth);
 307 }
 308
 309 void COMP_zlib_cleanup(void)
 310 {
 311 #ifdef ZLIB_SHARED
 312     if (zlib_dso != NULL)
 313         DSO_free(zlib_dso);
 314     zlib_dso = NULL;
 315 #endif
 316 }
 317
 318 #ifdef ZLIB
 319
 320 /* Zlib based compression/decompression filter BIO */
 321
 322 typedef struct {
 323     unsigned char *ibuf;        /* Input buffer */
 324     int ibufsize;               /* Buffer size */
 325     z_stream zin;               /* Input decompress context */
 326     unsigned char *obuf;        /* Output buffer */
 327     int obufsize;               /* Output buffer size */
 328     unsigned char *optr;        /* Position in output buffer */
 329     int ocount;                 /* Amount of data in output buffer */
 330     int odone;                  /* deflate EOF */
 331     int comp_level;             /* Compression level to use */
 332     z_stream zout;              /* Output compression context */
 333 } BIO_ZLIB_CTX;
 334
 335 # define ZLIB_DEFAULT_BUFSIZE 1024
 336
 337 static int bio_zlib_new(BIO *bi);
 338 static int bio_zlib_free(BIO *bi);
 339 static int bio_zlib_read(BIO *b, char *out, int outl);
 340 static int bio_zlib_write(BIO *b, const char *in, int inl);
 341 static long bio_zlib_ctrl(BIO *b, int cmd, long num, void *ptr);
 342 static long bio_zlib_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp);
 343
 344 static BIO_METHOD bio_meth_zlib = {
 345     BIO_TYPE_COMP,
 346     "zlib",
 347     bio_zlib_write,
 348     bio_zlib_read,
 349     NULL,
 350     NULL,
 351     bio_zlib_ctrl,
 352     bio_zlib_new,
 353     bio_zlib_free,
 354     bio_zlib_callback_ctrl
 355 };
 356
 357 BIO_METHOD *BIO_f_zlib(void)
 358 {
 359     return &bio_meth_zlib;
 360 }
 361
 362 static int bio_zlib_new(BIO *bi)
 363 {
 364     BIO_ZLIB_CTX *ctx;
 365 # ifdef ZLIB_SHARED
 366     (void)COMP_zlib();
 367     if (!zlib_loaded) {
 368         COMPerr(COMP_F_BIO_ZLIB_NEW, COMP_R_ZLIB_NOT_SUPPORTED);
 369         return 0;
 370     }
 371 # endif
 372     ctx = OPENSSL_zalloc(sizeof(*ctx));
 373     if (ctx == NULL) {
 374         COMPerr(COMP_F_BIO_ZLIB_NEW, ERR_R_MALLOC_FAILURE);
 375         return 0;
 376     }
 377     ctx->ibufsize = ZLIB_DEFAULT_BUFSIZE;
 378     ctx->obufsize = ZLIB_DEFAULT_BUFSIZE;
 379     ctx->zin.zalloc = Z_NULL;
 380     ctx->zin.zfree = Z_NULL;
 381     ctx->zout.zalloc = Z_NULL;
 382     ctx->zout.zfree = Z_NULL;
 383     ctx->comp_level = Z_DEFAULT_COMPRESSION;
 384     bi->init = 1;
 385     bi->ptr = (char *)ctx;
 386     bi->flags = 0;
 387     return 1;
 388 }
 389
 390 static int bio_zlib_free(BIO *bi)
 391 {
 392     BIO_ZLIB_CTX *ctx;
 393     if (!bi)
 394         return 0;
 395     ctx = (BIO_ZLIB_CTX *) bi->ptr;
 396     if (ctx->ibuf) {
 397         /* Destroy decompress context */
 398         inflateEnd(&ctx->zin);
 399         OPENSSL_free(ctx->ibuf);
 400     }
 401     if (ctx->obuf) {
 402         /* Destroy compress context */
 403         deflateEnd(&ctx->zout);
 404         OPENSSL_free(ctx->obuf);
 405     }
 406     OPENSSL_free(ctx);
 407     bi->ptr = NULL;
 408     bi->init = 0;
 409     bi->flags = 0;
 410     return 1;
 411 }
 412
 413 static int bio_zlib_read(BIO *b, char *out, int outl)
 414 {
 415     BIO_ZLIB_CTX *ctx;
 416     int ret;
 417     z_stream *zin;
 418     if (!out || !outl)
 419         return 0;
 420     ctx = (BIO_ZLIB_CTX *) b->ptr;
 421     zin = &ctx->zin;
 422     BIO_clear_retry_flags(b);
 423     if (!ctx->ibuf) {
 424         ctx->ibuf = OPENSSL_malloc(ctx->ibufsize);
 425         if (ctx->ibuf == NULL) {
 426             COMPerr(COMP_F_BIO_ZLIB_READ, ERR_R_MALLOC_FAILURE);
 427             return 0;
 428         }
 429         inflateInit(zin);
 430         zin->next_in = ctx->ibuf;
 431         zin->avail_in = 0;
 432     }
 433
 434     /* Copy output data directly to supplied buffer */
 435     zin->next_out = (unsigned char *)out;
 436     zin->avail_out = (unsigned int)outl;
 437     for (;;) {
 438         /* Decompress while data available */
 439         while (zin->avail_in) {
 440             ret = inflate(zin, 0);
 441             if ((ret != Z_OK) && (ret != Z_STREAM_END)) {
 442                 COMPerr(COMP_F_BIO_ZLIB_READ, COMP_R_ZLIB_INFLATE_ERROR);
 443                 ERR_add_error_data(2, "zlib error:", zError(ret));
 444                 return 0;
 445             }
 446             /* If EOF or we've read everything then return */
 447             if ((ret == Z_STREAM_END) || !zin->avail_out)
 448                 return outl - zin->avail_out;
 449         }
 450
 451         /*
 452          * No data in input buffer try to read some in, if an error then
 453          * return the total data read.
 454          */
 455         ret = BIO_read(b->next_bio, ctx->ibuf, ctx->ibufsize);
 456         if (ret <= 0) {
 457             /* Total data read */
 458             int tot = outl - zin->avail_out;
 459             BIO_copy_next_retry(b);
 460             if (ret < 0)
 461                 return (tot > 0) ? tot : ret;
 462             return tot;
 463         }
 464         zin->avail_in = ret;
 465         zin->next_in = ctx->ibuf;
 466     }
 467 }
 468
 469 static int bio_zlib_write(BIO *b, const char *in, int inl)
 470 {
 471     BIO_ZLIB_CTX *ctx;
 472     int ret;
 473     z_stream *zout;
 474     if (!in || !inl)
 475         return 0;
 476     ctx = (BIO_ZLIB_CTX *) b->ptr;
 477     if (ctx->odone)
 478         return 0;
 479     zout = &ctx->zout;
 480     BIO_clear_retry_flags(b);
 481     if (!ctx->obuf) {
 482         ctx->obuf = OPENSSL_malloc(ctx->obufsize);
 483         /* Need error here */
 484         if (ctx->obuf == NULL) {
 485             COMPerr(COMP_F_BIO_ZLIB_WRITE, ERR_R_MALLOC_FAILURE);
 486             return 0;
 487         }
 488         ctx->optr = ctx->obuf;
 489         ctx->ocount = 0;
 490         deflateInit(zout, ctx->comp_level);
 491         zout->next_out = ctx->obuf;
 492         zout->avail_out = ctx->obufsize;
 493     }
 494     /* Obtain input data directly from supplied buffer */
 495     zout->next_in = (void *)in;
 496     zout->avail_in = inl;
 497     for (;;) {
 498         /* If data in output buffer write it first */
 499         while (ctx->ocount) {
 500             ret = BIO_write(b->next_bio, ctx->optr, ctx->ocount);
 501             if (ret <= 0) {
 502                 /* Total data written */
 503                 int tot = inl - zout->avail_in;
 504                 BIO_copy_next_retry(b);
 505                 if (ret < 0)
 506                     return (tot > 0) ? tot : ret;
 507                 return tot;
 508             }
 509             ctx->optr += ret;
 510             ctx->ocount -= ret;
 511         }
 512
 513         /* Have we consumed all supplied data? */
 514         if (!zout->avail_in)
 515             return inl;
 516
 517         /* Compress some more */
 518
 519         /* Reset buffer */
 520         ctx->optr = ctx->obuf;
 521         zout->next_out = ctx->obuf;
 522         zout->avail_out = ctx->obufsize;
 523         /* Compress some more */
 524         ret = deflate(zout, 0);
 525         if (ret != Z_OK) {
 526             COMPerr(COMP_F_BIO_ZLIB_WRITE, COMP_R_ZLIB_DEFLATE_ERROR);
 527             ERR_add_error_data(2, "zlib error:", zError(ret));
 528             return 0;
 529         }
 530         ctx->ocount = ctx->obufsize - zout->avail_out;
 531     }
 532 }
 533
 534 static int bio_zlib_flush(BIO *b)
 535 {
 536     BIO_ZLIB_CTX *ctx;
 537     int ret;
 538     z_stream *zout;
 539     ctx = (BIO_ZLIB_CTX *) b->ptr;
 540     /* If no data written or already flush show success */
 541     if (!ctx->obuf || (ctx->odone && !ctx->ocount))
 542         return 1;
 543     zout = &ctx->zout;
 544     BIO_clear_retry_flags(b);
 545     /* No more input data */
 546     zout->next_in = NULL;
 547     zout->avail_in = 0;
 548     for (;;) {
 549         /* If data in output buffer write it first */
 550         while (ctx->ocount) {
 551             ret = BIO_write(b->next_bio, ctx->optr, ctx->ocount);
 552             if (ret <= 0) {
 553                 BIO_copy_next_retry(b);
 554                 return ret;
 555             }
 556             ctx->optr += ret;
 557             ctx->ocount -= ret;
 558         }
 559         if (ctx->odone)
 560             return 1;
 561
 562         /* Compress some more */
 563
 564         /* Reset buffer */
 565         ctx->optr = ctx->obuf;
 566         zout->next_out = ctx->obuf;
 567         zout->avail_out = ctx->obufsize;
 568         /* Compress some more */
 569         ret = deflate(zout, Z_FINISH);
 570         if (ret == Z_STREAM_END)
 571             ctx->odone = 1;
 572         else if (ret != Z_OK) {
 573             COMPerr(COMP_F_BIO_ZLIB_FLUSH, COMP_R_ZLIB_DEFLATE_ERROR);
 574             ERR_add_error_data(2, "zlib error:", zError(ret));
 575             return 0;
 576         }
 577         ctx->ocount = ctx->obufsize - zout->avail_out;
 578     }
 579 }
 580
 581 static long bio_zlib_ctrl(BIO *b, int cmd, long num, void *ptr)
 582 {
 583     BIO_ZLIB_CTX *ctx;
 584     int ret, *ip;
 585     int ibs, obs;
 586     if (!b->next_bio)
 587         return 0;
 588     ctx = (BIO_ZLIB_CTX *) b->ptr;
 589     switch (cmd) {
 590
 591     case BIO_CTRL_RESET:
 592         ctx->ocount = 0;
 593         ctx->odone = 0;
 594         ret = 1;
 595         break;
 596
 597     case BIO_CTRL_FLUSH:
 598         ret = bio_zlib_flush(b);
 599         if (ret > 0)
 600             ret = BIO_flush(b->next_bio);
 601         break;
 602
 603     case BIO_C_SET_BUFF_SIZE:
 604         ibs = -1;
 605         obs = -1;
 606         if (ptr != NULL) {
 607             ip = ptr;
 608             if (*ip == 0)
 609                 ibs = (int)num;
 610             else
 611                 obs = (int)num;
 612         } else {
 613             ibs = (int)num;
 614             obs = ibs;
 615         }
 616
 617         if (ibs != -1) {
 618             OPENSSL_free(ctx->ibuf);
 619             ctx->ibuf = NULL;
 620             ctx->ibufsize = ibs;
 621         }
 622
 623         if (obs != -1) {
 624             OPENSSL_free(ctx->obuf);
 625             ctx->obuf = NULL;
 626             ctx->obufsize = obs;
 627         }
 628         ret = 1;
 629         break;
 630
 631     case BIO_C_DO_STATE_MACHINE:
 632         BIO_clear_retry_flags(b);
 633         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 634         BIO_copy_next_retry(b);
 635         break;
 636
 637     default:
 638         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 639         break;
 640
 641     }
 642
 643     return ret;
 644 }
 645
 646 static long bio_zlib_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
 647 {
 648     if (!b->next_bio)
 649         return 0;
 650     return BIO_callback_ctrl(b->next_bio, cmd, fp);
 651 }
 652
 653 #endif