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 "comp_lcl.h"
  62
  63 COMP_METHOD *COMP_zlib(void);
  64
  65 static COMP_METHOD zlib_method_nozlib = {
  66     NID_undef,
  67     "(undef)",
  68     NULL,
  69     NULL,
  70     NULL,
  71     NULL,
  72 };
  73
  74 #ifndef ZLIB
  75 # undef ZLIB_SHARED
  76 #else
  77
  78 # include <zlib.h>
  79
  80 static int zlib_stateful_init(COMP_CTX *ctx);
  81 static void zlib_stateful_finish(COMP_CTX *ctx);
  82 static int zlib_stateful_compress_block(COMP_CTX *ctx, unsigned char *out,
  83                                         unsigned int olen, unsigned char *in,
  84                                         unsigned int ilen);
  85 static int zlib_stateful_expand_block(COMP_CTX *ctx, unsigned char *out,
  86                                       unsigned int olen, unsigned char *in,
  87                                       unsigned int ilen);
  88
  89 /* memory allocations functions for zlib intialization */
  90 static void *zlib_zalloc(void *opaque, unsigned int no, unsigned int size)
  91 {
  92     void *p;
  93
  94     p = OPENSSL_zalloc(no * size);
  95     return p;
  96 }
  97
  98 static void zlib_zfree(void *opaque, void *address)
  99 {
 100     OPENSSL_free(address);
 101 }
 102
 103
 104 static COMP_METHOD zlib_stateful_method = {
 105     NID_zlib_compression,
 106     LN_zlib_compression,
 107     zlib_stateful_init,
 108     zlib_stateful_finish,
 109     zlib_stateful_compress_block,
 110     zlib_stateful_expand_block
 111 };
 112
 113 /*
 114  * When OpenSSL is built on Windows, we do not want to require that
 115  * the ZLIB.DLL be available in order for the OpenSSL DLLs to
 116  * work.  Therefore, all ZLIB routines are loaded at run time
 117  * and we do not link to a .LIB file when ZLIB_SHARED is set.
 118  */
 119 # if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)
 120 #  include <windows.h>
 121 # endif                         /* !(OPENSSL_SYS_WINDOWS ||
 122                                  * OPENSSL_SYS_WIN32) */
 123
 124 # ifdef ZLIB_SHARED
 125 #  include <openssl/dso.h>
 126
 127 /* Function pointers */
 128 typedef int (*compress_ft) (Bytef *dest, uLongf * destLen,
 129                             const Bytef *source, uLong sourceLen);
 130 typedef int (*inflateEnd_ft) (z_streamp strm);
 131 typedef int (*inflate_ft) (z_streamp strm, int flush);
 132 typedef int (*inflateInit__ft) (z_streamp strm,
 133                                 const char *version, int stream_size);
 134 typedef int (*deflateEnd_ft) (z_streamp strm);
 135 typedef int (*deflate_ft) (z_streamp strm, int flush);
 136 typedef int (*deflateInit__ft) (z_streamp strm, int level,
 137                                 const char *version, int stream_size);
 138 typedef const char *(*zError__ft) (int err);
 139 static compress_ft p_compress = NULL;
 140 static inflateEnd_ft p_inflateEnd = NULL;
 141 static inflate_ft p_inflate = NULL;
 142 static inflateInit__ft p_inflateInit_ = NULL;
 143 static deflateEnd_ft p_deflateEnd = NULL;
 144 static deflate_ft p_deflate = NULL;
 145 static deflateInit__ft p_deflateInit_ = NULL;
 146 static zError__ft p_zError = NULL;
 147
 148 static int zlib_loaded = 0;     /* only attempt to init func pts once */
 149 static DSO *zlib_dso = NULL;
 150
 151 #  define compress                p_compress
 152 #  define inflateEnd              p_inflateEnd
 153 #  define inflate                 p_inflate
 154 #  define inflateInit_            p_inflateInit_
 155 #  define deflateEnd              p_deflateEnd
 156 #  define deflate                 p_deflate
 157 #  define deflateInit_            p_deflateInit_
 158 #  define zError                  p_zError
 159 # endif                         /* ZLIB_SHARED */
 160
 161 struct zlib_state {
 162     z_stream istream;
 163     z_stream ostream;
 164 };
 165
 166 static int zlib_stateful_init(COMP_CTX *ctx)
 167 {
 168     int err;
 169     struct zlib_state *state = OPENSSL_zalloc(sizeof(*state));
 170
 171     if (state == NULL)
 172         goto err;
 173
 174     state->istream.zalloc = zlib_zalloc;
 175     state->istream.zfree = zlib_zfree;
 176     state->istream.opaque = Z_NULL;
 177     state->istream.next_in = Z_NULL;
 178     state->istream.next_out = Z_NULL;
 179     err = inflateInit_(&state->istream, ZLIB_VERSION, sizeof(z_stream));
 180     if (err != Z_OK)
 181         goto err;
 182
 183     state->ostream.zalloc = zlib_zalloc;
 184     state->ostream.zfree = zlib_zfree;
 185     state->ostream.opaque = Z_NULL;
 186     state->ostream.next_in = Z_NULL;
 187     state->ostream.next_out = Z_NULL;
 188     err = deflateInit_(&state->ostream, Z_DEFAULT_COMPRESSION,
 189                        ZLIB_VERSION, sizeof(z_stream));
 190     if (err != Z_OK)
 191         goto err;
 192
 193     ctx->data = state;
 194     return 1;
 195  err:
 196     OPENSSL_free(state);
 197     return 0;
 198 }
 199
 200 static void zlib_stateful_finish(COMP_CTX *ctx)
 201 {
 202     struct zlib_state *state = ctx->data;
 203     inflateEnd(&state->istream);
 204     deflateEnd(&state->ostream);
 205     OPENSSL_free(state);
 206 }
 207
 208 static int zlib_stateful_compress_block(COMP_CTX *ctx, unsigned char *out,
 209                                         unsigned int olen, unsigned char *in,
 210                                         unsigned int ilen)
 211 {
 212     int err = Z_OK;
 213     struct zlib_state *state = ctx->data;
 214
 215     if (state == NULL)
 216         return -1;
 217
 218     state->ostream.next_in = in;
 219     state->ostream.avail_in = ilen;
 220     state->ostream.next_out = out;
 221     state->ostream.avail_out = olen;
 222     if (ilen > 0)
 223         err = deflate(&state->ostream, Z_SYNC_FLUSH);
 224     if (err != Z_OK)
 225         return -1;
 226 # ifdef DEBUG_ZLIB
 227     fprintf(stderr, "compress(%4d)->%4d %s\n",
 228             ilen, olen - state->ostream.avail_out,
 229             (ilen != olen - state->ostream.avail_out) ? "zlib" : "clear");
 230 # endif
 231     return olen - state->ostream.avail_out;
 232 }
 233
 234 static int zlib_stateful_expand_block(COMP_CTX *ctx, unsigned char *out,
 235                                       unsigned int olen, unsigned char *in,
 236                                       unsigned int ilen)
 237 {
 238     int err = Z_OK;
 239     struct zlib_state *state = ctx->data;
 240
 241     if (state == NULL)
 242         return 0;
 243
 244     state->istream.next_in = in;
 245     state->istream.avail_in = ilen;
 246     state->istream.next_out = out;
 247     state->istream.avail_out = olen;
 248     if (ilen > 0)
 249         err = inflate(&state->istream, Z_SYNC_FLUSH);
 250     if (err != Z_OK)
 251         return -1;
 252 # ifdef DEBUG_ZLIB
 253     fprintf(stderr, "expand(%4d)->%4d %s\n",
 254             ilen, olen - state->istream.avail_out,
 255             (ilen != olen - state->istream.avail_out) ? "zlib" : "clear");
 256 # endif
 257     return olen - state->istream.avail_out;
 258 }
 259
 260 #endif
 261
 262 COMP_METHOD *COMP_zlib(void)
 263 {
 264     COMP_METHOD *meth = &zlib_method_nozlib;
 265
 266 #ifdef ZLIB_SHARED
 267     if (!zlib_loaded) {
 268 # if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)
 269         zlib_dso = DSO_load(NULL, "ZLIB1", NULL, 0);
 270 # else
 271         zlib_dso = DSO_load(NULL, "z", NULL, 0);
 272 # endif
 273         if (zlib_dso != NULL) {
 274             p_compress = (compress_ft) DSO_bind_func(zlib_dso, "compress");
 275             p_inflateEnd
 276                 = (inflateEnd_ft) DSO_bind_func(zlib_dso, "inflateEnd");
 277             p_inflate = (inflate_ft) DSO_bind_func(zlib_dso, "inflate");
 278             p_inflateInit_
 279                 = (inflateInit__ft) DSO_bind_func(zlib_dso, "inflateInit_");
 280             p_deflateEnd
 281                 = (deflateEnd_ft) DSO_bind_func(zlib_dso, "deflateEnd");
 282             p_deflate = (deflate_ft) DSO_bind_func(zlib_dso, "deflate");
 283             p_deflateInit_
 284                 = (deflateInit__ft) DSO_bind_func(zlib_dso, "deflateInit_");
 285             p_zError = (zError__ft) DSO_bind_func(zlib_dso, "zError");
 286
 287             if (p_compress && p_inflateEnd && p_inflate
 288                 && p_inflateInit_ && p_deflateEnd
 289                 && p_deflate && p_deflateInit_ && p_zError)
 290                 zlib_loaded++;
 291             if (zlib_loaded)
 292                 meth = &zlib_stateful_method;
 293         }
 294     }
 295 #endif
 296 #if defined(ZLIB)
 297     meth = &zlib_stateful_method;
 298 #endif
 299
 300     return (meth);
 301 }
 302
 303 void COMP_zlib_cleanup(void)
 304 {
 305 #ifdef ZLIB_SHARED
 306     if (zlib_dso != NULL)
 307         DSO_free(zlib_dso);
 308     zlib_dso = NULL;
 309 #endif
 310 }
 311
 312 #ifdef ZLIB
 313
 314 /* Zlib based compression/decompression filter BIO */
 315
 316 typedef struct {
 317     unsigned char *ibuf;        /* Input buffer */
 318     int ibufsize;               /* Buffer size */
 319     z_stream zin;               /* Input decompress context */
 320     unsigned char *obuf;        /* Output buffer */
 321     int obufsize;               /* Output buffer size */
 322     unsigned char *optr;        /* Position in output buffer */
 323     int ocount;                 /* Amount of data in output buffer */
 324     int odone;                  /* deflate EOF */
 325     int comp_level;             /* Compression level to use */
 326     z_stream zout;              /* Output compression context */
 327 } BIO_ZLIB_CTX;
 328
 329 # define ZLIB_DEFAULT_BUFSIZE 1024
 330
 331 static int bio_zlib_new(BIO *bi);
 332 static int bio_zlib_free(BIO *bi);
 333 static int bio_zlib_read(BIO *b, char *out, int outl);
 334 static int bio_zlib_write(BIO *b, const char *in, int inl);
 335 static long bio_zlib_ctrl(BIO *b, int cmd, long num, void *ptr);
 336 static long bio_zlib_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp);
 337
 338 static BIO_METHOD bio_meth_zlib = {
 339     BIO_TYPE_COMP,
 340     "zlib",
 341     bio_zlib_write,
 342     bio_zlib_read,
 343     NULL,
 344     NULL,
 345     bio_zlib_ctrl,
 346     bio_zlib_new,
 347     bio_zlib_free,
 348     bio_zlib_callback_ctrl
 349 };
 350
 351 BIO_METHOD *BIO_f_zlib(void)
 352 {
 353     return &bio_meth_zlib;
 354 }
 355
 356 static int bio_zlib_new(BIO *bi)
 357 {
 358     BIO_ZLIB_CTX *ctx;
 359 # ifdef ZLIB_SHARED
 360     (void)COMP_zlib();
 361     if (!zlib_loaded) {
 362         COMPerr(COMP_F_BIO_ZLIB_NEW, COMP_R_ZLIB_NOT_SUPPORTED);
 363         return 0;
 364     }
 365 # endif
 366     ctx = OPENSSL_zalloc(sizeof(*ctx));
 367     if (!ctx) {
 368         COMPerr(COMP_F_BIO_ZLIB_NEW, ERR_R_MALLOC_FAILURE);
 369         return 0;
 370     }
 371     ctx->ibufsize = ZLIB_DEFAULT_BUFSIZE;
 372     ctx->obufsize = ZLIB_DEFAULT_BUFSIZE;
 373     ctx->zin.zalloc = Z_NULL;
 374     ctx->zin.zfree = Z_NULL;
 375     ctx->zout.zalloc = Z_NULL;
 376     ctx->zout.zfree = Z_NULL;
 377     ctx->comp_level = Z_DEFAULT_COMPRESSION;
 378     bi->init = 1;
 379     bi->ptr = (char *)ctx;
 380     bi->flags = 0;
 381     return 1;
 382 }
 383
 384 static int bio_zlib_free(BIO *bi)
 385 {
 386     BIO_ZLIB_CTX *ctx;
 387     if (!bi)
 388         return 0;
 389     ctx = (BIO_ZLIB_CTX *) bi->ptr;
 390     if (ctx->ibuf) {
 391         /* Destroy decompress context */
 392         inflateEnd(&ctx->zin);
 393         OPENSSL_free(ctx->ibuf);
 394     }
 395     if (ctx->obuf) {
 396         /* Destroy compress context */
 397         deflateEnd(&ctx->zout);
 398         OPENSSL_free(ctx->obuf);
 399     }
 400     OPENSSL_free(ctx);
 401     bi->ptr = NULL;
 402     bi->init = 0;
 403     bi->flags = 0;
 404     return 1;
 405 }
 406
 407 static int bio_zlib_read(BIO *b, char *out, int outl)
 408 {
 409     BIO_ZLIB_CTX *ctx;
 410     int ret;
 411     z_stream *zin;
 412     if (!out || !outl)
 413         return 0;
 414     ctx = (BIO_ZLIB_CTX *) b->ptr;
 415     zin = &ctx->zin;
 416     BIO_clear_retry_flags(b);
 417     if (!ctx->ibuf) {
 418         ctx->ibuf = OPENSSL_malloc(ctx->ibufsize);
 419         if (!ctx->ibuf) {
 420             COMPerr(COMP_F_BIO_ZLIB_READ, ERR_R_MALLOC_FAILURE);
 421             return 0;
 422         }
 423         inflateInit(zin);
 424         zin->next_in = ctx->ibuf;
 425         zin->avail_in = 0;
 426     }
 427
 428     /* Copy output data directly to supplied buffer */
 429     zin->next_out = (unsigned char *)out;
 430     zin->avail_out = (unsigned int)outl;
 431     for (;;) {
 432         /* Decompress while data available */
 433         while (zin->avail_in) {
 434             ret = inflate(zin, 0);
 435             if ((ret != Z_OK) && (ret != Z_STREAM_END)) {
 436                 COMPerr(COMP_F_BIO_ZLIB_READ, COMP_R_ZLIB_INFLATE_ERROR);
 437                 ERR_add_error_data(2, "zlib error:", zError(ret));
 438                 return 0;
 439             }
 440             /* If EOF or we've read everything then return */
 441             if ((ret == Z_STREAM_END) || !zin->avail_out)
 442                 return outl - zin->avail_out;
 443         }
 444
 445         /*
 446          * No data in input buffer try to read some in, if an error then
 447          * return the total data read.
 448          */
 449         ret = BIO_read(b->next_bio, ctx->ibuf, ctx->ibufsize);
 450         if (ret <= 0) {
 451             /* Total data read */
 452             int tot = outl - zin->avail_out;
 453             BIO_copy_next_retry(b);
 454             if (ret < 0)
 455                 return (tot > 0) ? tot : ret;
 456             return tot;
 457         }
 458         zin->avail_in = ret;
 459         zin->next_in = ctx->ibuf;
 460     }
 461 }
 462
 463 static int bio_zlib_write(BIO *b, const char *in, int inl)
 464 {
 465     BIO_ZLIB_CTX *ctx;
 466     int ret;
 467     z_stream *zout;
 468     if (!in || !inl)
 469         return 0;
 470     ctx = (BIO_ZLIB_CTX *) b->ptr;
 471     if (ctx->odone)
 472         return 0;
 473     zout = &ctx->zout;
 474     BIO_clear_retry_flags(b);
 475     if (!ctx->obuf) {
 476         ctx->obuf = OPENSSL_malloc(ctx->obufsize);
 477         /* Need error here */
 478         if (!ctx->obuf) {
 479             COMPerr(COMP_F_BIO_ZLIB_WRITE, ERR_R_MALLOC_FAILURE);
 480             return 0;
 481         }
 482         ctx->optr = ctx->obuf;
 483         ctx->ocount = 0;
 484         deflateInit(zout, ctx->comp_level);
 485         zout->next_out = ctx->obuf;
 486         zout->avail_out = ctx->obufsize;
 487     }
 488     /* Obtain input data directly from supplied buffer */
 489     zout->next_in = (void *)in;
 490     zout->avail_in = inl;
 491     for (;;) {
 492         /* If data in output buffer write it first */
 493         while (ctx->ocount) {
 494             ret = BIO_write(b->next_bio, ctx->optr, ctx->ocount);
 495             if (ret <= 0) {
 496                 /* Total data written */
 497                 int tot = inl - zout->avail_in;
 498                 BIO_copy_next_retry(b);
 499                 if (ret < 0)
 500                     return (tot > 0) ? tot : ret;
 501                 return tot;
 502             }
 503             ctx->optr += ret;
 504             ctx->ocount -= ret;
 505         }
 506
 507         /* Have we consumed all supplied data? */
 508         if (!zout->avail_in)
 509             return inl;
 510
 511         /* Compress some more */
 512
 513         /* Reset buffer */
 514         ctx->optr = ctx->obuf;
 515         zout->next_out = ctx->obuf;
 516         zout->avail_out = ctx->obufsize;
 517         /* Compress some more */
 518         ret = deflate(zout, 0);
 519         if (ret != Z_OK) {
 520             COMPerr(COMP_F_BIO_ZLIB_WRITE, COMP_R_ZLIB_DEFLATE_ERROR);
 521             ERR_add_error_data(2, "zlib error:", zError(ret));
 522             return 0;
 523         }
 524         ctx->ocount = ctx->obufsize - zout->avail_out;
 525     }
 526 }
 527
 528 static int bio_zlib_flush(BIO *b)
 529 {
 530     BIO_ZLIB_CTX *ctx;
 531     int ret;
 532     z_stream *zout;
 533     ctx = (BIO_ZLIB_CTX *) b->ptr;
 534     /* If no data written or already flush show success */
 535     if (!ctx->obuf || (ctx->odone && !ctx->ocount))
 536         return 1;
 537     zout = &ctx->zout;
 538     BIO_clear_retry_flags(b);
 539     /* No more input data */
 540     zout->next_in = NULL;
 541     zout->avail_in = 0;
 542     for (;;) {
 543         /* If data in output buffer write it first */
 544         while (ctx->ocount) {
 545             ret = BIO_write(b->next_bio, ctx->optr, ctx->ocount);
 546             if (ret <= 0) {
 547                 BIO_copy_next_retry(b);
 548                 return ret;
 549             }
 550             ctx->optr += ret;
 551             ctx->ocount -= ret;
 552         }
 553         if (ctx->odone)
 554             return 1;
 555
 556         /* Compress some more */
 557
 558         /* Reset buffer */
 559         ctx->optr = ctx->obuf;
 560         zout->next_out = ctx->obuf;
 561         zout->avail_out = ctx->obufsize;
 562         /* Compress some more */
 563         ret = deflate(zout, Z_FINISH);
 564         if (ret == Z_STREAM_END)
 565             ctx->odone = 1;
 566         else if (ret != Z_OK) {
 567             COMPerr(COMP_F_BIO_ZLIB_FLUSH, COMP_R_ZLIB_DEFLATE_ERROR);
 568             ERR_add_error_data(2, "zlib error:", zError(ret));
 569             return 0;
 570         }
 571         ctx->ocount = ctx->obufsize - zout->avail_out;
 572     }
 573 }
 574
 575 static long bio_zlib_ctrl(BIO *b, int cmd, long num, void *ptr)
 576 {
 577     BIO_ZLIB_CTX *ctx;
 578     int ret, *ip;
 579     int ibs, obs;
 580     if (!b->next_bio)
 581         return 0;
 582     ctx = (BIO_ZLIB_CTX *) b->ptr;
 583     switch (cmd) {
 584
 585     case BIO_CTRL_RESET:
 586         ctx->ocount = 0;
 587         ctx->odone = 0;
 588         ret = 1;
 589         break;
 590
 591     case BIO_CTRL_FLUSH:
 592         ret = bio_zlib_flush(b);
 593         if (ret > 0)
 594             ret = BIO_flush(b->next_bio);
 595         break;
 596
 597     case BIO_C_SET_BUFF_SIZE:
 598         ibs = -1;
 599         obs = -1;
 600         if (ptr != NULL) {
 601             ip = ptr;
 602             if (*ip == 0)
 603                 ibs = (int)num;
 604             else
 605                 obs = (int)num;
 606         } else {
 607             ibs = (int)num;
 608             obs = ibs;
 609         }
 610
 611         if (ibs != -1) {
 612             OPENSSL_free(ctx->ibuf);
 613             ctx->ibuf = NULL;
 614             ctx->ibufsize = ibs;
 615         }
 616
 617         if (obs != -1) {
 618             OPENSSL_free(ctx->obuf);
 619             ctx->obuf = NULL;
 620             ctx->obufsize = obs;
 621         }
 622         ret = 1;
 623         break;
 624
 625     case BIO_C_DO_STATE_MACHINE:
 626         BIO_clear_retry_flags(b);
 627         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 628         BIO_copy_next_retry(b);
 629         break;
 630
 631     default:
 632         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 633         break;
 634
 635     }
 636
 637     return ret;
 638 }
 639
 640 static long bio_zlib_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
 641 {
 642     if (!b->next_bio)
 643         return 0;
 644     return BIO_callback_ctrl(b->next_bio, cmd, fp);
 645 }
 646
 647 #endif