summaryrefslogtreecommitdiff
path: root/drivers/builtin_openssl/crypto/comp/c_zlib.c
blob: 8adf35f3fc9cfcdc52b7651358a51b8d81983f19 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/objects.h>
#include <openssl/comp.h>
#include <openssl/err.h>

COMP_METHOD *COMP_zlib(void );

static COMP_METHOD zlib_method_nozlib={
	NID_undef,
	"(undef)",
	NULL,
	NULL,
	NULL,
	NULL,
	NULL,
	NULL,
	};

#ifndef ZLIB
#undef ZLIB_SHARED
#else

#include <zlib.h>

static int zlib_stateful_init(COMP_CTX *ctx);
static void zlib_stateful_finish(COMP_CTX *ctx);
static int zlib_stateful_compress_block(COMP_CTX *ctx, unsigned char *out,
	unsigned int olen, unsigned char *in, unsigned int ilen);
static int zlib_stateful_expand_block(COMP_CTX *ctx, unsigned char *out,
	unsigned int olen, unsigned char *in, unsigned int ilen);


/* memory allocations functions for zlib intialization */
static void* zlib_zalloc(void* opaque, unsigned int no, unsigned int size)
{
	void *p;
	
	p=OPENSSL_malloc(no*size);
	if (p)
		memset(p, 0, no*size);
	return p;
}


static void zlib_zfree(void* opaque, void* address)
{
	OPENSSL_free(address);
}

#if 0
static int zlib_compress_block(COMP_CTX *ctx, unsigned char *out,
	unsigned int olen, unsigned char *in, unsigned int ilen);
static int zlib_expand_block(COMP_CTX *ctx, unsigned char *out,
	unsigned int olen, unsigned char *in, unsigned int ilen);

static int zz_uncompress(Bytef *dest, uLongf *destLen, const Bytef *source,
	uLong sourceLen);

static COMP_METHOD zlib_stateless_method={
	NID_zlib_compression,
	LN_zlib_compression,
	NULL,
	NULL,
	zlib_compress_block,
	zlib_expand_block,
	NULL,
	NULL,
	};
#endif

static COMP_METHOD zlib_stateful_method={
	NID_zlib_compression,
	LN_zlib_compression,
	zlib_stateful_init,
	zlib_stateful_finish,
	zlib_stateful_compress_block,
	zlib_stateful_expand_block,
	NULL,
	NULL,
	};

/* 
 * When OpenSSL is built on Windows, we do not want to require that
 * the ZLIB.DLL be available in order for the OpenSSL DLLs to
 * work.  Therefore, all ZLIB routines are loaded at run time
 * and we do not link to a .LIB file when ZLIB_SHARED is set.
 */
#if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)
# include <windows.h>
#endif /* !(OPENSSL_SYS_WINDOWS || OPENSSL_SYS_WIN32) */

#ifdef ZLIB_SHARED
#include <openssl/dso.h>

/* Function pointers */
typedef int (*compress_ft)(Bytef *dest,uLongf *destLen,
	const Bytef *source, uLong sourceLen);
typedef int (*inflateEnd_ft)(z_streamp strm);
typedef int (*inflate_ft)(z_streamp strm, int flush);
typedef int (*inflateInit__ft)(z_streamp strm,
	const char * version, int stream_size);
typedef int (*deflateEnd_ft)(z_streamp strm);
typedef int (*deflate_ft)(z_streamp strm, int flush);
typedef int (*deflateInit__ft)(z_streamp strm, int level,
	const char * version, int stream_size);
typedef const char * (*zError__ft)(int err);
static compress_ft	p_compress=NULL;
static inflateEnd_ft	p_inflateEnd=NULL;
static inflate_ft	p_inflate=NULL;
static inflateInit__ft	p_inflateInit_=NULL;
static deflateEnd_ft	p_deflateEnd=NULL;
static deflate_ft	p_deflate=NULL;
static deflateInit__ft	p_deflateInit_=NULL;
static zError__ft	p_zError=NULL;

static int zlib_loaded = 0;     /* only attempt to init func pts once */
static DSO *zlib_dso = NULL;

#define compress                p_compress
#define inflateEnd              p_inflateEnd
#define inflate                 p_inflate
#define inflateInit_            p_inflateInit_
#define deflateEnd              p_deflateEnd
#define deflate                 p_deflate
#define deflateInit_            p_deflateInit_
#define zError			p_zError
#endif /* ZLIB_SHARED */

struct zlib_state
	{
	z_stream istream;
	z_stream ostream;
	};

static int zlib_stateful_ex_idx = -1;

static int zlib_stateful_init(COMP_CTX *ctx)
	{
	int err;
	struct zlib_state *state =
		(struct zlib_state *)OPENSSL_malloc(sizeof(struct zlib_state));

	if (state == NULL)
		goto err;

	state->istream.zalloc = zlib_zalloc;
	state->istream.zfree = zlib_zfree;
	state->istream.opaque = Z_NULL;
	state->istream.next_in = Z_NULL;
	state->istream.next_out = Z_NULL;
	state->istream.avail_in = 0;
	state->istream.avail_out = 0;
	err = inflateInit_(&state->istream,
		ZLIB_VERSION, sizeof(z_stream));
	if (err != Z_OK)
		goto err;

	state->ostream.zalloc = zlib_zalloc;
	state->ostream.zfree = zlib_zfree;
	state->ostream.opaque = Z_NULL;
	state->ostream.next_in = Z_NULL;
	state->ostream.next_out = Z_NULL;
	state->ostream.avail_in = 0;
	state->ostream.avail_out = 0;
	err = deflateInit_(&state->ostream,Z_DEFAULT_COMPRESSION,
		ZLIB_VERSION, sizeof(z_stream));
	if (err != Z_OK)
		goto err;

	CRYPTO_new_ex_data(CRYPTO_EX_INDEX_COMP,ctx,&ctx->ex_data);
	CRYPTO_set_ex_data(&ctx->ex_data,zlib_stateful_ex_idx,state);
	return 1;
 err:
	if (state) OPENSSL_free(state);
	return 0;
	}

static void zlib_stateful_finish(COMP_CTX *ctx)
	{
	struct zlib_state *state =
		(struct zlib_state *)CRYPTO_get_ex_data(&ctx->ex_data,
			zlib_stateful_ex_idx);
	inflateEnd(&state->istream);
	deflateEnd(&state->ostream);
	OPENSSL_free(state);
	CRYPTO_free_ex_data(CRYPTO_EX_INDEX_COMP,ctx,&ctx->ex_data);
	}

static int zlib_stateful_compress_block(COMP_CTX *ctx, unsigned char *out,
	unsigned int olen, unsigned char *in, unsigned int ilen)
	{
	int err = Z_OK;
	struct zlib_state *state =
		(struct zlib_state *)CRYPTO_get_ex_data(&ctx->ex_data,
			zlib_stateful_ex_idx);

	if (state == NULL)
		return -1;

	state->ostream.next_in = in;
	state->ostream.avail_in = ilen;
	state->ostream.next_out = out;
	state->ostream.avail_out = olen;
	if (ilen > 0)
		err = deflate(&state->ostream, Z_SYNC_FLUSH);
	if (err != Z_OK)
		return -1;
#ifdef DEBUG_ZLIB
	fprintf(stderr,"compress(%4d)->%4d %s\n",
		ilen,olen - state->ostream.avail_out,
		(ilen != olen - state->ostream.avail_out)?"zlib":"clear");
#endif
	return olen - state->ostream.avail_out;
	}

static int zlib_stateful_expand_block(COMP_CTX *ctx, unsigned char *out,
	unsigned int olen, unsigned char *in, unsigned int ilen)
	{
	int err = Z_OK;

	struct zlib_state *state =
		(struct zlib_state *)CRYPTO_get_ex_data(&ctx->ex_data,
			zlib_stateful_ex_idx);

	if (state == NULL)
		return 0;

	state->istream.next_in = in;
	state->istream.avail_in = ilen;
	state->istream.next_out = out;
	state->istream.avail_out = olen;
	if (ilen > 0)
		err = inflate(&state->istream, Z_SYNC_FLUSH);
	if (err != Z_OK)
		return -1;
#ifdef DEBUG_ZLIB
	fprintf(stderr,"expand(%4d)->%4d %s\n",
		ilen,olen - state->istream.avail_out,
		(ilen != olen - state->istream.avail_out)?"zlib":"clear");
#endif
	return olen - state->istream.avail_out;
	}

#if 0
static int zlib_compress_block(COMP_CTX *ctx, unsigned char *out,
	unsigned int olen, unsigned char *in, unsigned int ilen)
	{
	unsigned long l;
	int i;
	int clear=1;

	if (ilen > 128)
		{
		out[0]=1;
		l=olen-1;
		i=compress(&(out[1]),&l,in,(unsigned long)ilen);
		if (i != Z_OK)
			return(-1);
		if (ilen > l)
			{
			clear=0;
			l++;
			}
		}
	if (clear)
		{
		out[0]=0;
		memcpy(&(out[1]),in,ilen);
		l=ilen+1;
		}
#ifdef DEBUG_ZLIB
	fprintf(stderr,"compress(%4d)->%4d %s\n",
		ilen,(int)l,(clear)?"clear":"zlib");
#endif
	return((int)l);
	}

static int zlib_expand_block(COMP_CTX *ctx, unsigned char *out,
	unsigned int olen, unsigned char *in, unsigned int ilen)
	{
	unsigned long l;
	int i;

	if (in[0])
		{
		l=olen;
		i=zz_uncompress(out,&l,&(in[1]),(unsigned long)ilen-1);
		if (i != Z_OK)
			return(-1);
		}
	else
		{
		memcpy(out,&(in[1]),ilen-1);
		l=ilen-1;
		}
#ifdef DEBUG_ZLIB
        fprintf(stderr,"expand  (%4d)->%4d %s\n",
		ilen,(int)l,in[0]?"zlib":"clear");
#endif
	return((int)l);
	}

static int zz_uncompress (Bytef *dest, uLongf *destLen, const Bytef *source,
	     uLong sourceLen)
{
    z_stream stream;
    int err;

    stream.next_in = (Bytef*)source;
    stream.avail_in = (uInt)sourceLen;
    /* Check for source > 64K on 16-bit machine: */
    if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;

    stream.next_out = dest;
    stream.avail_out = (uInt)*destLen;
    if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;

    stream.zalloc = (alloc_func)0;
    stream.zfree = (free_func)0;

    err = inflateInit_(&stream,
	    ZLIB_VERSION, sizeof(z_stream));
    if (err != Z_OK) return err;

    err = inflate(&stream, Z_FINISH);
    if (err != Z_STREAM_END) {
        inflateEnd(&stream);
        return err;
    }
    *destLen = stream.total_out;

    err = inflateEnd(&stream);
    return err;
}
#endif

#endif

COMP_METHOD *COMP_zlib(void)
	{
	COMP_METHOD *meth = &zlib_method_nozlib;

#ifdef ZLIB_SHARED
	if (!zlib_loaded)
		{
#if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)
		zlib_dso = DSO_load(NULL, "ZLIB1", NULL, 0);
#else
		zlib_dso = DSO_load(NULL, "z", NULL, 0);
#endif
		if (zlib_dso != NULL)
			{
			p_compress
				= (compress_ft) DSO_bind_func(zlib_dso,
					"compress");
			p_inflateEnd
				= (inflateEnd_ft) DSO_bind_func(zlib_dso,
					"inflateEnd");
			p_inflate
				= (inflate_ft) DSO_bind_func(zlib_dso,
					"inflate");
			p_inflateInit_
				= (inflateInit__ft) DSO_bind_func(zlib_dso,
					"inflateInit_");
			p_deflateEnd
				= (deflateEnd_ft) DSO_bind_func(zlib_dso,
					"deflateEnd");
			p_deflate
				= (deflate_ft) DSO_bind_func(zlib_dso,
					"deflate");
			p_deflateInit_
				= (deflateInit__ft) DSO_bind_func(zlib_dso,
					"deflateInit_");
			p_zError
				= (zError__ft) DSO_bind_func(zlib_dso,
					"zError");

			if (p_compress && p_inflateEnd && p_inflate
				&& p_inflateInit_ && p_deflateEnd
				&& p_deflate && p_deflateInit_ && p_zError)
				zlib_loaded++;
			}
		}

#endif
#ifdef ZLIB_SHARED
	if (zlib_loaded)
#endif
#if defined(ZLIB) || defined(ZLIB_SHARED)
		{
		/* init zlib_stateful_ex_idx here so that in a multi-process
		 * application it's enough to intialize openssl before forking
		 * (idx will be inherited in all the children) */
		if (zlib_stateful_ex_idx == -1)
			{
			CRYPTO_w_lock(CRYPTO_LOCK_COMP);
			if (zlib_stateful_ex_idx == -1)
				zlib_stateful_ex_idx =
					CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_COMP,
						0,NULL,NULL,NULL,NULL);
			CRYPTO_w_unlock(CRYPTO_LOCK_COMP);
			if (zlib_stateful_ex_idx == -1)
				goto err;
			}
		
		meth = &zlib_stateful_method;
		}
err:	
#endif

	return(meth);
	}

void COMP_zlib_cleanup(void)
	{
#ifdef ZLIB_SHARED
	if (zlib_dso)
		DSO_free(zlib_dso);
#endif
	}

#ifdef ZLIB

/* Zlib based compression/decompression filter BIO */

typedef struct
	{
	unsigned char *ibuf;	/* Input buffer */
	int ibufsize;		/* Buffer size */
	z_stream zin;		/* Input decompress context */
	unsigned char *obuf;	/* Output buffer */
	int obufsize;		/* Output buffer size */
	unsigned char *optr;	/* Position in output buffer */
	int ocount;		/* Amount of data in output buffer */
	int odone;		/* deflate EOF */
	int comp_level;		/* Compression level to use */
	z_stream zout;		/* Output compression context */
	} BIO_ZLIB_CTX;

#define ZLIB_DEFAULT_BUFSIZE 1024

static int bio_zlib_new(BIO *bi);
static int bio_zlib_free(BIO *bi);
static int bio_zlib_read(BIO *b, char *out, int outl);
static int bio_zlib_write(BIO *b, const char *in, int inl);
static long bio_zlib_ctrl(BIO *b, int cmd, long num, void *ptr);
static long bio_zlib_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp);

static BIO_METHOD bio_meth_zlib = 
	{
	BIO_TYPE_COMP,
	"zlib",
	bio_zlib_write,
	bio_zlib_read,
	NULL,
	NULL,
	bio_zlib_ctrl,
	bio_zlib_new,
	bio_zlib_free,
	bio_zlib_callback_ctrl
	};

BIO_METHOD *BIO_f_zlib(void)
	{
	return &bio_meth_zlib;
	}


static int bio_zlib_new(BIO *bi)
	{
	BIO_ZLIB_CTX *ctx;
#ifdef ZLIB_SHARED
	(void)COMP_zlib();
	if (!zlib_loaded)
		{
		COMPerr(COMP_F_BIO_ZLIB_NEW, COMP_R_ZLIB_NOT_SUPPORTED);
		return 0;
		}
#endif
	ctx = OPENSSL_malloc(sizeof(BIO_ZLIB_CTX));
	if(!ctx)
		{
		COMPerr(COMP_F_BIO_ZLIB_NEW, ERR_R_MALLOC_FAILURE);
		return 0;
		}
	ctx->ibuf = NULL;
	ctx->obuf = NULL;
	ctx->ibufsize = ZLIB_DEFAULT_BUFSIZE;
	ctx->obufsize = ZLIB_DEFAULT_BUFSIZE;
	ctx->zin.zalloc = Z_NULL;
	ctx->zin.zfree = Z_NULL;
	ctx->zin.next_in = NULL;
	ctx->zin.avail_in = 0;
	ctx->zin.next_out = NULL;
	ctx->zin.avail_out = 0;
	ctx->zout.zalloc = Z_NULL;
	ctx->zout.zfree = Z_NULL;
	ctx->zout.next_in = NULL;
	ctx->zout.avail_in = 0;
	ctx->zout.next_out = NULL;
	ctx->zout.avail_out = 0;
	ctx->odone = 0;
	ctx->comp_level = Z_DEFAULT_COMPRESSION;
	bi->init = 1;
	bi->ptr = (char *)ctx;
	bi->flags = 0;
	return 1;
	}

static int bio_zlib_free(BIO *bi)
	{
	BIO_ZLIB_CTX *ctx;
	if(!bi) return 0;
	ctx = (BIO_ZLIB_CTX *)bi->ptr;
	if(ctx->ibuf)
		{
		/* Destroy decompress context */
		inflateEnd(&ctx->zin);
		OPENSSL_free(ctx->ibuf);
		}
	if(ctx->obuf)
		{
		/* Destroy compress context */
		deflateEnd(&ctx->zout);
		OPENSSL_free(ctx->obuf);
		}
	OPENSSL_free(ctx);
	bi->ptr = NULL;
	bi->init = 0;
	bi->flags = 0;
	return 1;
	}

static int bio_zlib_read(BIO *b, char *out, int outl)
	{
	BIO_ZLIB_CTX *ctx;
	int ret;
	z_stream *zin;
	if(!out || !outl) return 0;
	ctx = (BIO_ZLIB_CTX *)b->ptr;
	zin = &ctx->zin;
	BIO_clear_retry_flags(b);
	if(!ctx->ibuf)
		{
		ctx->ibuf = OPENSSL_malloc(ctx->ibufsize);
		if(!ctx->ibuf)
			{
			COMPerr(COMP_F_BIO_ZLIB_READ, ERR_R_MALLOC_FAILURE);
			return 0;
			}
		inflateInit(zin);
		zin->next_in = ctx->ibuf;
		zin->avail_in = 0;
		}

	/* Copy output data directly to supplied buffer */
	zin->next_out = (unsigned char *)out;
	zin->avail_out = (unsigned int)outl;
	for(;;)
		{
		/* Decompress while data available */
		while(zin->avail_in)
			{
			ret = inflate(zin, 0);
			if((ret != Z_OK) && (ret != Z_STREAM_END))
				{
				COMPerr(COMP_F_BIO_ZLIB_READ,
						COMP_R_ZLIB_INFLATE_ERROR);
				ERR_add_error_data(2, "zlib error:",
							zError(ret));
				return 0;
				}
			/* If EOF or we've read everything then return */
			if((ret == Z_STREAM_END) || !zin->avail_out)
				return outl - zin->avail_out;
			}

		/* No data in input buffer try to read some in,
		 * if an error then return the total data read.
		 */
		ret = BIO_read(b->next_bio, ctx->ibuf, ctx->ibufsize);
		if(ret <= 0)
			{
			/* Total data read */
			int tot = outl - zin->avail_out;
			BIO_copy_next_retry(b);
			if(ret < 0) return (tot > 0) ? tot : ret;
			return tot;
			}
		zin->avail_in = ret;
		zin->next_in = ctx->ibuf;
		}
	}

static int bio_zlib_write(BIO *b, const char *in, int inl)
	{
	BIO_ZLIB_CTX *ctx;
	int ret;
	z_stream *zout;
	if(!in || !inl) return 0;
	ctx = (BIO_ZLIB_CTX *)b->ptr;
	if(ctx->odone) return 0;
	zout = &ctx->zout;
	BIO_clear_retry_flags(b);
	if(!ctx->obuf)
		{
		ctx->obuf = OPENSSL_malloc(ctx->obufsize);
		/* Need error here */
		if(!ctx->obuf)
			{
			COMPerr(COMP_F_BIO_ZLIB_WRITE, ERR_R_MALLOC_FAILURE);
			return 0;
			}
		ctx->optr = ctx->obuf;
		ctx->ocount = 0;
		deflateInit(zout, ctx->comp_level);
		zout->next_out = ctx->obuf;
		zout->avail_out = ctx->obufsize;
		}
	/* Obtain input data directly from supplied buffer */
	zout->next_in = (void *)in;
	zout->avail_in = inl;
	for(;;)
		{
		/* If data in output buffer write it first */
		while(ctx->ocount) {
			ret = BIO_write(b->next_bio, ctx->optr, ctx->ocount);
			if(ret <= 0)
				{
				/* Total data written */
				int tot = inl - zout->avail_in;
				BIO_copy_next_retry(b);
				if(ret < 0) return (tot > 0) ? tot : ret;
				return tot;
				}
			ctx->optr += ret;
			ctx->ocount -= ret;
		}

		/* Have we consumed all supplied data? */
		if(!zout->avail_in)
			return inl;

		/* Compress some more */

		/* Reset buffer */
		ctx->optr = ctx->obuf;
		zout->next_out = ctx->obuf;
		zout->avail_out = ctx->obufsize;
		/* Compress some more */
		ret = deflate(zout, 0);
		if(ret != Z_OK)
			{
			COMPerr(COMP_F_BIO_ZLIB_WRITE,
						COMP_R_ZLIB_DEFLATE_ERROR);
			ERR_add_error_data(2, "zlib error:", zError(ret));
			return 0;
			}
		ctx->ocount = ctx->obufsize - zout->avail_out;
		}
	}

static int bio_zlib_flush(BIO *b)
	{
	BIO_ZLIB_CTX *ctx;
	int ret;
	z_stream *zout;
	ctx = (BIO_ZLIB_CTX *)b->ptr;
	/* If no data written or already flush show success */
	if(!ctx->obuf || (ctx->odone && !ctx->ocount)) return 1;
	zout = &ctx->zout;
	BIO_clear_retry_flags(b);
	/* No more input data */
	zout->next_in = NULL;
	zout->avail_in = 0;
	for(;;)
		{
		/* If data in output buffer write it first */
		while(ctx->ocount)
			{
			ret = BIO_write(b->next_bio, ctx->optr, ctx->ocount);
			if(ret <= 0)
				{
				BIO_copy_next_retry(b);
				return ret;
				}
			ctx->optr += ret;
			ctx->ocount -= ret;
			}
		if(ctx->odone) return 1;

		/* Compress some more */

		/* Reset buffer */
		ctx->optr = ctx->obuf;
		zout->next_out = ctx->obuf;
		zout->avail_out = ctx->obufsize;
		/* Compress some more */
		ret = deflate(zout, Z_FINISH);
		if(ret == Z_STREAM_END) ctx->odone = 1;
		else if(ret != Z_OK)
			{
			COMPerr(COMP_F_BIO_ZLIB_FLUSH,
						COMP_R_ZLIB_DEFLATE_ERROR);
			ERR_add_error_data(2, "zlib error:", zError(ret));
			return 0;
			}
		ctx->ocount = ctx->obufsize - zout->avail_out;
		}
	}

static long bio_zlib_ctrl(BIO *b, int cmd, long num, void *ptr)
	{
	BIO_ZLIB_CTX *ctx;
	int ret, *ip;
	int ibs, obs;
	if(!b->next_bio) return 0;
	ctx = (BIO_ZLIB_CTX *)b->ptr;
	switch (cmd)
		{

	case BIO_CTRL_RESET:
		ctx->ocount = 0;
		ctx->odone = 0;
		ret = 1;
		break;

	case BIO_CTRL_FLUSH:
		ret = bio_zlib_flush(b);
		if (ret > 0)
			ret = BIO_flush(b->next_bio);
		break;

	case BIO_C_SET_BUFF_SIZE:
		ibs = -1;
		obs = -1;
		if (ptr != NULL)
			{
			ip = ptr;
			if (*ip == 0)
				ibs = (int) num;
			else 
				obs = (int) num;
			}
		else
			{
			ibs = (int)num;
			obs = ibs;
			}

		if (ibs != -1)
			{
			if (ctx->ibuf)
				{
				OPENSSL_free(ctx->ibuf);
				ctx->ibuf = NULL;
				}
			ctx->ibufsize = ibs;
			}

		if (obs != -1)
			{
			if (ctx->obuf)
				{
				OPENSSL_free(ctx->obuf);
				ctx->obuf = NULL;
				}
			ctx->obufsize = obs;
			}
		ret = 1;
		break;

	case BIO_C_DO_STATE_MACHINE:
		BIO_clear_retry_flags(b);
		ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
		BIO_copy_next_retry(b);
		break;

	default:
		ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
		break;

		}

	return ret;
	}


static long bio_zlib_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
	{
	if(!b->next_bio)
		return 0;
	return
		BIO_callback_ctrl(b->next_bio, cmd, fp);
	}

#endif