summaryrefslogtreecommitdiffstats
path: root/contrib/pgcrypto/pgp-encrypt.c
blob: f7467c9b1cb1cd24d5abebdc142527e0d9d10d90 (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
/*
 * pgp-encrypt.c
 *	  OpenPGP encrypt.
 *
 * Copyright (c) 2005 Marko Kreen
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *	  notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *	  notice, this list of conditions and the following disclaimer in the
 *	  documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * contrib/pgcrypto/pgp-encrypt.c
 */

#include "postgres.h"

#include <time.h>

#include "mbuf.h"
#include "pgp.h"
#include "px.h"

#define MDC_DIGEST_LEN 20
#define STREAM_ID 0xE0
#define STREAM_BLOCK_SHIFT	14

static uint8 *
render_newlen(uint8 *h, int len)
{
	if (len <= 191)
	{
		*h++ = len & 255;
	}
	else if (len > 191 && len <= 8383)
	{
		*h++ = ((len - 192) >> 8) + 192;
		*h++ = (len - 192) & 255;
	}
	else
	{
		*h++ = 255;
		*h++ = (len >> 24) & 255;
		*h++ = (len >> 16) & 255;
		*h++ = (len >> 8) & 255;
		*h++ = len & 255;
	}
	return h;
}

static int
write_tag_only(PushFilter *dst, int tag)
{
	uint8		hdr = 0xC0 | tag;

	return pushf_write(dst, &hdr, 1);
}

static int
write_normal_header(PushFilter *dst, int tag, int len)
{
	uint8		hdr[8];
	uint8	   *h = hdr;

	*h++ = 0xC0 | tag;
	h = render_newlen(h, len);
	return pushf_write(dst, hdr, h - hdr);
}


/*
 * MAC writer
 */

static int
mdc_init(PushFilter *dst, void *init_arg, void **priv_p)
{
	int			res;
	PX_MD	   *md;

	res = pgp_load_digest(PGP_DIGEST_SHA1, &md);
	if (res < 0)
		return res;

	*priv_p = md;
	return 0;
}

static int
mdc_write(PushFilter *dst, void *priv, const uint8 *data, int len)
{
	PX_MD	   *md = priv;

	px_md_update(md, data, len);
	return pushf_write(dst, data, len);
}

static int
mdc_flush(PushFilter *dst, void *priv)
{
	int			res;
	uint8		pkt[2 + MDC_DIGEST_LEN];
	PX_MD	   *md = priv;

	/*
	 * create mdc pkt
	 */
	pkt[0] = 0xD3;
	pkt[1] = 0x14;				/* MDC_DIGEST_LEN */
	px_md_update(md, pkt, 2);
	px_md_finish(md, pkt + 2);

	res = pushf_write(dst, pkt, 2 + MDC_DIGEST_LEN);
	px_memset(pkt, 0, 2 + MDC_DIGEST_LEN);
	return res;
}

static void
mdc_free(void *priv)
{
	PX_MD	   *md = priv;

	px_md_free(md);
}

static const PushFilterOps mdc_filter = {
	mdc_init, mdc_write, mdc_flush, mdc_free
};


/*
 * Encrypted pkt writer
 */
#define ENCBUF 8192
struct EncStat
{
	PGP_CFB    *ciph;
	uint8		buf[ENCBUF];
};

static int
encrypt_init(PushFilter *next, void *init_arg, void **priv_p)
{
	struct EncStat *st;
	PGP_Context *ctx = init_arg;
	PGP_CFB    *ciph;
	int			resync = 1;
	int			res;

	/* should we use newer packet format? */
	if (ctx->disable_mdc == 0)
	{
		uint8		ver = 1;

		resync = 0;
		res = pushf_write(next, &ver, 1);
		if (res < 0)
			return res;
	}
	res = pgp_cfb_create(&ciph, ctx->cipher_algo,
						 ctx->sess_key, ctx->sess_key_len, resync, NULL);
	if (res < 0)
		return res;

	st = palloc0(sizeof(*st));
	st->ciph = ciph;

	*priv_p = st;
	return ENCBUF;
}

static int
encrypt_process(PushFilter *next, void *priv, const uint8 *data, int len)
{
	int			res;
	struct EncStat *st = priv;
	int			avail = len;

	while (avail > 0)
	{
		int			tmplen = avail > ENCBUF ? ENCBUF : avail;

		res = pgp_cfb_encrypt(st->ciph, data, tmplen, st->buf);
		if (res < 0)
			return res;

		res = pushf_write(next, st->buf, tmplen);
		if (res < 0)
			return res;

		data += tmplen;
		avail -= tmplen;
	}
	return 0;
}

static void
encrypt_free(void *priv)
{
	struct EncStat *st = priv;

	if (st->ciph)
		pgp_cfb_free(st->ciph);
	px_memset(st, 0, sizeof(*st));
	pfree(st);
}

static const PushFilterOps encrypt_filter = {
	encrypt_init, encrypt_process, NULL, encrypt_free
};

/*
 * Write Streamable pkts
 */

struct PktStreamStat
{
	int			final_done;
	int			pkt_block;
};

static int
pkt_stream_init(PushFilter *next, void *init_arg, void **priv_p)
{
	struct PktStreamStat *st;

	st = palloc(sizeof(*st));
	st->final_done = 0;
	st->pkt_block = 1 << STREAM_BLOCK_SHIFT;
	*priv_p = st;

	return st->pkt_block;
}

static int
pkt_stream_process(PushFilter *next, void *priv, const uint8 *data, int len)
{
	int			res;
	uint8		hdr[8];
	uint8	   *h = hdr;
	struct PktStreamStat *st = priv;

	if (st->final_done)
		return PXE_BUG;

	if (len == st->pkt_block)
		*h++ = STREAM_ID | STREAM_BLOCK_SHIFT;
	else
	{
		h = render_newlen(h, len);
		st->final_done = 1;
	}

	res = pushf_write(next, hdr, h - hdr);
	if (res < 0)
		return res;

	return pushf_write(next, data, len);
}

static int
pkt_stream_flush(PushFilter *next, void *priv)
{
	int			res;
	uint8		hdr[8];
	uint8	   *h = hdr;
	struct PktStreamStat *st = priv;

	/* stream MUST end with normal packet. */
	if (!st->final_done)
	{
		h = render_newlen(h, 0);
		res = pushf_write(next, hdr, h - hdr);
		if (res < 0)
			return res;
		st->final_done = 1;
	}
	return 0;
}

static void
pkt_stream_free(void *priv)
{
	struct PktStreamStat *st = priv;

	px_memset(st, 0, sizeof(*st));
	pfree(st);
}

static const PushFilterOps pkt_stream_filter = {
	pkt_stream_init, pkt_stream_process, pkt_stream_flush, pkt_stream_free
};

int
pgp_create_pkt_writer(PushFilter *dst, int tag, PushFilter **res_p)
{
	int			res;

	res = write_tag_only(dst, tag);
	if (res < 0)
		return res;

	return pushf_create(res_p, &pkt_stream_filter, NULL, dst);
}

/*
 * Text conversion filter
 */

static int
crlf_process(PushFilter *dst, void *priv, const uint8 *data, int len)
{
	const uint8 *data_end = data + len;
	const uint8 *p2,
			   *p1 = data;
	int			line_len;
	static const uint8 crlf[] = {'\r', '\n'};
	int			res = 0;

	while (p1 < data_end)
	{
		p2 = memchr(p1, '\n', data_end - p1);
		if (p2 == NULL)
			p2 = data_end;

		line_len = p2 - p1;

		/* write data */
		res = 0;
		if (line_len > 0)
		{
			res = pushf_write(dst, p1, line_len);
			if (res < 0)
				break;
			p1 += line_len;
		}

		/* write crlf */
		while (p1 < data_end && *p1 == '\n')
		{
			res = pushf_write(dst, crlf, 2);
			if (res < 0)
				break;
			p1++;
		}
	}
	return res;
}

static const PushFilterOps crlf_filter = {
	NULL, crlf_process, NULL, NULL
};

/*
 * Initialize literal data packet
 */
static int
init_litdata_packet(PushFilter **pf_res, PGP_Context *ctx, PushFilter *dst)
{
	int			res;
	int			hdrlen;
	uint8		hdr[6];
	uint32		t;
	PushFilter *pkt;
	int			type;

	/*
	 * Create header
	 */

	if (ctx->text_mode)
		type = ctx->unicode_mode ? 'u' : 't';
	else
		type = 'b';

	/*
	 * Store the creation time into packet. The goal is to have as few known
	 * bytes as possible.
	 */
	t = (uint32) time(NULL);

	hdr[0] = type;
	hdr[1] = 0;
	hdr[2] = (t >> 24) & 255;
	hdr[3] = (t >> 16) & 255;
	hdr[4] = (t >> 8) & 255;
	hdr[5] = t & 255;
	hdrlen = 6;

	res = write_tag_only(dst, PGP_PKT_LITERAL_DATA);
	if (res < 0)
		return res;

	res = pushf_create(&pkt, &pkt_stream_filter, ctx, dst);
	if (res < 0)
		return res;

	res = pushf_write(pkt, hdr, hdrlen);
	if (res < 0)
	{
		pushf_free(pkt);
		return res;
	}

	*pf_res = pkt;
	return 0;
}

/*
 * Initialize compression filter
 */
static int
init_compress(PushFilter **pf_res, PGP_Context *ctx, PushFilter *dst)
{
	int			res;
	uint8		type = ctx->compress_algo;
	PushFilter *pkt;

	res = write_tag_only(dst, PGP_PKT_COMPRESSED_DATA);
	if (res < 0)
		return res;

	res = pushf_create(&pkt, &pkt_stream_filter, ctx, dst);
	if (res < 0)
		return res;

	res = pushf_write(pkt, &type, 1);
	if (res >= 0)
		res = pgp_compress_filter(pf_res, ctx, pkt);

	if (res < 0)
		pushf_free(pkt);

	return res;
}

/*
 * Initialize encdata packet
 */
static int
init_encdata_packet(PushFilter **pf_res, PGP_Context *ctx, PushFilter *dst)
{
	int			res;
	int			tag;

	if (ctx->disable_mdc)
		tag = PGP_PKT_SYMENCRYPTED_DATA;
	else
		tag = PGP_PKT_SYMENCRYPTED_DATA_MDC;

	res = write_tag_only(dst, tag);
	if (res < 0)
		return res;

	return pushf_create(pf_res, &pkt_stream_filter, ctx, dst);
}

/*
 * write prefix
 */
static int
write_prefix(PGP_Context *ctx, PushFilter *dst)
{
	uint8		prefix[PGP_MAX_BLOCK + 2];
	int			res,
				bs;

	bs = pgp_get_cipher_block_size(ctx->cipher_algo);
	if (!pg_strong_random(prefix, bs))
		return PXE_NO_RANDOM;

	prefix[bs + 0] = prefix[bs - 2];
	prefix[bs + 1] = prefix[bs - 1];

	res = pushf_write(dst, prefix, bs + 2);
	px_memset(prefix, 0, bs + 2);
	return res < 0 ? res : 0;
}

/*
 * write symmetrically encrypted session key packet
 */

static int
symencrypt_sesskey(PGP_Context *ctx, uint8 *dst)
{
	int			res;
	PGP_CFB    *cfb;
	uint8		algo = ctx->cipher_algo;

	res = pgp_cfb_create(&cfb, ctx->s2k_cipher_algo,
						 ctx->s2k.key, ctx->s2k.key_len, 0, NULL);
	if (res < 0)
		return res;

	pgp_cfb_encrypt(cfb, &algo, 1, dst);
	pgp_cfb_encrypt(cfb, ctx->sess_key, ctx->sess_key_len, dst + 1);

	pgp_cfb_free(cfb);
	return ctx->sess_key_len + 1;
}

/* 5.3: Symmetric-Key Encrypted Session-Key */
static int
write_symenc_sesskey(PGP_Context *ctx, PushFilter *dst)
{
	uint8		pkt[256];
	int			pktlen;
	int			res;
	uint8	   *p = pkt;

	*p++ = 4;					/* 5.3 - version number  */
	*p++ = ctx->s2k_cipher_algo;

	*p++ = ctx->s2k.mode;
	*p++ = ctx->s2k.digest_algo;
	if (ctx->s2k.mode > 0)
	{
		memcpy(p, ctx->s2k.salt, 8);
		p += 8;
	}
	if (ctx->s2k.mode == 3)
		*p++ = ctx->s2k.iter;

	if (ctx->use_sess_key)
	{
		res = symencrypt_sesskey(ctx, p);
		if (res < 0)
			return res;
		p += res;
	}

	pktlen = p - pkt;
	res = write_normal_header(dst, PGP_PKT_SYMENCRYPTED_SESSKEY, pktlen);
	if (res >= 0)
		res = pushf_write(dst, pkt, pktlen);

	px_memset(pkt, 0, pktlen);
	return res;
}

/*
 * key setup
 */
static int
init_s2k_key(PGP_Context *ctx)
{
	int			res;

	if (ctx->s2k_cipher_algo < 0)
		ctx->s2k_cipher_algo = ctx->cipher_algo;

	res = pgp_s2k_fill(&ctx->s2k, ctx->s2k_mode, ctx->s2k_digest_algo, ctx->s2k_count);
	if (res < 0)
		return res;

	return pgp_s2k_process(&ctx->s2k, ctx->s2k_cipher_algo,
						   ctx->sym_key, ctx->sym_key_len);
}

static int
init_sess_key(PGP_Context *ctx)
{
	if (ctx->use_sess_key || ctx->pub_key)
	{
		ctx->sess_key_len = pgp_get_cipher_key_size(ctx->cipher_algo);
		if (!pg_strong_random(ctx->sess_key, ctx->sess_key_len))
			return PXE_NO_RANDOM;
	}
	else
	{
		ctx->sess_key_len = ctx->s2k.key_len;
		memcpy(ctx->sess_key, ctx->s2k.key, ctx->s2k.key_len);
	}

	return 0;
}

/*
 * combine
 */
int
pgp_encrypt(PGP_Context *ctx, MBuf *src, MBuf *dst)
{
	int			res;
	int			len;
	uint8	   *buf;
	PushFilter *pf,
			   *pf_tmp;

	/*
	 * do we have any key
	 */
	if (!ctx->sym_key && !ctx->pub_key)
		return PXE_ARGUMENT_ERROR;

	/* MBuf writer */
	res = pushf_create_mbuf_writer(&pf, dst);
	if (res < 0)
		goto out;

	/*
	 * initialize sym_key
	 */
	if (ctx->sym_key)
	{
		res = init_s2k_key(ctx);
		if (res < 0)
			goto out;
	}

	res = init_sess_key(ctx);
	if (res < 0)
		goto out;

	/*
	 * write keypkt
	 */
	if (ctx->pub_key)
		res = pgp_write_pubenc_sesskey(ctx, pf);
	else
		res = write_symenc_sesskey(ctx, pf);
	if (res < 0)
		goto out;

	/* encrypted data pkt */
	res = init_encdata_packet(&pf_tmp, ctx, pf);
	if (res < 0)
		goto out;
	pf = pf_tmp;

	/* encrypter */
	res = pushf_create(&pf_tmp, &encrypt_filter, ctx, pf);
	if (res < 0)
		goto out;
	pf = pf_tmp;

	/* hasher */
	if (ctx->disable_mdc == 0)
	{
		res = pushf_create(&pf_tmp, &mdc_filter, ctx, pf);
		if (res < 0)
			goto out;
		pf = pf_tmp;
	}

	/* prefix */
	res = write_prefix(ctx, pf);
	if (res < 0)
		goto out;

	/* compressor */
	if (ctx->compress_algo > 0 && ctx->compress_level > 0)
	{
		res = init_compress(&pf_tmp, ctx, pf);
		if (res < 0)
			goto out;
		pf = pf_tmp;
	}

	/* data streamer */
	res = init_litdata_packet(&pf_tmp, ctx, pf);
	if (res < 0)
		goto out;
	pf = pf_tmp;


	/* text conversion? */
	if (ctx->text_mode && ctx->convert_crlf)
	{
		res = pushf_create(&pf_tmp, &crlf_filter, ctx, pf);
		if (res < 0)
			goto out;
		pf = pf_tmp;
	}

	/*
	 * chain complete
	 */

	len = mbuf_grab(src, mbuf_avail(src), &buf);
	res = pushf_write(pf, buf, len);
	if (res >= 0)
		res = pushf_flush(pf);
out:
	pushf_free_all(pf);
	return res;
}